Ovalbumin injected with complete Freund's adjuvant stimulates cytolytic responses

Academic Article


  • CD8+ cytotoxic T lymphocytes (CTL) recognize antigens (Ag) associated with class I major histocompatibility complex (MHC) molecules. Endogenously synthesized protein Ag are processed into peptides in the cytoplasm and transported to the endoplasmic reticulum where they are bound by class I proteins. Exogenous Ag do not enter the class I processing pathway of most cells and thus do not activate CD8+ CTL. Nevertheless, several investigators have reported that immunization with exogenous Ag can activate CD8+ T cells that have immunoregulatory activity. To determine how exogenous Ag entered the class I pathway in vivo and whether immunosuppressive CD8+ T cells were cytolytic, we have shown in this report that injection with OVA emulsified in the complete Freund's adjuvant (CFA) primed CD8+, class I MHC‐restricted, OVA‐specific CTL in mice. These CTL recognize the OVA257–264 epitope, produce tumor necrosis factor‐α and interferon‐γ upon activation. Both oil and mycobacteria components in CFA were required for inducing CTL responses. Priming was not attributed to direct sensitization of class I‐bearing cells by contaminating peptides. Rather, phagocytic cells, but not CD4+ helper T cells, were required for priming CD8+ CTL by OVA‐CFA. Thus, OVA in CFA is taken up by antigen‐presenting cells and processed into the class I pathway by phagocytic cells in vivo. In addition, CTL induced by OVA‐CFA suppressed the antibody response to OVA in adoptive recipients. These results suggest that CD8+ CTL specific for exogenous proteins might be routinely stimulated by injecting proteins in conventional adjuvants and that such cells have the potential to regulate immune responses in vivo. Copyright © 1995 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
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    Digital Object Identifier (doi)

    Author List

  • Ke Y; Li Y; Kapp JA
  • Start Page

  • 549
  • End Page

  • 553
  • Volume

  • 25
  • Issue

  • 2