Growth factors have been implicated in thymocyte development, but mutants lacking cytokines, or their receptors, have failed to reveal essential roles for growth/differentiation factors in the thymus. Mutations in the receptor tyrosine kinase c-kit and the common cytokine receptor γ chain (γ(c)) reduce cellularity, but are permissive for thymocyte development. We now report that thymocyte development is completely abrogated in mice lacking both c-kit and γ(c) (c-kit-γ(c)-). Thymic hypocellularity is so severe that the T cell receptor repertoire fails to form except for monoclonal or oligoclonal β chain DJ rearrangements. B lymphopoiesis is only mildly reduced in c-kit-γ(c)- as compared with c-kit+γ(c)- mice, and hematological values are identical comparing c-kit-deficient and c-kit-γ(c)- mice. These experiments reveal essential, overlapping, and synergistic functions for two distinct signaling pathways, one utilizing c-kit and the other cytokine receptor γ(c) complexes coupling to Janus kinases and signal transducers and activators of transcription.
Rodewald, H. R., Ogawa, M., Haller, C., Waskow, C., & DiSanto, J. P. (1997). Pro-thymocyte expansion by c-kit and the common cytokine receptor γ chain is essential for repertoire formation. Immunity, 6(3), 265–272. https://doi.org/10.1016/S1074-7613(00)80329-5