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Biomedical subjects

J Caraux

Publications and source records attributed to J Caraux.

31 records · Page 2Linked to original sources
PubMed1980

Immune imbalance in cancer patients.

The immune status of the tumor-bearing patient remains poorly defined. In various solid-tumor-bearing patients, we demonstrated the absence of ADCC modifications in the patient in relapse or in evolution. These same patients presented a significant increase in immune complexes when compared with patients in remission. Furthermore, we noted a decreased NK activity, a decreased number of ARFC, corresponding to a helper T cell subpopulation, and a corollary increase in T-dependent suppressor activity. These results, on the whole, suggest an immune imbalance and that the helper cell-suppressor cell ratio should be investigated in greater depth within the context of the immune response in the cancer patient.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1980

Human K cell activity. I. Relation to effector cells buoyant density.

In order to disclose a relation between human K cell activity and effector cells buoyant density, this activity was tested, against antibody sensitized 51Cr labelled L1210 cells, in lymphocytes subsets obtained by centrifugation to equilibrium in discontinuous bovine serum albumin gradients. Since K cell activity is mainly present in null and T cells, this study focused on the buoyant density subsets of human T and null cells. Our results show that, in these T and null cells, K cell activity is directly related to cell density, the less dense fraction having the highest cytotoxic capacity. From the recovery of Lytic Units, it is shown that the K cell pool can be associated with the population of activated or precursor cells in human peripheral blood.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1979

Human autologous rosettes. II. Prognostic significance of variations in autologous rosette-forming cells in the peripheral blood of cancer patients.

The distribution of autologous rosette-forming cells (A-RFC) was determined in 55 samples of peripheral blood mononuclear cells from healthy adult donors and 407 samples from 112 cancer patients. The mean percentage and absolute number of A-RFC were significantly reduced in the cancer patients compared to the healthy adult donors. These values for A-RFC were even more significantly reduced in patients with cancer relapse than in patients with complete remission of cancer. Thus diminution of this pertinent subset of T-lymphocytes has interesting clinical value by its being closely related to an adverse prognosis.

Adolescent↗
PubMed1979

Thymosin modulation of suppressor function in mice and man.

The effect of thymosin on suppressor-cell function was evaluated in vivo in a murine tumor system and in vitro on human lymphocytes. In mice, the Lewis tumor system was used. We showed that splenocytes from tumor-bearing animals were able to enhance tumor growth in a syngeneic system. This enhancement was similar when thymocytes from tumor-bearing animals were used and disappeared after anti-Thy 1-2 antiserum treatment, suggesting a T-dependence. Treatment of the tumor-growth-enhancing lymphocytes with corticosteroids or irradiation caused this effect to disappear completely suggesting that the tumor-growth-enhancing T-lymphocytes were suppressor T-cells. Furthermore thymosin (fraction 5)-treated, tumor-growth-enhancing T-lymphocytes were not able to enhance tumor growth and even significantly decreased it. In the human system we showed that Con A-stimulated lymphocytes were able to suppress the response of normal lymphocytes to PHA, PWM, and Con A, and in MLC. This effect was significantly blocked in presence of thymosin fraction 5.

Animals↗
PubMed1979

Release of an Fc-binding component from normal or activated human lymphocytes.

Under cultivation at 37 degrees C in the presence or absence of Con A, human lymphocytes release a soluble component able to inhibit antibody-dependent cell-mediated cytotoxicity, EAG rosette formation and also able to hemagglutinate erythrocytes sensitized with a subagglutinating dose of IgG. These activities are selectively removed on Sepharose-aggregated-IgG or Sepharose-antigen-antibody complex, but not on Sepharose-(Fab') 2, suggesting the involvement of an Fc-binding component. These activities are not reversible by alpha-methyl-mannoside. As the appearance, in the supernatants of lymphocyte cultures, of such capacity to interact with the Fc portion of IgG is paralleled by a decrease in the capacity of such lymphocytes to form EAG rosettes or mediate antibody-dependent cell-mediated cytolysis, the isolated component might represent a soluble form of Fc receptor shed from the surface of human lymphocytes.

Animals↗
PubMed1979

Regulation of human suppressor cell function by thymosin.

Suppressor cells were induced in vitro by Con. A using human peripheral blood lymphocytes. Suppressor cell function was evaluated by mitogen stimulation (PHA and Con. A) and in mixed lymphocyte culture (MLC), Thymosin fraction V was able to block the effector phase more significantly than the induction phase of suppressor cell expression. This effect was additive if thymosin fraction V was present both during the induction and effector phases.

Concanavalin A↗
PubMed1978

Quantitative comparison of K cell potential in human T and null cells.

Using a short-term quantitative assay of the antibody-dependent cell-mediated cytotoxicity (ADCC) of human peripheral blood lymphocytes towards 51Cr-labeled mouse lymphoma cells, it is possible to estimate the relative involvement of various lymphocyte populations in the overall ADCC potential displayed by unfractioned lymphocytes. Lymphocytes were separated by means of an anti-F(ab')2 column combined with sedimentation of E rosette-forming cells or EA rosette-forming cells, and a discontinuous serum albumin gradient, and were characterized by several surface markers. ADCC results were expressed as the cytotoxic capacity of 10(6) cells of each population (lytic units/10(6) cells) as well as the cytotoxic potential of each population by taking into account their relative numerical sizes. Although the null cells had the highest cytotoxic capacity, highly purified T cells also disclosed a cytotoxic capacity which, because of the large numerical excess of T cells over null cells, could account for closely equivalent cytotoxic potentials of these two populations. ADCC was entirely abolished by further removal of Fc receptor-bearing-cells, in all the subsets studied. Our data underline the role that the small proportion of Fc receptor-carrying T cells might play in ADCC.

Animals↗
PubMed1975

Macrophage arming factor release by allografted mouse lymphocytes stimulated by phytohermgglutinin.

Spleen cells from a C57BL/6 mouse allografted with DBA/2 skin may release a macrophage arming factor when stimulated with phytohemagglutinin. This in vitro nonspecific release is observed only when the recipient cells are collected during a limited period preceding or coinciding with graft rejection. The phenomenon disappears if the skin allograft has been removed before cell collection. It appears if an i.v. injection of donor cells is given to the recipient after graft removal, on the day preceding cell collection. These data suggest that this in vitro apparently nonspecific macrophage arming factor release by phytohemagglutinin-stimulated recipient cells may in fact disclose a previous specific in vivo immune cell triggering by graft antigens.

Animals↗