CRX-527 as a candidate adjuvant in a recombinant BCG-based malaria vaccine

Objective:To investigate the role of CRX-527,a Toll-like receptor 4 agonist,as the possible adjuvant for recombinant Mycobacterium bovis Bacillus Calmette-Guerin expressing merozoite surface protein 1C(BCG-MSP-1C).Methods:The mice were immunized with BCG and BCG-MSP-1C in the presence and absence of CRX-527.The untreated mice(injected with PBS-T80 only)were the negative control.The ability of CRX-527 to enhance IgG and its subclasses,as well as IL-4 and IFN-γproduction in the serum and spleen supernatant was evaluated using ELISA.Results:Mice immunized with BCG-MSP-1C exhibited the highest production of IgGs,IL-4 and IFN-γafter third immunization.In addition,CRX-527 further promoted the production of total IgG and IgG subclasses as well as IFN-γand IL-4 in the serum and splenocytes of immunized mice.Conclusions:CRX-527 has the potential as an adjuvant candidate for the candidate vaccines.Further study is needed to verify appropriate dosage for immunization and its efficacy.

Pam3CSK4 enhances adaptive immune responses to recombinant Mycobacterium bovis bacille Calmette-Guérin expressing Plasmodium falciparum C-terminus merozoite surface protein-1

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.

Role of toll-like receptor 4 in eliciting adaptive immune responses against recombinant BCG expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum

Objective: To determine the role of toll-like receptor 4(TLR-4) in eliciting cellular and humoral immune responses against recombinant Mycobacterium bovis bacille Calmette-Guérin(rB CG) expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum. Methods: Six groups of mice(n=6 per group) were injected with phosphate buffered saline T80, BCG or r BCG intraperitoneally, in the presence or absence of a TLR-4 inhibitor; TAK-242. Enzyme-linked immunosorbent assay was carried out for serum total IgG, IgG 1, Ig G2 a and Ig G2 b determination. Spleens were also harvested and splenocytes cultured for determination of intracellular cytokines; IL-4 and IFN-毭 via enzyme-linked immunosorbent assay. Results: The production of total Ig G, and the subclasses Ig G1, Ig G2 a and Ig G2 b was significantly higher in rB CG-immunised mice than BCG and phosphate buffered saline immunised mice in the absence of TAK-242. A significant rise in total IgG occurred with more booster immunisations. The level of IgG 2 a was highest, followed by IgG 2 b, then IgG 1. The production of both IL-4 and IFN-were inhibited in t毭 was also highest in the rB CG immunised groups. These significant riseshe presence of TAK-242. Conclusions: We present evidence of the role of TLR-4 in the increased production of total IgG, IgG 1, IgG 2 a and IgG 2 b, as well as IL-4 and IFN-毭 in response to our rB CG construct.

Role of toll like-receptor 2 in inflammatory activity of macrophage infected with a recombinant BCG expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum

Objective: To investigate the role of toll-like receptor 2(TLR2) in inflammatory activity of macrophage infected with the recombinant Mycobacterium bovis bacillus Calmette-Guerin(rBCG). Methods: Mouse macrophage cell line J774 A.1 was infected with Mycobacterium bovis bacillus Calmette-Guerin(BCG) and rBCG cultures for 48 h in the presence or absence of 10 μg/mL of TLR2 inhibitor. Untreated macrophages were used as a negative control while lipopolysaccharide-stimulated macrophages were used as a positive control. The ability of the macrophage to engulf the BCG and rBCG in the absence or presence of TLR2 inhibitor was assessed using a phagocytic assay, while the production of inflammatory cytokines and nitric oxide by the infected macrophages was evaluated using ELISA and Griess reagent method, while the expression of the inducible nitric oxide synthase was determined using Western blot analysis. Results: The results showed that blocking TLR2 function reduced the phagocytic activity, nitric oxide production and proinflammatory cytokine secretion such as TNF-α, IL-1β and IL-12 p40 as well as inducible nitric oxide synthase expression in the infected macrophages. These data showed the importance of TLR2 in the activation of macrophages following BCG and r BCG infections. Conclusions: Through exploring the immunological mechanism which underlies the protection conferred by the candidate vaccine, this study will improve our understanding of the vaccine candidate's mechanism to protect the host from malaria infection.

Immunomodulatory effects and structure-activity relationship of botanical pentacyclic triterpenes:A review

Botanical pentacyclic triterpenes possessed a broad range of pharmacological activities such as antioxidant,anti-tumor,anti-microbial and anti-inflammatory activities.It is believed that the mechanisms involved in these bioactivities are due to the modulation of immune system.Recently,the pharmacological validation on immunomodulatory of pentacyclic triterpenes derived from higher plants is very limited and several existence review papers related for this group of compound have not been focused for this activity.In this review,we have highlighted several studies on immunomodulatory potential of botanical pentacyclic triterpenes isolated from wide array of different species of medicinal plants and herbs based on various preclinical in vitro and animal models.This review also attempts to discuss on bioactivities of compouns related with their structure-activity relationship.Hence,the evaluation of pentacyclic triterpenes offers a great opportunity to discover adjuvants and novel therapeutic agents that presented beneficial immunomodulatory properties.