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 Dwyer, J. M. Articles by Mackay, I. R. Search for Related Content PubMed Articles by Dwyer, J. M. Articles by Mackay, I. R.

Specificity and Nature of the Antigen-Combining Sites on Fetal and Mature Thymus Lymphocytes^1,2,

From the Clinical Research Unit of The Walter and Eliza Hall Institute of Medical Research and The Royal Melbourne Hospital, Victoria 3050, Australia

Abstract

The thymus of several species was examined for antigen-binding lymphocytes (ABL), by using autoradiography and ¹²⁵I-labeled antigens, flagellin from Salmonella adelaide and hemocyanin from Jasus lalandii. Counts of ABL in thymic cell suspensions, expressed per 10⁴ lymphocytes, varied according to the species and antigen used. For flagellin the count of thymic ABL was considerably greater in the human fetus (182 ± 50) than the mouse fetus (2.9 ± 0.5), but for hemocyanin was greater in the mouse (36 ± 8.5) than the human (10 ± 2.5). In man and mouse counts of thymic ABL fell steadily with increasing age, from fetal to late adult life. The property of antigen binding could not be attributed to cytophilic antibody because this was not passively conferred on to lymphocytes in vitro or in vivo by antibody to flagellin in high titer. The in vivo experiment was on rats immunized with flagellin before pregnancy; antibody crossed the placenta yet failed to confer antigen-binding properties on lymphocytes of various fetal tissues. The binding of flagellin and hemocyanin to thymic lymphocytes in man and mouse was blocked by monospecific antisera to light chains and µ chains, even in high dilution. Most of the ABL in thymus cell suspensions would be expected to be thymus-derived (T) lymphocytes rather than immigrant B lymphocytes and the data were therefore interpreted as showing that such lymphocytes carry antigen-binding receptors of IgM character.

Footnotes

¹ Publication 1587 from The Walter and Eliza Hall Institute of Medical Research.

² This work was supported by grants from the National Health and Medical Research Council of Australia, and United States Public Health Service Grant AM 11234-04.