IFN-γ Increase Resistance Of BALB/c Mice To Mycobacterium Tuberculosis Infection

Objective To study the effect of IFN- Y on cytokines of murine infection with Mycobacterium tuberculosis.Methods The BALB/c mice infected with Mycobacterium tuberculosis were randomly divided into four groups and were treated with IFN- Y , LVFX, IFN- Y +LVFX and PBS, respectivesly. The following items were examined: l.the numbers of viable bacteria in liver, spleen and lung, 2.the pathology changs in lung and the survival times of the mice, 3.serum level of IFN-Y, DL-12, IL-18 and IL-4 were also examined by ELISA.Results The results showed that in the groups treated with IFN- Y , LVFX, IFN- Y and LVFX, the bacterial numbers in liver, spleen and lung were markedly reduced than those in control group. And so did in the lung lesions, especially in IFN- Y +LVFX combined treated group. The mean survival time was 70+11 days in group IFN-Y, 75+10 days in LVFX, 78+13 days in IFN- Y + LVFX combined group. Their mean survival time was longer than that of the control group 51+13 (p<0.01) . After the end of the 2nd week , serum levels of IFN- Y, IL-12 in the IFN-Y group were higher than those in the control group (p<0.05, p<0.01,respectively). After the end of the 4 week , serum levels of IL-12, IL-18 in IFN- Y group were higher than those in the control group (p<0.05). Serum levels of IFN-Y, IL-12, IL-18 in IFN-Y+LVFX group were higher than those in the control group(p<0.05,p< 0.05, p<0.01,respectively). After the end of the 6th week , serum levels of IFN- Y, EL-12 and EL-18 in all cytokine treated were higher than those in the control group. The level of IL-4 in all four groups were almost the same during the course of the experiment.Conclusions We got the conclusion from above studies that exogenous IFN- Y could promot reaction of Th1 cells and modulated the balance of Thl and Th2. It suggested that IFN- y could inhance the anti-tuberculosis protection in mice. And at the same times, the combined use of IFN- Y and LVFX in some extent may have the additive effects' in the teratment of Mycobacterium tuberculosis infection.