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Biomedical subjects

D W Talmage

Publications and source records attributed to D W Talmage.

At least 55 records · Page 3Linked to original sources
PubMed1976

Failure of ovalbumin associated with allogeneic spleen ceels to stimulate proliferation of lymph node cells of immune mice.

Ovalbumin-pulsed spleen cells were found to stimulate thymidine uptake of lymph node cells of syngeneic mice immunized with ovalbumin in complete Freund's adjuvant after treatment of spleen cells with Mitomycin C but not after heating the spleen cells at 56degrees for 30 min. Ovalbumin-pulsed spleen cells of allogeneic mice failed to stimulate the immune lymph node cells more than unpulsed cells, although a net increase in the thymidine uptake above the allogeneic stimulation was observed when free ovalbumin was added to the mixed culture. To eliminate the high background of the mixed lymphocyte reaction, F1 mice were made chimeric with bone marrow of one of the parental strains. Using lymph node cells of the immunized chimeras, the stimulation by pulsed spleen cells was much greater when antigen was presented on cells of the parental strain used for bone marrow injection than when presented on cells of the other parental strain.

Animals↗
PubMed1975

Comparative immunochemical studies of primate hemoglobins.

The antigenic properties of a number of chromatographically purified primate hemoglobins were compared to those of normal human hemoglobin using a sensitive radioimmunochemical procedure. The degree of inhibition of the antigen-antibody reaction with heterologous hemoglobins appeared to be related to the structural similarity of these proteins to the normal human hemoglobin immunogen. With the exception of the baboon hemoglobin, the antigenicity of the hemoglobins paralleled the phylogeny of the primates. The gorilla and chimpanzee hemoglobins were antigenically identical to normal human hemoglobin, whereas the gibbon and orangutan hemoglobins were substantially more variable. Of the Old World monkey hemoglobins examined, the baboon produced lower inhibition values, suggesting a greater degree of structural dissimilarity than other Cercopithecoidea hemoglobins, which is compatible with a greater rate of evolutionary change occurring in this protein. Using the known amino acid sequences of human and other primate hemoglobins, we have attempted to identify antigenic determinant areas of the proteins.

Alouatta↗
PubMed1975

Is the macrophage the stimulating cell?

Using CAF1 spleen cells to stimulate parental strain BALB/c spleen cells in a mixed lymphocyte culture, column separation of responding cells increased their response whereas the same treatment of stimulating cells reduced their activity approximately 95 per cent. Peritoneal macrophages from CAF1 mice were found to stimulate BALB/c spleen cells poorly if present in comparable numbers or if they were cultured for 24 hours before adding responding cells. However, if the F1 macrophages were in contact with the BALB/c cells for only 4 hours, their stimulating effect was increased strikingly. Under these conditions BALB/c macrophages had no effect. It is concluded that the macrophage is probably the most effective stimulating cell and may be the only cell with this capability.

Animals↗
PubMed1975

Activation of T-lymphocyte helper function by brief exposure to antigen-pulsed macrophages.

In this report we investigated the ability of macrophage-associated OVA to stimulate purified OVA-immune T-lymphocytes to produce nonspecific helper activity for antibody production. T-cell activation required only a brief contact between the antigen-pulsed macrophages and T-lymphocytes and was maximal after a 4-hr contact. T-cell activation occurred at 37 but not at 4 degrees C, indicating that the macrophages and/or lymphocytes must be metabolically active for efficient activation. In addition, we compared the ability of antigen-pulsed syngeneic or allogeneic macrophages to activate T-cells for helper function.

Animals↗
PubMed1975

Regulation of the immune response: production of a soluble suppressor by immune spleen cells in vitro.

The addition of ovalbumin-immune spleen cells (Ova ISC) to sheep erythrocytes-immune spleen cells (SRBC ISC) in Mishell-Dutton-type cultures resulted in a dramatic reduction of PFC to SRBC and was dependent upon the addition of soluble Ova at low concentrations of Ova ISC. The suppressing cells in the Ova ISC were shown to be irradiation sensitive, depleted by anti-theta antiserum and complement treatment, and did not absorb to glass bead columns. Ova ISC-induced inhibition also occurred in culture chambers across a cell-impermeable membrane and a soluble inhibitor was recovered in chambers opposite the Ova ISC. This suppressor factor was sensitive to trypsin treatment and to heating at 80 degrees C, but not to 70 degrees C, for 30 min. The molecular weight, as determined by sucrose gradient analysis, was between 55,000 and 60,000 daltons. This suppressor factor appears to be distinct from a T-cell "helper" factor which was found to be sensitive to heating at 70 degrees C for 30 min. We propose that this suppressor factor participates in the termination of most immunologic responses and is responsible for the antigenic competition phenomenon.

Animals↗
PubMed1975

Antibody synthesis in synchronized mouse spleen cells during the secondary response to sheep erythrocytes in vitro.

Immunoglobulin synthesis by mouse spleen cells during the secondary response to sheep erythrocytes in vitro was examined in cells synchronized by methotrexate and adenosine treatment. Antibody synthesis by the synchronized cells was discontinuous through the cell cycle and highest in the early S phase. Previous results from this laboratory indicated that antibody secretion, as measured by plaque production to sheep erythrocytes, was also greatest in early S, and taken together these results suggest little difference in the expression of antibody synthesis and secretion through the cell cycle. Actinomycin D was employed in several experiments in an attempt to determine if the variation in antibody synthesis was regulated by transcription of messenger RNA for immunoglobulin. Lower actinomycin concentrations (0.05 mug/ml) reportedly permitting messenger, but not ribosomal, RNA synthesis as well as higher concentrations (1 mug/ml) rapidly reduced immunoglobulin and total protein synthesis. These results indicated that actinomycin was not suitable for determining the stability of messenger RNA in mouse spleen cells. Therefore, the reasons for fluctuation in antibody synthesis during the cell cycle could not be determined, but several possibilities are suggested.

Adenosine↗
PubMed1975

Inhibiton of tumor cell proliferation: second role for suppressor cells?

An antimitotic factor for mouse tumor cells was isolated from the supernatant fluids of antigen-stimulated ovalbumin-immune mouse spleen cells. A similar antimitotic factor was obtained from the supernatant fluids of phytohemagglutinin-stimulated non-immune spleen cells. The inhibitor prevented the multiplication of mouse L929 fibroblast cells in vitro and the in vivo proliferation of Ehrlich ascites tumor cells. Inhibition was not due to cytotoxic effects and the antimitotic effects were reversible. The antimitotic activity may be species-specific since the purified factor obtained from mouse spleen cells had no effect on human or monkey cell lines. This factor appears to be the same as the T lymphocyte-dependent suppressor for antibody production that we described previously. Several implications for the production of the suppressor in response to tumor cells that may be beneficial or harmful to the host are discussed.

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