Adhesion receptor profile of thymic B-cell lymphoma.

Primary thymic B-cell lymphoma is clinically characterized by aleukemic, highly aggressive local growth, infrequent distant metastasis, and infrequent secondary lymph node involvement. VLA-1 to VLA-6 are cell surface molecules binding to matrix molecules such as collagen, fibronectin, epiligrin, and laminin. VLA-4 additionally binds to VCAM-1 and ICAM-2, thus mediating intercellular adhesion. Other molecules involved in cell/cell adhesion are LFA-1 (CD11a/CD18), Mac-1(CD11b/CD18) and their ligand ICAM-1 (CD54), p150,95 (CD11c/CD18), LFA-3 (CD58), CD44, and LECAM-1. Twenty-three tumors, together with normal lymphoid tissue, were immunohistochemically examined to investigate the expression pattern of these molecules in thymic B-cell lymphomas and in their putative normal counterparts, namely thymic medullary B cells. Thymic B-cell lymphomas consistently lacked VLA-1,-2,-3,-5,-6, and CD11b, expressed ICAM-1 in 21 of 23 cases but were heterogenous for VLA-4, LFA-1, CD11c, LFA-3, CD44, and LECAM-1. Presence of LFA-1 correlated with LFA-3 expression (P = 0.029). The receptor profile of thymic B-cell lymphoma was reminiscent of the expressional status of normal thymic medullary B cells in some aspects but deviated in others: Assuming that, in terms of differentiation, thymic B-cell lymphoma is related to the asteroid variant of thymic medullary B cells, a propensity to down-regulate/lose VLA-4, CD11a, CD44, and LECAM-1 would have to be supposed in conjunction with a tendency to overexpress ICAM-1 and LFA-3. Sclerosis as an inconsistent phenomenon in thymic B-cell lymphoma was absent in 8 of 23 tumors. Presence of sclerosis correlated with LECAM-1 expression of the tumor cells (P = 0.038). Recent studies suggest that a locally growing/aleukemic phenotype of a B-cell neoplasia might be determined by the phenotype VLAs-, LFA-1+, ICAM-1+, CD44-, and LECAM-1-. Our data corroborate this view.     

Immunopathology of cutaneous T-cell lymphomas.

In this study the authors attempted to establish immunopathologic criteria for the distinction of various T-cell lymphomas affecting the skin. We studied skin specimens from 27 patients with mycosis fungoides (MF) (n = 12), the Sézary syndrome (SS) (n = 6), adult T-cell leukemia (ATL) (n = 4), and nonepidermotropic T-cell lymphoma of large cell (n = 4) and lymphoblastic (n = 1) types. Identification of tumor cells in mixed cell populations and detection of weak expression of surface antigens by tumor cells was facilitated by immunoelectron microscopy. The mature helper T-cell phenotype (T11+ T3+ T4+) was found in 14 of 18 cases of MF/SS. One case of MF had a cytotoxic/suppressor (T4- T8+ 3A1+) phenotype; one with frequent blastic cells showed only weak expression of T4 antigen; 2 cases of SS were T11-. Tumor cells infiltrating the skin expressed 3Al antigen in 44% and cellular activation antigens Ia and/or Tac in 78% of patients with MF/SS. No consistent phenotypic differences were found between ATL cells from ATLV (HTLV) antibody-positive patients and tumor cells of patients with MF/SS who lacked this antibody. In contrast, a group of nonepidermotropic T-cell lymphomas showed phenotypic differences from MF/SS and ATL in all but 1 case. These cases were distinguished by the frequent absence of T3, T4, and Leu 1 antigens in 3 large-cell lymphomas; frequent expression of Ki-1 antigen, a Hodgkin's disease-associated antigen, in 2 cases with RS-like cells; and an immature thymocyte phenotype in lymphoblastic lymphoma. These findings demonstrate that tumor-cell phenotypes can be useful in distinguishing different histologic types of cutaneous T-cell lymphoma.     

Chemokines stimulate human T lymphocyte transendothelial migration to utilize VLA-4 in addition to LFA-1

Lymphocyte infiltration in inflammation is induced by the dual actions of chemokines and cell adhesion molecules. The role of LFA-1 and VLA-4 in chemokine-induced T cell transendothelial migration (TEM) across cytokine-activated endothelium has not been examined. LFA-1, but not VLA-4, mediated blood T cell TEM to RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha), and stromal cell-derived factor-1 (SDF-1), and across tumor necrosis factor alpha (TNF-alpha) or interferon-gamma (IFN-gamma) -stimulated endothelial cells (EC). Chemokine stimulation in combination with TNF-alpha activation of EC induced TEM, which was partially mediated by VLA-4. SDF-1 increased a beta1-integrin activation epitope on T cells and enhanced VLA-4-mediated adhesion. Thus, LFA-1 mediates TEM under most conditions, but VLA-4 can also mediate TEM, although, in contrast to LFA-1, this requires exogenous chemokines and EC activation. In addition, an LFA-1- and VLA-4-independent pathway of lymphocyte TEM can also be induced by SDF-1.     

Expression of monoclonal antibody HML-1-defined alpha E beta 7 integrin in cutaneous T cell lymphoma.

Considering that integrins may play a major role in the localization in distinct biological features as well as in the dissemination of several types of lymphomas, we studied the expression of the monoclonal antibody HML-1-defined alpha E beta 7 integrin (CD103) in the clinically and histologically determined stages of 53 mycosis fungoides (MF) skin biopsies and in 16 affected lymph nodes. Immunoperoxidase staining revealed HML-1 immunoreactivity with T cells in the early stages of disease (patch and plaque stage MF). HML-1 expression was more pronounced on infiltrating epidermal than on dermal T cells. In contrast to early stages, tumor stage MF and lymph nodes affected in the course of cutaneous T cell lymphoma were HML-1 negative. We found a strong association between HML-1 expression, epidermotropism of infiltrating T cells, and the stage of disease. We provide evidence that: 1) the loss of the HML-1 antigen on T cells in MF is a marker of poor prognosis and 2) because the HML-1 antigen is selectively expressed on T lymphocytes of epithelial sites such as gut and skin, our results are compatible with the view that alpha E beta 7 integrins perform homing receptor functions for epitheliotropic T cells.     

Expression of cell adhesion molecules and their beta1 and beta2 integrin ligands in human liver peliosis

The expression of the following cell adhesion molecules and their beta1 and beta2 integrin ligands was investigated in the liver tissue from 3 patients with non-bacillar peliosis using light and electron microscope immunohistochemistry: intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, platelet endothelial cell adhesion molecule-1 (PECAM-1), leukocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1), and very late antigen-4 (VLA-4). We found a parallel enhancement of the adhesion molecules expression in the dilated sinusoids and cavities in all 3 cases with peliosis. Mononuclear blood cells were detected in the sinusoids and sometimes perisinusoidally. These cells were mainly ICAM-1-, LFA-1-, and VLA-4-positive. At the ultrastructural level, ICAM-1-positive immune deposits were observed on the membrane of sinusoidal endothelial cells, Kupffer cells, and hepatocytes. The expression of cell adhesion molecules on liver sinusoids in peliosis is probably triggered by factors released from damaged endothelial cells and hepatocytes. The prevalence of the ICAM-1/LFA-1 and VCAM-1/VLA-4 patterns of mononuclear blood cell/sinusoidal cell interactions could support the macrophage-induced or lymphocyte-induced type of liver injury. PECAM-1 was also included in the non-specific immune response in peliosis. The presence of erythrostasis or thrombosis in liver sinusoids could participate in the induction of adhesion molecule expression in peliosis.     

Lack of adhesion molecules in testicular diffuse centroblastic and immunoblastic B cell lymphomas as a contributory factor in malignant behaviour

Diffuse large B-cell lymphoma of the testis is a rare tumour, often with disseminated disease. According to the Kiel Classification, these lymphomas are of centroblastic or immunoblastic type, corresponding in the Working Formulation to malignant lymphoma, large cell non-cleaved and large cell immunoblastic, respectively. Adhesive cell-cell and cell-matrix interactions are generally assumed to play an important part in the metastatic process, and to find clues to the highly malignant biological behaviour of this tumour we examined expression of integrins and other adhesion molecules on the tumour cells and the presence of matrix proteins. Few adhesion molecules appeared to be expressed. CD44 was expressed in 10/12 lymphomas, CD49f/VLA-6 was positive in 5/12 cases, and CD49d/VLA-4, CD54 and CD62L were detectable in a small number (2–3) of lymphomas. All other adhesion molecules were lacking. This expression pattern is suggestive of a high metastatic potential: the tumour cells seem to be poorly attached to the extracellular matrix, to each other and to other cells (CD54-, CD11a-, CD58-). The adhesion molecules expressed, CD44, CD49f/VLA-6 and CD49d/VLA-4, have been reported to play a part in dissemination, mediating intravasation (CD49f/VLA-6) and extravasation (CD44, CD49d/VLA-4). This profile of adhesion molecules may explain, at least in part, the specific biological behaviour of these lymphomas with early and rapid dissemination.     

Immunophenotyping and gene rearrangement analysis provide additional criteria to differentiate between cutaneous T-cell lymphomas and pseudo-T-cell lymphomas.

Differentiation between cutaneous pseudo-T-cell lymphomas and cutaneous T-cell lymphomas (CTCLs) may be extremely difficult. In this study, it was investigated whether demonstration of an aberrant phenotype and detection of clonal T-cell receptor gamma (TCR gamma) gene rearrangements can be used as additional differential diagnostic criteria. Immunohistochemical studies and TCR gamma gene rearrangement analysis using a polymerase chain reaction with primers specific for V gamma 1-8 and V gamma 9 gene segments in combination with denaturing gradient gel electrophoresis (PCR/ DGGE) were performed on frozen material of 11 pseudo-T-cell lymphomas and 17 CTCLs, including 9 cases of mycosis fungoides (MF) and 8 pleomorphic CTCLs. Clonal TCR gamma gene rearrangements were found in 66% of patch/plaque-stage MF and 100% of tumor-stage MF and pleomorphic CTCL, but not in any of 10 pseudo-T-cell lymphomas studied. Aberrant expression of CD2, CD3, and/or CD5 antigens was noted in 3 of 6 (50%) cases of patch/plaque-stage MF, all three cases of tumor-stage MF, and 5 of 8 (62%) pleomorphic CTCLs, but not in any of the 11 pseudo-T-cell lymphomas. Moreover, in pseudo-T-cell lymphomas exhibiting a nodular or diffuse growth pattern, a considerable admixture with reactive CD8+ T cells (15 to 60%), B cells (up to 20%), and macrophages was a characteristic finding. In conclusion, the results of this study suggest that demonstration of clonal TCR gene rearrangements and an aberrant phenotype, as well as demonstration of many admixed CD8+ T cells and B cells can be considered as useful additional criteria in the differentiation between pseudo-T-cell lymphomas and CTCLs.     

Dual inhibition of VLA-4 and LFA-1 maximally inhibits cutaneous delayed-type hypersensitivity-induced inflammation.

Lymphocytes express surface receptors that mediate adhesion to endothelial cells and control T cell migration into inflammatory sites. Lymphocyte VLA-4 and LFA-1 mediate adhesion to cytokine-activated endothelium, but the contribution of these molecules to in vivo migration and lymphocyte mediated inflammation is not clear. Here we show that both VLA-4 and LFA-1 contribute to not only lymphocyte adhesion but to in vivo lymphocyte migration in the rat and that nearly complete inhibition of lymphocyte accumulation is observed when both integrins are blocked. Furthermore, inhibition of delayed-type hypersensitivity-induced inflammation, as quantified by skin induration and fibrin deposition, is observed with either anti-VLA-4 or anti-LFA-1, but much stronger inhibition is observed with a blockade of both integrins. Thus, dual inhibition of the VLA-4 and LFA-1 pathways is required for a maximal anti-inflammatory effect in some types of T cell-mediated inflammation.     

Loss of expression of alpha4beta7 integrin and L-selectin is associated with high-grade progression of low-grade MALT lymphoma.

Expression of adhesion molecule in low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma of the gastrointestinal tract has been reported in recent years, but these reports have primarily focused on low-grade gastrointestinal MALT lymphoma. In this study, we examined the lymphocytic homing receptor alpha4beta7 integrin, L-selectin, and VLA-4 and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in low-grade lymphoma of the gastrointestinal tract and other organs such as the ocular adnexa and thyroid. We also observed changes in the expression pattern associated with high-grade transformation. Neoplastic cells in the gastrointestinal low-grade lymphoma and the low-grade component of high-grade MALT lymphoma were found to be alpha4beta7 integrin(+), L-selectin(+), whereas the gastrointestinal high-grade component and diffuse large B-cell lymphoma were found to be alpha4beta7 integrin(-), L-selectin(-). High endothelial venules in the gastric MALT lymphomas expressed MAdCAM-1. In the ocular adnexa low-grade MALT lymphoma, most cases were alpha4beta7 integrin(-), L-selectin(+); and in the thyroid, most cases of both low- and high-grade MALT lymphoma were alpha4beta7 integrin(-), L-selectin(-). These findings show that alpha4beta7 integrin and L-selectin may play an important role in the lymphocyte homing of gastrointestinal low-grade MALT lymphoma and in the loss of alpha4beta7 integrin expression throughout the course of high-grade progression.     

Expression of adhesion molecules in Langerhans' cell histiocytosis

Expression of adhesion molecules was investigated in six biopsy specimens of Langerhans' cell histiocytosis using immunocytochemistry. Cells with Langerhans' cell histiocytosis morphology were stained for ICAM-1, for the beta-1 integrins alpha-4 (VLA-4) and alpha-5 (VLA-5), and for the beta-2 integrins LFA-1, MAC-1 and p150,95. This pattern of reactivity was different from that of epidermal Langerhans' cells of the normal skin which were not immunostained. A variable number of CD68+ multinucleated giant cells was present in five biopsies. They were less reactive than the cells of Langerhans' cell histiocytosis for alpha-4 (VLA-4) and LFA-1, were positive for MAC-1 and p150,95 and were characterized by prominent expression of the beta-1 integrins alpha-2 (VLA-2), alpha-3 (VLA-3) and of VnR (alpha-v/ beta-3). The repertoire of adhesion molecules expressed by giant cells is indicative of profound cell-matrix interactions, whereas that of Langerhans' histiocytosis cells suggests particularly active cell–cell interactions. Blood vessels of the lesions were stained for beta-1 integrins, for vitronectin receptor and for molecules involved in adhesion and trans-endothelial migration of circulating leukocytes, such as ICAM-1, VCAM-1 and E-selectin. Additional findings were the observation of CD1a+ multinucleated giant cells in a single case, suggesting a possible lineage relationship with the histiocytosis cells, and the demonstration of some Ki-67+ Langerhans' cell histiocytosis cells and CD1a+ mitotic figures in four of six cases, indicating local proliferation of Langerhans' histiocytosis cells.     

Quantitative analysis of adhesion molecules on cellular constituents of the human uterine microenvironment under the influence of estrogen and progesterone

The uterus contains all the components of a tertiary lymphoid compartment. We hypothesize that specific leukocyte recruitment to the endometrium during the secretory phase of the menstrual cycle and early pregnancy limits the type of immunocyte that gains access. The present study utilized flow cytometry to define and quantify adhesion molecules possibly used by decidual infiltrating lymphocytes (DIL) as homing receptors, uterine microvascular myometrial endothelial cells (UtMVE-Myo) as addressins, and secretory endometrial stroma cells (STO) as retainment factors. Human umbilical cord vein endothelial cells and peripheral blood lymphocytes were used as control cells for comparison studies. DIL were composed of predominantly lymphocyte function-associated antigen (LFA)-1+, intercellular adhesion molecule (ICAM)-1+, LFA-2+, LFA-3+, gp150,95+, alpha1beta1+, Hermes cell adhesion molecule (H-CAM)+, and neural cell adhesion molecule (N-CAM)+ (CD56(bright)) memory/effector natural killer cells. A significant number of UtMVEC-Myo expressed platelet endothelial cell adhesion molecule (PECAM)-1, a percentage were uniquely LFA-3+, and alpha4 integrin expression was uniquely high. An increased number of STO uniquely expressed alpha3, beta3, and LFA-3, whereas alpha2, alpha4, alphaVbeta3, and H-CAM were significantly increased. Possible unique adhesions of DIL:UtMVEC-Myo included SLe(x):PECAM, vascular cell adhesion molecule-1:alpha4, and LFA-2:LFA-3, whereas DIL:STO included LFA-2:LFA-3 and N-CAM:N-CAM. Unique molecules on DIL may also associate with extracellular matrix (ECM) or complement on UtMVEC-Myo or STO to form gp150,95:fibrinogen/iC3b/C3dg, alpha1beta1:laminin (LM)/collagen (CO), and ICAM-1:fibronectin (FN) interactions. Bridges of ECM may also form between DIL and UtMVEC-Myo adhesion molecules including ICAM-1:FN:ICAM-1 and alpha4beta1:FN:alpha4beta1. DIL:ECM:STO interactions may involve alpha2beta1:CO:alpha2beta1, alpha3beta1:LM/CO/FN:alpha3beta1, alphaVbeta3:VN:alphaVbeta3, and H-CAM:hyaluronate:H-CAM. It is likely that many adhesion molecules play a role in the recruitment and retainment of specialized lymphocytes within the uterine microenvironment. (Mackay et al., 1990).     

The World Health Organization classification of malignant lymphoma: incidence and clinical prognosis in HTLV-1-endemic area of Fukuoka

New insights into the pathogenesis of lymphoid malignancies have been gained through novel genetic, molecular and immunological techniques. A new classification system for lymphoid malignancies, known as the new World Health Organization (WHO) classification, has been proposed recently based on these findings. The relative incidence of the subtypes of malignant lymphoma is known to differ according to geographic location. Adult T-cell leukemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukemia virus type 1 (HTLV-1), and the Kyushu islands are an HTLV-1 endemic area. To clarify the relationship between the histological classification and prognosis of lymphoid malignancies, we reclassified previous cases in our department and summarized our previous reports using the WHO classification. Of 933 cases of lymphoid malignancies, 471 (50%) were B-cell lymphoma, 396 (42%) T/natural killer (NK)-cell lymphoma and 41 (4%) Hodgkin lymphoma (HL). Analysis of clinical outcome showed favorable prognosis for HL, intermediate for B-cell lymphoma and poor prognosis for T-cell lymphoma. Among B-cell lymphomas, the commonest type was diffuse large B-cell lymphoma (n = 281; 60%). Marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) was diagnosed in 82 cases (17%), follicular lymphoma in 52 (11%) and mantle cell lymphoma in 24 (5%). Other less common lymphomas were Burkitt lymphoma (n = 9; 2%) and lymphoblastic lymphoma (n = 5; 1%). Using overall survival rates, the various B-cell lymphoma types could be divided into three broad groups for prognostic purposes: (i) low-risk group comprising follicular lymphoma and MALT; (ii) intermediate-risk group comprising diffuse large B-cell lymphoma and Burkitt lymphoma; and (iii) high-risk group comprising mantle cell lymphoma and lymphoblastic lymphoma. Among the T/NK-cell lymphomas, the commonest type was ATLL (n = 191; 48%), followed by peripheral T-cell lymphoma, unspecified (n = 83; 21%), angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) (n = 38; 10%), anaplastic large cell lymphoma (ALCL) (n = 22; 6%). Less common types were lymphoblastic lymphoma (n = 17; 4%), nasal and nasal-type NK/T-cell lymphoma (n = 17; 4%), mycosis fungoides (MF) (n = 9; 2%) and other rare types. With respect to clinical prognosis, T/NK-cell lymphomas fell into three groups: (i) relative low-risk group comprising ALCL, AILD, MF and lymphoblastic lymphoma; (ii) relative intermediate-risk group comprising NK/T-cell lymphoma and unspecified lymphoma; and (iii) extremely high-risk group comprising ATLL. Among the lymphoblastic lymphomas, B-cell type and T-cell type lymphomas exhibited different clinical outcomes. We conclude that the histological, phenotypic and genotypic classification of the new WHO system should be beneficial for the clinical approach to these tumors.     

Canine cutaneous epitheliotropic lymphoma (mycosis fungoides) is a proliferative disorder of CD8+ T cells.

Canine epitheliotropic lymphoma (mycosis fungoides [MF]) is a spontaneous neoplasm of skin and mucous membranes that occurs in old dogs (mean age 11 years) and has no breed predilection. The lesions evolve from a patch-plaque stage with prominent epitheliotropism into a tumor stage in which distant metastasis is observed. Unlike human MF, epitheliotropism of the lymphoid infiltrate is still prominent in tumor stage lesions. Tropism of the lymphoid infiltrate for adnexal structures, especially hair follicles and apocrine sweat glands, was marked in all clinical stages of canine MF. Twenty-three cases of MF were subjected to extensive immunophenotypic analysis in which reagents specific for canine leukocyte antigens and fresh frozen tissue sections of the canine lesions were used. Canine MF proved to be a T cell lymphoma in which the epitheliotropic lymphocytes consistently expressed CD3 (22 cases) and CD8 (19 cases); CD3+CD4-CD8- lymphocytes predominated in the remaining 4 cases. In this regard, canine MF clearly differed from human MF in which a CD4 immunophenotype predominates in the T cell infiltrate. Lack of expression of CD45RA by epitheliotropic T cells and intense expression of a beta 1 integrin (VLA-4-like) suggested that T cells in canine MF belonged to the memory subpopulation, as has been suggested for T cells in human MF. Pan-T cell antigen loss or discordant expression also proved useful as phenotypic indicators of neoplasia in canine MF. Loss of CD5 was observed in epitheliotropic T cells in 63% of cases. Discordance of neoplastic T cell Thy-1 expression was frequently observed between epithelial and dermal or submucosal compartments. We conclude that canine MF still represents a useful spontaneous animal disease model of human cutaneous T cell lymphoma, despite the immunophenotypic differences, which may reflect operational differences between human and canine skin-associated lymphoid tissue.     

The low molecular weight Dextran 40 inhibits the adhesion of T lymphocytes to endothelial cells

Dextrans are complex colloidal macromolecules widely used as haemorrheologic substances and anti-thrombotic agents. Here we describe a novel function of Dextran 40 by demonstrating an inhibition of T lymphocyte adhesion to endothelial cells (EC). We applied an established microassay in which constitutive and tumour necrosis factor-alpha (TNF-α)-induced binding of mouse T lymphoma cells (TK-1) to mouse endothelioma (eEND.2) cells is mediated by the interaction of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on EC with their counter-receptors the LFA-1 heterodimer (CD11a/CD18) and VLA-4 on T cells. Dextran 40 in therapeutically achievable levels (2–32 mg/ml) reduced both constitutive and TNF-α-stimulated TK-1 adhesion to eEND.2. Selective preincubation of eEND.2 or TK-1 revealed that Dextran 40 acted exclusively on the T cells. To explore further the mechanisms by which Dextran 40 interfered with TK-1 adhesion, their LFA-1 and VLA-4 expression was analysed by FACS. The surface expression levels of neither receptor were affected by Dextran 40. However, confocal microscopy revealed that Dextran 40 interfered with the activation-dependent capping and clustering of LFA-1 and VLA-4 on the surface of TK-1. We conclude that Dextran 40 inhibits the capacity of TK-1 T cells to adhere to eEND.2 endothelial cells and thus may be useful for therapeutic intervention in diseases associated with enhanced T lymphocyte binding to microvascular endothelium.     

Both LFA-1-positive and -deficient T cell clones require the CD2/LFA-3 interaction for specific cytolytic activation.

We investigated the capacity of T lymphocytes from a leukocyte adhesion-deficient (LAD) patient to respond to alloantigen. Leukocytes of this patient completely lacked LFA-1 surface expression due to the absence of mRNA coding for the LFA-1 beta chain. Despite the absence of LFA-1, T lymphocytes obtained from this patient, cultured with allogeneic stimulator cells (lymphoblastoid B cells JY), were capable of lysing JY cells. Furthermore, two T cell clones (one CD4+ and one CD8+), generated from this lymphocyte culture, specifically lysed the allogeneic lymphoblastoid JY cells. The cytolytic capacity of LFA-1-negative T lymphocytes and T cell clones was comparable to that of control LFA-1-positive T cells with allospecificity against JY. Detailed analysis of the CD4 positive and LFA-1-negative T cell clone demonstrated that it specifically recognized HLA-DQ. Antibody inhibition studies showed that the CTL/target cell interaction was mediated through the CD2/LFA-3 adhesion pathway. LFA-1 expressed by the target cells did not participate in the CTL/target cell conjugate formation and contributed only minimally to the cytotoxic activity. Moreover, when allogeneic LFA-1-deficient B cells, bearing the appropriate HLA-DQ alloantigen, were used as target cells, significant levels of specific cytotoxicity were measured, further excluding a role for LFA-1 in this interaction. The adhesion molecules, VLA-4, CD44 and L-selectin (LECAM1) were not involved. These results demonstrate that LFA-1-negative T lymphocytes can exert allospecific cytotoxicity and that CTL/target cell contact is mediated through the CD2/LFA-3 route. This observation may explain in part why in LAD patients viral infections, cleared largely by T cells, are less frequently observed than bacterial infections, in which phagocytic cells play a major role.     

Expression of adhesion molecules on infiltrating T cells in thyroid glands from patients with Graves' disease.

The present study was performed to elucidate the role of adhesion molecules in the pathogenesis of Graves' disease. Peripheral blood and intrathyroidal mononuclear cells were obtained from 14 patients with Graves' disease. The expression of adhesion molecules and HLA-DR antigen on CD4+ cells and CD4+ cell subpopulations was analysed by the two- or three-colour immunofluorescence method. The expression of adhesion molecules including LFA-1 alpha, LFA-1 beta, CD2, VLA-4 alpha and VLA-5 alpha on CD4+ cells in the thyroid gland was markedly higher than that in peripheral blood. In peripheral blood CD4+ cell subsets, the CD4+ CD45RO+ cell population had an enhanced expression of the adhesion molecules compared with the CD4+ CD45RA+ cell population. However, there was no significant difference in the expression of adhesion molecules by CD4+ cell populations and subsets between Graves' disease and healthy subjects. The thyroid gland from Graves' disease contained a higher percentage of CD4+ CD45RO+ cells and a lower percentage of CD4+ CD45RA+ cells. In intrathyroidal CD4+ cell subsets, the CD4+ CD45RO+ cell population had an increased expression of LFA-1 and CD2 compared with the CD4+ CD45RA+ cell population, but there was no significant difference in VLA-4 and VLA-5 expression between the two cell subsets. Furthermore, the expression of LFA-1 and CD2 on the CD4+ CD45RO+ cell population in the thyroid was significantly higher than that in matched peripheral blood. A similar finding was also observed for the CD4+ CD45RA+ cell population. The thyroid gland had an increased percentage of CD4+ HLA-DR+ cells compared with matched or healthy peripheral blood. However, there was no significant difference in the percentage of HLA-DR+ cells in the thyroid gland between CD4+ CD45RO+ cell and CD4+ CD45RA+ cell populations. These results suggest that increased expression of adhesion molecules on CD4+ cells may be responsible for the migration of these cells into thyroid glands and cellular interactions between these cells and thyroid epithelial cells.     

Role of LFA-1, ICAM-1, VLA-4 and VCAM-1 in lymphocyte migration across retinal pigment epithelial monolayers in vitro.

The blood-retinal barrier (BRB), which is composed of the retinal pigment epithelium (RPE) and retinal vascular endothelium, normally restricts the traffic of lymphocytes into the retina. During ocular inflammatory conditions such as posterior uveitis there is a large increase in lymphocyte migration across the BRB. The differential role played by the two barrier sites, however, remains unclear. To evaluate the role of the posterior BRB, the migration of CD4+ antigen-specific T-cell line through rat RPE cell monolayers was investigated in vitro using time-lapse videomicroscopy. The adhesion molecules involved in controlling transepithelial migration across normal and interferon-gamma (IFN-gamma)-activated RPE was assessed with monoclonal antibodies directed against cell adhesion molecules. Lymphocytes were treated with antibodies specific for CD11a (alpha L subunit of LFA-1), CD18 (beta 2 subnit of the leucam family) and CD49 d (alpha 4 subnit of very late activation antigen-4, VLA-4), and the RPE with antibodies specific for CD54 (intracellular adhesion molecule-1, ICAM-1) and CD 106 (vascular cell adhesion molecule-1, VCAM-1). Migration across unstimulated RPE was inhibited by antibodies to ICAM-1 (48.6 +/- 3.5% reduction), leucocyte functional antigen-1 (LFA-1) alpha (61 +/- 5.2%) and LFA-1 beta (63.2 +/- 4.7%), but not by antibodies to VLA-4. VCAM-1 was not expressed on untreated RPE. Following activation of the RPE monolayers for 72 hr with IFN-gamma, antibodies to LFA-1 alpha, LFA-1 beta and ICAM-1 inhibited migration by 49.9 +/- 9.4%, 63.6 +/- 5.5% and 47.7 +/- 4.2% respectively. Antibodies to VLA-4 and VCAM-1 blocked migration by 21.5 +/- 8.4% and 32.3 +/- 6.2%, respectively, which correlated with the induction of VCAM-1 expression on RPE and increased migration. Under these conditions blocking both VCAM-1 and ICAM-1 reduced migration by 70.9 +/- 2.3%, which was greater than the effect of blocking either of these molecules alone. These results demonstrate that the posterior barrier of the BRB utilizes the same principle receptor-ligand pairings in controlling lymphocyte traffic into the retina as the vascular endothelium of the anterior BRB.     

Primary cutaneous T-cell lymphoma: Clinicopathological features and prognostic parameters of 35 cases other than mycosis fungoides and cd30-positive large cell lymphoma

Within the group of primary cutaneous T-cell lymphomas (CTCLs), mycosis fungoides (MF), Sézary's syndrome (SS), and CD30-positive lymphomas have been delineated as clinicopathological entities. Primary CTCLs that do not belong to one of these entities represent a heterogeneous and ill-defined group of neoplasms. This paper describes the clinical and histological features of 35 of such cases. The object of t his study was to define prognostic parameters for this group of primary CTCLs. Using a slightly modified version of the updated Kiel classification, a subdivision was made into CTCL, pleomorphic, small cell type (n = 3); plemorphic, medium-sized cell type (n = 6); pleomorphic, large cell type (n = 18); and immunoblastic lymphomas (n = 8). Altogether, these lymphomas had a poor prognosis with estimated 2- and 4-year survival rates of 53 and 22 per cent, respectively. Patients with pleomorphic, small and medium-sized cell lymphomas (n = 9) proved to have a significantly better survival that those with pleomkorphic, large cell lymphomas (P = 0·032) and immunoblastic lymphomas (P = 0·008). Primary cutaneous immunoblastic lymphomas had the worst prognosis with an estimated 2-year survival rate of 14 per cent. Other parameters including age (P = 0·345), sex (P = 0·345), sex (P = 0·662), extent of skin lesions at presentation (P = 0·0854), and mode of initial treatment (P = 0·609) had no significant effect on the survival time. The results of this study suggest that primary CTCLs other than classical MF, SS, and CD30-positive lymphomas have a poor prognosis in most cases, and that the current classification may be a useful means of predicting the clinical behaviour in these lymphomas.     

Phenotypic analysis of peripheral T/NK cell lymphoma: study of 408 Japanese cases with special reference to their anatomical sites

The World Health Organization (WHO) classification of malignant lymphoma presented a list of disease entities well defined by clinical, immunological and genetic features. Therefore, the current diagnosis of peripheral T/NK-cell lymphomas (PTNKLs) essentially requires the inclusion of anatomical sites of disease and phenotypical features. We analyzed 408 Japanese cases of PTNKLs in order to clarify the relationship between anatomical sites of disease and phenotypical features and to translate the functional subsets of T and NK cells into their diagnoses for further understanding lymphomatic biology. The T/NK-cell lymphoma entities were allocated into three categories: (i) cytotoxic memory T-cell and/or NK-cell lymphoma (n = 151) consisting of extranodal NK/T-cell tumors other than mycosis fungoides (MF); (ii) non-cytotoxic memory T-cell lymphoma (n = 142) consisting of nodal and cutaneous tumors such as angioimmunoblastic T-cell lymphoma, adult T-cell lymphoma/leukemia and MF; and (iii) anaplastic lymphoma kinase positive anaplastic large cell lymphoma (n = 110) that has unique features and might be regarded as cytotoxic 'naive' T-cell lymphoma. Overall, these three categories were significantly correlated with age of onset, anatomical sites, the level of expression of cytotoxic molecules and CD45RO, and association with Epstein-Barr virus. This concept might provide a new insight enabling further understanding of the interrelationships among WHO T/NK-cell disease entities.     

Functional analysis of mononuclear cells infiltrating into tumors. VI. The effect of lymphocyte chemotactic factors on lymphocyte adhesion to endothelial cells.

We have analyzed mechanisms controlling infiltration of T lymphocytes into tumor tissues. A lymphocyte chemotactic factor-b (LMF-b) produced by tumor infiltrating CD4+ T lymphocytes was purified. LMB-b was specifically chemotactic for CD8+ T lymphocyte. Furthermore, LMF-b augmented lymphocyte adhesion to high endothelial venule (HEV) cells. The binding of CD8+ T cells to HEV cells was specifically augmented by LMF-b. The LMF-b primarily acted on T lymphocytes, whereas tumor necrosis factor as well as IFN-gamma acted on HEV cells or fibroblast cells. The binding of lymphocytes to fibroblast cell line was not augmented by LMF-b. The augmentation of lymphocyte adhesion to endothelial cells by LMF-b was mediated by the lymphocyte function associated antigen-1/intercellular adhesion molecule (LFA-1/ICAM) pathway, the CD2/LFA-3 pathway, and the very late antigen-4/culture supernatant-1 (VLA-4/CS-1) pathway.