Barnaba V, Watts C, de Boer M, Lane P, Lanzavecchia A
Fondazione A. Cesalpino, Basel, Switzerland.
Eur J Immunol. 1994 Jan;24(1):71-5. doi: 10.1002/eji.1830240112.
Activated human T cells express class II molecules, but their capacity to present soluble antigens and stimulate T cells has been repeatedly questioned. Two lines of evidence indicate that T cells may indeed function as professional antigen-presenting cells. First, T cells that have been recently activated can efficiently capture, process and present tetanus toxoid to class II-restricted T cell clones. This capacity correlates with the rate of class II synthesis. Second, activated T cell clones express high levels of B7, are powerful stimulators in mixed lymphocyte reactions, and their stimulatory capacity is inhibited by soluble CTLA4 or anti-B7 antibody. Furthermore, expression of B7 can be detected in vivo on T cells from biopsies of patients with liver disease. Presentation of soluble antigen by activated T cells may play a role in the amplification of the specific response, and possibly in immunopathological states.
活化的人类T细胞表达II类分子，但其呈递可溶性抗原并刺激T细胞的能力一直受到质疑。有两条证据表明T细胞确实可能作为专职抗原呈递细胞发挥作用。首先，最近被活化的T细胞能够有效地捕获、加工并将破伤风类毒素呈递给II类限制性T细胞克隆。这种能力与II类分子的合成速率相关。其次，活化的T细胞克隆表达高水平的B7，在混合淋巴细胞反应中是强大的刺激物，并且其刺激能力受到可溶性CTLA4或抗B7抗体的抑制。此外，在患有肝病患者活检组织的T细胞上可在体内检测到B7的表达。活化的T细胞呈递可溶性抗原可能在特异性反应的放大中起作用，并且可能在免疫病理状态中起作用。
