Natural killer (NK) cells play a crucial role in innate immunity, particularly in combating infections and tumors. However, in hematological cancers, NK cells often exhibit impaired functions. ...Therefore, it is very important to activate its endosomal Toll-like receptors (TLRs) as a potential strategy to restore its antitumor activity. We stimulated NK cells from the peripheral blood mononuclear cells from children with acute lymphoblastic leukemia and NK cells isolated, and the NK cells were stimulated with specific TLR ligands (Poly I:C, Imiquimod, R848, and ODN2006) and we evaluated changes in IFN-γ, CD107a, NKG2D, NKp44 expression, Granzyme B secretion, cytokine/chemokine release, and cytotoxic activity. Results revealed that Poly I:C and Imiquimod enhanced the activation of both immunoregulatory and cytotoxic NK cells, increasing IFN-γ, CD107a, NKG2D, and NKp44 expression. R848 activated immunoregulatory NK cells, while ODN2006 boosted CD107a, NKp44, NKG2D, and IFN-γ secretion in cytotoxic NK cells. R848 also increased the secretion of seven cytokines/chemokines. Importantly, R848 and ODN 2006 significantly improved cytotoxicity against leukemic cells. Overall, TLR stimulation enhances NK cell activation, suggesting TLR8 (R848) and TLR9 (ODN 2006) ligands as promising candidates for antitumor immunotherapy.
Resistance to chemotherapy hinders the successful treatment of acute lymphoblastic leukemia (ALL). The multi-drug resistance-1 (MDR1/ABCB1) gene encodes P-glycoprotein (P-gp), which plays an ...important role in chemoresistance; however, its transcriptional regulation remains unclear. We investigated the role of YY1 in the regulation of MDR1 and its relation to ALL outcomes. Analysis of the MDR1 promoter revealed four putative YY1-binding sites, which we analyzed using a reporter system and ChIP analysis. YY1 silencing resulted in the inhibition of MDR1 expression and function. The clinical roles of YY1 and MDR1 expression were evaluated in children with ALL. Expression of both proteins was increased in ALL patients compared to controls. We identified a positive correlation between YY1 and MDR1 expression. High levels of YY1 were associated with decreased overall survival. Our results demonstrated that YY1 regulates the transcription of MDR1. Therefore, YY1 may serve as a useful prognostic and/or therapeutic target.
Due to their increasing rates of morbidity and mortality, childhood malignancies are considered a global health priority, with acute lymphoblastic leukemias (ALLs) showing the highest incidence ...worldwide. Control of malignant clone emergence and the subsequent normal-leukemic hematopoietic cell out-competition require antitumor monitoring mechanisms. Investigation of cancer surveillance innate cells may be critical to understand the mechanisms contributing in either disease progression or relapse, and to promote displacement of leukemic hematopoiesis by the normal counterpart. We report here that NK cell production is less and low hematopoietic progenitor numbers contribute to this defect. By investigating the expression of the activation molecule class I restricted T-cell associated molecule (CRTAM) along the hematopoietic lineage differentiation pathway, we have identified lymphoid precursor populations coexpressing CD34, CD56/CD3/CD19, and CRTAM as the earliest developmental stage where activation may take place in specialized niches that display the ligand nectin-like-2. Of note, bone marrow (BM) from patients with ALL revealed high contents of preactivated CD56
NK cells expressing CRTAM and endowed with an exhaustion-like phenotype and the functional capability of producing IL-10 and TGF-β in vitro. Our findings suggest, for the first time, that the tumor microenvironment in ALL directly contribute to exhaustion of NK cell functions by the CRTAM/Necl-2 interaction, and that the potential regulatory role of exhausted-like NK cells may favor malignant progression at the expense of anti-tumor responses. Phenotypic and functional identity of this unique suppressor-like NK cell population within the leukemic BM would be of special interest for the pathobiology of ALL and development of targeting strategies.
N-3 polyunsaturated fatty acids (LCPUFA-ω3), particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) might have beneficial effects on lean mass and fat mass synthesis.
To investigate ...the effect of LCPUFA-ω3 supplementation on body composition changes in children with acute lymphoblastic leukemia (ALL) at remission and three months (3 mo) after supplementation.
This randomized controlled trial enrolled 72 children (3-13 y) with newly diagnosed ALL (placebo group 500 mg sunflower oil: 36 patients; LCPUFA-ω3 group 225 mg DHA, 45 mg EPA: 36 patients). LCPUFA-ω3 was administered at 0.100 g/kg of body weight/day for 3 mo. Both groups were provided with an oral milkshake supplement.
Body composition was measured at diagnosis, remission, and 3 months after supplementation by dual-energy X-ray absorptiometry (DXA). Red blood cell fatty acid analyses were performed with gas chromatography. Student's t test compared the percentage changes in body weight, total body fat percentage (TBFP), and lean body mass (LBM) between the groups. The Mann-Whitney U test was used to compare the groups, and the Friedman range test and Wilcoxon signed rank test were used for intratreatment comparisons. Spearman correlation coefficients were calculated for LBM and erythrocyte LCPUFA-ω3 content.
LBM decreased significantly in both groups. This loss was greater in the placebo group than in the LCPUFA-ω3 group at remission (p = 0.044) and at 3 months of supplementation (p = 0.039). There were significant and progressive increases in DHA and EPA concentrations in the LCPUFA-ω3 group (p < 0.001). LBM at remission was directly correlated with increased DHA (r = 0.487, p = 0.034) and EPA (r = 0.499, p = 0.030) erythrocytes in the LCPUFA-ω3 group.
At ALL diagnosis and during the first three months of treatment, 100 mg/kg of body weight/d DHA and EPA decreased LBM loss and allowed the incorporation of fatty acids into cell membranes (clinicaltriasl.gov #: NCT01051154).
Pediatric oncology, notably childhood acute lymphoblastic leukemia (ALL), is currently one of the health-leading concerns worldwide and a biomedical priority. Decreasing overall leukemia mortality in ...children requires a comprehensive understanding of its pathobiology. It is becoming clear that malignant cell-to-niche intercommunication and microenvironmental signals that control early cell fate decisions are critical for tumor progression. We show here that the mesenchymal stromal cell component of ALL bone marrow (BM) differ from its normal counterpart in a number of functional properties and may have a key role during leukemic development. A decreased proliferation potential, contrasting with the strong ability of producing pro-inflammatory cytokines and an aberrantly loss of CXCL12 and SCF, suggest that leukemic lymphoid niches in ALL BM are unique and may exclude normal hematopoiesis. Cell competence
assays within tridimensional coculture structures indicated a growth advantage of leukemic precursor cells and their niche remodeling ability by CXCL12 reduction, resulting in leukemic cell progression at the expense of normal niche-associated lymphopoiesis.
To identify the type of infections and risk factors for infection-related mortality (IRM) after allogeneic hematopoietic stem cell transplantation (HSCT). Retrospective cohort study of patients <16 ...years of age treated in 2010-2019 was conducted. Unadjusted hazard ratios (HR) and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CIs) were estimated using Cox regression. Cumulative incidence was calculated. Data for 99 pediatric patients were analyzed. The myeloablative conditioning was the most used regimen (78.8%) and the hematopoietic stem cell source was predominantly peripheral blood (80.8%). Primary graft failure occurred in 19.2% of patients. Frequency of acute graft-versus-host disease was 46.5%. Total of 136 infectious events was recorded, the most common of which were bacterial (76.4%) followed by viral infection (15.5%) and then fungal infection (8.1%). The best predictors for infection subtypes where the following: a) for bacterial infection (the age groups of 10.1-15 years: aHR = 3.33; 95% CI: 1.62-6.85 and. >15 years: aHR = 3.34; 95% CI: 1.18-9.45); b) for viral infection (graft versus host disease: aHR = 5.36; 95% CI: 1.62-17.68), however, for fungal infection statistically significant predictors were not identified. Related mortality was 30% (n = 12). Increased risk for infection-related mortality was observed in patients with unrelated donor and umbilical cord stem cells recipients (HR = 3.12; 95% CI: 1.00-9.85). Frequencies of infections and infection-related mortality appear to be similar to those reported. Unrelated donors and stem cells from umbilical cord recipients were associated with a high risk of mortality.
NK cells represent a heterogeneous subpopulation of lymphocytes of the innate immune system, which possess powerful antitumor activity. NK cells exhibit their function through a complex collection of ...receptors that act synergistically to recognize, regulate, or amplify the immune response. TLRs allow cells to detect PAMPs, MAMPs, or DAMPs, which are essential for the initiation of the immune response. Studies on the different subpopulations of NK cells and their expression profile of innate immune receptors in hematological cancers are limited. In this study, the specific subpopulations of NK cells in pediatric patients with acute lymphoblastic leukemia (ALL) and the repertoire and level of expression of TLRs in cytotoxic NK cells were assessed. The results suggested that pediatric patients with ALL exhibited a significant decrease in NK cells in peripheral blood and bone marrow, in addition to alterations in the distribution of the subpopulations of cells. Regulatory and cytotoxic NK cells were diminished, whereas dysfunctional phenotype was considerably increased. Cytotoxic NK cells from children with ALL expressed all 10 TLRs, and expression of TLR1 and TLR9 was decreased compared with the controls. Interestingly, cytotoxic NK cells exhibited a higher expression of TLR1 in the bone marrow than in the peripheral blood of patients with ALL. The present study is the first to show that TLR10 was expressed in the cytotoxic NK cells and the first to assess the profile and levels of the 10 known TLRs in cytotoxic NK cells from patients with ALL. The alterations in expression levels and cellular distribution may be involved in the immune response.
Zika virus (ZIKV) can cause neurological issues in infants. To provide protection, neutralizing antibodies should be transferred from the mother to the infant. We conducted a study at the Hospital ...General de Pochutla, Oaxaca, Mexico. Samples were collected from mothers (blood and breast milk) and infants (saliva and dried blood spots) within the first 12 postnatal hours (December 2017 to February 2018) and tested for ZIKV total and neutralizing antibodies as well as ZIKV-PCR. Microcephaly was evaluated according to INTERGROWTH-21st standards. Maternal IgG seroprevalence was 28.4% with 10.4% active infection, while infant IgG seroprevalence was 5.5% with 2.4% active infection. There were two cases of virolactia, and 6.3% of the infant saliva samples tested positive for ZIKV. Additionally, 18.3% of the infants were in a cephalic perimeter percentile lower than 10 and had an association between microcephaly and serology or a PCR between 8.6 and 60.9%. The infant blood samples had neutralizing antibodies, indicating intrauterine protection. Microcephaly was correlated with serology or PCR, but in our study population, non-ZIKV factors may be involved as well. Low ZIKV infection values in breast milk mean that breastfeeding is safe in most of the mothers and infants of the endemic area studied.
Background
Recurrent genetic alterations contributing to leukemogenesis have been identified in pediatric B-cell Acute Lymphoblastic Leukemia (B-ALL), and some are useful for refining classification, ...prognosis, and treatment selection.
IKZF1
plus
is a complex biomarker associated with a poor prognosis. It is characterized by
IKZF1
deletion coexisting with
PAX5
,
CDKN2A/2B
, or PAR1 region deletions. The mutational spectrum and clinical impact of these alterations have scarcely been explored in Mexican pediatric patients with B-ALL. Here, we report the frequency of the
IKZF1
plus
profile and the mutational spectrum of
IKZF1, PAX5, CDKN2A/2B
, and
ERG
genes and evaluate their impact on overall survival (OS) in a group of patients with B-ALL.
Methods
A total of 206 pediatric patients with
de novo
B-ALL were included. DNA was obtained from bone marrow samples at diagnosis before treatment initiation. A custom-designed next-generation sequencing panel was used for mutational analysis. Kaplan-Meier analysis was used for OS estimation.
Results
We identified the
IKZF1
plus
profile in 21.8% of patients, which was higher than that previously reported in other studies. A significantly older age (
p=0.04
), a trend toward high-risk stratification (
p=0.06
), and a decrease in 5-year Overall Survival (OS) (
p=0.009
) were observed, although heterogeneous treatment protocols in our cohort would have impacted OS. A mutation frequency higher than that reported was found for
IKZF1
(35.9%) and
CDKN2A/2B
(35.9%) but lower for
PAX5
(26.6%).
IKZF1
MUT
group was older at diagnosis (
p=0.0002
), and most of them were classified as high-risk (73.8%,
p=0.02
), while patients with
CDKN2A/2B
MUT
had a higher leukocyte count (
p=0.01
) and a tendency toward a higher percentage of blasts (98.6%, >50% blasts,
p=0.05
) than the non-mutated patients. A decrease in OS was found in
IKZF1
MUT
and
CDKN2A/2B
MUT
patients, but the significance was lost after
IKZF1
plus
was removed.
Discussion
Our findings demonstrated that Mexican patients with B-ALL have a higher prevalence of genetic markers associated with poor outcomes. Incorporating genomic methodologies into the diagnostic process, a significant unmet need in low- and mid-income countries, will allow a comprehensive identification of relevant alterations, improving disease classification, treatment selection, and the general outcome.
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