Abnormalities in T cell interactions with the extracellular matrix proteins in a patient with Wegener's granulomatosis

Extracellular matrix of glioblastoma inhibits polarization and transmigration of T cells: the role of tenascin-C in immune suppression

Dense accumulations of T cells are often found in peritumoral areas, which reduce the efficiency of contact-dependent lysis of tumor cells. We demonstrate in this study that the extracellular matrix (ECM) produced by tumors can directly regulate T cell migration. The transmigration rate of several T cells including peripheral blood primary T cell, Jurkat, and Molt-4 measured for glioma cells or glioma ECM was consistently low. Jurkat cells showed reduced amoeba-like shape formation and delayed ERK activation when they were in contact with monolayers or ECM of glioma cells as compared with those in contact with HepG2 and MCF-7 cells. Phospho-ERK was located at the leading edge of migrating Jurkat cells. Glioma cells, but not MCF-7 and HepG2 cells, expressed tenascin-C. Knocking down the tenascin-C gene using the short hairpin RNA strategy converted glioma cells to a transmigration-permissive phenotype for Jurkat cells regarding ERK activation, transmigration, and amoeba-like shape formation. In addition, exogenous tenascin-C protein reduced the amoeba-like shape formation and transmigration of Jurkat cells through MCF-7 and HepG2 cell monolayers. A high level of tenascin-C was visualized immunohistochemically in glioma tumor tissues. CD3(+) T cells were detected in the boundary tumor area and stained strongly positive for tenascin-C. In summary, glioma cells can actively paralyze T cell migration by the expression of tenascin-C, representing a novel immune suppressive mechanism achieved through tumor ECM.

Enhanced T cells interactions with extracellular matrix proteins in infertile women with endometriosis

Essential features of endometriosis involve interactions with extracellular matrix (ECM). Recent data emphasize the important role of ECM proteins in the regulation of T cell function. The aim of this study was to determine activated T cell adhesion to ECM proteins in infertile women with endometriosis. Nine women with endometriosis diagnosed by laparoscopy according to the Revised American Fertility Society classification and ten normal healthy women with a previous successful pregnancy outcome were studied. We investigated phorbol acetate myristate (PMA) or phytohemaglutinin (PHA) activated peripheral blood T cell adhesion to the following proteins of ECM: collagen IV (C-IV), elastin (E) and fibronectin (Fn). In addition, CD4, CD8, CD29, CD45RO expression on peripheral CD3(+) T cells were studied using flow cytometry. We determine that PHA-activated T cell adhesion to C-IV and Fn are significantly higher in infertile women with endometriosis when compared to normal healthy women (P<0.05). No significant differences were noted in T cell's surface antigens expression between study groups. Our data suggest the existence of disturbed T cell-ECM interactions in infertile women with endometriosis. Further studies are needed to determine the role of these abnormalities in the pathogenesis of endometriosis.

Immune abnormalities in aneurysmal subarachnoid haemorrhage patients: relation to delayed cerebral vasospasm

Peripheral blood CD3+, CD19+, CD4+, CD8+ and CD45RO+ mononuclear cell subsets, T-cell proliferative responses to combinations of coimmobilized OKT3 antibody and an ECM protein (collagen I, collagen IV, fibronectin or elastin), and T-cell adhesion to collagen IV, fibronectin and elastin were studied in patients with aneurysmal subarachnoid haemorrhage. No significant difference was found in the major lymphocyte subsets between subarachnoid haemorrhage patients receiving no dexamethasone for brain oedema treatment and healthy blood donors. Compared with the latter, both the dexamethasone-untreated and -treated subarachnoid haemorrhage patients showed decreased relative proliferative responses of circulating T cells to OKT3 combinations with collagen IV and fibronectin, and an increased PHA-activated T-cell adhesion to elastin. CD45RO+, CD4+ and CD19+ peripheral blood cell subsets, CD4+/CD8+ cell ratio, PHA-activated T-cell adhesion to fibronectin and collagen IV, and OKT3-triggered T-cell costimulatory responses to elastin, collagen IV and fibronectin were significantly higher in subarachnoid haemorrhage patients presenting with delayed cerebral vasospasm (DCV) than in their DCV-free counterparts. The DCV-related differences in circulating lymphocyte subsets showed no apparent relationship to the glucocorticoid treatment, whereas the differences in the other indices were confined to the dexamethasone-untreated subarachnoid haemorrhage patients. The above results suggest that the CD4+/CD8+ ratio and T cell-ECM interactions play a role in the emergence of subarachnoid haemorrhage/DCV and may represent potential targets for subarachnoid haemorrhage therapy.

T cell interactions with extracellular matrix proteins in patients with thyroid-associated ophthalmopathy

Although thyroid-associated ophthalmopathy (TAO) is now generally accepted as an autoimmune inflammatory disorder of the extraocular muscles and the orbital connective tissue, its aetiopathogenesis remains poorly understood. Recent data indicate that impaired interactions between T cells and extracellular matrix (ECM) proteins may play an important role in development and maintaining of an inflammatory process. We report here results of the study focusing on interactions between T lymphocytes and collagen-I (Coll-I), collagen-IV (Coll-IV), fibronectin (FN), laminin (LM) in patients with TAO. Using a standard peripheral blood mononuclear cells (PBMC) proliferation assay, we observed a markedly enhanced T cell response to Coll-I in patients with active TAO (mean SI=4.5). The proliferatory response to Coll-I was significantly greater (Wilcoxon test; p < 0.001) than in normal subjects (mean SI=1.88), patients with stable TAO (mean SI=2.05) and patients with thyroid autoimmune diseases (AITD) without ophthalmopathy (mean SI=2.49). PBMC stimulation by Coll-I is likely to be antigen-dependent requiring engagement of the T cell receptor with collagen peptides, rather than mediated via integrins. The percentage of circulating CD29+ (beta1 integrin chain) T cells was not increased in patients with active TAO. Additionally in the assay of costimulation of CD3-mediated proliferation, we found that peripheral blood T cells from patients with TAO and AITD were costimulated only by FN. On the other hand a markedly enhanced costimulation of CD3-mediated proliferative responses by Coll-I, Coll-IV, FN and LM were observed in a retrobulbar T cell line. We conclude that abnormalities in T cell interactions with ECM proteins, especially Coll-I may play a role in the pathogenesis of TAO.

Depressed immune surveillance against cancer: role of deficient T cell: extracellular matrix interactions

Although T cells infiltrate malignant tumors, the local immune response is usually inefficient and tumors escape destruction. While extracellular matrix proteins strongly costimulate T cell responses in normal individuals, our studies indicate that peripheral blood T cells from cancer patients and tumor infiltrating cells respond poorly or are resistant to stimulative signals mediated by collagen I and IV and fibronectin. Moreover, the adhesive properties of cancer T cells are markedly depressed. Those functional deficiencies are paralleled by variable deficits in integrin and non-integrin T cell receptors for extracellular matrix. Immunotherapy with BCG causes a dramatic but transient increase in T cell: ECM interactions.