CLONAL NATURE OF IMMUNE-RESPONSE TO PHOSPHOCHOLINE .6. MOLECULAR UNIFORMITY OF A SINGLE IDIOTYPE AMONG BALB-C MICE

  • 1 January 1978
    • journal article
    • research article
    • Vol. 121  (4) , 1410-1415
Abstract
The molecular heterogeneity of Ig[immunoglobulin]G antibodies [Ab] to phosphocholine (PC) having a defined idiotype was examined in BALB/c mice immunized with PC-keyhole limpet hemocyanin (KLH). Specific Ab were separated by isoelectric focusing in polyacrylamide gels and characterized for PC-binding, idiotype and isotype by direct in situ labeling with 125I-labeled reagents followed by autoradiography. After immunization with PC-KLH, BALB/c produced 20-100 .mu.g/ml of IgM and 80-300 .mu.g/ml of IgG anti-PC Ab. The dominant fraction of anti-PC Ab in BALB/c (and a lesser fraction in other strains) possessed idiotypic determinants found on a PC-binding myeloma, TEPC15. Among 65 BALB/c examined, all produced an identical spectrotypic pattern of Ab possessing T15 idiotypic determinants. Three major sets of T15-idiotype bearing bands were observed, but they belonged to 3 different IgG subclasses: IgG1, IgG2 and IgG3. The germ line origin for this dominant set of Ab in the anti-PC repertoire of BALB/c was supported. The Ab may arise from a single rather than multiple VH[variable region of H-chain]-VL [variable region of L-chain] pairs.