INDUCTION OF HOMOLOGOUS VIRUS NEUTRALIZING ANTIBODIES IN GUINEA-PIGS IMMUNIZED WITH 2 HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 GLYCOPROTEIN GP120-ISCOM PREPARATIONS - A COMPARISON WITH OTHER ADJUVANT SYSTEMS

The immunogenicity in guinea-pigs of the human immunodeficiency virus type 1 envelope glycoprotein gp120 in immune stimulating complex (isco m) was compared to that of gp120 adjuvanted with QuilA-matrix (iscom w ithout attached antigen), aluminium hydroxide (alum) and the Ribi adju vant system. Gp120 was either incorporated into iscoms by covalent con jugation (iscom(c)) or by acid treatment of gp120 (iscom(a)) and both these preparations induced high ELISA antibody titres to gp120. Virus neutralizing (VN) antibodies were most frequently induced by gp120 in iscom(c), iscom(a) or in alum and correlated to high titres to the V3- region of gp120. Further, antibodies induced by gp120-iscom(c) most ef ficiently inhibited binding of a VN monoclonal antibody GP13 to the CD 4 binding region of gp120 whereas gp120-iscom(a) induced the highest m ean titre of antibodies blocking the binding of [I-125]gp120 to CD4. T hese results suggest that the gp120-iscom preparations efficiently ind uced high levels of gp120 specific antibodies and that the adjuvant fo rmulation of gp120 affect the specificity and functional properties of elicited antibodies. Copyright (C) 1996 Published by Elsevier Science Ltd.