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Type I interferon supports primary CD8 + T‐cell responses to peptide‐pulsed dendritic cells in the absence of CD4 + T‐cell help
Author(s) -
Ontiveros Fernando,
Wilson Elizabeth B.,
Livingstone Alexandra M.
Publication year - 2011
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2010.03400.x
Subject(s) - cytotoxic t cell , cd8 , t cell , antigen presenting cell , biology , antigen , dendritic cell , immunology , interleukin 21 , cytokine , microbiology and biotechnology , immune system , biochemistry , in vitro
Summary CD8 + T‐cell responses to non‐pathogen, cell‐associated antigens such as minor alloantigens or peptide‐pulsed dendritic cells (DC) are usually strongly dependent on help from CD4 + T cells. However, some studies have described help‐independent primary CD8 + T‐cell responses to cell‐associated antigens, using immunization strategies likely to trigger natural killer (NK) cell activation and inflammatory cytokine production. We asked whether NK cell activation by MHC I‐deficient cells, or administration of inflammatory cytokines, could support CD4 + T‐cell help‐independent primary responses to peptide‐pulsed DC. Injection of MHC I‐deficient cells cross‐primed CD8 + T‐cell responses to the protein antigen ovalbumin (OVA) and the male antigen HY, but did not stimulate CD8 + T‐cell responses in CD4‐depleted mice; hence NK cell stimulation by MHC I‐deficient cells did not replace CD4 + T‐cell help in our experiments. Dendritic cells cultured with tumour necrosis factor‐α (TNF‐α) or type I interferon‐α (IFN‐α) also failed to prime CD8 + T‐cell responses in the absence of help. Injection of TNF‐α increased lymph node cellularity, but did not generate help‐independent CD8 + T‐cell responses. In contrast, CD4‐depleted mice injected with IFN‐α made substantial primary CD8 + T‐cell responses to peptide‐pulsed DC. Mice deficient for the type I IFN receptor (IFNR1) made CD8 + T‐cell responses to IFNR1‐deficient, peptide‐pulsed DC; hence IFN‐α does not appear to be a downstream mediator of CD4 + T‐cell help. We suggest that primary CD8 + T‐cell responses will become help‐independent whenever endogenous IFN‐α secretion is stimulated by tissue damage, infection, or autoimmune disease.