Figure 3
Staining pattern of mycobacterial Mce1A antigen in human pulmonary tissues infected with M. tuberculosis as detected by immunohistochemical staining. Panels A-C shows three different infiltrates from the same lung section, the area marked in C is shown in higher magnification in D and the two demarcated areas in panel D are magnified in panels E-F. The expression of Mce1A was relatively lower as compared to the other secreted antigens. One of the infiltrates did not contain this antigen, while the expression of other secreted antigens was abundant in this infiltrate (as shown in Figure 1). The other two infiltrates expressed this antigen at a relatively lower level as compared to the other secreted antigens. The lung parenchyma in vicinity of the infiltrates expressed this antigen more abundantly as compared to the other secreted antigens. Alveolar macrophages, activated macrophages, and alveolar lining cells expressed the antigen.