Mucosal Immunol. 2010 Jan; 3(1):57-68.

PubMed ID: 19741600

Repeated vaginal administration of trimeric HIV-1 clade C gp140 induces serum and mucosal antibody responses

Cranage MP, Fraser CA, Stevens Z, Huting J, Chang M, Jeffs SA, Seaman MS, Cope A, Cole T, Shattock RJ

Vaccine-mediated prevention of primary infection with human immunodeficiency virus (HIV) may require the sustained production of antibody at mucosal portals of entry. Here, we describe a novel approach of repeated mucosal immunization by delivering an HIV-1 envelope glycoprotein (gp) in a gel formulated for intravaginal delivery. Rabbits were immunized over one to three 19-day cycles of intravaginal dosing with soluble recombinant trimeric HIV-1 clade C gp140 administered in Carbopol gel. The formulation was well tolerated. A single immunization cycle induced immunoglobulin G (IgG) antibody detected in the serum and female genital tract, and titers were boosted on further immunization. Vaccine-induced serum antibodies neutralized the infectivity of a pseudovirus carrying a heterologous clade C envelope. Our data prove the concept that repeated exposure of the female genital tract to HIV envelope can induce mucosally detectable antibody.