Bernard G, Zoccola D, Ticchioni M, Breittmayer J P, Aussel C, Bernard A
Unité INSERM 343, Hôpital de l'Archet, Nice, France.
J Immunol. 1994 Jun 1;152(11):5161-70.
Cell-cell interactions play a central role during differentiation and development of the immune system. T or B lymphocyte homotypic adhesions can be induced via several surface molecules which, in some cases, are known to trigger the LFA-1/ICAM-1 adhesion pathway. We show here that mAbs reacting with the CD45 common epitopes or restricted RO epitope lead to a strong and rapid aggregation of all human thymocytes, and of T cell lines with an immature phenotype, but not of peripheral T lymphocytes. Aggregation requires energy, a physiologic temperature, Mg2+ divalent cations, and an intact cytoskeleton. It is LFA-1 dependent because CD11a and CD18 mAbs inhibit homotypic aggregation, whereas CD11b and CD11c mAbs do not. Homotypic thymocyte adhesion, however, is not decreased by CD54 mAb (anti-ICAM-1) but is inhibited by CDw50 mAb (anti-ICAM-3). Soluble CD22 fails to induce thymocyte adhesion, suggesting that CD45-induced aggregation is triggered by another ligand. Finally, because inhibitions observed with mAbs against LFA-1 and ICAM-3 are only partial, it can be assumed that another adhesion pathway is involved in thymocyte adhesion. The adhesion event specific for thymocytes we describe here is likely to play an important role in T cell differentiation.
细胞间相互作用在免疫系统的分化和发育过程中起着核心作用。T 或 B 淋巴细胞的同型黏附可通过多种表面分子诱导，在某些情况下，已知这些分子会触发 LFA-1/ICAM-1 黏附途径。我们在此表明，与 CD45 共同表位或限制性 RO 表位反应的单克隆抗体可导致所有人类胸腺细胞以及具有未成熟表型的 T 细胞系强烈且快速聚集，但不会导致外周 T 淋巴细胞聚集。聚集需要能量、生理温度、Mg2+ 二价阳离子和完整的细胞骨架。它依赖于 LFA-1，因为 CD11a 和 CD18 单克隆抗体可抑制同型聚集，而 CD11b 和 CD11c 单克隆抗体则不能。然而，同型胸腺细胞黏附不会因 CD54 单克隆抗体（抗 ICAM-1）而降低，但会被 CDw50 单克隆抗体（抗 ICAM-3）抑制。可溶性 CD22 无法诱导胸腺细胞黏附，这表明 CD45 诱导的聚集是由另一种配体触发的。最后，由于用抗 LFA-1 和 ICAM-3 的单克隆抗体观察到的抑制只是部分抑制，因此可以假设另一种黏附途径参与了胸腺细胞黏附。我们在此描述的胸腺细胞特异性黏附事件可能在 T 细胞分化中起重要作用。
