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 Galili, U. Articles by Schlesinger, M. Search for Related Content PubMed Articles by Galili, U. Articles by Schlesinger, M.

Subpopulations of Human Thymus Cells Differing in Their Capacity to form Stable E-Rosettes and in Their Immunologic Reactivity¹

From the Department of Experimental Medicine and Cancer Research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel

Abstract

The majority of human thymus cells from young donors form stable E-rosettes with sheep red blood cells (SRBC) that do not disintegrate after prolonged incubation at 37°C. With advancing age the proportion of thymus cells forming such rosettes decreases gradually. The thymus of a patient receiving prednisone treatment was found to contain only a few cells that formed stable E-rosettes.

The minor population of thymus cells that fails to form stable E-rosettes (non-rosetting or NR cells) was isolated and tested for its cell surface markers and immunologic reactivity in vitro. Most of the NR-cells were capable of forming regular E-rosettes with SRBC at room temperature. Like the majority of human thymus cells they were sensitive to the cytotoxic effect of normal rabbit serum. Lymphocytes with B cell markers constituted less than 0.2% of the original thymus cell suspensions, but about 1 to 3% of the NR-population.

Thymus cells from donors over the age of 36 and from a prednisone-treated child responded in vitro to stimulation with either phytohemagglutinin (PHA) or concanavalin A (Con A). Unfractionated thymus cells from children up to the age of 14 failed to react to either PHA or Con A, but their NR-population responded vigorously to both lectins. In contrast to unfractionated thymus cell suspensions from children, the NR fraction showed a significant reactivity in mixed lymphocyte cultures with mitomycin-C treated allogeneic lymphocytes.

It is concluded that like the thymus of other species, the human thymus contains a minor population of cortisone-resistant cells endowed with many of the immunologic properties characteristic for peripheral T lymphocytes.

Footnotes

¹ This study was supported by a grant from the Goldhirsch Foundation and by a Lady Davis Endowment.