Peripheral blood T cell TNF-α and IFN-γ production stimulated by low molecular peptide of Mycobacterium tuberculosis heat-resistant antigen for differential diagnosis between pulmonary tuberculosis and latent tuberculosis infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of low molecular peptide of Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg-10k) on the production of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in peripheral blood T cells and test the feasibility of differential diagnosis between pulmonary tuberculosis (PTB) and latent tuberculosis infection (LTBI) by assessing the number of Mtb-HAg-10k-stimulated IFN-γ-producing T cells.</p><p><b>METHODS</b>Peripheral blood mononuclear cells (PBMCs) were separated from the peripheral blood of 10 healthy adults, 6 individuals with LTBI and 13 patients with PTB. The PBMCs were cultured in the presence of Mtb-HAg-10k obtained by ultrafiltration centrifugation, with Mtb-HAg and phytohaemagglutinin (PHA) as the controls. The proportions of TNF-α- and IFN-γ-producing cells in the T cell subsets were detected by flow cytometry (FCM), and the number of IFN-γ-producing cells from patients with PTB and LTBI was detected with ELISPOT.</p><p><b>RESULTS</b>Flow cytometry showed that Mtb-HAg-10k exposure resulted in a significantly higher proportion of TNF-α-producing γδT cells than that of IFN-γ-producing γδT cells in the PBMCs (P<0.01). Compared with the PBMCs exposed to PHA, the PBMCs exposed to Mtb-HAg-10k exhibited a significantly greater proportion of γδT cells that produced both TNF-α and IFN-γ (P<0.01) but a significantly lower proportion of αβT cells producing both TNF-α and IFN-γ (P<0.01). Mtb-HAg-10k exposure of the PBMCs caused a significant reduction in the number of IFN-γ-producing cells as compared with Mtb-HAg and PHA treatments (P<0.01), and this reduction was more obvious in PBMCs from patients with PTB than in those from individuals with LTBI (P<0.01).</p><p><b>CONCLUSION</b>Mtb-HAg-10k can markedly induce γδT cells in the PBMCs to produce TNF-α and IFN-γ, and detection of the number of IFN-γ-producing cells in the PBMCs following Mtb-HAg-10k stimulation helps in the differential diagnosis between pulmonary tuberculosis and latent tuberculosis infection.</p>

Frequency Distribution Features of Innate-like Lymphocytes in Peripheral Blood of Normal Adults / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the frequency distribution features of innate-like lymphocytes (iNKT cells, γΔT cells and B1 cells) in peripheral blood of normal adults.</p><p><b>METHODS</b>The flow cytometry with 6 fluorescence staining was used to detect the percentages of iNKT lymphocytes, γΔT lymphocytes, B1 lymphocytes and adaptive T lymphocyte, B2 lymphocytes in peripheral blood lymphocytes of 50 normal adults. The difference and correlation between these lymphocyte subsets were analyzed by statistical software.</p><p><b>RESULTS</b>The percentage of iNKT cells in peripheral blood of 50 normal adults was 0.18% (0.01%-2.01%), the percentage of γΔT cells was 4.90% (1.45%-20.14%), the percentage of B1 lymphocytes was 1.62% (0.20%-3.77%), the percentage of adaptive T cells was 63.52% (33.20%-83.22%), the percentage of B2 cells was 6.64% (3.07%-13.80%). B1 and B2 were two subsets of B lymphocyte, the percentage of B2 in B lymphocyte was 81.43% (57.90%-94.12%) and more than that of B1 lymphocyte; the percentage of B1 lymphocytes was 17.28% (5.28%-41.13%). In T lymphocyte group the percentage of iNKT cell was 0.32% (0.01%-3.6%), the percentages of γΔT cells and adaptive T cells were 7.55% (3.04%-27.66%) and 91.98% (72.22%-96.86%) respectively. Spearman correlation analysis was used to analyze the correlation between the percentages of several lymphocyte subsets. There was a positive correlation between iNK T cells and γΔT cells, γΔT cells and adaptive T cells, B1 cells and B2 cells (r=0.39, P=0.0056; r=0.6028, P<0.0001; r=0.4791, P=0.0004). It was also found that the percentage of iNKT cells in female peripheral blood lymphocytes was 0.29% (0.06%-2.01%), and significantly higher than that in male peripheral blood lymphocytes 0.12% (0.01%-1.37%) (P<0.05).</p><p><b>CONCLUSION</b>The percentages of γΔT cells, B1 cells and iNKT cells in peripheral blood lymphocytes of normal adults are significantly lower than that of adaptive lymphocytes, and their contents in peripheral blood decrease in turn. There are no sex differences in the percentages of these lymphocyte subsets except iNKT cells.</p>

Construction and eukaryotic expression of recombinant porcine single-chain interleukin-12 / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone the p40 and p35 subunit cDNA of porcine IL-12(pIL-12) and construct the fusion gene of recombinant porcine single-chain interleukin-12 (pscIL-12).</p><p><b>METHODS</b>The total RNAs were extracted from porcine peripheral blood mononuclear cells (PBMCs) and porcine splenic lymphocytes for cloning pIL-12 p35 and p40 cDNA by RT-PCR. A hydrophobic polypeptide linker (Gly4Ser)3 was used for splicing two different gene fragments (pIL-12) p40+linker+p35 (pscIL-12) by recombinant PCR to construct pscIL-12 fusion gene. The pscIL-12 fusion gene was then inserted into pcDNA3.1(+) eukaryotic expression plasmid, and the resulted pcDNA3.1(+)-pscIL-12 was transfected into CHO-K1 cells via lipofectin. The expression of pscIL-12 mRNA in the transfected cells was identified by RT-PCR.</p><p><b>RESULTS</b>The sequence of the cloned porcine IL-12 p40 and p35 cDNA and the constructed pscIL-12 fusion gene were verified by PCR, restriction enzyme digestion and sequencing. The mRNA of pscIL-12 fusion gene was detected in the transfected CHO-K1 cells by RT-PCR.</p><p><b>CONCLUSION</b>The constructed pcDNA3.1(+)-pscIL-12 eukaryotic expression plasmid allows expression of pscIL-12 in CHO-K1 cells, thus facilitating further study of the biological activity and adjuvant effect of pscIL-12 fusion protein.</p>

Molecular mechanism of anti-apoptotic action of survivin in NCI-H446 lung cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate cell apoptosis induced by survivin ASODN and clarify the precise mechanism of anti-apoptotic action of survivin.</p><p><b>METHODS</b>Cells of lung cancer cell line NCI-H446 were treated with survivin ASODN at different concentrations. The changes of survivin mRNA and protein expression were assessed by RT-PCR and Western blot assay. The apoptosis index (AI) and proliferation index (PI) were determined by flow cytometry (FCM). After 500 mmol/L survivin ASODN treatment, cells were stained with Rh123 to detect changes of mitochondrial membrane potential (deltapsim) by FCM. The concentration of cytoplasmic cytochrome c (cyt-c) was continuously determined by ELISA. Relative activities of caspase-9 and caspase-3 were assessed by colorimetric assay. The expression of caspase-8 protein was measured by Western blot assay. The apoptotic rates of lung cancer cells induced by survivin ASODN with or without mitochondrial permeability transition pole (MPTP) inhibitor CsA treatment were assessed by FCM.</p><p><b>RESULTS</b>Down-regulated survivin mRNA was shown to be in dose-dependent and time-dependent manners. Its maximal effect was achieved at a concentration of 500 nmol/L for 72 h, at which mRNA was down-regulated by 62.7%, the expression of survivin protein in NCI-H446 cells was also obviously decreased. After treatment with survivin ASODN at concentration of 500 mmol/L for 72 h, AI was 48.35%, higher than that of control, lipofectin, NSODN, survivin ASODN 100 mmol/L and 300 mmol/L groups (3.75%, 3.41%, 4.69%, 19.85% and 34.39%, respectively). PI was 24.38%, lower than that of control, lipofectin, NSODN, survivin ASODN100 and 300 mmol/L groups (75.74%, 73.12%, 71.76%, 51.03% and 38.94%, respectively). Deltapsim was decreased in 9.54% of NCI-H446 cells treated with survivin ASODN for 3 h and 97.06% for 24 h. Following it, release of cyt-c from mitochondria to cytosol and activation of caspase-9 and caspase-3 increased significantly. The above mentioned indicators changed with a time-dependent and time diversity relationship. In the presence of CsA, the apoptotic rate of lung cancer cells induced by survivin ASODN was decreased significantly. No up-regrulation and activation in caspase-8 protein was observed.</p><p><b>CONCLUSION</b>Survivin inhibits apoptosis via regulation of mitochondrial-dependent pathway. survivin ASODN can not only induce apoptosis but also inhibit cell proliferation through blocking the expression of survivin mRNA and protein.</p>