| First Author | Ngai P | Year | 2007 |
| Journal | Infect Immun | Volume | 75 |
| Issue | 5 | Pages | 2244-52 |
| PubMed ID | 17307945 | Mgi Jnum | J:121875 |
| Mgi Id | MGI:3712585 | Doi | 10.1128/IAI.00024-07 |
| Citation | Ngai P, et al. (2007) Gamma interferon responses of CD4 and CD8 T-cell subsets are quantitatively different and independent of each other during pulmonary Mycobacterium bovis BCG infection. Infect Immun 75(5):2244-52 |
| abstractText | Gamma interferon (IFN-gamma) is a key cytokine in host defense against intracellular mycobacterial infection. It has been believed that both CD4 and CD8 T cells are the primary sources of IFN-gamma. However, the relative contributions of CD4 and CD8 T-cell subsets to IFN-gamma production and the relationship between CD4 and CD8 T-cell activation have not been examined. By using a model of pulmonary mycobacterial infection and various immunodetection assays, we found that CD4 T cells mounted a much stronger IFN-gamma response than CD8 T cells at various times after mycobacterial infection, and this pronounced IFN-gamma production by CD4 T cells was attributed to both greater numbers of antigen-specific CD4 T cells and a greater IFN-gamma secretion capacity of these cells. By using major histocompatibility complex class II-deficient or CD4-deficient mice, we found that the lack of CD4 T cells did not negatively affect primary or secondary CD8 T-cell IFN-gamma responses. The CD8 T cells activated in the absence of CD4 T cells were capable of immune protection against secondary mycobacterial challenge. Our results suggest that, whereas both CD4 and CD8 T cells are capable of IFN-gamma production, the former represent a much greater cellular source of IFN-gamma. Moreover, during mycobacterial infection, CD8 T-cell IFN-gamma responses and activation are independent of CD4 T-cell activation. |
