Related Experiment Video

Updated: Aug 13, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry
14:29

Examination of Thymic Positive and Negative Selection by Flow Cytometry

Published on: October 8, 2012

Selective expression of CD45 isoforms and of maturation antigens during human thymocyte differentiation: observations

L M Pilarski1, J P Deans

  • 1Department of Immunology, University of Alberta, Edmonton, Canada.

Immunology Letters
|June 1, 1989
PubMed

Selective expression of high and low molecular weight isoforms of CD45 (T200) occurs coincident with activation of mature T lymphocytes. Expression of CD45 p180 and CDw29 defines antigen-experienced memory T cells in the periphery, and expression of CD45R (CD45 p205/220) defines naive T cells. Upon activation, CD45R+ T cells lose CD45R and acquire CD45 p180 and high density CDw29. In this review we discuss the expression of CD45 isoforms, CDw29, pgp-1 and CD1 on human thymocytes and develop the hypothesis that expression of CD45R marks the generative thymic lineage while expression of CD45 p180 marks those cells destined for intrathymic death. This hypothesis is supported by evidence from phenotypic, molecular and functional analysis of thymocyte subsets. We propose that expression of high molecular weight isoforms of CD45 is essential for growth and differentiation of immature T cells and that inappropriate rearrangement or specificity of TCR activates a transition from expression of CD45R to that of CD45 p180 and intrathymic death.

More Related Videos

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells07:20

Isolation, Identification, and Purification of Murine Thymic Epithelial Cells

Published on: August 8, 2014

Preparation of Single-Cell Suspension of Mouse Thymic Epithelial Cells and Staining of Intracellular Molecules for Flow Cytometric Analysis09:41

Preparation of Single-Cell Suspension of Mouse Thymic Epithelial Cells and Staining of Intracellular Molecules for Flow Cytometric Analysis

Published on: July 26, 2024

Related Concept Videos

T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...