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Biomedical subjects

D Santoli

Publications and source records attributed to D Santoli.

At least 37 records · Page 2Linked to original sources
PubMed1995

Treatment of experimental glioblastoma with a human major histocompatibility complex nonrestricted cytotoxic T cell line.

This study investigates a new approach to adoptive therapy of glioblastoma using as antitumor effector a potent major histocompatibility complex nonrestricted killer clone (TALL-104) established from a patient with acute T-lymphoblastic leukemia. The human glioblastoma cell line U-87 MG could be successfully engrafted in mice with severe combined immunodeficiency using the i.p., intracerebral, and s.c. routes. The latter model was elected to evaluate therapy based on its high reproducibility. Tumor growth in mice engrafted s.c. was proportionally associated with splenomegaly and leukocytosis. Multiple transfers of lethally irradiated (non-proliferating) TALL-104 cells at the tumor site resulted in about 50-70% inhibition of tumor growth as compared to untreated mice, with concomitant reduction of splenomegaly and leukocytosis. The antitumor effects were inversely proportional to the size of the tumor at initiation of therapy, 90-100% inhibition occurring in severe combined immunodeficiency mice treated from the day of U-87 MG challenge. Neither splenomegaly nor leukocytosis developed in animals in which tumor growth was completely blocked. Stimulation of TALL-104 cells with either interleukin 2 or interleukin 12 prior to irradiation and adoptive transfer increased the antitumor efficacy of the killer cells to about the same extent. The potential usefulness of irradiated TALL-104 cells in adjuvant therapy against glioblastomas and other well-localized tumors is discussed.

Animals↗
PubMed1995

Effects of lethal irradiation and cyclosporin A treatment on the growth and tumoricidal activity of a T cell clone potentially useful in cancer therapy.

The TALL-104 cell line, originally derived from a patient with T cell leukemia, can be maintained indefinitely in culture in the presence of interleukin-2 (IL-2) and is endowed with a highly potent major-histocompatibility-complex (MHC)-non-restricted tumoricidal activity both in vitro and in animal models. The present study analyzes in detail the short- and long-term effects of irradiation and cyclosporin A (CsA) treatment on the growth and tumoricidal function of this T cell clone as compared to polyclonal lymphokine-activated killer (LAK) cell preparations from healthy donors. DNA and RNA syntheses by both TALL-104 and LAK cells were irreversibly arrested a few hours after irradiation with 40 Gy. However, 4-h 51Cr-release assays, performed on different days (day 1 to day 7) after irradiation, showed that the cytotoxic efficiency of TALL-104 cells against hematopoietic and solid tumor targets was only modestly reduced, whereas that of LAK cells was severely inhibited. Moreover, the cytotoxic responses to recombinant human IL-2 and IL-12, measured 18 h after irradiation and cytokine addition, were normal in the case of TALL-104 cells but were abolished in the case of LAK cells. Co-culture of IL-2- or IL-12-preactivated TALL-104 cells with a tumor target for 5 days in the absence of cytokines resulted in a lower efficiency of lysis, as compared to the non-irradiated effectors, especially if the initial stimulus was IL-12. These findings suggest the requirement of multiple cytokine stimulation for optimal expression of tumoricidal activity by lethally irradiated TALL-104 cells. CsA, while abrogating TALL-104 cell proliferation at the low dose of 0.5 microgram/ml, inhibited their cytotoxic function marginally only at high doses (100 micrograms/ml). By contrast, CsA reduced dose-dependently the cytotoxicity of LAK cells starting at very low doses (0.5 microgram/ml). CsA did not impair the ability of TALL-104 and LAK cells to produce interferon (IFN) gamma, tumor necrosis factor (TNF) alpha, and granulocyte/macrophage-colony-stimulatory factor (GM-CSF) in response to IL-2, IL-12, or tumor targets. Irradiation reduced drastically IFN gamma production by LAK, but not TALL-104 cells; release of TNF alpha and GM-CSF by either type of effector was inhibited by 10%-50%, depending on the stimulus. The high resistance and immunosuppressive drugs renders tis immortal T cell clone a potentially safe and effective reagent for new adoptive-transfer approaches to cancer in MHC-incompatible recipients.

Animals↗
PubMed1994

Effects of fatty acids on proliferation and activation of human synovial compartment lymphocytes.

The object of this study was to determine the effects of eicosanoid precursor fatty acids on activation and proliferation of T lymphocytes from synovial fluid and synovial tissue of rheumatoid arthritis patients. Proliferation was determined by direct cell counts; phenotypic characterization of surfaces molecules was by cytofluorometric analysis. Dihomogammalinolenic acid, arachidonic acid, and eicosapentaenoic acid suppressed proliferation of interleukin-2-dependent lymphocytes by as much as 80%; cell viability was not altered by fatty acids. Administration of particular fatty acids may prove to be a useful therapeutic intervention in rheumatoid arthritis patients because of their ability to suppress activation and proliferation of synovial compartment T lymphocytes.

Arthritis, Rheumatoid↗
PubMed1994

Reversal of acute myelogenous leukemia in humanized SCID mice using a novel adoptive transfer approach.

Advanced human malignancies cannot be permanently cured by adoptive transfer of autologous lymphokine-activated killer (LAK) cells. Moreover, administration of high doses of IL-2 to maintain LAK activity in vivo is associated with severe toxicity. In this study, we tested the anti-tumor efficacy of a uniquely potent MHC non-restricted human killer T cell clone (TALL-104) in humanized severe combined immunodeficient (SCID) mice bearing acute myelogenous leukemia (AML). We show that, in appropriate experimental conditions, TALL-104 cells could effectively reverse the aggressive growth of the myelomonocytic leukemia cell line U937 in SCID mouse tissues, leading to complete abrogation of AML. A single transfer of TALL-104 cells at the time of tumor challenge in combination with recombinant human (rh) IL-12 (1 microgram/d) prolonged significantly the life of the mice. However, eradication of leukemia, as monitored both clinically and by PCR, was achieved by repeated injection of the effectors at close intervals. Complete cure was obtained also upon transfer of lethally irradiated (non-proliferating) TALL-104 cells together with low doses of rh IL-2 (100 U/d). Most notably, of the mice that received multiple transfers of TALL-104 cells without cytokines in an advanced disease stage, 50% were clinically cured, and 50% survived significantly longer. The potential of TALL-104 cells as an effective and safe leukemia purging agent is discussed.

Animals↗
PubMed1993

Cellular and molecular mechanisms of activation of MHC nonrestricted cytotoxic cells by IL-12.

Freshly separated PBL and two IL-2-dependent clonal T cell lines (TALL-103/2 [TCR-gamma delta+] and TALL-104 [TCR-alpha beta+]) were used to dissect, at the cellular and molecular levels, the mechanisms governing the enhancing effects of IL-12 on MHC nonrestricted cytotoxic activity. IL-12 induced cytotoxicity both in PBL and TALL cells, although less efficiently than IL-2, and the two cytokines displayed additive effects. Unlike IL-2, IL-12 failed to enhance the CD3 or CD2 redirected killing of the TALL cell lines. Analysis of the percentage of E/T conjugates induced by these cytokines showed that IL-12 could increase PBL, but not TALL cell, binding only when used in combination with IL-2. This and the failure of IL-12 to increase the expression of several adhesion molecules on PBL and TALL cells indicated no significant role for IL-12 in the binding step of the lytic interaction. We also excluded that production of TNF-alpha, IFN-gamma, or IL-2 by the IL-12-activated effectors might account for the cytotoxicity-inducing effects of this cytokine. By contrast, IL-12 was found to induce cytotoxic granule formation in PBL and TALL cells and to up-regulate the expression of their cytolytic components, including perforin, serine esterases, and TIA-1, both at the protein and mRNA levels. The costimulatory action of IL-2 and IL-12 on granulogenesis and induction of cytolytic proteins correlated well with the additive effects on cytotoxicity. Studies with cyclohexamide and actinomycin D demonstrated that TALL cells but not PBL require de novo protein synthesis for expression of serine esterases and perforin mRNA after IL-2 and/or IL-12 stimulation, and that both cytokines act directly or indirectly at the transcriptional level. Overall, these data indicate that IL-12 acts mostly at a postbinding level of the lytic interaction, involving enhanced expression of cytotoxic mediators, and that IL-2 and IL-12 use partially distinct pathways to activate the MHC nonrestricted killer function of mature T cells and resting lymphocytes.

Cell Adhesion↗
PubMed1993

Establishment of a karyotypically normal cytotoxic leukemic T-cell line from a T-ALL sample engrafted in SCID mice.

Bone marrow (BM) cells from a child with an immature (CD3-) acute T lymphoblastic leukemia (T-ALL) bearing no chromosomal abnormalities failed to grow in long-term culture in the presence or absence of recombinant human (rh) growth factors but could be engrafted in severe combined immunodeficient (SCID) mice and induced leukemia. The leukemic cells recovered from the animal tissues could be adapted to grow in vitro in the presence of rh interleukin-2 (IL-2) and give rise to a growth factor-dependent cell line designated TALL-107. This cell line expresses T-cell-specific mature markers (CD2, CD3/T-cell receptor [TCR] alpha beta, CD8, CD56), and its growth can be inhibited by IL-4 of all the cytokines tested. Similar to the original leukemic blasts, TALL-107 cells are clonal, have rearranged TCR-beta, gamma, and delta loci, and a normal 46 XY karyotype. However, unlike the patient's BM cells, the TALL-107 cell line displays potent tumoricidal activity that is not major histocompatibility complex restricted. The magnitude of mRNA expression of perforin and serine esterases and of lytic activity depends on the doses of IL-2 added. TALL-107 cells can also be triggered by CD3- and CD2-specific monoclonal antibodies (MoAbs) to mediate reverse tumor cell lysis. In addition, this cell line produces high levels of interferon gamma and tumor necrosis factor alpha on stimulation with anti-CD3 and/or anti-CD2 MoAb both in the presence or absence of IL-2. The overall data indicate that the SCID mouse is able to support the functional maturation and expansion of a cytotoxic T-cell subset from some types of T-ALL.

Animals↗
PubMed1993

Effects of interleukin-11 on the proliferation and cell cycle status of myeloid leukemic cells.

Interleukin-11 (IL-11) is a pleiotropic cytokine with effects on many different targets. Within the hematopoietic system, the effects of IL-11 are largely manifest only through combination with other cytokines, including IL-3 and Steel factor (SF). In the present study, we addressed the question of IL-11 responsiveness within the different types of human leukemic cells, as well as the mechanism of action of IL-11 at the cellular level. Analysis of a panel of samples from different patients with acute myeloblastic leukemia (AML) and myeloid leukemic cell lines indicated that IL-11 alone was ineffective in supporting myeloid leukemic cell growth but frequently enhanced growth supported by IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), or SF. In contrast, three acute pre-B lymphocytic leukemia (pre-B-ALL) and two acute T lymphocytic leukemia (T-ALL) lines failed to respond to IL-11 alone or when combined with other cytokines. The growth enhancement of IL-11 among the AML patient samples was dose dependent and remarkably constant with half-efficient concentrations in the range of 0.3 to 0.4 ng/mL. The thymidine suicide studies with the patient samples revealed that 40% to 50% of the blast cells were in S-phase when exposed for 16 hours to IL-3 and this level was increased to 70% to 90% in response to either IL-11 or IL-6. Our data suggest that the latter two interleukins act synergistically with the direct mitogenic factor, IL-3, in triggering AML blast-cell proliferation. Detailed analysis with several patient samples further revealed that SF and IL-11 both enhance IL-3-supported clonogenic growth of AML blasts and the combination of all three growth factors yields optimal growth. In contrast, IL-6 does not further enhance the effect of IL-11. These results indicate that SF and IL-11 enhance IL-3-dependent clonogenic growth through two distinct pathways, whereas IL-6 and IL-11 may trigger the same pathway.

Cell Cycle↗
PubMed1993

Human stem cell factor (c-kit ligand) induces an autocrine loop of growth in a GM-CSF-dependent megakaryocytic leukemia cell line.

The M07e megakaryoblastic leukemia cell line is strictly dependent on either interleukin 3 (IL-3) or granulocyte-macrophage colony-stimulating factor (GM-CSF) for continuous growth. This study shows that recombinant human stem-cell factor (rhSCF) can completely replace these lymphokines in supporting the continued propagation of M07e cells mostly by eliciting GM-CSF secretion in this target. In fact, in short-term proliferation assays the stimulatory activity of SCF is blocked about 75% by a GM-CSF-specific serum. In addition, we could detect GM-CSF expression by SCF-stimulated M07e cells, both at the protein and mRNA levels. In contrast, SCF does not induce transcripts for any other cytokine to which M07e cells are responsive, including IL-2, IL-3, IL-4, and IL-6. Overall, these data show that the ability of SCF to support the growth of this megakaryocytic cell line is mediated mostly by the induction of an autocrine loop of activation involving GM-CSF production. The finding that SCF can stimulate GM-CSF secretion also in an IL-2-dependent T-lymphoblastic leukemia cell line indicates that SCF can act on cells of both myeloid and lymphoid lineages, and that the ability to induce cytokines in target cells represents an important aspect of its mechanism of action.

Cell Division↗
PubMed1993

Cytokine modulation of the susceptibility of acute T-lymphoblastic leukemia cell lines to LAK activity.

We studied the regulatory effects of various cytokines on the susceptibility to lymphocyte-mediated lysis of cell lines established from patients with acute T-lymphoblastic leukemia (T-ALL). None of the cytokines tested affected the sensitivity of these targets to natural killer activity. In contrast, specific cytokines, different for each cell line, enhanced the susceptibility to lymphokine-activated killer (LAK) cells, while interferon gamma (IFN)-gamma always induced resistance. The same cytokines that increased LAK susceptibility also induced proliferative responses. The TALL-101 cell line, which responded to granulocyte-macrophage colony-stimulating factor (GM-CSF) with increased susceptibility to lysis, and to IFN-gamma with resistance, was used as a model to analyze the mechanisms underlying these changes. Cold target inhibition and conjugate formation assays both indicated that the changes in LAK susceptibility were not at the level of effector-target (E/T) binding. Furthermore, no significant changes in surface expression of adhesion molecules involved in E/T binding were induced by either GM-CSF or IFN-gamma on TALL-101 cells. Finally, N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl-esterase assays demonstrated no differences in the ability of these cytokines to trigger the secretion of cytolysins in the bound effectors compared to unstimulated cells. Taken together, these results suggest that the cytokine-modulated susceptibility to lysis of these T-ALL lines might occur at a post-binding stage with mechanisms involving an altered responsiveness to lytic factors.

Cell Division↗
PubMed1992

Natural killer (NK) cell stimulatory factor or IL-12 has differential effects on the proliferation of TCR-alpha beta+, TCR-gamma delta+ T lymphocytes, and NK cells.

We have analyzed the effects of NK cell stimulatory factor/IL-12, on proliferation of PBL and their subsets. IL-12 synergizes with lectins and phorbol diesters to induce proliferation of CD4+ and CD8+ peripheral blood T lymphocytes. In the case of phorbol-diester-induced proliferation, the effect of IL-12 is in part mediated by induced IL-2 production, as suggested by the observation that IL-12 enhances IL-2 production in these cultures and that anti-IL-2 antibodies inhibit proliferation. IL-12 synergizes also with anti-CD3 antibodies and with allogeneic stimulation in MLC in inducing T cell proliferation. IL-12 alone is mitogenic for preactivated T and NK lymphoblasts. This mitogenic effect is observed with similar doses of IL-12 on NK lymphoblasts as well as on CD4+ and CD8+ TCR-alpha beta+ and on TCR-gamma delta+ lymphoblasts. On TCR-alpha beta+ T lymphocytes the effect of IL-12 is always additive to that of IL-2 over a wide dose range. The same effect is observed on highly activated, actively proliferating NK cells. However, on NK and TCR-gamma delta+ lymphoblasts reverting to a resting state after stimulation and on a TCR-gamma delta+ acute leukemia-derived T cell line, IL-12 inhibits significantly the proliferation induced by moderate to high doses (10 to 100 U/ml) of IL-2. This inhibitory effect is, at least in part, indirect, and depends on IL-12-induced production of TNF. Neutralizing anti-TNF antibodies, but not anti-IFN-gamma and anti-transforming growth factor antibodies, restore by more than 70% the inhibition of proliferation induced by IL-12 in these cultures. However, TNF alone cannot mimic the inhibitory effect of IL-12 on the IL-2-induced proliferation of NK and TCR-gamma delta+ lymphoblasts, suggesting the involvement of additional mechanisms. The relevance of these findings for the biology of lymphocyte subsets mediating MHC nonrestricted cytotoxicity is discussed.

Flow Cytometry↗
PubMed1992

Phenotypic changes induced by interleukin-2 (IL-2) and IL-3 in an immature T-lymphocytic leukemia are associated with regulated expression of IL-2 receptor beta chain and of protein tyrosine kinases LCK and LYN.

We have previously reported the establishment of an interleukin-3 (IL-3)-dependent and phenotypically myeloid cell line (TALL-103/3), obtained by culturing cells from an immature T-lymphoblastic leukemia in the presence of IL-3. These cells differentiated into a T-lymphoid cell line (TALL-103/2) upon removal of IL-3 and incubation in IL-2. Despite the different phenotype, the two cell lines remained karyotypically and genotypically identical. Here, we have analyzed the phenotypic changes and the signaling events induced by these two lymphokines in TALL-103/3 cells by switching them to temporary growth in IL-2 and returning them to IL-3. All four sublines obtained (the myeloid in IL-3 and the lymphoid in IL-2) expressed RNA for CD3, IL-2 receptor (R) alpha, and T-cell receptor (TCR)-gamma and -delta chains. However, cells cultured in IL-3 failed to express detectable levels of the IL-2R beta chain at both the protein and RNA levels, whereas cells exposed to IL-2 always expressed IL-2R beta. In parallel with the changes in IL-2R beta expression, the SRC-like protein tyrosine kinase (PTK) p56 LCK could not be detected in IL-3-dependent cells, but was abundant in the IL-2-dependent cells and underwent markedly increased autophosphorylation in response to IL-2. In contrast, p53/p56 LYN was highly expressed in IL-3-dependent cells, and greatly decreased when these cells were switched to growth in IL-2. LYN kinase autophosphorylation modestly increased in response to IL-3. None of the other kinases in the SRC family that were tested underwent increased autophosphorylation after lymphokine stimulation, indicating the specificity of IL-2 for LCK and of IL-3 for LYN. The TALL-103 cell lines provide a unique system to study the interaction between lymphokines and SRC-family PTKs in signal transduction pathways leading to hematopoietic cell differentiation.

Cell Division↗
PubMed1992

Interleukin-3 regulates the activity of the LYN protein-tyrosine kinase in myeloid-committed leukemic cell lines.

The lymphokine interleukin-3 (IL-3) promotes the growth and survival of immature hematopoietic cells. Previous studies have shown that IL-3 induces rapid increases in protein-tyrosine kinase (PTK) activity in IL-3--dependent cells. Unlike some other hematopoietic growth factor receptors (eg, c-fms and c-kit), however, the known subunits of the IL-3 receptor (IL-3R) lack intrinsic kinase activity. Recently, it was reported that the IL-2R (whose p75 beta-subunit shares sequence homology with a known murine IL-3R subunit and a common beta-subunit of the human IL-3R and granulocyte-macrophage colony-stimulating factor [GM-CSF] receptors) can physically associate with and regulate the activity of the SRC-family PTK, p56-LCK. Because most IL-3--dependent cells contain p53/56-LYN, but not p56-LCK, we explored the effects of IL-3 on the activities of LYN and other SRC-like PTKs in two human leukemic cell lines, AML-193 and TALL-101, which are phenotypically myeloid, and whose in vitro growth is dependent on IL-3. These cells expressed four of the eight known SRC-family proto-oncogenes: lyn, fyn, yes, and hck. When these factor-dependent leukemic cell lines were deprived of lymphokine to achieve cellular quiescence and then restimulated with IL-3, rapid increases (detectable within 1 minute and maximal by 10 minutes) were observed in the activity of the p53/56-LYN kinase, as assessed by in vitro kinase assays. In contrast, no alteration in the activities of other SRC-family PTKs present in these cells was detected after restimulation with IL-3 under the same conditions. This effect of IL-3 reflected an increase in the specific activity of the LYN kinase, because levels of the 53-Kd and 56-Kd LYN proteins were unaltered by IL-3 stimulation, as assessed by immunoblotting. Furthermore, the magnitude of these inducible increases in LYN kinase activity was dependent on the concentration of IL-3, and correlated with IL-3--induced proliferation. The IL-3--induced upregulation of LYN kinase activity may be mediated by the 120-Kd common subunit of the human IL-3 and GM-CSF receptors, because GM-CSF also stimulated marked increases in the activity of the LYN kinase, whereas granulocyte-CSF (G-CSF) did not, despite inducing cellular proliferation. These observations provide the first example of an IL-3--regulable PTK, and strongly suggest that the p53/56-LYN kinase participates in early IL-3--initiated signalling events, at least in some human leukemic cell lines.

Cell Line↗
PubMed1992

Mechanisms of IFN-gamma induction by natural killer cell stimulatory factor (NKSF/IL-12). Role of transcription and mRNA stability in the synergistic interaction between NKSF and IL-2.

We have investigated the molecular mechanisms regulating IFN-gamma production in human T lymphocytes stimulated by NK cell stimulatory factor (NKSF/IL-12). We show that NKSF synergizes with IL-2 and phorbol diesters inducing the accumulation of IFN-gamma mRNA in PHA-activated T cell blasts. NKSF regulates IFN-gamma mRNA expression in PHA blasts and the T leukemia cell line, TALL-103/2, at both the transcriptional and posttranscriptional levels. NKSF increases the transcriptional rate for IFN-gamma in both these cell types, as determined by nuclear run-on analysis. However, synergy between NKSF and IL-2 can be demonstrated only at the level of mRNA stability, and both cytokines are required to increase IFN-gamma mRNA half-life.

Blotting, Northern↗
PubMed1992

Interleukin 4 inhibits IL-2-induced proliferation of a human T-leukemia cell line without interfering with p56-LCK kinase activation.

Recently we described the establishment in culture and the immunophenotypic and functional characteristics of a human T-leukemia line TALL-103/2 derived from the T-cell receptor (TCR)-gamma/delta subset of T-lymphocytes. TALL-103/2 cells are absolutely dependent on interleukin 2 (IL-2) for their growth and survival in culture and thus provide a model cell line for studies of IL-2 signal transduction in a TCR-gamma/delta T-cell. In this report, we focus on the regulation of SRC-family protein tyrosine kinases (PTKs) by IL-2. TALL-103/2 cells were found to contain p56-LCK, p59-FYN, p62-YES and p53/56-LYN. Stimulation of growth factor-deprived TALL-103/2 cells with IL-2, however, induced increases in the relative activity only of the p56-LCK kinase. This IL-2-mediated increase in LCK kinase activity was manifested both by increased kinase autophosphorylation and by increased phosphorylation of the exogenous substrate enolase during in vitro kinase assays. Furthermore, immunoblot assays determined that the levels of p56-LCK protein were unaltered by IL-2-treatment, indicating that the measured elevations in LCK kinase activity reflected an increase in the specific activity of this PTK. In TALL-103/2 cells, IL-2 stimulated concentration-dependent increases in p56-LCK activity that displayed rapid and transient kinetics: detectable increases occurred within 1 minute after IL-2 stimulation, peaked at 10 minutes, and declined to baseline levels by 30 minutes. Treatment of TALL-103/2 cells with IL-4 abrogated IL-2-initiated proliferation, but did not inhibit IL-2-mediated activation of p56-LCK.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-Response Relationship, Drug↗
PubMed1992

Pediatric leukemia/lymphoma with t(8;14)(q24;q11).

A variety of chromosomal translocations occur in pediatric T-cell acute lymphoblastic leukemia (T-ALL) in which a cellular oncogene or growth-related gene is translocated to the alpha/delta locus of the T-cell receptor gene. The t(8;14)(q24;q11) has been described at the cytogenetic and molecular level, but the disease associated with this translocation has not been defined clinically. Fifteen pediatric cases of leukemia/lymphoma with a t(8;14)(q24;q11) chromosomal translocation were collected from previous publications and institutional records. The estimated prevalence of this abnormality among all cases of ALL was 1%. The t(8;14)(q24;q11) disease was characterized by male predominance (10/15), a median age of 5.5 years (range 1.8-17 years), high white blood cell count (median 95 x 10(9)/l), central nervous system infiltration (4/11), bulky extramedullary leukemia (10/11), and T-cell immunophenotype (12/15). The median event-free survival was 4 months, and the median survival, 11 months. Seven cell lines with t(8;14)(q24;q11) were established from six of the cases; four were T-lymphoblastic, one was T-lymphoblastic, but expressed myeloid-related antigens, and two were predominantly myeloid. t(8;14)(q24;q11) leukemia/lymphoma and other ALLs involving 13(q11) have in common a high tumor burden, early spread to extramedullary sites, a propensity to form T-lymphoblastic or T-myeloid cell lines and, usually, an aggressive clinical course.

Adolescent↗
PubMed1992

The severe combined immunodeficient (SCID) mouse as a model for human myeloid leukemias.

Recent work has demonstrated the ability of lymphoblastic leukemias of pre-B- and T-cell origin to grow in severe combined immunodeficient (SCID) mice with a pattern reminiscent of the human clinical disease. Here, we investigated the possibility of engrafting human myeloid leukemias using both established cell lines and primary patient material. Whereas the two growth factor-independent cell lines K562 and U937 grew aggressively and induced leukemia in these animals, three other myeloid cell lines which require interleukin 3 or granulocyte-macrophage colony-stimulating factor for continuous growth in vitro failed to induce disease. Primary bone marrow and peripheral blood cells from five out of seven patients with different types of myeloid leukemias (undifferentiated, megakaryoblastic, monoblastic and chronic myelogenous leukemia in blast crisis) induced patterns of leukemic infiltration that were distinct for each leukemia subtype. The diagnosis of leukemia in SCID mice was established by microscopic detection of myeloblasts in the bone marrow, peripheral blood and, in some instances, in extramedullary sites, including the central nervous system and gonads. The karyotype and phenotype of the blasts recovered from mouse tissues were identical to those of the original patient cells. Moreover, human specific ALU sequences were amplified from the bone marrow DNA by polymerase chain reaction. Despite their ability to grow in vivo by serial transfers in SCID mice, the leukemic cells recovered from mouse tissues could not be maintained in vitro, even in the presence of recombinant cytokines. Overall, these data indicate that the SCID mouse may represent a useful animal model for human myeloid leukemias and for the development of new pharmacological and molecular approaches to therapy.

Adult↗
PubMed1992

Regulation of SRC-family protein tyrosine kinases by interleukins, IL-2, and IL-3.

Unlike many other growth factor receptors, the known subunits of the receptors for the Interleukins IL-2 and IL-3 lack intrinsic tyrosine kinase activity, and yet increases in the phosphorylation of proteins on tyrosines is a rapid event in hematolymphoid cells following stimulation with these lymphokines. Here we show that IL-2 and IL-3 regulate the activity of specific members of the SRC-family of non-receptor protein tyrosine kinases (PTKs). In IL-2-dependent T-cell lines, IL-2 induced rapid and transient increases in the activity of the p56-LCK kinase without influencing the activities of other SRC-like PTKs (p59-FYN, p62-YES) in these T-lymphocytes. In contrast to IL-2's effects on p56-LCK in T-cells, studies of an IL-2-responsive cell line of the B-cell lineage that lacks p56-LCK revealed that IL-2 specifically regulates the activity of the p53/56-LYN kinase. Thus, some flexibility exists in the ability of various SRC-like PTKs to functionally couple to IL-2 signalling pathways. In several IL-3-dependent myeloid-committed leukemic cell lines, IL-3 was found to specifically regulate the activity of the p53/56-LYN kinase without affecting the activities of other SRC-like PTKs (p59/64-HCK, p59-FYN, p62-YES) in these hematopoietic cells. This finding that p53/56-LYN can be regulated by both IL-2 in B-lineage cells and IL-3 in myeloid-committed cells demonstrates that the same SRC-family PTK can participate in signal transduction events mediated via two independent receptor systems. Taken together, our findings imply that the specific combinations of lymphokine receptors and SRC-like PTKs available for coupling with those receptors are coordinately controlled during the differentiation of hematopoietic cells.

Animals↗