MOLECULAR AND GENE TRANSFER STUDIES OF ANTI-(TYROSINE, GLUTAMIC ACID)-ALANINE--LYSINE HYBRIDOMA ANTIBODIES FROM C57BL/10 MICE (GERMLINE, SOMATIC MUTATION, DNA)

A major function of the humoral immune system of higher vertebrates is to synthesize antibodies or immunoglobulin (Ig) molecules. These antibodies are responsible for binding a great number of foreign substances and rendering them harmless to the host organism. Most mammalian species (and other vertebrates as well) have the genetic capacity to generate 10('6) to 10('8) kinds of Ig molecules, each of which has a unique antigen-binding potential.; The studies presented here represent a dissection and reassembly of the immune response to the synthetic polypeptide antigen (T,G)-A--L. The first part of this work deals with the molecular biology of the murine response to (T,G)-A--L. Hybridoma cell lines secreting anti-(T,G)-A--L antibody have been generated and cloned. The phenotype of this response is of limited heterogeneity. The light chain restriction enzyme pattern is similar if not identical in most cell lines tested. Heavy chain patterns are more complex. Cloning and sequencing three of these genes has partially resolved the question of how this complexity arises. These hybridomas have rearranged the same germline Vh gene (186-2) but are heterogeneous with respect to the diversity (D) gene and joining (J) gene. Somatic mutations have taken place throughout the V gene and I have shown strong evidence to support parallel mutations in the complementarity-determining regions (CDR) 1 and 2.; The second part of this work describes studies of DNA-mediated gene transfer experiments transfecting heavy chain genes into a lymphoid variant cell line which secretes only anti-(T,G)-A--L light chains. These studies show that chimeric antibodies (Vh gene product from one hybridoma cell spliced to the C gene from another cell and associated with light chains from yet another cell) can be synthesized and secreted from host cells using gene transfer techniques. By using these transfectomas it will be possible eventually to study the function of novel chain and structures created in vitro and replanted in vivo for expression. These molecules have great potential as immunoregulatory and therapeutic agents.