Kathleen N. Potter

Antibody Production in the Baculovirus Expression System

The proven ability of insect cells to produce murine and human antibodies renders the baculovirus system amenable to the synthesis of both naturally occurring antibodies and designed mutants. Study of these antibodies should provide a basis for rational antibody design useful in human therapy.

Staphylococcal Protein A Binding to VH3 Encoded Immunoglobulins

Staphylococcal protein A (SPA) is a B-cell superantigen which binds specifically to the variable region of human VH3 encoded antibodies. We undertook to identify the VH3 regions involved in the interaction with SPA by producing mutant antibodies in the baculovirus expression system. We had previously shown that a single amino acid change at position 57 in the CDR2 of a human SPA nonbinding VH3 encoded rheumatoid factor converted it to an SPA binder, implicating CDR2 in SPA binding. When regions of the mutated binder were exchanged with those from a mouse nonbinding antibody, the pattern of SPA binding indicated that residues in FR1, CDR2 and FR3 are involved in the interaction between VH3 encoded antibodies and SPA. In addition, all three regions are simultaneously required for SPA binding to occur. When any one of the three regions was altered, SPA binding was severely disrupted.

Immunoglobulin variable region gene segments in human autoantibodies

Publisher Summary Auto-antibodies are frequently produced by the normal immune system. However, auto-immunity results from a disturbance of the control mechanisms. Genetic analysis of auto-antibodies indicates that the gene segments used by autoantibodies derive from the same repertoire as those used by the normal immune system to exogenous antigens. This chapter discusses gene segment usage by autoantibodies as compared with the normal repertoire and the functional significance of the idiotypes formed in the expressed immunoglobulins. Auto-immunity is not the sole result of heredity, but depends on the interaction of multiple gene products and environmental factors. The variable regions of immunoglobulin light (L) and heavy (H) chains are assembled in an ordered fashion from three multigene families of DNA segments as the variable (V), diversity (D), and joining (J) gene segments. The analysis of auto-antibodies, their gene segment usage, and idiotypes have potential clinical significance as the Ids on neoplastic B-cells provide tumor antigens for vaccination of patients with B-cell tumors.