Delayed vaginal SHIV infection in VRC01 and anti-α4β7 treated rhesus macaques

PLoS Pathog. 2019 May 13;15(5):e1007776. doi: 10.1371/journal.ppat.1007776. eCollection 2019 May.

Abstract

VRC01 protects macaques from vaginal SHIV infection after a single high-dose challenge. Infusion of a simianized anti-α4β7 mAb (Rh-α4β7) just prior to, and during repeated vaginal exposures to SIVmac251 partially protected macaques from vaginal SIV infection and rescued CD4+ T cells. To investigate the impact of combining VRC01 and Rh-α4β7 on SHIV infection, 3 groups of macaques were treated with a suboptimal dosing of VRC01 alone or in combination with Rh-α4β7 or with control antibodies prior to the initiation of weekly vaginal exposures to a high dose (1000 TCID50) of SHIVAD8-EO. The combination Rh-α4β7-VRC01 significantly delayed SHIVAD8-EO vaginal infection. Following infection, VRC01-Rh-α4β7-treated macaques maintained higher CD4+ T cell counts and exhibited lower rectal SIV-DNA loads compared to controls. Interestingly, VRC01-Rh-α4β7-treated macaques had fewer IL-17-producing cells in the blood and the gut during the acute phase of infection. Moreover, higher T cell responses to the V2-loop of the SHIVAD8-EO envelope in the VRC01-Rh-α4β7 group inversely correlated with set point viremia. The combination of suboptimal amounts of VRC01 and Rh-α4β7 delayed infection, altered antiviral immune responses and minimized CD4+ T cell loss. Further exploration of the effect of combining bNAbs with Rh-α4β7 on SIV/HIV infection and antiviral immune responses is warranted and may lead to novel preventive and therapeutic strategies.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology*
  • Antibodies, Monoclonal, Humanized / pharmacology*
  • Antibodies, Viral / immunology
  • Broadly Neutralizing Antibodies
  • CD4-Positive T-Lymphocytes / drug effects
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / virology
  • Drug Therapy, Combination
  • Female
  • HIV Antibodies
  • Integrins / antagonists & inhibitors*
  • Integrins / immunology
  • Macaca mulatta
  • Simian Acquired Immunodeficiency Syndrome / immunology
  • Simian Acquired Immunodeficiency Syndrome / prevention & control*
  • Simian Acquired Immunodeficiency Syndrome / virology
  • Simian Immunodeficiency Virus / drug effects*
  • Simian Immunodeficiency Virus / immunology
  • Vagina / drug effects*
  • Vagina / immunology
  • Vagina / virology
  • Viremia / immunology
  • Viremia / prevention & control*
  • Viremia / virology

Substances

  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antibodies, Viral
  • Broadly Neutralizing Antibodies
  • HIV Antibodies
  • Integrins
  • VRC01 monoclonal antibody
  • integrin alpha4beta7