The T-cell-independent immune response to the hapten NP uses a large repertoire of heavy chain genes.

Hybridomas generated from C57BL/6 mice immunized with the hapten NP coupled to ficoll, a T-cell-independent carrier, produce monoclonal antibodies that use a large repertoire of VH regions and light chains. This contrasts with the homogeneity of the strain-specific response to NP observed with T-cell-dependent carriers, where most of the antibodies use a single VH region, V186.2, in combination with the lambda-1 light chain. There is no evidence for somatic mutation in any of the sequenced regions of the antibodies generated by NP-ficoll. Thus T cell participation is required for the homogeneity of the strain-specific hapten response, and probably for somatic mutation as well.