Figure 3.

Lung histopathology of wild-type, CD8α^−/−, TAP1^−/−, and β2-m^−/− mice at 4 weeks after challenge with 10⁶ MTB. (A) Wild-type mice have an interstitial pneumonitis composed of pronounced perivascular lymphocytic infiltration (arrowheads) accompanied by a diffuse histiocytic macrophage infiltrate (asterisk). (B) CD8^−/− mice present moderate perivascular and interstitial lymphocytic infiltration (arrowheads) and a prominent histiocytic cell response (asterisk). (C) TAP^−/− mice show modest numbers of perivascular lymphocytes (arrowhead) and manifest histiocytic cell infiltration (asterisk). (D) β2-m^−/− mice have an extensive pneumonitis, which is predominantly composed of diffused histiocytic infiltration (asterisk), and markedly lower numbers of perivascular lymphocytes (arrowheads).