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Biomedical subjects

A Eisenthal

Publications and source records attributed to A Eisenthal.

42 records · Page 3Linked to original sources
PubMed1982

The in vitro generation of suppressor lymphocytes involves interactions between PNA+ and PNA- thymocyte populations.

Employing cell fractionation with the aid of peanut agglutinin, it was found that at least two subpopulations of T cells are required for the generation of suppressor T lymphocytes in culture. The co-operation of these two subpopulations, the medullary and the cortical types of thymocytes, is required for the induction phase but it apparently plays no role in the expression of the suppressive effect. With the aid of genetic markers, it was found that in medullary-type, cortisone-resistant, PNA-negative T cell was the progenitor of the suppressor lymphocytes, while the cortical type cells performed an accessory (regulatory?) function. Finally, it was observed that allostimulation of T cells in culture give rise to both 'helper' and suppressor cells. The generation of 'helper' lymphocytes requires allostimulation for less than 24 hr while the induction of suppressor cells requires a longer period of stimulation which leads in the end to predominance of the suppressor effect.

Animals↗
PubMed1979

Studies of allospecific suppressor cells in culture.

Allospecific suppressor T cells can be generated by allostimulating thymus, spleen and lymph node cells in culture. Bone marrow cells do not yield suppressor lymphocytes. While the efficiency of thymocytes for suppressor cell generation decreases with the age of thymus donors, the efficiency of spleen increases with age. Generation of suppressor lymphocytes depends on cell replication and protein synthesis. The suppressor function as such does not require cell replication. Induction of suppressor T cells in culture requires cell to cell interaction of cortical type and medullar type T cells.

Animals↗
PubMed1979

The generation of an allospecific suppressor factor in culture.

When mouse spleen cells were stimulated by irradiated allogeneic cells in a mixed lymphocyte culture for 96 hours, allospecific suppressor cells were generated that could inhibit the replicative processes when transferred to another MLR. When the primed cells were purified on Ficoll and incubated alone for another 24 hours, they released into the medium a subcellular factor which could also suppress MLR allospecifically. Evidence is provided that the cells which generate this factor arise by cooperation of at least two types of T-lymphocytes, one of which is the progenitor of the suppressor cell and the other an essential accessory cell. Adherent cells were shown to be also essential for the priming of suppressor lymphocytes.

Agglutinins↗
PubMedDate not supplied

Cross linking of anti-B16 melanoma monoclonal antibodies to lymphokine activated killer (LAK) cells: possible role in the therapy of B16 melanoma.

We have cross-linked, using succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) as a heterobifunctional reagent, anti-B16 melanoma monoclonal antibody to lymphokine activated killer (LAK) cells, independent of the Fc receptor. The conditions of such linkage were optimized so that the cytotoxic properties of LAK cells, as measured in a 4 h chromium release assay against fresh tumor cells, were preserved. Using the techniques described here, covalent cross linking of anti-B16 antibody to LAK cells preserved the reactivity of this antibody to antigens on B16 melanoma cells, and preserved the cytotoxic properties of the antibody-bound LAK cells to lyse B16 tumor cells and other tumor cells in vitro. Cross-linking antibody remained active on the surface of LAK cells for as long as 24 h after the completion of binding. Treatment of established B16 melanoma pulmonary or subcutaneous (s.c.) tumors with LAK cells cross-linked to anti-B16 melanoma monoclonal antibody did not significantly alter their therapeutic efficacy over untreated cells. The possible explanations for these in vivo observations and suggested approaches to increase the efficacy of the cross-linked LAK cells are discussed.

Animals↗