hsp65 mRNA+ macrophages and gamma delta T cells in influenza virus-infected mice depleted of the CD4+ and CD8+ lymphocyte subsets.

The effects of depleting CD4+ and CD8+ T cells on macrophage recruitment have been analyzed for bronchoalveolar lavage (BAL) populations from mice with primary or secondary influenza pneumonia. Macrophages were characterized by both the capacity to engulf latex particles and the expression of mRNA for a 65 kD heat shock protein (hsp65). The localization of hsp65 mRNA+ cells to the pneumonic lung was greatly enhanced in the secondary response. Eliminating the CD4+ and CD8+ T cells decreased the prevalence of hsp65 mRNA+latex+ macrophages as much as seven-fold, though the frequency of latex+ cells was higher in the residual inflammatory process. The CD4-8- gamma delta T cells were also relatively enriched in the BAL from the depleted mice. However, the localization of gamma delta T cells to the pneumonic lung does not compensate either quantitatively or qualitatively for the lack of the CD4+ and CD8+ alpha beta T-cell subsets, which are responsible for activating a substantial proportion of the phagocytic cells to express transcripts of an endogenous hsp65 gene.