Production of Extracellular Matrix-Degrading Proteases by a Rat B Cell Line.CRL-1631

Badeaux, K. Production of Extracellular Matrix-Degrading Proteases by a Rat B Cell Line.CRL-1631. Master of Science (Microbiology and Immunology), May 2002. 30 pp., 9 illustrations, 1 table, 16 bibliography titles. Previously B lymphocytes have been reported to accumulate at the site of tumor development and to play a role in immune surveillance against metastatic tumors. Investigating this mechanism, we studied B lymphocyte production of extracellular matrix-degrading proteinases: matrix metalloproteinases (MMPs) and components of the urokinase plasminogen activator (uP A) system. Our studies include RT-PCR of CRL-1631 eDNA revealing mRNA for MMP-2, MMP-9, TIMP-1, TIMP-2 and uPAR. MMP-2 and MMP-9 activity was verified by gelatin zymography. TIMP-1, TIMP-2 and uPAR protein expression was confirmed by Western blot analyses. I also report, for the first time, MT -1 MMP gene and protein expression in B cells by RT-PCR and Western blot, respectively. CRL-1631 invasion through Matrigel model basement membrane was significantly inhibited by BB-94, confirming MMP involvement in this cell line's invasiveness. Therefore, B cells use multiple proteases in the degradation of the extracellular matrix, ECM, and this may be one factor responsible for their accumulation at the site of established tumors.