HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Chisari, F. V. Articles by Edgington, T. S. Search for Related Content PubMed Articles by Chisari, F. V. Articles by Edgington, T. S.

Recovery of Soluble Sheep Erythrocyte Receptor from the T Lymphocyte Surface by Proteolytic Cleavage¹

From the Department of Molecular Immunology, Scripps Clinic and Research Foundation, La Jolla, California 92037

Abstract

Proteolytic digestion of the human T lymphoblastoid cell line (Molt-4) and of peripheral blood lymphocytes by trypsin, chymotrypsin, and pronase results in a progressive, time- and dose-dependent diminution of T lymphocyte — sheep red blood cell (SRBC) rosette formation, whereas thrombin, plasmin, collagenase, DNAse, and phospholipase have no effect. Complete abrogation of SRBC binding is achieved when lymphocytes (1 x 10⁸/ml) are incubated with either trypsin or chymotrypsin at 10 µg/ml for 30 min, and ;50% abrogation is observed between 3 to 10 min. Preincubation of SRBC with the 10 min and 20 min lymphocyte digest supernatants inhibited their subsequent binding by normal T lymphocytes by as much as 64%. Thirty-minute digests were less inhibitory. Equivalent digests from several human B lumphoblastoid cell lines and from a non-rosetting clone of Molt-4 cells were not inhibitory. Polyacrylamide gel electrophoresis followed by elution of serial gel slices revealed four distinct inhibitory bands (I–IV) in the 20-min digest supernatant whereas only bands I–III and band IV were present in the 10-min and 30-min digest supernatants, respectively, suggesting progressive proteolysis of a distinct receptor. These experiments indicate that the binding of SRBC by human T lymphocytes represents a receptor-ligand interaction rather than a nonspecific electrical charge phenomenon and that the receptor is a discrete molecular species which can be isolated from the surface of T but not B lymphocytes by limited enzymatic proteolysis.

Footnotes

¹ This work was supported by National Institutes of Health Grants AI-13393 and CA-14346. This is Publication No. 1221 from Scripps Clinic and Research Foundation, La Jolla, California.

² F. V. C. is the recipient of RCDA AI-00174 from the National Institutes of Health, Bethesda, Maryland.