A Probiotic Adjuvant Lactobacillus rhamnosus Enhances Specific Immune Responses after Ocular Mucosal Immunization with Chlamydial Polymorphic Membrane Protein C

Abstract

Recent advances in the development of chlamydia vaccines, using live-attenuated or ultraviolet light-inactivated chlamydia, are paving the way for new possibilities to oppose the societal challenges posed by chlamydia-related diseases, such as blinding trachoma. An effective subunit vaccine would mitigate the risks associated with the use of a whole-cell vaccine. Our rationale for the design of an efficient subunit vaccine against Chlamydia trachomatis (Ct) is based on the membrane proteins involved in the initial Ct-host cell contact and on the route of immunization that mimics the natural infection process (i.e., via the ocular mucosa). The first aim of our study was to characterize the specific conjunctival and vaginal immune responses following eye drop immunization in BALB/c mice, using the N-terminal portion of the Ct serovar E polymorphic membrane protein C (N-PmpC) as the subunit vaccine antigen. Second, we aimed to examine the adjuvant properties of the probiotic Lactobacillus rhamnosus (LB) when formulated with N-PmpC. N-PmpC applied alone stimulated the production of N-PmpC- and Ct serovar B-specific antibodies in serum, tears and vaginal washes, whereas the combination with LB significantly enhanced these responses. The N-PmpC/LB combination initiated a T cell response characterized by an elevated percentage of CD25+ T cells and CD8+ effector T cells, enhanced CD4+ T-helper 1 skewing, and increased regulatory T cell responses. Together, these results show that eye drop vaccination with combined use of N-PmpC and a live probiotic LB stimulates specific cellular and humoral immune responses, not only locally in the conjunctiva but also in the vaginal mucosa, which could be a promising approach in Ct vaccine development.

Assessment of Probiotic Properties of Lactobacillus salivarius Isolated From Chickens as Feed Additives

“…In addition, we also found that Lactobacillus salivarius group exhibited an enhanced immune response after immunization compared to control group in chickens without cy treatment. This is consistent with previous results that Lactobacillus can be used as immune adjuvant to enhance antigen-specific immune responses (30,31).…”

Comparison of the nine polymorphic membrane proteins of Chlamydia trachomatis for their ability to induce protective immune responses in mice against a C. muridarum challenge

“…In addition to working with C. muridarum , Karunakaran et al [47] also immunized mice with a polyvalent vaccine formulated with PmpEFGH from C. trachomatis serovar D and three MOMPs from serovars D, J and F. The mice were challenged transcervically and, as determined by the number of C. trachomatis serovar D IFU recovered, animals vaccinated with the combination of the four Pmps and the three MOMPs, were better protected than those vaccinated with either the Pmps, or the three MOMPs alone. Interestingly, Inic-Kanada et al reported that PmpC of C. trachomatis serovar B elicited partial protection in guinea pigs against an ocular challenge with C. caviae [48, 49]. …”

“…The sequence identity of PmpC for the E, F and Da serovars is 98–100% and therefore, inclusion of this antigen in a human vaccine could have a major impact on the prevalence of chlamydial infections. In support of the possibility of cross-serovar protection induced by PmpC, Inic-Kanada et al [48] have recently shown that mice vaccinated in the ocular mucosa with PmpC from C. trachomatis serovar E developed humoral and cell mediated immune responses that cross-reacted with serovar B.…”

New Progress Regarding the Use of Lactic Acid Bacteria as Live Delivery Vectors, Treatment of Diseases and Induction of Immune Responses in Different Host Species Focusing on Lactobacillus Species

“…Development of immunity by Lactobacillus strains could associated with lymphoid tissues that regulate the immune response of their hosts for example Lactobacillus helveticus R389, Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus HN017 [97,[166][167][168] have been reported to have the ability to improve the immune system of their host. The mechanism of this improvement is thought to be caused by the consequence of the Lactobacillus strains because of the: total serum protein, globulin, interferon-gamma, prostaglandin E production, albumin, tumor necrosis factor, interleukin-1 (IL-1), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), and lymphocytes proliferation.…”