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R J Scheper

Publications and source records attributed to R J Scheper.

At least 181 records · Page 10Linked to original sources
PubMed1994

A new monoclonal antibody (3A5) that recognises a fixative resistant epitope on tissue macrophages and monocytes.

AIMS: To develop a monoclonal antibody specific for human macrophages in routinely processed material. METHODS: The monoclonal antibody was derived from a mouse popliteal lymph node after subcutaneous immunisation in the footpad with fragments of human spleen depleted of lymphocytes and erythrocytes. RESULTS: 3A5 is a monoclonal antibody reactive with macrophages, monocytes, and histiocytes in routinely processed (formalin fixed, paraffin wax embedded) human tissue specimens. Unlike the well known panmacrophage marker KP1 (CD68), neither dendritic cells (interdigitating cells, Langerhans' cells, and microglia) nor myeloid, lymphoid, or epithelial cells stained with 3A5. CONCLUSION: As the staining pattern of 3A5 is restricted, compared with other macrophage markers and the recognised epitope survives common fixation and embedding procedures, 3A5 is a valuable marker for histiocytes and macrophages in routine diagnostic applications.

Animals↗
PubMed1994

Immunohistological and functional analysis of adhesion molecule expression in the rheumatoid synovial lining layer. Implications for synovial lining cell destruction.

OBJECTIVE: It has previously been shown that the adhesion of lymphocytes to microvascular endothelium mediates lymphocyte extravasation within inflamed synovium. After passing the endothelial barrier, binding of lymphocytes to matrix proteins and synovial lining cells may further lead to synovial membrane hyperplasia and subsequent cartilage destruction. Thus, we have explored the molecular basis of T cell-synovial lining cell interaction in the synovial membrane of patients with rheumatoid arthritis (RA). METHODS: Using an immunohistochemical staining technique and an in vitro frozen section assay we studied the expression and the role of several adhesion molecules in T lymphocyte-synovial lining cell interaction in the inflamed synovial membrane. RESULTS: In RA the macrophage-like (type A) synovial lining cells express high levels of intercellular adhesion molecule 1 [ICAM-1 (CD54)], whereas the fibroblast-like (type B) synovial lining cells predominantly express vascular cell adhesion molecule 1 (VCAM-1), in addition to moderate levels of ICAM-1. Both cell types express low levels of fibronectin. Unstimulated and anti-CD3 stimulated peripheral blood T cells bear the respective ligands lymphocyte function associated antigen 1 [LFA-1 (CD18/11a)], and very late antigen 4 and 5 [VLA-4 (CD29/49d) and VLA-5 (CD29/49e)]. T lymphocytes predominantly bound to type B synovial lining cells. Inhibition studies with monoclonal antibodies revealed that this binding involves the VLA-4/VCAM-1 and VLA-5/fibronectin (FN), but not the VLA-4/CS1 pathway. LFA-1 is also involved in this interaction via its ligand ICAM-1. CONCLUSION: These results show that the molecular basis of T lymphocyte binding to rheumatoid synovial lining cells is different from that described for T lymphocyte binding to synovial membrane vascular endothelium which involves the VLA-4/VCAM-1 and VLA-4/CS-1 pathways, but not the LFA-1/ICAM-1 pathway.

Antibodies, Monoclonal↗
PubMed1994

Dendritic cells of the oral mucosa and the induction of oral tolerance. A local affair.

The oral mucosa is an important site to induce immunological tolerance to protein antigens. Previously we have established that oral contacts to allergen can lead to systemic tolerance in both humans and experimental animals. Because of the importance of tolerance induction as a possible way to modulate allergic reactivity, we wished to study the mechanisms involved in efficient tolerance induction via the oral mucosa. Dendritic Langerhans' cells in both skin and oral epithelium are the first cells to encounter antigen. Therefore, possible functional differences between Langerhans' cells from skin and oral mucosa were studied by migration and transfer experiments. It was found that dendritic cells derived from the oral mucosa were not able to transfer tolerance, but that they acted as antigen-presenting cells in sensu stricto irrespective of the source and route of antigen administration.

Animals↗
PubMed1994

Emergence of T-lymphocytes, eosinophils and dendritic cells in the bronchi of actively sensitized guinea pigs after antigenic challenge.

Bronchi from guinea pigs actively sensitized to ovalbumin and boosted two weeks later display increased numbers of CD4+ T-lymphocytes and eosinophils. We have further investigated immunopathological changes in sensitized guinea pigs 2 or 24 h after antigenic challenge with ovalbumin. Lungs were resected, frozen and cryostat sections stained with monoclonal antibodies that recognize relevant guinea pig epitopes. Cyanide-resistant peroxidase activity was used to stain eosinophils. No further increase in T-lymphocytes or eosinophils was observed 2 h after challenge. At 24 h, a marked increase in EPO+ eosinophils was found, and this was accompanied by severe mucosal damage characterized by epithelial shedding and ulceration. The numbers of T-lymphocytes remained stable but a novel population of cells with the appearance of dendritic cells was seen in the bronchial wall. They were negative for macrophage markers but were strongly Class II positive. These findings suggest that antigenic challenge results in further recruitment of eosinophils, their activation and release of toxic substances to the epithelium. Furthermore, other cell types, possibly dendritic cells, are attracted to the bronchi and could play a role in maintaining allergic inflammation via antigen presentation.

Animals↗
PubMed1994

Unimpaired immune functions after laparoscopic cholecystectomy.

BACKGROUND: The advantages of laparoscopic cholecystectomy over the open procedure seem to be related to the lesser surgical trauma. Whether this is also reflected by reduced postoperative immune suppression is not known. METHODS: The perioperative cellular immunocompetence of patients undergoing either laparoscopic (n = 8) or open (n = 8) cholecystectomy was evaluated before operation and at 24 hours and 6 days after operation for inflammatory reactivity by white blood cell counting and serum interleukin-6 assessment. Immunocompetence was evaluated by skin testing with phytohemagglutinin and by phenotyping blood mononuclear cells. RESULTS: Although 24 hours after conventional cholecystectomy granulocyte and interleukin-6 levels were strongly increased, laparoscopic cholecystectomy did not affect these acute inflammation parameters. Patients who had undergone conventional cholecystectomy showed a strong reduction of phytohemagglutinin responsiveness, in contrast to laparoscopic patients (67% versus 0% reduction). Flow cytometric analysis of blood mononuclear cells revealed a distinct reduction of HLA-DR expression on monocytes in the open cholecystectomy group only. Both parameters returned to baseline levels within 6 days after operation. CONCLUSIONS: In contrast to open cholecystectomy, laparoscopic cholecystectomy does not significantly affect parameters reflecting immunocompetence. This lack of interference with cellular immune functions provides another argument favoring laparoscopic rather than open cholecystectomy.

Adult↗
PubMed1993

Overexpression of a M(r) 110,000 vesicular protein in non-P-glycoprotein-mediated multidrug resistance.

A M(r) 110,000 protein (p110) is overexpressed in P-glycoprotein-negative multidrug-resistant tumor cell lines of different histogenetic origins. These cell lines show an ATP-dependent drug accumulation defect, suggesting the presence of drug transporter molecules different from P-glycoprotein. Immunohistochemical staining with a p110-specific monoclonal antibody (LRP-56) showed that, like P-glycoprotein, the molecule has a high expression in normal epithelial cells and tissues chronically exposed to xenobiotics and potentially toxic agents, such as bronchial cells, cells lining the intestines, and kidney tubules. Staining of LRP-56 is primarily cytoplasmic, in a coarsely granular fashion, indicating that it reacts with a molecule closely associated with vesicular/lysosomal structures. Involvement of p110 in the energy-dependent drug transport process present in the cell lines is unknown.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Delayed-type hypersensitivity reactions to tumor-associated antigens in colon carcinoma patients immunized with an autologous tumor cell/Bacillus Calmette-Guérin vaccine.

Five different colon tumor-associated antigens (CTAA) were tested for their ability to induce an immune response in vivo and in vitro in ten colon carcinoma patients immunized with an irradiated autologous tumor cell/Bacillus Calmette-Guérin vaccine (active specific immunization) after resection of the primary tumor. The CTAA were defined by two different human monoclonal antibodies (MCA 1688 and MCA 28A32) derived by immortalization of peripheral blood B-lymphocytes from an active specific immunization patient. Delayed-type cutaneous hypersensitivity responses against a mixture of CTAA 28A32-50K and -32K were positive in seven of ten patients tested. In vitro T-cell responses upon stimulation with CTAA 28A32-32K were found to be positive in seven of ten patients and correlated with delayed-type cutaneous hypersensitivity responses to the antigen mixture. These data suggest that CTAA 28A32-32K might contain an important tumor-related T-cell epitope. Moreover, this method is suitable to define potential future candidates for antitumor vaccine development.

Animals↗
PubMed1993

P-glycoprotein expression in human plasma cell myeloma: correlation with prior chemotherapy.

Multidrug-resistant (MDR) myeloma patients failing chemotherapy may express P-glycoprotein (PGP), which serves as an efflux pump protecting the neoplastic cells. Unknown is whether PGP expression might relate to prior cytotoxic drug exposure. To address this question, we studied 106 consecutive bone marrow samples from 104 myeloma patients with samples studied either before or after therapy and at the time of relapse. We performed an established immunocytochemical assay of PGP using an MDR-1-specific monoclonal antibody and correlated PGP status with prior chemotherapy dosage. Myeloma patients with no prior therapy had a low incidence of PGP expression (6%, 3/47), whereas those receiving chemotherapy had a significantly higher incidence (43%, 21/49) (P < .0001). A substantially higher incidence of PGP expression (50%, 83%, respectively) occurred when the total vincristine dose exceeded 20 mg and when doxorubicin exceeded 340 mg. In the 11 patients who received both high vincristine and doxorubicin dosages (> 20 mg, > 340 mg total dose) there was 100% incidence of PGP expression in the tumor cells. These data provided the basis for a predictive mathematical model from which dose-related PGP expression normograms were generated. Time with myeloma for PGP-negative patients (mean 33 months) had overlapping confidence limits with PGP-positive patients (mean 42 months), suggesting that disease duration was not a significant variable. PGP expression did not correlate with other clinical factors or immunophenotypic factors. Our findings indicate a strong correlation between PGP expression in myeloma and past chemotherapy in myeloma, in particular, related to prior exposure to the natural product agents vincristine and doxorubicin. Additionally, the proportion of PGP-positive plasma cells was significantly higher in the doxorubicin-treated patients than the nondoxorubicin-treated patients (87.7% v 65.17%; P = .013). Combined high vincristine and doxorubicin total dosage appear highly predictive of PGP expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Monoclonal antibody 4C7 recognizes an endothelial basement membrane component that is selectively expressed in capillaries of lymphoid follicles.

In order to define compartment-related structures within the extracellular matrix of human lymphoid organs, monoclonal antibodies (MAbs) were generated by immunizing mice with stromal fragments of human tonsils. One MAb (4C7) was selected which recognized an endothelial basal membrane component that is selectively expressed in capillaries of lymphoid follicles. The epitope was also present in follicles within chronically inflamed synovial membrane and in a hyperplastic thymus of a patient with myasthenia gravis. B-cell non-Hodgkin's lymphomas with a follicular growth pattern expressed the antigen in neoplastic follicles, whereas diffuse growing lymphomas lacked the antigen. The restricted distribution pattern suggests involvement of the 4C7-defined antigen in the organization of the follicular compartment within human lymphoid tissue.

Antibodies, Monoclonal↗
PubMed1993

Efficient expansion of tumor-infiltrating lymphocytes from solid tumors by stimulation with combined CD3 and CD28 monoclonal antibodies.

Combined CD3 and CD28 monoclonal antibodies (mAb) may initiate efficient activation and expansion of tumor-infiltrating lymphocytes (TIL). In this study we compared phenotypical and functional characteristics of TIL from a group of 17 solid human tumors, stimulated either by high-dose recombinant interleukin 2 (rIL-2, 1000 IU/ml) or by a combination of anti-CD3 and anti-CD28 monoclonal antibodies in the presence of low-dose rIL-2 (10 IU/ml). Compared to activation with high-dose rIL-2, stimulation of TIL with CD3/CD28 mAb induced significantly stronger proliferation and yielded higher levels of cell recovery on day 14. Following the CD3/CD28 protocol, expansion of an almost pure population of CD3+ cells was obtained. Whereas CD4+ cells dominated in the first week of culturing, within 4 weeks the CD8+ population increased to over 90%. The specific capacity to kill autologous tumor cells was not increased as compared to the high-dose rIL-2 protocol, but all cultures showed high cytotoxic T cell activity as measured in a CD3-mAb-mediated redirected kill assay. These studies show that combined CD3 and CD28 mAb are superior to rIL-2 with respect to the initiation of expansion of CD8+ cytolytic TIL from solid tumors. Stimulation with specific tumor antigens at a later stage of culturing may further augment the expansion of tumor-specific cytolytic T cells.

Antibodies, Monoclonal↗
PubMed1993

Oral induction of tolerance to nickel sensitization in mice.

Antigen contact via the alimentary tract prior to sensitization may result in systemic immunologic unresponsiveness ("oral tolerance"). The induction of oral tolerance seems an attractive strategy to combat undesired immune responses, such as allograft rejection and autoimmune and allergic diseases. We describe clear and reproducible sensitization to nickel in mice reared under nickel-free conditions. Hypersensitivity was induced by injecting nickel sulfate intradermally into the flank skin and elicited by injecting the metal salt into the pinnae of the ears. The effectiveness of orally induced hyporesponsiveness could be inferred from a low degree of hypersensitivity obtained with mice raised and maintained in cages with nickel-releasing covers and water nipples. This mouse model for the assay of nickel hypersensitivity was used for oral tolerance studies by administrating non-toxic doses of nickel sulfate in drinking water or intragastrically prior to sensitization. In these animals, the development of delayed-type hypersensitivity was suppressed in a dose-dependent way, and the hyporesponsiveness could be transferred by CD8+ cells. The antigen specificity of this oral tolerance could be demonstrated by the concomitant use of sensitization and challenge procedures for nickel and chromium. The hypersensitivity assay described provides a versatile, highly reproducible experimental model to study immunoregulation of oral tolerance to clinically relevant metal allergens.

Administration, Oral↗
PubMed1993

Role of the CS1 adhesion motif of fibronectin in T cell adhesion to synovial membrane and peripheral lymph node endothelium.

OBJECTIVES: It has previously been shown that the very late antigen-4/vascular cell adhesion molecule-1 (VLA-4/VCAM-1) pathway functions as a receptor/ligand interaction system mediating the recruitment of activated lymphocytes to inflamed synovium of patients with rheumatoid arthritis. This study was performed to determine whether VLA-4 also affects lymphocyte adhesion to inflamed synovium through interaction with the alternatively spliced CS1 domain of fibronectin. METHODS: The effect of the synthetic peptide CS1 on lymphocyte binding to human synovial and peripheral lymph node high endothelial venules (HEVs) was measured in an in vitro frozen section assay. RESULTS: In the presence of the CS1 peptide or antibody to fibronectin, significant inhibition of binding was observed (54 and 51% respectively). Blocking with antibody to VCAM-1 yielded inhibition of binding to 46% of the control value. Maximum inhibition of binding was obtained with a combination of antibody to VCAM-1 and CS1 (65%) and with antibody to VLA-4 alpha (68%). Blocking the classical fibronectin receptor with antibody to VLA-5 alpha gave a slightly lower inhibition at 42%. In normal peripheral lymph nodes, the synthetic peptide CS1 and antibodies to fibronectin and VLA-5 also partially inhibited T cell binding to HEVs (45, 47, and 52% respectively). CONCLUSION: These results show that fibronectin mediates lymphocyte-HEV interactions not only through its classical VLA-5 receptor, but also through its CS1 adhesion motif in inflamed synovium and peripheral lymph nodes.

Arthritis, Rheumatoid↗
PubMed1993

Immunopathologic alterations in the bronchi of immunized guinea pigs.

Isolated lungs from guinea pigs actively sensitized to ovalbumin and boosted 2 wk later display an enhanced bronchoconstriction and release larger amounts of secondary mediators as compared with lungs from nonimmunized animals when stimulated by platelet-activating factor or other agonists. We have investigated changes in T lymphocytes and eosinophils found in the bronchial wall of immunized and nonimmunized guinea pigs. The animals received two injections of 10 micrograms ovalbumin in Al(OH)3, at a 2-wk interval. Two studies were performed: (1) the animals were killed 7 days after the booster injection of antigen, (2) they were challenged with ovalbumin at this same day and killed after 2 or 24 h. Lungs were resected and frozen, and cryostat sections stained using monoclonal antibodies that recognize T cells, T cell subsets, or other relevant epitopes. Cyanide-resistant peroxidase activity was used to identify eosinophils. A large number of T cells, mainly of the CD4+ subset, and eosinophils were recruited into the bronchi 7 days after the booster injection of the antigen, compared with nonimmunized or nonboosted animals. In antigen-challenged animals, the numbers of T cells did not change but eosinophils were further increased in number at the 24 h time point. Also at this time point, a population of cells with a dendritic appearance was seen in the bronchial wall, which did not express macrophage markers but was strongly class II positive. Class II positivity was also noted in the bronchial epithelium and on many cells infiltrating the mucosa. These findings suggest that activated T cells and/or their products play an important role in the bronchopulmonary immunopathology associated with this model and possibly with the development of bronchial hyperreactivity.

Animals↗
PubMed1992

An immunosuppressive retrovirus-derived hexapeptide interferes with intracellular signaling in monocytes and granulocytes through N-formylpeptide receptors.

We have previously found that the retroviral p15E-derived hexapeptide LDLLFL is a potent inhibitor of the FMLP-induced polarization response that is an early event in chemotaxis of monocytes and granulocytes. We investigated the mechanism of action of LDLLFL. LDLLFL inhibited the changes in [Ca2+]i in response to FMLP, but not to C5a or leukotriene B4. The reverse peptide LFLLDL was not inhibitory. In the presence of LDLLFL, the FMLP dose-response curve shifted to higher concentrations, indicating that LDLLFL interfered with binding of FMLP to its receptor. Indeed, binding of [3H]FMLP to neutrophilic granulocytes was inhibited in the presence of LDLLFL. Furthermore, immunosuppressive LDLLFL homologs also inhibited binding of FMLP to granulocytes, whereas noninhibitory LDLLFL homologs did not. Our results suggest that retroviral p15E and p15E-like factors, which can be found in serum of patients with cancer or chronic upper airway infections, may interfere with the interaction of N-formylpeptides derived from (opportunistic) bacteria, with monocytes and granulocytes. This receptor interference may impair monocyte and granulocyte reactivity toward these agents.

Amino Acid Sequence↗
PubMed1992

Locoregional administration of etoposide, but not of interleukin 2, facilitates active specific immunization in guinea pigs with advanced carcinoma.

Using a guinea pig line 10 hepatocellular carcinoma model for advanced metastatic disease, we studied the therapeutic effect of local cytotoxic drug treatment at the tumor site as compared to, and in combination with, active specific immunization. In addition, locoregional treatment with interleukin 2 (IL-2) was studied. Intratumoral administration of the cytotoxic drug etoposide (VP-16), but not of IL-2, when started in a late stage of tumor growth and continued for 3 wk, caused full regression of all intradermally implanted tumors and cured a small number of animals (14%). When the primary tumor was removed at the onset of treatment, administration of VP-16 and, to a lesser degree, IL-2 at the former tumor site led to improvement of cure rates (up to 30%). Complete cure always coincided with the induction of antitumor immunity. Since both VP-16 and IL-2, when locally administered, strongly augment T-cell-mediated immune responses, the observed therapeutic effect was partially attributed to potentiation of a T-cell-mediated antitumor response. Active specific immunization (ASI) using viable irradiated tumor cells admixed with Bacillus Calmette-Guérin also aims at induction of specific antitumor immunity. In late-stage disease, ASI alone induced cure rates of 39%. Combination of ASI with local cytotoxic drug treatment, but not with locoregional administration of IL-2 at the former primary tumor site, led to very high cure rates (up to 78%). Cured animals were always resistant to a second challenge with line 10 tumor cells. Routinely, one systemic injection with cyclophosphamide was given at the start of all treatment protocols. Omission of CY strongly reduced the cure rates obtained with ASI and locoregional VP-16 treatment. The high cure rates likely relate to the fact that locally administered cytotoxic drugs are capable of reversing immune tolerance, besides exerting direct antitumor action within tumor-draining lymphoid tissues. The present results therefore support our view that local cytotoxic drug treatment should be further explored for its incorporation in antitumor therapies such as ASI, aiming at maximal clinical benefit and minimal toxicities.

Animals↗
PubMed1992

In vitro response of human small-cell lung-cancer cell lines to chemotherapeutic drugs; no correlation with clinical data.

Three cell lines derived from small-cell lung carcinoma (SCLC) tumors of patients who had no clinical response after treatment with a multi-drug regimen were compared to 3 cell lines derived from tumors of patients who, upon treatment, showed a complete clinical response. These 2 groups of cell lines were considered to represent the in vitro counterparts of the 2 extremes of the clinical spectrum of sensitivity for chemotherapeutic drugs in small-cell lung cancer. To assess whether the in vivo (in)sensitivity of a tumor to a certain drug regimen is retained in vitro, the cell lines were tested for drug sensitivity using the microtiter-well tetrazolium assay and the results were compared with the in vivo data. No correlation was found. Since in vitro models using cell lines are based on the assumption that a cell line reflects the properties of the tumor from which it is derived, several additional parameters such as MAb staining against different SCLC-associated antigens and DNA content were analyzed in the biopsies and the cell lines. The results showed that selection of discrete tumor-cell populations in vitro occurs. Results of in vitro chemosensitivity testing for individual SCLC patients should be interpreted with caution.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Drug-transporter proteins in clinical multidrug resistance.

Upon exposure to chemotherapeutic drugs, mammalian cells can acquire resistance to structurally and functionally unrelated compounds, a property known as multidrug resistance (MDR). One MDR mechanism, i.e. by the overexpression of a plasma membrane protein, P-glycoprotein (P-gp), has been identified at the molecular level. The mdr1 gene-encoded P-gp acts as a drug efflux pump, lowering intracellular drug concentration by active extrusion of drugs from the cell. The role of P-gp in determining clinical resistance to multiple anticancer drugs is likely to be largely different for various tumor types. Recently we selected a monoclonal antibody (mAb LRP56) for strong, granular cytoplasmic reactivity with MDR tumor cell lines without P-gp (over)expression. None or weak reactivity was observed with parental and P-gp positive cell lines. We hypothesize that as yet-undefined drug transport-mediating proteins are inserted in intracellular membranes lining the exocytotic compartment and thus may contribute to clinical multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗