BACKGROUND: CD64 and CD206 receptors play an important role in the internalization of Mycobacterium tuberculosis into macrophages. RAGE, described in diabetes (a predisposing factor for tuberculosis), captures glycosylated proteins. METHODS: Four groups of 15 patients with type 2 diabetes mellitus (DM2), pulmonary tuberculosis (PTB), type 2 diabetes and pulmonary tuberculosis (DM2-PTB), and controls (CG) were studied. Blood was obtained and mononuclear cells (MNC) isolated and cultured to obtain adherent cells (AC) and then stimulated with M. tuberculosis H37Rv lipids. Expression of CD64, CD206 and RAGE was measured by flow cytometry. RESULTS: In the groups without stimulus, PTB and DM2-PTB expressed greater mean fluorescence intensity (MFI) of CD64 and CD206 compared to CG. DM2-PTB showed a decrease in expression compared to PTB. After lipid stimulation no significant difference between groups occurred. In AC without stimulus, RAGE expression was significantly greater in DM2, PTB and DM2-PTB. When DM2-PTB was compared to PTB, a significant decrease in expression occurred. After lipid stimulation, only DM2 cells showed greater MFI. CONCLUSIONS: Diabetes affects expression of the three receptors. PTB cells significantly increase them. Diabetes and tuberculosis infection decrease expression compared to PTB alone. Diabetes did not alter CD64 and CD206 expression in infected patients. RAGE expression increases in patients with PTB as well as in diabetics. This suggests that RAGE could also behave as a receptor for M. tuberculosis.
BACKGROUND:CD64 and CD206 receptors play an important role in the internalization of Mycobacterium tuberculosis into macrophages. RAGE, described in diabetes (a predisposing factor for tuberculosis), captures glycosylated proteins. METHODS: Four groups of 15 patients with type 2 diabetes mellitus (DM2), pulmonary tuberculosis (PTB), type 2 diabetes and pulmonary tuberculosis (DM2-PTB), and controls (CG) were studied. Blood was obtained and mononuclear cells (MNC) isolated and cultured to obtain adherent cells (AC) and then stimulated with M. tuberculosis H37Rv lipids. Expression of CD64, CD206 and RAGE was measured by flow cytometry. RESULTS: In the groups without stimulus, PTB and DM2-PTB expressed greater mean fluorescence intensity (MFI) of CD64 and CD206 compared to CG. DM2-PTB showed a decrease in expression compared to PTB. After lipid stimulation no significant difference between groups occurred. In AC without stimulus, RAGE expression was significantly greater in DM2, PTB and DM2-PTB. When DM2-PTB was compared to PTB, a significant decrease in expression occurred. After lipid stimulation, only DM2 cells showed greater MFI. CONCLUSIONS:Diabetes affects expression of the three receptors. PTB cells significantly increase them. Diabetes and tuberculosis infection decrease expression compared to PTB alone. Diabetes did not alter CD64 and CD206 expression in infected patients. RAGE expression increases in patients with PTB as well as in diabetics. This suggests that RAGE could also behave as a receptor for M. tuberculosis.