1. Murine polymorphonuclear neutrophils produce interferon-gamma in response to pulmonary infection with Nocardia asteroides.
- Author
-
Ellis TN and Beaman BL
- Subjects
- Animals, Enzyme-Linked Immunosorbent Assay, Female, Gene Expression, Interferon-gamma genetics, Interleukin-4 analysis, Mice, Mice, Inbred C57BL, Nocardia Infections microbiology, Nocardia Infections pathology, Nocardia asteroides isolation & purification, Pneumonia, Bacterial microbiology, Pneumonia, Bacterial pathology, Specific Pathogen-Free Organisms, Time Factors, Interferon-gamma biosynthesis, Nocardia Infections immunology, Nocardia asteroides immunology, Pneumonia, Bacterial immunology
- Abstract
Nocardia asteroides causes an acute, necrotizing pneumonia characterized by extensive infiltration of polymorphonuclear neutrophils (PMNs) into the lungs. Although PMNs have historically been classified as end-point cells, recent investigations have indicated that PMNs have the ability to secrete cytokines such as interleukin (IL)-4 and IL-12. This study investigated the ability of PMNs to produce cytokines in a murine model of N. asteroides pulmonary infection. Flow cytometric analysis demonstrated the production of interferon-gamma (IFN-gamma), but not IL-4, by PMNs in response to this infection. IFN-gamma production correlated with peak infiltration of PMNs into the lungs. Cell sorting and enzyme-linked immunosorbent assay were used to confirm cytokine production by cells with nuclear morphology characteristic of PMNs. This is the first report of IFN-gamma production by neutrophils in response to an infection in vivo. These results suggest that PMNs play an important role in directing the host toward a T helper cell type 1 phenotypic response in the lungs.
- Published
- 2002