Ercole Rao

Trispecific broadly neutralizing HIV antibodies mediate potent SHIV protection in macaques

A triple threat for HIV The HIV virus continually evolves tricks to evade elimination by the host. Prevention and a cure will likely rely on broadly neutralizing antibodies that can recognize and conquer multiple viral strains or subtypes. Xu et al. engineered a single antibody molecule to recognize three highly conserved proteins needed for HIV infection (see the Perspective by Cohen and Corey). This “trispecific” antibody uses two sites (V1V2 and MPER) to bind HIV-infected cells, while the third site (CD4bs) recruits killer T lymphocytes that can eliminate the virus. When tested against >200 different HIV strains, trispecific antibodies were highly potent and broadly neutralized ∼99% of HIV viruses. This approach could potentially simplify HIV treatment regimens and improve therapy response. Science, this issue p. 85; see also p. 46 Engineered trispecific antibodies interact with three independent HIV-1 envelope determinants and prevent infection. The development of an effective AIDS vaccine has been challenging because of viral genetic diversity and the difficulty of generating broadly neutralizing antibodies (bnAbs). We engineered trispecific antibodies (Abs) that allow a single molecule to interact with three independent HIV-1 envelope determinants: the CD4 binding site, the membrane-proximal external region (MPER), and the V1V2 glycan site. Trispecific Abs exhibited higher potency and breadth than any previously described single bnAb, showed pharmacokinetics similar to those of human bnAbs, and conferred complete immunity against a mixture of simian-human immunodeficiency viruses (SHIVs) in nonhuman primates, in contrast to single bnAbs. Trispecific Abs thus constitute a platform to engage multiple therapeutic targets through a single protein, and they may be applicable for treatment of diverse diseases, including infections, cancer, and autoimmunity.