Is a fatty acid transporter, CD36, involved in Mycobacterium tuberculosis infection?

CD36是一种氧化LDL受体和脂肪酸转运蛋白，在包括巨噬细胞在内的多种组织和细胞中表达。因为结核分枝杆菌在进入巨噬细胞、细胞内生长和从溶酶体逃逸时需要脂肪酸。本研究探讨了CD36在结核分枝杆菌感染人巨噬细胞中的可能作用。正常和cd36阴性受试者单核细胞来源的巨噬细胞体外感染结核分枝杆菌。正常和cd36阴性受试者对结核分枝杆菌感染的易感性无差异。单克隆抗cd36抗体对巨噬细胞感染结核分枝杆菌无明显抑制作用。激光共聚焦显微镜未见CD36与结核分枝杆菌有明显关系。因此，本研究未观察到CD36与结核分枝杆菌感染之间的明确关系。然而，感染似乎改变了巨噬细胞的脂肪酸组成，以及CD36和PPARgamma基因的表达水平。由于这两个基因对细胞内脂肪代谢和转运都有显著影响，CD36在结核分枝杆菌感染巨噬细胞中的间接作用还有待检验。

CD36 is an oxidized LDL receptor and a fatty acid transporter expressed in various tissues and cells, including macrophages. Since M.tuberculosis requires fatty acid in its entry into macrophages, intracellular growth, and escape from lysosomes. In the present study, possible role of CD36 in M.tuberculosis infection to human macrophages was examined. Monocyte-derived macrophages from normal and CD36-negative subjects were infected with M.tuberculosis in vitro. The susceptibility to M.tuberculosis infection was not different between normal and CD36-negative subjects. Further, monoclonal anti-CD36 antibody did not show significant suppressive effect on the infection of M.tuberculosis to macrophages. Confocal laser microscopy did not show any significant relation between CD36 and M.tuberculosis. Thus, no definite relation between CD36 and M.tuberculosis infection was observed in this stud. However, the infection appeared to change macrophageal fatty acid composition, and also the expression levels of CD36 and PPARgamma genes. Since he both genes have significant effects on intracellular fatty metabolism and transport, possible indirect role of CD36 in M.tuberculosis infection to macrophages remains to be tested.