Interferon gamma secreted by?
High-Yield Explanation
ANSWER: (A) CD4 T cellREF: Jawett s 24th edition section IV. Virology > Chapter 30. Pathogenesis & Control of Viral Diseases > Table 30-7See APPENDIX-19 for list of "CYTOKINES"Synthesis of InterferonsInterferons are produced by all vertebrate species. Normal cells do not generally synthesize interferon until they are induced to do so. Infection with viruses is a potent insult leading to induction; RNA viruses are stronger inducers of interferon than DNA viruses. Interferons also can be induced by double-stranded RNA, bacterial endotoxin, and small molecules such as tilorone. IFN-g is not produced in response to most viruses but is induced by mitogen stimulation.The different classes of interferon are produced by different cell types. IFN-a and IFN-b are synthesized by many cell types, but IFN-g is produced mainly by lymphocytes, especially T cells and natural killer (NK) cells. Dendritic cells are potent interferon producers; under the same virus challenge conditions, dendritic cells can secrete up to l000x more interferon than fibroblasts. APPENDIX -19Cytokines:NameMajor Cellular SourceSelected Biologic EffectsIFN-a,bMacrophages (IFNa)fibroblasts (IFNb)AntiviralIFN-gCD4+- T cells, NK cellsActivates macrophages, TH1 differentiationTNF-aMacrophages, T cellsCell activation, Fever, cachexia, antitumorTNF-a, LT (lymphotoxin)T cellsActivates PMNsIL-1MacrophagesCell activation, Fever (Pro inflammatory)IL-2T cellsT cell growth and activationIL-3T cellsHematopoiesisIL-4T cells, mast cellsB cell proliferation and switching to IgE, TH2 differentiationIL-5T cellsDifferentiation of eosinophil, activates B cellsIL-7Bone marrow stroma cellsT cell progenitor differentiationIL-8Macrophages, T cellsChemotactic for neutrophilsIL-10Macrophages, T cellsInhibits activated macrophages and dendritic cells, Anti-inflammatoryIL-12MacrophagesDifferentiation of T cells, activation of NK cellsGM-CSFT cells, macrophages, monocytesDifferentiation of myeloid progenitor cellsM-CSFMacrophages, monocytes, fibroblastsDifferentiation of monocytes and macrophagesG-CSFFibroblasts, monocytes, macrophagesStimulates neutrophil production in bone marrow