Failed CTL/NK cell killing and cytokine hypersecretion are directly linked through prolonged synapse time.
Failure of cytotoxic T lymphocytes (CTLs) or natural killer (NK) cells to kill target cells by perforin (Prf)/granzyme (Gzm)-induced apoptosis causes severe immune dysregulation. In familial hemophagocytic lymphohistiocytosis, Prf-deficient infants suffer a fatal "cytokine storm" resulting from macrophage overactivation, but the link to failed target cell death is not understood. We show that prolonged target cell survival greatly amplifies the quanta of inflammatory cytokines secreted by CTLs/NK cells and that interferon-γ (IFN-γ) directly invokes the activation and secondary overproduction of proinflammatory IL-6 from naive macrophages. Furthermore, using live cell microscopy to visualize hundreds of synapses formed between wild-type, Prf-null, or GzmA/B-null CTLs/NK cells and their targets in real time, we show that hypersecretion of IL-2, TNF, IFN-γ, and various chemokines is linked to failed disengagement of Prf- or Gzm-deficient lymphocytes from their targets, with mean synapse time increased fivefold, from ∼8 to >40 min. Surprisingly, the signal for detachment arose from the dying target cell and was caspase dependent, as delaying target cell death with various forms of caspase blockade also prevented their disengagement from fully competent CTLs/NK cells and caused cytokine hypersecretion. Our findings provide the cellular mechanism through which failed killing by lymphocytes causes systemic inflammation involving recruitment and activation of myeloid cells.
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia misty.jenkins@petermac.org joe.trapani@petermac.org.
Misty R
MR
Jenkins
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia.
Jesse A
JA
Rudd-Schmidt
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia.
Jamie A
JA
Lopez
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia.
Kelly M
KM
Ramsbottom
The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia Immunology and Diabetes Unit, St. Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia.
Stuart I
SI
Mannering
The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia.
Daniel M
DM
Andrews
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia.
Ilia
I
Voskoboinik
Cancer Cell Death and Killer Cell Biology Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia The Sir Peter MacCallum Department of Oncology; Department of Genetics; and Department of Medicine, St. Vincent's Hospital; The University of Melbourne, Parkville, Victoria 3010, Australia misty.jenkins@petermac.org joe.trapani@petermac.org.
Joseph A
JA
Trapani
D000818:Animals; D020013:Calcium Signaling; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D053804:Granzymes / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D007694:Killer Cells, Natural / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D054353:Perforin / Q000235:genetics / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*; D013997:Time Factors
D016207:Cytokines; D015850:Interleukin-6; D054353:Perforin; D007371:Interferon-gamma; D053804:Granzymes; D020169:Caspases