Interaction Between Mycobacteriophage D29and Macrophages And Its Distribution

Objective To study the interaction between Mycobacteriophage D29and macrophages and to measure the titer variation of D29both inside and outside the Mycobacterium tuberculosis(MTB) which was phagocytised by macrophages, so as to provide experiment references for studying on the mechanism and therapy dose for treating tuberculosis.Methods The macrophages cultured in vitro were cracked at different time after D29was mixed to estimate the titers of D29,at the same time, the supernatant fluid was collected after coincubated for12h to detect the levels of NO and IL-12by enzyme-linked immunosorbent assay(ELISA); the titers of D29were calculated both inside and outside the MTB by fluorescence quantitative PCR at different time after coincubated with macrophages which had phagocytised MTB.Results There were about2.5×104PFU of D29phagocytised by macrophages after coincubated with1×10PFU for20min, many of them were inactive after180min, there were few active D29at190min; the supernatant IL-12and NO levels had no significant differences between D29group and blank control group, but they were significantly lower than those in LPS positive group (P＜0.05); D29could enter MTB phagocytised by macrophages after coincubated for30min, when coincubated for40min and50min, the titers of D29were increased both inside and outside the MTB, then were decreased, they began to decrease largely at190min and210min, while at48h D29couldn’t be detected.Conclusion D29might be inactive after phagocytised by macrophages, and D29could not influence the immunologic function of macrophages; D29can enter MTB phagocytised by macrophages, at first, with the prolongation of the time, the number of D29in MTB is increased, afterwards, D29begins to decrease and disappears after48h.