BINDING OF FELINE IMMUNODEFICIENCY VIRAL GAG-P24 POLYPEPTIDE TO NONIMMUNE IGS

Available data on the existence of lentivirus proteins with properties of unconventional Ag for B cells, have been so far restricted to huma n immunodeficiency virus (i.e. gp-120 of HIV-I). By using biotinylated -MAbs-anti-biotin IgG as readout system, we now report that gag-p24 an tigen, either assembled in feline immunodeficiecy virus (FIV) particle s or expressed as recombinant polypeptide (rec.p24) may bind to nonimm une IgGs purified from mouse or cat sera. Moreover, FAGS scanning expe riments are consistent with the possibility that rec.p24 interacts wit h surface-Ig in a sub-population (5-6%) of rodent B cells. We hypothes ize that gag-p24 peptide encoded regions may bind to unconventional Ig sites or, alternatively, that they may represent 'public' epitopes fo r natural polyreactive antibody. (C) 1998 Elsevier Science B.V. All ri ghts reserved.