High-throughput identification and dendritic cell-based functional validation of MHC class I-restricted Mycobacterium tuberculosis epitopes

Novel epitopes identified from Tembusu virus NS3 protein induce cytotoxic T lymphocyte response

Since 2010, Tembusu virus (TMUV) has spread widely in China, causing huge economic losses to the poultry industry. Due to the infectious and zoonotic nature of flaviviruses, their potential threat to public health is of great concern. Cellular immune responses usually play a critical role in combating viral infections. To study the molecular basis of cell immunity induced by TMUV, 14 cytotoxic T lymphocyte (CTL) epitope peptides of TMUV antigen E, NS1 and NS3 were predicted by bioinformatics tools. Their abilities to induce cellular immune responses were determined by IFN-γ ELISpot assay, and 4 peptides were found to exhibit highly significant responses upon stimulation. In addition, the cytotoxic activity induced by the epitope peptides was assessed by lactate dehydrogenase (LDH) release assay. Finally, among these peptides, we identified two murine TMUV NS3-derived H-2d-restricted CTL epitopes in BALB/c mice, which could be used to further study of epitope vaccines against TMUV infection.

It Takes a Village: The Multifaceted Immune Response to Mycobacterium tuberculosis Infection and Vaccine-Induced Immunity

Despite co-evolving with humans for centuries and being intensely studied for decades, the immune correlates of protection against Mycobacterium tuberculosis (Mtb) have yet to be fully defined. This lapse in understanding is a major lag in the pipeline for evaluating and advancing efficacious vaccine candidates. While CD4+ T helper 1 (TH1) pro-inflammatory responses have a significant role in controlling Mtb infection, the historically narrow focus on this cell population may have eclipsed the characterization of other requisite arms of the immune system. Over the last decade, the tuberculosis (TB) research community has intentionally and intensely increased the breadth of investigation of other immune players. Here, we review mechanistic preclinical studies as well as clinical anecdotes that suggest the degree to which different cell types, such as NK cells, CD8+ T cells, γ δ T cells, and B cells, influence infection or disease prevention. Additionally, we categorically outline the observed role each major cell type plays in vaccine-induced immunity, including Mycobacterium bovis bacillus Calmette-Guérin (BCG). Novel vaccine candidates advancing through either the preclinical or clinical pipeline leverage different platforms (e.g., protein + adjuvant, vector-based, nucleic acid-based) to purposefully elicit complex immune responses, and we review those design rationales and results to date. The better we as a community understand the essential composition, magnitude, timing, and trafficking of immune responses against Mtb, the closer we are to reducing the severe disease burden and toll on human health inflicted by TB globally.

Novel epitopes identified from Mycobacterium tuberculosis antigen Rv2629induces cytotoxic T lymphocyte response

There is an urgent need for a more effective vaccine against tuberculosis (TB). Cytotoxic T lymphocytes (CTLs) play a critical role in combating Mycobacterium tuberculosis (M.tb). The identification of novel CTL epitopes is essential for the design of peptide-based vaccines. In this study, we predicted CTL epitope peptides of M.tb antigen Rv2629 restricted by HLA-A2, using bioinformatics methods. The affinity and stability of binding of these peptides with HLA-A2 molecules were detected by flow cytometry. Their ability to induce CTLs generation was determined in peripheral blood mononuclear cells (PBMCs) from healthy uninfected subjects, Latent tuberculosis infection (LTBI) subjects, and TB patients ex vivo. The cytotoxic activity induced by the epitope peptides was tested by lactate dehydrogenase (LDH) release assay. Finally, we found four novel CTL epitope peptides, Rv2629-p190-2L, Rv2629-p190-1Y2L, Rv2629-p274, and Rv2629-p315, which had high-affinity and stability of binding with T2 cells. Their ability of inducing CTLs was highest in PBMCs from TB patients (P < 0.05). In addition, these peptides could induce the CTLs to generate specific cytotoxic activity. They showed higher immunogenicity in TB patients and had the potential to become candidate vaccines for TB therapy.