Ando T, Yoshikai Y, Matsuzaki G, Takimoto H, Nomoto K
Department of Immunology, Kyushu University, Fukuoka, Japan.
Immunology. 1991 Dec;74(4):638-44.
In flow microfluorometry analysis of thymus and lymph node cells of C57BL/6(I-E-,Mlsb) mice rendered neonatally tolerant to (C57BL/6 x AKR/J)F1 (I-E+,Mlsb/a) lymphoid cells, both CD4+ and CD8+ cells showed a striking reduction in the number of V beta 6+ cells capable of recognizing Mlsa in the context of major histocompatibility complex (MHC) class II molecules, indicating that clonal deletion of V beta 6+ cells by Mlsa antigen occurs just at a stage of immature V beta 6lowCD4+CD8+ thymocytes. On the other hand, the number of V beta 11+ cells capable of recognizing I-E was markedly reduced in CD4+ cells, but CD8+ cells showed only partial (20%) reduction of such a population. The clonal deletion of V beta 11+ cells by I-E may begin at the transitional stage from V beta 11lowCD4+CD8+ to V beta 11highCD4+CD8- single-position cells, and V beta 11lowCD4+CD8+ cells differentiating to V beta 11highCD4-CD8+ cells seem to be resistant to clonal deletion. V beta 11+ T cells are also stimulated by staphylococcal enterotoxin A (SEA) irrespective of expression of CD4 or CD8. Nearly all of both V beta 11+CD4+ and V beta 11+CD8+ lymph node T cells were deleted by the injection of SEA every other day from birth. In their thymi, both V beta 11+CD4+CD8- and V beta 11+CD4-CD8+ single-positive thymocytes were deleted, and the proportion of V beta 11low thymocytes was lower than that of normal mice. The clonal deletion of V beta 11+ T cells by SEA injection occurs at a stage of immature V beta 11lowCD4+CD8+ double-positive thymocytes, resulting in deletion of both V beta 11+CD4+ and V beta 11+CD8+ T cells.
在对新生期耐受（C57BL/6×AKR/J）F1（I-E⁺，Mlsb/a）淋巴细胞的C57BL/6（I-E⁻，Mlsb）小鼠的胸腺和淋巴结细胞进行流式微量荧光分析时，CD4⁺和CD8⁺细胞中能够在主要组织相容性复合体（MHC）II类分子背景下识别Mlsa的Vβ6⁺细胞数量均显著减少，这表明Mlsa抗原对Vβ6⁺细胞的克隆清除恰好在未成熟的Vβ6lowCD4⁺CD8⁺胸腺细胞阶段发生。另一方面，能够识别I-E的Vβ11⁺细胞数量在CD4⁺细胞中显著减少，但CD8⁺细胞中此类细胞群体仅部分（20%）减少。I-E对Vβ11⁺细胞的克隆清除可能始于从Vβ11lowCD4⁺CD8⁺向Vβ11highCD4⁺CD8⁻单阳性细胞的过渡阶段，而分化为Vβ11highCD4⁻CD8⁺细胞的Vβ11lowCD4⁺CD8⁺细胞似乎对克隆清除具有抗性。Vβ11⁺T细胞也会受到葡萄球菌肠毒素A（SEA）的刺激，与CD4或CD8的表达无关。从出生起每隔一天注射SEA可使几乎所有的Vβ11⁺CD4⁺和Vβ11⁺CD8⁺淋巴结T细胞被清除。在它们的胸腺中，Vβ11⁺CD4⁺CD8⁻和Vβ11⁺CD4⁻CD8⁺单阳性胸腺细胞均被清除，且Vβ11low胸腺细胞的比例低于正常小鼠。通过注射SEA对Vβ11⁺T细胞的克隆清除发生在未成熟的Vβ11lowCD4⁺CD8⁺双阳性胸腺细胞阶段，导致Vβ11⁺CD4⁺和Vβ11⁺CD8⁺T细胞均被清除。
