Junctional adhesion molecule C (JAM-C) distinguishes CD27+ germinal center B lymphocytes from non-germinal center cells and constitutes a new diagnostic tool for B-cell malignancies.

in Leukemia by C Ody, S Jungblut-Ruault, D Cossali, M Barnet, M Aurrand-Lions, B A Imhof, T Matthes

TLDR

  • Research proposes junctional adhesion molecule C (JAM-C) as a new identification tool for B-cell lymphoma diagnosis, distinguishing between JAM-C- and JAM-C+ lymphoproliferative syndromes based on its expression patterns.

Abstract

Differentiation of naïve B cells into plasma cells or memory cells occurs in the germinal centers (GCs) of lymph follicles or alternatively via a GC- and T-cell-independent pathway. It is currently assumed that B-cell lymphomas correlate to normal B-cell differentiation stages, but the precise correlation of several B-cell lymphomas to these two pathways remains controversial. In the present report, we describe the junctional adhesion molecule C (JAM-C), currently identified at the cell-cell border of endothelial cells, as a new B-cell marker with a tightly regulated expression during B-cell differentiation. Expression of JAM-C in tonsils allows distinction between two CD27+ B-cell subpopulations: JAM-C- GC B cells and JAM-C+ non-germinal B cells. The expression of JAM-C in different B-cell lymphomas reveals a disease-specific pattern and allows a clear distinction between JAM-C- lymphoproliferative syndromes (chronic lymphocytic leukemia, mantle cell lymphoma and follicular lymphoma) and JAM-C+ ones (hairy cell leukemia, marginal zone B-cell lymphoma). Therefore, we propose JAM-C as a new identification tool in B-cell lymphoma diagnosis.

Overview

  • The study explores the correlation between B-cell lymphomas and normal B-cell differentiation stages, specifically examining the expression of the junctional adhesion molecule C (JAM-C) in B cells.
  • The researchers investigate the expression of JAM-C in tonsils and identify two CD27+ B-cell subpopulations: JAM-C- GC B cells and JAM-C+ non-germinal B cells.
  • The primary objective is to propose JAM-C as a new identification tool for B-cell lymphoma diagnosis by examining its expression in different lymphomas and distinguishing between JAM-C- and JAM-C+ lymphoproliferative syndromes.

Comparative Analysis & Findings

  • The study found that JAM-C expression allowed clear distinction between JAM-C- lymphomas (chronic lymphocytic leukemia, mantle cell lymphoma, and follicular lymphoma) and JAM-C+ lymphomas (hairy cell leukemia, marginal zone B-cell lymphoma).
  • The expression of JAM-C in tonsils identified two CD27+ B-cell subpopulations, JAM-C- GC B cells and JAM-C+ non-germinal B cells, which were previously indistinguishable.
  • The results suggest that JAM-C expression is tightly regulated during B-cell differentiation and can be used as a marker to distinguish between normal and neoplastic B cells.

Implications and Future Directions

  • The study's findings propose JAM-C as a new identification tool for B-cell lymphoma diagnosis, allowing for more accurate and specific classification of lymphomas.
  • Future research could focus on investigating the functional role of JAM-C in B-cell differentiation and its potential as a therapeutic target for B-cell lymphomas.
  • The study highlights the need to further investigate the correlation between B-cell lymphomas and normal B-cell differentiation stages, potentially uncovering new insights into disease mechanisms and diagnosis.
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