Immunoglobulin G3 from Polyclonal Human Immunodeficiency Virus (HIV) Immune Globulin Is More Potent than Other Subclasses in Neutralizing HIV Type 1

• DOI: 10.1128/jvi.75.14.6558-6565.2001
• Publication Date: 2002-07-27T10:06:37Z
• Authors: Orit Scharf; Hana Golding; Lisa R. King; Nancy Eller; Doug Frazier; Basil Golding; Dorothy E. Scott
• Keywords: Polyclonal antibodies

Passive antibody prophylaxis against human immunodeficiency virus type 1 (HIV-1) has been accomplished in primates, suggesting that this strategy may prove useful humans. While specificity is crucial for neutralization, other characteristics, such as subclass, have not explored. Our objective was to compare the efficiencies of immunoglobulin G (IgG) subclasses from polyclonal HIV immune globulin (HIVIG) neutralization HIV-1 strains differing coreceptor tropism. IgG1, IgG2, and IgG3 were enriched HIVIG by using protein A-Sepharose. All three bound major proteins, shown Western blot assay enzyme-linked immunosorbent assay. In fusion assays X4, R5, or X4R5 envelope-expressing effector cells, more efficiently blocked fusion. with cell-free viruses X4 (LAI, IIIB), R5 (BaL), (DH123), a similar hierarchy found: > IgG1 IgG2. longer, flexible hinge region than subclasses. To test whether important, digested pepsin generate F(ab')(2) fragments papain Fab fragments. still efficient IgG1. However, demonstrated equivalent capacities advantage lost. These results suggest confers enhanced HIV-neutralizing ability. Enrichment stabilization therefore lead improved preparations. The study implications improvement passive immunization monoclonal antibodies vaccines which induce high-titer responses could be advantageous.