Abstract: An immunosuppressive drug, an autoimmune disease treating drug, an immunosuppression enhancing drug and a cell adhesion inhibitor, each containing a thienotriazolodiazepine compound wherein the 2-position of its diazepine ring is alkylated as an active ingredient, an immunosuppression method, an autoimmune disease treating method, an immunosuppression enhancing method and a cell adhesion inhibiting method, each of which comprising administering the compound, and uses of the compound for the production of an immunosuppressive drug, an autoimmune disease treating drug, an immunosuppression enhancing drug and a cell adhesion inhibitor.

Abstract: The present invention relates to an immunosuppressive agent which comprises at least one compound selected from the compounds of formula ##STR1## wherein R represents a hydrogen atom or an acyl, Y represents carbonyl or hydroxymethylene and represents a single bond or a double bond and their lactones, in an effective amount and a pharmaceutically acceptable carrier; a method of prophylaxis and therapy for suppressing rejection or autoimmune diseases which comprises administering the above-mentioned compound or its lactone in an effective amount; and a novel compound of formula ##STR2## or its lactone.

Abstract: A new immunosuppressive factor derived from human T cell leukemia cells characterized by the following properties:(1) molecular weight: 45,000 to 65,000 daltons and 150,000 to 200,000 daltons by gel filtration, and approximately 31,000 daltons by SDS-polyacrylamide gel electrophoresis;(2) isoelectric point: 4.6 to 4.8;(3) being elutable at a concentration of 0.31 to 0.32 M sodium chloride by FPLC-Mono Q anion exchange chromatography;(4) not adsorbable to immobilized concanavalin A Sepharose or blue Sepharose;(5) resistant to deoxyribonuclease, ribonuclease, papin and periodic acid but sensititive to trypsin, .alpha.-chymotrypsin or pronase;(6) stable at pH 2 to 10;(7) stable for a long time at 4.degree. C. but partially inactivated by heat treatment at 56.degree. C. or 90.degree. C. for 30 minutes;(8) not inhibitable by 2-mercaptoethanol, levamisole, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, .alpha.