Improved cellular immune response elicited by a ubiquitin-fused DNA vaccine against Mycobacterium tuberculosis.
ABSTRACT This study evaluated the immune response elicited by a ubiquitin (Ub)-fused MPT64 DNA vaccine against Mycobacterium tuberculosis. BALB/c mice were vaccinated with plasmid DNA encoding MPT64 protein, Ub-fused MPT64 DNA vaccine (UbGR-MPT64), and negative DNA vaccines, respectively. MPT64 DNA vaccine immunization induced a Thl-polarized immune response. The production of Thl-type cytokine (interferon-gamma [IFN-γ]) and proliferative T cell responses were enhanced significantly in mice immunized with UbGR-MPT64 fusion DNA vaccine, compared with nonfusion DNA vaccine. Moreover, this fusion DNA vaccine also resulted in an increased relative ratio of IgG2a to IgGl and the cytotoxicity of T cells. IFN-γ intracellular staining of splenocytes indicated that UbGR-mpt64 fusion DNA vaccine activated CD4+ and CD8+ T cells, particularly CD8+ T cells. Thus, this study demonstrated that the UbGR-MPT64 fusion DNA vaccine inoculation could improve antigen-specific cellular immune responses, which is helpful for protection against TB.
SourceAvailable from: Ernesto T.A. Marques[Show abstract] [Hide abstract]
ABSTRACT: We have previously demonstrated that a DNA vaccine encoding HIV-p55gag in association with the lysosomal associated membrane protein-1 (LAMP-1) elicited a greater Gag-specific immune response, in comparison to a DNA encoding the native gag. In vitro studies have also demonstrated that LAMP/Gag was highly expressed and was present in MHCII containing compartments in transfected cells. In this study, the mechanisms involved in these processes and the relative contributions of the increased expression and altered traffic for the enhanced immune response were addressed. Cells transfected with plasmid DNA constructs containing p55gag attached to truncated sequences of LAMP-1 showed that the increased expression of gag mRNA required p55gag in frame with at least 741 bp of the LAMP-1 luminal domain. LAMP luminal domain also showed to be essential for Gag traffic through lysosomes and, in this case, the whole sequence was required. Further analysis of the trafficking pathway of the intact LAMP/Gag chimera demonstrated that it was secreted, at least in part, associated with exosome-like vesicles. Immunization of mice with LAMP/gag chimeric plasmids demonstrated that high expression level alone can induce a substantial transient antibody response, but targeting of the antigen to the endolysosomal/secretory pathways was required for establishment of cellular and memory response. The intact LAMP/gag construct induced polyfunctional CD4+ T cell response, which presence at the time of immunization was required for CD8+ T cell priming. LAMP-mediated targeting to endolysosomal/secretory pathway is an important new mechanistic element in LAMP-mediated enhanced immunity with applications to the development of novel anti-HIV vaccines and to general vaccinology field.PLoS ONE 06/2014; 9(6):e99887. DOI:10.1371/journal.pone.0099887 · 3.53 Impact Factor
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ABSTRACT: DNA vaccination consists of administering an antigen-coding nucleotide sequence. In order to improve the efficacy of DNA vaccines, electroporation is one of the most commonly used methods to enhance DNA uptake. Here, we discuss additional immunological effects of electroporation that are key aspects for inducing immunity in response to DNA vaccines.OncoImmunology 04/2014; 3:e28540. DOI:10.4161/onci.28540 · 6.28 Impact Factor
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ABSTRACT: Mycobacterium tuberculosis is the major pathogen of tuberculosis (TB). With the growing problem of M. tuberculosis resistant to conventional antibiotics, especially multi-drug resistant tuberculosis (MDR-TB) and extensively-drug resistant tuberculosis (XDR-TB), the need for new TB drugs is now more prominent than ever. Among the promising candidates for anti-TB drugs, anti-mycobacterial peptides have a few advantages, such as low immunogenicity, selective affinity to prokaryotic negatively charged cell envelopes, and diverse modes of action. In this review, we summarize the recent progress in the anti-mycobacterial peptides, highlighting the sources, effectiveness and bactericidal mechanisms of these antimicrobial peptides. Most of the current anti-mycobacterial peptides are derived either from host immune cells, bacterial extraction, or mycobacteriophages. Besides trans-membrane pore formation, which is considered to be the common bactericidal mechanism, many of the anti-mycobacterial peptides have the second non-membrane targets within mycobacteria. Additionally, some antimicrobial peptides play critical roles in innate immunity. However, a few obstacles, such as short half-life in vivo and resistance to antimicrobial peptides, need overcoming before clinical applications. Nevertheless, the multiple functions of anti-mycobacterial peptides, especially direct killing of pathogens and immune-modulators in infectious and inflammatory conditions, indicate that they are promising candidates for future drug development. © 2015 S. Karger AG, Basel.Cellular Physiology and Biochemistry 01/2015; 35(2):452-466. DOI:10.1159/000369711 · 3.55 Impact Factor