Early stages in human and mouse T-cell development.
One important question in lymphopoiesis is where stem cells commit to T-, B- and natural killer (NK)-cell lineages. Recent findings in human and mouse systems suggest that the thymus is seeded by a yet uncommitted progenitor cell. The earliest murine thymic progenitor cells have the capacity to develop into B, T and NK cells when introduced into the appropriate microenvironment. The mechanisms underlying T-cell commitment are unknown, but cytokines might be involved. The gamma-chain of the interleukin (IL)-2 receptor seems to play a role in development of T and NK cells, but the current data argue against a critical role for IL-2 in T- and NK-cell development. This suggests that the IL-2 receptor gamma-chain is part of a receptor for another cytokine, important for T- and NK-cell development. IL-7 might be involved in regulating T-cell receptor rearrangements and in proliferation of cells within the thymus.
Spits
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Division of Immunology, The Netherlands Cancer Institute, Amsterdam.
D000818:Animals; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D016207:Cytokines / Q000502:physiology; D006801:Humans; D007107:Immune System / Q000166:cytology* / Q000196:embryology; D007376:Interleukin-2 / Q000502:physiology; D007694:Killer Cells, Natural / Q000502:physiology*; D008099:Liver / Q000166:cytology / Q000196:embryology; D051379:Mice; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology
D016207:Cytokines; D007376:Interleukin-2; D016693:Receptors, Antigen, T-Cell, alpha-beta