The imbalanced profile and clinical significance of T helper associated cytokines in bone marrow microenvironment of the patients with acute myeloid leukemia

Investigating the biology of microRNA links to ALDH1A1 reveals candidates for preclinical testing in acute myeloid leukemia

Aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is a member of the aldehyde dehydrogenase gene subfamily that encode enzymes with the ability to oxidize retinaldehyde. It was recently shown that high ALDH1A1 RNA abundance correlates with a poor prognosis in acute myeloid leukemia (AML). AML is a hematopoietic malignancy associated with high morbidity and mortality rates. Although there are a number of agents that inhibit ALDH activity, it would be crucial to develop methodologies for adjustable genetic interference, which would permit interventions on several oncogenic pathways in parallel. Intervention in multiple oncogenic pathways is theoretically possible with microRNAs (miRNAs or miRs), a class of small non‑coding RNAs that have emerged as key regulators of gene expression in AML. A number of miRNAs have shown the ability to interfere with ALDH1A1 gene expression directly in solid tumor cells, and these miRNAs can be evaluated in AML model systems. There are indications that a few of these miRNAs actually do have an association with AML disease course, rendering them a promising target for genetic intervention in AML cells.

Inflammation and Related Signaling Pathways in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy, and inflammatory signaling is involved in its pathogenesis. Cytokines exert a robust effect on the progression of AML and affect survival outcomes. The dysregulation in the cytokine network may foster a pro-tumorigenic microenvironment, increasing leukemic cell proliferation, decreasing survival and driving drug resistance. The dominance of pro-inflammatory mediators such as IL-11β, TNF-α and IL-6 over anti-inflammatory mediators such as TGF-β and IL-10 has been implicated in tumor progression. Additionally, inflammatory cytokines have favored certain populations of hematopoietic stem and progenitor cells with mutated clonal hematopoiesis genes. This article summarizes current knowledge about inflammatory cytokines and signaling pathways in AML, their modes of action and the implications for immune tolerance and clonal hematopoiesis, with the aim of finding potential therapeutic interventions to improve clinical outcomes in AML patients.

Clinical significance of T helper cell subsets in the peripheral blood and bone marrow of patients with multiple myeloma

Background

T helper (Th) cell subsets primarily assist B cells in differentiating into plasma cells in the germinal center. The mechanism of malignant transformation of plasma cells is an important target for the clinical treatment of MM; however, the mechanism remains unclear.

Methods

We collected the peripheral blood (PB) and bone marrow (BM) samples of 33 patients with MM. In addition, the PB was also collected from 25 normal healthy controls (HCs). We analyzed the percentages of Th cell subsets in the PB and BM samples of patients with MM.

Results

Tfh/CD4+ were positively correlated with the proportion of myeloma cells in the BM and PB samples (r = 0.592, P = 0.002 and r = 0.510, P = 0.010 respectively), and showed a strong correlation between the BM and PB samples (r = 0.6559, P = 0.0095). In the PB samples, the percentages of Th2/CD4+ and Tfh2/Tfh cells were significantly lower in patients with MM than in HCs (P = 0.00013 and P = 0.0004, respectively), whereas the percentage of Th17/CD4+ and Tfh17/Tfh was significantly higher in newly diagnosed patients with MM than in HCs (P = 0.0037 and P = 0.03, respectively), and all these cells showed a good predictive value for MM (area under the curve [AUC] 0.781, = 0.792, = 0.837, and 0.723 respectively). In the PB samples, all subsets of PD-1+ICOS- Tfh showed a noticeable downward trend in MM from newly diagnosed to non-remission and remission groups. In contrast, all subsets of PD-1-ICOS+ Tfh increased gradually.

Conclusion

Th cell subsets play an important role in the occurrence and development of MM and may provide a fundamental basis for identifying new immunotherapy targets and prognosis.

The role of IL-22 in cancer

Interleukin-22, discovered in the year of 2000, is a pleiotropic Th17 cytokine from the IL-10 family of cytokines. IL-22 signals through the type 2 cytokine receptor complex IL-22R and predominantly activates STAT3. This pathway leads to the transcription of several different types of genes, giving IL-22 context-specific functions ranging from inducing antimicrobial peptide expression to target cell proliferation. In recent years, it has been shown that IL-22 is involved in the pathogenesis of neoplasia in some cancers through its pro-proliferative and anti-apoptotic effects. This review highlights studies with recent discoveries and conclusions drawn on IL-22 and its involvement and function in various cancers. Such a study may be helpful to better understand the role of IL-22 in cancer so that new treatment could be developed targeting IL-22.

Higher PD-1/Tim-3 expression on IFN-γ+ T cells is associated with poor prognosis in patients with acute myeloid leukemia

With the success of immune checkpoint inhibitors (ICI), such as anti- programmed death-1 (PD-1) antibody for solid tumors and lymphoma immunotherapy, a number of clinical trials with ICIs have been attempted for acute myeloid leukemia (AML) immunotherapy; however, limited clinical efficacy has been reported. This may be due to the heterogeneity of immune microenvironments and various degrees of T cell exhaustion in patients and may be involved in the IFN-γ pathway. In this study, we first characterized the percentage of PD-1+ and T cell immunoglobulin mucin-domain-containing-3 (Tim-3) +IFN-γ+ T cells in peripheral blood (PB) in AML compared with healthy individuals (HIs) by flow cytometry and further discussed the possibility of the reversal of T cell exhaustion to restore the secretion capacity of cytokines in T cells in AML based on blockade of PD-1 or Tim-3 (anti-PD-1 and anti-Tim-3 antibody) in vitro using a cytokine protein chip. A significantly increased percentage of PD-1+, Tim-3+, and PD-1+Tim-3+ IFN-γ+ T cells was observed in PB from patients with AML in comparison with HIs. Moreover, higher PD-1+IFN-γ+CD3+/CD8+ T cell levels were associated with poor overall survival in AML patients. Regarding leukemia cells, the percentage of Tim-3 in CD117+CD34+ AML cells was positively correlated with PD-1 in IFN-γ+CD4+ T cells. Furthermore, blocking PD-1 and Tim-3 may involve multiple cytokines and helper T cell subsets, mainly Th1 and Treg cells. Blockade of PD-1 or Tim-3 tends to restore cytokine secretion to a certain extent, a synergistic effect shown by the co-blockade of PD-1 and Tim-3. However, we also demonstrated the heterogeneity of secretory cytokines in ICI-treated T cells in AML patients.

Cytokine levels in patients with non-M3 myeloid leukemia are key indicators of how well the disease responds to chemotherapy

Acute myeloid leukemia (AML) is a malignant hematological neoplastic disease. Autocrine or paracrine cytokines released by leukemic cells regulate the proliferation of AML cells. It is uncertain whether cytokines can indicate whether patients with AML are in remission with chemotherapy. The goal of this study was to evaluate the levels of Th1/Th2/Th17 cytokines in AML patients before and after chemotherapy to determine whether the cytokine levels could predict disease remission after chemotherapy. It was found that the levels of IL-5, IL-6, IL-8, IL-10, TNF-α, TNF-β, IL-17F, and IL-22 were significantly increased at the time of AML diagnosis in patients who achieved remission after two chemotherapy treatments (P < 0.05). After chemotherapy, the cytokine levels were reduced in patients with remission, while the levels of IL-6 and IL-8 were raised in patients without remission (P < 0.05). A comparison of cytokine levels before and after chemotherapy in patients who achieved remission showed areas under the curve (AUCs) of 0.69 for both IL-6 and IL-8. In addition, a comparison of the remission and non-remission groups after chemotherapy showed an AUC of 0.77 for IL-6. We then calculated the cutoff value using receiver operating characteristic curves. Values of IL-6 < 9.99 and IL-8 < 8.46 at the time of diagnosis were predictive of chemotherapy success and remission, while IL-6 > 14.89 at diagnosis suggested that chemotherapy would not be successful and remission would not be achieved. Multifactorial analysis showed that age, Neu, IL-6, and IL-8 were independent risk factors for AML prognosis, and IL-6 (OR = 5.48, P = 0.0038) was superior to age (OR = 3.36, P = 0.0379), Neu (OR = 0.28, P = 0.0308), IL-8 (OR = 0.0421, P = 0.0421). In conclusion, IL-6 levels were found to be predictive of the likelihood of remission.

Fabrication of a three-dimensional bone marrow niche-like acute myeloid Leukemia disease model by an automated and controlled process using a robotic multicellular bioprinting system

BACKGROUND

Acute myeloid leukemia (AML) is a hematological malignancy that remains a therapeutic challenge due to the high incidence of disease relapse. To better understand resistance mechanisms and identify novel therapies, robust preclinical models mimicking the bone marrow (BM) microenvironment are needed. This study aimed to achieve an automated fabrication process of a three-dimensional (3D) AML disease model that recapitulates the 3D spatial structure of the BM microenvironment and applies to drug screening and investigational studies.

METHODS

To build this model, we investigated a unique class of tetramer peptides with an innate ability to self-assemble into stable hydrogel. An automated robotic bioprinting process was established to fabricate a 3D BM (niche-like) multicellular AML disease model comprised of leukemia cells and the BM's stromal and endothelial cellular fractions. In addition, monoculture and dual-culture models were also fabricated. Leukemia cell compatibility, functionalities (in vitro and in vivo), and drug assessment studies using our model were performed. In addition, RNAseq and gene expression analysis using TaqMan arrays were also performed on 3D cultured stromal cells and primary leukemia cells.

RESULTS

The selected peptide hydrogel formed a highly porous network of nanofibers with mechanical properties similar to the BM extracellular matrix. The robotic bioprinter and the novel quadruple coaxial nozzle enabled the automated fabrication of a 3D BM niche-like AML disease model with controlled deposition of multiple cell types into the model. This model supported the viability and growth of primary leukemic, endothelial, and stromal cells and recapitulated cell-cell and cell-ECM interactions. In addition, AML cells in our model possessed quiescent characteristics with improved chemoresistance attributes, resembling more the native conditions as indicated by our in vivo results. Moreover, the whole transcriptome data demonstrated the effect of 3D culture on enhancing BM niche cell characteristics. We identified molecular pathways upregulated in AML cells in our 3D model that might contribute to AML drug resistance and disease relapse.

CONCLUSIONS

Our results demonstrate the importance of developing 3D biomimicry models that closely recapitulate the in vivo conditions to gain deeper insights into drug resistance mechanisms and novel therapy development. These models can also improve personalized medicine by testing patient-specific treatments.

A dual-role for IL-10: From leukemogenesis to the tumor progression in acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer in the world, and accounts for 25% of all childhood cancers among children under 15 years of age. Longitudinal studies have shown that children with ALL are born with a deregulated immune response that, together with postnatal environmental exposures, favor the onset of the disease. In this context, IL-10, a key cytokine in the regulation of the immune response, presents itself as a paradoxical mediator, initially influencing the development of ALL through the regulation of inflammatory processes and later on the progression of malignancy, with the increase of this molecule in the leukemia microenvironment. According to the literature, this cytokine plays a critical role in the natural history of the disease and plays an important role in two different though complex scenarios. Thus, in this review, we explore the dual role of IL-10 in ALL, and describe its biological characteristics, immunological mechanisms and genetics, as well as its impact on the leukemia microenvironment and its clinical implications.

Modulation of bone marrow and peripheral blood cytokine levels by age and clonal hematopoiesis in healthy individuals

Aging is associated with bone marrow (BM) inflammaging and, in some individuals, with the onset of clonal hematopoiesis (CH) of indeterminate potential. In this study conducted on 94 strictly healthy volunteers (18 to 80 yo), we measured BM and peripheral blood (PB) plasma levels of 49 hematopoietic and inflammatory cytokines. With aging, 7 cytokines increased in BM (FLT3L, CXCL9, HGF, FGF-2, CCL27, IL-16, IL-18) and 8 decreased (G-CSF, TNF, IL-2, IL-15, IL-17A, CCL7, IL-4, IL-10). In PB, 10 cytokines increased with age (CXCL9, FLT3L, CCL27, CXCL10, HGF, CCL11, IL-16, IL-6, IL-1 beta, CCL2). CH was associated with higher BM levels of MIF and IL-1 beta, lower BM levels of IL-9 and IL-5 and higher PB levels of IL-15, VEGF-A, IL-2, CXCL8, CXCL1 and G-CSF. These reference values provide a useful tool to investigate anomalies related to inflammaging and potentially leading to the onset of age-related myeloid malignancies or inflammatory conditions.

The cytokine network in acute myeloid leukemia

Acute myeloid leukemia (AML) is a highly heterogeneous malignancy of the blood and bone marrow, characterized by clonal expansion of myeloid stem and progenitor cells and rapid disease progression. Chemotherapy has been the first-line treatment for AML for more than 30 years. Application of recent high-throughput next-generation sequencing technologies has revealed significant molecular heterogeneity to AML, which in turn has motivated efforts to develop new, targeted therapies. However, due to the high complexity of this disease, including multiple driver mutations and the coexistence of multiple competing tumorigenic clones, the successful incorporation of these new agents into clinical practice remains challenging. These continuing difficulties call for the identification of innovative therapeutic approaches that are effective for a larger cohort of AML patients. Recent studies suggest that chronic immune stimulation and aberrant cytokine signaling act as triggers for AML initiation and progression, facets of the disease which might be exploited as promising targets in AML treatment. However, despite the greater appreciation of cytokine profiles in AML, the exact functions of cytokines in AML pathogenesis are not fully understood. Therefore, unravelling the molecular basis of the complex cytokine networks in AML is a prerequisite to develop new therapeutic alternatives based on targeting cytokines and their receptors.

Chronic IL-15 Stimulation and Impaired mTOR Signaling and Metabolism in Natural Killer Cells During Acute Myeloid Leukemia

Natural Killer (NK) cells are potent anti-leukemic immune effectors. However, they display multiple defects in acute myeloid leukemia (AML) patients leading to reduced anti-tumor potential. Our limited understanding of the mechanisms underlying these defects hampers the development of strategies to restore NK cell potential. Here, we have used a mouse model of AML to gain insight into these mechanisms. We found that leukemia progression resulted in NK cell maturation defects and functional alterations. Next, we assessed NK cell cytokine signaling governing their behavior. We showed that NK cells from leukemic mice exhibit constitutive IL-15/mTOR signaling and type I IFN signaling. However, these cells failed to respond to IL-15 stimulation in vitro as illustrated by reduced activation of the mTOR pathway. Moreover, our data suggest that mTOR-mediated metabolic responses were reduced in NK cells from AML-bearing mice. Noteworthy, the reduction of mTOR-mediated activation of NK cells during AML development partially rescued NK cell metabolic and functional defects. Altogether, our data strongly suggest that NK cells from leukemic mice are metabolically and functionally exhausted as a result of a chronic cytokine activation, at least partially IL-15/mTOR signaling. NK cells from AML patients also displayed reduced IL-2/15Rβ expression and showed cues of reduced metabolic response to IL-15 stimulation in vitro, suggesting that a similar mechanism might occur in AML patients. Our study pinpoints the dysregulation of cytokine stimulation pathways as a new mechanism leading to NK cell defects in AML.

Bone Marrow Soluble Immunological Mediators as Clinical Prognosis Biomarkers in B-Cell Acute Lymphoblastic Leukemia Patients Undergoing Induction Therapy

Different factors are used as predictors of unfavorable clinical outcomes in B-Cell Acute Lymphoblastic Leukemia (B-ALL) patients. However, new prognostic markers are needed in order to allow treatment to be more accurate, providing better results and an improved quality of life. In the present study, we have characterized the profile of bone marrow soluble mediators as possible biomarkers for risk group stratification and minimal residual disease (MRD) detection during induction therapy. The study featured 47 newly-diagnosed B-cell acute lymphoblastic leukemia (B-ALL) patients that were categorized into subgroups during induction therapy according to risk stratification at day 15 [Low Risk (LR), Low Risk increasing to High Risk (LR→HR) and High Risk (HR)] and the MRD detection on day 35 (MRD^(-) and MRD⁽⁺⁾). Soluble immunological mediators (CXCL8, CCL2, CXCL9, CCL5, CXCL10, IL-1β, IL-6, TNF, IFN-γ, IL-17A, IL-4, IL-5, IL-10 and IL-2) were quantified by cytometric bead array and ELISA. Our findings demonstrated that increased levels of CCL5, IFN-γ and IL-2 at baseline appeared as putative candidates of good prognosis in LR and MRD^(-) subgroups, while CCL2 was identified as a consistent late biomarker associated with poor prognosis, which was observed on D35 in HR and MRD⁽⁺⁾ subgroups. Furthermore, apparently controversial data regarding IL-17A and TNF did not allow the definition of these molecules as either positive or negative biomarkers. These results contribute to the search for novel prognostic indicators, and indicate the potential of bone marrow soluble mediators in prognosis and follow-up of B-ALL patients during induction therapy.

Imbalance of Chemokines and Cytokines in the Bone Marrow Microenvironment of Children with B-Cell Acute Lymphoblastic Leukemia

In the hematopoietic microenvironment, leukemic cells secrete factors that imbalanced chemokine and cytokine production. However, the network of soluble immunological molecules in the bone marrow microenvironment of acute lymphoblastic leukemia (ALL) remains underexplored. Herein, we evaluated the levels of the immunological molecules (CXCL8, CCL2, CXCL9, CCL5, CXCL10, IL-6, TNF, IFN-γ, IL-17A, IL-4, IL-10, and IL-2) in the bone marrow plasma of 47 recently diagnosed B-cell acute lymphoblastic leukemia (B-ALL) patients during induction therapy using cytometric beads arrays. The results demonstrated that B-ALL patients showed high levels of CXCL9, CXCL10, IL-6, and IL-10 at the time of diagnosis, while at the end of induction therapy, a decrease in the levels of these immunological molecules and an increase in CCL5, IFN-γ, and IL-17A levels were observed. These findings indicate that B-ALL patients have an imbalance in chemokines and cytokines in the bone marrow microenvironment that contributes to suppressing the immune response. This immune imbalance may be associated with the presence of leukemic cells since, at the end of the induction therapy, with the elimination and reduction to residual cells, the proinflammatory profile is reestablished, characterized by an increase in the cytokines of the Th1 and Th17 profiles.

NLRP3-activated bone marrow dendritic cells play antileukemic roles via IL-1β/Th1/IFN-γ in acute myeloid leukemia

The bone marrow microenvironment of acute myeloid leukemia (AML) characterized by immunosuppressive features fosters leukemia immune escape. Elucidating the immunosuppressive mechanism and developing effective immunotherapeutic strategies are necessary. Here, we found that the Th1% and IFN-γ level were downregulated in bone marrow of AML and NLRP3-activated BMDCs promoted CD4⁺ T cell differentiation into Th1 cells via IL-1β secretion. However, IFN-γ-producing Th1 cells were not induced by NLRP3-activated BMDCs in the presence of the NLRP3 inflammasome inhibitor MCC950 or anti-IL-1β antibody in vitro unless exogenous IL-1β was replenished. This inhibitory effect on Th1 differentiation was also observed in Nlrp3^-/- mice or anti-IL-1β antibody-treated mice. Notably, elevated Th1 cell levels promoted apoptosis and inhibited proliferation in leukemia cells via IFN-γ secretion in vitro and in vivo. Thus, NLRP3-activated BMDCs promote the proliferation of IFN-γ-producing Th1 cells with antileukemic effects and may provide insight into the basis for leukemia immunotherapy in patients with AML.

Progranulin depletion inhibits proliferation via the transforming growth factor beta/SMAD family member 2 signaling axis in Kasumi-1 cells

Progranulin is an autocrine growth factor that promotes proliferation, migration, invasion, and chemoresistance of various cancer cells. These mechanisms mainly depend on the protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) pathway. Recent studies have shown that patients with hematopoietic cancer have elevated serum progranulin levels. Thus, the current study aimed to investigate the role of progranulin in hematopoietic cancer cells and how it modulates their proliferation. Both knockdown of progranulin and progranulin neutralizing antibody treatment inhibited proliferation in several human hematopoietic cancer cell lines. Moreover, progranulin depletion not only decreases the phosphorylation level of the Akt/mTOR pathway but also, surprisingly, increases the expression of transforming growth factor-beta (TGF-β) and phosphorylation of mothers against decapentaplegic homolog 2 (SMAD2) in Kasumi-1 cell. Furthermore, LY2109761, an inhibitor of TGF-β receptor type I/II kinase, and TGF-β neutralizing antibody blocked the inhibition of proliferation induced by progranulin depletion. These data provide new insights that progranulin alters cell proliferation via the TGF-β axis and progranulin could be a new therapeutic target for hematopoietic cancers.

A new cytokine-based dynamic stratification during induction is highly predictive of survivals in acute myeloid leukemia

The aim of this study was to assess the potential impact of the kinetics of serum levels of seven cytokines during induction in acute myeloid leukemia (AML) patients. Indeed, the role of cytokines, in the pathophysiology and response to therapy of AML patients, remains under investigation. Here, we report on the impact of peripheral levels of two cytokines, the Fms‐like tyrosine kinase 3 ligand (FL) and interleukin‐6 (IL‐6), evaluated during first‐line intensive induction. A new risk stratification can be proposed, which supersedes the ELN 2017 classification to predict survivals in AML patients by examining the kinetic profile of these cytokines during the induction phase. It segregates three groups of, respectively, high‐risk, characterized by a stagnation of low FL levels, intermediate risk, with dynamic increasing FL levels and high IL‐6 at day 22, and favorable risk with increasing FL levels but low IL‐6 at day 22.

Levels and Clinical Significance of Regulatory B Cells and T Cells in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy, whose immunological mechanisms are still partially uncovered. Regulatory B cells (Bregs) and CD4+ regulatory T cells (Tregs) are subgroups of immunoregulatory cells involved in modulating autoimmunity, inflammation, and transplantation reactions. Herein, by studying the number and function of Breg and Treg cell subsets in patients with AML, we explored their potential role in the pathogenesis of AML. Newly diagnosed AML patients, AML patients in complete remission, and healthy controls were enrolled. Flow cytometry was used to detect percentages of Bregs and Tregs. ELISA was conducted to detect IL-10 and TGF-β in plasma. The mRNA levels of IL-10 and Foxp3 were measured with RT-qPCR. The relationship of Bregs and Tregs with the clinicopathological parameters was analyzed. There was a significant reduction in the frequencies of Bregs and an increase of Tregs in newly diagnosed AML patients compared with healthy controls. Meanwhile, patients in complete remission exhibited levels of Bregs and Tregs comparable to healthy controls. Furthermore, compared with healthy controls and AML patients in complete remission, newly diagnosed AML patients had increased plasma IL-10 but reduced TGF-β. IL-10 and Foxp3 mRNA levels were upregulated in the newly diagnosed AML patients. However, there were no significant differences in IL-10 and Foxp3 mRNA levels between patients in complete remission and healthy controls. Bregs and Tregs have abnormal distribution in AML patients, suggesting that they might play an important role in regulating immune responses in AML.

Elevated plasma phage load as a marker for intestinal permeability in leukemic patients

Microbial translocation (MT) and altered gut microbiota have been described in acute leukemic patients and contribute to immune activation and inflammation. However, phage translocation has not been investigated in leukemia patients yet. We recruited 44 leukemic patients and 52 healthy adults and quantified the levels of 3 phages in peripheral blood, which were the most positive phages screened from fecal samples. The content of 16S rRNA in plasma was detected by qPCR to assess the intestinal mucosa of these patients. Spearman's rank correlation was used to analyze the relationship between phage load and the relevant clinical data. We found the most prevalent phages in fecal samples were λ phage, Wphi phage, and P22 phage, and λ phage had the highest detection rate in plasma (68%). Phage content was affected by chemotherapy and course of disease and correlated with the levels of CRP (r = 0.43, p = 0.003), sCD14 (r = 0.37, p = 0.014), and sCD163 (r = 0.44, p = 0.003). Our data indicate that plasma phage load is a promising marker for gut barrier damage and that gut phage translocation correlates with monocyte/macrophage activation and systemic inflammatory response in leukemic patients.

Initial absolute monocyte count as an immune biomarker for clinical response in acute myeloid leukemia with monocytic differentiation

BACKGROUND

Absolute monocyte count (AMC) correlates with survival outcomes in various hematologic malignancies. However, its role in myeloid malignancies including AML needs to be highlighted. So, this prospective cohort study aimed to assess the effect of AMC on the treatment outcome and survival in a 56 adult de novo AML patients with monocytic differentiation, admitted to the Clinical Hematology Unit, Internal Medicine Department, in a tertiary referral hospital in Egypt, from July 2016 to June 2019.

RESULTS

The initial AMC was measured either by manual differential or the hematology automatic analyzer Sysmex XN-2000 and patients were classified by using receiver operating characteristic curve into two groups monocytopenic (≤ 4 × 10⁹/L) and non-monocytopenic (> 4 × 10⁹/L) group; including 24 (42.9%) and 32 (57.1%) patients, respectively. After a median follow up period of 7.7 (range 0.5-33.2) months, the monocytopenic group was associated with a significantly higher CR rate (P = 0.019), with a lower death as well as relapse and early relapse rates (P = 0.011, 0.033, and 0.002, respectively). Moreover, low initial AMC along with intensive induction were independently associated with complete response to induction chemotherapy with HR, 5.04 [1.37-18.58], P = 0.015, and 5.67 [1.48-21.71], P = 0.011, respectively by using the multivariate logistic regression model. Regarding survival, the monocytopenic group was associated with a better 3-year disease-free survival rate (P = 0.011) in univariate Cox regression only but did not reach significance in the multivariate model and did not affect the overall survival as well.

CONCLUSION

Initial AMC was found to be an independent prognostic immune biomarker for treatment response in AML patients with monocytic differentiation. However, it did not appear as an independent predictor of survival in a multivariate analysis.

Alterations of T-cell-mediated immunity in acute myeloid leukemia

Acute myeloid leukemia (AML) is a systemic, heterogeneous hematologic malignancy with poor overall survival. While some malignancies have seen improvements in clinical outcomes with immunotherapy, success of these agents in AML remains elusive. Despite limited progress, stem cell transplantation and donor lymphocyte infusions show that modulation of the immune system can improve overall survival of AML patients. Understanding the causes of immune evasion and disease progression will identify potential immune-mediated targets in AML. This review explores immunosuppressive mechanisms that alter T-cell-mediated immunity in AML.

Interleukin-35 as an Emerging Player in Tumor Microenvironment

IL-35 is the newest member of IL-12 family. A dimeric protein consisting of two separate subunits has manifested suppressive actions on immune system, which is counterproductive in the context of cancers. Various reports have confirmed its inhibitory role on immune system which is carried out via formation of IL-35-producing regulatory T cells (iTr35), increased Treg development and suppressive Th17 cells growth. Although last decade has seen a great deal of scientific interest on this subject, the exact role, precise signal transduction and elaborative functions of IL-35 in tumor microenvironment (TME) remained elusive. Search for anti-IL-35 therapies have exhibited limited success in animal models. Contrarily, few studies have denied the idea that IL-35 plays a role in cancer. The purpose of this review is to analyze the reported scientific data on continuous symphony of IL-35 in cancers since the inception of former.

The cytokine network in acute myeloid leukemia (AML): A focus on pro- and anti-inflammatory mediators

Cytokines exert profound effects on the progression of hematopoietic malignancies such as acute myeloid leukemia (AML). Critical roles of cytokines in the context of inflammation have gained special interest. While pro-inflammatory mediators such as IL-1β, TNF-α and IL-6 tend to increase AML aggressiveness, anti-inflammatory mediators such as TGF-β and IL-10 appear to impede AML progression. Dysregulation of the complex interactions between pro- and anti-inflammatory cytokines in AML may create a pro-tumorigenic microenvironment with effects on leukemic cell proliferation, survival and drug-resistance. This article summarizes current knowledge about the functions of pro- and anti-inflammatory cytokines in AML, their modes of action, and therapeutic interventions with potential to improve clinical outcomes for AML patients.

Neuropathy correlated with imbalanced Foxp3/IL-17 in bone marrow microenvironment of patients with acute myeloid leukemia

Bone marrow (BM) neural tissues are important components of bone marrow microenvironment and play important roles in normal hematopoiesis. Neuropathy of BM can cause immunological alteration in hematopoietic microenvironment. It also can induce the impairment of normal hematopoiesis and promote the development of hematologic diseases. In the present study, we determined the expression levels and clinical significances of nerve-related molecules [nestin, tyrosine hydroxylase (TH), Glial Fibrillary Acidic protein (GFAP) and S100B] and T helper-related molecules (IL-17, Foxp3) in BM of AML patients and controls by immunohistochemical analysis and RT-PCR. Our results showed that the positive rates and expression levels of nestin, TH, GFAP and IL-17 were significantly decreased while Foxp3 and the ratio of Foxp3/IL-17 were statistically elevated in BM of AML patients. We found that there were significantly positive correlations between nestin with TH and IL-17 in BM of AML patients. We also observed significantly negative correlations between nestin with TH and Foxp3/IL-17 ratio. Moreover, the expression of nestin was positively correlated with the overall survival of AML patients. Our study suggests that neuropathy together with imbalanced T helper immunology in bone marrow might play important roles in AML.

Immunomodulatory Drugs: Immune Checkpoint Agents in Acute Leukemia

Intrinsic immune responses to acute leukemia are inhibited by a variety of mechanisms, such as aberrant antigen expression by leukemia cells, secretion of immunosuppressive cytokines and expression of inhibitory enzymes in the tumor microenvironment, expansion of immunoregulatory cells, and activation of immune checkpoint pathways, all leading to T cell dysfunction and/or exhaustion. Leukemic cells, similar to other tumor cells, hijack these inhibitory pathways to evade immune recognition and destruction by cytotoxic T lymphocytes. Thus, blockade of immune checkpoints has emerged as a highly promising approach to augment innate anti-tumor immunity in order to treat malignancies. Most evidence for the clinical efficacy of this immunotherapeutic strategy has been seen in patients with metastatic melanoma, where anti-CTLA-4 and anti-PD-1 antibodies have recently revolutionized treatment of this lethal disease with otherwise limited treatment options. To meet the high demand for new treatment strategies in acute leukemia, clinical testing of these promising therapies is commencing. Herein, we review the biology of multiple inhibitory checkpoints (including CTLA-4, PD-1, TIM-3, LAG-3, BTLA, and CD200R) and their contribution to immune evasion by acute leukemias. In addition, we discuss the current state of preclinical and clinical studies of immune checkpoint inhibition in acute leukemia, which seek to harness the body's own immune system to fight leukemic cells.

Higher PD-1 expression concurrent with exhausted CD8+ T cells in patients with de novo acute myeloid leukemia

Objective

To investigate the association between the T cell inhibitory receptor programmed death 1 (PD-1) and T cell exhaustion status in T cells from patients with de novo acute myeloid leukemia (AML) and AML in complete remission (CR).

Methods

Surface expression of PD-1 and the exhaustion and immunosenescence markers CD244 and CD57 on CD3+, CD4+ and CD8+ T cells from peripheral blood samples from 20 newly diagnosed, untreated AML patients and 10 cases with AML in CR was analyzed by flow cytometry. Twenty-three healthy individuals served as control.

Results

A significantly higher percentage of PD-1+ cells were found for CD3+ T cells in the de novo AML group compared with healthy controls. In addition, an increased level of PD-1+CD8+ T cells, but not PD-1+CD4+, was found for CD3+ T cells in the de novo AML and AML-CR samples. A higher percentage of CD244+CD4+, CD244+CD8+, CD57+CD4+ and CD57+CD8+ T cells was found in CD3+ T cells in samples from those with de novo AML compared with those from healthy controls. Strong increased PD-1+CD244+ and PD-1+CD57+ co-expression was found for CD4+ and CD8+ T cells in the de novo AML group compared with healthy controls.

Conclusions

We characterized the major T cell defects, including co-expression of PD-1 and CD244, CD57-exhausted T cells in patients with de novo AML, and found a particular influence on CD8+ T cells, suggesting a poor anti-leukemia immune response in these patients.

Common gamma chain cytokines in combinatorial immune strategies against cancer

Common γ chain (γC) cytokines, namely IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 are important for the proliferation, differentiation, and survival of lymphocytes that display antitumor activity, thus stimulating considerable interest for the use of cytokines in cancer immunotherapy. In this review, we will focus on the γC cytokines that demonstrate the greatest potential for immunotherapy, IL-2, IL-7, IL-15, and IL-21. We will briefly cover their biological function, potential applications in cancer therapy, and update on their use in combinatorial immune strategies for eradicating tumors and hematopoietic malignancies.

IL-35: a potential therapeutic target for controlling hepatitis B virus infection

Interleukin (IL)-35, a recently identified cytokine of the IL-12 family, is a potent immunosuppressive cytokine secreted by regulatory T (Treg) cells and the newly reported regulatory B (Breg) cells. IL-35 functions as a crucial immunosuppressive factor in immune-mediated diseases, and the predominant mechanism of suppression is its ability to suppress T cell proliferation and effector functions. The pathogenic processes of the non-cytopathic hepatitis B virus (HBV) infection-related liver diseases are immune-mediated, including liver damage and viral control. It has been found that IL-35 is detectable in peripheral CD4(+) T cells in chronic HBV-infected patients, whereas it is undetectable in healthy individuals. There is growing evidence that cytokine-mediated immune responses play a pivotal role in determining the clinical outcome during HBV infection. It is particularly important to investigate the effects of IL-35 in the immunopathogenesis of chronic HBV infection. In this study, the recent understanding of this issue is discussed.

The role of the IL-22/IL-22R1 axis in cancer

Interleukin-22 (IL-22) is an IL-10 family cytokine produced by T cells and innate lymphoid cells. The IL-22 signaling pathway orchestrates mucosal immune defense and tissue regeneration through pleiotropic effects including pro-survival signaling, cell migration, dysplasia and angiogenesis. While these functions can prevent initial establishment of tumors, they can also be hijacked by aggressive cancers to enhance tumor growth and metastasis. Thus, the role of the IL-22/IL-22R1 axis in cancer is complex and context-specific. Evidence of IL-22 involvement manifests as dysregulation of IL-22 expression and signaling in patients with many common cancers including those of the gut, skin, lung and liver. Unlike other cancer-associated cytokines, IL-22 has restricted tissue specificity as its unique receptor IL-22R1 is exclusively expressed on epithelial and tissue cells, but not immune cells. This makes it an attractive target for therapy as there is potential achieve anti-tumor immunity with fewer side effects. This review summarizes current findings on functions of IL-22 in association with general mechanisms for tumorigenesis as well as specific contributions to particular cancers, and ponders how best to approach further research in the field.