BALB/C小鼠核小体H2B组蛋白Th细胞表位的鉴定

Identification of helper T lymphocyte cell epitope in nucleosome histone H2B of BALB/C mice

目的鉴定正常BALB/C小鼠核小体H2B组蛋白Th细胞表位.方法根据小鼠H2B确切氨基酸组成序列,利用计算机软件预测可能的Th细胞表位,体外固相合成,然后分别刺激BALB/C小鼠淋巴细胞,根据其中的Th细胞增生程度和白细胞介素(IL)-2分泌水平,判断实验肽是否为具有免疫活性的表位.结果共预测获得4条可能的核小体H2B组蛋白Th细胞表位,即H2B2～15、H2B14-28、H2B61～76和H2B99～113.其中H2B14-28能够明显刺激BALB/C小鼠Th淋巴细胞增生和分泌IL-2,且有明显剂量依赖关系.结论H2B14-28可能为BALB/c小鼠核小体H2B组蛋白Th细胞免疫优势表位之一.

Objective To identify Th cell epitopes in nucleosome histone H2B of BALB/C mice.Methods Based on the H2B amino acid residue consequences,potential H2B Th cell epitopes were predicted by a computer program and synthesized using F-moc solid-phase chemistry.In ex vivo recall experiment,the Th cell epitopes were identified using lymphocyte proliferation and IL-2secretion experiment.Results4potential H2B Th cell epitopes were predicted and they spanned H2B residues2～15,14～28,61～76and99～113.The peptide H2B 14～28 could significantly stimulate the proliferation and IL-2secretion of lymph node Th cells from BALB/C mice immunized with the same peptide.Moreover,their effect was dose-dependent.Conclusion The peptide H2B 14～28 represents one of the immunodominant nucleosomal Th cell epitopes of BALB/C mice.