Liao N S, Raulet D H
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
J Immunol. 1992 Aug 15;149(4):1151-5.
Minor lymphocyte-stimulating (Mls) Ag are alloantigens that stimulate T cells expressing specific V beta regions. Recent studies have established that Mls Ag are examples of endogenous superantigens encoded by the products of endogenous mouse mammary tumor virus (MLV) genomes. In a mouse strain that expresses a given mammary tumor virus (Mls) Ag, reactive T cells expressing the corresponding V beta region are profoundly deficient, due at least in part to clonal deletion of the cells during their development. Expression of Mls and other endogenous superantigens, therefore, results in profound alterations in the ultimate repertoire of T cells in an animal. A role for endogenous superantigens in positive selection of T cells has not been previously established. Here we present evidence that expression of Mls-1a leads to a specific increase in the abundance of V beta 14+ T cells. Genetic studies indicate linkage of the effect to the Mls-1a gene. Neonatal tolerance studies argue against the possibility that the increase is due solely to the deletion of Mls-reactive V beta 14- T cells. The results are consistent with the Mls-1a product playing a role in the positive selection of V beta 14+ T cells.
微小淋巴细胞刺激（Mls）抗原是刺激表达特定Vβ区域的T细胞的同种异体抗原。最近的研究表明，Mls抗原是由内源性小鼠乳腺肿瘤病毒（MLV）基因组产物编码的内源性超抗原的实例。在表达给定乳腺肿瘤病毒（Mls）抗原的小鼠品系中，表达相应Vβ区域的反应性T细胞严重缺乏，至少部分原因是这些细胞在发育过程中的克隆性缺失。因此，Mls和其他内源性超抗原的表达会导致动物体内T细胞最终库的深刻改变。内源性超抗原在T细胞阳性选择中的作用此前尚未确定。在此，我们提供证据表明Mls-1a的表达导致Vβ14 + T细胞丰度的特异性增加。遗传学研究表明这种效应与Mls-1a基因连锁。新生期耐受性研究排除了这种增加仅仅是由于Mls反应性Vβ14 - T细胞缺失的可能性。这些结果与Mls-1a产物在Vβ14 + T细胞的阳性选择中起作用一致。
