Human angiostrongyliasis results from accidental infection with Angiostrongylus, an intra-arterial nematode. Angiostrongylus cantonensis infections result in eosinophilic meningitis, and A. costaricensis infections cause eosinophilic enteritis. Immunological methodologies are critical to the diagnosis of both infections, since these parasites cannot be isolated from fecal matter and are rarely found in cerebrospinal fluid samples. A. costaricensis and A. cantonensis share common antigenic epitopes which elicit antibodies that recognize proteins present in either species. Detection of antibodies to a 31-kDa A. cantonensis protein present in crude adult worm extracts is a sensitive and specific method for immunodiagnosis of cerebral angiostrongyliasis. The objective of the present work was to isolate and characterize the 31-kDa proteins using soluble protein extracts derived from adult female worms using both one- (1DE) and two-dimensional (2DE) gel electrophoresis. Separated proteins were blotted onto nitrocellulose and probed using sera from infected and non-infected controls. The 31-kDa band present in 1DE gels and the 4 spots identified in 2DE gels were excised and analyzed by electrospray ionization mass spectrometry. Using the highest scores obtained following Mascot analysis, amino acid sequences were obtained that matched four unique proteins: tropomyosin, the 14-3-3 phosphoserine-binding protein, a protein containing a nascent polypeptide-associated complex domain, and the putative epsilon subunit of coatomer protein complex isoform 2. Oxidative cleavage of diols using sodium m-periodate demonstrated that carbohydrate moieties are essential for the antigenicity of all four spots of the 31-kDa antigen. In this article we describe the identification of the 31-kDa antigen, and provide DNA sequencing of the targets. In conclusion, these data suggest that reactivity to the 31-kDa proteins may represent antibody recognition of more than one protein, and recombinant protein-based assays for cerebral angiostrongyliasis diagnosis may require eukaryotic expression systems to maintain antigenicity.

Tick-borne encephalitis virus (TBEV) is a neurotropic, positive-sense RNA virus of the genus Flavivirus (family Flaviviridae) which can cause a variety of clinical manifestations in humans. Previously the severity and outcome of dengue fever and hepatitis C (diseases caused by viruses from the family Flaviviridae) were associated with the rs4804803 single nucleotide polymorphism (SNP) located in the promoter region of the human CD209 gene. This gene encodes dendritic cell-specific ICAM3-grabbing nonintegrin (DC-SIGN), a C-type lectin pathogen-recognition receptor expressed on the surface of dendritic cells and some types of macrophages. In the current study, a possible association between two SNPs in the promoter region of the CD209 gene (rs4804803 and rs2287886) and predisposition to severe forms of TBEV-induced disease was investigated. The genotypic, allelic and haplotypic frequencies of these SNPs were analyzed in 136 non-immunized Russian patients with different clinical manifestations of tick-borne encephalitis (TBE) and in a control group. An increase in the frequency of the rs2287886 SNP AA homozygotes and the A allele was detected among patients with severe central nervous system disease compared with the group of patients with meningitis (P=0.003 and 0.019), or a combined group of patients with mild forms (fever and meningitis) (P=0.003 and 0.026), or the control group (P=0.007 and 0.035). Thus, our results suggest that the CD209 gene promoter region rs2287886 SNP is associated with predisposition to severe forms of TBE in the Russian population.

West Nile virus (WNV), a category B pathogen endemic in parts of Africa, Asia and Europe, emerged in North America in 1999, and spread rapidly across the continental U.S. Outcomes of infection with WNV range from asymptomatic to severe neuroinvasive disease manifested as encephalitis, paralysis, and/or death. Neuroinvasive WNV disease occurs in less than one percent of cases, and although host genetic factors are thought to influence risk for symptomatic disease, the identity of these factors remains largely unknown. We tested 360 common haplotype tagging and/or functional SNPs in 86 genes that encode key regulators of immune function in 753 individuals infected with WNV including: 422 symptomatic WNV cases and 331 cases with asymptomatic infections. After applying a Bonferroni correction for multiple tests and controlling for population stratification, SNPs in IRF3 (OR 0.54, p = 0.035) and MX1, (OR 0.19, p = 0.014) were associated with symptomatic WNV infection and a single SNP in OAS1 (OR 9.79, p = 0.003) was associated with increased risk for West Nile encephalitis and paralysis (WNE/P). Together, these results suggest that genetic variation in the interferon response pathway is associated with both risk for symptomatic WNV infection and WNV disease progression.