Dendritic cells mediate NK cell help for Th1 and CTL responses: two-signal requirement for the induction of NK cell helper function.
Early stages of viral infections are associated with local recruitment and activation of dendritic cells (DC) and NK cells. Although activated DC and NK cells are known to support each other's functions, it is less clear whether their local interaction in infected tissues can modulate the subsequent ability of migrating DC to induce T cell responses in draining lymph nodes. In this study, we report that NK cells are capable of inducing stable type 1-polarized "effector/memory" DC (DC1) that act as carriers of NK cell-derived helper signals for the development of type 1 immune responses. NK cell-induced DC1 show a strongly elevated ability to produce IL-12p70 after subsequent CD40 ligand stimulation. NK-induced DC1 prime naive CD4+ Th cells for high levels of IFN-gamma, but low IL-4 production, and demonstrate a strongly enhanced ability to induce Ag-specific CD8+ T cell responses. Resting NK cells display stringent activation requirements to perform this novel, DC-mediated, "helper" function. Although their interaction with K562 cells results in effective target cell killing, the induction of DC1 requires a second NK cell-activating signal. Such costimulatory signal can be provided by type I IFNs, common mediators of antiviral responses. Therefore, in addition to their cytolytic function, NK cells also have immunoregulatory activity, induced under more stringent conditions. The currently demonstrated helper activity of NK cells may support the development of Th1- and CTL-dominated type 1 immunity against intracellular pathogens and may have implications for cancer immunotherapy.
Mailliard
Robbie B
RB
Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Son
Young-Ik
YI
Redlinger
Richard
R
Coates
Patrick T
PT
Giermasz
Adam
A
Morel
Penelope A
PA
Storkus
Walter J
WJ
Kalinski
Pawel
P
D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D002450:Cell Communication / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D017874:Immediate-Early Proteins / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000096:biosynthesis; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D021122:Protein Subunits / Q000096:biosynthesis; D015398:Signal Transduction / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D015534:Trans-Activators / Q000276:immunology; D014764:Viral Proteins
C068382:BRLF1 protein, Human herpesvirus 4; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D017874:Immediate-Early Proteins; D021122:Protein Subunits; D015534:Trans-Activators; D014764:Viral Proteins; D018664:Interleukin-12; D007371:Interferon-gamma