Immunologic memory to phosphorylcholine. VI. Heterogeneity in light chain gene expression

BALB/c mice immunized with phosphorylcholine‐conjugated keyhole limpet hemocy‐anin (PC‐KLH) produce two types of anti‐PC antibodies, designated group I and group II, which differ in their fine specificity and idiotype expression. Group I1 hybridomas can utilize V_H genes and V_L genes (in particular, V_ϰ1–3) distinct from those expressed in the group I‐like anti‐PC myelomas. Here we have analyzed additional anti‐PC hybridomas from BALB/c and (CBA/N × BALB/c)F₁ male mice and also anti‐PC antibodies purified from BALB/c and C57BL/6N antisera. Isoelectric focusing indicates that one of the group II hybridomas utilizes V_ϰ1–3 and that related L chains are expressed in a major portion of group II serum antibodies. Other group I1 antibodies in antisera express different L chains, some of which are presently unidentified. However, isoelectric focusing analysis also indicates that the L chains of some group I1 hybridomas and serum antibodies are related to those found in the group I anti‐PC myelomas and group I hybridoma and serum antibodies. In addition, one hybridoma was found to utilize λ2. Thus, it appears that the anti‐PC antibodies with group II‐like fine specificity can utilize a variety of V_L genes related to, or distinct from, those expressed in group I antibodies.