Murine T cell activation is regulated by surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide).

•Surfen is the first inhibitor of glycosaminoglycan function to be studied in murine T cells.•Surfen reduces T cell proliferation stimulated in vitro and in vivo.•Surfen reduces CD25 expression in T cells activated in vivo but not in vitro.•Surfen increases T cell proliferation when T cell receptor activation is bypassed.•Surfen’s effects are blocked by co-administration of heparin sulfate.