Invasion and Metastasis Suppression by Anti-Neonatal Nav1.5 Antibodies in Breast Cancer.

BACKGROUND: Detectable neonatal Nav1.5 (nNav1.5) expression in tumour breast tissue positive for lymph node metastasis and triple-negative subtype serves as a valid tumour-associated antigen to target and prevent breast cancer invasion and metastasis. Therapeutic antibodies against tumour antigens have become the predominant class of new drugs in cancer therapy because of their fewer adverse effects and high specificity. OBJECTIVE: This study was designed to investigate the therapeutic and anti-metastatic potential of the two newly obtained anti-nNav1.5 antibodies, polyclonal anti-nNav1.5 (pAb-nNav1.5) and monoclonal anti-nNav1.5 (mAb-nNav1.5), on breast cancer invasion and metastasis. METHODS: MDA-MB-231 and 4T1 cells were used as in vitro models to study the effect of pAb-nNav1.5 (59.2 µg/ml) and mAb-nNav1.5 (10 µg/ml) (24 hours treatment) on cell invasion. 4T1-induced mammary tumours in BALB/c female mice were used as an in vivo model to study the effect of a single dose of intravenous pAb-nNav1.5 (1 mg/ml) and mAb-nNav1.5 (1 mg/ml) on the occurrence of metastasis. Real-time PCR and immunofluorescence staining were conducted to assess the effect of antibody treatment on nNav1.5 mRNA and protein expression, respectively. The animals' body weight, organs, lesions, and tumour mass were also measured and compared. RESULTS: pAb-nNav1.5 and mAb-nNav1.5 treatments effectively suppressed the invasion of MDA-MB-231 and 4T1 cells in the 3D spheroid invasion assay. Both antibodies significantly reduced nNav1.5 gene and protein expression in these cell lines. Treatment with pAb-nNav1.5 and mAb-nNav1.5 successfully reduced mammary tumour tissue size and mass and prevented lesions in vital organs of the mammary tumour animal model whilst maintaining the animal's healthy weight. mRNA expression of nNav1.5 in mammary tumour tissues was only reduced by mAb-nNav1.5. CONCLUSION: Overall, this work verifies the uniqueness of targeting nNav1.5 in breast cancer invasion and metastasis prevention, but more importantly, humanised versions of mAb-nNav1.5 may be valuable passive immunotherapeutic agents to target nNav1.5 in breast cancer.

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.

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.

Generation of a T cell receptor (TCR)-like single domain antibody (sDAb) against a Mycobacterium Tuberculosis (Mtb) heat shock protein (HSP) 16kDa antigen presented by Human Leukocyte Antigen (HLA)-A*02.

The discovery of heat shock protein 16 kDa antigen protein has deepen the understanding of latent tuberculosis since it was found to be primarily expressed by Mycobacterium tuberculosis during latent phase leading to the rapid optimization and development in terms of diagnosis and therapeutics. Recently, T cell receptor-like antibody has been explored extensively targeting various diseases due to its dual functionality (T cell receptor and antibody). In this study, a TCR-like domain antibody (A2/Ab) with the binding capacity to Mtb heat shock protein (HSP) 16 kDa antigen presented by major histocompatible complex (MHC) HLA-A*02 was successfully generated via biopanning against human domain antibody library. The generated antibody (A2/Ab) exhibited strong functionality and binding capacity against the target assuring the findings of this study to be beneficial for the development of latent tuberculosis diagnosis and immunotherapeutics in future.

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–Guérin (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 (IgG), IgG1 and IgG2a] 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 IgG and IgG1 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 NS4B 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 NS4B 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 NS4B mimotope on the development of a multi-epitope diagnostic tool. These results are important for further immunogenicity studies.

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 NS4B 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 NS4B 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 NS4B mimotope on the development of a multi-epitope diagnostic tool. These results are important for further immunogenicity studies.

Histopathological Study of the Lungs of Mice Receiving Human Secretory IgA and Challenged with Mycobacterium tuberculosis

Background: Humoral and cellular immune responses are associated with protection against extracellular and intracellular pathogens, respectively. In the present study, we evaluated the effect of receiving human secretory immunoglobulin A (hsIgA) on the histopathology of the lungs of mice challenged with virulent Mycobacterium tuberculosis. Methods: The hsIgA was purified from human colostrum and administered to Balb/c mice by the intranasal route prior to infection with M. tuberculosis or in a pre-incubated formulation with mycobacteria, with the principal aim to study its effect on qualitative pulmonary histopathology. Results: The intranasal administration of hsIgA and the pre-incubation of mycobacteria with this preparation was associated with the presence of organised granulomas with signs of immune activation and histological features related to efficient disease control. This effect was highly evident during the late stage of infection (60 days), as demonstrated by numerous organised granulomas with numerous activated macrophages in the lungs of treated mice. Conclusion: The administration of hsIgA to mice before intratracheal infection with M. tuberculosis or the pre-incubation of the bacteria with the antibody formulation induced the formation of well-organised granulomas and inflammatory lesions in lungs compared with non-treated animals which correlates with the protective effect already demonstrated by these antibody formulations.

Aplicación de una biblioteca de anticuerpos lineales humanos frente al polisacárido capsular de Neisseria meningitidis serogrupo B / Application of a human linear antibody library against the capsular polysaccharide from Neisseria meningitidis serogroup B

Neisseria meningitidis serogrupo B produce aún morbimortalidad significativa. Su polisacárido capsular muestra similitud estructural con proteínas humanas y pobre inmunogenicidad, obstaculizando así el desarrollo de vacunas y anticuerpos monoclonales (AcM) y policlonales contra esta bacteria. Recientemente se han creado bibliotecas artificiales de anticuerpos humanos expresados en bacteriófagos que reconocen específicamente a moléculas diana existentes, con la ventaja sobre los AcM convencionales por su rápida obtención, sin utilización de animales de laboratorio, lo que emerge como alternativa atractiva para la producción de AcM contra antígenos peculiares o complejos. Se realizó un trabajo de investigación básica, utilizando una biblioteca de fagos filamentosos que expresan constitutivamente regiones variables de anticuerpos humanos, que se enfrentó al polisacárido capsular de N. meningitidis serogrupo B. Los resultados que se obtuvieron mediante ELISA policlonal sugieren la existencia de anticuerpos humanos expresados en fagos que lo reconocen(AU)

Neisseria meningitidis serogroup B still produces a significant morbidity and mortality. Bacterial capsular polysaccharide in serogroup B shows structural homologies with human proteins and poor immunogenicity which make difficult the development of vaccines and polyclonal and monoclonal antibodies (MAb) against it. Artificial libraries of human antibodies via the expression and selection of them in bacteriophages have become known. Those antibodies are used as specific recognizing molecules capable to join to almost any existing target, with advantages over conventional MAb due to its faster obtainment without needing animal immunization, emerging as an attractive alternative for the production of MAb against complex or particular antigens. This was a basic experimental piece of work, using a phage library that expresses variable regions of human immunoglobulins to identify ligands with the capacity to recognize N. meningitidis serogroup B polysaccharide. Polyclonal ELISA screening suggests the existence of human antibodies expressed in phages which recognized the antigen of interest(AU)

The use of Streptomyces for immunization against mycobacterial infections.

Tuberculosis is one of the leading causes of mortality produced by an infectious agent. Different strategies including bioinformatics are currently being tested to identify and improve vaccines against tuberculosis. Comparative genome analysis between Streptomyces coelicolor and Mycobacterium tuberculosis suggest that both descend from a common Actinomycete ancestor. In this work, we suggest the use of Streptomyces as a live vector and explore the capacity of Streptomyces immunization to induce a protective response against mycobacterial infection. First, we compared the theoretical proteomes of S. coelicolor A3(2) with those of M. tuberculosis H37Rv and Mycobacterium bovis AF2122/97. This study showed a high similarity at the level of individual genes sequences with both bacteria sharing several membrane proteins. Then, we administered Streptomyces intraperitoneally to mice and determined its distribution by histopathology and culture; we did not find systemic dissemination. After administration of Streptomyces through different routes, we identified the most immunogenic, inducing strong humoral response, as denoted by the high serum antibody titers against this organism with cross reactivity to mycobacterial antigens. Finally, we evaluated the level of protection elicited by the inoculation of Streptomyces in Balb/c mice challenged with BCG. In these animals, lung bacillary loads were significantly lower than the control non-sensitized group.. These observations, along with Streptomyces' potential for expressing foreign proteins, suggest that Streptomyces could be an advantageous vector in the design of new tuberculosis vaccines.

The Importance of Animal Models in Tuberculosis Vaccine Development

Research, development, and production of vaccines are still highly dependent on the use of animal models in the various evaluation steps. Despite this fact, there are strong interests and ongoing efforts to reduce the use of animals in vaccine development. Tuberculosis vaccine development is one important example of the complexities involved in the use of animal models for the production of new vaccines. This review summarises some of the general aspects related with the use of animals in vaccine research and production, as well as achievements and challenges towards the rational use of animals, particularly in the case of tuberculosis vaccine development.

Identification of Dengue-specific B-Cell Epitopes by Phage-display Random Peptide Library

Background: Dengue is the most important human viral disease transmitted by arthropod vectors. The availability of random peptide libraries (RPL) displayed on phage has provided a powerful tool for selecting sequences that mimic epitopes from microorganisms that are useful for diagnostic and vaccine development purposes. In this paper, we describe peptides that resemble the antigenic structure of B-cell epitopes of dengue virus identified from a phage-peptide library using human sera containing polyclonal antibodies against dengue virus. Materials and Methods: Eighteen phage clones were isolated from the phage-display peptide library, J404, by affinity selection using human antisera against dengue virus type 3. These clones were tested for reactivity by ELISA with a panel of hyperimmune ascitic fluids (HAFs) containing antibodies either against all four dengue serotypes, West Nile virus (WNV) or Eastern equine encephalitis virus (EEEV) with control ascitic fluid (NAF) used as a negative control. Results: Eight clones were recognized by HAFs against the four dengue serotypes, of which four significantly inhibited binding of anti-dengue antibodies to the virus. Two peptides with similar sequences to regions of NS3 and NS4B non-structural dengue virus proteins were identified. Conclusion: Our results suggest that these peptides could be used for the development of diagnostic tools for the detection of dengue virus infection and for a potential vaccine against this pathogen.

Immunization of mice with a Mycobacterium tuberculosis genomic expression library results in lower bacterial load in lungs after challenge with BCG.

Tuberculosis is a serious infectious disease in many developing countries. The lack of an effective vaccine for preventing this disease has stimulated the search for new vaccine candidates against Mycobacterium tuberculosis. In the present work, the construction of a genomic expression library of M. tuberculosis in a eukaryotic expression vector was carried out. Immunization of Balb/c mice with a plasmid DNA pool from this library (containing 8360 clones) induced a significant IgG antibody response. Immunized mice were challenged by intratracheal route with 10(5) cfu of non-pathogenic Mycobacterium bovis BCG and were sacrificed 21 days post-challenge. Mice immunized with the genomic expression library showed a significant reduction of viable bacteria in lungs and less pulmonary tissue damage. Granulomas were not observed and the lungs had a more discrete perivascular inflammatory cell infiltrate compared to control mice. Results suggest that the genomic expression library contains genes encoding proteins that are protective against M. tuberculosis infection.

Respuesta humoral específica en ratones Balb/c inoculados con una librería genómica de expresión de Trypanosoma cruzi / Specific humoral response in Balb/c mice inoculated with a genome library of expression of Trypanosoma cruzi

A genomic expression library of Trypanosoma cruzi (T. cruzi) was made using plasmid pcDNA3 as a vector, with which male mice from the Balb/c isogenic line were intramuscullary inoculated. It was used a positive control group that was administered soluble antigens of T. cruzi. Other 2 groups received genomic and plasmid DNA, respectively. One group was not immunized. Weekly blood samples were obtained from all the animals until the fourth week and 2 weeks after reimmunization to study the response of specific antibodies against the microorganism antigens by an indirect immunoenzymatic assay (ELISA). It was observed a significant increase of specific antibodies in the animals reimmunized with 50 micrograms of the library, as well as in the group immunized with soluble antigens of T. cruzi.