dinitrobenzenes and Cell-Transformation--Viral

In this study we test the hypothesis that immortalized adult rat Sertoli cells respond to known testicular toxins in a similar manner to Sertoli cells tested in vivo and in primary culture. This cell line was developed by immortalizing adult rat Sertoli cells with the temperature-sensitive mutant of SV40, ts255, such that the cells proliferate at the permissive temperature of 33 degrees C but express differentiated characteristics at the nonpermissive temperature of 40 degrees C. Confluent monolayers, grown at 33 degrees C or 40 degrees C, were exposed to a range of concentrations of dinitrobenzene (DNB) or dinitrotoluene (DNT) isomers or to cadmium chloride. Cellular response was assessed by neutral-red cell viability assay and ultrastructural changes. Cells grown at 40 degrees C were sensitive to lower concentrations of each toxicant than were cells grown at 33 degrees C. 1,2-DNB was more toxic than 1,3-DNB, and 3,4-DNT was more toxic than 2,4-DNT, as judged by the neutral-red cell viability assay. Ultrastructurally, cells treated with 1,2-DNB or 2,4-DNT showed increased numbers of autophagic vesicles compared to controls. Intercellular penetration of ruthenium red demonstrated breached tight junctions in 1,2-DNB and cadmium-treated cells. From these observations, we conclude that this cell line can serve as a model for studying toxic mechanisms in adult Sertoli cells.

Topics: Animals; Cadmium Chloride; Cell Division; Cell Line, Transformed; Cell Survival; Cell Transformation, Viral; Dinitrobenzenes; Male; Microscopy, Electron; Rats; Sertoli Cells; Simian virus 40; Temperature

Antigen-specific immune T lymphocytes of male C57BL/6 mice were enriched in vitro on monolayers of antigen-pulsed syngeneic macrophages. The cells were treated in vitro with RadLV and inoculated intrathymically into irradiated female C56BL/6 animals. Thymomas arising in the inoculated recipients were characterized as donor- (male) type according to their karyotype. In vivo and in vitro cell lines were established from the primary lymphomas, two of which (designated ROT/6.1 and ROT/6.2) were capable of providing antigen- (carrier) specific help in normal or preimmunized mice. None of the lymphomas could induce antigen-specific DTH reaction. Five months after their establishment, ROT/6.2 alone retained its carrier specificity. ROT/6.2 consisted mainly of Lyt-1+ cells, whereas the ROT/6.1 population was more heterogeneous and contained Lyt-1+, Lyt-2+, and Lyt-3+ cells. The carrier specificity of the latter may have been lost due to selection against the specific helper cells during prolonged passages.

Topics: Animals; Antigens, Ly; Cell Line; Cell Transformation, Viral; Dinitrobenzenes; Epitopes; Female; Genetic Carrier Screening; Hypersensitivity, Delayed; Leukemia Virus, Murine; Leukemia, Experimental; Leukemia, Radiation-Induced; Male; Mice; Mice, Inbred C57BL; Ovalbumin; T-Lymphocytes; Thymoma

T cells were isolated from spleens of C57BL/Ka/Thy 1.1/Lb mice immunized with 2,4-dinitrophenylated keyhole limpet hemocyanin (DNP-KLH). The mice were infected in vitro with radiation leukemia virus and injected intrathymically into congenic C57BL/Ka (Thy 1.2) recipients. Within 3-4 months, seven thymic lymphomas developed, five of which were of donor type. The donor lymphomas were explanted and permanent cell lines were established in vitro. These lymphoma cells are capable of providing antigen-specific carrier (KLH)-primed help to DNP-primed B lymphocytes in secondary antibody production to DNP-KLH. They also enhance the secondary antibody response of whole period spleen cell populations to DNP-KLH. The availability of these immortal clonable populations of immunofunctional neoplastic T lymphocytes should facilitate biological and biochemical investigations of lymphocyte interactions during synthesis of antibody to thymus-dependent antigens.

Topics: Animals; Antibody Formation; Carrier Proteins; Cell Line; Cell Transformation, Viral; Dinitrobenzenes; Epitopes; Immunologic Memory; Leukemia Virus, Murine; Leukemia, Experimental; Lymphocyte Cooperation; Lymphoma; Mice; T-Lymphocytes