ABSTRACT
The production of interleukin-2 (IL-2) by mitogen-stimulated human peripheral blood leukocytes (PBL) was significantly enhanced by a short pretreatment of PBL with direct current (DC) at low intensities. Exposure of PBL to DC of 1 mA for more than 10 min resulted in inhibition of IL-2 production which correlated with decreased proliferation capacity of the treated cells. DC had similar enhancing and inhibitory effects on IL-2 production by the mitogen-stimulated human leukemia T cell line MOLT-13. However, DC itself did not stimulate IL-2 production in PBL or in MOLT-13 cells. In two additional T cell lines tested, MOLT-16 and H-9, DC did not enhance mitogen-stimulated IL-2 production, but suppressed it when applied at 1 mA for more than 10 min. Both the mitogen-stimulated and the interleukin-1 (IL-1)-enhanced IL-2 production were completely inhibited by 1 mA of DC applied for 20 min. The observed effects of DC were due to a direct action of DC on the cells and not to possible effects of the secondary by-products of electrolysis. These results show that pretreatment of cells with DC can enhance or suppress IL-2 production depending on the intensity of DC and the type of IL-2 producing cell clones.
Subject(s)
Electricity , Interleukin-2/biosynthesis , T-Lymphocytes/immunology , Humans , Lymphocyte Activation/immunology , Tumor Cells, CulturedABSTRACT
The effect of immobilization stress applied daily for 2 h on the development of MF-RSV tumor graft in mice and on survival of the hosts was studied. While a single acute stress applied to mice simultaneously with a transfer of MF-RSV cells stimulated antitumor defense, chronic stress applied both before and/or after tumor cell implantation accelerated the death of recipients. The shortest survival time was found in mice which were stressed for 3 weeks before implantation and on, until their death. Heat shock applied to MF-RSV tumor cells before implantation significantly reduced their growth ability in the hosts.
Subject(s)
Neoplasms, Experimental/pathology , Stress, Physiological/physiopathology , Animals , Cell Division/physiology , Cell Survival/physiology , Hot Temperature , Immobilization , Male , Mice , Mice, Inbred BALB C , Neoplasm Transplantation , Shock/physiopathology , Stress, Physiological/etiology , Tumor Cells, CulturedABSTRACT
The non-specific factor NSF17 produced by mouse newborn splenocytes fused with BW 5147 thymoma cells was tested in vivo for its immunosuppressive activity. NSF17 administered i.p. in a single dose into adult mice significantly decreased the PHA-induced proliferative response of lymphocytes, regional graft-versus-host reaction, and delayed-type hypersensitivity.
Subject(s)
Immunity, Cellular , Spleen/immunology , Suppressor Factors, Immunologic/physiology , Animals , Animals, Newborn , Graft vs Host Reaction/immunology , Hybridomas , Hypersensitivity, Delayed/immunology , In Vitro Techniques , Mice , Mice, Inbred CBA , Rats , Rats, Wistar , Thymoma/pathologyABSTRACT
The presence of very high numbers of type C and type A retroviral particles was repeatedly confirmed not only in myeloma cells NSI, Ag 8 and in thymoma cells BW5147, EL 4 but also in B and T cell hybridomas constructed from the myeloma and thymoma cells used. Retroviral particles were demonstrated by current electron-microscopic and physicochemical methods. Biological tests for the induction of possible malignant or any pathological changes in the artificially infected sensitive cells during long-term cultivations in vitro or in vivo gave negative results. Nevertheless, on account of the hitherto unknown action of retroviruses one can suppose that monoclonal products from B and T cell hybridomas, particularly when used for practical purposes, should be purified because of their infectious nature.
Subject(s)
Hybridomas/microbiology , Retroviridae/isolation & purification , Animals , Cell Transformation, Neoplastic , Hybridomas/ultrastructure , Mice , Microscopy, Electron , Retroviridae/ultrastructureABSTRACT
A continuous macrophage hybrid population, designated MBW-1, was produced by the fusion of peritoneal macrophages from a normal AKR mouse with thymoma cells BW5147. The hybrid cells are resistant to HA selection medium. In their nearly triploid chromosome complement they carry metacentric chromosomes typical of BW5147 cells and express the typical macrophage-like characteristics (morphology of macrophages, adherence properties, phagocytosis, expression of macrophage-specific antigen and receptor for the C3b component of complement). However, they do not express Fc receptors and the receptor for SBA lectin. An interesting property is the high resistance to the toxic action of silica particles. Thanks to the unique properties, which were not observed in other, hitherto described macrophage-like cell lines, the MBW-1 cell population provides a useful material for study of macrophage functions.
Subject(s)
Hybridomas/immunology , Macrophages/immunology , Animals , Cell Line , Macrophages/drug effects , Mice , Receptors, Fc , Silicon Dioxide/pharmacology , Thymoma/immunology , Thymus Neoplasms/immunologyABSTRACT
Human osteosarcoma cell lines T 1 and ZT 1 were analyzed for host origin. The results indicated that these lines must have been contaminated with rat x mouse hybrid cells. The isolated virus was identified as an avian sarcoma virus belonging to the C subgroup.
