Chikungunya and Dengue virus biology

Two major arthropod borne viruses that have emerged in the recent past in India are the Dengue virus and Chikungunya virus. Dengue viral infections causing Dengue Fever/Dengue Hemorrhagic Fever/Dengue Shock Syndrome has become a major public health problem in our country. The disease has become endemic in many states and cause regular out-breaks of the disease, especially during the seasons of high mosquito breeding. Similarly, many parts of the country witnessed an explosive out-break of chikungunya in 2006 and 2007. The unprecedented severity of this out-break was thought to be associated with genetic changes that has occurred in the virus in the recent past. Our primary interest is characterization of the Dengue and Chikungunya viral genotypes circulating in South India, Kerala in particular; and documentation of specific mutations that may affect viral virulence. We also look into the development of targeted antiviral development against these viruses, taking the envelop protein and NS3 protease as primary targets for chikungunya and dengue virus, respectively. In silico docking of natural product libraries and screening of herbal plant extracts and marine compounds are carried out to identify potential viral inhibitors.

Cytokine Biology of domestic ducks

Waterfowls, especially domestic ducks (Anas platyrhynchos), are important species in the context of poultry husbandry. Their role as carriers of potent zoonotic pathogens such as avian influenza, and as surrogate animal models of human disease, (eg. chronic hepatitis B) makes this species important in the context of public health also. Basic information on immunology and immunological mediators is essential for understanding disease pathogenesis in ducks and for developing their control strategies. We try to understand basic immunology of domestic ducks with particular reference to cytokine and chemokine genes. Current studies focus on basic characterization of RANTES (Regulated upon activation; Normal T-cell expressed and secreted), MIP- β (macrophage inflammatory protein-β) and MCP-like (monocyte chemoattractant protein) chemokines of ducks and their role in the immunopathology of duck hepatitis B and duck plague virus infections. Use of the duck hepatitis B model system is also being explored for bio-prospecting medicinal plants for novel anti-hepatitis B drugs.

Study of anti-microbial peptides of avian origin

Natural peptides with antimicrobial activity obtained from various sources are being extensively investigated for developing novel therapeutics against infections. Among these antimicrobial peptides (AMPs), members of the β-defensin family are isolated from a wide variety of species. They are present predominantly on epithelial and mucosal surfaces and show broad spectrum antimicrobial and immunomodulatory properties. Anatin-2 is a novel avian β-defensin homologue identified from domestic ducks in our laboratory. As for other β-defensins, it shows antibacterial activity in preliminary studies. Our aim is to generate recombinant peptides with improved potency and antibacterial spectrum by site-directed mutagenesis of this molecule. Such novel antimicrobial peptides will help in overcoming the emerging problem of antibiotic resistance and will be useful as topical agents in treating chronic infections of the skin and mucosal epithelium.