Protection against human papillomavirus type 16-induced tumors in C57BL/6 mice by mucosal vaccination with Lactococcus lactis NZ9000 expressing E6 oncoprotein

Oral immunization of mice with Lactococcus lactis expressing Shiga toxin truncate confers enhanced protection against Shiga toxins of Escherichia coli O157:H7 and Shigella dysenteriae

“…LL‐Stx2a1 elicited better mucosal and systemic immune responses in comparison with controls because of the exposure to gut‐associated lymphoid tissues as mentioned earlier . Previous findings have shown the oral efficacy of L. lactis to induce mucosal immune responses . Antibodies raised against LL‐Stx2a1 showed definite reactivity with E. coli O157 and S. dysenteriae native toxins in both ELISA and Western blot assays.…”

Twenty years of research on HPV vaccines based on genetically modified lactic acid bacteria: an overview on the gut-vagina axis

“…This was further supported by recent in vivo studies, where vaccination of mice challenged with a lethal dose of the tumor cell line TC-1 with recombinant L. lactis were associated with an effective antitumor protection against an E6-and E7-expressing tumor cells (i.e., TC-1) and a higher survival rate compared to control animals. Additionally, the outcomes showed robust therapeutic anti-cancer effects against recognized tumors in vivo [20,35]. Similarity, Li et al showed that intranasal immunization of mice with live L. lactis containing HPV-16 E7 oncoprotein can elicit a E7-specific protective and therapeutic immune response against TC-1 tumors [38].…”

“…Similarly, Mohseni et al and Taghinezhad-S et al found that oral immunization with recombinant L. lactis producing HPV-16 E6/E7 oncoproteins enhanced mucosal cellular immunity such as E6-and E7-specific IL-2-and IFN-γ-positive CD4 + and CD8 + T cell numbers in antigen-stimulated splenocytes, intestinal mucosal lymphocytes, and vaginal lymphocytes, suggesting that mucosal lymphocyte population include memory T cells which recognize E6/E7 antigens. Most important, their recombinant L. lactis strains induced significantly higher levels of immune response to MHCII (E6/7-specific CD4 + T helper) and MHCI (E6/7-specific CD8 + T cell) epitopes from recombinant E6/E7 [20,35]. These outcomes support the results of Lee et al, who observed that oral administration of L. casei harboring PgsA-E6 oncoprotein contributes to stimulation of E6-specific T cell responses in mesenteric lymph nodes (MLN), splenocytes, and vaginal samples [36].…”

Mucosal vaccines and technology

“…Although a commercial HPV vaccine is available, it does not confer protection to all HPV-related cancers [49]. Generally recognized as safe (GRAS) strains of Lactoccus lacti engineered to express the HPV-16 E6 oncoprotein generated humoral and cellular immune response in mice after oral administration, as well being shown to have an inhibitory effect on tumour growth [98]. There are, however, biosafety and environmental contamination concerns in using genetically modified bacteria [99].…”