Specific and cross-reactive immune response against Mycobacterium tuberculosis antigens in mice immunized with proteoliposomes from Mycobacterium bovis BCG

Objective: To characterize the immunogenicity and the induction of cross-reactive responses against Mycobacterium tuberculosis(M. tuberculosis) of a proteoliposome(PL)from Mycobacterium bovis Bacillus Calmette–Guerin(BCG) with and without alum hydroxide(AL) as adjuvant(PLBCG-AL and PLBCG, respectively) in BALB/c mice.Methods: BALB/c mice were inoculated with phosphate buffer solution, BCG, PLBCG and PLBCG-AL. The humoral immunogenicity was determined by ELISA [immunoglobulin G(Ig G), Ig G1 and Ig G2a] and the cellular immunogenicity was evaluated in vivo by delayed type hypersensitivity. The humoral cross-reactive response against M. tuberculosis was determined by Western blot.Results: Sera from animals immunized with PLBCG-AL and PLBCG showed significant increase in specific total Ig G and Ig G1 antibodies and the presence of cross-reactive antibodies against M. tuberculosis antigens, which were more intense with the use of alum as adjuvant. Mice immunized with PLBCG and PLBCG-AL also showed a specific cellular response in vivo.Conclusions: The cellular and humoral immunogenicity of PLBCG and the capacity to induce cross-reactive responses against M. tuberculosis is in agreement with the protective capacity previously demonstrated by this vaccine candidate and supports the continuation of its evaluation in further stages.

Recognition of a multiple antigen peptide containing sequence from mimotope of the dengue type 3 virus NS4B protein by human antibodies

Objective: To evaluate the recognition of NS4 B mimotope, as multiple antigen peptide(MAP), by dengue antibodies presents in serum samples from patients with different serotype infections. Methods: A MAP containing mimotope sequence was synthesized and used to evaluate the recognition of NS4 B mimotope as MAP by a panel of 66 human sera from dengue cases by an indirect ELISA assay. Results: The MAP differentiated between sera from dengue viruses infected patients and sera from healthy individuals and the best reactivity was shown by serum from dengue type 3 virus patients. The recognition was more intense with serum from patients with secondary infection. Conclusions: The findings suggest the potential use of NS4 B mimotope on the development of a multi-epitope diagnostic tool. These results are important for further immunogenicity studies.

Liposomes as immunological adjuvants and delivery systems in the development of tuberculosis vaccine:A review

Liposomes are phospholipid bilayer vesicles,which are biocompatible,biodegradable and nontoxic vehicles suitable for numerous drug and gene delivery applications.In this review,we discuss the prospect of using liposome technology in the development of a vaccine for tuberculosis.Tuberculosis remains an important health problem that requires the development of an effective vaccine,especially since the only approved vaccine for it continues to be the Bacille Calmette-Geurin(BCG)one developed 100 years ago.This review focuses on the different applications of liposomes toward achieving this goal.Numerous liposomal formulations showing prospect in the research stage and in clinical trials are discussed.