ABSTRACT
The initial reports describing the immunogenicity of antibodies in humans were concerned primarily with murine monoclonal antibodies (mAb). The immunogenicity of a given protein is dependent, at least in part, on its molecular size, its relative antigenic content and its residence time in the vascular compartment. Minimal Recognition Units are synthetic peptides comprising the complementary-determining regions (CDR) of the antibody molecules. The CDRs are the amino acid sequences of the hypervariable domains of an antibody and are responsible for antigen recognition. Chimeric mouse/human antibody molecules can be constructed by joining the entire variable domains of the murine mAb to the human Ig constant regions. A human mAb that has been extensively studied is HA-1A, an IgM reacting with the lipid A domain of endotoxin. The theoretical advantage of human mAbs is their lack of significant antigenicity in humans, and except for anti-idiotypic responses, human antibodies are not expected to be recognized as foreign by patients.
