A Th17-like developmental process leads to CD8(+) Tc17 cells with reduced cytotoxic activity.
Activation of naive CD8(+) T cells with antigen in the absence of skewing cytokines triggers their differentiation into effector CTL, which induces death of target cells. We show that CD8(+) T cells activated in the presence of the cytokines IL-6 or IL-21 plus TGF-beta similar to CD4(+) T cells, develop into IL-17-producing (Tc17) cells. These cells display greatly suppressed cytotoxic function along with low levels of the CTL markers: T-box transcription factor Eomesodermin, granzyme B and IFN-gamma. Instead, these cells express hallmark molecules of Th17 program including retinoic acid receptor-related orphan receptor (ROR)gammat, RORalpha, IL-21 and IL-23R. The expression of the type 17 master regulator RORgammat is causally linked to Tc17 generation, because its overexpression stimulates production of IL-17 in the presence of IL-6 or IL-21. Both, upregulation of the type 17 program as well as suppression of CTL differentiation are STAT3 dependent. Furthermore, Tc17 cells producing IL-17 but not granzyme B are also detectable in EAE, a mouse model for multiple sclerosis. Our data point to the existence of mutually exclusive CTL and Tc17 developmental pathways in vitro and in vivo.
Huber
Magdalena
M
Institute for Medical Microbiology and Hygiene, University of Marburg, Germany. huberma@med.uni-marburg.de
Heink
Sylvia
S
Grothe
Henrike
H
Guralnik
Anna
A
Reinhard
Katharina
K
Elflein
Karin
K
Hünig
Thomas
T
Mittrücker
Hans-Willi
HW
Brüstle
Anne
A
Kamradt
Thomas
T
Lohoff
Michael
M
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects; D053804:Granzymes / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D007371:Interferon-gamma / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism*; D015850:Interleukin-6 / Q000494:pharmacology; D007378:Interleukins / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D000098546:Interleukin-21
D020381:Interleukin-17; D015850:Interleukin-6; D007378:Interleukins; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; C539901:Rorc protein, mouse; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D016212:Transforming Growth Factor beta; D049452:Green Fluorescent Proteins; D007371:Interferon-gamma; D053804:Granzymes; D000098546:Interleukin-21