New monoclonal antibodies directed against human renin. Powerful tools for the investigation of the renin system.

Abstract

A bstract. Monoclonal antibodies directed against human renin were obtained by the fusing of myeloma cells with spleen cells from Balb/c or highresponder Biozzi mice injected with pure tumoral or highly purified renal renin. These procedures resulted in the production of seven stable monoclonal antibodies to human renin. Antibodies in the hybridoma culture medium were screened by binding to pure iodinated renin or insolubilized renin in a solid phase assay. The concentration of purified antibodies that provided a 50% binding to iodinated renin varied from 1 X 10-10 to 1 X 10-7 M. Two monoclonal antibodies were found to be potent inhibitors of renin enzymatic activity in vitro, behaving as noncompetitive inhibitors (Ki, 1 to 4 X 10`s M). They were specific for primate renin. Three monoclonal antibodies provided suitable immunoadsorbants for renin purification. One of these immunoadsorbants was used for large-scale purification of the renal enzyme, resulting in an 825-fold renin enrichment in a single step. Two antibodies were able to distinguish between active and inactive renin and enabled concomitant separation and purification of the two enzyme forms in various biological fluids. Monoclonal antibodies also stained human and monkey renal renin when indirect immunofluorescence and peroxidase-antiperoxidase techniques were used. A highly sensitive radioimDr. Atlas is with the

Comparison of immunoreactive renin and plasma renin activity in human plasma.

“…With this polyclonal antibody it was impossible to distinguish the active form of renin from the inactive form which constitutes approximately 70% of total renin in human plasma (Tsunoda et al 1986). On the other hand, the monoclonal antirenin antibody, developed by Corbol and colleagues (Galen et al 1984) and used in the present study, has an excellent specificity for active renin. This antibody may make a direct radioimmunoassay possible and applicable in significant clinical situations.…”

“…The measurement of PRC employed a direct RIA kit (Galen et al 1984; Renin RIA Pasteur Kit, Diagnostic Pasteur Co., Ltd., Paris, France). To 250,1 of sample plasma or standard solution, 250 ,u 1 of a suspension containing the first antihuman renin monoclonal antibody coupled with magnetic particles was added and incubated for 2 hr at roomtemperature.…”

“…leagues have developed a new direct RIA for plasma renin concentration (PRC), using a monoclonal antibody which recognizes only active renin in human plasma (Galen et al 1984). In the present study, this new direct RIA for PRC was compared with the measurement of plasma renin activity (PRA), the conventional method for estimating plasma renin level (Haber et al 1969; Abe et al 1975).…”

Regulation of Aminopeptidase A in Human Brain Tumor Vasculature: Evidence for a Role of Transforming Growth Factor-β

“…1, A and B), some astrocytes, and resident macrophages/ microglia (not shown). The specificity of the immunoreactivity for renin was ascertained by using as a negative control the monoclonal antibody 4G1, which recognizes only soluble forms of renin (Galen et al, 1984). This antibody did not recognize any structure in our conditions (not shown).…”

“…Anti-renin monoclonal antibodies 2D12/F37 and 4G1/ F55 (Galen et al, 1984) were a gift from Sanofi-Pasteur, France. The antibody 2D12/F37 was used at a final concentration of 2 mg/ml.…”