Integrated morphogen signal inputs in gammadelta versus alphabeta T-cell differentiation.
Morphogens, a class of secreted proteins that regulate gene expression in a concentration-dependent manner, are responsible for directing nearly all lineage fate choices during embryogenesis. In the thymus, morphogen signal pathways consisting of WNT, Hedgehog, and the transforming growth factor-beta superfamily are active and have been implicated in various developmental processes including proliferation, survival, and differentiation of maturing thymocytes. Intriguingly, it has been inferred that some of these morphogen signal pathways differentially affect gammadelta and alphabeta T-cell development or maintenance, but their role in T-cell lineage commitment has not been directly probed. We have recently identified a modulator of morphogen signaling that significantly influences binary gammadelta versus alphabeta T-cell lineage diversification. In this review, we summarize functions of morphogens in the thymus and provide a highly speculative model of integrated morphogen signals, potentially directing the gammadelta versus alphabeta T-cell fate determination process.
Melichar
Heather
H
Department of Pathology University of Massachusetts Medical School, Worcester, MA 01655, USA.
Kang
Joonsoo
J
D000818:Animals; D002454:Cell Differentiation / Q000276:immunology*; D019070:Cell Lineage / Q000276:immunology; D005786:Gene Expression Regulation; D053823:Hedgehog Proteins / Q000276:immunology; D006801:Humans; D018448:Models, Immunological; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology*; D013950:Thymus Gland / Q000196:embryology / Q000276:immunology; D015291:Transforming Growth Factors / Q000276:immunology; D051153:Wnt Proteins / Q000276:immunology
D053823:Hedgehog Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D051153:Wnt Proteins; D015291:Transforming Growth Factors