Biomedical subjects

B Susskind

Publications and source records attributed to B Susskind.

5 recordsLinked to original sources

PubMed1991

A cytotoxic T-lymphocyte clone derived from mice with progressively growing tumors.

Tumor-specific T-cell clones were derived from spleen cells of mice bearing a syngeneic PHS-5 tumor (a P815 mastocytoma mutant). Cells were expanded in vitro and characterized and assayed for activity against the relevant tumor in vivo. Clone cells were CD4-, CD8+ T lymphocytes, as determined by fluorescence activated cell sorting analysis and were specifically cytotoxic against P815 tumor cells in vitro, as shown in chromium 51 release assays. These cells require both antigen and interleukin 2 to proliferate; neither alone is sufficient, even with the addition of interleukin 1. In an experimental P815 liver metastasis model, the adoptive transfer of GD11 or GD11.17 clone cells and injection of recombinant interleukin 2 (7500 U intraperitoneally) 3 days after infusion of tumor cells reduced the number of tumor nodules, while the adoptive transfer of lymphokine-activated killer cells was ineffective.

Animals↗

PubMed1985

Modulation of in vitro cellular immune response by histamine agonists or antagonists in murine species.

The generation of secondary cytotoxic T-lymphocyte (CTL) responses in vitro toward allogeneic P815 mastocytoma cells were suppressed 60-80% when 10(-4) mol/l histamine, 10(-5) mol/l dimaprit (S-[3-(N,N-dimethylamino) propyl]isothiourea dihydrochloride) or 10(-5) mol/l impromidine were present in the culture. Three lines of evidence suggest this observation was a result of an active suppression mechanism and not a result of drug toxicity: Control level activity was obtained when Interleukin-2/T-cell growth factor (IL-2) containing supernatants were added to suppressed cultures. Removal of drug after incubation resulted in control level responses upon reculture. The addition of these H2 agonists to spleen cells from nonimmune animals did not affect the primary CTL response to P815. The effects of H1 and H2 antagonists were also tested in this model. The observed suppression was abrogated by the H2 antagonists cimetidine and mifentidine but not by the H2 antagonist ranitidine nor H1 antagonists, chlorpheniramine, pyrilamine or diphenhydramine. These results suggest regulation of CTL differentiation to alloantigens can be modulated by H2 reactive entities.

Animals↗

PubMed1982

Immunoenhancing activity of NPT 15392: a potential immune response modifier.

NPT 15392, a new immunomodulating compound related to inosine in structure and isoprinosine in action, enhances T-cell dependent immune responses. Antibody responses to sheep red blood cells are augmented two to threefold in mice receiving NPT 15392 while T-cell independent antibody responses to TNP-LPS are unaffected. NPT 15392 does not enhance or alter the number of clonable B cells. This drug also increases cytotoxic T-lymphocyte responses to allogeneic tumor cells but does not alter the number of cytotoxic precursor cells. Immature hematopoietic cell classes (clonable progenitor cells) were also monitored and found not to be influenced by NPT 15392.

Adjuvants, Immunologic↗

PubMed1982

Choices.

Explore the source record for details and available documents.

Adult↗

PubMed1977

An energy-conserving pyruvate-to-acetate pathway in Entamoeba histolytica. Pyruvate synthase and a new acetate thiokinase.

Under anaerobic conditions, cells of Entamoeba histolytica grown with bacteria produce H2 and acetate while cells grown axenically produce neither. Aerobically, acetate is produced and O2 is consumed by amebae from either type of cells. Centrifuged extracts, 2.4 x 106 x g x min, from both types of cells contain pyruvate synthase (EC 1.2.7.1) and an acetate thiokinase which, together, form a system capable of converting pyruvate to acetate. Pyruvate synthase catalyzes the reaction: pyruvate + CoA leads to CO2 + acetyl-CoA + 2E. Electron acceptors which function with this enzyme are FAD, FMN, riboflavin, ferredoxin, and methyl viologen, but not NAD or NADP. The amebal acetate thiokinase catalyzes the reaction acetyl-CoA + ADP + Pi leads to acetate + ATP + CoA. For this apparently new enzyme we suggest the trivial name acetyl-CoA-synthetase (ADP-forming). Extracts from axenic amebae do not contain hydrogenase, but extracts from cells grown with bacteria do. It is postulated that in bacteria-grown amebae electrons generated at the pyruvate synthase step are utilized anaerobically to produce H2 via the hydrogenase and that the acetyl-CoA is converted to acetate in an energy-conserving step catalyzed by amebal acetyl-CoA synthetase. Aerobically, cells grown under either regimen may utilize the energy-conserving pyruvate-to-acetate pathway since O2 then serves as the ultimate electron acceptor.

Acetate-CoA Ligase↗