Alterations in macrophage collagenase secretion induced by gold sodium thiomalate.

The effects of gold sodium thiomalate (GST) on the production of specific collagenase by thioglycolate-elicited macrophages was investigated. Our studies demonstrated that GST administration can significantly decrease collagenase production in a dose-dependent manner. These effects were observed with levels of GST attainable in serum or synovial tissue during routine chrysotherapy. In addition, GST altered lysozyme secretion by activated macrophages in a pattern distinct from that of collagenase alteration. These effects of enzyme secretion were not secondary effects of GST on viability, general protein secretion, or the specific assay procedures utilized, and were not attributable to the thiomalate moiety. Thus, GST may exert its therapeutic effect in rheumatoid arthritis through interference with the production of degradative proteolytic enzymes, which are important effector molecules mediating tissue destruction.

Isolation, characterization, and amino-terminal amino acid sequence analysis of human neutrophil elastase from normal donors.

Human neutrophil elastase from normal donors has been purified using an isolation procedure which included sequential sodium chloride extraction, Aprotinin-Sepharose affinity chromatography, CM-cellulose ion-exchange chromatography, and AcA44 gel filtration chromatography. The inclusion of this last purification step was crucial for separating inactive lower molecular weight species from the active forms of neutrophil elastase and resulted in a higher specific activity of the final preparation. Sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis of the reduced purified protein demonstrated three polypeptides of Mr 31,000, 28,000, and 27,500. Four polypeptides were resolved on acid gel electrophoresis; each of the four possessed amidolytic activity. Furthermore, peptide analysis of Staphylococcus aureus V8 protease digests indicated that these polypeptides are structurally related to each other and represent microheterogeneity of the purified protein. The apparent isoelectric points of these four forms as determined by two-dimensional electrophoresis range from 6.1 to 6.7. By utilizing microsequencing techniques, the first 40 residues of neutrophil elastase have been determined and compared with the reported sequence of elastase isolated from leukemic myeloid cells. In addition, a high degree of homology was found within the amino-terminal regions of neutrophil elastase and the serine proteinases porcine elastase, bovine chymotrypsin, human factor D, and the beta chain of plasmin.

Local synthesis of IgM and IgM rheumatoid factor in rheumatoid pleuritis.

Pleura from 3 patients with rheumatoid pleuritis and from 5 patients with other diseases was examined for its capacity to synthesize IgM and IgM rheumatoid factor (RF). IgM was synthesized by pleura from all 3 patients with rheumatoid pleuritis and IgM RF by 2. Pleura from each of the control patients synthesized less than or equal to 1 ng/mg of IgM and IgM RF. Moreover, pleura from a 4th patient with rheumatoid pleuritis incorporated 3H-leucine into newly synthesized IgM. Simultaneously obtained pleural fluid mononuclear cells (MNL) and pleural tissue from a patient with rheumatoid pleuritis synthesized identical proportions of IgM and IgM RF whereas IgM RF production was not observed with peripheral blood MNL from the same patient. The results support the view that local production of IgM and IgM RF occurs in rheumatoid pleuritis and suggest that local immune events contribute to the pathogenesis of this disorder.