Demonstration of granzyme A and perforin messenger RNA in the synovium of patients with rheumatoid arthritis.
OBJECTIVE
To examine the gene expression of 2 highly specific markers of cytotoxic T lymphocyte (CTL) activation, the serine protease granzyme A and the pore-forming protein perforin, in synovial tissue of patients with rheumatoid arthritis (RA), and to compare the findings with those in osteoarthritis (OA) synovial tissue.


METHODS
Snap-frozen synovial tissue specimens from 9 patients with RA and 5 patients with OA were examined. The number of CTL that expressed granzyme A or perforin messenger RNA was determined by in situ hybridization using nonradioactive riboprobes for granzyme A and perforin, and by a novel in situ reverse transcriptase technique. The signals were visualized by an immunogold-silver immunohistochemistry technique and compared with immunohistochemical labeling of T and B cells. Additional double-labeling was achieved using anti-type IV collagen, anti-macrophage (anti-CD68), anti-T lymphocyte (anti-CD45RO), anti-B lymphocyte (anti-CD20), and anti-natural killer cell (anti-CD56) antibodies in an alkaline phosphatase-anti-alkaline phosphatase assay.


RESULTS
Granzyme A and perforin messenger RNA (mRNA) was observed in CTL in synovial specimens from all of the RA patients, whereas in specimens from OA patients only a few, single cells with a positive mRNA signal for these molecules could be detected. In the RA specimens, the number of lymphocytes showing a positive mRNA signal for granzyme A or perforin varied from 10% to 50%, reflecting the recent findings of other investigators studying synovial fluid.


CONCLUSIONS
Our results demonstrate that gene expression of at least 2 CTL products, granzyme A and perforin, is up-regulated in the synovium of patients with RA compared with that in the synovium of patients with OA. These molecules presumably play an important role not only in lymphocyte-mediated cytotoxicity, but also in facilitating the migration of blood-borne mononuclear cells through the vascular basement membrane into the rheumatoid synovium.
Müller-Ladner
U
U
Department of Medicine, University of Alabama at Birmingham, 35294-0006, USA.
Kriegsmann
J
J
Tschopp
J
J
Gay
R E
RE
Gay
S
S
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D053804:Granzymes; D006801:Humans; D007150:Immunohistochemistry; D017493:Leukocyte Common Antigens / Q000032:analysis; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D010003:Osteoarthritis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000235:genetics*; D013583:Synovial Membrane / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism
D015703:Antigens, CD; D018951:Antigens, CD20; D000944:Antigens, Differentiation, B-Lymphocyte; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D012333:RNA, Messenger; D054353:Perforin; D017493:Leukocyte Common Antigens; D053804:Granzymes; D012697:Serine Endopeptidases; C509212:GZMA protein, human