T lymphocytes from Sezary syndrome patients express β1 integrins whose β(1-6)-branched N-linked oligosaccharides reflect their adhesive capacity

Sezary syndrome (Sz), characterized by slowly progressing clonal proliferation of CD4(+), CD45 RO+ T cells, has several forms that are distinguished according to the epidermotropic properties of the pathological cells. In a recent paper (Derappe C, Haentjens G, Lemaire S, Feugeas JP, Lebbe C, Pasqualetto V, Bussel A, Aubery M, Neel D. Leukemia 1996;10:138), we observed that T lymphocytes from most of the Sezary patients [Sz beta(1-6)(+)] expressed high levels of beta(1-6)-GlcNAc-branched N-linked oligosaccharides while T lymphocytes from other patients [Sz beta(1-6)(-)] did not. Because this observation suggests the possibility of two forms of St, distinguished according to the expression rate of these glycans, we looked for a possible relationship between this expression rate and T-cell adhesiveness. Using an original protocol (Braut-Boucher F, Pichon J, Rat P, Adolphe M, Aubery M, Font J. J Immunol Methods 1995;178:41), we observed that T lymphocytes obtained from the Sz beta(1-6)(+) patients adhered less to normal keratinocyte monolayers than T lymphocytes from Sz beta(1-6)(-) patients and normal donors. As assessed by FAGS analysis, all the integrin-subunits studied were more expressed on Sz beta(1-6)(-) especially alpha(4), alpha(5), beta(1) and beta(2), than on Sz beta(1-6)(+) and normal lymphocytes. Although these results suggest that beta(1)- and beta(2)-integnn expression is involved in the adhesive properties of these T-cells, other factors, such as glycosylation, may also contribute. To demonstrate this possibility, we sought the presence of beta(1-6)-GlcNAc-branched N-linked oligosaccharides on beta(1) integrins expressed by T lymphocytes from Sz patients. Immunoblot experiments, performed using the specific lectin from Phaseolus vulgaris (Leukoagglutinin form), showed that only the beta(1) integrin subunit expressed by T lymphocytes from Sz beta(1-6)(+) patients carried these glycans, supporting the concept of the involvement of T-cell glycosylation in the evolution of St. (C) 1998 Elsevier Science Ltd. All rights reserved.