Abstract

Complement lectins are pathogen recognition receptors (PRRs) that bind to pathogen associated molecular patterns (PAMPs) of various microbes. The circulating serum levels and functional genetic variants of four such innate immune recognition elements, namely the human mannose-binding lectin (MBL), ficolin-2 (FCN2), collectin 11 (CL-K1), mannose-binding associated serine protease-2 (MASP2) were studied in intracellular (visceral leishmaniasis) and extracellular (urinary schistosomiasis) parasitic diseases. In extracellular Schistosoma haematobium infection, MBL, MASP2, and collectin-11 (CL-K1) and their functional variants were associated with relative protection. In intra-cellular Leishmania donovani infection, MBL, ficolin-2 and their functional variants were observed to be a susceptible host factor. IL-6 was observed to regulate the lectin expression during distinct parasitic infections. In conclusion, this dissertation provides probable evidence on the differential role of lectins in intra and extracellular infections.