In vitro, with the first signal present, B7.2(IgV+C) and IgV peptide fragments could simulate the costimulatory function to activate peripheral T lymphocytes.Conclusions: 1 .

• 3．利用 T细胞增殖试验证明，在第一信号存在条件下，B7．2（IgV+C)和 IgV肽段可协同第一信号激活外用血T淋巴细胞。