Role of Valpha24JalphaQ TCR T Cells in the Pathogenesis of Asthma

特应性疾病是由产生IL-4和IL-5的辅助性T细胞2（Th 2）的激活失调引起的。因为IL-4的存在有效地增强幼稚T细胞向Th 2细胞的分化，所以寻找为幼稚T细胞提供IL- 4的细胞群是重要的。最近，一个独特的T细胞亚群，自然杀伤（NK）T细胞，已被证明产生大量的IL-4激活后，这表明它们在启动Th 2细胞分化的调节作用。为了确定NK T细胞是否在人类Th 2疾病中发挥作用，我们分析了哮喘和特应性皮炎（AD）患者的NK T细胞。我们对不变的Valpha 24 JalphaQ CD 4 ^-CD 8 ^- T细胞（可能是人类NK T细胞）进行了频率分析，发现哮喘和AD患者的NK T细胞显著减少。此外，我们发现来自健康受试者的大多数人类NK T细胞在活化时产生IFN-γ，但不产生IL-4。总之，这些结果表明，产生IFN-γ的NK T细胞的减少可能参与了特应性疾病如哮喘和AD的发病机制。

Atopic disorders are caused by disregulated activation of T helper 2 (Th2) cells that produce IL-4 and IL-5, Because the presence of IL-4 potently augments the differentiation of naive T cells into Th2 cells, it is important to seek the cell population which provides IL- 4 for naive T cells. Recently, a unique subpopulation of T cells, natural killer (NK) T cells, has been shown to produce a large amount of IL-4 upon activation, suggesting their regulatory role in initiation of Th2 cell differentiation. To determine whether NK T cells play a role in human Th2 diseases, we analyzed the NK T cells in patients with asthma and atopic dermatitis (AD). We performed a frequency analysis of the invariant Valpha24JalphaQ CD4^-CD8^- T cells, probable human NK T cells, and found that the NK T cells are significantly decreased in patients with asthma and AD.In addition, we found that the majority of human NK T cells from healthy subjects produce IFN-gamma but not IL-4 upon activation. Taken together, these results suggest that the decrease of NK T cells, which produce IFN-y, may be involved in the pathogenesis of atopic diseases, such as asthma and AD.