Bacillus Calmette-Guérin enhances production and secretion of type IV collagenases in peripheral blood mononuclear cells

The effect of treatment with a protease inhibitor on mycobacterial infection

Mycobacterial infection occurs frequently in patients that receive protease inhibitors, which are drugs used to treat AIDS, but are known for metabolic effects. Proteases of microbial antigens have been recognized as important regulators of host inflammation and cellular response. To evaluate protease inhibitor effect on a mycobacterial infection, a pilot animal model was established. Mycobacterium bovis (bacillus Calmette-Guerin, or BCG) infection was compared in rats that received ritonavir and those that did not. Tissues and serum from one drug-treated and one control were analyzed weekly. Fewer acid-fast bacilli (AFBs) were consistently found in the drug-treated group by 3 separate measures: culture of tissue homogenates on solid media, tissue granuloma counts on organ sections, and staining of tissues for AFBs. Possible mechanisms of the observed relative resistance to BCG infection in ritonavir-treated rats were explored, by evaluating M. bovis cell wall lipids and proteins and by measuring infection-related cytokines in treated and control animals.

Effects of tumor necrosis factor-alpha and interferon-gamma on expressions of matrix metalloproteinase-2 and -9 in human bladder cancer cells

We have investigated the effects of tumor necrosis factor-alpha (TNF-alpha) and interferon (INF-gamma), the potent Bacillus Calmette-Guerin (BCG)-induced cytokines on the production of MMP-2, MMP-9, TIMP-1, TIMP-2 and MT1-MMP in high grade human bladder cancer cell lines, T-24, J-82 and HT-1376 cell lines. MMP-2 expression and activity were decreased in T-24 cells treated with both cytokines in a dose dependent manner. However, J-82 cells treated with TNF-alpha and INF-gamma revealed dose dependent increases of MMP-9 expression and activity with similar baseline expression and activity of MMP-2. HT-1376 cells after exposure to TNF-alpha only enhanced the expression and activity of MMP-9. These results indicate that TNF-alpha and INF-gamma could regulate the production of MMP-2 or MMP-9 on bladder cancer cells and their patterns of regulation are cell specific. Furthermore, this diverse response of bladder cancer cells to TNF-alpha and INF-gamma suggests that BCG immunotherapy may enhance the invasiveness of bladder cancer in certain conditions with induction of MMPs.