ICOS-mediated signaling regulates cytokine production by human T cells and provides a unique signal to selectively control the clonal expansion of Th2 helper cells.
The CD28 homologue inducible costimulator (ICOS) has been demonstrated to regulate a number of T cell-dependent immune responses in vivo. However, the expression and functional importance of ICOS during APC-Th cell interaction in the human is not fully understood. Here, we demonstrate that ICOS-mediated signaling plays an important role in the production of selective cytokines during both primary and subsequent Th cell responses upon allospecific or superantigen activation. In contrast, ICOS does not play a role in the differentiation of naive cells into Th1 or Th2 effector cells, nor does it determine the type of effector function of memory cells upon subsequent allogeneic challenge. In addition, our data demonstrate that ICOS provides a novel and unique role in regulating DC-mediated Th2, but not Th1 cell clonal expansion. These data suggest that ICOS-mediated signaling plays a discrete role in the regulation of human T helper cell responses.
Vieira
Pedro L
PL
Academic Medical Center, Department of Cell Biology and Histology, University of Amsterdam, Amsterdam, The Netherlands. pvieira@nimr.mrc.ac.uk
Wassink
Lianne
L
Smith
L Mary
LM
Nam
Samuel
S
Kingsbury
Gillian A
GA
Gutierrez-Ramos
Jose Carlos
JC
Coyle
Anthony J
AJ
Kapsenberg
Martien L
ML
Wierenga
Eddy A
EA
D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D018122:B7-1 Antigen / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D016207:Cytokines / Q000096:biosynthesis*; D006801:Humans; D060945:Inducible T-Cell Co-Stimulator Ligand; D060889:Inducible T-Cell Co-Stimulator Protein; D015398:Signal Transduction / Q000502:physiology*; D018418:Th2 Cells / Q000378:metabolism*; D015854:Up-Regulation
D000945:Antigens, Differentiation, T-Lymphocyte; D018122:B7-1 Antigen; D016207:Cytokines; C556692:ICOS protein, human; D060945:Inducible T-Cell Co-Stimulator Ligand; D060889:Inducible T-Cell Co-Stimulator Protein