Last data update: Nov 04, 2024. (Total: 48056 publications since 2009)
Records 1-30 (of 40 Records) |
Query Trace: Gangappa S[original query] |
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The frequency and function of nucleoprotein-specific CD8(+) T cells are critical for heterosubtypic immunity against influenza virus infection
Amoah S , Cao W , Sayedahmed EE , Wang Y , Kumar A , Mishina M , Eddins DJ , Wang WC , Burroughs M , Sheth M , Lee J , Shieh WJ , Ray SD , Bohannon CD , Ranjan P , Sharma SD , Hoehner J , Arthur RA , Gangappa S , Wakamatsu N , Johnston HR , Pohl J , Mittal SK , Sambhara S . J Virol 2024 e0071124 Cytotoxic T lymphocytes (CTLs) mediate host defense against viral and intracellular bacterial infections and tumors. However, the magnitude of CTL response and their function needed to confer heterosubtypic immunity against influenza virus infection are unknown. We addressed the role of CD8(+) T cells in the absence of any cross-reactive antibody responses to influenza viral proteins using an adenoviral vector expressing a 9mer amino acid sequence recognized by CD8(+) T cells. Our results indicate that both CD8(+) T cell frequency and function are crucial for heterosubtypic immunity. Low morbidity, lower viral lung titers, low to minimal lung pathology, and better survival upon heterosubtypic virus challenge correlated with the increased frequency of NP-specific CTLs. NP-CD8(+) T cells induced by differential infection doses displayed distinct RNA transcriptome profiles and functional properties. CD8(+) T cells induced by a high dose of influenza virus secreted significantly higher levels of IFN-γ and exhibited higher levels of cytotoxic function. The mice that received NP-CD8(+) T cells from the high-dose virus recipients through adoptive transfer had lower viral titers following viral challenge than those induced by the low dose of virus, suggesting differential cellular programming by antigen dose. Enhanced NP-CD8(+) T-cell functions induced by a higher dose of influenza virus strongly correlated with the increased expression of cellular and metabolic genes, indicating a shift to a more glycolytic metabolic phenotype. These findings have implications for developing effective T cell vaccines against infectious diseases and cancer. IMPORTANCE: Cytotoxic T lymphocytes (CTLs) are an important component of the adaptive immune system that clears virus-infected cells or tumor cells. Hence, developing next-generation vaccines that induce or recall CTL responses against cancer and infectious diseases is crucial. However, it is not clear if the frequency, function, or both are essential in conferring protection, as in the case of influenza. In this study, we demonstrate that both CTL frequency and function are crucial for providing heterosubtypic immunity to influenza by utilizing an Ad-viral vector expressing a CD8 epitope only to rule out the role of antibodies, single-cell RNA-seq analysis, as well as adoptive transfer experiments. Our findings have implications for developing T cell vaccines against infectious diseases and cancer. |
Redirecting antibody responses from egg-adapted epitopes following repeat vaccination with recombinant or cell culture-based versus egg-based influenza vaccines
Liu F , Gross FL , Joshi S , Gaglani M , Naleway AL , Murthy K , Groom HC , Wesley MG , Edwards LJ , Grant L , Kim SS , Sambhara S , Gangappa S , Tumpey T , Thompson MG , Fry AM , Flannery B , Dawood FS , Levine MZ . Nat Commun 2024 15 (1) 254 Repeat vaccination with egg-based influenza vaccines could preferentially boost antibodies targeting the egg-adapted epitopes and reduce immunogenicity to circulating viruses. In this randomized trial (Clinicaltrials.gov: NCT03722589), sera pre- and post-vaccination with quadrivalent inactivated egg-based (IIV4), cell culture-based (ccIIV4), and recombinant (RIV4) influenza vaccines were collected from healthcare personnel (18-64 years) in 2018-19 (N = 723) and 2019-20 (N = 684) influenza seasons. We performed an exploratory analysis. Vaccine egg-adapted changes had the most impact on A(H3N2) immunogenicity. In year 1, RIV4 induced higher neutralizing and total HA head binding antibodies to cell- A(H3N2) virus than ccIIV4 and IIV4. In year 2, among the 7 repeat vaccination arms (IIV4-IIV4, IIV4-ccIIV4, IIV4-RIV4, RIV4-ccIIV4, RIV4-RIV4, ccIIV4-ccIIV4 and ccIIV4-RIV4), repeat vaccination with either RIV4 or ccIIV4 further improved antibody responses to circulating viruses with decreased neutralizing antibody egg/cell ratio. RIV4 also had higher post-vaccination A(H1N1)pdm09 and A(H3N2) HA stalk antibodies in year 1, but there was no significant difference in HA stalk antibody fold rise among vaccine groups in either year 1 or year 2. Multiple seasons of non-egg-based vaccination may be needed to redirect antibody responses from immune memory to egg-adapted epitopes and re-focus the immune responses towards epitopes on the circulating viruses to improve vaccine effectiveness. |
The inflammatory response to birth requires MyD88 and is driven by both mother and offspring
Gray JM , Castillo-Ruiz A , Major KM , Shipley M , Gangappa S , Forger NG . Brain Behav Immun 2023 115 617-630 Birth is an inflammatory event for the newborn, characterized by elevations in interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α peripherally and/or centrally, as well as changes in brain microglia. However, the mechanism(s) underlying these responses is unknown. Toll-like receptors (TLRs) play crucial roles in innate immunity and initiate inflammatory cascades upon recognition of endogenous or exogenous antigens. Most TLR signaling depends on the adaptor molecule myeloid differentiation primary response 88 (MyD88). We independently varied MyD88 gene status in mouse dams and their offspring to determine whether the inflammatory response to birth depends on MyD88 signaling and, if so, whether that signaling occurs in the offspring, the mother, or both. We find that the perinatal surges in plasma IL-6 and brain expression of TNF-α depend solely on MyD88 gene status of the offspring, whereas postnatal increases in plasma IL-10 and TNF-α depend on MyD88 in both the pup and dam. Interestingly, MyD88 genotype of the dam primarily drives differences in offspring brain microglial density and has robust effects on developmental neuronal cell death. Milk cytokines were evaluated as a possible source of postnatal maternal influence; although we found high levels of CXCL1/GROα and several other cytokines in ingested post-partum milk, their presence did not require MyD88. Thus, the inflammatory response previously described in the late-term fetus and newborn depends on MyD88 (and, by extension, TLRs), with signaling in both the dam and offspring contributing. Unexpectedly, naturally-occuring neuronal cell death in the newborn is modulated primarily by maternal MyD88 gene status. |
Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes in COVID-19 convalescent plasma (preprint)
Voss WN , Hou YJ , Johnson NV , Kim JE , Delidakis G , Horton AP , Bartzoka F , Paresi CJ , Tanno Y , Abbasi SA , Pickens W , George K , Boutz DR , Towers DM , McDaniel JR , Billick D , Goike J , Rowe L , Batra D , Pohl J , Lee J , Gangappa S , Sambhara S , Gadush M , Wang N , Person MD , Iverson BL , Gollihar JD , Dye J , Herbert A , Baric RS , McLellan JS , Georgiou G , Lavinder JJ , Ippolito GC . bioRxiv 2020 Although humoral immunity is essential for control of SARS-CoV-2, the molecular composition, binding epitopes and effector functions of the immunoglobulin G (IgG) antibodies that circulate in blood plasma following infection are unknown. Proteomic deconvolution of the circulating IgG repertoire (Ig-Seq (1) ) to the spike ectodomain (S-ECD (2) ) in four convalescent study subjects revealed that the plasma response is oligoclonal and directed predominantly (>80%) to S-ECD epitopes that lie outside the receptor binding domain (RBD). When comparing antibodies directed to either the RBD, the N-terminal domain (NTD) or the S2 subunit (S2) in one subject, just four IgG lineages (1 anti-S2, 2 anti-NTD and 1 anti-RBD) accounted for 93.5% of the repertoire. Although the anti-RBD and one of the anti-NTD antibodies were equally potently neutralizing in vitro , we nonetheless found that the anti-NTD antibody was sufficient for protection to lethal viral challenge, either alone or in combination as a cocktail where it dominated the effect of the other plasma antibodies. We identified in vivo protective plasma anti-NTD antibodies in 3/4 subjects analyzed and discovered a shared class of antibodies targeting the NTD that utilize unmutated or near-germline IGHV1-24, the most electronegative IGHV gene in the human genome. Structural analysis revealed that binding to NTD is dominated by interactions with the heavy chain, accounting for 89% of the entire interfacial area, with germline residues uniquely encoded by IGHV1-24 contributing 20% (149 Å (2) ). Together with recent reports of germline IGHV1-24 antibodies isolated by B-cell cloning (3,4) our data reveal a class of shared IgG antibodies that are readily observed in convalescent plasma and underscore the role of NTD-directed antibodies in protection against SARS-CoV-2 infection. |
Immunogenicity of high-dose egg-based, recombinant, and cell culture-based influenza vaccines compared with standard-dose egg-based influenza vaccine among health care personnel aged 18-65 years in 2019-2020
Naleway AL , Kim SS , Flannery B , Levine MZ , Murthy K , Sambhara S , Gangappa S , Edwards LJ , Ball S , Grant L , Zunie T , Cao W , Gross FL , Groom H , Fry AM , Hunt D , Jeddy Z , Mishina M , Wesley MG , Spencer S , Thompson MG , Gaglani M , Dawood FS . Open Forum Infect Dis 2023 10 (6) ofad223 BACKGROUND: Emerging data suggest that second-generation influenza vaccines with higher hemagglutinin (HA) antigen content and/or different production methods may induce stronger antibody responses to HA than standard-dose egg-based influenza vaccines in adults. We compared antibody responses to high-dose egg-based inactivated (HD-IIV3), recombinant (RIV4), and cell culture-based (ccIIV4) vs standard-dose egg-based inactivated influenza vaccine (SD-IIV4) among health care personnel (HCP) aged 18-65 years in 2 influenza seasons (2018-2019, 2019-2020). METHODS: In the second trial season, newly and re-enrolled HCPs who received SD-IIV4 in season 1 were randomized to receive RIV4, ccIIV4, or SD-IIV4 or were enrolled in an off-label, nonrandomized arm to receive HD-IIV3. Prevaccination and 1-month-postvaccination sera were tested by hemagglutination inhibition (HI) assay against 4 cell culture propagated vaccine reference viruses. Primary outcomes, adjusted for study site and baseline HI titer, were seroconversion rate (SCR), geometric mean titers (GMTs), mean fold rise (MFR), and GMT ratios that compared vaccine groups to SD-IIV4. RESULTS: Among 390 HCP in the per-protocol population, 79 received HD-IIV3, 103 RIV4, 106 ccIIV4, and 102 SD-IIV4. HD-IIV3 recipients had similar postvaccination antibody titers compared with SD-IIV4 recipients, whereas RIV4 recipients had significantly higher 1-month-postvaccination antibody titers against vaccine reference viruses for all outcomes. CONCLUSIONS: HD-IIV3 did not induce higher antibody responses than SD-IIV4, but, consistent with previous studies, RIV4 was associated with higher postvaccination antibody titers. These findings suggest that recombinant vaccines rather than vaccines with higher egg-based antigen doses may provide improved antibody responses in highly vaccinated populations. |
Effect of repeat vaccination on immunogenicity of quadrivalent cell-culture and recombinant influenza vaccines among healthcare personnel aged 18-64 years: A randomized, open-label trial
Gaglani M , Kim SS , Naleway AL , Levine MZ , Edwards L , Murthy K , Dunnigan K , Zunie T , Groom H , Ball S , Jeddy Z , Hunt D , Wesley MG , Sambhara S , Gangappa S , Grant L , Cao W , Liaini Gross F , Mishina M , Fry AM , Thompson MG , Dawood FS , Flannery B . Clin Infect Dis 2022 76 (3) e1168-e1176 BACKGROUND: Antibody responses to non-egg-based standard-dose cell-culture influenza vaccine (containing 15 µg hemagglutinin (HA)/component) and recombinant vaccine (containing 45 µg HA/component) during consecutive seasons have not been studied in the United States. METHODS: In a randomized trial of immunogenicity of quadrivalent influenza vaccines among healthcare personnel (HCP) aged 18-64 years over two consecutive seasons, HCP who received recombinant-hemagglutinin (RIV) or cell-culture-based vaccine (ccIIV) during the first season (Y1) were re-randomized the second season of 2019-2020 (Y2) to receive ccIIV or RIV, resulting in four ccIIV-RIV combinations. In Y2, hemagglutination inhibition (HI) antibody titers against reference cell-grown vaccine viruses were compared in each ccIIV-RIV group with titers among HCP randomized both seasons to receive egg-based, standard-dose inactivated influenza vaccine (IIV), using geometric mean titer (GMT) ratios of Y2-post-vaccination titers. RESULTS: Y2 data from 414 HCPs were analyzed per-protocol. Compared to 60 IIV/IIV recipients, 74 RIV/RIV and 106 ccIIV/RIV recipients showed significantly elevated GMT ratios (Bonferroni corrected P <.007) against all components except A (H3N2). Post-vaccination GMT ratios for ccIIV/ccIIV and RIV/ccIIV were not significantly elevated compared to IIV/IIV except for RIV/ccIIV against A(H1N1)pdm09. CONCLUSIONS: In adult HCPs, receipt of RIV two consecutive seasons or the second season was more immunogenic than consecutive egg-based IIV for three of the four components of quadrivalent vaccine. Immunogenicity of ccIIV/ccIIV was similar to that of IIV/IIV. Differences in hemagglutinin antigen content may play a role in immunogenicity of influenza vaccination in consecutive seasons. |
Quinazolin-derived myeloperoxidase inhibitor suppresses influenza A virus-induced reactive oxygen species, pro-inflammatory mediators and improves cell survival
De La Cruz JA , Ganesh T , Diebold BA , Cao W , Hofstetter A , Singh N , Kumar A , McCoy J , Ranjan P , Smith SME , Sambhara S , Lambeth JD , Gangappa S . PLoS One 2021 16 (7) e0254632 Superoxide radicals and other reactive oxygen species (ROS) are implicated in influenza A virus-induced inflammation. In this in vitro study, we evaluated the effects of TG6-44, a novel quinazolin-derived myeloperoxidase-specific ROS inhibitor, on influenza A virus (A/X31) infection using THP-1 lung monocytic cells and freshly isolated peripheral blood mononuclear cells (PBMC). TG6-44 significantly decreased A/X31-induced ROS and virus-induced inflammatory mediators in THP-1 cells (IL-6, IFN-γ, MCP-1, TNF-α, MIP-1β) and in human PBMC (IL-6, IL-8, TNF-α, MCP-1). Interestingly, TG6-44-treated THP-1 cells showed a decrease in percent cells expressing viral nucleoprotein, as well as a delay in translocation of viral nucleoprotein into the nucleus. Furthermore, in influenza A virus-infected cells, TG6-44 treatment led to suppression of virus-induced cell death as evidenced by decreased caspase-3 activation, decreased proportion of Annexin V+PI+ cells, and increased Bcl-2 phosphorylation. Taken together, our results demonstrate the anti-inflammatory and anti-infective effects of TG6-44. |
Comparison of the Immunogenicity of Cell Culture-Based and Recombinant Quadrivalent Influenza Vaccines to Conventional Egg-Based Quadrivalent Influenza Vaccines among Healthcare Personnel Aged 18-64 Years: A Randomized Open-Label Trial
Dawood FS , Naleway AL , Flannery B , Levine MZ , Murthy K , Sambhara S , Gangappa S , Edwards L , Ball S , Beacham L , Belongia E , Bounds K , Cao W , Gross FL , Groom H , Fry AM , Hunt D , Jeddy Z , Mishina M , Kim SS , Wesley MG , Spencer S , Thompson MG , Gaglani M . Clin Infect Dis 2021 73 (11) 1973-1981 BACKGROUND: RIV4 and cell-culture based inactivated influenza vaccine (ccIIV4) have not been compared to egg-based IIV4 in healthcare personnel, a population with frequent influenza vaccination that may blunt vaccine immune responses over time. We conducted a randomized trial among HCP aged 18-64 years to compare humoral immune responses to ccIIV4 and RIV4 to IIV4. METHODS: During the 2018-2019 season, participants were randomized to receive ccIIV4, RIV4, or IIV4 and had sera collected pre-vaccination, 1 and 6 months post-vaccination. Sera were tested by hemagglutination inhibition (HI) for influenza A/H1N1, B/Yamagata, and B/Victoria and microneutralization (MN) for A/H3N2 against cell-grown vaccine reference viruses. Primary outcomes at 1 month were seroconversion rate (SCR), geometric mean titers (GMT), GMT ratio, and mean fold rise (MFR) in the intention-to-treat population. RESULTS: 727 participants were included (283 ccIIV4, 202 RIV4, and 242 IIV4). At 1 month, responses to ccIIV4 were similar to IIV4 by SCR, GMT, GMT ratio, and MFR. RIV4 induced higher SCRs, GMTs, and MFRs than IIV4 against A/H1N1, A/H3N2, and B/Yamagata. The GMT ratio of RIV4 to egg-based vaccines was 1.5 (95%CI 1.2-1.9) for A/H1N1, 3.0 (95%CI 2.4-3.7) for A/H3N2, 1.1 (95%CI 0.9-1.4) for B/Yamagata, and 1.1 (95%CI 0.9-1.3) for B/Victoria. At 6 months, ccIIV4 recipients had similar GMTs to IIV4, whereas RIV4 recipients had higher GMTs against A/H3N2 and B/Yamagata. CONCLUSION: RIV4 resulted in improved antibody responses by HI and MN compared to egg-based vaccines against three of four cell-grown vaccine strains 1 month post-vaccination, suggesting a possible additional benefit from RIV4. |
Influenza Virus Infects and Depletes Activated Adaptive Immune Responders
Bohannon CD , Ende Z , Cao W , Mboko WP , Ranjan P , Kumar A , Mishina M , Amoah S , Gangappa S , Mittal SK , Lovell JF , García-Sastre A , Pfeifer BA , Davidson BA , Knight P , Sambhara S . Adv Sci (Weinh) 2021 8 (16) e2100693 Influenza infections cause several million cases of severe respiratory illness, hospitalizations, and hundreds of thousands of deaths globally. Secondary infections are a leading cause of influenza's high morbidity and mortality, and significantly factored into the severity of the 1918, 1968, and 2009 pandemics. Furthermore, there is an increased incidence of other respiratory infections even in vaccinated individuals during influenza season. Putative mechanisms responsible for vaccine failures against influenza as well as other respiratory infections during influenza season are investigated. Peripheral blood mononuclear cells (PBMCs) are used from influenza vaccinated individuals to assess antigen-specific responses to influenza, measles, and varicella. The observations made in humans to a mouse model to unravel the mechanism is confirmed and extended. Infection with influenza virus suppresses an ongoing adaptive response to vaccination against influenza as well as other respiratory pathogens, i.e., Adenovirus and Streptococcus pneumoniae by preferentially infecting and killing activated lymphocytes which express elevated levels of sialic acid receptors. These findings propose a new mechanism for the high incidence of secondary respiratory infections due to bacteria and other viruses as well as vaccine failures to influenza and other respiratory pathogens even in immune individuals due to influenza viral infections. |
Prevalent, protective, and convergent IgG recognition of SARS-CoV-2 non-RBD spike epitopes.
Voss WN , Hou YJ , Johnson NV , Delidakis G , Kim JE , Javanmardi K , Horton AP , Bartzoka F , Paresi CJ , Tanno Y , Chou CW , Abbasi SA , Pickens W , George K , Boutz DR , Towers DM , McDaniel JR , Billick D , Goike J , Rowe L , Batra D , Pohl J , Lee J , Gangappa S , Sambhara S , Gadush M , Wang N , Person MD , Iverson BL , Gollihar JD , Dye J , Herbert A , Finkelstein IJ , Baric RS , McLellan JS , Georgiou G , Lavinder JJ , Ippolito GC . Science 2021 372 (6546) 1108-1112 The molecular composition and binding epitopes of the immunoglobulin G (IgG) antibodies that circulate in blood plasma following SARS-CoV-2 infection are unknown. Proteomic deconvolution of the IgG repertoire to the spike glycoprotein in convalescent subjects revealed that the response is directed predominantly (>80%) against epitopes residing outside the receptor-binding domain (RBD). In one subject, just four IgG lineages accounted for 93.5% of the response, including an N-terminal domain (NTD)-directed antibody that was protective against lethal viral challenge. Genetic, structural, and functional characterization of a multi-donor class of "public" antibodies revealed an NTD epitope that is recurrently mutated among emerging SARS-CoV-2 variants of concern. These data show that "public" NTD-directed and other non-RBD plasma antibodies are prevalent and have implications for SARS-CoV-2 protection and antibody escape. |
Immunogenicity of standard, high-dose, MF59-adjuvanted, and recombinant-HA seasonal influenza vaccination in older adults
Li APY , Cohen CA , Leung NHL , Fang VJ , Gangappa S , Sambhara S , Levine MZ , Iuliano AD , Perera Rapm , Ip DKM , Peiris JSM , Thompson MG , Cowling BJ , Valkenburg SA . NPJ Vaccines 2021 6 (1) 25 The vaccine efficacy of standard-dose seasonal inactivated influenza vaccines (S-IIV) can be improved by the use of vaccines with higher antigen content or adjuvants. We conducted a randomized controlled trial in older adults to compare cellular and antibody responses of S-IIV versus enhanced vaccines (eIIV): MF59-adjuvanted (A-eIIV), high-dose (H-eIIV), and recombinant-hemagglutinin (HA) (R-eIIV). All vaccines induced comparable H3-HA-specific IgG and elevated antibody-dependent cellular cytotoxicity (ADCC) activity at day 30 post vaccination. H3-HA-specific ADCC responses were greatest following H-eIIV. Only A-eIIV increased H3-HA-IgG avidity, HA-stalk IgG and ADCC activity. eIIVs also increased polyfunctional CD4+ and CD8+ T cell responses, while cellular immune responses were skewed toward single-cytokine-producing T cells among S-IIV subjects. Our study provides further immunological evidence for the preferential use of eIIVs in older adults as each vaccine platform had an advantage over the standard-dose vaccine in terms of NK cell activation, HA-stalk antibodies, and T cell responses. |
A dual-functioning 5'-PPP-NS1shRNA that activates a RIG-I antiviral pathway and suppresses influenza NS1
Singh N , Ranjan P , Cao W , Patel J , Gangappa S , Davidson BA , Sullivan JM , Prasad PN , Knight PR , Sambhara S . Mol Ther Nucleic Acids 2020 19 1413-1422 Retinoic acid-inducible gene-I (RIG-I) is a cytosolic pathogen sensor that is crucial against a number of viral infections. Many viruses have evolved to inhibit pathogen sensors to suppress host innate immune responses. In the case of influenza, nonstructural protein 1 (NS1) suppresses RIG-I function, leading to viral replication, morbidity, and mortality. We show that silencing NS1 with in-vitro-transcribed 5'-triphosphate containing NS1 short hairpin RNA (shRNA) (5'-PPP-NS1shRNA), designed using the conserved region of a number of influenza viruses, not only prevented NS1 expression but also induced RIG-I activation and type I interferon (IFN) expression, resulting in an antiviral state leading to inhibition of influenza virus replication in vitro. In addition, administration of 5'-PPP-NS1shRNA in prophylactic and therapeutic settings resulted in significant inhibition of viral replication following viral challenge in vivo in mice with corresponding increases of RIG-I, IFN-beta, and IFN-lambda, as well as a decrease in NS1 expression. |
Influenza virus NS1- C/EBPβ gene regulatory complex inhibits RIG-I transcription.
Kumari R , Guo Z , Kumar A , Wiens M , Gangappa S , Katz JM , Cox NJ , Lal RB , Sarkar D , Fisher PB , Garcia-Sastre A , Fujita T , Kumar V , Sambhara S , Ranjan P , Lal SK . Antiviral Res 2020 176 104747 Influenza virus non-structural protein 1 (NS1) counteracts host antiviral innate immune responses by inhibiting Retinoic acid inducible gene-I (RIG-I) activation. However, whether NS1 also specifically regulates RIG-I transcription is unknown. Here, we identify a CCAAT/Enhancer Binding Protein beta (C/EBPbeta) binding site in the RIG-I promoter as a repressor element, and show that NS1 promotes C/EBPbeta phosphorylation and its recruitment to the RIG-I promoter as a C/EBPbeta/NS1 complex. C/EBPbeta overexpression and siRNA knockdown in human lung epithelial cells resulted in suppression and activation of RIG-I expression respectively, implying a negative regulatory role of C/EBPbeta. Further, C/EBPbeta phosphorylation, its interaction with NS1 and occupancy at the RIG-I promoter was associated with RIG-I transcriptional inhibition. These findings provide an important insight into the molecular mechanism by which influenza NS1 commandeers RIG-I transcriptional regulation and suppresses host antiviral responses. |
Comparative immunogenicity of several enhanced influenza vaccine options for older adults: A randomized, controlled trial
Cowling BJ , Perera Rapm , Valkenburg SA , Leung NHL , Iuliano AD , Tam YH , Wong JHF , Fang VJ , Li APY , So HC , Ip DKM , Azziz-Baumgartner E , Fry AM , Levine MZ , Gangappa S , Sambhara S , Barr IG , Skowronski DM , Peiris JSM , Thompson MG . Clin Infect Dis 2019 71 (7) 1704-1714 BACKGROUND: Enhanced influenza vaccines may improve protection for older adults, but comparative immunogenicity data are limited. Our objective was to examine immune responses to enhanced influenza vaccines, compared to standard-dose vaccines, in community-dwelling older adults. METHODS: Community-dwelling older adults aged 65-82 years in Hong Kong were randomly allocated (October 2017-January 2018) to receive 2017-2018 Northern hemisphere formulations of a standard-dose quadrivalent vaccine, MF59-adjuvanted trivalent vaccine, high-dose trivalent vaccine, or recombinant-hemagglutinin (rHA) quadrivalent vaccine. Sera collected from 200 recipients of each vaccine before and at 30-days postvaccination were assessed for antibodies to egg-propagated vaccine strains by hemagglutination inhibition (HAI) and to cell-propagated A/Hong Kong/4801/2014(H3N2) virus by microneutralization (MN). Influenza-specific CD4+ and CD8+ T cell responses were assessed in 20 participants per group. RESULTS: Mean fold rises (MFR) in HAI titers to egg-propagated A(H1N1) and A(H3N2) and the MFR in MN to cell-propagated A(H3N2) were statistically significantly higher in the enhanced vaccine groups, compared to the standard-dose vaccine. The MFR in MN to cell-propagated A(H3N2) was highest among rHA recipients (4.7), followed by high-dose (3.4) and MF59-adjuvanted (2.9) recipients, compared to standard-dose recipients (2.3). Similarly, the ratio of postvaccination MN titers among rHA recipients to cell-propagated A(H3N2) recipients was 2.57-fold higher than the standard-dose vaccine, which was statistically higher than the high-dose (1.33-fold) and MF59-adjuvanted (1.43-fold) recipient ratios. Enhanced vaccines also resulted in the boosting of T-cell responses. CONCLUSIONS: In this head-to-head comparison, older adults receiving enhanced vaccines showed improved humoral and cell-mediated immune responses, compared to standard-dose vaccine recipients. CLINICAL TRIALS REGISTRATION: NCT03330132. |
Standard-dose intradermal influenza vaccine elicits cellular immune responses similar to those of intramuscular vaccine in men with and those without HIV infection
Amoah S , Mishina M , Praphasiri P , Cao W , Kim JH , Liepkalns JS , Guo Z , Carney PJ , Chang JC , Fernandez S , Garg S , Beacham L , Holtz TH , Curlin ME , Dawood F , Olsen SJ , Gangappa S , Stevens J , Sambhara S . J Infect Dis 2019 220 (5) 743-751 BACKGROUND: Human immunodeficiency virus (HIV)-infected persons are at a higher risk of severe influenza. Although we have shown that a standard-dose intradermal influenza vaccine versus a standard-dose intramuscular influenza vaccine does not result in differences in hemagglutination-inhibition titers in this population, a comprehensive examination of cell-mediated immune responses remains lacking. METHODS: Serological, antigen-specific B-cell, and interleukin 2-, interferon gamma-, and tumor necrosis factor alpha-secreting T-cell responses were assessed in 79 HIV-infected men and 79 HIV-uninfected men. RESULTS: The route of vaccination did not affect the immunoglobulin A and immunoglobulin G (IgG) plasmablast or memory B-cell response, although these were severely impaired in the group with a CD4+ T-cell count of <200 cells/muL. The frequencies of IgG memory B cells measured on day 28 after vaccination were highest in the HIV-uninfected group, followed by the group with a CD4+ T-cell count of >/=200 cells/muL and the group with a CD4+ T-cell count of <200 cells/muL. The route of vaccination did not affect the CD4+ or CD8+ T-cell responses measured at various times after vaccination. CONCLUSIONS: The route of vaccination had no effect on antibody responses, antibody avidity, T-cell responses, or B-cell responses in HIV-infected or HIV-uninfected subjects. With the serological and cellular immune responses to influenza vaccination being impaired in HIV-infected individuals with a CD4+ T-cell count of <200 cells/muL, passive immunization strategies need to be explored to protect this population. CLINICAL TRIALS REGISTRATION: NCT01538940. |
Kinetics of antibody response to influenza vaccination in renal transplant recipients
Gangappa S , Wrammert J , Wang D , Li ZN , Liepkalns JS , Cao W , Chen J , Levine MZ , Stevens J , Sambhara S , Begley B , Mehta A , Pearson TC , Ahmed R , Larsen CP . Transpl Immunol 2019 53 51-60 Annual vaccination is routinely used in organ transplant recipients for immunization against seasonal influenza. However, detailed analysis of the kinetics of vaccine-induced immune responses in this population is lacking. In this study, we investigated the kinetics of vaccine strains-specific antibody responses to trivalent influenza vaccine in a group of renal transplant recipients and a control group. First, we found that the geometric mean hemagglutination inhibition titer against all 3 vaccine strains in the transplant cohort was significantly low when compared to control subjects. Next, whereas the control group sera showed significantly higher HA-specific IgG and isotype IgG1 antibodies at all four time points, a similar increase in the transplant group was delayed until day 28. Interestingly, within the transplant group, subjects receiving belatacept/MMF/prednisone-based regimen had significantly lower levels of total IgG and HA-specific IgG when compared to tacrolimus/MMF/prednisone-based regimen. Even though IgG-ASC response in both cohorts peaked at day 7 post-vaccination, the frequency of IgG-ASC was significantly low in the transplant group. Taken together, our studies show delayed kinetics and lower levels of influenza vaccine-specific antibody responses in renal transplant recipients and, more importantly, indicate the need to probe and improve current vaccination strategies in renal transplant recipients. |
Longevity of adenovirus vector immunity in mice and its implications for vaccine efficacy
Sayedahmed EE , Kumari R , Shukla S , Hassan AO , Mohammed SI , York IA , Gangappa S , Sambhara S , Mittal SK . Vaccine 2018 36 (45) 6744-6751 There is a high incidence of adenovirus (AdV) infection in humans due to the presence of more than 60 types of human adenoviruses (HAdVs). The majority of individuals are exposed to one or more HAdV types early in their lives, leading to the development of AdV type-specific neutralizing antibodies. Similarly, immunization or gene therapy with AdV vectors leads to immune responses to the AdV vector. This 'vector immunity' is a concern for AdV vector-based applications for vaccines or gene therapy, especially when the repeated administration of a vector is required. The objective of this investigation was to establish whether AdV neutralizing antibody titers decline sufficiently in a year to permit annual vaccination with the same AdV vector. Naive or human adenoviral vector group C, type 5 (HAdV-C5)-primed mice were mock-inoculated (with PBS) or inoculated i.m. with 10(8)PFU of either HAd-GFP [HAdV-C5 vector expressing the green fluorescent protein (GFP)] to mimic the conditions for the first inoculation with an AdV vector-based vaccine. At 1, 3, 6, and 10months post-HAd-GFP inoculation, naive- or HAdV-primed animals were vaccinated i.m. with 10(8)PFU of HAd-H5HA [HAdV-C5 vector expressing hemagglutinin (HA) of H5N1 influenza virus]. There was a significant continual decrease in vector immunity titers with time, thereby leading to significant continual increases in the levels of HA-specific humoral and cell-mediated immune responses. In addition, significant improvement in protection efficacy against challenge with an antigenically heterologous H5N1 virus was observed in HAdV-primed animals at 6months and onwards. These results indicate that the annual immunization with the same AdV vector may be effective due to a significant decline in vector immunity. |
A bovine adenoviral vector-based H5N1 influenza -vaccine provides enhanced immunogenicity and protection at a significantly low dose
Sayedahmed EE , Hassan AO , Kumari R , Cao W , Gangappa S , York I , Sambhara S , Mittal SK . Mol Ther Methods Clin Dev 2018 10 210-222 Several human and nonhuman adenovirus (AdV) vectors including bovine AdV type 3 (BAdV-3) were developed as gene delivery vectors to supplement and/or elude human AdV (HAdV)-specific neutralizing antibodies (vector immunity). Here we evaluated the vaccine immunogenicity and efficacy of BAdV-3 vector (BAd-H5HA) expressing hemagglutinin (HA) of a H5N1 influenza virus in a dose escalation study in mice with the intranasal (IN) or intramuscular (IM) route of inoculation in comparison with the HAdV type C5 (HAdV-C5) vector (HAd-H5HA) expressing HA of a H5N1 influenza virus. Dose-related increases in the immune responses were clearly noticeable. A single IM inoculation with BAd-H5HA resulted in enhanced cellular immune responses compared with that of HAd-H5HA and conferred complete protection following challenge with a heterologous H5N1 virus at the dose of 3 x 10(7) plaque-forming units (PFUs), whereas a significant amount of influenza virus was detected in the lungs of mice immunized with 1 x 10(8) PFUs of HAd-H5HA. Similarly, compared with that of HAd-H5HA, a single IN inoculation with BAd-H5HA produced significantly enhanced humoral (HA-specific immunoglobulin [IgG] and its subclasses, as well as HA-specific IgA) and cellular immune responses, and conferred complete protection following challenge with a heterologous H5N1 virus. Complete protection with BAd-H5HA was observed with the lowest vaccine dose (1 x 10(6) PFUs), but similar protection with HAd-H5HA was observed at the highest vaccine dose (1 x 10(8) PFUs). These results suggest that at least 30-fold dose sparing can be achieved with BAd-H5HA vector compared with HAd-H5HA vaccine vector. |
Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet or in vivo-jetPEI((R)) induces enhanced serological, cellular and protective immune responses
Cao W , Mishina M , Amoah S , Mboko WP , Bohannon C , McCoy J , Mittal SK , Gangappa S , Sambhara S . Drug Deliv 2018 25 (1) 773-779 Avian influenza virus infection is a serious public health threat and preventive vaccination is the most cost-effective public health intervention strategy. Unfortunately, currently available unadjuvanted avian influenza vaccines are poorly immunogenic and alternative vaccine formulations and delivery strategies are in urgent need to reduce the high risk of avian influenza pandemics. Cationic polymers have been widely used as vectors for gene delivery in vitro and in vivo. In this study, we formulated H5N1 influenza vaccines with GenJet or in vivo-jetPEI((R)), and showed that these formulations significantly enhanced the immunogenicity of H5N1 vaccines and conferred protective immunity in a mouse model. Detailed analyses of adaptive immune responses revealed that both formulations induced mixed TH1/TH2 antigen-specific CD4 T-cell responses, antigen-specific cytotoxic CD8 T-cell and memory B-cell responses. Our findings suggest that cationic polymers merit future development as potential adjuvants for mucosal delivery of poorly immunogenic vaccines. |
Adenovirus vector-based multi-epitope vaccine provides partial protection against H5, H7, and H9 avian influenza viruses.
Hassan AO , Amen O , Sayedahmed EE , Vemula SV , Amoah S , York I , Gangappa S , Sambhara S , Mittal SK . PLoS One 2017 12 (10) e0186244 The emergence of H5, H7, and H9 avian influenza virus subtypes in humans reveals their pandemic potential. Although human-to-human transmission has been limited, the genetic reassortment of the avian and human/porcine influenza viruses or mutations in some of the genes resulting in virus replication in the upper respiratory tract of humans could generate novel pandemic influenza viruses. Current vaccines do not provide cross protection against antigenically distinct strains of the H5, H7, and H9 influenza viruses. Therefore, newer vaccine approaches are needed to overcome these potential threats. We developed an egg-independent, adenovirus vector-based, multi-epitope (ME) vaccine approach using the relatively conserved immunogenic domains of the H5N1 influenza virus [M2 ectodomain (M2e), hemagglutinin (HA) fusion domain (HFD), T-cell epitope of nucleoprotein (TNP). and HA alpha-helix domain (HalphaD)]. Our ME vaccine induced humoral and cell-mediated immune responses and caused a significant reduction in the viral loads in the lungs of vaccinated mice that were challenged with antigenically distinct H5, H7, or H9 avian influenza viruses. These results suggest that our ME vaccine approach provided broad protection against the avian influenza viruses. Further improvement of this vaccine will lead to a pre-pandemic vaccine that may lower morbidity, hinder transmission, and prevent mortality in a pandemic situation before a strain-matched vaccine becomes available. |
An adjuvanted A(H5N1) subvirion vaccine elicits virus-specific antibody response and improves protection against lethal influenza viral challenge in mouse model of protein energy malnutrition
Jones EN , Amoah S , Cao W , Sambhara S , Gangappa S . J Infect Dis 2017 216 S560-s565 Background: Protein energy malnutrition (PEM) increases susceptibility to infectious diseases, including influenza infection, but no studies have addressed the potential influences of PEM on the immunogenicity and protective efficacy of avian influenza A(H5N1) vaccine. Methods: We investigated the role of PEM on vaccine-mediated protection after a lethal challenge with recombinant A(H5N1) virus using isocaloric diets providing either adequate protein (AP; 18% protein) or very low protein (VLP; 2% protein) in an established murine model of influenza vaccination. Results: We demonstrated that mice maintained on a VLP diet succumb to lethal challenge at greater rates than mice maintained on an AP diet, despite comparable immunization regimens. Importantly, there was no virus-induced mortality in both VLP and AP groups of mice when either group was immunized with adjuvanted low-dose A(H5N1) subvirion vaccine. Conclusions: Our results suggest that adjuvanted vaccination in populations where PEM is endemic may be one strategy to boost vaccination-promoted immunity and improve outcomes associated with highly pathogenic A(H5N1). |
Nasal delivery of Protollin-adjuvanted H5N1 vaccine induces enhanced systemic as well as mucosal immunity in mice
Cao W , Kim JH , Reber AJ , Hoelscher M , Belser JA , Lu X , Katz JM , Gangappa S , Plante M , Burt DS , Sambhara S . Vaccine 2017 35 (25) 3318-3325 Sporadic, yet frequent human infections with avian H5N1 influenza A viruses continue to pose a potential pandemic threat. Poor immunogenicity of unadjuvanted H5N1 vaccines warrants developing novel adjuvants and formulations as well as alternate delivery systems to improve their immunogenicity and efficacy. Here, we show that Protollin, a nasal adjuvant composed of Neisseria meningitides outer membrane proteins non-covalently linked to Shigella flexneri 2a lipopolysaccharide, is a potent nasal adjuvant for an inactivated split virion H5N1 clade 1 A/Viet Nam1203/2004 (A/VN/1203/04) vaccine in a mouse model. Protollin-adjuvanted vaccines elicited enhanced serum protective hemagglutination inhibition titers, mucosal IgA responses, and H5N1-specific cell-mediated immunity that resulted in complete protection against a lethal challenge with a homologous virus as well as a heterologous clade 2 virus A/Indonesia/05/2005 (A/IN/05/05). Detailed analysis of adaptive immunity revealed that Protollin increased the frequency of lymphoid- as well as local tissue-resident antibody-secreting cells, local germinal center reaction of B cells, broad-spectrum of CD4 T cell response. Our findings suggest that nasal delivery of H5N1 vaccine with Protollin adjuvant can overcome the poor immunogenicity of H5N1 vaccines, induce both cellular and humoral immune responses, enhance protection against challenge with clade 1 and clade 2 H5N1 viruses and achieve significant antigen dose-sparing. |
Influenza virus exploits tunneling nanotubes for cell-to-cell spread.
Kumar A , Kim JH , Ranjan P , Metcalfe MG , Cao W , Mishina M , Gangappa S , Guo Z , Boyden ES , Zaki S , York I , Garcia-Sastre A , Shaw M , Sambhara S . Sci Rep 2017 7 40360 Tunneling nanotubes (TNTs) represent a novel route of intercellular communication. While previous work has shown that TNTs facilitate the exchange of viral or prion proteins from infected to naive cells, it is not clear whether the viral genome is also transferred via this mechanism and further, whether transfer via this route can result in productive replication of the infectious agents in the recipient cell. Here we present evidence that lung epithelial cells are connected by TNTs, and in spite of the presence of neutralizing antibodies and an antiviral agent, Oseltamivir, influenza virus can exploit these networks to transfer viral proteins and genome from the infected to naive cell, resulting in productive viral replication in the naive cells. These observations indicate that influenza viruses can spread using these intercellular networks that connect epithelial cells, evading immune and antiviral defenses and provide an explanation for the incidence of influenza infections even in influenza-immune individuals and vaccine failures. |
Rapamycin does not impede survival or induction of antibody responses to primary and heterosubtypic influenza infections in mice
Liepkalns JS , Pandey A , Hofstetter AR , Kumar A , Jones EN , Cao W , Liu F , Levine MZ , Sambhara S , Gangappa S . Viral Immunol 2016 29 (8) 487-493 Impairment of immune defenses can contribute to severe influenza infections. Rapamycin is an immunosuppressive drug often used to prevent transplant rejection and is currently undergoing clinical trials for treating cancers and autoimmune diseases. We investigated whether rapamycin has deleterious effects during lethal influenza viral infections. We treated mice with two concentrations of rapamycin and infected them with A/Puerto Rico/8/1934 (A/PR8), followed by a heterosubtypic A/Hong Kong/1/68 (A/HK68) challenge. Our data show similar morbidity, mortality, and lung viral titer with both rapamycin treatment doses compared to untreated controls, with a delay in morbidity onset in rapamycin high dose recipients during primary infection. Rapamycin treatment at high dose also led to increase in percent cytokine producing T cells in the spleen. However, all infected animals had similar serum antibody responses against A/PR8. Post-A/HK68 challenge, rapamycin had no impeding effect on morbidity or mortality and had similar serum antibody levels against A/PR8 and A/HK68. We conclude that rapamycin treatment does not adversely affect morbidity, mortality, or antibody production during lethal influenza infections. |
RIG-I ligand enhances the immunogenicity of recombinant H7HA protein
Cao W , Liepkalns JS , Kamal RP , Reber AJ , Kim JH , Hofstetter AR , Amoah S , Stevens J , Ranjan P , Gangappa S , York IA , Sambhara S . Cell Immunol 2016 304-305 55-8 Avian H7N9 influenza virus infection with fatal outcomes continues to pose a pandemic threat and highly immunogenic vaccines are urgently needed. In this report we show that baculovirus-derived recombinant H7 hemagglutinin protein, when delivered with RIG-I ligand, induced enhanced antibody and T cell responses and conferred protection against lethal challenge with a homologous H7N9 virus. These findings indicate the potential utility of RIG-I ligands as vaccine adjuvants to increase the immunogenicity of recombinant H7 hemagglutinin. |
An oil-in-water nanoemulsion enhances immunogenicity of H5N1 vaccine in mice
Cao W , Davis WG , Kim JH , De La Cruz JA , Taylor A , Hendrickson GR , Kumar A , Ranjan P , Lyon LA , Katz JM , Gangappa S , Sambhara S . Nanomedicine 2016 12 (7) 1909-1917 To enhance the immunogenicity of the Influenza H5N1 vaccine, we developed an oil-in-water nanoemulsion (NE) adjuvant. NE displayed good temperature stability and maintained particle size. More importantly, it significantly enhanced IL-6 and MCP-1 production to recruit innate cells, including neutrophils, monocytes/macrophages and dendritic cells to the local environment. Furthermore, NE enhanced dendritic cell function to induce robust antigen-specific T and B cell immune responses. NE-adjuvanted H5N1 vaccine not only elicited significantly higher and long-lasting antibody responses, but also conferred enhanced protection against homologous clade 1 as well as heterologous clade 2 H5N1 virus challenge in young as well as in aged mice. The pre-existing immunity to seasonal influenza did not affect the immunogenicity of NE-adjuvanted H5N1 vaccine. |
NADPH oxidase 1 is associated with altered host survival and t cell phenotypes after influenza A virus infection in mice
Hofstetter AR , De La Cruz JA , Cao W , Patel J , Belser JA , McCoy J , Liepkalns JS , Amoah S , Cheng G , Ranjan P , Diebold BA , Shieh WJ , Zaki S , Katz JM , Sambhara S , Lambeth JD , Gangappa S . PLoS One 2016 11 (2) e0149864 The role of the reactive oxygen species-producing NADPH oxidase family of enzymes in the pathology of influenza A virus infection remains enigmatic. Previous reports implicated NADPH oxidase 2 in influenza A virus-induced inflammation. In contrast, NADPH oxidase 1 (Nox1) was reported to decrease inflammation in mice within 7 days post-influenza A virus infection. However, the effect of NADPH oxidase 1 on lethality and adaptive immunity after influenza A virus challenge has not been explored. Here we report improved survival and decreased morbidity in mice with catalytically inactive NADPH oxidase 1 (Nox1*/Y) compared with controls after challenge with A/PR/8/34 influenza A virus. While changes in lung inflammation were not obvious between Nox1*/Y and control mice, we observed alterations in the T cell response to influenza A virus by day 15 post-infection, including increased interleukin-7 receptor-expressing virus-specific CD8+ T cells in lungs and draining lymph nodes of Nox1*/Y, and increased cytokine-producing T cells in lungs and spleen. Furthermore, a greater percentage of conventional and interstitial dendritic cells from Nox1*/Y draining lymph nodes expressed the co-stimulatory ligand CD40 within 6 days post-infection. Results indicate that NADPH oxidase 1 modulates the innate and adaptive cellular immune response to influenza virus infection, while also playing a role in host survival. Results suggest that NADPH oxidase 1 inhibitors may be beneficial as adjunct therapeutics during acute influenza infection. |
A highly immunogenic vaccine against A(H7N9) influenza virus
Cao W , Liepkalns J , Hassan AO , Kamal R , Hofstetter AR , Amoah S , Kim JH , Reber A , Stevens J , Katz JM , Gangappa S , York I , Mittal SK , Sambhara S . Vaccine 2016 34 (6) 744-9 Since the first case of human infection in March 2013, continued reports of H7N9 cases highlight a potential pandemic threat. Highly immunogenic vaccines to this virus are urgently needed to protect vulnerable populations who lack protective immunity. In this study, an egg- and adjuvant-independent adenoviral vector-based, hemagglutinin H7 subtype influenza vaccine (HAd-H7HA) demonstrated enhanced cell-mediated immunity as well as serum antibody responses in a mouse model. Most importantly, this vaccine provided complete protection against homologous A/(H7N9) viral challenge suggesting its potential utility as a pandemic vaccine. |
Increased dietary salt intake does not influence influenza A virus-induced disease severity in mice
Amoah S , Cao W , Ranjan P , Greer P , Shieh WJ , Zaki SR , Katz JM , Sambhara S , Gangappa S . Viral Immunol 2015 28 (9) 532-7 Influenza viruses are pathogens of significant public health importance. The influence of nutritional status on severity of disease has become increasingly recognized. In particular, high dietary salt intake has been linked to cardiovascular disease, but the effects on infectious diseases have not been studied. This study investigated the impact on influenza-induced morbidity and mortality in mice fed isocaloric diets containing 10-fold increments of sodium by altering the salt levels. Following infection, despite higher levels of IFN-gamma cytokine in the lung as well as virus-neutralizing antibody in the serum of mice fed the lowest salt level, the amounts of dietary salt intake had no substantial impact on the disease severity or the ability to respond immunologically to the infection. |
A Newly Emerged Swine-Origin Influenza A(H3N2) Variant Dampens Host Antiviral Immunity but Induces Potent Inflammasome Activation
Cao W , Mishina M , Ranjan P , De La Cruz JA , Kim JH , Garten R , Kumar A , Garcia-Sastre A , Katz JM , Gangappa S , Sambhara S . J Infect Dis 2015 212 (12) 1923-9 We compared the innate immune response to newly emerged swine origin H3N2 influenza A variant virus containing the M gene from A(H1N1)pdm09 virus (A(H3N2)vpm), with 2010 swine-origin A(H3N2)v and seasonal A(H3N2) viruses. Our results demonstrated that A(H3N2)vpM virus-induced myeloid dendritic cells secreted significantly lower levels of type I interferon (IFN) but produced significantly higher levels of pro-inflammatory cytokines and induced potent inflammasome activation. The reduction in antiviral immunity with increased inflammatory responses upon A(H3N2)vpM virus infection suggest that these viruses have the potential for increased disease severity in susceptible hosts. |
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