Objective: To determine the effects of toll-like receptor 2(TLR-2) agonist, Pam3 CSK4, on cellular and humoral immune response against recombinant Mycobacterium bovis bacille Calmette-Guérin(rBCG) expressing the ...Objective: To determine the effects of toll-like receptor 2(TLR-2) agonist, Pam3 CSK4, on cellular and humoral immune response against recombinant Mycobacterium bovis bacille 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 Pam3 CSK4. Enzymelinked immunosorbent assay was carried out to measure serum total IgG, IgG1, IgG2 a, and Ig G2 b 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, IgG2 a and IgG2 b was significantly higher in rBCG-immunised mice than in the BCG and PBS-T80-immunised mice, and Pam3 CSK4 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 Pam3 CSK4.Conclusions: We present evidence of the adjuvant effects of TLR-2 agonist in enhancing the production of total IgG, IgG1, IgG2 a, IgG2 b, as well as IFN-γ in response to rBCG. However, the presence or absence of Pam3 CSK4 had no effect on IL-4 production.展开更多
Background: Although BCG is the most widely administered vaccine in the world, there have never been as many cases of TB as there are now. Globally, more than 8.8 million people developed active TB and 1.4 million—ma...Background: Although BCG is the most widely administered vaccine in the world, there have never been as many cases of TB as there are now. Globally, more than 8.8 million people developed active TB and 1.4 million—many of them—died in 2010. It is estimated that half of pulmonary TB cases arise from latent Mtb infection, making the study of latency and reactivation of utmost importance. Methods: Widely administered BCG vaccines and a gene modified recombinant BCG (rBCG) strain, AERAS-422, were used as models to investigate the growth promoting function of resuscitation-promoting factors (Rpfs) in different bacilli culture phases. Different supernatant fractions were prepared by ultrafiltration, and the promoting function of each fraction containing secreted Rpf(s) was evaluated by growth curve monitoring and colony counting on 7H10 agar plates. Results: The promoting effect of culture supernatants was mainly associated with the high molecular weight fraction (>30 kDa), which stimulated bacterial growth, but did not extend the exponential phase of stimulated culture. Anti-RpfB antibody showed significant growth restriction of the tested cultures. When comparing rBCG cultures containing 7H9 medium, the 10 - 30 kDa fraction, or the >30 kDa fraction, only the >30 kDa fraction was displayed with down-regulation of the secretion of RpfC, D and E. In colony counting tests, the plates containing the >30 kDa fraction had total countable colony numbers 2 to 3 fold higher than the plates with the 10 - 30 kDa fraction, and colonies appeared one to two weeks earlier than on the regular plates. The potential applications of the prepared supernatant fractions containing RpfA and RpfB are discussed, which may include accelerating diagnosis of Mtb infection and future TB vaccine development.展开更多
基金supported by the Universiti Sains Malaysia(USM)Research University(RU)Grants(No.1001/PPSK/8011100)
文摘Objective: To determine the effects of toll-like receptor 2(TLR-2) agonist, Pam3 CSK4, on cellular and humoral immune response against recombinant Mycobacterium bovis bacille 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 Pam3 CSK4. Enzymelinked immunosorbent assay was carried out to measure serum total IgG, IgG1, IgG2 a, and Ig G2 b 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, IgG2 a and IgG2 b was significantly higher in rBCG-immunised mice than in the BCG and PBS-T80-immunised mice, and Pam3 CSK4 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 Pam3 CSK4.Conclusions: We present evidence of the adjuvant effects of TLR-2 agonist in enhancing the production of total IgG, IgG1, IgG2 a, IgG2 b, as well as IFN-γ in response to rBCG. However, the presence or absence of Pam3 CSK4 had no effect on IL-4 production.
文摘Background: Although BCG is the most widely administered vaccine in the world, there have never been as many cases of TB as there are now. Globally, more than 8.8 million people developed active TB and 1.4 million—many of them—died in 2010. It is estimated that half of pulmonary TB cases arise from latent Mtb infection, making the study of latency and reactivation of utmost importance. Methods: Widely administered BCG vaccines and a gene modified recombinant BCG (rBCG) strain, AERAS-422, were used as models to investigate the growth promoting function of resuscitation-promoting factors (Rpfs) in different bacilli culture phases. Different supernatant fractions were prepared by ultrafiltration, and the promoting function of each fraction containing secreted Rpf(s) was evaluated by growth curve monitoring and colony counting on 7H10 agar plates. Results: The promoting effect of culture supernatants was mainly associated with the high molecular weight fraction (>30 kDa), which stimulated bacterial growth, but did not extend the exponential phase of stimulated culture. Anti-RpfB antibody showed significant growth restriction of the tested cultures. When comparing rBCG cultures containing 7H9 medium, the 10 - 30 kDa fraction, or the >30 kDa fraction, only the >30 kDa fraction was displayed with down-regulation of the secretion of RpfC, D and E. In colony counting tests, the plates containing the >30 kDa fraction had total countable colony numbers 2 to 3 fold higher than the plates with the 10 - 30 kDa fraction, and colonies appeared one to two weeks earlier than on the regular plates. The potential applications of the prepared supernatant fractions containing RpfA and RpfB are discussed, which may include accelerating diagnosis of Mtb infection and future TB vaccine development.
