Eric J. Patzer

Delineation of a region of the human immunodeficiency virus type 1 gp120 glycoprotein critical for interaction with the CD4 receptor

The primary event in the infection of cells by HIV is the interaction between the viral envelope glycoprotein, gp120, and its cellular receptor, CD4. A recombinant form of gp120 was found to bind to a recombinant CD4 antigen with high affinity. Two gp120-specific murine monoclonal antibodies were able to block the interaction between gp120 and CD4. The gp120 epitope of one of these antibodies was isolated by immunoaffinity chromatography of acid-cleaved gp120 and shown to be contained within amino acids 397-439. Using in vitro mutagenesis, we have found that deletion of 12 amino acids from this region of gp120 leads to a complete loss of binding. In addition, a single amino acid substitution in this region results in significantly decreased binding, suggesting that sequences within this region are directly involved in the binding of gp120 to the CD4 receptor.

Radioimmunoassay for detection of VP1 specific neutralizing antibodies of foot and mouth disease virus

A solid-phase radioimmunoassay was developed for the detection of antibodies against a specific region of the VP1 protein of the A24 and 01 serotypes of foot and mouth disease virus. The antibody titers from the radioimmunoassay showed a positive correlation with neutralizing antibody titers determined by a mouse protection assay. The specificity of the assay resides in the peptide used as antigen. The assay is rapid, reproducible and does not require the use of whole virions.

Use of recombinant mammalian cell lines for vaccine production.

Antiviral vaccines classically were composed of attenuated or inactivated whole virions produced by infection of eukaryotic cells. With the advent of recombinant DNA (rDNA) technology, the strategy for vaccine production has changed dramatically. The gene(s) encoding a specific protein(s) containing the virus neutralizing site(s) can be isolated and transfected into bacteria, yeast or mammalian cells in culture. These transfected or recombinant organisms or cells can be exploited to produce large quantities of the specific protein which subsequently can be developed in a highly purified form for use as a subunit vaccine. The issue which we would like to discuss is the selection of the host used for the expression of recombinant subunit vaccines.