Functional Cutaneous Lymphocyte Antigen Can Be Induced in Essentially All Peripheral Blood T Lymphocytes

Abstract

The cutaneous lymphocyte–associated antigen (CLA) is a skin–homing receptor expressed on a minority of memory–type peripheral blood T (PBT) lymphocytes. Induction of high–level CLA expression in PBT has previously been difficult to accomplish in vitro. Here we report that constitutive CLA expression could be readily induced in virtually all PBT by various polyclonal activators. There was no requirement for accessory cells or addition of other mediators except for IL–2 for maintaining cell survival. Absence of serum in the culture medium was important for optimal induction of CLA. The number of T cells adhering to E–selectin as well as tethering and shear stress resistance under hydrodynamic flow increased in correlation with the level of cell surface CLA expressed. Clonal analysis of CLA induction revealed that in serum–containing medium, which permits the majority of T cells to expand, only a minority of clones did not express CLA. Such T cells could be induced to highly express CLA within 8 days by switching from serum–containing to serum–free medium. This cell–surface phenotype change was closely associated with acquisition of E–selectin ligand activity. Fucosyltransferase VII, which is believed to be important for the generation of the CLA epitope on the P–selectin glycoprotein ligand–1 (PSGL–1) backbone, was shown to be significantly increased in CLA–positive versus CLA–negative T cell populations by PCR analysis. Our findings are consistent with the idea that restriction of CLA expression after activation, rather than positive selection of predetermined T cell subpopulations exposed to restrictive stimulatory conditions in unique microenvironments, may be important in vivo.

In Vitro Differentiation from Naive to Mature E-Selectin Binding CD4 T Cells: Acquisition of Skin-Homing Properties Occurs Independently of Cutaneous Lymphocyte Antigen Expression

“…It remains unknown, however, where, when, and how the commitment of T cells to the skin-homing phenotype is determined; we cannot be sure whether the induction of CLA expression on these T cells occurred in temporal correlation with the acquisition of skin-homing properties or whether the induction of CLA appeared afterward. In this regard, recent kinetic studies have demonstrated that optimal CLA induction on T cells is a relatively slow process even in serum-free medium highly permissive for CLA expression (18,19), and we have also seen a similar requirement for 5 days or more to generate CLA-positive T cells from naive T cells in vitro (20,21). Nevertheless, the acquisition of skin-homing properties has been thought to occur rapidly upon activation.…”

Degree of CD25 Expression in T-Cell Lymphoma Is Dependent on Tissue Site

“…CLA can also be expressed in MF/SS in PB, but analysis of sorted cell populations has demonstrated that circulating tumor cells are present in both the CLAϩ and CLA-negative T-cell populations (29). This suggests that CTCL may shed or rapidly modulate CLA once outside of the skin microenvironment as has been demonstrated for nonneoplastic T cells (30,31).…”

Identification of cutaneous lymphocyte-associated antigen as sialyl 6-sulfo Lewis X, a selectin ligand expressed on a subset of skin-homing helper memory T cells

“…It should be noted in future clinical applications of HECA-452 for defining CLA, however, that this antibody cross-reacts with conventional, nonsulfated sialyl Le x , which is induced on activated lymphocytes, making it appear that CLA is carried by virtually all activated lymphocytes in certain in vitro settings. 50 Moreover, the antibody essentially reacts to all granulocytes and behaves merely as an anti-sialyl Le x antibody. We propose that the major and essential part of CLA on skin-homing helper memory T cells in normal peripheral blood is sialyl 6-sulfo Le x , which can be defined as HECA-452 ϩ CSLEX-1 Ϫ or simply as G152 ϩ .…”