Immunostimulative Action of Trypanosoma brucei Phospholipase A2 Gene Containing CpG Motifs Confers Homologous Protection against Infection in Experimental Mice

Abstract

Aim: Interest in phospholipase A2 has continued to rise since its biotechnological potentials and involvement in the pathogenicity of Trypanosoma species were recognized, therefore this study was designed to investigate the vaccine potential of Trypanosoma brucei PLA2 gene containing cytosine phosphate guanine (CpG) motifs against trypanosomiasis. Place and Duration of Study: Department of Biotechnology, NVRI, Vom; Department of Parasitology, NITR, Vom and University of Jos, Nigeria between June 2011 and April, 2012. Methodology: Bloodstream rat adapted strain of T. brucei was grown in rats and separated using DEAE cellulose chromatography. PCR amplification of phospholipase A2 like gene from Trypanosome brucei cDNA synthesized by RT-PCR using parasites’ RNA was done. Bioinformatics analyses of the gene sequence were done using Finch TV® programmes (GeoPiza) and Webgene programmes. Immunization of mice with DNA, immune sera and spleen extract were also carried out. Results: A 1344 sequence obtained revealed CpG islands between positions 1 and 904. Immunization of mice with the PLA2 DNA and in combination with partially purified parasite PLA2 enzyme suppressed parasitemia as well as improved hematological indices and so enhanced survival of immunized mice post-infection. Passive immunization with immune sera and spleen extract showed suppressed parasitemia throughout the experimental period and delayed mortality to a greater extent compared to the DNA immunization. Conclusion: The findings signify that DNA immunization confers protection on mice revealing the vaccine potential of PLA2 like gene from Trypanosoma brucei.