Sharrow S O, Ozato K, Sachs D H
J Immunol. 1980 Nov;125(5):2263-8.
The expression of Ia antigens on murine thymocytes has been assessed by indirect immunofluorescence and flow microfluorometry analysis. Antisera specific for I-region determinants were found to react with at least 50% of thymus cells in single-cell suspensions. When these antisera were tested on thymus cells of an appropriate recombinant strain, it was found that both I-A and I-E/C subregion determinants could be detected. Monoclonal antibodies to I-A and to I-E determinants also reacted with thymus cells in a similar fashion, eliminating the possibility that contaminating specificities accounted for the reactivity of alloantisera. The majority of Ia-positive thymus cells appeared to express determinants encoded by genes of both I-A and I-E/C subregions. Ia expression on individual thymocytes was also correlated with cell size as measured by forward light scatter intensity. However, unlike antigens detected by rabbit anti-mouse brain antisera, Ia antigens did not appear to be associated with known subpopulations of thymocytes distinguishable by light scatter intensity. The presence of I-region encoded antigens on thymocytes may play a role in maturation of T cells in the thymus microenvironment.
通过间接免疫荧光和流式微量荧光分析评估了小鼠胸腺细胞上Ia抗原的表达。发现针对I区决定簇的抗血清可与单细胞悬液中至少50%的胸腺细胞发生反应。当在合适的重组品系的胸腺细胞上测试这些抗血清时，发现I-A和I-E/C亚区决定簇均可被检测到。针对I-A和I-E决定簇的单克隆抗体也以类似方式与胸腺细胞发生反应，排除了污染特异性导致同种抗血清反应性的可能性。大多数Ia阳性胸腺细胞似乎表达由I-A和I-E/C亚区基因编码的决定簇。单个胸腺细胞上的Ia表达也与通过前向光散射强度测量的细胞大小相关。然而，与兔抗鼠脑抗血清检测到的抗原不同，Ia抗原似乎与通过光散射强度可区分的已知胸腺细胞亚群无关。胸腺细胞上I区编码抗原的存在可能在胸腺微环境中T细胞的成熟中起作用。
