Chemokine receptor 2 serves an early and essential role in resistance to Mycobacterium tuberculosis

W Peters, HM Scott, HF Chambers… - Proceedings of the …, 2001 - National Acad Sciences
W Peters, HM Scott, HF Chambers, JAL Flynn, IF Charo, JD Ernst
Proceedings of the National Academy of Sciences, 2001National Acad Sciences
Although the protective cellular immune response to Mycobacterium tuberculosis requires
recruitment of macrophages and T lymphocytes to the site of infection, the signals that
regulate this trafficking have not been defined. We investigated the role of CC chemokine
receptor 2 (CCR2)-dependent cell recruitment in the protective response to M. tuberculosis.
CCR2−/− mice died early after infection and had 100-fold more bacteria in their lungs than
did CCR2+/+ mice. CCR2−/− mice exhibited an early defect in macrophage recruitment to …
Although the protective cellular immune response to Mycobacterium tuberculosis requires recruitment of macrophages and T lymphocytes to the site of infection, the signals that regulate this trafficking have not been defined. We investigated the role of C-C chemokine receptor 2 (CCR2)-dependent cell recruitment in the protective response to M. tuberculosis. CCR2−/− mice died early after infection and had 100-fold more bacteria in their lungs than did CCR2+/+ mice. CCR2−/− mice exhibited an early defect in macrophage recruitment to the lung and a later defect in recruitment of dendritic cells and T cells to the lung. CCR2−/− mice also had fewer macrophages and dendritic cells recruited to the mediastinal lymph node (MLN) after infection. T cell migration through the MLN was similar in CCR2−/− and CCR2+/+ mice. However, T cell priming was delayed in the MLNs of the CCR2−/− mice, and fewer CD4+ and CD8+ T cells primed to produce IFN-γ accumulated in the lungs of the CCR2−/− mice. These data demonstrate that cellular responses mediated by activation of CCR2 are essential in the initial immune response and control of infection with M. tuberculosis.
National Acad Sciences