Abstract: Novel methods for producing, and compositions of, humanized immunoglobulins having one or more complementarity determining regions (CDR's) and possible additional amino acids from a donor immunoglobulin and a framework region from an accepting human immunoglobulin are provided. Each humanized immunoglobulin chain will usually comprise, in addition to the CDR's, amino acids from the donor immunoglobulin framework that are, e.g., capable of interacting with the CDR's to effect binding affinity, such as one or more amino acids which are immediately adjacent to a CDR in the donor immunoglobulin or those within about 3 .ANG. as predicted by molecular modeling. The heavy and light chains may each be designed by using any one or all of various position criteria.

Abstract: Chimeric molecules having a ligand component linked to an immunoglobulin constant region component are provided for various diagnostic, therapeutic and other uses. These immunoligands can exhibit the high degree of specificity associated with the ligand, yet retain various effector functions characteristic of immunoglobulin heavy chains.

Abstract: Soluble antigens useful for efficient production of antibodies against human T-cell receptor epitopes are provided. A preferred antigen is a chimeric polypeptide comprising at least 100 amino acids from a V.beta. domain with solubility conferred by an immunoglobulin heavy chain CH2 or CH3 domain fused thereto. Product antibodies and methods for diagnostic and therapeutic uses for both antigens and antibodies are provided.

Abstract: Improved means for producing Clostridium Phospholipase C (PL) polypeptides based on the cloning and expression of recombinant DNA segments containing Clostridium PLC genes and fragments. The DNA segments are operably linked to host specific expression control sequences for exogenous production of Clostridium PLC, or fragments thereof, substantially free from naturally-associated Clostridium gene products.