Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Patton TG[original query] |
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Evaluation of the Borrelia burgdorferi BBA64 protein as a protective immunogen in mice
Brandt KS , Patton TG , Allard AS , Caimano MJ , Radolf JD , Gilmore RD . Clin Vaccine Immunol 2014 21 (4) 526-33 The Borrelia burgdorferi bba64 gene product is a surface localized lipoprotein synthesized within mammalian and tick hosts and is involved in vector transmission. These properties suggest that BBA64 may be a vaccine candidate against Lyme borreliosis. Protective immunity against B. burgdorferi challenge was assessed in mice immunized with BBA64 protein. Mice developed a high-titered antibody response following immunization with soluble recombinant BBA64, but were not protected when challenged by needle inoculation of culture-grown spirochetes. Likewise, mice passively immunized with an anti-BBA64 monoclonal antibody were not protected against needle-inoculated organisms. BBA64-immunized mice were subjected to B. burgdorferi challenge by the natural route of tick bite, but these trials did not demonstrate significant protective immunity in either outbred or inbred strains of mice. Lipidated recombinant BBA64 produced in E. coli was assessed for improved elicitation of a protective immune response. Although inoculation with this antigen produced a high titered antibody response, the lipidated BBA64 also was unsuccessful in protecting mice from B. burgdorferi challenge by tick bite. Anti-BBA64 antibodies raised in rats eradicated the organisms by in vitro borreliacidal assays, thus demonstrating the potential for BBA64 to be effective as a protective immunogen. However, passive immunization with the same monospecific rat anti-BBA64 polyclonal serum failed to provide protection against tick-bite administered challenge. These results reveal the challenges faced to not only identify B. burgdorferi proteins with potential protective capability, but also to produce recombinant antigens conducive to preventive therapies against Lyme borreliosis. |
Borrelia burgdorferi bba66 gene inactivation results in attenuated mouse infection by tick transmission.
Patton TG , Brandt KS , Nolder C , Clifton DR , Carroll JA , Gilmore RD . Infect Immun 2013 81 (7) 2488-98 The impact of the Borrelia burgdorferi surface-localized immunogenic lipoprotein BBA66 on vector and host infection was evaluated by inactivating the encoding gene, bba66, and characterizing the mutant phenotype throughout the natural mouse-tick-mouse cycle. The BBA66-deficient mutant isolate, Bb(DeltaA66), remained infectious in mice by needle inoculation of cultured organisms, but differences in spirochete burden and pathology in the tibiotarsal joint were observed relative to the parental wild-type (WT) strain. Ixodes scapularis larvae successfully acquired Bb(DeltaA66) following feeding on infected mice, and the organisms persisted in these ticks through the molt to nymphs. A series of tick transmission experiments (n = 7) demonstrated that the ability of Bb(DeltaA66)-infected nymphs to infect laboratory mice was significantly impaired compared to that of mice fed upon by WT-infected ticks. trans-complementation of Bb(DeltaA66) with an intact copy of bba66 restored the WT infectious phenotype in mice via tick transmission. These results suggest a role for BBA66 in facilitating B. burgdorferi dissemination and transmission from the tick vector to the mammalian host as part of the disease process for Lyme borreliosis. |
Borrelia burgdorferi visualized in Ixodes scapularis tick excrement by immunofluorescence
Patton TG , Brandt KS , Gilmore RD Jr . Vector Borne Zoonotic Dis 2012 12 (11) 1000-3 The enzootic cycle of Borrelia burgdorferi, the etiologic agent of Lyme disease, involves Ixodes spp. ticks and vertebrates. Resident tick Borrelia, harbored inside the midgut, are eventually expelled with the tick's saliva into the vertebrate host when a tick consumes a blood meal. During this 4- to 5-day feeding period I. scapularis will defecate onto the host's skin. Previously we detected borrelial DNA in tick feces throughout engorgement. In this study we report the microscopic examination for B. burgdorferi in nymphal excrement. Using immunofluorescence assays, we observed Borrelia in all mouse skin and capsule fecal swabs tested, although we could not culture the spirochetes. These results update our previous analysis by revealing that spirochetes can also be visualized in tick excrement. Furthermore, the results emphasize that borrelial contamination by defecation is a possibility, and that caution should be exercised by researchers investigating pathogen/host/vector interactions. The biological significance of the presence of non-culturable Borrelia in tick feces during engorgement is unclear. |
Saliva, salivary gland, and hemolymph collection from Ixodes scapularis ticks
Patton TG , Dietrich G , Brandt K , Dolan MC , Piesman J , Gilmore RD Jr . J Vis Exp 2012 (60) Ticks are found worldwide and afflict humans with many tick-borne illnesses. Ticks are vectors for pathogens that cause Lyme disease and tick-borne relapsing fever (Borrelia spp.), Rocky Mountain Spotted fever (Rickettsia rickettsii), ehrlichiosis (Ehrlichia chaffeensis and E. equi), anaplasmosis (Anaplasma phagocytophilum), encephalitis (tick-borne encephalitis virus), babesiosis (Babesia spp.), Colorado tick fever (Coltivirus), and tularemia (Francisella tularensis) (1-8). To be properly transmitted into the host these infectious agents differentially regulate gene expression, interact with tick proteins, and migrate through the tick (3,9-13). For example, the Lyme disease agent, Borrelia burgdorferi, adapts through differential gene expression to the feast and famine stages of the tick's enzootic cycle (14,15). Furthermore, as an Ixodes tick consumes a bloodmeal Borrelia replicate and migrate from the midgut into the hemocoel, where they travel to the salivary glands and are transmitted into the host with the expelled saliva (9,16-19). As a tick feeds the host typically responds with a strong hemostatic and innate immune response (11,13,20-22). Despite these host responses, I. scapularis can feed for several days because tick saliva contains proteins that are immunomodulatory, lytic agents, anticoagulants, and fibrinolysins to aid the tick feeding (3,11,20,21,23). The immunomodulatory activities possessed by tick saliva or salivary gland extract (SGE) facilitate transmission, proliferation, and dissemination of numerous tick-borne pathogens (3,20,24-27). To further understand how tick-borne infectious agents cause disease it is essential to dissect actively feeding ticks and collect tick saliva. This video protocol demonstrates dissection techniques for the collection of hemolymph and the removal of salivary glands from actively feeding I. scapularis nymphs after 48 and 72 hours post mouse placement. We also demonstrate saliva collection from an adult female I. scapularis tick. |
Analysis of Borrelia burgdorferi surface proteins as determinants in establishing host cell interactions
Schmit VL , Patton TG , Gilmore RD Jr . Front Microbiol 2011 2 141 Borrelia burgdorferi infection causes Lyme borreliosis in humans, a condition which can involve a systemic spread of the organism to colonize various tissues and organs. If the infection is left untreated by antimicrobials, it can lead to manifestations including, arthritis, carditis, and/or neurological problems. Identification and characterization of B. burgdorferi outer membrane proteins that facilitate cellular attachment and invasion to establish infection continue to be investigated. In this study, we sought to further define putative cell binding properties of surface-exposed B. burgdorferi proteins by observing whether cellular adherence could be blocked by antibodies. B. burgdorferi mixed separately with monoclonal antibodies (mAbs) against outer surface protein (Osp) A, OspC, decorin-binding protein (Dbp) A, BBA64, and RevA antigens were incubated with human umbilical vein endothelial cells (HUVEC) and human neuroglial cells (H4). B. burgdorferi treated with anti-OspA, -DbpA, and -BBA64 mAbs showed a significant decrease in cellular association compared to controls, whereas B. burgdorferi treated with anti-OspC and anti-RevA showed no reduction in cellular attachment. Additionally, temporal transcriptional analyses revealed upregulated expression of bba64, ospA, and dbpA during coincubation with cells. Together, the data provide evidence that OspA, DbpA, and BBA64 function in host cell adherence and infection mechanisms. |
Functional analysis of the Borrelia burgdorferi bba64 gene product in murine infection via tick infestation.
Patton TG , Dietrich G , Dolan MC , Piesman J , Carroll JA , Gilmore RD Jr . PLoS One 2011 6 (5) e19536 Borrelia burgdorferi, the causative agent of Lyme borreliosis, is transmitted to humans from the bite of Ixodes spp. ticks. During the borrelial tick-to-mammal life cycle, B. burgdorferi must adapt to many environmental changes by regulating several genes, including bba64. Our laboratory recently demonstrated that the bba64 gene product is necessary for mouse infectivity when B. burgdorferi is transmitted by an infected tick bite, but not via needle inoculation. In this study we investigated the phenotypic properties of a bba64 mutant strain, including 1) replication during tick engorgement, 2) migration into the nymphal salivary glands, 3) host transmission, and 4) susceptibility to the MyD88-dependent innate immune response. Results revealed that the bba64 mutant's attenuated infectivity by tick bite was not due to a growth defect inside an actively feeding nymphal tick, or failure to invade the salivary glands. These findings suggested there was either a lack of spirochete transmission to the host dermis or increased susceptibility to the host's innate immune response. Further experiments showed the bba64 mutant was not culturable from mouse skin taken at the nymphal bite site and was unable to establish infection in MyD88-deficient mice via tick infestation. Collectively, the results of this study indicate that BBA64 functions at the salivary gland-to-host delivery interface of vector transmission and is not involved in resistance to MyD88-mediated innate immunity. |
Detection of Borrelia burgdorferi DNA in tick feces provides evidence for organism shedding during vector feeding.
Patton TG , Dietrich G , Gilmore RD . Vector Borne Zoonotic Dis 2010 11 (3) 197-200 Borrelia burgdorferi, the bacterium that causes Lyme disease, is transmitted to a susceptible host by Ixodes spp. tick bites. However, there is uncertainty whether B. burgdorferi are shed from ticks by the fecal route. In this study, B. burgdorferi-infected ticks were fed on mice while confined to a certain area of the skin by a capsule. During and after feeding, tick feces were collected and placed in Barbour-Stoenner-Kelley (BSK)-II media for cultivation and in sterile water for polymerase chain reaction (PCR) analysis. Although none of the tested samples were culture positive for B. burgdorferi, all but one of the fecal DNA samples from infected ticks were PCR positive. These results indicated that B. burgdorferi were shed from feeding ticks during defecation and suggest that the spirochetes did not remain viable once exposed to the outside environment. This finding has important ramifications for investigators interpreting B. burgdorferi-specific PCR results when conducting tick transmission experiments. |
The bba64 gene of Borrelia burgdorferi, the Lyme disease agent, is critical for mammalian infection via tick bite transmission
Gilmore RD Jr , Howison RR , Dietrich G , Patton TG , Clifton DR , Carroll JA . Proc Natl Acad Sci U S A 2010 107 (16) 7515-20 The spirochetal agent of Lyme disease, Borrelia burgdorferi, is transmitted by bites of Ixodes ticks to mammalian reservoir hosts and humans. The mechanism(s) by which the organism is trafficked from vector to host is poorly understood. In this study, we demonstrate that a B. burgdorferi mutant strain deficient in the synthesis of the bba64 gene product was incapable of infecting mice via tick bite even though the mutant was (i) infectious in mice when introduced by needle inoculation, (ii) acquired by larval ticks feeding on infected mice, and (iii) able to persist through tick molting stages. This finding of a B. burgdorferi gene required for pathogen transfer and/or survival from the tick to the susceptible host represents an important breakthrough toward understanding transmission mechanisms involved for the Lyme disease agent. |
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