Publication

Abstract : In this study, histopathological features of pulmonary granuloma induced by trehalose 6, 6’dimycolate (TDM) of Mycobacterium tuberculosis bacilli in naive and lymphopenic mice are documented. Simultaneously, (a) proinflammatory cytokine (tumour necrosis factor alpha -TNF-α) and macrophage chemotactic factor (macrophage inflammatory protein 1 alpha – MIP-1α) concentrations in the lung homogenates were estimated by a sandwich enzyme-linked immunosorbent assay (ELISA), (b) chemotactic response of mouse peritoneal macrophages to TDM, are assayed. Non-caseating histiocytic granulomas in lungs as well as elevated TNF-α and MIP-1α concentrations in the lung homogenates were observed in naive mice. By contrast, lymphopenic mice showed no demonstrable granulomatous response to TDM and there was marked decrease in TNF-α and MIP1-α concentrations in the lung homogenates. The peritoneal macrophages of naive mice demonstrated optimum chemotactic response to TDM in vitro, while peritoneal macrophages of lymphopenic mice showed suboptimal chemotactic response to TDM. The results of this experimental study indicated that: (a) the pulmonary granuloma in mouse following TDM administration depends not only upon the production of TNF-α and MIP-1α in optimal amounts by the host, but also their participation during the active stages of granuloma formation; (b) TDM promotes chemotaxis of peritoneal macrophages in naive mice in vitro and this is facilitated by the MIP-1α