Molecular characterization and bioinformatic analysis of SGU protein in Anopheles culicifacies as target for transmission blocking activity.

In tropical countries, malaria transmission is the major health issue. To eradicate malaria, health communities depend on the control measure that affects economy and environment of the countries. To overcome these burdens, there is a great need to develop vaccine against malaria, but there is no vaccine to control malaria effectively. Transmission blocking vaccine (TBV) is the best alternative approach to control malaria, which inhibits the malaria transmission. Mosquito-based TBVs, blocks the transmission of Plasmodium developmental stages in mosquito. There are some potential candidate antigens for mosquito-based TBV, e.g., AgCPB1, AnAPN1, AgFREP1, etc. AcSGU is one of the most potential candidates for TBVs. AcSGU protein is glycol-anchored protein in Anopheles culicifacies which is highly expressed after blood feeding. In the present study acsgu gene was amplified from genomic DNA, sequenced (GenBank id: MN402758) and characterised. The sequence of acsgu (gene and protein) was analysed by different immuno-informatics tools to confirm its potentiality as a candidate antigen. The target protein was cloned, isolated and immunised for immunogenic response analysis. The acsgu gene is single exonic which encodes for AcSGU protein with single functional MBF2 domain. It is conserved in most of the Anopheles species. Bioinformatics analysis confirmed the stability and immunogenic nature of the protein. Protein-Protein interaction revealed effective interaction of AcSGU with Pf47 and TLR4 molecules. AcSGU protein was expressed in E. coli BL21 (DE3) by using expression vector pLATE51. The immunogenic response in AcSGU protein was remarkable in the rabbit. This study confirmed that AcSGU protein is the potential candidate for transmission blocking vaccine to generate anti-midgut immunity against plasmodium. It can be used as a candidate for the development of multistage targeting vaccines against malaria.