Increased in vitro tetanus-induced production of HIV type 1 following in vivo immunization of HIV type 1-infected individuals with tetanus toxoid

AIDS Res Hum Retroviruses. 1997 Apr 10;13(6):473-80. doi: 10.1089/aid.1997.13.473.


We have previously demonstrated that immunization of HIV-1-infected individuals with the common recall antigen, tetanus, induced transient increases in plasma viremia as well as an increased ability to isolate virus from CD8+ T cell-depleted peripheral blood mononuclear cells (PBMCs) under minimally stimulated culture conditions (IL-2 plus IL-4) postimmunization. In this study, HIV-1-infected individuals were immunized with tetanus toxoid and PBMCs were examined at multiple time points following immunization. Tetanus-induced production of virus was defined as an increased ability to isolate HIV-1 from CD8+ T cell-depleted PBMCs in vitro in the presence of tetanus antigen as opposed to no antigen or control antigen alone. Following immunization, in vitro tetanus-induced production of HIV-1 was observed in 8 of 13 (62%) patients compared to 2 of 13 (15%) patients prior to immunization. In four of these patients, virus could also be isolated from CD8+ T cell-depleted PBMCs in the presence of tetanus without the addition of any exogenous IL-2. Furthermore, virus could be isolated from the unfractionated PBMCs of two patients when tetanus antigen alone was added to the culture in the absence of added PHA or PHA blasts. HIV-1 was isolated predominantly from CD4+ T cells with a CD45RO+, CD25+ phenotype and was associated with a trend to elevated levels in culture supernatants of IFN-gamma, IL-6, TNF-alpha, and IL-4. These findings have important implications with regard to the role of ongoing antigen-specific immune responses in the induction of HIV-1 expression in vivo.

MeSH terms

  • HIV Infections / blood
  • HIV Infections / immunology*
  • HIV Infections / virology
  • HIV-1 / growth & development*
  • Humans
  • Immunization
  • Tetanus Toxoid / immunology*


  • Tetanus Toxoid