No abstract

The effector function of natural killer, lymphokine-activated killer cells and T lymphocytes is commonly evaluated by radioactive chromium-release cytotoxicity assays. In addition to this indirect method, fluorescence assays have been described for the assessment of in vitro cell-mediated cytotoxicity. In the present study, target cells were stained with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE), which is a stable integrated fluorescent probe that allows target and effector cells to be distinguished from one another. Staining of target THP-1 cells with 8 µM CFSE revealed high and stable loading of fluorescence and no effect of the viability of cells. After 4 h of in vitro co-culture between γδ T cells and CFSE-labeled infected or uninfected THP-1 cells, staining with propidium iodide (PI) was performed to distinguish between vital and dead cells. During sample acquisition, target cells were gated on the CFSE positivity and examined for cell death based on the uptake of PI. CFSE and PI double positive cells were recognized as the dead target cells. The percentage of cytotoxicity in the CFSE-gated cell population was calculated by subtracting the value obtained for non-specific PI-positive target cells, which was measured in a control group that did not contain effector cells. The present study describes a simple and convenient assay that is based on the direct quantitative and qualitative analysis of cell damage at a single cell level utilizing a two-color flow cytometric assay. In conclusion, the flow cytometric-based assay described in the current study is a simple, sensitive and reliable tool to determine the cytolytic activity of γδ T lymphocytes against mycobacteria. Therefore, the present study may provide valuable information concerning the methods employed to investigate the function of γδ T cells and potentially other lymphocyte subsets.

Salmonella evades host immune response via the expression of a variety of pathogenic factors. The 'pRST98' plasmid of Salmonella enterica serotype Typhi (S. Typhi) is involved in conferring the multidrug‑resistance and virulence of S. typhi. However, its specific effect on host‑cell function has remained elusive. Dendritic cells (DCs) are key regulators of immune responses. The present study therefore aimed to investigate whether pRST98 may target DCs involved in mediating the adaptive immune response. In vivo experiments with Salmonella enterica serotype Typhimurium χ3337 and χ3337/pRST98 revealed that pRST98 may influence multiple important functions of murine DCs, including maturation, survival and cytokine production. In addition, pRST98 markedly contributed to decreasing T‑cell activation. These data suggested that by targeting the aforementioned functions of DCs, pRST98 may partially overturn the adaptive immune defense mechanisms of the host, which are required for elimination of this pathogen from infected tissues. This may contribute to the evasion of host adaptive immune responses by S. Typhi and therefore provide a target for the prevention and treatment of typhoid fever.

PURPOSE:To investigate the hepatotoxicity and nephrotoxicity of 3-Bromopyruvate (3BP) in mice. hours later, the blood were used for the determination of hepatic damage serum biomarkers. Livers were stored in 4 % formalin solution for the later detection. METHODS: RESULTS:3BP at the dose of 8mg/kg had a good effect on inhibiting tumor growth in nude mice and did not damage liver and kidney tissues. Kunming mice experiment showed 3BP at the dose of 16mg/kg did damage to liver tissues. CONCLUSION:3-Bromopyruvate at the dose of suppressing tumor growth did not exhibit hepatotoxicity and nephrotoxicity in nude mice, and the effect on liver was confirmed in Kunming mice.