Induction of eosinophilic colonies by interleukin-5 on acute myeloblastic leukaemic cells

Inflammatory response mediates cross-talk with immune function and reveals clinical features in acute myeloid leukemia

Accumulated genetic mutations are an important cause for the development of acute myeloid leukemia (AML), but abnormal changes in the inflammatory microenvironment also have regulatory effects on AML. Exploring the relationship between inflammatory response and pathological features of AML has implications for clinical diagnosis, treatment and prognosis evaluation. We analyzed the expression variation landscape of inflammatory response-related genes (IRRGs) and calculated an inflammatory response score for each sample using the gene set variation analysis (GSVA) algorithm. The differences in clinical- and immune-related characteristics between high- and low-inflammatory response groups were further analyzed. We found that most IRRGs were highly expressed in AML samples, and patients with high inflammatory response had poor prognosis and were accompanied with highly activated chemokine-, cytokine- and adhesion molecule-related signaling pathways, higher infiltration ratios of monocytes, neutrophils and M2 macrophages, high activity of type I/II interferon (IFN) response, and higher expression of immune checkpoints. We also used the Genomics of Drug Sensitivity in Cancer (GDSC) database to predict the sensitivity of AML samples with different inflammatory responses to common drugs, and found that AML samples with low inflammatory response were more sensitive to cytarabine, doxorubicin and midostaurin. SubMap algorithm also demonstrated that high-inflammatory response patients are more suitable for anti-PD-1 immunotherapy. Finally, we constructed a prognostic risk score model to predict the overall survival (OS) of AML patients. Patients with higher risk score had significantly shorter OS, which was confirmed in two validation cohorts. The analysis of inflammatory response patterns can help us better understand the differences in tumor microenvironment (TME) of AML patients, and guide clinical medication and prognosis prediction.

ncRNAs in Type-2 Immunity

Immunological diseases, including asthma, autoimmunity and immunodeficiencies, affect a growing percentage of the population with significant unmet medical needs. As we slowly untangle and better appreciate these complex genetic and environment-influenced diseases, new therapeutically targetable pathways are emerging. Non-coding RNA species, which regulate epigenetic, transcriptional and translational responses are critical regulators of immune cell development, differentiation and effector function, and may represent one such new class of therapeutic targets. In this review we focus on type-2 immune responses, orchestrated by T_H2 cell-derived cytokines, IL-4, IL-5 and IL-13, which stimulate a variety of immune and tissue responses- commonly referred to as type-2 immunity. Evolved to protect us from parasitic helminths, type-2 immune responses are observed in individuals with allergic diseases, including Asthma, atopic dermatitis and food allergy. A growing number of studies have identified the involvement of various RNA species, including microRNAs (miRNA) and long non-coding (lncRNA), in type-2 immune responses and in both clinical and pre-clinical disease settings. We highlight these recent findings, identify gaps in our understanding and provide a perspective on how our current understanding can be harnessed for novel treat opportunities to treat type-2 immune-mediated diseases.

CD4+ T helper 2 cells--microbial triggers, differentiation requirements and effector functions

Over the past 10 years we have made great strides in our understanding of T helper cell differentiation, expansion and effector functions. Within the context of T helper type 2 (Th2) cell development, novel innate-like cells with the capacity to secrete large amounts of interleukin-5 (IL-5), IL-13 and IL-9 as well as IL-4-producing and antigen-processing basophils have (re)-emerged onto the type 2 scene. To what extent these new players influence αβ+  CD4+  Th2 cell differentiation is discussed throughout this appraisal of the current literature. We highlight the unique features of Th2 cell development, highlighting the three necessary signals, T-cell receptor ligation, co-stimulation and cytokine receptor ligation. Finally, putting these into context, microbial and allergenic properties that trigger Th2 cell differentiation and how these influence Th2 effector function are discussed and questioned.

Recovery of drug sensitivity by MS-209, a new multidrug resistance-reversing agent, on acute myelogenous leukaemic blasts and K562 cells resistant to adriamycin cell line

The efficacy of MS-209, a quinoline derivative synthesized as a new multidrug resistance (MDR)-reversing agent, was studied on blast cells from 33 acute myelogenous leukaemia (AML) patients and on the human myelogenous leukaemia K562 cell line resistant to adriamycin (K562/ADM). By the addition of MS-209, the intracellular daunorubicin (DNR) contents which had been found to be low in P-gp-positive AML blasts and in K562/ADM were significantly enhanced to the level of P-gp-negative blasts and that of sensitive K562. The intracellular rhodamine (Rh123) contents also increased in P-gp-positive blasts and K562/ADM cells with MS-209. A leukaemic blast colony assay also demonstrated the effect of MS-209, i.e. a high D10 value for DNR of P-gp-positive blasts was reduced to the D10 level similar to that observed in P-gp-negative blasts by the addition of MS-209. The greater DNR sensitivity reversing effect of MS-209 was observed in blasts with higher P-gp positivity. These findings suggest the potential usefulness of MS-209 in overcoming MDR in AML patients, especially those with high P-gp expression. This study clarified the relationship between the clinical outcome of the patients and the P-gp positivity, intracellular DNR content and DNR drug sensitivity of leukaemic progenitors.

Hematopoietic Growth Factors and Blast Progenitors in Acute Leukemia

Leukemic cells are maintained by a minor subpopulation of cells called leukemic stem cells (LSC) with proliferative and self-renewal capacity, both of which are detected with leukemic colony assay, with the latter being an important prognositic factor. Drug sensitivity tests employing leukemic colony assay revealed the effects of cytotoxic drugs on LSC to be diverse and that cytosine arabinoside predominantly suppresses self-renewal, which probably accounts for its effectiveness in AML therapy. Hematopoietic growth factors (HGFs) regulate the growth of LSC and various in vitro effects of HGFs on acute leukemia cells have been reported. These effects appear to reflect physiological functions of each HGF and can be categorized into groups according to their distinct functions. Endogenously produced HGFs stimulate LSC in an autocrine or a paracrine fashion, resulting in autonomous growth of these cells, which also correlates with the patients' prognosis. HGFs can enhance the cytotoxicity of anti-leukemia drugs in vitro, possibly mainly through recruitment of LSC from the dormant state into active cell cycling. HGFs have been clinically tested in leukemia therapy. Although recovery of blood leukocyte counts can consistently be accelerated with HGF treatment, the effectiveness of HGFs in sensitizing leukemia cells to chemotherapeutic agents and/or improving patient prognosis has not been clearly demonstrated. Different strategies using HGFs and related molecules must be tested in future leukemia therapy.

Abolition of suppressive effect of acute myeloid leukemia cells on normal granulocyte-macrophage colony formation induced by interleukin-5 associated with eosinophilic cell induction

The effects of recombinant interleukin-5 (rIL-5) on leukemic blasts obtained from 22 acute myeloid leukemia (AML) patients were investigated. Recombinant IL-5 stimulated leukemic colony formation in the leukemic blasts of 50% of the patients (11/22), and in 7 of these 11 cell cultures leukemic eosinophilic colonies were induced. Eosinophilic cell induction was associated with cellular proliferation, that is, colony or cluster formation. Leukemic blasts cultured with rIL-5 and forming eosinophilic colonies no longer suppressed normal granulocyte-macrophage colony formation, suggesting that functional differentiation of these leukemic blasts took place. Induction of this type of functional differentiation of leukemic blasts may be of clinical value in promoting normal hematopoiesis.

Evidence for an abnormal profile of interleukin-4 (IL-4), IL-5, and gamma-interferon (gamma-IFN) in peripheral blood T cells from patients with allergic eosinophilic gastroenteritis

Allergic eosinophilic gastroenteritis is characterized by elevated total IgE, specific IgE to food antigens, and eosinophilia of tissue and blood. Because the lymphokines IL-4, IL-5, and gamma-interferon, regulate IgE synthesis, and eosinophilopoiesis in vitro, we examined whether there is an imbalance in their production in allergic eosinophilic gastroenteritis. To explore this hypothesis, three adult patients with allergic eosinophilic gastroenteritis were studied. Flow cytometric studies of peripheral blood mononuclear cells from these patients did not reveal evidence of T cell activation or disturbance of T cell numbers or subsets. T cells were capable of normal mitogenic activation in vitro. IL-4 and IL-5 production were markedly elevated with mitogenic stimulation. Most IL-4 and IL-5 production was by CD4+ T cells. Synthesis of IL-5 by CD4+ T lymphocytes in three patients and CD8+ T lymphocytes in two patients occurred in the absence of mitogen. Mitogen-stimulated GM-CSF and gamma-interferon synthesis by CD4+ T cells was normal. Lymphokine mRNA in total cellular RNA derived from endoscopic biopsies was examined by reverse transcription/polymerase chain reaction. Mucosal biopsies from control subjects and most biopsies from allergic eosinophilic gastroenteritis patients contained less than 10(-8) micrograms IL-5 mRNA/1 microgram total cellular mRNA. gamma-Interferon mRNA was not detected by reverse transcription/polymerase chain reaction in biopsies from patients with allergic eosinophilic gastroenteritis but was present in controls. These lymphokine abnormalities are consistent with the elevated IgE and eosinophilia seen in allergic eosinophilic gastroenteritis and suggest that strategies targeting T lymphocytes may be efficacious in treatment of this disease.

Correlation between the proliferative response to granulocyte colony-stimulating factor and the positivity of transferrin receptor in acute myeloblastic leukemia cells

The use of granulocyte colony-stimulating factor (G-CSF) after chemotherapy for acute myeloblastic leukemia (AML) has been reported. However, there is a drawback in that G-CSF may stimulate the proliferation of AML progenitors. To determine the parameter(s) indicative of responsiveness of AML blasts to G-CSF, various surface phenotypes of blasts were examined in relation to the blast colony formation stimulated by G-CSF in 39 AML patients. A correlation was found only with transferrin receptor positivity among the various phenotypes studied. The population mean of percentages of transferrin receptor-positive blasts in the group responding to G-CSF in vitro was significantly higher than that of blasts in the group not responding to G-CSF. A further correlation was found between transferrin receptor positivity and the number of G-CSF receptors on the blasts; that is, blasts expressing more G-CSF receptors have greater transferrin receptor positivity. In our previous study, we observed that blasts with a large number of G-CSF receptors produce more colonies in response to G-CSF. These results indicated that blasts expressing more transferrin receptors have a larger number of G-CSF receptors and may show more active proliferation in response to G-CSF. Therefore, the proliferative response of blasts to G-CSF can be predicted by examining transferrin receptor positivity. The clinical use of G-CSF in AML patients may be recommended when the patient's blasts have a low level of transferrin receptor expression. The measurement of transferrin receptors on blasts, instead of the rather complicated G-CSF receptor determination, would be a useful indicator for the safer application of G-CSF in AML patients.

Effects of interleukins 1-7 on the proliferation of T-lineage acute lymphoblastic leukemia cells

We investigated the proliferative effects of interleukins 1-7 (IL-1 to -7) on leukemic cells from 10 patients with T-lineage acute lymphoblastic leukemia (T-ALL). Five patients had CD7+4-8-acute leukemia, one had CD5+ acute leukemia, and four had CD1+ acute leukemia. To examine the proliferative effect of each interleukin, 3H-TdR incorporation method was used. In the presence of IL-1, no increase in 3H-TdR incorporation was observed for any of the T-ALL cells. With IL-2, 3H-TdR incorporation increased in cells from 5 out of 10 T-ALL patients, including those with CD7+4-8-, CD5+, and CD1+ acute leukemia. In the presence of IL-3 or IL-6, 3H-TdR incorporation increased in cells from 2 out of 5 patients with CD7+4-8- acute leukemia. However, CD5+ or CD1+ acute leukemia cells were not stimulated by IL-3 or IL-6. With IL-4, 3H-TdR incorporation was increased in the cells from 2 out of 5 patients with CD7+4-8- acute leukemia and in the cells of 2 of those with CD1+ acute leukemia. IL-5 increased the 3H-TdR incorporation by cells from 2 out of 5 patients with CD7+4-8- acute leukemia and 1 patient with CD1+ acute leukemia. IL-7 increased 3H-TdR incorporation in cells from all five CD7+4-8- acute leukemia and 2 of those with CD5+ or CD1+ leukemia. No synergistic effect was found when IL-7 and other cytokines were added to cells from the 3 patients with CD7+4-8- acute leukemia who were tested.