Objective: To determine the effects of toll-like receptor 2 (TLR-2) agonist, Pam3CSK4, on cellular and humoral immune response against recombinant Mycobacterium bovis bacilli Calmette-Guérin (rBCG) expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum. Methods: Six groups of mice (n=6 per group) received intraperitoneal phosphate buffered saline T80 (PBS-T80), BCG or rBCG in the presence or absence of Pam3CSK4. Enzymelinked immunosorbent assay was carried out to measure serum total IgG, IgG1, IgG2a, and IgG2b production. Spleens were also harvested and splenocytes were co-cultured with rBCG antigen for in vitro determination of IL-4 and IFN-γ via enzyme-linked immunosorbent assay. Results: The production of total IgG and the isotype IgG1, IgG2a and IgG2b was significantly higher in rBCG-immunised mice than in the BCG and PBS-T80-immunised mice, and Pam3CSK4 further enhanced their productions. A similar pattern was also observed in IFN-γ production. Moreover, there was no significant difference in IL-4 production in all groups either in the presence or absence of Pam3CSK4. Conclusions: We present evidence of the adjuvant effects of TLR-2 agonist in enhancing the production of total IgG, IgG1, IgG2a, IgG2b, as well as IFN-γ in response to rBCG. However, the presence or absence of Pam3CSK4 had no effect on IL-4 production.
Universiti Sains Malaysia (USM) Research University (RU) Grants (No. 1001/PPSK/8011100)