Cutting edge: developmental switches in chemokine responses during T cell maturation

JJ Campbell, J Pan, EC Butcher - The Journal of Immunology, 1999 - journals.aai.org
JJ Campbell, J Pan, EC Butcher
The Journal of Immunology, 1999journals.aai.org
We show that developmental transitions during thymocyte maturation are associated with
dramatic changes in chemotactic responses to chemokines. Macrophage-derived
chemokine, a chemokine expressed in the thymic medulla, attracts thymocytes only during a
brief window of development, between the late cortical and early medullary stages. All
medullary phenotypes (CD4 or CD8 single positive) but not immature thymocytes respond to
the medullary stroma-expressed (and secondary lymphoid tissue-associated) chemokines …
Abstract
We show that developmental transitions during thymocyte maturation are associated with dramatic changes in chemotactic responses to chemokines. Macrophage-derived chemokine, a chemokine expressed in the thymic medulla, attracts thymocytes only during a brief window of development, between the late cortical and early medullary stages. All medullary phenotypes (CD4 or CD8 single positive) but not immature thymocytes respond to the medullary stroma-expressed (and secondary lymphoid tissue-associated) chemokines secondary lymphoid-tissue chemokine and macrophage inflammatory protein-3β. The appearance of these responses is associated with the phenotypic stage of cortex to medulla migration and with up-regulation of mRNA for the receptors CCR4 (for macrophage-derived chemokine and thymus and activation-regulated chemokine) and CCR7 (for secondary lymphoid-tissue chemokine and macrophage inflammatory protein-3β). In contrast, most immature and medullary thymocytes migrate to thymus-expressed chemokine, an ability that is lost only with up-regulation of the peripheral homing receptor L-selectin during the latest stages of thymocyte maturation associated with export to the periphery. Developmental switches in chemokine responses may help regulate critical migratory events during T cell development.
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