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J Bertoglio

Publications and source records attributed to J Bertoglio.

At least 73 records · Page 4Linked to original sources
PubMed1988

Generation of lymphokine-activated killer cells: synergy between tumor necrosis factor and interleukin 2.

Large granular lymphocytes (LGL) can be activated by interleukin 2 (IL-2) to lymphokine-activated killers (LAK). The effect of tumor necrosis factor (TNF) on LAK generation was investigated. TNF was found to act synergistically with low concentrations of IL-2 (0.10-0.25 ng/ml), which were ineffective by themselves in inducing LAK activity, to promote the differentiation of LGL into non-major histocompatibility complex-restricted killers. When IL-2 was used at concentrations optimal for LAK generation, TNF did not further enhance this phenomenon. Specific binding of 125I-labeled TNF to LGL was increased by IL-2 stimulation. Scatchard analysis of TNF binding revealed the existence of two classes of binding sites with markedly different affinities (Kd values of 57 and 600 pM). We also demonstrated that the IL-2/TNF synergistic induction of LAK activity did not involve either IL-1 or interferon-gamma. This IL-2/TNF synergistic effect was blocked by anti-Tac antibodies. Immunofluorescence analysis revealed that IL-2/TNF selectively up-regulated Tac antigen expression on LAK precursors. Our results suggest a functional interaction between IL-2 and TNF on LAK precursors, which results in a reduction of the IL-2 concentration required for differentiation of LGL into LAK killers.

Drug Synergism↗
PubMed1988

[Functional interaction between the tumor necrosis factor and interleukin 2 during induction of lymphokine activated killer cytotoxic activity].

TNF has a differential effect on the induction of LAK activity which is dependent on the IL-2 concentrations used for LGL stimulation. TNF was found to synergize with low concentrations of IL-2 which are normally ineffective in inducing LAK activity. When IL-2 was used at concentrations optimal for LAK generation, TNF did not further enhance the differentiation of LGL into LAK effectors. When anti-TNF was included in the 51Cr-release assay, no effect on the cytolytic activity was observed. We also demonstrate that IL-2 induced an increase of specific TNF binding to LGL.

Dose-Response Relationship, Drug↗
PubMed1987

Epstein-Barr virus-containing B-cell line produces an interleukin 1 that it uses as a growth factor.

We report the establishment of a spontaneous interleukin 1 (IL-1)-producing subclone derived from the human Epstein-Barr virus (EBV)-containing B-lymphoblastoid cell line (721 LCL) and show that the IL-1 produced by this B-cell subclone is distinct from other types of IL-1. The parental cell line 84.5, a deletion mutant of the 721 LCL cell line, can be induced to produce IL-1 activity when stimulated by certain inducers such as phorbol 12-myristate 13-acetate in the presence of fetal calf serum. From this parental 721/84.5 clone, a subclone, termed 3B6, has been developed. This 3B6 subclone has an immature B-cell phenotype, expresses only HLA class II DP subregion antigens, and spontaneously releases IL-1 in the culture supernatant with relatively few inhibitory molecules under serum-free culture conditions. The 3B6-derived IL-1 was purified from 3B6 conditioned medium with a three-step procedure. The molecular weight of this IL-1 is 13,500, and the isoelectric point values are pH 4.9 and 5.1 without any component focusing near pH 7. The N-terminal amino acid sequence differs markedly from those reported for the two IL-1 species produced by monocytes. The purified material shares several biological properties with monocyte IL-1, since it could induce the proliferation of murine thymocytes, the production of interleukin 2 by phytohemagglutinin-stimulated cloned HSB2 T cells, and the proliferation of human fibroblasts. However, this IL-1 activity could not be blocked by polyclonal anti-monocytic IL-1 antibodies, and, more importantly, it was not pyrogenic in rabbits. Finally, it promotes the growth of B-cell clones derived from the parental 721/84.5 lines in the absence of fetal calf serum, which suggests that it could act as an autocrine growth factor in this Epstein-Barr virus-transformed B-cell line.

B-Lymphocytes↗
PubMed1986

Purification to homogeneity and NH2-terminal amino acid sequence of a novel interleukin 1 species derived from a human B cell line.

A subclone, referred to as 3B6, derived from a DR-negative EBV-transformed B cell line, has been found to spontaneously produce IL 1. 3B6-IL 1 displays a pI of 5 on FPLC chromatofocusing. It has been purified to homogeneity by a sequence of ion-exchange chromatography and affinity chromatography on procion red agarose. The homogeneous material migrated with an apparent m.w. of 13,500 on SDS-PAGE. The overall recovery of IL 1 activity was estimated at 57%. The final material had a specific activity of 7.8 X 10(6) half-maximal units/mg and represented a 50,000-fold purification. A partial NH2-terminal amino acid sequence has been obtained that is different from those reported from monocytic IL 1. However, this molecule can formally be identified as IL 1 on its spectrum of biologic activities. In addition to inducing the proliferation of murine thymocytes in the co-stimulator assay. 3B6-IL 1 is active on both human T and B cells, respectively, in inducing IL 2 synthesis by cells from a subcloned HSB 2 line and promoting the proliferation of anti-IgM-stimulated human peripheral blood B lymphocytes. Furthermore, 3B6-IL 1 acts as a growth factor for normal human fibroblasts and for the 3B6 line itself. However, 3B6-IL 1 is not pyrogenic in rabbits. Thus, the 3B6 cell line was shown to produce a new molecular species of IL 1, with respect to its NH2-terminal sequence, which shared all of the studied biologic activities of monocytic IL 1 except for pyrogenicity.

Amino Acid Sequence↗
PubMed1986

Interleukin 2 (IL 2) up-regulates its own receptor on a subset of human unprimed peripheral blood lymphocytes and triggers their proliferation.

Several reports indicate that human peripheral blood lymphocytes (PBL) seeded in culture with purified or recombinant interleukin 2 (IL 2) immediately after separation from the blood display a substantial level of proliferation at day 5 or 6, even in the absence of any activating signal. The spontaneously IL 2 proliferating cells are large lymphocytes, and they co-purify on a Percoll gradient in the large granular lymphocytes (third (LGL) fraction) together with the natural killer (NK) activity. When LGL were separated into NKH1 (an NK-specific surface marker)-positive and NKH1-negative cells by fluorescence-activated cell sorting (FACS), proliferating cells were mainly found in the NKH1-negative fraction. On the contrary, when cells from Percoll fraction 3 were separated into OKT3-negative and positive cells, the majority of the proliferating cell was found in the OKT3-positive cells. These results indicate that spontaneously IL 2 proliferating (SIP) cells most probably belong to the T cell lineage, but are distinct from NK cells. Surprisingly, cells from this Percoll fraction examined immediately after separation from the blood do not express detectable amounts of IL 2 receptors as assessed by three different techniques: binding of [3H]IL 2, binding of [125I]anti-Tac antibodies, and FACS analysis with the use of anti-Tac antibodies. However, after 18 hr of culture in IL 2-supplemented medium, 5 to 7% of these cells became Tac-positive by FACS analysis. Additional analysis of IL 2 receptor induced in culture with IL 2 was performed by [125I]anti-TAC binding and by [3H]IL 2 binding. Scatchard analysis of [3H]IL 2 binding, in the range of concentrations leading to the detection of high-affinity binding sites, showed an affinity constant similar to that of conventional phytohemagglutinin blasts. The role of IL 2/IL 2 receptor interaction in the proliferation process was confirmed by the fact that proliferation, in contrast with NK activation, was clearly inhibited by anti-Tac antibodies. When LGL activated with IL 2 for 60 hr were sorted into Tac+ and Tac- cells, equal levels of NK activity was found in the two fractions. Proliferation, however, was only observed in the Tac+ population. We interpret these results to indicate that SIP cells are preactivated cells circulating in the blood. They are large cells and represent a very small proportion of circulating lymphocytes (0.3%). They express a subliminal amount of IL 2 receptor. Cultivated in the presence of IL 2, IL 2 receptor expression is enhanced to a detectable level, and the SIP cells begin to proliferate. These SIP cells could be activated T cells present in every normal individual.

Antibodies, Monoclonal↗
PubMed1985

IL 2 receptor induction on human T lymphocytes: role for IL 2 and monocytes.

In this report we studied the requirements for the activation and proliferation of highly purified human T lymphocytes. Purified T cells incubated for 3 days with PHA neither proliferate nor express IL 2 receptors as detected by FACS analysis with the use of anti-Tac antibodies. However, purified T cells incubated with Con A or anti-T3 moAb do not proliferate, albeit 30 to 35% T cells express Tac epitopes. The addition of IL 2, either natural purified or recombinant, resulted in both the appearance of Tac antigen and the proliferation of PHA-activated T cells. Much to our surprise, IL 2 did not induce proliferation of Tac-positive T cells activated by Con A or soluble anti-T3 unless monocytes were added to the cultures. These data suggested that two classes of IL 2 receptors might exist on T cells, one of which was not functionally involved in T cell proliferation. In keeping with this interpretation, we have been able to demonstrate, using a radiolabeled IL 2 binding assay, that anti-T3 moAb induced almost exclusively IL 2 receptors of low affinity (Kd = 30 to 70 X 10(-9) M) and that additional signals, provided by monocytes, are required for the acquisition of high affinity receptors. IL 2 itself can induce high affinity receptors on PHA-stimulated T cells but not on cells activated by Con A or anti-T3. In this latter case the physical presence of monocytes is required and cannot be substituted by IL 1, thus indicating a previously unreported role for monocytes. It is postulated that the contact of monocytes with T cells induces a switch from an inactive low affinity conformation of the IL 2 receptor to a functional high affinity one.

Adult↗
PubMed1982

Chromatofocusing as a tool for the characterization and partial purification of human interleukin-2.

Human interleukin-2 (IL2) has been characterized and partially purified with a sequence of chromatofocusing, gel filtration and SDS-PAGE analysis. IL2 when tested in a [3H]thymidine incorporation assay by human IL2-dependent T cells, appeared to have a MW of 25,000 as determined by Ultrogel ACA 54 gel filtration. Chromatofocusing of an 80% ammonium sulfate precipitate from crude conditioned medium yielded 4 peaks of activity corresponding to fractions of pH 7.65, 7.28, 6.72 and 6.58. Neuraminidase treatment of IL2 prior to chromatofocusing reduced its charge heterogeneity to a single peak of activity at pH 7.63. IL2 which had been treated with neuraminidase, purified by chromatofocusing, radioiodinated and further separated by gel filtration was subjected to SDS gel electrophoresis. We observed a band, migrating in the 15,000 region which only occurred in the active fractions and which we tentatively identified as IL2. These findings indicate that the purification procedure described is appropriate to the characterization and preparation of quantities of human IL2.

Chromatography, Gel↗
PubMed1981

EBV-positive Burkitt's lymphoma from Algeria, with a three-way rearrangement involving chromosomes 2, 8 and 9.

Burkitt's lymphoma was diagnosed in male Algerian child presenting with abdominal and jaw tumours. Viral studies revealed that this non-endemic case was associated with the Epstein-Barr virus. Cytogenetic examination of tumour cells showed a complex three-way rearrangement involving chromosomes 2, 8 and 9. Our report indicates that, in Burkitt's lymphoma, not only simple but also complex translocation involving chromosome 8 may arise. This finding in a North African case emphasizes the need for more detailed study of the clinical, virological and cytogenetic features of Burkitt's lymphoma throughout the world.

Burkitt Lymphoma↗
PubMed1981

Cultured T lymphocytes cytotoxic for a syngeneic lymphoma: derivation in Con A-conditioned medium and in vivo activity.

Cultures of murine T lymphocytes with cytotoxic activity towards syngeneic RBL-5 lymphoma cells were obtained from spleen cells of immunized animals after co-culture in vivo with irradiated RBL-5 cells. At different times after initiation, these mixed tumour-lymphocyte cultures (MTLC) were multiplied by transfer to conditioned medium (CM) containing T cell growth factor (TCGF) activity, produced by the stimulation of rat spleen cells with Con A. The effect of residual Con A was investigated by the addition of specific blocking sugar, alpha-methyl mannoside (alpha MM), to the CM in some experiments. This procedure did not reduce the growth potential of the cells, and resulted in a dramatic increase in the cytotoxic activity of the cultures as measured by a 4-hr 51Cr-release assay. The cultures multiplied 1 X 10(3)-fold over a 3-week period with retention of cytotoxicity for RBL-5 cells at levels up to 70-fold greater than those of the MTLCs from which they were derived. The cultured cells, when injected i.p. together with RBL-5 cells into normal mice, were shown to mediate a significant prolongation of the survival of the treated animals. This effect was, however, less dramatic than had been expected from the in vitro results. It would therefore appear that, while cells grown in tissue culture using Con A-conditioned medium may fulfill some theoretical requirements for the immunotherapy of experimental tumours, other factor(s) are required for full protection.

Animals↗
PubMed1979

Mouse erythrocyte rosette formation by human lymphoid cell lines.

Lymphoid cell lines have been studied with respect to mouse erythrocyte rosette formation, a marker for B cells. Cells from six B-cell lines out of fifteen tested were able to form mouse erythrocyte rosettes. When this capacity was studied after neuraminidase pretreatment of the cells, it defined three groups of B lymphoid cell lines according to their reactivity. However, these groups could not be correlated to any of the other B-cell markers, and especially mouse erythrocyte rosette formation appeared unrelated to the class of the immunoglobulin present on the cell surface. Non B-cell lines were never found to form such rosettes. The capacity of B-cell lines to form mouse erythrocyte rosette was further demonstrated to be relatively insensitive to trypsin treatment, and results are presented suggesting some degree of cell cycle dependency of the expression of this marker.

B-Lymphocytes↗
PubMed1979

Detection of HLA-DRw (Ia-like) antigens on human T lymphocytes grown in tissue culture.

Human T lymphocytes that proliferate in the presence of conditioned medium from PHA-stimulated allogeneic peripheral blood cells were shown to express IPA antigens after the 8th culture day. Ia antigens as detected by xenogeneic antisera were present on 80 to 90% of the cultured cells which were also strongly reactive with xenogeneic antisera defining a human T cell antigen and formed E rosettes. Control cultures with PHA or no conditioned medium expressed T cell but not Ia antigens. These cultured T cells also express the same HLA-DRw determinants as the B cells of the donor they were derived from. Absorption of xenogeneic Ia, and HLA-DRw alloantisera with cultured T cells completely removed the reactivity of these sera for enriched peripheral blood B lymphocytes from normal donors.

Animals↗
PubMed1977

Mouse red cell rosette formation by subpopulations of human lymphocytes.

In six separate experiments, 7-2% of purified peripheral blood lymphocytes from normal donors were shown to form rosettes with mouse erythrocytes. Normal T and B lymphocytes were separated according to their membrane properties, by E-rosette formation or fractionation on anti F (ab')2 column. The results obtained in both the separation procedures used were in good agreement: T lymphocytes were never found to form mouse red cell rosettes. On the contrary, enrichment of suspensions in B lymphocytes resulted in an increased percentage of mouse red-cell rosette-forming cells. Under the technical condition used, peroxidase-positive monocytes were not shown to form such rosettes. However, if all the mouse red cell rosette-forming cells were shown to be of B nature, not all the B lymphocytes form rosettes with mouse erythrocytes and it is not unlikely that this marker could be characteristic for a subset of Ig-bearing B lymphocytes.

Animals↗
PubMed1976

Cytotoxic antibodies to human leukaemia cells in normal human sera.

Antibodies cytotoxic for human leukaemia cells were demonstrated in the serum of normal individuals: two of them being the fathers of leukaemia children, the third one being a normal unrelated donor. One of these sera (obtained from the father of an eight years old girl with acute myeloblastic leukaemia) appears to react widely with cells from acute leukaemias, both lymphoid and myeloid. On the other hand, the serum obtained from the normal blood donor appears to react almost exclusively with cells from acute lymphoblastic leukaemias, and more especially with those which do not form rosettes with sheep red cells.

Adult↗