Purification, Characterization and Vaccine Potential of Trypanosoma brucei brucei Glycosyl Phosphatidyl Inositol Specific Phospholipase C.

ABSTRACT

Aims: To investigate possible use of Glycosylphosphatidylinositol-specific phospholipase C (GPIPLC) as a target protein for the development of vaccine against Trypanosoma brucei brucei infection was investigated. Study Design: GPI-PLC from T. brucei brucei was purified, characterized and the protein was used as antigen in raising antibody against the parasite Place and Duration Department of Biochemistry, Ahmadu Bello University Zaria-Nigeria, between September 2011 and October 2012 Methodology: GPI-PLC was isolated from T. brucei brucei and purified by ammonium sulphate precipitation, gel filtration and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDSPAGE). The GPI-PLC was further used to raise antisera in rabbits, which was subsequently used to immunize rats for 14 and 21 days pre-infection to investigate the possible use of T. b. brucei GPI-PLC as target protein in vaccine production against T. b. brucei infection. Results: An overall yield of 48.76% and purification fold of 10.86 were recorded after gel filtration. The result from SDS-PAGE showed the enzyme to be a 39.585 kDa protein with optimum temperature, optimum pH and activation energy to be 35°C, 8.1 and 19.494 kJ/ mol respectively. The Vmax and Km values were 6.67 × 10-3 μmol/hr and 2.67 × 10-3 μM respectively when 212.5 μg of enzyme was used in the reaction mixture. Immunization with anti GPI-PLC for 14 and 21 days pre-infection significantly lowered the Packed Cell Volume (PCV). Result for the time course of parasitemia following infection with 7.9 x 105 Cells/ml showed a decrease in parasitemia level, thus leading to lowering of mortality rates in Groups immunized with GPI-PLC for 14 and 21 days pre-infection by 20% and 40% respectively relative to Group infected but not treated. Conclusion: These results suggest that GPI-PLC as a target protein significantly reduced the progression of the T. b. brucei infection.