Expression of OX40 and OX40 ligand (gp34) in the normal and myasthenic thymus.

Abstract

OBJECTIVES:

To examine the expression of OX40, an activated memory T-cell marker, and its ligand (OX40L), a set of molecules for T-cell-B-cell interaction, and other lymphocyte activation markers in the thymuses of myasthenia gravis (MG) and controls.

MATERIAL AND METHODS:

We studied the expression of OX40, OX40L, IL-2Ralpha and HLA-DR in the thymic tissues of MG and controls using immunocytochemistry and flowcytometry.

RESULTS:

In both hyperplastic thymus of MG and control thymus, OX40+ cells were scattered mainly in the medulla with much fewer OX40L+ cells being distributed in the corticomedullary junctions. IL-2Ralpha and HLA-DR were expressed in the medulla at higher frequencies as compared with OX40 in controls as well as MG. In contrast, the numbers of OX40+ cells around the germinal centers (GC) were significantly greater than those of control thymuses, and some mononuclear cells in GC were OX40L+. A considerable number of OX40+ cells were seen in the thymic tissues adjacent to thymomas. OX40+ cells were CD4+ CD8- or CD4+ CD8+ and were mostly HLA-DR-. (The coexpression of OX40 and IL-2Ralpha on activated CD4+ T cells was previously reported.)

CONCLUSION:

OX40, expressed in a fraction of activated CD4+ T cells, may be upregulated in thymic tissues adjacent to GC and thymoma in MG, and OX40 may interact with OX40L in GC to enhance anti-acetylcholine receptor antibody production in MG.

• Authors: J Onodera, T Nagata, K Fujihara, M Ohuchi, N Ishii, K Sugamura, Y Itoyama
• Journal: Acta neurologica Scandinavica (Acta Neurol Scand) Vol. 102 Issue 4 Pg. 236-43 (Oct 2000) ISSN: 0001-6314 [Print] Denmark
• PMID: 11071109 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• Antigens, CD
• HLA-DR Antigens
• Ligands
• Receptors, Tumor Necrosis Factor

Topics

• Adolescent
• Adult
• Antibodies, Monoclonal (metabolism)
• Antigens, CD (metabolism)
• Cerebral Cortex (metabolism)
• Female
• Flow Cytometry
• HLA-DR Antigens (metabolism)
• Humans
• Ligands
• Male
• Medulla Oblongata (metabolism)
• Middle Aged
• Myasthenia Gravis (genetics, metabolism)
• Receptors, Tumor Necrosis Factor (genetics, metabolism)
• Thymus Gland (metabolism, pathology)