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Biomedical subjects

W H Fridman

Publications and source records attributed to W H Fridman.

At least 163 records · Page 9Linked to original sources
PubMed1992

Current status of interleukin-2 therapy in cancer.

In vitro studies and animal experiments showed the existence of a physiological immune response against tumors. Interleukin-2 was the first immunological agent which demonstrated an anti-tumor effect by activating immune effectors. In vitro IL2 may generate Lymphokine Activated Killer (LAK) cells from peripheral blood lymphocytes or Tumor Infiltrating Lymphocytes (TIL) expanded from tumor. In melanoma and renal cell carcinoma, IL2 alone or associated with LAK cells or TIL, mediated clinical responses. However, their clinical efficacy was associated with some toxicity related to a capillary leak syndrome. This implies an improvement in the selection of patients and in the understanding of IL2 action. Future directions in immunotherapy included combination IL2 with other cytokines or monoclonal antibodies or chemotherapy. Lymphokine gene therapy is designed to introduce IL2 or other cytokine genes into tumor infiltrating lymphocytes or directly into tumors to reduce systemic toxicity and to achieve high local cytokine concentration. Animal models and the first human trials make this approach promising.

Animals↗
PubMed1992

Soluble Fc gamma R (sFc gamma R): detection in biological fluids and production of a murine recombinant sFc gamma R biologically active in vitro and in vivo.

Soluble forms of receptors for the Fc portion of IgG (sFc gamma R) were detected in biological fluids from mice and humans. In mouse bearing tumors, circulating amounts of sFc gamma R increased concurrently with tumor growth. Tumors secreting IgG2a, IgG2b or IgG3 led to a 5- to 10-fold increase in serum sFc gamma R levels whereas tumors secreting IgG1, IgGA or other types of tumors (non Ig B cell tumors, T cell lymphoma and a melanoma) increased 2- to 3-fold the levels of circulating sFc gamma R. In the human, sFc gamma R were also detected in whole unstimulated saliva. Levels of sFc gamma RII and of sFc gamma RIII were variable and did not seem to depend on the dental status of the individuals. Finally, a murine recombinant sFc gamma R (rsFc gamma R) composed of the two extracellular domains of Fc gamma RII was produced by culture of transfected L cells in bioreactors. The purified rsFc gamma R was found to inhibit antibody production in vitro in anti-SRBC responses and by cultures of small B cells stimulated by anti-IgM antibodies in the presence of IL-4 and IL-5. Moreover, the i.p. injection of this material into adult mice immunized with SRBC led to a decrease of IgG antibody production by splenocytes, as measured by a hemolytic plaque assay, and in serum, as measured by antigen-specific ELISA.

Animals↗
PubMed1992

Two distinct regions of the mouse beta Fc gamma R gene control its transcription.

The low-affinity receptors for the Fc portion of IgG (Fc gamma RII and Fc gamma RIII) are born by most of the immunocompetent cells and mediate a wide spectrum of biological activities. Macrophages, mast cells and lymphocytes express the type II Fc gamma R whereas the type III Fc gamma R is expressed on macrophages, mast cells and NK cells. In mice, the beta Fc gamma R gene codes for Fc gamma RII and the alpha Fc gamma R gene codes for the ligand-binding Fc gamma RIII alpha-chain. We have previously demonstrated that the methylation of the 5' region of these genes control their expression. In the present paper, we investigate the role of two unmethylated regions of the beta gene, the promoter and the third intron, in the control of its transcription. We show, by using two cell lines representative of B and mast cells, that different promoter fragments determine, in these two cell types, the transcription of the beta Fc gamma R gene. The third intron of the beta Fc gamma R gene contains sequences, which, introduced upstream to homologous or heterologous promoter, inhibit the transcriptional activity of these promoter. Thus, in B cells and in mast cells, the transcription of the beta Fc gamma R gene is controlled by two distinct regions of the gene.

Animals↗
PubMed1992

Phenotypic properties of 3T3 cells transformed in vitro with polyoma virus and passaged once in syngeneic animals.

Cloned BALB/c 3T3 cells transformed in vitro with polyoma virus (PyV) acquired a higher tumorigenicity phenotype after a single in vivo passage. Some of the in vivo passaged cells (CTC cells) exhibited also a higher metastatic phenotype than cells from the same clones that were maintained only in culture (C cells). A phenotypic comparison between CTC and C cells was performed. It was found that most CTC lines exhibited a higher binding to laminin compared to their clonal C cell ancestors. Some CTC cells were less sensitive to the cytotoxic effects of TNF-alpha than the corresponding C cells. CTC cells originating from tumors which appeared after a long latency period (late tumors) tended to express Fc gamma RII while CTC cells originating from tumors which appeared after a short latency period (early tumors) as well as the corresponding C cells tended not to express Fc gamma RII. The expression of a membrane epitope recognized by a monoclonal antibody expressing specificity towards PyV transformed cells, was down-regulated on late tumor cells compared to early tumor cells. Transfection of cloned PyV-transformed BALB/c 3T3 cells with the beta 1Fc gamma RII gene augmented the tumorigenicity and metastatic phenotype of the transfectants compared to control transfectants.

3T3 Cells↗
PubMed1992

Possibilities of interference with the immune system of tumor bearers by non-lymphoid Fc gamma RII expressing tumor cells.

The ectopic expression of Fc gamma RII by PyV transformed 3T3 cells derived from tumors of long latency has been established. It was suggested that this expression is one of several changes conferring upon the cells an increased capacity for survival. We found that in one case cells expressing a very high level of Fc gamma RII had also a very high metastatic phenotype as compared to FcR negative cells. Direct evidence that Fc gamma RIIbl functions as a progression factor was provided by transfection experiments. The transfected gene conferred an increased malignancy and invasive phenotype upon PyV or c-Ha-ras transformed cells. In the present study we tested the possibility that Fc gamma RII expressing tumor cells could interfere with the immune system. The following subjects were investigated: 1) The ability of Fc gamma R on the tumor cells to bind the ligand and/or release IBF. 2) The effect of a local accumulation of ligand and/or IBF (assumed to take place in situ in the tumor) on Fc gamma RII expressing T cells. It was found that both tumor-derived receptor positive and beta l transfected PyV transformed cells were capable of binding aggregated mouse IgG. The binding of bivalent ligand was followed by an increase in membrane Fc gamma RII expression. Also both types of cells were capable of releasing IBF. We then tested the possibility that a local accumulation of IgG within the tumor could effect Fc gamma R expressing T cells. It was found that aggregated mouse IgG (as well as IgGl) could stimulate the proliferation of the T cell hybridoma (T2D4) and other Fc gamma RII expressing T cells. We also found that the expression of beta Fc gamma RII specific mRNA peaked at the logarithmic phase of T2D4 cultures, in parallel with their maximal potential to release IBF. Several pathways for interference with the immune system are suggested.

3T3 Cells↗
PubMed1992

Release of soluble Fc gamma RII/CD32 molecules by human Langerhans cells: a subtle balance between shedding and secretion?

Freshly isolated human Langerhans cells (LC) express two forms of Fc gamma RII: a membrane-associated form detected by monoclonal antibody (MoAb) anti-CD32, which recognize an extracytoplasmic epitope of the molecule, and a soluble secreted form, whose existence is suggested by reverse transcriptase-polymerase chain reaction (RT-PCR) experiments. Indeed, RT-PCR performed on total LC RNA reveals the presence of two Fc gamma RIIA mRNA, one encoding the FC gamma RIIA with a transmembrane region (membranous form) and the other without this region (soluble form). Densitometry studies performed on the two PCR products reveal that the ratio between the membranous form and the soluble secreted form is about 1.5. LC maintained in culture for 24-48 h lose the major part of their membrane Fc gamma RII expression (shown by flow cytometry) and release soluble Fc gamma RII molecules (revealed by dot-blot assay), but maintain the same ratio of the two Fc gamma RIIA mRNA. The disappearance of the membrane-associated Fc gamma RII may be explained either by modification of its recycling pathway or by proteolytic cleavage of the receptor at the cell surface. Thus, soluble Fc gamma RII molecules generated during LC culture may result from proteolytic cleavage of the cell-surface receptor and/or secretion of a soluble form derived from the translation of an alternate spliced mRNA. Interestingly, addition of TNF-alpha (10 ng/ml) to the culture medium i) maintains the expression of the membranous form, which can be detected on the LC surface at the same level as on freshly isolated LC, and ii) reverses the ratio (to 0.6) of the two Fc gamma RII mRNA, the mRNA encoding the soluble form becoming predominant. Thus, TNF-alpha seems to modify the expression of the Fc gamma RII at the mRNA level, favoring the secretion of soluble Fc gamma RII molecules, and changes the fate of the membranous Fc gamma RII.

Humans↗
PubMed1992

Increased levels of soluble low-affinity Fc gamma receptors (IgG-binding factors) in the sera of tumour-bearing mice.

Soluble forms of low affinity Fc gamma receptors (Fc gamma R), also called IgG-binding factors (IgG-BF), have been shown to play a regulatory role in immune responses. By using an immunodot assay with the anti-mouse Fc gamma R MoAb, 2.4G2, the levels of IgG-BF have been measured in the sera of mice bearing syngeneic tumours of lymphoid or non-lymphoid origin or in mice injected with high doses of murine IgG. These sera contained large amounts of IgG-BF as compared with controls. In the case of mice bearing IgG2a- or IgG2b-secreting hybridomas or lymphomas, serum IgG-BF increased progressively with tumour size and serum monoclonal IgG concentration, reaching 4-12 times the normal levels. A less than three-fold increase was found in mice bearing an IgG1-secreting hybridoma or tumours which do not secrete IgG (IgA-secreting hybridoma, non-immunoglobulin-secreting lymphoid tumours or melanoma) or in mice injected with 9 mg of monoclonal IgG2a. The enhancement of serum IgG-BF levels was independent of the expression of Fc gamma R by the tumour cells, suggesting that the majority of IgG-BF secreted in response to tumours was produced by the host rather than by the tumour. The increased production of IgG-BF may participate in the control of tumour growth and in the modulation of the host immune responses in tumour-bearing animals.

Animals↗
PubMed1992

IL-2 phase II trial in metastatic melanoma: analysis of clinical and immunological parameters.

Twenty-four patients with histologically proven metastatic malignant melanoma were included in a phase II trial of recombinant IL-2 (rIL-2, RU 49637). Twenty million international units (IU)/m2/day were given by continuous intravenous infusion on days 1 to 5, 15 to 18, and 29 to 31, and then monthly for 5 days until disease progression or major intolerance developed. All patients were evaluable for response and toxicity. Toxicity was consistent with one case of myocardial ischemia, 13 cases of grade III and IV hypotension, and 15 cases of proven sepsis. There were 8 objective responses: 4 of them were of short duration as they were observed on day 31 only. An activation of the immune system was detected in all patients. It was demonstrated by an increase in lymphocyte populations, especially in activated NK cells. A tendency for higher numbers of cytotoxic cells was found in patients with objective tumor responses. These results indicate a role for rIL-2 RU 49637 in treating patients with metastatic malignant melanoma. However, further trials are required to determine its optimal dosage and schedule of administration.

Adolescent↗
PubMed1992

[Demonstration of soluble IgG-Fc type II receptors (or s-Fc-gamma-II-R) in human whole saliva].

Twenty human salivary samples from two groups of patients (with or without dental caries) were tested for the presence of soluble forms of Fc gamma receptors type II (sFc gamma RII): sFc gamma RII were detected by immunoblotting using a radiolabelled monoclonal antibody directed against human Fc gamma RII. These soluble forms specifically interact with the Fc portion of IgG and are produced by cells of the immune system (macrophages, neutrophils, Langerhans cells). This study showed that sFc gamma RII are present in human unstimulated saliva. The statistical analysis indicated that the relative amounts of sFc gamma RII in human unstimulated saliva are variable depending on the patient. No apparent association was found between the sFc gamma RII and the oral status of the patients.

Adult↗
PubMed1992

[Treatment of metastatic malignant melanoma with interleukin-2].

Between April 1988 and December 1990, 37 patients with progressive histologically proven metastatic melanoma were treated with interleukin-2 according to three multicentric successive protocols. Eighteen males and 19 females entered the trial. Mean age was 44 years (range 20-66); none of the patients had severe visceral disease or brain metastasis. Superficial and visceral metastatic sites were equally distributed. Interleukin-2 was administered as a 3 to 5 day continuous intravenous infusion, at a dose varying from 16 to 24 million international units/m2/day, as previously described by West. The second course was given after a 9 to 16 day free interval and one to seven courses were administered (mean three courses). A total of 132 courses has been given to the 37 patients. All are evaluable for toxicity and efficacy. Toxicity was tolerable and not different from that presented in recent reports. Only four patients had to definitively stop therapy for toxicity, one of them for cardiotoxicity; a dose modification or a transient suspension of therapy occurred in 18% of treatment cycles. One hypothyroidism with anti-thyroglobulin and anti-microsome antibodies was observed. We observed eight major responses (21.6%), usually of short duration (2-6 months). Most responses occurred in superficial lesions. One patient remains in complete remission, as therapy is stopped for 40 months. Immunological parameters, although demonstrating induced immunostimulation, did not correlate with clinical outcome. With an overall response rate of 21.6%, we confirm the activity of interleukin-2 in melanoma, as previously reported by others.

Adult↗
PubMed1991

Evaluation of circulating tumor necrosis factor-alpha in patients with gynecological malignancies.

TNF-alpha levels in sera from patients with gynecological cancers were evaluated by ELISA and compared with those of patients with benign ovarian cysts or of anonymous healthy donors. Patients with cervical and endometrial carcinoma and with benign ovarian cysts showed levels of TNF-alpha similar to those of healthy donors. In contrast, significantly increased levels of TNF-alpha were found in patients with ovarian carcinoma, regardless of the stage of disease.

Biomarkers, Tumor↗
PubMed1991

In vivo acquisition of Fc gamma RII expression on polyoma virus-transformed cells derived from tumors of long latency.

BALB/c 3T3 cells transformed in vitro with polyoma virus were cloned and passaged once in syngeneic mice. Resulting tumors from each clone were explanted and recultured. Expression of receptor for Fc of IgG (Fc gamma RII) in the original in vitro maintained clones and in cells derived from tumors elicited by the respective cells was measured at the protein level as well as at the mRNA level. Clones were assayed in pairs. The ancestor in vitro maintained clones [designated cultured cells (C)] were compared with cells derived from the same clones after a single passage in vivo followed by explantation and reculturing [designated cultured-tumor-cultured cells (CTC)]. C cells of any of the tested clones did not express Fc gamma RII. On the other hand, certain CTC cells were positive. The Fc gamma RII-positive cells were derived from tumors appearing after a long precancer latency period (greater than 140 days). CTC cells derived from tumors that appeared after shorter latency periods (less than 80 days) were Fc gamma RII negative. These results were obtained both by using radioimmunoassay and monoclonal antibodies against mouse Fc gamma RII as well as by Northern blot analysis using the Fc gamma RII complementary DNA probe. The involvement of macrophages as the Fc gamma RII-expressing cells in CTC cells was excluded. Fc gamma RII expression was down-regulated in CTC cells as a function of time following their explantation into culture. Fc gamma RII expression could be up-regulated in these cells and induced on C cells by maintaining the cultured cells in the presence of normal mouse serum or recombinant interferon. We also tested the expression of Fc gamma RII on CTC cells following their inoculation into syngeneic mice for a second time (CTCx2 cells). The results showed a positive correlation between Fc gamma RII expression in the inoculated ancestor CTC cells and on the CTCx2 cell progeny.

Animals↗
PubMed1991

Structure of the mouse beta Fc gamma receptor II gene.

We have isolated and deduced the structure of the beta Fc gamma RII gene from the mouse. This gene spans approximately 18 kb of DNA; the structure and nucleotide sequence has been determined and potential regulatory sites identified. This gene is composed of 10 exons that give rise to the beta 1 and beta 2 Fc gamma RII cDNA. Four exons encode the 5' untranslated region and leader sequence, one exon for each Ig-binding domain and membrane-spanning region and three exons encoding the cytoplasmic tail and 3' untranslated region. Analysis of the gene structure indicated that the beta 1Fc gamma RII and beta 2Fc gamma RII arise by differential mRNA splicing when a single 141-bp exon (exon 8) is alternately spliced to give rise to these isoforms. Sequence analysis of 2 kbp upstream of the transcription start site indicated the presence of regulatory elements, including three binding sites for the transcription factor Sp1, and Ap-4 binding site, a tandem glucocorticoid response element, and an overlapping tandem repeat. Furthermore, as in the Thy-1 gene, no CAT or TATA consensus sequences were observed. In addition, sites of methylation that regulate expression of this gene were also located at the 5' end of the gene and within several introns. A large intron located between exons 4 and 5 also contained a series of purine/pyrimidine-rich regions and a potential enhancer sequence.

Amino Acid Sequence↗
PubMed1991

Soluble Fc gamma receptors II (Fc gamma RII) are generated by cleavage of membrane Fc gamma RII.

This study describes the production of soluble Fc gamma RII by a cell line, D1B1, obtained by transfection of mouse L cells with a murine beta 1 Fc gamma RII cDNA. Upon incubation at 37 degrees C, radioiodinated D1B1 cells release a 39-kDa soluble Fc gamma RII, reacting with the rat anti-mouse Fc gamma RII monoclonal antibody 2.4G2, and binding to mouse IgG2a, IgG2b and IgG1 but not IgG3. In contrast to the transmembrane 50- to 70-kDa receptor, this soluble Fc gamma RII does not react with antibodies directed against a peptide corresponding to the 15 carboxy-terminal intracytoplasmic amino acids of beta Fc gamma RIII. N-Glycosidase F treatment generates a 18-kDa polypeptide. A 32- to 40-kDa soluble Fc gamma RII, which resolves into 18.5- and 20-kDa polypeptides after deglycosylation, was also isolated from the culture medium of unlabeled D1B1 cells. Therefore, this study indicates that soluble Fc gamma RII corresponding to the two extracellular domains of Fc gamma RII are generated by cleavage of membrane Fc gamma RII. Proteolysis occurs most probably at the vicinity of the transmembrane region of the receptor, around amino acids 165 to 180.

Animals↗