A MATRIX METALLOPROTEINASE GENE EXPRESSED IN HUMAN T-LYMPHOCYTES IS IDENTICAL WITH COLLAGENASE-3 FROM BREAST CARCINOMAS

The response of human T lymphocytes to various stimuli includes the ex pression of the matrix metalloproteinase (NLMP) genes stromelysin 2, g elatinase A and gelatinase B. The proteins encoded by these genes coul d confer the capacity to degrade macromolecular components of the extr acellular matrix (ECM), and to shed transmembrane proteins such as tum or necrosis factor (TNF), TNF receptor Interleukin-6 receptor and Fas ligand. To identify further MMP genes transcribed in T lymphocytes exp osed to phorbol 12-myristate 13-acetate and a calcium ionophore, we co mbined reverse transcript-ion and polymerase chain reaction using prim ers specific for conserved domains and detected collagenase 3 transcri pts, first described in a human breast cancer. However, when the seque nce of the complementary DNA was compared, additional 23 nucleotides w ere found in the 5' nontranslated region of the lymphocyte messenger R NA (mRNA). Northern blot analysis revealed 2 major inducible mRNA spec ies of 1.9 and 2.8 kilobases, whose levels were lower than those of st romelysin 2. The observation that activated T lymphocytes transcribe s everal MMP genes, including a collagenase, indicates that the effector functions of these cells include enzymatic activities towards most co nstituents of the ECM, as well as some transmembrane proteins relevant to inflammation and apoptosis.