Identification of a HSP14-3-3 in Setaria cervi and its cross-reactivity with W bancrofti-infected human sera.

AIM: Identification of a 29 kDa heat stress protein in filarial parasite Setaria cervi and evaluation of its diagnostic potential against lymphatic filariasis.

METHODS AND

RESULTS

The Heat shock proteins (HSPs) were induced in filarial parasite S cervi by incubated at 42°C for 2 hours. The 10% SDS-PAGE of cytosolic extract showed several over-expressed bands. The MALDI-LC/MS analysis of 29 kDa band showed 100% similarity with Bm14-3-3 like protein 2. Multiple sequence alignment of Bm14-3-3 like protein 2 sequence with W bancrofti, Caenorhabditis elegans; Loa loa and Homo sapiens showed 100%, 86%, 83% and 78%, sequence similarity respectively. The antigenic efficacy of Sc14-3-3 protein was evaluated with different filarial sera using ELISA which showed cross-reactivity in order to Endemic Normal (EN) < Microfilaraemic (MF) < Chronic(CH) with IgG1 and EN < CH < MF in IgG4 ELISA. IgG1- and IgG4-specific immunoblotting with CH and MF sera further explicated its specific antigenic cross-reactivity.

CONCLUSION

A 29 kDa heat shock protein of S cervi was identified as 14-3-3 protein having 100% homology to human filarial parasite B malayi. It showed strong reactivity with IgG1 and IgG4 subclass antibodies of W bancrofti-infected human sera suggesting that 14-3-3 protein could be used as a vaccine/ diagnostic marker.