Rothchild, Alissa C.Stowell, BritniGoyal, GirijaNunes-Alves, CláudioYang, QiantingPapavinasasundaram, KadambaSassetti, Christopher M.Dranoff, GlennChen, XinchunLee, JinheeBehar, Samuel M.2017-12-062017Rothchild, A. C., B. Stowell, G. Goyal, C. Nunes-Alves, Q. Yang, K. Papavinasasundaram, C. M. Sassetti, et al. 2017. “Role of Granulocyte-Macrophage Colony-Stimulating Factor Production by T Cells during Mycobacterium tuberculosis Infection.” mBio 8 (5): e01514-17. doi:10.1128/mBio.01514-17. http://dx.doi.org/10.1128/mBio.01514-17.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34492354ABSTRACT Mice deficient for granulocyte-macrophage colony-stimulating factor (GM-CSF−/−) are highly susceptible to infection with Mycobacterium tuberculosis, and clinical data have shown that anti-GM-CSF neutralizing antibodies can lead to increased susceptibility to tuberculosis in otherwise healthy people. GM-CSF activates human and murine macrophages to inhibit intracellular M. tuberculosis growth. We have previously shown that GM-CSF produced by iNKT cells inhibits growth of M. tuberculosis. However, the more general role of T cell-derived GM-CSF during infection has not been defined and how GM-CSF activates macrophages to inhibit bacterial growth is unknown. Here we demonstrate that, in addition to nonconventional T cells, conventional T cells also produce GM-CSF during M. tuberculosis infection. Early during infection, nonconventional iNKT cells and γδ T cells are the main source of GM-CSF, a role subsequently assumed by conventional CD4+ T cells as the infection progresses. M. tuberculosis-specific T cells producing GM-CSF are also detected in the peripheral blood of infected people. Under conditions where nonhematopoietic production of GM-CSF is deficient, T cell production of GM-CSF is protective and required for control of M. tuberculosis infection. However, GM-CSF is not required for T cell-mediated protection in settings where GM-CSF is produced by other cell types. Finally, using an in vitro macrophage infection model, we demonstrate that GM-CSF inhibition of M. tuberculosis growth requires the expression of peroxisome proliferator-activated receptor gamma (PPARγ). Thus, we identified GM-CSF production as a novel T cell effector function. These findings suggest that a strategy augmenting T cell production of GM-CSF could enhance host resistance against M. tuberculosis.en-USGM-CSFT cellscytokineslung infectionmacrophagesJournal Article2017-12-0610.1128/mBio.01514-17