Cytokine profiles in immunocompetent persons infected with Mycobacterium avium complex

To evaluate the immunologic factors that contribute to protection against M ycobacterium avium complex (MAC), cytokine production by peripheral blood m ononuclear cells (PBMC) from human immunodeficiency virus-negative persons with pulmonary MAC (MAC patients) and healthy control subjects with a delay ed hypersensitivity skin test response to M. avium sensitin (MAS-positive c ontrol subjects) was measured. In MAC patients, mycobacterium-stimulated PB MC produced higher concentrations of interleukin (IL)-10 but lower concentr ations of interferon (IFN)-gamma, IL-12, and tumor necrosis factor (TNF)-al pha, compared with PBMC from MAS-positive control subjects. Immunolabeling for intracellular IL-10 revealed that this cytokine was produced by both mo nocytes and T cells. Alveolar macrophages produced TNF-alpha and IL-10 in r esponse to MAC, which suggests that these cytokines are produced in the lun gs of patients with pulmonary disease caused by this pathogen. Our findings suggest that IFN-gamma, TNF-alpha, and IL-12 contribute to protection agai nst MAC, whereas IL-10 is immunosuppressive.