Search PubMed⌕ Search

Biomedical subjects

R J Scheper

Publications and source records attributed to R J Scheper.

At least 199 records · Page 11Linked to original sources
PubMed1992

Expression and characterization of two differentiation antigens in human stratified squamous epithelia and carcinomas.

Using viable cells of a human squamous-cell carcinoma (SCC) cell line as immunogen, we generated 2 monoclonal antibodies, MAbs K984 and K928, to SCC surface antigens. Immunoperoxidase staining of frozen sections of normal epidermis revealed that MAb K984 reacts with the poorly differentiated basal cells, while MAb K928 is reactive with the more highly differentiated suprabasal cells. A similar complementary reaction pattern of these antibodies was demonstrated in the majority of well-differentiated human tumors and some moderately differentiated SCCs. In contrast, simultaneous reactivity of MAb K984 and K928 was found for the majority of cells within other well- and moderately differentiated SCCs, as well as all poorly differentiated SCCs. Further biochemical characterization indicated that the antigen recognized by MAb K984 is similar to the one recognized by MAb SF-25. MAb K928 recognizes a 50- to 55-kDa molecule under non-reducing conditions. Antibodies with similar features to MAb K928 have not been described previously. The antigens recognized by MAbs K984 and K928 can be regarded as novel markers associated with cellular maturation in squamous epithelia. The antigen detected by MAb K984 is probably associated with the proliferating fraction in SCCs.

Antibodies, Monoclonal↗
PubMed1992

Suppression of lymphocyte proliferation by a retroviral p15E-derived hexapeptide.

CKS-17 (LQNRRGLDLLFLKEGGL), a synthetic peptide derived from a conserved region of retroviral transmembrane proteins, has previously been shown to suppress several different immune effector mechanisms. The present study was undertaken to further delineate immunosuppressive site(s) of CKS-17. Overlapping hexapeptides covering the complete sequence of CKS-17 were synthesized. One CKS-17-derived hexapeptide, LDLLFL, suppressed ligand [CD3, interleukin (IL)-2]-induced lymphocyte proliferation. Spontaneous proliferation of transformed lymphoid cell lines, as well as cell lines from myeloid or epitheloid origin, was not inhibited by LDLLFL. Full suppression required the continuous presence of LDLLFL during culturing, and did not involve interference with monocyte function. Radiolabeling studies showed that the hexapeptide did not compete with IL-2 for IL-2 receptor binding. Most likely the LDLLFL motif interferes with steps shared by the IL-2 and CD3 receptor-induced signaling pathways. Since LDLLFL displays multiple immunosuppressive activities, it may constitute a biologically relevant immunosuppressive site of retroviral transmembrane proteins.

Animals↗
PubMed1992

Synthetic hexapeptides derived from the transmembrane envelope proteins of retroviruses suppress N-formylpeptide-induced monocyte polarization.

Retroviral infections are frequently associated with immunosuppression. Retroviral transmembrane envelope proteins (TM proteins) play an important role in this phenomenon. CKS-17, a synthetic heptadecapeptide, represents the immunosuppressive site of these retroviral TM proteins. Here we support on the further delineation of this immunosuppressive site using CKS-17-derived hexapeptides. The N-formyl-methionyl-leucyl-phenylalanine-induced monocyte polarization assay was used throughout this study because this monocyte function has been shown to be highly sensitive to TM protein p15E-related immunosuppression. We found that in addition to CKS-17 one CKS-17-derived hexapeptide, LDLLFL, reversibly inhibited monocyte polarization, with 50% inhibitory concentrations of 20 and 2 microM respectively. LDLLFL-mediated inhibition was sequence specific because the reverse peptide LFLLDL and scrambled peptides were not inhibitory. Hexapeptides corresponding to LDLLFL, but derived from various retroviruses other than murine leukemia virus, also inhibited monocyte polarization. Peptides most homologous to LDLLFL-LDILFL (feline leukemia virus) and LDLLFW (human T lymphotropic virus types I and II)--were the most potent inhibitors. Peptides homologous to primate and human endogenous proviruses were not suppressive. LDLLFL and some of its homologous also inhibited polarization of neutrophilic granulocytes. These findings lend further support to the view that conserved retroviral TM protein-related peptides can play an important role in suppression of inflammatory cell function as encountered in retrovirus-associated immunosuppression.

Adult↗
PubMed1992

Treatment with tumour infiltrating lymphocytes and interleukin-2 in patients with metastatic melanoma: a pilot study.

Tumour infiltrating lymphocytes (TIL) were isolated and expanded from biopsy samples of 4 patients with metastatic melanoma. The patients were treated with autologous expanded TIL and continuous or bolus infusion of Interleukin 2 (IL-2) at a dose of 18 x 10(6) International Units/m2/day for 5 days starting 36-48 hours after administration of cyclophosphamide at a dose of 1 g/m2. The number of TIL infused ranged from 10(10) to 5.56 x 10(10) cells. Two patients had stable disease (SD) lasting for 2 1/2 and 4 months respectively and they died 24 and 13 months after therapy. One patient died during therapy due to a pseudomonas septicaemia and another patient developed progressive disease (PD). He died 3 months after the start of therapy. The side effects were substantial but most of them were reversible upon cessation of the treatment. The majority of the expanded TIL of all patients were of the CD8+ phenotype. Cutaneous metastases from two patients, removed after treatment with IL-2 and TIL, showed moderate lymphocytic infiltration also mainly of CD8+ T cells. The treatment with IL-2 and TIL is feasible, but further investigations should continue in an attempt to improve the efficacy of the therapy, to reduce toxicity and to diminish the costs and labour of the culture methods.

Cell Division↗
PubMed1992

Persistent immune tolerance to nickel and chromium by oral administration prior to cutaneous sensitization.

Oral administration of allergens, foreign proteins, or cell-bound antigens may induce systemic suppression of subsequent humoral and cell-mediated immune responses ("oral tolerance"). The induction of specific immune tolerance provides a potential strategy for treatment of T-cell-dependent immune diseases. Therefore, in depth studies into preconditions for optimal and persistent tolerance induction are mandatory. Here we report on such studies in a guinea pig model using the non-cross-reactive contact allergens nickel and chromium. Feeding per os of nickel sulfate or potassium dichromate did not trigger systemic TDTH-effector functions. Instead, short feeding periods led to a dose-dependent, and metal-specific, suppression of subsequently induced allergic contact hypersensitivity. Administration of the allergens onto the oral mucosa was most effective in the induction of immune tolerance. When first sensitizing attempts were delayed until 1 year after feeding, the degree of unresponsiveness was reduced. In contrast, with cutaneous contacts starting shortly after the feeding period, tolerance was fully stable and undiminished for at least 2 years. Thus, in orally treated guinea pigs cutaneous contacts provide boosting tolerogenic signals, supporting the view that oral tolerance does not result from clonal deletion but from active antigen-specific immunosuppression. Indeed, unresponsiveness to cutaneous immunization could be transferred by lymphoid cells from fed guinea pigs in a metal-specific way.

Administration, Oral↗
PubMed1992

Distribution of retroviral p15E-related proteins in neoplastic and non-neoplastic human tissues, and their role in the regulation of the immune response.

In patients with head and neck carcinomas and in patients with chronic purulent upper airway infections, low molecular weight retroviral p15E-like factors are found. These factors are responsible for partial defects in the cellular immune response. We studied the distribution of these p15E-related proteins in neoplastic, inflamed and normal human tissues and related these findings with the presence of p15E-like factors in patients' sera. Demonstration of p15E-like proteins in sera of patients with upper airway infections and of patients with head and neck carcinomas correlated exclusively with the presence of p15E in normal and pathologic epithelium of the upper respiratory tract. p15E was not demonstrated in epithelia of other localizations. Our results suggest that chronic stimulation or neoplastic transformation of the epithelia of the upper respiratory tract stimulates the production of p15E-like proteins leading to their reported immunosuppressive actions.

Adolescent↗
PubMed1992

Development of a concomitant nickel and chromium sensitization model in the guinea pig.

Although nickel allergy is the most frequent contact hypersensitivity in man, reports on successful nickel sensitization in experimental animals are scarce. Chromium hypersensitivity, on the other hand, is readily induced in guinea pigs. In this study we set out to obtain reproducible nickel sensitization in guinea pigs, in order to establish an animal model for immunospecific tolerance and desensitization studies in which two non-cross-reacting metal allergens, chromium and nickel, could be studied simultaneously. Strong and reproducible sensitization to nickel was achieved by injecting low amounts of Freund's complete adjuvant and nickel sulfate in a split-adjuvant procedure. Strong erythematous reactions were observed as early as 14 days after sensitization and could be elicited both by intradermal and open epicutaneous challenges. Optimal evaluation was with nickel sulfate administered epicutaneously in 40% dimethyl sulfoxide to enhance skin penetration. Hypersensitivity could be transferred with lymphocytes and not with serum. Sensitization procedures for nickel and chromium then could successfully be combined in a double sensitization procedure. With four different guinea pig strains no genetic restriction was observed for the induction of nickel or chromium sensitivity. However, for both metals a clear sex and age dependence was observed: female guinea pigs reached a higher degree of sensitization than males, whereas sensitization in young animals was relatively weak.

Administration, Cutaneous↗
PubMed1992

Multidrug resistance gene (P-glycoprotein) expression in the human fetus.

P-glycoprotein, a transmembrane protein associated with multidrug resistance in cancer cells, is also expressed in normal tissues. To get more insight into the physiologic role of mdr1/P-glycoprotein, we investigated its expression in human fetal tissues after 7 to 38 weeks of gestation by an immunohistochemical technique, using three different monoclonal antibodies, and by a sensitive RNAse protection assay. Expression of mdr1-mRNA could already be demonstrated in the embryonal phase of human development, after 7 weeks of gestation. Comparing the adult with the fetal tissue distribution, differences were found in specific organs, such as adrenal, intestine, respiratory epithelium, and brain capillaries. In the fetal zone cells of the fetal adrenal cortex no staining was observed by immunohistochemistry, whereas the definitive zone showed increasing expression throughout gestation. Prenatal intestine did not show staining of the epithelium, although definite mdr1-mRNA expression was observed in late specimens. Interestingly, respiratory epithelium of main bronchi and pharynx, not expressing P-gp in adults, did stain positive. Expression of P-gp in brain capillaries was not observed before the third trimester of pregnancy, whereas in kidney and liver, mdr1-mRNA expression and staining for P-glycoprotein were detected in early fetal life (11 to 14 weeks). These findings suggest a pivotal role of P-glycoprotein in physiology of various organs already in early phases of human development and may help to identify its physiologic substrates.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Subpopulations of guinea-pig T lymphocytes defined by isoforms of the leucocyte common antigen.

This report presents the characterization of three mouse monoclonal antibodies (mAb) reactive with the guinea-pig leucocyte common antigen (LCA); CD45 in the human nomenclature. One, IH-1, reacted with LCA on all leucocytes. The other two were more restricted: IH-2 recognized only the 220,000, 210,000 and 195,000 MW isoforms, and IH-4 the 220,000, 210,000 MW isoforms. Both IH-2 and IH-4 reacted with all B cells and all Kurloff cells [the putative guinea-pig natural killer (NK) cell]. IH-2, but not IH-4, reacted with monocytes and macrophages. Neither reacted with neutrophils. Most thymocytes expressed low levels of the IH-2 and IH-4 epitopes, with those expressing high levels located predominantly within the medulla. Most (90%) CD4+ T cells from newborn guinea-pigs expressed high levels of the IH-2 and IH-4 epitopes; this percentage decreased with age to 70% in 2-year-old animals. We have demonstrated that CD4+ T cells which express low levels of the IH-2 epitope also express low levels of the IH-4 epitope. CD8+ T cells can be divided into two subsets by IH-4 but not IH-2. The reactivities of IH-2 and IH-4 are remarkably similar to those of human anti-CD45RB and anti-CD45RA antibodies respectively. Analogies with man and other species suggest important functional differences for subpopulations of guinea-pig T lymphocytes defined by anti-CD45R antibodies.

Aging↗
PubMed1991

The VLA-4/VCAM-1 pathway is involved in lymphocyte adhesion to endothelium in rheumatoid synovium.

Lymphocyte migration to inflammatory sites is an essential factor in the pathogenesis of chronic inflammation. An ensemble of adhesion receptors mediating lymphocyte-endothelial cell recognition and binding are thought to play a crucial role in this process. In the present study, we have explored the molecular basis of lymphocyte adhesion to endothelium in the synovial membrane of patients with rheumatoid arthritis. We established that the very late antigen-4 [VLA-4 (CD49d)] and the vascular cell adhesion molecule-1 (VCAM-1) are important mediators of binding to synovial endothelium of resting and, to a greater extent, of activated T lymphocytes, whereas the leukocyte-function associated antigen-1 [LFA-1 (CD11a/18)]/intercellular adhesion molecule-1 [ICAM-1 (CD54)] pathway is less important in this interaction. In contrast to its prominent role in lymphocyte interaction with endothelium in rheumatoid synovium, the VLA-4/VCAM-1 pathway does not significantly contribute to lymphocyte adhesion to peripheral lymph node high endothelial venule. Thus, the VLA-4/VCAM-1 pathway may be of primary importance in mediating lymphocyte adhesion to inflamed endothelium and in lymphocyte homing to rheumatoid synovium.

Antibodies, Monoclonal↗
PubMed1991

Altered expression of P-glycoprotein and cellular adhesion molecules on human multi-drug-resistant tumor cells does not affect their susceptibility to NK- and LAK-mediated cytotoxicity.

Drug resistance has been associated with resistance to NK- and LAK-cell-mediated cytotoxicity. We evaluated this issue in human cell lines, using multiple myeloma cells (8226) and 2 multi-drug-resistant (MDR) sublines selected using doxorubicin (8226/Dox40) and mitoxantrone (8226/MR40). In parallel, we studied the human breast carcinoma cell line series MCF7, MCF7/D40 and MCF7/Mitox. Unlike the sensitive parental cell lines, all 4 sublines display MDR-patterns of resistance, with the P-glycoprotein pump (P-170) detected only in the doxorubicin-selected sublines. Flow cytometric and immunocytochemical analyses showed expression of cellular adhesion molecules ICAM-I and LFA-3, and MHC-Class-I (MCF7/D40 only), to be decreased in the doxorubicin-selected MDR-sublines, whereas expression of CD56 (Leu 19) was strongly up-regulated in 8226/Dox40. Lysis of P-170-positive MDR tumor cells by NK or LAK cells was, however, unaffected by these alterations, suggesting redundancy in effector:target-cell adhesion pathways. Mitoxantrone-selected tumor cells did not display P-170, nor did they show altered expression of cellular adhesion molecules. Their susceptibility to NK or LAK cytolysis was also unimpaired as compared to the parental cell lines. Clinically, these results imply that immunotherapeutic modalities aiming at increased natural killer functions deserve full consideration even in patients who have become refractory to further cytostatic drug treatment.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Tumor regression and induction of anti-tumor immunity by local chemotherapy of guinea-pigs bearing a line-10 hepatocarcinoma.

Local administration of a low dosage of the active cyclophosphamide derivative 4-hydroperoxy-cyclophosphamide (4-HPCY) at the site of antigenic stimulation strongly enhances T-cell-mediated immune responses in both mice and guinea-pigs. Such immunopotentiation is related to functional elimination of suppressor cells from the draining lymph nodes. In the present study we examined the potential immunotherapeutic effects of local cytostatic drug administration in strain-2 guinea-pigs bearing a line-10 hepatocarcinoma. This tumor, when injected intradermally (10(6) cells) metastasizes within 7 days into the draining lymph node and untreated animals die within 60-80 days from metastatic growth. In sensitization experiments, using irradiated line-10 tumor cells, potentiation of delayed-type hypersensitivity reactivity was observed with local administration of low dosages of 4-HPCY. Intralesional treatment with increasing dosages of 4-HPCY, when started 7 days after tumor-cell inoculation and continued for 3 weeks, resulted in a dose-dependent regression of the primary tumor. Cure rates of up to 75% were achieved. All cured animals showed strong delayed-type hypersensitivity reactivity towards line-10 cells and were resistant to a rechallenge with 10(6) line-10 tumor cells. When treatment was started at a very late stage of the disease (day 14) only a small number of animals were cured. However, when local chemotherapy was preceded by one (non-curative) systemic dose of cyclophosphamide, a 57% cure rate was obtained. Again, all cured animals showed strong delayed-type hypersensitivity reactivity and protective immunity to line-10 tumor cells. Tumor immunity was transferable to naive recipients with immune spleen cells and was T-cell-dependent. Other cytostatic drugs, selected for local immunopotentiating capacity, notably etoposide (VP16) and cis-platinum (cis-Pt) were similarly effective in the local chemotherapy protocol.

Adjuvants, Immunologic↗
PubMed1991

T cell proliferation induced by monoclonal antibodies to a phosphatidylinositol-linked differentiation antigen of guinea pig lymphocytes.

Monoclonal antibodies (mAb) to differentiation antigens frequently influence the in vitro function of antigen-bearing cells. We characterized a 32-36-kDa membrane protein expressed on guinea pig lymphocytes and Langerhans cells. A series of independently derived mAb to this protein, now called guinea pig T cell activation antigen (gpTAA), induced strong proliferation of T cells in vitro. Cross-linking of the mAb by a secondary antibody (rabbit anti-mouse Ig) and costimulation with phorbol 12-myristate 13-acetate were required for activation. Treatment of the cells with phosphatidylinositol-specific phospholipase C greatly reduced the amount of antigen expressed on the cell surface as measured by flow cytometry analysis. This finding indicates that the antigen is anchored to the cell membrane via phosphatidylinositol linkage as shown similarly for other membrane proteins with T cell activating properties, e.g. Thy-1 and Ly-6. The guinea pig protein differs, however, in its molecular weight and tissue distribution from similar proteins identified in the mouse or in the rat system. Unlike Thy-1, gpTAA is also expressed on B Lymphocytes and Langerhans cells. Considering the previously described involvement in cellular adhesion, and the functional characteristics reported here, gpTAA might represent a new species of differentiation antigen with T cell-activating capacity.

Animals↗
PubMed1991

Tumour rejection after adoptive transfer of line-10-immune spleen cells is mediated by two T cell subpopulations.

The growth of line-10 tumours in naive guinea pigs is prevented by adoptive transfer of spleen cells that are hyperimmune to this hepatocellular carcinoma. To study the T cell subpopulations responsible for the adoptive transfer of immunity, various cell populations were removed from immune spleen cells using monoclonal antibodies (mAbs) and magnetic microspheres. Spleen cell subpopulations were identified by mAb after flow cytometry and rosette formation with the magnetic microspheres. mAb CT5 was confirmed to be a pan T cell marker, while the CT6 (anti-T-suppressor/cytotoxic) and CT7 (anti-T-cell) markers were present on two different T cell subpopulations. So our results show that CT7 mAb cannot be used as a pan T cell marker as was published previously. Moreover, the mAb H155 (anti-T-helper/inducer) reacted with the same T cell subpopulation recognized by CT7. So we designated this H155/CT7-positive subpopulation as T helper/inducer cells. Removal of the CT6-, CT7-, or the H155-positive T cells from the immune spleen cells resulted in loss of the in vitro proliferative response to line-10 tumour protein and tuberculin purified protein derivative (PPD). The H155/CT7 (anti-T-helper/inducer)-positive spleen cells did not express MHC class II antigens as determined by mAb 25E3. In most experiments, elimination of MHC-class-II-positive cells did not change the in vitro proliferative response to line-10 protein, whereas the response to tuberculin PPD was completely abrogated. Immune spleen cells after depletion of CT6-, CT7- or H155-positive cells, failed to transfer immunity. However, after depletion of MHC-class-II-antigen-positive cells the line-10 immunity was still present, whereas the immune response to tuberculin PPD was lost. In conclusion, our data indicate that immunity to the line-10 tumour is the result of a cooperation between at least two different T cell subpopulations, the T helper/inducer (CT7/H155) cells and the T suppressor/cytotoxic cells (CT6). If this is a common feature, then the therapeutic approach of in vitro expanded TIL cells should take into consideration the requirement of two T cell subsets.

Animals↗
PubMed1991

Major histocompatibility complex class II antigen expression on leucocyte subpopulations in the draining lymph node and tumour in the early phase of bacillus-Calmette-Guérin-induced tumour regression.

We investigated the cellular composition and the major histocompatibility complex (MHC) class II antigen expression in the draining lymph node and the tumour during potentiation of the immune response by intralesional bacillus Calmette-Guérin (BCG) administration in the line 10 hepatocellular carcinoma in the strain 2 guinea-pig. Five days after its injection BCG induced a ninefold increase in the number of draining lymph node cells and an increased MHC class II expression. This increased MHC class II expression was mostly due to the selective increase of B cells in the lymph nodes, and to a lesser extent to the increase of T cells expressing MHC class II antigens. Taking into account this nine-fold increase, intralesional treatment of BCG increased considerably the number of T helper/inducer (anti-CT7) and T suppressor/cytotoxic (anti-CT6) lymph node cells expressing MHC class II antigen. The percentage of tumour-infiltrating T cells expressing MHC class II antigen in the tumour was higher than the percentage of T cells in the regional draining lymph node of non-treated guinea-pigs, indicating the presence of activated T cells in the tumour. After treatment with BCG no further increase in MHC class II expression was measured in the tumour, nor was any phenotypical change of the tumour-infiltrating T cells found. In conclusion, with the use of two-colour flow cytofluorometry we have shown that the potentiation of the already existing immune response to line 10 is accompanied by a considerable increase in T helper/inducer, T suppressor/cytotoxic cells and MHC class II antigen in the regional lymph node. Whether this is essential for the potentiation of the immune response causing tumour regression and long-lasting immunity is a subject for further study.

Animals↗
PubMed1991

Treatment of leptomeningeal carcinomatosis with continuous intraventricular infusion of recombinant interleukin-2.

A 42-year-old man developed leptomeningeal carcinomatosis 6 years after treatment of a malignant melanoma. He was treated with two courses of recombinant interleukin-2, administered as a continuous intraventricular infusion (6 X 10E5 U/24 h) during 5 days. During the first day of the first course he also received 5 X 10E9 lymphokine-activated killer cells intraventricularly. This gave rise to a severe elevation of intracranial pressure, with headaches and meningismus. During the second course no LAK cells were administered. This course was tolerated much better. The neurological status did not change during the treatment. Recombinant interleukin-2 levels were maintained at about 300 U/mL during both courses.

Adult↗
PubMed1991

Early multidrug resistance, defined by changes in intracellular doxorubicin distribution, independent of P-glycoprotein.

Resistance to multiple antitumour drugs, mostly antibiotics or alkaloids, has been associated with a cellular plasma membrane P-glycoprotein (Pgp), causing energy-dependent transport of drugs out of cells. However, in many common chemotherapy resistant human cancers there is no overexpression of Pgp, which could explain drug resistance. In order to characterise early steps in multidrug resistance we have derived a series of P-glycoprotein-positive (Pgp/+) and P-glycoprotein-negative (Pgp/-) multidrug resistant cell lines, from a human non-small cell lung cancer cell line, SW-1573, by stepwise selection with increasing concentrations of doxorubicin. These cells were exposed to doxorubicin and its fluorescence in nucleus (N) and cytoplasm (C) was quantified with laserscan microscopy and image analysis. The fluorescence N/C ratio in parent cells was 3.8 and decreased both in Pgp/+ and Pgp/- cells with increasing selection pressure to 1.2-2.6 for cells with a resistance factor of 7-17. N/C ratios could be restored partly with verapamil only in Pgp/+ cells. N/C ratio measurements may define a general Pgp-independent type of defense of mammalian cells against certain anticancer agents which may precede Pgp expression in early doxorubicin resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗