Comparison of changes in the percentages of CD8+CD28-TCRalpha beta+ T cell subpopulations in allergic asthma subjects vs controls before and after anti-CD3/anti-CD28/IL-2 stimulation in vitro.

Asthma is a chronic inflammatory disease characterized by the migration of activated T cells into the bronchial mucosa. TGF-beta and IL-10 have proved to regulate airway hyper-responsiveness and leukocytes recruitment to the airways of ovalbumin (OVA) sensitized mice. We examined relative changes in CD8+T cell subpopulations between fifty allergic asthma subjects and twenty five aged-matched healthy adults before and after anti-CD3/CD28 and IL-2 stimulation in the presence of IL-10 or TGF-beta, focusing on CD62L and FoxP3 expressing TCR alpha beta + cells. Severe asthma group had a significantly higher percentage of CD8+ CD28-and CD8+ CD28-TCR alpha beta + CD62L highFoxP3 bright T cells than other groups after enrichment. Compared to the baseline, co-stimulation with either IL-10 or TGF-beta increased the percentage of CD8+CD28-but decrease the percentage of CD8+CD28+T cells within anti-CD3/anti-CD28/IL-2 activated CD8+T cells in all groups. Co-stimulation with anti-CD3/anti-CD28/IL-2 in presence of either IL-10 or TGF-beta decreased the frequencies of CD8+CD28-TCR alpha beta +CD62Lhigh FoxP3 bright T cells in severe asthma subgroup but increased this parameter in other groups. We suggest that altered high level expression of CD62L and FoxP3 on CD8+ CD28-TCR alpha beta + T cell is relevant to allergic asthma. These data have implications for further characterization of CD8+ CD28-TCR alpha beta+ T cell subsets, with special emphasis on their implication in healthy or allergic immune response.