The epidermotropic mycosis fungoides associated alpha1beta1 integrin (VLA-1, CD49a/CD29) is primarily a collagen IV receptor on malignant T cells.

Abstract

Several of the beta1 integrin receptors [very late antigen (VLA) molecules] for extracellular matrix (ECM) proteins are expressed by malignant T cells in cutaneous T-cell lymphoma (CTCL). We evaluated the function of VLA-1, a beta1 integrin specifically expressed in epidermotropic mycosis fungoides (MF), in CD4+ leukemic T cells Jurkat line). We found that Jurkat cells adhere significantly to collagens only after their activation with phorbol 12-myristate 13-acetate (PMA). However, the adhesion to collagen IV (but not to collagen I) of Jurkat cells selected for expressing increased levels of VLA-1 (with unchanged levels of VLA-2, the second collagen integrin receptor) was significantly enhanced relative to that of "VLA-1 low" cells. Monoclonal antibody (mAb) 1B3.1, directed against the collagen binding domain of VLA-1, inhibited adhesion to collagen IV and to collagen I by 36.67%+/-5.25% and 18%+/-4.32%, respectively (p<0.05), whereas the inhibition by anti-VLA-2 mAb PIE6 was comparable on both collagens (25%+/-7.48% and 36.3%+/-0.94%, respectively; p<0.09). Immuno-histochemical studies of skin biopsies from 10 untreated MF patients showed that in all cases at least 10% of the lymphocytes residing in the epidermis are VLA-1+VLA-2-. While not directly applicable to MF, the demonstrated functions of VLA-1 in leukemic Jurkat cells, together with its expression in MF skin, suggest a role for VLA-1 integrins in epidermotropism in a small proportion of leukemic MF cells.

• Authors: I Bank, E Rapman, R Shapiro, G Schiby, I Goldberg, A Barzilai, H Trau, H Gur
• Journal: Journal of cutaneous pathology (J Cutan Pathol) Vol. 26 Issue 2 Pg. 65-71 (Feb 1999) ISSN: 0303-6987 [Print] United States
• PMID: 10082395 (Publication Type: Journal Article)

Chemical References

• Antigens, CD
• Integrin alpha1beta1
• Integrins
• Receptors, Cell Surface
• extracellular matrix receptor
• Collagen

Topics

• Antigens, CD (metabolism)
• CD4-Positive T-Lymphocytes (metabolism)
• Cell Adhesion
• Collagen (metabolism)
• Humans
• Immunohistochemistry
• Integrin alpha1beta1
• Integrins (biosynthesis, metabolism)
• Jurkat Cells
• Mycosis Fungoides (immunology, metabolism)
• Receptors, Cell Surface (metabolism)
• Skin Neoplasms (immunology, metabolism)