Intravital demonstration of modulation of T lymphocyte migration by CINC/gro in rat Peyer's patches

Background/Aims: Cytokine-induced neutrophil chemoattractant (CINC/gro), a member of interleukin-8 family, was found as a potent chemotactic factor fo r rat neutrophils. Although several chemokines have been shown to be potent regulators of T cell chemotaxis in vitro, the potential role of chemokines in T-cell migration in gut-associated lymphoid tissues has not been invest igated in vivo. in the present study, the effects of CINC/gro on T-lymphocy te migration were examined in rat Peyer's patches. Methods: T lymphocytes c ollected from intestinal lymph of rats were fluorescence-labeled and inject ed into the jugular vein. Peyer's patches of the recipient rats were observ ed with intravital fluorescence microscopy and the effects of CINC/gro infu sion was investigated. Lymphocyte flux in mesenteric collecting lymphatics was also observed. Results: In vivo infusion of CINC/gro significantly atte nuated the initial lymphocyte interaction with postcapillary venules of Pey er's patches. However, once these lymphocytes adhered to venules, CINC/gro treatment significantly accelerated the transendothelial migration of T lym phocytes and they also significantly increased their subsequent flux in col lecting lymphatics. Conclusion: There is a possibility that CINC/gro could modulate the characteristics of T lymphocyte homing in the inflammatory sit es of gut. Copyright (C) 2001 S. Karger AG, Basel.