Shimojo N, Cowan E P, Engelhard V H, Maloy W L, Coligan J E, Biddison W E
Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892.
J Immunol. 1989 Jul 15;143(2):558-64.
Previous studies have demonstrated that certain amino acid substitutions in the alpha two domain at positions 152 and 156 in the alpha two helix of the HLA-A2 molecule can affect presentation of the influenza virus matrix peptide M1 55-73 without abolishing binding of the M1 peptide. HLA-A2.1-restricted M1 55-73 peptide-specific CTL lines obtained from almost all HLA-A2.1+ individuals fail to recognize the M1 peptide presented by site-directed mutants of HLA-A2 that have either a Val----Ala or Val----Gln substitution at position 152 or a Leu----Trp substitution at position 156. Only one HLA-A2+ individual (donor Q66, HLA-A2,-B53,-B63) has been found who is able to generate a unique repertoire of HLA-A2-restricted M1 peptide-specific CTL that can recognize peptide presented by HLA-A2 mutants with either an Ala or Gln substitution at position 152 or a Trp substitution at position 156. These Q66 M1 peptide-specific CTL could be selected by stimulation with M1 peptide-pulsed transfectants that express the mutant HLA-A2 gene with the Trp substitution at 156. To determine if the presence of the unique CTL repertoire could be attributed to a variant HLA-A2 molecule in Q66, sequences were determined from polymerase chain reaction-amplified segments of the HLA-A2 RNA. Two different HLA-A2 genes were found expressed in Q66 cells: one is identical to HLA-A2.1 and the other is identical to HLA-A2.2F (Gln----Arg at position 43, Val----Leu at position 95, and Leu----Trp at position 156). These results demonstrate that a different CTL repertoire specific for HLA-A2 plus the M1 55-73 peptide is generated in an individual that expresses both HLA-A2.1 and HLA-A2.2F compared to individuals who express HLA-A2.1 alone, and that the unique repertoire can be selected by the presence of an HLA-A2 molecule with a single amino acid substitution at position 156.
先前的研究表明，HLA - A2分子α2螺旋中第152和156位的α2结构域中的某些氨基酸替换，可影响流感病毒基质肽M1 55 - 73的呈递，而不消除M1肽的结合。从几乎所有HLA - A2.1 +个体获得的HLA - A2.1限制性M1 55 - 73肽特异性CTL系，无法识别在第152位具有Val→Ala或Val→Gln替换，或在第156位具有Leu→Trp替换的HLA - A2定点突变体呈递的M1肽。仅发现一名HLA - A2 +个体（供体Q66，HLA - A2， - B53， - B63）能够产生独特的HLA - A2限制性M1肽特异性CTL库，该库能够识别在第152位具有Ala或Gln替换，或在第156位具有Trp替换的HLA - A2突变体呈递的肽。这些Q66 M1肽特异性CTL可通过用表达在第156位具有Trp替换的突变HLA - A2基因的M1肽脉冲转染细胞刺激来选择。为了确定独特CTL库的存在是否可归因于Q66中变异的HLA - A2分子，从HLA - A2 RNA的聚合酶链反应扩增片段中测定序列。在Q66细胞中发现表达两种不同的HLA - A2基因：一种与HLA - A2.1相同，另一种与HLA - A2.2F相同（第43位Gln→Arg，第95位Val→Leu，第156位Leu→Trp）。这些结果表明，与仅表达HLA - A2.1的个体相比，在同时表达HLA - A2.1和HLA - A2.2F的个体中产生了针对HLA - A2加M1 55 - 73肽的不同CTL库，并且独特的库可通过在第156位具有单个氨基酸替换的HLA - A2分子的存在来选择。
