Chang S P, Perlmutter R M, Brown M, Heusser C H, Hood L, Rittenberg M B
J Immunol. 1984 Mar;132(3):1550-5.
The anti-phosphocholine (PC) memory response elicited in BALB/c mice by phosphocholine-keyhole limpet hemocyanin (PC-KLH) contains two groups of antibodies distinguished by their fine specificity for PC and p-nitrophenylphosphocholine (NPPC). Group I antibodies are inhibited by both PC and NPPC, while Group II antibodies are inhibited appreciably only by NPPC; only Group I antibodies are dominated by the T15 idiotype. Anti-PC hybridomas representative of the memory response to PC-KLH were produced to examine the variable region genes expressed by memory B cells. Two IgM hybridomas were of the Group I type, because they were inhibited by both PC and NPPC and they bound to the pneumococcus R36A. However, only one of these antibodies (PCM-2) expressed a T15 idiotope, while the other (PCM-1) did not express any of three T15 idiotopes. Despite its negative T15 idiotype profile, N-terminal amino acid sequencing of PCM-1 purified heavy chain and Southern blots of the hybridoma DNA indicated that it utilizes the T15 VH and JH1 genes. Three hybridomas, IgG1, IgM, and IgE, typical of Group II antibodies, were examined; these were negative for three T15 idiotopes and displayed measurable avidity only for NPPC in a PC-protein binding inhibition assay. These three hybridoma antibodies, like serum Group II IgG1, did not measurably bind to the bacterium R36A. The heavy chain amino termini of all three of these antibodies were inaccessible for Edman degradation. Southern blots of DNA from the IgG1 hybridoma revealed the T15 VH gene to be in the germ line configuration only and unassociated with any JH segment, indicating that this Group II antibody utilizes a VH gene different from the T15 family. These results signify that, whereas some diversity of the (anti-PC) memory response may be generated by somatic diversification of variable regions important in the primary response, a significant contribution to the overall heterogeneity of memory antibodies originates in the expression of additional variable region genes.
磷酰胆碱-钥孔戚血蓝蛋白（PC-KLH）在BALB/c小鼠中引发的抗磷酰胆碱（PC）记忆反应包含两组抗体，它们对PC和对硝基苯基磷酰胆碱（NPPC）的精细特异性不同。I组抗体被PC和NPPC均抑制，而II组抗体仅被NPPC明显抑制；只有I组抗体以T15独特型为主。制备了代表对PC-KLH记忆反应的抗PC杂交瘤，以检测记忆B细胞表达的可变区基因。两个IgM杂交瘤属于I组类型，因为它们被PC和NPPC均抑制，并且它们与肺炎球菌R36A结合。然而，这些抗体中只有一个（PCM-2）表达T15独特型表位，而另一个（PCM-1）不表达三种T15独特型表位中的任何一种。尽管PCM-1的T15独特型谱为阴性，但其纯化重链的N端氨基酸测序和杂交瘤DNA的Southern印迹表明它利用T15 VH和JH1基因。检测了三个典型的II组抗体杂交瘤，IgG1、IgM和IgE；它们对三种T15独特型表位均为阴性，并且在PC-蛋白结合抑制试验中仅对NPPC显示出可测量的亲和力。这三种杂交瘤抗体，与血清II组IgG1一样，未检测到与细菌R36A的结合。这三种抗体的重链氨基末端均无法进行埃德曼降解。来自IgG1杂交瘤的DNA的Southern印迹显示T15 VH基因仅处于种系构型，且与任何JH片段无关，表明该II组抗体利用不同于T15家族的VH基因。这些结果表明，虽然（抗PC）记忆反应的一些多样性可能由初次反应中重要的可变区的体细胞多样化产生，但记忆抗体总体异质性的一个重要贡献源自额外可变区基因的表达。
