Intracellular cytokine profile of T cells from children with acute lymphoblastic leukemia

Immune Microenvironment in Childhood Cancers: Characteristics and Therapeutic Challenges

The tumor immune microenvironment is pivotal in cancer initiation, advancement, and regulation. Its molecular and cellular composition is critical throughout the disease, as it can influence the balance between suppressive and cytotoxic immune responses within the tumor's vicinity. Studies on the tumor immune microenvironment have enriched our understanding of the intricate interplay between tumors and their immunological surroundings in various human cancers. These studies illuminate the role of significant components of the immune microenvironment, which have not been extensively explored in pediatric tumors before and may influence the responsiveness or resistance to therapeutic agents. Our deepening understanding of the pediatric tumor immune microenvironment is helping to overcome challenges related to the effectiveness of existing therapeutic strategies, including immunotherapies. Although in the early stages, targeted therapies that modulate the tumor immune microenvironment of pediatric solid tumors hold promise for improved outcomes. Focusing on various aspects of tumor immune biology in pediatric patients presents a therapeutic opportunity that could improve treatment outcomes. This review offers a comprehensive examination of recent literature concerning profiling the immune microenvironment in various pediatric tumors. It seeks to condense research findings on characterizing the immune microenvironment in pediatric tumors and its impact on tumor development, metastasis, and response to therapeutic modalities. It covers the immune microenvironment's role in tumor development, interactions with tumor cells, and its impact on the tumor's response to immunotherapy. The review also discusses challenges targeting the immune microenvironment for pediatric cancer therapies.

Systemic immunological profile of children with B-cell acute lymphoblastic leukemia: performance of cell populations and soluble mediators as serum biomarkers

Background

Children with B-cell acute lymphoblastic leukemia (B-ALL) have an immune imbalance that is marked by remodeling of the hematopoietic compartment, with effects on peripheral blood (PB). Although the bone marrow (BM) is the main maintenance site of malignancy, the frequency with which immune cells and molecules can be monitored is limited, thus the identification of biomarkers in PB becomes an alternative for monitoring the evolution of the disease.

Methods

Here, we characterize the systemic immunological profile in children undergoing treatment for B-ALL, and evaluate the performance of cell populations, chemokines and cytokines as potential biomarkers during clinical follow-up. For this purpose, PB samples from 20 patients with B-ALL were collected on diagnosis (D0) and during induction therapy (days 8, 15 and 35). In addition, samples from 28 children were used as a control group (CG). The cellular profile (NK and NKT-cells, Treg, CD3+ T, CD4+ T and CD8+ T cells) and soluble immunological mediators (CXCL8, CCL2, CXCL9, CCL5, CXCL10, IL-6, TNF, IFN-γ, IL-17A, IL- 4, IL-10 and IL-2) were evaluated via flow cytometry immunophenotyping and cytometric bead array assay.

Results

On D0, B-ALL patients showed reduction in the frequency of cell populations, except for CD4+ T and CD8+ T cells, which together with CCL2, CXCL9, CXCL10, IL-6 and IL-10 were elevated in relation to the patients of the CG. On D8 and D15, the patients presented a transition in the immunological profile. While, on D35, they already presented an opposite profile to D0, with an increase in NKT, CD3+ T, CD4+ T and Treg cells, along with CCL5, and a decrease in the levels of CXCL9, CXCL10 and IL-10, thus demonstrating that B-ALL patients present a complex and dynamic immune network during induction therapy. Furthermore, we identified that many immunological mediators could be used to classify the therapeutic response based on currently used parameters.

Conclusion

Finally, it is noted that the systemic immunological profile after remission induction still differs significantly when compared to the GC and that multiple immunological mediators performed well as serum biomarkers.

Atopy manifestations in pediatric patients with acute lymphoblastic leukemia: correlation assessment with interleukin-4 (IL-4) and IgE level

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common type of cancer in the age range of under 15 years old and accounts for 25-30% of all childhood cancers. Although conventional chemotherapy regimens are used to improve the overall survival rate, it has been associated with some complications, amongst which allergic manifestations with unknown mechanisms are more common.

METHODS

Our study compared serum IgE and IL-4 concentration, as a hallmark of allergic responses in pediatric ALL patients before and after 6 months of intensive (high-dose) chemotherapy, to show whether changes in the level of these markers may be associated with atopy. Serum level of IL-4 and IgE was measured using enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

The results showed that the level of IgE and IL-4 increased following chemotherapy in both ALL patients with and without atopy. In addition, post-chemotherapy treatment IgE and IL-4 levels were significantly elevated in patients with atopy compared to those without it. The difference between baseline and post-chemotherapy level of IgE and IL-4 was significantly higher in patients with atopy compared to those without it.

CONCLUSIONS

To the best of our knowledge, this is the first study that showed a connection between post-chemotherapy allergic manifestations in pediatric ALL patients and IL-4 and IgE level. Flow cytometry analysis of the T-helper 2 (Th2) lymphocytes and other allergy-related T cell subsets like Tc2 and Th9 as well as the study of the genetic variations in atopy-related genes like IL-4/IL-4R, IL-5, IL-9, IL-13, and high affinity FcεRI IgE receptor and also HLA genes is necessary to clearly define the underlying mechanism responsible for post-chemotherapy hypersensitivity reaction in pediatric ALL patients.

Mechanisms of Immunosuppressive Tumor Evasion: Focus on Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a malignancy with high heterogeneity in its biological features and treatments. Although the overall survival (OS) of patients with ALL has recently improved considerably, owing to the application of conventional chemo-therapeutic agents, approximately 20% of the pediatric cases and 40-50% of the adult patients relapse during and after the treatment period. The potential mechanisms that cause relapse involve clonal evolution, innate and acquired chemoresistance, and the ability of ALL cells to escape the immune-suppressive tumor response. Currently, immunotherapy in combination with conventional treatment is used to enhance the immune response against tumor cells, thereby significantly improving the OS in patients with ALL. Therefore, understanding the mechanisms of immune evasion by leukemia cells could be useful for developing novel therapeutic strategies.

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.

Oral Health, Caries Risk Profiles, and Oral Microbiome of Pediatric Patients with Leukemia Submitted to Chemotherapy

Background

Chemotherapy is the primary treatment modality used for patients with acute lymphoblastic leukemia (ALL), but inevitably causes microbiota-related oral complications. This study is aimed at investigating the effects of chemotherapy on oral health status, caries risk, and oral microbiome in pediatric patients with ALL.

Methods

Thirty-nine children with ALL receiving chemotherapy were enrolled, and a gender-, age-, dentition stage, and socioeconomic class matched healthy counterpart were recruited. Demographic information and overall health condition were obtained through the questionnaire and medical records. Oral examination was performed to assess caries and salivary status, plaque index, and other oral manifestations. Cariogram was used to assess the overall caries risk. Supragingival samples of thirteen ALL subjects and their counterparts were randomly selected to perform a 16S ribosomal RNA gene 454 pyrosequencing. Raw sequence data were screened, trimmed, and filtered using Seqcln and MOTHUR.

Results

The prevalence of dental caries, gingivitis, oral mucositis, xerostomia, and candidiasis in ALL groups was higher than that of the control group (p < 0.05). Children with ALL demonstrated higher caries risk compared to healthy controls (HC) based upon Cariogram (p < 0.05). The oral microbial structure of ALL patients receiving chemotherapy is different from that of healthy controls. Oral microbiota of ALL groups showed less alpha diversity and significant differences in the composition of the oral microbiome compared to healthy controls.

Conclusions

ALL patients receiving chemotherapy demonstrated compromised oral health, high caries risk, alteration of caries-related factors, and dysbiosis of oral microbiota. These findings may be of clinical importance in developing better strategies for personalized preventive management of oral diseases for pediatric children with ALL.

Variability of ex-vivo stimulated T-cells secretory profile in healthy subjects

Peripheral blood lymphocytes (PBL) are able to synthesize various cytokines that play key roles in the immune response and intercellular signaling. Since alterations in cytokine production and/or activity occur in many pathological processes, the study of cytokine synthetic capacity of PBL is a valuable tool for assessing the immune profile. In this paper, we aimed to investigate the variability of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α) and interferon gamma (IFN-γ) synthetic capacity of CD4+/CD8+ T-cells stimulated ex-vivo in healthy subjects, by means of a commercial intracellular cytokine staining (ICS) protocol. Peripheral blood mononuclear cells were isolated from 16 healthy subjects by Ficoll gradient centrifugation and activated ex-vivo with PMA/Ionomycin/Brefeldin-A for 4 hours. Activated PBL were surface-stained for CD3/CD4/CD8, fixed and permeabilized. ICS was performed using anti-human IL-2/TNF-α/IFN-γ and samples were analyzed on a BD-FACSAria-III flow cytometer. We recorded high post-isolation and post-activation mean viabilities: 82.1% and 82.4% respectively, p=0.84. Both CD4+/CD8+ subpopulations were found to partially produce each of the three cytokines, but in different proportions. On average, a significantly greater percentage of CD4+ cells was shown to produce IL-2 and TNF-α, compared with CD8+ cells (61.5%+/-5.8 vs. 25%+/-5.6 and 26.9%+/-11 vs. 7.5%+/-3.3 respectively, p---lt---0.0001 for both). Contrarily, IFN-γ was produced by a higher proportion of CD8+ cells (8.4%+/-3.9 vs. 6.8%+/-3.2, p=0.01). These results show that the employed ICS protocol elicits a satisfactory and consistent cytokine response from PBL of healthy subjects. The collected data may be used to outline a preliminary reference range for future studies on both healthy/pathological subjects.

The Clinical Link between Human Intestinal Microbiota and Systemic Cancer Therapy

Clinical interest in the human intestinal microbiota has increased considerably. However, an overview of clinical studies investigating the link between the human intestinal microbiota and systemic cancer therapy is lacking. This systematic review summarizes all clinical studies describing the association between baseline intestinal microbiota and systemic cancer therapy outcome as well as therapy-related changes in intestinal microbiota composition. A systematic literature search was performed and provided 23 articles. There were strong indications for a close association between the intestinal microbiota and outcome of immunotherapy. Furthermore, the development of chemotherapy-induced infectious complications seemed to be associated with the baseline microbiota profile. Both chemotherapy and immunotherapy induced drastic changes in gut microbiota composition with possible consequences for treatment efficacy. Evidence in the field of hormonal therapy was very limited. Large heterogeneity concerning study design, study population, and methods used for analysis limited comparability and generalization of results. For the future, longitudinal studies investigating the predictive ability of baseline intestinal microbiota concerning treatment outcome and complications as well as the potential use of microbiota-modulating strategies in cancer patients are required. More knowledge in this field is likely to be of clinical benefit since modulation of the microbiota might support cancer therapy in the future.

IFNG +874 A/T is associated with acute lymphoblastic leukemia in Mexican Mestizos

Acute lymphoblastic leukemia (ALL), the most common type of cancer in children worldwide, has one of the highest incidence rates in Mexico. It is a multifactorial disease and different cytokine single nucleotide polymorphisms (SNP), have been associated with ALL expression. Few studies have been published analyzing IFNG +874 T/A and IL2 -330 G/T in this type of leukemia. These SNPs are involved in high or low expression, and are central to cellular immunity, influencing greatly tumor growth. The purpose of this work was to explore the association of IFNG +874 A/T (rs2430561) and IL2 -330 G/T (rs2069762) SNPs with ALL susceptibility and/or protection in 488 Mexican Mestizos patients, as compared to 950 Mexican Mestizo healthy controls. The results demonstrated that IFNG +874 T allele (pc = 0.00004, OR = 0.673) and the TT genotype (pc = 0.00015, OR = 0.349), protect against ALL expression with no specific gender association; however, the TT homozygote genotype (vs. TA+AA) seems more protective in males (pc = 0.00683). IL2 -330 G/T does not contribute to the development of ALL. In healthy Mexicans, the most common genotypes for IL2 and IFNG, are the low cytokine producers, suggesting that the genetic background in this ethnic group, may be partly responsible for the high incidence of ALL. These results show for the first time in Mexicans, the relevant role that IFNG SNP has in the genetic etiology of ALL. Thus, a large group of patients belonging to different ethnicities will be very helpful to study in order to demonstrate if these SNPs contribute to the genetic etiology of ALL, as shown here in Mexican Mestizos.

Gastrointestinal microbial populations can distinguish pediatric and adolescent Acute Lymphoblastic Leukemia (ALL) at the time of disease diagnosis

Background

An estimated 15,000 children and adolescents under the age of 19 years are diagnosed with leukemia, lymphoma and other tumors in the USA every year. All children and adolescent acute leukemia patients will undergo chemotherapy as part of their treatment regimen. Fortunately, survival rates for most pediatric cancers have improved at a remarkable pace over the past three decades, and the overall survival rate is greater than 90 % today. However, significant differences in survival rate have been found in different age groups (94 % in 1–9.99 years, 82 % in ≥10 years and 76 % in ≥15 years). ALL accounts for about three out of four cases of childhood leukemia. Intensive chemotherapy treatment coupled with prophylactic or therapeutic antibiotic use could potentially have a long-term effect on the resident gastrointestinal (GI) microbiome. The composition of GI microbiome and its changes upon chemotherapy in pediatric and adolescent leukemia patients is poorly understood. In this study, using 16S rRNA marker gene sequences we profile the GI microbial communities of pediatric and adolescent acute leukemia patients before and after chemotherapy treatment and compare with the microbiota of their healthy siblings.

Results

Our study cohort consisted of 51 participants, made up of matched pediatric and adolescent patients with ALL and a healthy sibling. We elucidated and compared the GI microbiota profiles of patients and their healthy sibling controls via analysis of 16S rRNA gene sequencing data. We assessed the GI microbiota composition in pediatric and adolescent patients with ALL during the course of chemotherapy by comparing stool samples taken before chemotherapy with stool samples collected at varying time points during the chemotherapeutic treatment. The microbiota profiles of both patients and control sibling groups are dominated by members of Bacteroides, Prevotella, and Faecalibacterium. At the genus level, both groups share many taxa in common, but the microbiota diversity of the patient group is significantly lower than that of the control group. It was possible to distinguish between the patient and control groups based on their microbiota profiles. The top taxa include Anaerostipes, Coprococcus, Roseburia, and Ruminococcus2 with relatively higher abundance in the control group. The observed microbiota changes are likely the result of several factors including a direct influence of therapeutic compounds on the gut flora and an indirect effect of chemotherapy on the immune system, which, in turn, affects the microbiota.

Conclusions

This study provides significant information on GI microbiota populations in immunocompromised children and opens up the potential for developing novel diagnostics based on stool tests and therapies to improve the dysbiotic condition of the microbiota at the time of diagnosis and in the earliest stages of chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2965-y) contains supplementary material, which is available to authorized users.

Baicalin from the extract of Scutellaria baicalensis affects the innate immunity and apoptosis in leukocytes of children with acute lymphocytic leukemia

Scutellariae Radix (root of Scutellaria baicalensis) has a long history of application in traditional and in modern herbal medications. The major components of Scutellariae Radix are baicalin, baicalein, wogonoside and wogonin. Accumulating evidence demonstrates that Scutellaria has immunomodulatory effects and possesses compelling anticancer potential. Treatment of peripheral blood leukocytes (PBLs) with Scutellaria extract (SBE) enriched in baicalin, reduced viability of PBLs obtained from patients with acute lymphoblastic leukemia (ALL). SBE had no impact on the survival of healthy, control leukocytes. The immune system modulation by SBE resulted in increased production of IFNγ in PBLs, and reduced TNFα and IL-10 production in bone marrow cells (BMC), in ALL patients. SBE stimulated the nonspecific antiviral immunity, assessed by resistance of PBLs and BMC to vesicular stomatitis virus (VSV) infection. SBE showed pro-apoptotic activity in NALM-6 cell line (B-type human leukemia). The number of cells expressing annexin V increased from 6% in control cultures to 29% and 52% after treatment with 100 μg/ml and 200 μg/ml respectively. Increased percentage of apoptotic cells was observed when cells were treated with corresponding concentration of baicalin. SBE enhanced apoptosis of PBLs in BMC of leukemic children. The percentage of PBLs that underwent apoptosis and mean annexin V expression increased from 11% in the control to 17% and 24% for the doses of 100 μg/ml and 200 μg/ml respectively. Importantly, SBE did not induce apoptosis of PBLs in the healthy, control group.

Oral microbiota distinguishes acute lymphoblastic leukemia pediatric hosts from healthy populations

In leukemia, oral manifestations indicate aberrations in oral microbiota. Microbiota structure is determined by both host and environmental factors. In human hosts, how health status shapes the composition of oral microbiota is largely unknown. Taking advantage of advances in high-throughput sequencing, we compared the composition of supragingival plaque microbiota of acute lymphoblastic leukemia (ALL) pediatric patients with healthy controls. The oral microbiota of leukemia patients had lower richness and less diversity compared to healthy controls. Microbial samples clustered into two major groups, one of ALL patients and another of healthy children, with different structure and composition. Abundance changes of certain taxa including the Phylum Firmicutes, the Class Bacilli, the Order Lactobacillales, the Family Aerococcaceae and Carnobacteriaceae, as well as the Genus Abiotrophia and Granulicatella were associated with leukemia status. ALL patients demonstrated a structural imbalance of the oral microbiota, characterized by reduced diversity and abundance alterations, possibly involved in systemic infections, indicating the importance of immune status in shaping the structure of oral microbiota.

Immune defects in the risk of infection and response to vaccination in monoclonal gammopathy of undetermined significance and multiple myeloma

The plasma cell proliferative disorders monoclonal gammopathy of undetermined significance (MGUS) and malignant multiple myeloma (MM) are characterized by an accumulation of transformed clonal plasma cells in the bone marrow and production of monoclonal immunoglobulin. They typically affect an older population, with median age of diagnosis of approximately 70 years. In both disorders, there is an increased risk of infection due to the immunosuppressive effects of disease and conjointly of therapy in MM, and response to vaccination to counter infection is compromised. The underlying factors in a weakened immune response in MGUS and MM are as yet not fully understood. A confounding factor is the onset of normal aging, which quantitatively and qualitatively hampers humoral immunity to affect response to infection and vaccination. In this review, we examine the status of immune alterations in MGUS and MM and set these against normal aging immune responses. We focus primarily on quantitative and functional aspects of B-cell immunity. Furthermore, we review the current knowledge relating to susceptibility to infectious disease in MGUS and MM, and how efficacy of conventional vaccination is affected by proliferative disease-related and therapy-related factors.

Increased Th22 cells as well as Th17 cells in patients with adult T-cell acute lymphoblastic leukemia

BACKGROUND

Immune regulation is important for the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL). Th22 cells are recently-identified CD4(+) T cells that implicated in the pathogenesis of many hematological diseases, such as AML. However, the role of Th22 cells in the pathophysiology of T-ALL remains unclear. We examined the Th22, Th17 and Th1 cell frequencies in peripheral blood of T-ALL patients.

METHODS

We studied 24 newly-diagnosed (ND), 17 morphologic complete remission (CR) T-ALL patients and 30 healthy controls. Th subsets were examined by flow cytometry. Plasma IL-22 and IL-17 concentrations were measured by ELISA. Transcription factor RORC, T-bet and AHR mRNA expressions were examined by RT-PCR.

RESULTS

Th22, Th17 frequencies, plasma IL-22 concentration and AHR expression were significantly increased in ND or CR T-ALL patients compared with controls. Moreover, Th22 showed positive correlation with Th17 or Th1 cells in T-ALL patients. However, a significant decrease of IL-17 concentration, Th1 frequency and T-bet expression was found in ND or CR ALL patients compared with controls. Furthermore, Th17 cells showed positive correlation but Th1 cells showed negative correlation with white blood cell counts.

CONCLUSION

The profile of Th subsets was distinct for T-ALL patients and showed some correlations with clinical index, which suggest that these Th subsets may be implicated in the pathogenesis of T-ALL and be reasonable targets for therapeutic intervention.

A systematic analysis of a mi-RNA inter-pathway regulatory motif

BACKGROUND

The continuing discovery of new types and functions of small non-coding RNAs is suggesting the presence of regulatory mechanisms far more complex than the ones currently used to study and design Gene Regulatory Networks. Just focusing on the roles of micro RNAs (miRNAs), they have been found to be part of several intra-pathway regulatory motifs. However, inter-pathway regulatory mechanisms have been often neglected and require further investigation.

RESULTS

In this paper we present the result of a systems biology study aimed at analyzing a high-level inter-pathway regulatory motif called Pathway Protection Loop, not previously described, in which miRNAs seem to play a crucial role in the successful behavior and activation of a pathway. Through the automatic analysis of a large set of public available databases, we found statistical evidence that this inter-pathway regulatory motif is very common in several classes of KEGG Homo Sapiens pathways and concurs in creating a complex regulatory network involving several pathways connected by this specific motif. The role of this motif seems also confirmed by a deeper review of other research activities on selected representative pathways.

CONCLUSIONS

Although previous studies suggested transcriptional regulation mechanism at the pathway level such as the Pathway Protection Loop, a high-level analysis like the one proposed in this paper is still missing. The understanding of higher-level regulatory motifs could, as instance, lead to new approaches in the identification of therapeutic targets because it could unveil new and "indirect" paths to activate or silence a target pathway. However, a lot of work still needs to be done to better uncover this high-level inter-pathway regulation including enlarging the analysis to other small non-coding RNA molecules.

Protective effects of diosmetin extracted from Galium verum L. on the thymus of U14-bearing mice

Diosmetin (DGVL) extracted from the traditional Chinese herb Galium verum L. has been found to have anticancer activity. In this study, the effects of DGVL on the thymus of U14-bearing mice were investigated. Using flow cytometry, peripheral blood lymphocytes were characterized based on the expression of surface markers for T helper cells (CD4+) and T suppressor cells (CD8+). Serum levels of tumor necrosis factor α (TNF-α), interleukin-2 (IL-2), IL-10, and transforming growth factor β1 (TGF-β1) and a cell proliferation assay were determined with an enzyme-linked immunosorbent assay. The expression of Fas and Fas ligand (FasL) on the thymus was determined by Western blotting. Our results showed that DGVL inhibited tumor growth and significantly increased the thymus weight compared with the control. Also, DGVL elevated serum levels of IL-2 and significantly reduced levels of TNF-α, TGF-β1, and IL-10 in a dose-dependent manner. Histological study and terminal dUTP nick end labeling staining results showed that DGVL protected thymus tissue against the onslaught of tumor growth by inhibiting thymus lymphocyte apoptosis. The cell proliferation assay revealed that DGVL might promote more thymus lymphocytes towards proliferation. Furthermore, the ratio of CD4+/CD8+ T lymphocytes was significantly increased from 0.69 to 2.29 by treatment with DGVL. Immunoblotting analyses revealed that the expression of Fas and FasL on the thymus was lower in mice in the DGVL treatment group than in the control mice. In conclusion, DGVL can inhibit tumor growth and protect tumor-induced apoptosis of the thymus, and the mechanism is closely associated with reduced cell death in the thymus and a Fas–FasL-dependent pathway.

Maternal use of antibiotics and cancer in the offspring: results of a case-control study in Germany

OBJECTIVE

As previous results were inconsistent, we assessed the association between maternal use of antibiotics during pregnancy or 3 months before conception and childhood cancer in the offspring in a large case-control study in Germany.

METHODS

This population-based study on potential risk factors for childhood cancer was conducted by the German Childhood Cancer Registry (GCCR) and included a total of 1,867 registered cancer cases aged 0-14, diagnosed between October 1992 and September 1994. A total of 2,057 controls were randomly drawn from population registries, matched by age, gender, and region. Conditional logistic regression models for frequency-matched datasets were used to estimate odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

Positive statistically significant associations with self-reported maternal antibiotic use were observed for acute lymphoid leukemia (based on 59 mothers exposed to antibiotics, OR = 1.47; 95% CI: 1.06-2.04), acute myeloid leukemia (18 exposed, OR = 3.21; 95% CI: 1.83-5.62), and Burkitt lymphoma (three exposed, OR = 5.89; 95% CI: 1.47-23.69), but not other cancer types.

CONCLUSIONS

The results provide some support for the hypothesis that maternal use of antibiotics increases the risk of cancer in the offspring. Although recall bias is a concern, it is unlikely that this fully explains the observed effect. Further, the observed associations might be related to the underlying infections.

Dysregulation in T helper 1/T helper 2 cytokine ratios in patients with multiple myeloma

We have assessed alterations of Th1 and Th2 derived cytokines in the progression of multiple myeloma (MM) by determining their circulatory concentrations in patients with MM and healthy controls and correlated observations with grade and severity of the disease. The study group consisted of 112 subjects: 62 patients with MM and 50 healthy controls. Regarding serum levels of Th1 cytokines, IFN-gamma was significantly lower and IL-2 was non-significantly increased, while regarding levels of Th2 cytokines, IL-4 and IL-10 were significantly elevated. Results of our study indicate that a marked polarization exists toward Th2 cytokines in MM while Th1 cytokines remain suppressed.

Mollaret meningitis may be caused by reactivation of latent cerebral toxoplasmosis

Mollaret meningitis (MM) occurs mainly in females and is characterized by recurrent episodes of headache, transient neurological abnormalities, and the cerebrospinal fluid containing mononuclear cells. HSV-2 was usually identified as the causative agent. Recently, we found that recurrent headaches in non-HIV-infected subjects were due to acquired cerebral toxoplasmosis (CT). The aim of the study was therefore to focus on molecular pathomechanisms that may lead to reactivation of latent CT and manifest as MM. Literature data cited in this work were selected to illustrate that various factors may affect latent CNS Toxoplasma gondii infection/inflammation intensity and/or host defense mechanisms, i.e., the production of NO, cytokines, tryptophan degradation by indoleamine 2,3-dioxygenase, mechanisms mediated by an IFN-gamma responsive gene family, limiting the availability of intracellular iron to T. gondii, and production of reactive oxygen/nitrogen species, finally inducing choroid plexitis and/or vasculitis. Examples of triggers revealing MM and accompanying disturbances of IFN-gamma-mediated immune responses that control HSV-2 and T. gondii include: female predominance (female mice are more susceptible to T. gondii infection than males); HSV-2 infection (increased IFN-gamma, IL-12); metaraminol (increased plasma catecholamine levels, changes in cytokine expression favoring T(H)2 cells responses); probably cholesterol contained in debris from ruptured epidermoid cysts (decreased NO; increased TNF-alpha, IL-6, IL-8). These irregularities induced by the triggers may be responsible for reactivation of latent CT and development of MM. Thus, subjects with MM should have test(s) for T. gondii infection performed obligatorily.

Allogeneic CD3/CD28 cross-linked Th1 memory cells provide potent adjuvant effects for active immunotherapy of leukemia/lymphoma

The breaking of peripheral T-cell tolerance toward self-antigens expressed by tumor cells and the subsequent establishment of an effective tumor protective immune response remains a major challenge for cancer immunotherapy. We report that both protective and therapeutic anti-tumor immune responses can be achieved in a mouse leukemia/lymphoma tumor model through the strong adjuvant effects provided by allogeneic CD3/CD28 cross-linked Th1 memory cells. The adjuvant effect of these cells is mediated by their ability to produce a variety of 'danger signals' which serve to deviate native non-protective Th2 anti-leukemia immune responses to effective Th1 immune responses.

Diabetic ketoacidosis during therapy for pediatric acute lymphoblastic leukemia

BACKGROUND

Hyperglycemia is common during therapy for acute lymphoblastic leukemia (ALL), but diabetic ketoacidosis (DKA) occurs rarely. Morbidity due to DKA in children with ALL has not been systematically studied.

PROCEDURES

We reviewed risk factors and clinical consequences of DKA in patients undergoing therapy for ALL at SJCRH between 1991 and 2006.

RESULTS

DKA occurred in 6 of 797 evaluable patients. Only older age at diagnosis of ALL was a risk factor for DKA. Four of six patients with DKA as compared to 232 of the other 791 patients were older than 10 years (P = 0.03). Race, sex, body mass index, leukemia immunophenotype, ALL risk category, white blood cell count at diagnosis, and treatment protocol were not associated with DKA. All patients were managed with intravenous fluids, dietary modification, and short-term use of insulin. Patients were hospitalized for 4-12 days, with a median ICU stay of 1 day. In two patients, correction of hyperglycemia was too rapid, and two others experienced hypoglycemia due to insulin therapy. There were no permanent complications of DKA or its treatment. No patient required long-term insulin use. No patient had recurrent DKA; only one of the six patients had a subsequent hyperglycemia episode. All six patients are alive in remission 6-13 years after diagnosis.

CONCLUSIONS

Patients with hyperglycemia during treatment for ALL should be screened for clinical evidence of DKA, which may require more intensive supportive care than those without ketoacidosis. The occurrence of DKA should not lead to alteration of ALL treatment.

Cytokines and other immunological biomarkers in children's environmental health studies

Environmental exposures (e.g. pesticides, air pollution, and environmental tobacco smoke) during prenatal and early postnatal development have been linked to a growing number of childhood diseases including allergic disorders and leukemia. Because the immune response plays a critical role in each of these diseases, it is important to study the effects of toxicants on the developing immune system. Children's unique susceptibility to environmental toxicants has become an important focus of the field of immunotoxicology and the use of immune biomarkers in molecular epidemiology of children's environmental health is a rapidly expanding field of research. In this review, we discuss how markers of immune status and immunotoxicity are being applied to pediatric studies, with a specific focus on the various methods used to analyze T-helper-1/2 (Th1/Th2) cytokine profiles. Furthermore, we review recent data on the effects of children's environmental exposures to volatile organic compounds, metals, and pesticides on Th1/Th2 cytokine profiles and the associations of Th1/Th2 profiles with adverse health outcomes such as pediatric respiratory diseases, allergies, cancer and diabetes. Although cytokine profiles are increasingly used in children's studies, there is still a need to acquire distribution data for different ages and ethnic groups of healthy children. These data will contribute to the validation and standardization of cytokine biomarkers for future studies. Application of immunological markers in epidemiological studies will improve the understanding of mechanisms that underlie associations between environmental exposures and immune-mediated disorders.

Acute lymphoblastic leukaemia cells express CCR7 but not higher amounts of IL-10 after CD40 ligation

OBJECTIVE

Production of cytokines that support T-cell activation and proliferation and migration to lymph nodes is one of the most important terms of cancer vaccine development. In previous studies we and others used CD40 ligation to obtain higher expression of co-stimulatory and adhesion molecules on leukaemic cells from children with acute lymphoblastic leukaemia (ALL). This time we assess the cytokine and chemokine gene expression profile in CD40-stimulated ALL cells.

MATERIAL AND METHODS

Malignant cells from 25 children with BCP-ALL were stimulated (or not) with huCD40LT and rIL-4 for 96 h. Eleven different molecule, cytokine and chemokine mRNAs levels (CCR7, IL-23, TGF-beta-IP, IFN-gamma, IL-10, CD1a, CD40, CD54, CD80, CD83, CD86) were determined using the real-time PCR technique with TaqMan chemistry using ready-to-use low-density arrays for gene expression by Applied Biosystems.

RESULTS

1) Increases in mRNA levels for CD40, CD54 and CD80 after CD40L and IL-4 stimulation were observed, 2) CCR7 mRNA expression was higher after CD40 ligation than before the culture (p = 0.002), 3) IL-10 mRNA expression was higher after the culture with medium than before the culture (p = 0.01).

CONCLUSIONS

The results show that leukaemia-derived dendritic cells obtained with CD40 ligation express CCR7 - chemokine is involved in migration to lymph nodes and does not produce higher amounts of IL-10, a potent immunosuppressive cytokine. Our preclinical findings could be used in the design of immunotherapy trials for the treatment of children with ALL.

Current concepts of tumor-infiltrating lymphocytes in human malignancies

Tumor-infiltrating lymphocytes (TILs) develop as manifestations of the recognition and defense against malignant cells by the host immune system. TILs were literally defined as "tumor-infiltrating lymphocytes", which a posteriori locate within the tumor tissues. Although such cells can be found, they fail to control the growth of tumor. Many have proposed diverse mechanisms for dysfunction of TILs with regard to the roles of immunosurveillance against cancer. However, only a few cancer types, e.g. melanoma, have seen the benefits brought by activating these cells for immunotherapy. Functional defects of TILs have been linked to abnormalities of signaling molecules; however, there is conflicting data. The death of TILs was attributed to expression of cancer-derived FasL, PD-1 and RCAS1, and cancer-induced activation-induced cell death (AICD). Confirmed by studies using TILs and animal models, the compromise of tumor-specific immune responses was thought to result from not only mechanisms of clonal anergy but also exhaustion and/or deletion. Furthermore, functional cytotoxic CD8(+) TILs might be rendered incompetent by cancer-induced up-regulation of inhibitory NK receptors or proximal signaling abnormalities. Additionally, immune privilege was partly attributed to recruitment of regulatory T cells to the tumor sites. The failure of IL-2 signaling, which stands at the center of T cell functionalities, had been linked to the enzymatic activity of cancer-derived matrix metalloproteinases (MMPs). Finally, the exploitation of IDO expression, an important enzyme in pregnancy-related immunosuppression, by cancer cells might play a role in tumor immunity. The disparity of cancer types, origin, developmental stages and individual genetic backgrounds likely account for differences, or even contradictions, which might be the reason why immunotherapy works only on a few cancer types. Delineating the mechanisms behind functional defects of TILs can help not only boost chances of the development of a successful cure but understand the not fully identified roles played by immune system in the face of malignancies.

Immune dysfunction and micrometastases in women with breast cancer

Cytokines produced by T lymphocytes are critical to the efficacy of a given immune response and dysregulation of immune responses may play a role in cancer progression. We assessed the intracellular cytokine profiles of T cells in the peripheral blood of women with breast cancer and explored the relationship of these responses with the presence of cancer in lymph nodes and bone marrow. Peripheral blood lymphocytes from 84 patients and 26 healthy volunteers were analyzed by 4-color flow cytometry for surface markers and for intracellular cytokines. Bone marrow samples from some of these patients were also collected and analyzed for the presence of epithelial cells (micrometastases) by flow cytometry. The percentages of both CD4(+) and CD8(+) cells producing type1 (IL-2, IFN-gamma or TNF-alpha) and type 2 (IL-4) were significantly lower in patients with breast cancer compared to healthy controls. These results indicate a general immune dysfunction in these patients as opposed to a shift in the balance of type1 and type2 cells. These dysregulated T cell responses did not correlate with age, stage of disease, or nodal status. However, we did observe a correlation between number of micrometastases in the bone marrow and T cell responsiveness.

High Th1/Th2 ratio in patients with multiple myeloma

To determine the clinical significance of the T helper 1(Th1)/T helper 2 (Th2) ratio in multiple myeloma, the intracellular IFN-gamma and IL-4 were analyzed by flow cytometry in 56 patients with multiple myeloma. The mean Th1/Th2 ratio of cases in the initial diagnosis phase and the refractory phase were higher than that of the control group. The mean serum beta-2-microglobulin in the high Th1/Th2 subgroup was significantly higher than that in the normal Th1/Th2 subgroup (P < 0.05). In conclusion, the Th1/Th2 ratio was closely related to the disease status of multiple myeloma.

CpG stimulation of precursor B-lineage acute lymphoblastic leukemia induces a distinct change in costimulatory molecule expression and shifts allogeneic T cells toward a Th1 response

Immunostimulatory DNA containing unmethylated cytosine-phosphate-guanosine (CpG) induces the development of T helper 1 (Th1) immune responses. The response of B cells to CpG stimulation involves increased proliferation, cytokine production, and costimulatory molecule expression. Similar effects have been observed following CpG stimulation of a variety of malignant B cells. Pediatric precursor B acute lymphoblastic leukemia (B-ALL) cells express low levels of costimulatory molecules and are generally poor stimulators of T-cell responses. In this study, we evaluated the impact of CpG stimulation on precursor B-ALL cell lines and pediatric patient-derived samples. The ability to respond to CpG oligodeoxynucleotides was determined by the level of Toll-like receptor 9 (TLR9) expression. In contrast to both nonleukemic B-cell precursors and mature B cells, the response of precursor B-ALL cells was characterized by increased CD40 expression but only small changes in CD86 levels and no induction of CD80 expression. CpG stimulation of ALL blasts produced increased levels of interleukin-6 (IL-6), IL-8, and IL-10 but no detectable IL-12p70 and led to a skewing of allogeneic T cells, with enhanced interferon gamma (IFN-gamma) production and reduced secretion of IL-5. These results demonstrate the functional relevance of CpG stimulation of precursor B-ALL cells and provide a rational basis for study of these agents for use in treatment of this disease.

Flow Cytometric Detection of Intracellular Th1/Th2 Cytokines Using Whole Blood: Validation of Immunologic Biomarker for Use in Epidemiologic Studies

Few biological markers of immune function have been thoroughly validated for use in epidemiologic studies that involve delayed sample processing and analysis. Here, we report our validation results for flow cytometric detection of intracellular T-helper 1/T-helper 2 (Th1/Th2) cytokines using 500 μL of whole blood obtained from children and adults. The detection of Th1/Th2 cytokine profiles by flow cytometry is a practical and mechanistically relevant assay because dysregulated cytokine production has been observed in many immune-mediated disorders, including cancer. We evaluated the intraassay and intraindividual and interindividual variability and the effects of a 24- to 72-hour delayed analysis on Th1 and Th2 end points. We compared the distributions of %CD4 lymphocytes, %Th1, and %Th2 in young children (age 1 year, n = 50) and adults (age 25–52 years, n = 16). Subjects sampled monthly for up to 1 year showed minimal variation in CD4, Th1, and Th2 end points. Delayed analysis of samples (up to 24 hours) resulted in no significant differences in the expression of CD4, Th1, and Th2; however, at 48 and 72 hours, all end points differed significantly from baseline (P &lt; 0.01). A random effects model confirmed that interindividual variability was much greater than intraindividual variability for CD4 and Th1. Compared with adults, children had marginally higher %CD4, similar %Th2, but significantly lower %Th1 (P &lt; 0.01). These results show that flow cytometric detection of CD4, Th1, and Th2 markers using whole blood is reproducible and that these biomarkers can be effectively used in human population studies that involve transported samples, delayed processing and analysis, and limited blood volumes.

Th1/Th2 cells in patients with multiple myeloma

Multiple myeloma (MM) is a lymphoproliferative disorder that is characterized by a proliferation of clonal B cells in various stages of maturation that then infiltrate the bone marrow. MM has been reported to accompany various T cell abnormalities including quantitative and functional defects of CD4+ and CD8+ T cells. Recently, immunotherapy such as dendritic cell therapy, vaccination therapy, and anti-tumor antibody therapy, has been attempted in patients with MM. To develop more effective immunotherapy for patients with MM, further studies are required to identify the immunological abnormalities, especially in T cells, associated with MM. The T helper 1 (Th1) and T helper 2 (Th2) cells are characterized by distinct cytokine production patterns. The Th1 cells produce interferon gamma and interleukin-2 (IL-2), and are involved in cell-mediated immunity. The Th2 cells produce IL-4 and promote humoral immunity by stimulating antibody production, particularly IgE responses. Furthermore, Th1 and Th2 cells have been found to cross-regulate each other's development. The Th1/Th2 combination has an important role in immune response to many disorders including infection, autoimmune diseases, and malignancies. In this review, we report a Th1/Th2 imbalance in cases of MM, and discuss the relationship between T cell abnormalities and the pathology of MM.

Altered patterns of T cell cytokine production induced by relapsed pre-B ALL cells

Relapse of pediatric acute lymphoblastic leukemia (ALL) remains a significant clinical problem. The graft-versus-leukemia (GVL) effect after hematopoietic stem cell transplantation indicates that immune mechanisms may play a role in the control of ALL blasts. In this study, we analyzed primary diagnostic and relapsed pre-B ALL samples for the surface expression of several molecules implicated in immune responses and for the induction of allogeneic T cell responses. There were no significant differences in the expression of CD11a, CD40, CD80 and CD86 or MHC classes I and II molecules between the diagnostic and relapsed samples. We found no significant differences in the overall ability of diagnostic and relapsed pre-B ALL samples to induce T cell proliferation and cytokine production. However, in the case of T cell responses induced by diagnostic ALL samples, there was excellent correlation between proliferation and production of all cytokines analyzed. In the case of relapsed samples, the only correlation obtained was with IL-5. This observation indicates that the nature of the immune response generated by relapsed ALL cells in an allogeneic setting differs from that obtained with diagnostic samples, suggests a biasing towards a Th2 response may contribute to the evasion of effective immune responses by relapsed ALL.

Quantification and cytokine production of circulating lymphoid and myeloid cells in acute myelogenous leukaemia

A simple assay was developed to assess the potential of patients with acute myelogenous leukaemia (AML) to respond to immunotherapy. Lymphocytes, monocytes and leukaemic blasts with their corresponding intracellular cytokine profiles were evaluated by four-colour flow cytometry. In 50 microl samples of whole blood, surface labelling for CD45, CD8 and CD3 was used for cell identification prior to intracellular staining for interleukin (IL)-4, IL-10, IL-12 and interferon (IFN)-gamma. Absolute numbers of CD8(+) and CD8(-) (putative CD4(+)) T-cells, NK cells (CD8(+)/CD3(-)) and monocytes were determined by reference to a fixed number of added fluorescent beads. The absolute numbers of CD8(-) and CD8(+) T-cells in the blood of patients with AML were similar to those of normal controls. More of the lymphocytes in the blood of leukaemic patients spontaneously produced cytokines compared with those of controls. Furthermore, primary AML blasts secreted predominantly IFN-gamma. After recovery from chemotherapy, lymphocyte counts tended to be lower than in normals and reduction of NK cells reached significance after the second chemotherapy (P=0.01). A prominent CD8(lo)/CD3(lo-int) lymphocyte subset appeared after recovery in some patients. This laboratory application of the study of cell subsets and intracellular cytokines in patients undergoing treatment may be helpful in monitoring immunological responses in AML.

Co-expression of CD30 ligand and interleukin 4 (IL-4) receptors by acute myeloid leukaemia blasts is associated with the expansion of IL-4-producing CD30+ normal T cells

CD30 ligand (CD30L), but not its cognate receptor CD30, is frequently expressed on acute myeloid leukaemia (AML) blasts. In the present study, we found that leukaemic blasts presenting surface CD30L displayed a characteristic cytokine-receptor pattern that makes them ideal targets for those cytokines usually produced by Th2-type cell subsets. In particular, even though a broad distribution of Th2 cytokine receptors by AML blasts was shown, we demonstrated the almost exclusive expression of interleukin 4 (IL-4) receptor (R), in the absence of its cognate cytokine, by CD30L+ AML. Furthermore, a number of Th2-associated markers, including CD30, IL-4 and GATA-3, were expressed by residual T cells derived from CD30L+ AML but not from CD30L- AML, in which the presence of the Th1-associated marker LAG-3 was documented in some cases. The production of IL-4 in the absence of interferon gamma (IFN-gamma) was also detected in CD3+/CD30+ T cells from CD30L+ AML. These results, along with the shift toward IL-4-producing specific T-cell clones observed in CD30L+ AML samples by enzyme-linked Immunospot (ELISpot) assay, were consistent with the hypothesis of a Th2 polarization taking place in T cells from CD30L+ AML. The notion that IL-4 was able to enhance in vitro proliferation of CD30L+/IL-4R+ purified leukaemic blasts suggests that the selective interaction of IL-4-producing CD30+ T cells with CD30L+ leukaemic progenitors may have a role in the progression of this particular AML subset.

Decreased production of interleukin-12 and type 2 immune responses are marked in cachectic patients with colorectal and gastric cancer

Balance of the two types of T helper cells is one of the most important factors for regulation of the immune system. This study examines the production of interleukin (IL)-4, -6, -10, -12, and interferon-gamma by peripheral blood mononuclear cells stimulated with phytohemagglutinin or Staphylococcus aureus. Sixty-one patients, including 25 with gastric and 39 with colorectal cancer, and 39 normal volunteers were entered. The production of IL-12 decreased significantly with advancing disease and was lowest in the patients with distant metastases and cachexia. Compared with normal donors, the production of interferon-gamma decreased in all categories of patients, with no difference among patient groups. Levels of Th2 cytokines, such as IL-4, IL-6, and IL-10, also showed no difference among patient groups. However, production of all these cytokines had increased by 2.5 months after sequential testing in the same cachectic patients. The authors' findings indicate that the induction of Th1 cells seems to be suppressed at a relatively early stage of disease, whereas that of Th2 cells seems to increase in the terminal stage.

The Th1-Th2 classification of cellular immune responses: concepts, current thinking and applications in haematological malignancy

The finding that T cell immune responses could be divided into those promoting cell mediated immunity (Th1) and humoral responses (Th2) has had a profound effect on the understanding of immune response generation over the last 15 years. With ever increasing knowledge of the immune system, the model has come under criticism, as not all responses easily fit the classification. Nonetheless, the model still provides a valuable framework on which to base immunological research. In this review we update the model with current thinking regarding the generation and maintenance of immune responses. We then examine how the Th1-Th2 paradigm may be applied in developing new understanding of several topical issues in haematological malignancy-control of graft-versus-host disease; cytokine control of proliferating clones in B and T cell diseases; and suppression of T cell responses in multiple myeloma.