T-h-2 immunity and CD3⁺CD45RB^low-activated T cells in mice immunized with recombinant bacillus Calmette–Guérin expressing HIV-1 principal neutralizing determinant epitope

Abstract

The genetic engineering of Mycobacterium bovis-bacillus Calmette-Guérin to express foreign epitopes is an attractive strategy in the field of epitope vaccines. We constructed an 'epitope-trap vector' with Mycobacterium tuberculosis chaperonin-10 as a carrier antigen and used it to express the HIV-1 principal neutralizing determinant epitope. We also identified a new chaperonin-10 promoter that was hyperexpressive compared with the heat shock protein-65 promoter. Splenocytes from recombinant bacillus Calmette-Guérin-immunized mice showed enhanced lymphocyte proliferation and interleukin-4 (but not interferon-gamma) secretion. The recombinant bacillus Calmette-Guérin-immunized group also exhibited mild delayed-type hypersensitivity reaction and a high frequency of CD3+CD45RBlow-activated T cells, together with high titer of antiprincipal neutralizing determinant immunoglobulin G antibodies. Thus, this epitope delivery system induced strong epitope-specific T-h-2 polarization.

Mycobacterium tuberculosis groEpromoter controls the expression of the bicistronicgroESL1operon and shows differential regulation under stress conditions

“…A comparative analysis of the groE promoter with the groEL2 promoter showed that, the former was much more active than the latter both in E. coli and in M. smegmatis (Fig. 1) in accordance with our previous observation (Aravindhan et al , 2006). It is of interest to note that the groE promoter contains one CIRCE element, while the groEL2 promoter contains two such sequences and might be under tight repression (Stewart et al , 2002a, b).…”

BpOmpW Antigen Stimulates the Necessary Protective T-Cell Responses Against Melioidosis

“…T-cell activation also leads to CD45RB regulation, an essential marker that determines the fate of T cells from naive to effector/memory cells. The generation of effector T cells that will undergo development to memory cells is an essential correlate of protection in determining the efficacy of vaccines ( 33 , 34 ). All effector subsets evaluated, i.e., effector CD4 and effector CD8, were increased in the BpOmpW-immunized group, indicating that the antigen produces a robust effector recall response that is likely to lead to a memory response, a hallmark of an efficacious vaccine.…”

BpOmpW Antigen Stimulates the Necessary Immune Correlates of Protection Against Melioidosis

“…T cell activation also leads to CD45RB regulation, an essential marker that determines the fate of T cells from naïve to memory cells. The generation of effector T cells that will undergo development to memory cells is an essential correlate of protection in determining the efficacy of vaccines (Robinson & Amara, 2005;Aravindhan et al, 2006). All effector subsets evaluated, i.e., effector CD4 and effectors CD8 were increased in BpOmpW immunized group, indicating that the antigen produces a robust effector recall response that is likely to lead to a memory response, a hallmark of an efficacious vaccine.…”

“…All rights reserved. No reuse allowed without permission.undergo development to memory cells is an essential correlate of protection in determining the efficacy of vaccines(Robinson & Amara, 2005;Aravindhan et al, 2006). All effector subsets evaluated, i.e., effector CD4 and effectors CD8 were increased in BpOmpW immunized group, indicating that the antigen produces a robust effector recall response that is likely to lead to a memory response, a hallmark of an efficacious vaccine.The early immune responses to control melioidosis infection are predominantly mediated by IFN-g in both CD4 + and CD8 + T cells, and as recently reported in NK and DN cells(Kronsteiner et al, 2019; Rongard et al, 2020).…”