Mouse IgG2b Isotype Control [APC/Cy5.5®]

The adjuvant activity of Chenopodium quinoa (quinoa) saponins on the humoral and cellular immune responses of mice subcutaneously immunized with ovalbumin (OVA) was evaluated. Two quinoa saponin fractions were obtained, FQ70 and FQ90, and 10 saponins were determined by UPLC/Q-TOF-MS. Mice were immunized subcutaneously with OVA alone or adjuvanted with Quit A (adjuvant control), FQ70, or FQ90. FQ70 and FQ90 significantly enhanced the amount of anti-OVA-specific antibodies in serum (IgG, IgG1, and IgG2b) in immunized mice. The adjuvant effect of FQ70 was significantly greater than that of FQ90. However, delayed type hypersensitivity responses were higher in mice immunized with OVA adjuvanted with FQ90 than mice treated with FQ70. Concanavalin A (Con A)-, lipopolysaccharide-, and OVA-stimulated splenocyte proliferation were measured, and FQ90 significantly enhanced the Con A-induced splenocyte proliferation. The results suggested that the two quinoa saponin fractions enhanced significantly the production of humoral and cellular immune responses to OVA in mice.

Objective: To determine the role of toll-like receptor 4 (TLR-4) in eliciting cellular and humoral immune responses against recombinant Mycobacterium bovis bacille Cahnette-Guerin (rBCG) 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 rBCG intraperitoneally, in the presence or absence of a TLR-4 inhibitor; TAK-242. Enzyme-linked immunosorbent assay was carried out for serum total IgG, IgG1, IgG2a and IgG2b determination. Spleens were also harvested and splenocytes cultured for determination of intracellular cytokines; IL-4 and IFN- gamma via enzyme-linked immunosorbent assay. Results: The production of total IgG. and the subclasses IgG1, IgG2a and IgG2b was significantly higher in rBCG-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 IgG2a was highest, followed by IgG2b, then IgG1. The production of both IL-4 and IFN- gamma was also highest in the rBCG immunised groups. These significant rises were inhibited in the presence of TAK-242. Conclusions: We present evidence of the role of TLR-4 in the increased production of total IgG, IgG1, IgG2a and IgG2b, as well as IL-4 and IFN- gamma in response to our rBCG construct.