Modulation of extracellular matrix receptors (integrins) on human endothelial cells by cytokines.
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Biomedical subjects
Publications and source records attributed to M Geuna.
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Pretreatment of acute myeloblastic leukemia cells with the hemopoietic growth factor interleukin 3 (IL3) increased their susceptibility to lymphokine activated killing (LAK) but did not affect their constitutive resistance to native natural killer activity. In addition, IL3 treatment did not alter the LAK cell-mediated killing of CD34+ hemopoietic progenitors present in normal bone marrow. Increased 3H-thymidine uptake was generally observed after IL3 treatment. However, failure to proliferate in response to IL3, observed in some cases, did not prevent changes in LAK susceptibility. Enhanced lysis of IL3-treated leukemic cells was accompanied by a moderate increase of the effector-target binding. Increased LAK susceptibility was already observed at 18 h, while optimal cytolysis and expression of the cell adhesion molecule (CAM) LFA-3 (CD58) by IL3-treated AML cells were concomitantly observed at later culture times. In contrast, the CAM ICAM-1 (CD54) was not modulated by IL3, nor were significant changes in the expression of either CAMs observed in normal hemopoietic cells. Blocking experiments with the anti-CD58 monoclonal antibody demonstrated a variable neutralizing effect on the IL3-induced increase of LAK activity, depending on the leukemia cell studied. The effect described here, together with the known role of IL3 in normal hemopoiesis makes it a factor of potential therapeutic value for the treatment of leukemic patients.
The murine monoclonal antibody (MoAb) NL07 was generated by immunization with human platelet extracts. NL07 MoAb recognized a molecule expressed by human platelets, monocytes, and endothelial cells, as well as by the myelomonocytic line U937 and by some melanoma cells or lines. Normal endothelial cells and the melanoma cells express the NL07 epitope only while adhering to a substrate. SDS-polyacrylamide gel electrophoresis and two-dimensional gel analysis indicate that the molecule recognized by NL07 MoAb on platelets is a single chain structure featuring a molecular weight of 85 kDa under reducing conditions, with an acidic isoelectric point ranging from 5.2 to 5.5. The specific phenotype distribution and the biochemical structure indicate that NL07 MoAb recognizes the platelet GPIV (CD36) molecule, a surface glycoprotein with a functional role of thrombospondin receptor. The results of competition tests with OKM5 MoAb (specific for the CD36 molecule) confirm the molecular specificity and epitope coincidence. Furthermore, upon binding to the platelets, NL07 MoAb is able to transmit via CD36 an activation signal which is followed by a potent aggregation. On the contrary, there is lack of evidence concerning the ability of the CD36 molecule of transmitting signal(s) on the U937 cells.
The effectiveness of "standard" lymphokine-activated killer (LAK) cells, recovered after 6 days, and of "standard" adherent LAK (A-LAK) cells, recovered after 14 days of culture in the presence of recombinant interleukin-2 (rIL-2) from peripheral blood lymphocytes of 21 healthy donors, was assessed through comparison of their proliferation, surface markers, cytotoxic activity, lymphokine production, and antitumor activity. In the presence of rIL-2, plastic adherent precursors of A-LAK cells proliferated much better than those of "standard LAK" cells and expanded even more than 300-fold. However, the final cell recovery of A-LAK was always lower because of their very few precursors, and the total lytic units (LUs) generated in A-LAK cultures were always lower for the same reason. On the other hand, the lytic activity of each A-LAK cell was always higher than that of a LAK cell. This was particularly evident on day 6 of culture. Removal of nonadherent cells after the first 24 h culture resulted in a significant enrichment in CD3-CD56+ and CD8+CD56+ cells in A-LAK cells, with a marginal number of CD4+ cells. A significant direct correlation between LUs and A-LAK CD3-CD56+ percentage was found. In the presence of rIL-2, A-LAK cells produced higher amounts of tumor necrosis factor-alpha and interferon-gamma than LAK cells, while only A-LAK cells produced IL-1 beta and small amounts of IL-4. Neither LAK nor A-LAK produced IL-2. In the absence of injections of IL-2, LAK and A-LAK cells were equally able to inhibit the growth of a human T-cell lymphoma in immunosuppressed nude mice.
The structure of the CD38 molecule has been evaluated by one- and two-dimensional gel analysis and by enzymatic digestions. The source of the Ag was mainly membrane preparations obtained from MLC cells, from normal thymocytes, and from the plasmocytoma line LP-1. Membranes were solubilized in NP-40 and the extracts fractionated by immunoaffinity chromatography [using a specific anti-CD38 antibody (A10 mAb) covalently linked to Sepharose protein A]. The purified Ag migrated as a single chain of Mr = 45,000 not associated with beta 2-microglobulin. Two-dimensional IEF gel electrophoresis revealed five spots (isoelectric point (pI) range: 6.5 to 6.9). After neuraminidase treatment, the mobility of the five polypeptides shifted to a more basic pI. Endoglycosidase-H treatment reduced the Mr of CD38 by 20%, revealing a broader band centered at Mr = 36,000. Treatment of CD38 molecule with V8 Staphylococcus aureus protease yielded a single dominant band at Mr = 38,000 which was still reactive with A10 mAb. The CD38 molecular was trypsin-resistant in both denatured or native conditions. These results clearly show the glycoprotein nature of CD38 molecule, which includes 2 to 4 N-linked oligosaccharide chains containing sialic acid residues. Furthermore, the present data indicate that the CD38 molecule does not display an apparent biochemical polymorphism among the different CD38+ cells or lines.
The phenotype of the lymphoid cell component of 35 thymomas was investigated by analyzing cryostat sections and lymphocyte suspensions. The morphology in each case was determined by examining multiple tissue samples from different parts of the tumor. Structural heterogeneity was shown in 14 thymomas, and a homogeneous morphology of cortical or medullary or mixed types in the others. To assess whether this heterogeneity was correlated with differences in the lymphoid phenotype, we analyzed both lymphocyte suspensions and frozen sections from the same samples. Phenotypical differences in the suspensions of each thymoma in the heterogeneous group were noted and similar differences were also observed in the cryostat sections. Phenotypical abnormalities were found in some thymomas. They consisted of the simultaneous expression of cortical and medullary markers, which was most marked in the heterogenous mixed-type thymomas invading the lung. Furthermore, the global phenotype was tested on a pool of lymphocyte suspensions in all thymomas. This procedure distinguished cortical, medullary and intermediate cortico-medullary immunophenotype models which closely correlated with the tumor histology. It was concluded that, due to the frequent structural and immunological heterogeneity of thymomas, correct assessment of their lymphoid component requires a two-step analysis. This comprises: 1) individual suspensions from samples taken from different areas of the same thymoma, and 2) a pool of these suspensions. The first step will reveal the different immunological characteristics. In the second, the lymphocyte phenotype, which may vary widely throughout the tumor, will be represented in its totality. These findings may be of great help in predicting clinical patterns, especially possible malignant evolution.
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The lymphoid tissue of the human fetal spleen at various stages of gestation was studied on frozen and paraffin sections and with two-colour flow cytometry. On the sections scattered lymphoid cells and perivascular lymphoid aggregates were found starting from the 15th week of gestation. CD3, CD5, CD19, CD20, CD21, CD22, CD24, CD35, CD38-positive cells were observed. No CD10- and CD23-positive cells were detected. Flow cytometry showed a prevalence of B-lymphocytes. The majority of them expressed CD5 antigen. These cells were also IgM/D, CD19, CD20, CD21, CD22, CD24 and CD35-positive. Only few of them expressed CD10 and CD23. A similar phenotype was found in human cord blood. By contrast, in adult spleens CD5 B-cells never exceeded 8% of the B-cells. The comparison between CD5 B-cells of fetal spleen and CD5 B neoplastic cells of 72 cases of small B-cell lymphomas showed that CD23, which was usually expressed by a high percentage of the neoplastic cells, particularly in B-CLL, was not displayed by the majority of the CD5 non neoplastic cells. The reverse was shown by CD35. These findings suggest that different states of activation distinguish the normal CD5 B-cells from their malignant counterpart.
Nine patients with squamous cell carcinoma of the oral cavity and oropharynx underwent preoperative perilymphatic administration of recombinant interleukin 2 (rIL-2). A more marked eosinophil and lymphocyte infiltration and more extensive edema than in 13 untreated cases were observed in surgical specimens. Necrosis was present in five of nine cases, but involved no more than 10% of the neoplastic tissue; in three of nine cases, characteristic necrotic changes with intense eosinophil infiltration possibly induced by lymphokines involved the peritumoral soft tissues. Of the tumor-infiltrating lymphocytes, T-lymphocytes (mostly CD4+ cells) prevailed over B-lymphocytes. CD4+ and CD8+ cells were mainly located close to the neoplastic sheets. Moderate amounts of CD38+ and CD11c+ cells (macrophages) and few CD16+ and CD56+ lymphocytes were found in all cases. CD25+ and LAK1+ cells were significantly more numerous in treated than in untreated cases. This suggests that local administration of rIL-2 induces an increase in activated T-lymphocyte subsets infiltrating the neoplastic tissue, thus eliciting a tumor-specific T-lymphocyte reactivity.
The murine monoclonal antibody (mAb) CB43, raised against the K-562 erythroleukemia line, reacts with monocytes, tissue macrophages, thymocytes and with all the human lines tested but not with resting lymphocytes, large granular lymphocytes, granulocytes and erythrocytes. However, activated lymphocytes and natural killer cells express the CB43 antigen. Embryonic and fetal fibroblasts are positive, while adult fibroblasts are negative. Proximal convoluted tubules in kidney, epithelial cells in esophagus and breast, and sarcolemma in skeletal muscle are reactive with mAb CB43. This antibody can also bind to isolated guinea pig cardiac myocytes, and, furthermore, can induce a transient inotropic effect on isolated atria. The reactivity with different cell and tissue types and the functional effects of the CB43 mAb were reminiscent of the 4F2/44D7 antibodies, shown previously to block Na+/Ca2+ exchange in heart and skeletal muscle. Co-immunoprecipitation studies with CB43 and 44D7 mAb, using radiolabeled Daudi cells, revealed co-migration of polypeptides of 87 and 38 kDa. However, the epitope recognized by CB43 is not present on the human heavy chain which bears the 44D7/4F2 epitope as demonstrated by the lack of reactivity of CB43 mAb with mouse L cells transfected with the 4F2 heavy chain gene. Thus, CB43 represents a newly described epitope present on the human light chain or dependent on the conformation of the human dimer.
Twenty-six human thymomas were studied in an attempt to correlate their morphological appearance with the type and degree of T-lymphocyte maturation, as determined by acid alpha-naphthyl-acetate esterase (ANAE) activity and immunological analysis. Four normal human thymuses were used for purposes of comparison. Two morphological patterns were identified in the thymomas. The distinction was based largely on similarities between the neoplastic epithelial cells and normal cortical and medullary epithelial cells, and on the relative proportions of epithelial cells and lymphocytes. By these criteria "medullary" and "cortical" patterns were identified. In several thymomas both patterns were present in the same tumor ("mixed-type pattern"), producing alternating dark cortical-like areas and lighter foci of medullary differentiation. A good correlation was found between the two patterns and the phenotype of the T-associated lymphoid component. ANAE activity, which was completely lacking in normal cortical thymocytes, was almost absent in the phenotypically immature T-cells of cortical-type thymomas. By contrast, in the medullary-type thymomas, T-cells showed immunological features in common with medullary thymocytes. This was characterized by strong ANAE activity in the majority of cells with a staining pattern corresponding to that of peripheral T-lymphocytes. In addition, most of the proliferating epithelial cells in medullary-type thymomas stained strongly with anti-cytokeratin and anti-epidermal-type keratin antisera. In the mixed-type thymomas the epithelial cell morphology and the immunohistochemical and enzymic features of the T-cells were found to be closely related to the respective cortical--or medullary-like areas. It was concluded that the various characteristics of normal thymic cortex and medulla studied are also present in thymomas. In particular, in medullar-type thymomas the presence of many of the features of normal thymic medulla, such as a squamous cell component, macrophages and interdigitating reticulum cells, may constitute a microenvironment which operates actively in T-cell education. This may account for the functional activities, characteristic of peripheral T-lymphocytes, which T-lymphocytes attain in these thymomas.
We have studied the effect of recombinant (r)-Prl on the in vitro-induced MHC-unrestricted cytotoxicity of NK and T cells. A 4-day treatment with r-Prl in serum-free medium enhanced the cytotoxicity of NK cells to the NK-susceptible cell lines K562 and U937, but did not induce de novo NK cytotoxicity in T lymphocytes. By contrast, development of cytotoxicity against the LAK-susceptible cell lines HL60, Jurkat, Daudi and Supt-1 occurred in both NK and T cells. The effect of r-Prl on NK cells was bi-phasic with peaks at 25 ng/ml (1.2 nM), the upper physiological level, and 200 ng/ml (9.6 nM). By contrast, LAK activation of T cells only occurred at the highest r-Prl concentration. In addition to its intrinsic stimulatory activity, r-Prl was also capable of modulating in a dose-dependent manner distinct stages of the IL2-driven LAK/T differentiation pathway. Physiological concentrations of r-Prl interacted with low doses r-IL2 to significantly enhance generation of NK- and T-LAK activities. By contrast, pathological concentrations had opposite effects on generation of optimal LAK response, depending on the kind of LAK progenitor. The T-derived LAK activity was reversibly inhibited at the effector level, while the mature NK-LAK cells were stimulated. These data confirm our previous findings of a co-operative effect of Prl and IL2 on NK cell proliferation and reinforce the view that the signals conveyed by the two factors may be functionally related.
Gastric cancer is often associated with p53 over-expression and Helicobacter pylori (HP) infection. In this study we have investigated the production of the p53 protein and mutation of its gene in precancerous gastric lesions with HP infection. For this purpose 130 patients who underwent endoscopy for dyspepsia were enrolled in the study. To assess p53 production and mutation of the p53 gene we employed an immunoluminometric assay and polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) analysis, respectively. Histologically, 52 of the 130 enrolled patients showed intestinal metaplasia type I (IM) (90.4% of these were also HP positive), 47 had HP-related gastritis and 31 were normal. p53 cytosol levels were significantly higher in patients with IM or HP-related gastritis than in normal patients (p = 0.0137 and p = 0.0411, respectively). All DNAs extracted from gastric mucosa samples with higher p53 values and examined for p53 mutations by PCR-SSCP analysis were characterized by a normal run. Our data indicate, that irreversible genetic changes in the p53 protein has not yet occurred in morphologically non-neoplastic gastric mucosa with IM and HP-related chronic gastritis. In conclusion, the increase in p53 cytosolic levels found in our study is due to an increased production of the wild-type protein probably related to an inflammatory response induced by HP infection.
BACKGROUND: In the last few years many studies have been published on GM-CSF receptors, focusing on molecular structure, function and distribution. Nevertheless, protocols for detecting GM-CSF receptors on formalin-fixed paraffin-embedded histological sections, to our knowledge, have not been described. METHODS: A method based on non-isotopic in situ hybridization (ISH) using a 21-base antisense DNA oligoprobe whose 3'-end was labeled with digoxigenin 11-dUTP was devised. The probe was applied on 20 routinely processed bone marrow trephine biopsies which were considered as positive controls. RESULTS: The hybridization signal was seen in myeloid cells, erythroid progenitors and rare megakaryocytes. CONCLUSIONS: Non-isotopic ISH represents an alternative to current methodologies for the assessment of GM-CSF receptor expression; since it is suitable for routinely processed samples, it can be regarded as a helpful tool for diagnostic determination of GM-CSF receptors in tumors from patients receiving GM-CSF and for retrospective studies on archival material.