Affect Of Mycobacterium Tuberculosis On RAW264.7 Cell And THP-1 Cells Cytokine Expression And Apoptosis

Tuberculosis is the first global disease which issued by World Health Organization. According to statistics, there are 8 million new cases each year and and up to two million deaths cases. In recent years, we have to face a new threat because of the appearance of drug-resistant stains of Mycobacterium tuberculosis and the expansion of human immunodeficiency disease. In order to diagnosis,treatment and prevention tuberculosis we still need to strengthen basic research and applied research for TB. In order to investigate the influence of transcription and expression of several major Cytokines for apoptosis, a THP-1 of macrophages and RAW264.7 of macrophages were established in vitro model.Infected cells with three different virulence Mycobacterium tuberculosis: high virulent tuberculosis H37 Rv,BCG and Mycobacterium bovis of deer, flow cytometry was used to detect macrophage apoptosis at six time points, Griess assay was used to detect secretion of NO, cck-8 was used to detect cell proliferation after infection, quantitative PCR was used to detect transcription level of cytokines TNF-α, IL-10,IL-6, and ELISA was used to detect the secretion of cell supernatants of three cytokines.The results show: each infected groups were significantly different(P<0.05)on apoptosis、NO secretion and proliferation. NO secretion of each infection group on the two cells showed an upward trend, and apoptosis and cell proliferation situation is more complicated. Each time point of infected groups have the same trend on cytokine transcription and secretion. Acording to RAW264.7, there is no significant regular pattern on apoptosis and cytokine secretion. Acording to THP-1, there is a increase with time on apoptosis of non-pathogenic strain, and there is a same trend on secretion of TNF-α, a opposite tendency on secretion of IL-6. Apoptosis of virulent strains is less than attenuated vaccine strain. Secretion of virulent strains is complex, which shows the increase first and then suppression.By the results of two macrophage apoptosis analysis, THP-1 is more suitable for M. tuberculosis immune mechanisms experiments. Macrophage apoptosis mechanism is a complex process, but it is inseparable with cytokine secretion that infected by different virulence strains. The critical period that play a role of escape for Mycobacterium tuberculosis is 12 h-24 h after infected. In this experiment, we study the relationship between cytokines and apoptosis of cells at different time points to provide new ideas for macrophage apoptosis mechanisms.