title: In vitro analysis of verapamil-induced immunosuppression: potent inhibition of T cell motility and lymphocytic transmigration through allogeneic endothelial cells.
abstract: BACKGROUND
  Cyclosporine A (CsA) and tacrolimus prevent proliferation but not transendothelial migration of alloreactive lymphocytes into donor organs. As a result, serious adverse effects, such as nephrotoxicity and neurotoxicity, have been observed under CsA/tacrolimus therapy. The incorporation of new drugs with infiltration blocking properties might enhance the efficacy of the current immunosuppressive protocol, allowing lower CsA/tacrolimus dosage. Because Ca2+ plays a critical role in cell-cell interaction, the Ca2+-channel blocker verapamil might be a good cany. didate for supporting CsA/tacrolimus-based therapy.
  
  
  METHODS
  A T-cell endothelial cell coculture model or immobilized immunoglobulin G globulin chimeras were employed to investigate how S- and R- verapamil interfere with the lymphocytic infiltration process. The expression and arrangement of membranous adhesion receptors and cytoskeletal F-actin filaments were analyzed by fluorometric method in the presence of. verapamil.
  
  
  RESULTS
  Both verapamil enantiomers strongly inhibited lymphocyte infiltration. CD4+ and CD8+ T-cells were influenced to a similar extent with regard to horizontal locomotion (CD4+=CD8+), but to a different extent with regard to adhesion and penetration (CD4+ > CD8+). Moreover, penetration was blocked to a higher extent than was adhesion. ID50-values were 31 microM (CD4+-adhesion) and 11 microM (CD4+-penetration). Verapamil reduced P-selectin expression on endothelial cells and effectively down-regulated binding of T-cells to immobilized P-selectin immunoglobulin G globulins (ID50=4.4 microM; CD4+). A verapamil-induced reduction of intracellular F-actin in T-lymphocytes was proven to be mainly responsible for diminished cell locomotion.
  
  
  CONCLUSIONS
  The prevention of CD4+ T-cell penetration by verapamil might argue for its use as an adjunct to CsA/tacrolimus-based immunosuppressive therapy.
authors.affiliation: Department of General Surgery, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. Blaheta@em.uni-frankfurt.de
authors.forename: R A
authors.initials: RA
authors.lastname: Blaheta
authors.forename: N P
authors.initials: NP
authors.lastname: Hailer
authors.forename: N
authors.initials: N
authors.lastname: Brude
authors.forename: B
authors.initials: B
authors.lastname: Wittig
authors.forename: K
authors.initials: K
authors.lastname: Leckel
authors.forename: E
authors.initials: E
authors.lastname: Oppermann
authors.forename: M
authors.initials: M
authors.lastname: Bachmann
authors.forename: S
authors.initials: S
authors.lastname: Harder
authors.forename: J
authors.initials: J
authors.lastname: Cinatl
authors.forename: M
authors.initials: M
authors.lastname: Scholz
authors.forename: J
authors.initials: J
authors.lastname: Bereiter-Hahn
authors.forename: S
authors.initials: S
authors.lastname: Weber
authors.forename: A
authors.initials: A
authors.lastname: Encke
authors.forename: B H
authors.initials: BH
authors.lastname: Markus
mesh_terms: D002465:Cell Movement / Q000187:drug effects; D015232:Dinoprostone / Q000494:pharmacology; D019040:E-Selectin / Q000096:biosynthesis / Q000187:drug effects; D004730:Endothelium, Vascular / Q000166:cytology; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects*; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects; D016256:Lewis X Antigen / Q000378:metabolism; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D019007:P-Selectin / Q000096:biosynthesis / Q000187:drug effects; D011485:Protein Binding; D013601:T-Lymphocytes / Q000166:cytology; D019010:Vascular Cell Adhesion Molecule-1 / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology* / Q000633:toxicity
chemical_list: D019040:E-Selectin; D016256:Lewis X Antigen; D016169:Lymphocyte Function-Associated Antigen-1; D019007:P-Selectin; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D014700:Verapamil; D015232:Dinoprostone