Executive Summary : | Small ruminant lentiviruses (SRLVs) distributed worldwide and cause maedi visna and caprine arthritis encephalitis diseases in small ruminants. Lentiviruses are associated with important diseases like AIDS, equine infectious anaemia, bovine immunodeficiency disease, feline immunodeficiency, etc. and mostly related with the immune system. These lentiviral diseases increase the susceptibility of the animals to other diseases due to their immunosuppressive effect. Similarly, SRLVs infects monocyte/macrophage lineage cells and expected to alter the immune response of the affected animals. Pathologically, SRLVs causes interstitial pneumonia, encephalitis, arthritis and mastitis, and causes economic losses to the farmers due to decreased production and mortality. Currently, no treatment and effective vaccine are available for the SRLVs, due to its rapid evolution, genetic diversity, viral latency, persistence in host cells and antigenic diversity. But disease can be controlled effective by timely diagnosis and culling of the affected animals. Currently SRLVs are divided into five categories viz. A, B, C, D and E but from India no information is available regarding their occurrence. Although reports of the SRLVs prevalence from the different regions of the India were reported but their characterization has not been done. Diagnosis of SRLV infections is possible by PCR and serological assays, and if the spreaders in a flock are identified early, then they can be separated from the healthy animals and losses can be minimised/prevented. Mostly, the ELISA assays developed by using single proteins/antigens of single SRLV strain but it is reported that immunoassays using multiple proteins/antigens from different strains are comparatively more sensitive. So, keeping these points in consideration, the present proposal is designed to characterize the SRLV strains prevalent in India and develop a multiple antigenic construct (MAC) based diagnostic for its early diagnosis. For this, the samples will be collected from different regions of the country and screened for SRLVs by PCR. Further, positive samples will be characterized by amplifying the gag, gag-pol and pol gene regions, sequencing and phylogenetic analysis. For development of MAC based diagnostic assay, the sequences of SRLVs will be extracting for the selected antigens by using the computational biology and bioinformatic tools. These MACs will be expressed by using recombinant DNA technology to develop the indirect ELISA for the SRLV diagnosis. The assays developed will be able to diagnose the different disease conditions of SRLVs arising from varied strains by a single test. Serological diagnostics for the SRLVs are available in the foreign countries but in India no one is screening the flock for these diseases due to very high cost of these testing kits and the chances of the SRLV strain variation in Indian population. |