SLA (swineleukocyteantigen )特异性CD4+T细胞系和自身APC以及猪PBMC共同孵育时 ,T细胞增殖反应很强 ,而同仅有自身APC或猪PBMC刺激时的T细胞增殖有显著差异。提示抗原特异性CD4+T细胞系以间接途径识别SLA抗原。该识别能被抗人CD4和HLAII类抗体阻断 ,而抗SLAII类抗体阻断作用很弱 ,表明HLAII类分子在间接识别中起重要作用 ,这一结果不同于直接从外周血中分离的未经抗原致敏的T细胞。直接识别猪APC递呈的抗原。有可能异种移植初期以直接识别为主导 ,随着移植物存活时间的延长逐渐转为间接识别 T cell proliferation response was strong when SLA (swineleukocyteantigen) -specific CD4 + T cells were co-incubated with their own APCs and porcine PBMCs, but significantly different from those stimulated with only APCs or porcine PBMCs. Suggesting that antigen-specific CD4 + T cell lines recognize SLA antigens indirectly. This recognition can be blocked by anti-human CD4 and HLA class II antibodies, while the anti-SLA class II antibody blockade is weak, indicating that HLA class II molecules play an important role in indirect recognition, a result that differs from the direct Antigen sensitized T cells. Direct identification of porcine APC presented antigen. It is possible that the early stage of xenotransplantation is dominated by direct recognition, which gradually turns to indirect recognition as the graft survival time prolongs