Brugia malayi Wolbachia hsp60 IgG antibody and isotype reactivity in different clinical groups infected or exposed to human bancroftian lymphatic filariasis.

Wolbachia, an endosymbiotic bacterium in filarial parasites, comes into contact with the host immune system upon parasite death. Here, we analyzed, total IgG and isotype antibody responses to Wolbachia hsp60 in individuals from an area endemic for Wuchereria bancrofti. Wolbachia derived hsp60 gene was cloned and the recombinant protein was used to determine the IgG and isotype reactivity by Western blotting and ELISA. All individuals from the endemic area generated antibody responses to Brugia malayi Wolbachia hsp60, which were elevated in the group with chronic pathology. Isotype analysis showed that, all clinical groups mounted IgG1-IgG4 responses with higher levels of B. malayi Wolbachia hsp60 specific IgG1 observed in the sera of patients with chronic pathology compared to microfilaraemics and endemic normals. These findings suggests that Wolbachia-derived hsp60 generates antibody responses in individuals infected or exposed to W. bancrofti and an elevated IgG and IgG1 reactivity is observed in people with filarial pathology.

Setaria digitata: identification and characterization of a hypodermally expressed SXP/RAL2 protein.

SXP-1, an immunodominant filarial protein identified from Wuchereria bancrofti from our centre and previously exploited for diagnosis of human lymphatic filariasis, has been shown to be well conserved across several filarial species. In the present study, we describe the identification of SXP protein from the cattle filarid Setaria digitata using antiserum raised against recombinant WbSXP-1, and were able to detect 34 and 66kDa proteins from the crude protein extracts of S. digitata. These reactive proteins were found to be sheath proteins localized to the hypodermal region of the parasite.