T-LYMPHOCYTES FROM SEZARY-SYNDROME PATIENTS EXPRESS BETA(1) INTEGRINSWHOSE BETA(1-6)-BRANCHED N-LINKED OLIGOSACCHARIDES REFLECT THEIR ADHESIVE CAPACITY

Sezary syndrome (Sz), characterized by slowly progressing clonal proli feration of CD4(+), CD45 RO+ T cells, has several forms that are disti nguished according to the epidermotropic properties of the pathologica l 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 patie nts [Sz beta(1-6)(+)] expressed high levels of beta(1-6)-GlcNAc-branch ed N-linked oligosaccharides while T lymphocytes from other patients [ Sz beta(1-6)(-)] did not. Because this observation suggests the possib ility of two forms of St, distinguished according to the expression ra te of these glycans, we looked for a possible relationship between thi s expression rate and T-cell adhesiveness. Using an original protocol (Braut-Boucher F, Pichon J, Rat P, Adolphe M, Aubery M, Font J. J Immu nol Methods 1995;178:41), we observed that T lymphocytes obtained from the Sz beta(1-6)(+) patients adhered less to normal keratinocyte mono layers than T lymphocytes from Sz beta(1-6)(-) patients and normal don ors. As assessed by FAGS analysis, all the integrin-subunits studied w ere more expressed on Sz beta(1-6)(-) especially alpha(4), alpha(5), b eta(1) and beta(2), than on Sz beta(1-6)(+) and normal lymphocytes. Al though these results suggest that beta(1)- and beta(2)-integnn express ion is involved in the adhesive properties of these T-cells, other fac tors, such as glycosylation, may also contribute. To demonstrate this possibility, we sought the presence of beta(1-6)-GlcNAc-branched N-lin ked oligosaccharides on beta(1) integrins expressed by T lymphocytes f rom Sz patients. Immunoblot experiments, performed using the specific lectin from Phaseolus vulgaris (Leukoagglutinin form), showed that onl y 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.