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H Vie

Publications and source records attributed to H Vie.

28 records · Page 2Linked to original sources
PubMed1986

Decline, with age, in the proportion of mouse T cells that express IL-2 receptors after mitogen stimulation.

Receptors for IL-2 can be demonstrated on the majority of mouse splenic T cells within 48 h after stimulation with Concanavalin A. We show here that aging leads to a decline in the frequency of cells able to generate detectable levels of IL-2 receptor, as measured by cytofluorimetry using antibodies to the receptor. The age-associated deficit cannot be overcome either by increasing the mitogen dose, or by supplementing the cultures with exogenous IL-2. At least a part of the decline, with age, in T cell-mediated immunity may represent an inability of individual T cells to produce sufficient IL-2 receptor to enable them to reach the IL-2 dependent phases of their first cell cycle.

Aging↗
PubMed1986

Limiting dilution analysis (LDA) of cells responding to recombinant interleukin-2 without previous stimulation: evidence that all responding cells are lymphokine-activated potent effectors.

The relationship between peripheral blood mononucleated cells spontaneously bearing the IL-2 receptor (IL-2R) and cell cytotoxicity for the natural killer (NK)-sensitive K562 target cell line was investigated. For this purpose, three types of experiments were performed. (i) Positive selection of cells spontaneously bearing the IL-2R was carried out by culturing peripheral blood lymphocytes (PBL) in the sole presence of recombinant IL-2 (rIL-2). Cytotoxicity was assessed at Day 6 of the culture in a 4 hr cytotoxic assay. (ii) Negative selection was performed by complement mediated lysis using the B1.49.9 monoclonal antibody which is specific for the IL-2R. (iii) Limiting dilution analysis of non-adherent PBL was carried out in the presence of rIL-2 alone. The colonies obtained were divided and daughter colonies assayed for anti-K562 cytotoxicity in a 6 hr cytotoxic assay and for proliferation. The results show that: (i) a 6-day culture of human non-adherent PBL in the presence of rIL-2 alone leads to a sharp increase in anti-K562 cytotoxicity; (ii) depletion of B1.49.9 positive PBL strongly decreases cytotoxicity against K562 targets; (iii) limiting dilution analysis indicates that all colonies grown without activation in the presence of autologous serum and rIL-2 can mediate cytotoxicity against K562 targets, which is not the case when the starting population is activated. Thus, our data taken together strongly suggest that lymphocytes spontaneously bearing the IL-2R are directly involved in K562 lysis by fresh PBL (classical NK activity). Moreover, we demonstrate that all colonies able to proliferate without any activation, in the sole presence of rIL-2, are potent K562 killers (in this case, these cells correspond to the so-called lymphokine activated killers, LAK).

Adult↗
PubMed1985

Defect in lectin-induced interleukin 2 (IL-2) production by peripheral blood lymphocytes of patients with Hodgkin's disease.

Peripheral blood lymphocytes (PBL) of patients with Hodgkin's disease were studied for their capacity to produce interleukin 2 upon in vitro phytohemaglutinin stimulation in the presence or absence of either interleukin 1 or indomethacin (2 micrograms/ml); eight patients were studied at the discovery of their disease before receiving any therapy (onset HD; OHD). Seventeen patients were tested in long-term (greater than 3 yr) remission (remission HD; RHD); most RHD were treated with both chemotherapy and irradiation. Fourteen healthy individuals served as controls. PBL from OHD have a significant (P less than 0.01) defect in the production of PHA-induced IL-2. Indomethacin and IL-1 had no effect on IL-2 yield. PBL from RHD yield intermediate levels of IL-2, which are nevertheless significantly lower (P less than 0.02) than control values. RHD recover the capacity of normal PBL to increase their production of IL-2 in indomethacin-supplemented culture medium. Interestingly, PHA responsiveness was significantly decreased only in RHD, thus not explaining the low IL-2 yield obtained in supernatants. In addition, 4-day PHA-blasts from both HD patients and control individuals increase their thymidine incorporation in the presence of purified lectin-free IL-2 to a similar degree, suggesting that their IL-2 receptors are unimpaired. Finally, OHD sera significantly inhibit PHA-induced IL-2 yield of normal PBL, suggesting that a seric component(s) may play a role in some cases. We conclude that defective IL-2 production may play a role in the well-documented deficient cellular immunity seen in Hodgkin's disease.

Adolescent↗
PubMed1985

Interleukin 2 production by peripheral blood lymphocytes in allograft recipients during acute rejection episodes.

In this study we investigate the relationship between the Interleukin 2 (IL-2) yield produced by kidney allograft recipient's peripheral blood lymphocytes (PBL) under lectin stimulation and the occurrence of acute rejection episodes. PBL were harvested prospectively before grafting, after grafting in steady-state period, and at the onset of acute rejection episodes. In addition, we tested retrospectively the ability of PBL of recipients engrafted for more than 1 yr to produce IL-2. IL-2 levels were assessed on the IL-2-dependent CTL-L2 murine cell line. Our data show: 1) before grafting, hemodialysed patients (N = 14) produced normal IL-2 yield compared with healthy donors (N = 21); 2) the IL-2 secretion of PBL of recipients with good graft function (N = 18) is decreased markedly during roughly the first 12 months following transplantation (P less than 0.01); 3) when acute rejection crisis occurred during this time period (N = 24), a sharp and highly significant increment (P less than 0.01) in lectin-induced IL-2 production of recipient's PBL was seen. After 1 yr, the capacity to secrete IL-2 upon lectin stimulation tends to be restored. Finally, our data correlate rejection and high PBL-IL-2 secretion clearly at a time when recipients with well-functioning grafts have markedly impaired IL-2 secretion.

Graft Rejection↗
PubMed1985

T cell colony-forming frequency of mononucleated cells extracted from rejected human kidney transplants. Functional and phenotypic studies of the colonies.

One line of investigation of cellular events leading to rejection of an allograft has been to collect the cells infiltrating the rejected allograft and to subject them to in vitro functional and cell marker analysis. Outlined in this article is a description of the limiting dilution analysis technique applied to mechanically disrupted cells obtained from three different rejected human kidney allografts and a phenotypic cell surface marker, as well as a functional study of the progeny of such cells at a clonal level. Of the harvested cells, 65% were T11+, 58% were OKT8+, and 14% were OKT4+. The frequencies of colony forming cells (CFC) were assessed in liquid medium supplemented with lectin-free purified IL-2 (selecting in vivo activated cells) or with IL-2 plus PHA. The CFC frequencies ranged from 1/777 to 1/120 cells plated and from 1/250 to 1/90 cells plated in, respectively, IL-2 and IL-2 plus PHA. Only colonies with a probability of monoclonality more than 80% were further expanded in the presence of lectin-free IL-2. Among 31 colonies grown in the presence of IL-2 alone, all colony-cells were OKT11+, 4/31 were T4+T8-, 24/31 T4-T8+--and, finally, 3/31 were T4+T8+. On the other hand, 122 colonies grown in the presence of IL-2 plus PHA were also all OKT11+, but 47/122 were T4+T8-, and 62/122 were T4-T8+. In addition, expression of DR molecules was highly variable from colony to colony. Significant antidonor cytotoxicity was recorded in 24 colonies, most of them expressing T8 molecules at their surface. Moreover cytotoxic antidonor colonies seemed to recognize an antigen determinant different from the known HLA incompatibilities between donor and recipient. In three long-term-cultured colonies, we noticed a shift in surface marker: from the expression of T8 to either the coexpression of T4 or the loss of the T8 to the sole expression of the T4 molecules. This methodology is a step forward in the elaboration of techniques for determining the relationships between the surface marker identity and the immune function of cells activated in vivo, which are found in a rejected human kidney.

Adult↗
PubMed1985

Increased interleukin II production during kidney allograft rejection.

We have studied the lectin-induced production of Interleukin II (IL-2) by peripheral blood leucocytes (PBL) obtained from recipients of kidney grafts. Pre-graft values (haemodialysed patients) are similar to those of healthy individuals. After grafting and during the first year the IL-2 levels produced by PBL from recipients with well functioning grafts are very low (p less than 0.001). Years after grafting the IL-2 yields tend towards restoration. At the onset of an acute rejection the IL-2 production rises significantly. These data show that an increase in IL-2 production may play a role in the rejection process.

Graft Rejection↗
PubMed1984

Preparative two-step purification of human IL-2 by HPLC and hydrophobic affinity chromatography.

Interleukin 2 (IL-2) has been purified by a protocol using gel filtration high performance liquid chromatography (HPLC) and hydrophobic affinity chromatography with blue-trisacryl M. Peripheral blood lymphocytes or tonsillar lymphocytes were stimulated with phytohemagglutinin (PHA). Serum free conditioned medium (CM) containing IL-2, other lymphokines and residual PHA molecules was analyzed after 3 variations of ammonium sulfate (AS) precipitation: (1) precipitation of CM with 50% AS yielded a precipitate containing most of the residual PHA but also a fraction of IL-2. (2) Precipitation with direct 80% AS of crude CM yielded both IL-2 and residual PHA. (3) A double step procedure (50% AS followed by 80% AS) yielded a precipitate containing IL-2 but free of residual lectin. HPLC purification of these various AS-precipitated materials or of lyophilized crude CM yielded 2 peaks with mitogenic activity as assayed with the CTLL2 murine clone or IL-2-dependent human Con A-stimulated lymphoblasts. IFN was easily separated from IL-2 and PHA, but BCGF still copurified with IL-2. Peak I (25 kDa) was enriched 400-fold for IL-2 while peak II (68 kDa) contained the residual PHA. The IL-2-containing fractions eluted from HPLC were further purified by blue-trisacryl M chromatography. The IL-2 eluted with 0.4 M NaCl. The entire protocol (HPLC followed by blue-trisacryl) led routinely to 8000-fold IL-2 enrichment. Preparative HPLC directly applied to lyophilized crude (CM) enriched IL-2 activity 400-fold with yield averaging 60% of the IL-2 input. The final material was free from interferon and IL-1, but BCGF still copurified with IL-2. The 2-step purified material (HPLC and blue-trisacryl) gave 2 bands in SDS-PAGE both of which contained IL-2.

Ammonium Sulfate↗
PubMedDate not supplied

[Inhibition of NK activity by oses: effect of interleukin 2 (author's transl)].

Several sugars can strongly inhibit the natural cytotoxicity (NK) exhibited by peripheral blood lymphocytes (PBL) against tumour cells. The inhibition of NK cytotoxicity mediated by mannose, glucose, galactose and saccharose was tested in human PBL. All these sugars significantly blocked (P less than 0.01 at 50 mM concentration) the NK cytotoxicity. The blocking is dose-dependent in a linear pattern. The sole preincubation of the attacking (NK) population is required for inhibition of cytotoxicity; no influence of the sugars were noticed on the K562 alone. In contrast, the NK cytotoxicity of PBL primed in mixed lymphocyte reaction and further cultured in presence of conditioned medium (CM), showed, aside of a clear increase (average 40% increase of specific 51Cr release, P less than 0.05) a full insensitivity to the tested sugars. Phytohaemagglutinin (PHA), interferon (IF) and an interleukin 2 (Il2) are contained in the CM. We showed that neither the PHA nor the IF preincubation of the cells can induce the insensitivity of NK for the sugars, thus our data strongly suggest that Il2 is implicated in the sugar insensitivity of the cytotoxicity of lymphocytes cultured with CM.

Adult↗