Salmonella typhi Ty21a bacterial ghost vector augments HIV-1 gp140 DNA vaccine-induced peripheral and mucosal antibody responses via TLR4 pathway

Potent immune responses induced by a Salmonella ghost delivery system that expresses the recombinant Stx2eB, FedF, and FedA proteins of the Escherichia coli-producing F18 and Shiga toxin in a murine model and evaluation of its protective effect as a porcine vaccine candidate

“…We also assessed the immunogenicity elicited by a mixture formula of these ghosts in mice. Salmonella ghosts in genetically engineered inactive vaccine systems have received increased interest due to their adaptability as foreign antigen delivery systems (Wen et al 2012;. Each antigen protein was sub-cloned in the ghost plasmid pJHL184, where the E gene is regulated by convergent promoter elements .…”

“…The bacteria envelopes, where all of the cytoplasmic contents are expelled through the tunnel, are known as bacterial ghosts (BGs); these retain all of the native antigenic features of the surface components of the bacteria (Szostak et al 1996). In this context, BGs can be recognized and processed by dendritic cells (Kudela et al 2005), induce robust humoral and cellular immunity, and enhance protective efficacy Wen et al 2012;Chen et al 2014;Zhu et al 2015). In addition to these immuno-stimulatory properties of BGs, the capacity of BGs to be efficiently engulfed by antigen-presenting cells also provides their intrinsic adjuvant properties to the immunized host when BGs are utilized to deliver heterologous antigens (Ebensen et al 2004;Walcher et al 2004).…”

“…S. Typhimurium strain has been successfully prepared for delivering heterologous antigen proteins to induce raised immune responses against the antigens (Russmann et al 1998). Further, the BGs derived from Salmonella enterica were genetically constructed for use as a vaccine candidate or a vaccine delivery vector to minimize potential reactogenicity of a live attenuated Salmonella (Chaudhari et al 2012;Wen et al 2012). In the current study, to construct the ghost that produces these antigens, each gene was individually fused in-frame to the outer membrane protein A (ompA) signal peptide of a ghost plasmid cassette (pJHL184).…”

How can Improve DNA Vaccine Modalities as a Therapeutic Approach against HIV Infections?

“…Peripheral and intestinal mucosal anti-gp120 antibody responses in mice vaccinated with BGs-DNA vaccine were significantly higher than those in mice immunized with naked DNA vaccine. The enhancement of antibody responses was associated with BG-induced production of IL-10 through TLR4 pathway [26].…”

DNA Vaccines for the Induction of Immune Responses in Mucosal Tissues

“…The enhancement of antibody responses was associated with BGinduced production of IL-10 through the TLR-4 pathway. Ty21a BG-based delivery system was shown to enhance the ability of a DNA vaccine to elicit peripheral and mucosal antibody immune responses, presumably through the upregulation of the Th2 immune response via the TLR-4 and possibly TLR-5 pathways (Wen et al, 2012).…”