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Biomedical subjects

J Sinkovics

Publications and source records attributed to J Sinkovics.

9 recordsLinked to original sources

[Interleukin-6].

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AIDS-Related Opportunistic Infections

Human cancer vaccines.

Immune T cells recognize peptide antigens presented to them within self-MHC molecules. Thus auto-tumor reactive lymphocyte populations can be generated. Antigenic expression can be modified and intensified and reactive lymphocyte populations can be expanded. Active immunization of the tumor-bearing human host can induce immune reactions of tumor rejection strength. Frequently, micrometastases can be eliminated and occasionally partial or complete remissions of gross metastases can be induced.

BCG Vaccine

Apoptosis by genetic engineering.

Apoptotic cell death is physiological. Malignant cells often escape programmed cell death. Many genes that promote (p53) or antagonize (bcl-2, fes) apoptosis have been recognized. Apoptosis promoter genes can be activated by growth factor or hormone withdrawal in growth factor- or hormone-dependent tumor cells. Malignant cells acquiring apoptosis-resistance, still can be killed by cytotoxic lymphocytes releasing lymphotoxins. This phenomenon gives further support to the therapeutic use of activated and expanded lymphocyte populations and/or apoptosis-inducing cytokines. Chemotherapeutic agents (esp. topoisomerase inhibitors) frequently kill tumor cells by activating programmed cell death (PCD). Biologicals and chemotherapeutics may synergize in evoking apoptosis. We propose the cloning of apoptotic genes and their transfer by transfection in vivo into tumor cells. While transfection of genes into tumor cells in vitro is widely practiced, the lack of proper technology for transfection in vivo and the unknown aspects of apoptotic cell death are recognized.

Animals

New developments in the virus therapy of cancer: a historical review.

Since the 1920s, viruses had been used for oncolysis. Natural human viral infections can rarely induce remissions of leukemias or lymphomas. Inoculation of tumor-bearing patients with live viruses very seldom resulted in durable complete remissions. Genetically engineered or tumor-adapted virus strains may perform better. Virally modified tumor cell membrane vaccines can induce in the host rejection strength antitumor immunity. Modern technology and much more work is needed before the optimal procedures for viral oncolysis or active antitumor immunization with virally modified tumor cell vaccines are learned and can be implemented in the clinical practice. Laboratory monitoring of the host's immunological reactions accompanying failure and success of tumor rejection is essential for the recognition and duplication of the successful and for the avoidance of the unsuccessful interventions.

Genetic Engineering

Cytotoxic human lymphocytes: from in vitro testing (1970s) to immunotherapy (1990s).

The senior author was the recipient of a contract (1-CP3-3292) from the National Cancer Institute, USA (NCI) in the early 1970s. The aim of NCI's targeted research program was the establishment of a tumour-specific human lymphocyte-mediated cytotoxicity assay. Neither lymphocyte growth factors nor monoclonal antibodies for lymphocyte typing were available. Tumour-specific populations of lymphocytes could not be maintained but their presence in ficoll-hypaque preparations of blood buffy coats or in primary cultures of tumours was clearly recognized. Another indiscriminately cytotoxic population of lymphocytes had usually overridden the tumour-specific population. In contradistinction to the ruling doctrine of the era, indiscriminately cytotoxic lymphocytes were readily found in the blood of tumour-bearing patients and healthy individuals (the senior author's lymphocytes were shown to practice indiscriminate cytotoxicity in 1971, an observation first interpreted as "immune surveillance at work" in an individual daily exposed to patients with metastatic cancers). Instead of converting the subject matter of the contract from a tumour-specific to a non-specific cytotoxicity assay, the NCI prematurely "phased it out" (but continued the project as intramural research). Nevertheless, many functions of cytotoxic lymphocytes that had become by now well established were foreshadowed during the early 1970s with the limited support of that NCI contract and funds from other sources. Here we recount those early observations; present the outlines of adoptive immunotherapy with various autologous lymphocyte populations and in a separate report in this volume give a technical description how these lymphocyte populations are prepared in the laboratory for therapeutic reinfusions into the patient.

Animals