Correlation of serum IL-2, IL-6 and IL-10 levels with International Prognostic Index in patients with aggressive non-Hodgkin's lymphoma

Attenuated adiponectin, omentin, increased interleukin-6 and tumor necrosis factor-alpha levels with altered cognition and depression in non-Hodgkin lymphoma patients: A case-control study

BACKGROUND AND PURPOSE

Immune dysfunction is one of the risk factors which plays an important role in the development of non-Hodgkin lymphoma (NHL), and inflammation may be involved in its etiology. Minimal data is available on the effect of cytokine levels on neurobehavioral function in lymphoma before the initiation of chemotherapy. Therefore, we aimed to explore the risk of NHL by assessment of cytokine and adipokine levels and their correlation with neurobehavioral changes.

METHODS

This case-control study enrolled 62 subjects (age-sex matched: 31 cases and 31 controls). Neurobehavioral assessment was done using Montreal Cognitive Assessment questionnaire (MoCA) and Patient Health Questionnaire (PHQ-9). EORTC Core Quality of Life questionnaire (EORTC QLQ-C30) was used to assess quality of life. Questionnaire assessment and sample collection were done after the patient enrolment and before first cycle of chemotherapy.

RESULTS

Mean age of NHL patients and healthy controls was 51.9 ± 11.8 and 50 ± 10.9 years, respectively. NHL patients showed significantly higher levels of IL-6 (0.77 ± 0.11) and TNF- α (1.47 ± 1.31) than controls (0.55 ± 0.4 and 0.66 ± 0.89, respectively) with p-value<0.005. Also, NHL patients showed significantly lower levels of adiponectin (0.31 ± 0.24) and omentin (0.46 ± 0.1) than controls (0.42 ± 0.13 and 0.53 ± 0.11, respectively) with p-value<0.005. Lower MoCA and EORTC QLQ C-30 scores and higher PHQ-9 scores were observed in NHL patients in comparison to healthy control.

CONCLUSION

Our results showed that adiponectin, omentin IL-6 and TNF-α may be used as pre-diagnostic markers of NHL risk. Neurobehavioral changes observed in NHL patients may alter the quality of life.

Assessment and prognostic significance of a serum cytokine panel in diffuse large B‑cell lymphoma

The objective of the present study was to assess the levels of circulating cytokines in patients with diffuse large B-cell lymphoma (DLBCL), and to examine the associations between the cytokine levels, clinicopathological manifestations and patient prognosis. The study enrolled 49 patients with DLBCL, 11 patients with chronic lymphocytic leukemia/small lymphocytic lymphoma and 67 healthy controls from Zhejiang Provincial People's Hospital (Hangzhou, China) between January 2017 and January 2020. The serum levels of interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were measured using flow cytometry. The IL-6, IL-10 and IFN-γ levels were significantly raised in patients with DLBCL compared with those in the healthy controls (P<0.05). The levels of IL-10 were significantly higher in patients with raised levels of circulating lactate dehydrogenase (P<0.05), while increases in both IL-6 and IL-10 were associated with raised C-reactive protein (CRP) levels, with IL-6 levels positively associated with those of serum CRP (P<0.01; r=0.66). Additionally, International Prognostic Index (IPI) risk stratification of patients with DLBCL was strongly associated with circulating IL-6 and IL-10 levels. Raised IL-6, IL-10 and TNF-α levels were linked with worse short-term treatment efficacies (P<0.05). Moreover, the accuracy of the model predicting short-term treatment response in patients with DLBCL, obtained using the support vector machine algorithm, was 81.63%. It was also found that raised serum IL-6 and IL-10 levels, together with reduced levels of IL-17, were associated with survival of <1 year in patients with DLBCL (P<0.05), although no significant link was found between cytokine levels and long-term overall survival. In conclusion, the serum levels of IL-6, IL-10, IL-17, TNF-α and IFN-γ can potentially serve as biological indicators of DLBCL tumor immune status, and combined application with the IPI score can be a robust prognostic indicator in patients with DLBCL.

Cytokine profiles in patients with newly diagnosed diffuse large B-cell lymphoma: IL-6 and IL-10 levels are associated with adverse clinical features and poor outcomes

BACKGROUND

The development of diffuse large B-cell lymphoma (DLBCL), a prevalent subgroup of non-Hodgkin lymphoma (NHL), potentially involves various cytokines. We aimed to determine the correlation between deregulated serum levels of cytokines and clinical features and investigate their impact on the prognosis of patients with DLBCL.

METHODS

We conducted a retrospective study of 77 patients with newly diagnosed DLBCL to explore the relationships between different cytokines, adverse clinical features, and poor outcomes. The Mann-Whitney U test was used to compare the cytokine profiles between patients with DLBCL and healthy controls. The Kaplan-Meier method was used to analyze the probability of survival, and the log-rank tests were used to evaluate the differences between survival curves. The Cox proportional hazards regression model was used to performed univariate and multivariate analyses to evaluate prognostic variables for survival analyze.

RESULTS

Serum levels of interleukin-2 (IL-2), tumor necrosis factor (TNF)-α, IL-6, IL-10, and IFN-γ were significantly elevated in patients with untreated DLBCL. Serum levels of IL-6 and IL-10 were significantly higher in patients with an International Prognostic Index (IPI) of 3-5, bone marrow involvement, serum levels of LDH ≥ 250 U/L, and β2-microglobulin (β2-MG) levels ≥ 2.3 mg/L. Patients with B symptoms only had higher serum IL-10 levels, whereas patients with a partial response or no response to treatment had significantly elevated serum levels of IL-6 as well as IL-10. Significant positive correlations were observed between the levels of IL-6 and IL-10 with those of β2-MG and LDH. Patients with levels of IL-6 ≥ 4.5 or IL-10 ≥ 5.0 pg/mL, as well as combined elevated IL-6 and IL-10 levels, exhibited shorter progression-free survival and overall survival. Additionally, univariate and multivariate analyses revealed that serum levels of IL-6 ≥ 4.5 pg/mL and IL-10 ≥ 5.0 pg/mL and IPI 3-5 were independent prognostic factors for relapse and survival in patients with DLBCL.

CONCLUSIONS

Pre-treatment serum IL-6 and IL-10 levels in patients with newly diagnosed DLBCL might be powerful markers for determining treatment response and predicting the prognosis of DLBCL.

Serum IL-6, IL-8, IL-10 and Beta2-Microglobulin in Association with International Prognostic Index in Diffuse Large B Cell Lymphoma

Aims and Background

Diffuse large B-cell lymphoma displays striking heterogeneity at clinical, genetic and molecular levels. The International Prognostic Index is useful to predict the outcome of diffuse large B-cell lymphoma patients. However, patients with identical International Prognostic Index values in clinical practice exhibit marked variability in survival, suggesting the presence of significant residual heterogeneity within each category. Since cytokines such as interleukin-6, -8 and -10 play important roles in the pathogenesis of lymphomas, and plasma level of beta2-microglobulin is associated with the outcome of patients with diffuse large B-cell lymphoma, the aim of the present study was to determine whether these parameters combined with the International Prognostic Index would better stratify these patients to predict their prognosis.

Patients and Methods

The study included 46 untreated diffuse large B-cell lymphoma patients.

Results

All study parameters (International Prognostic Index, Ann Arbor stage, extra-nodal involvement, performance status, lactate dehydrogenase, beta2-microglobulin, interleukin-6 and -10, and response to therapy) except for patient age and serum interleukin-8 level were associated with overall survival. In addition, the International Prognostic Index was strongly correlated with beta2-microglobulin, interleukin-6, -8 and -10, and when combined these parameters significantly better stratified patients according to survival. On multivariate analysis, therapeutic response to the primary treatment, elevated interleukin-6 and -10 levels, and the International Prognostic Index were significant predictors of overall survival.

Conclusions

Our data imply that interleukins and beta2-microglobulin evaluation should be used in association with the International Prognostic Index to define prognostic subgroups in diffuse large B-cell lymphoma patients.

The protein Z/protein Z-dependent protease inhibitor complex

Protein Z (PZ) is a vitamin K-dependent factor identified in human plasma in 1984 but it has no enzymatic activity. It is a cofactor of a serpin, the protein Z-dependent protease inhibitor (ZPI), and the complex PZ/ZPI inhibits activated factor X on phospholipid surfaces. In mice, the disruption of PZ or ZPI gene is asymptomatic, but enhances the thrombotic phenotype and mortality of other thrombotic risk factors. Most of the clinical studies focused on PZ. Despite conflicting results, a recent meta-analysis indicated that PZ deficiency could be a risk for venous and arterial thrombosis and early fetal loss. However, these conclusions are drawn from case-control studies of small size, constituting an important limitation. Recently, it was shown that PZ and/or ZPI are synthesised by normal kidney and different cancer cells, suggesting that the complex PZ/ZPI could play a role in inhibiting the tissue deposition of fibrin. The physiopathological consequences of these observations remain to be established. At this time, the measurement of plasma PZ and ZPI or analysis of their gene polymorphisms should not be performed routinely for the exploration of thrombophilia.

Comparison of serum cytokine levels between dogs with multicentric lymphoma and healthy dogs

In humans, multiple cytokines have been linked to the development of lymphoma, and are relevant biomarkers for response to chemotherapy and prognosis. In contrast, only a few circulating cytokines have been studied in dogs with lymphoma. We prospectively enrolled thirty-one dogs newly diagnosed with multicentric lymphoma. Immunophenotype was determined by flow cytometry in all dogs, separating them into 2 subgroups: B cell lymphoma (n=21) and T cell lymphoma (n=10). Nineteen healthy dogs were enrolled in the control group. Circulating cytokine concentrations were measured using a commercial canine multiplex magnetic bead-based assay which included Interleukin-2 (IL-2), IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF), Tumor Necrosis Factor-α (TNF-α), Interferon γ (IFN-γ), IFN-γ induced Protein-10 (IP-10), Keratinocyte Chemoattractant-like (KC-like), and Monocyte Chemoattractant Protein-1 (MCP-1). The serum levels of each cytokine were first compared between the lymphoma and control groups, and then between the B cell lymphoma, T cell lymphoma, and control groups. There was no significant difference between the lymphoma and healthy control groups regarding sex, age and weight. MCP-1, IL-6, and IL-10 were significantly higher in dogs with lymphoma compared to healthy dogs (p<0.01, p=0.01 and p=0.03, respectively). MCP-1 and IL-10 were significantly higher in the B cell lymphoma group than in the healthy group (p=0.01, p=0.01, respectively). MCP-1 and IL-6 levels were significantly higher in the T cell lymphoma group than in the healthy group (p=0.02, p<0.01, respectively). IL-6 was significantly higher in the T cell lymphoma group than in the B cell lymphoma group (p=0.03). Significant differences among the groups were found for IL-15 and KC-like, but they were affected by age and/or sex. There were no significant differences in serum IL-2, IL-7, IL-8, IL-18, GM-CSF, TNF-α, IFN-γ, and IP-10 between any of the groups. Significant differences in red blood cell, white blood cell, neutrophil, lymphocyte and monocyte counts were also found between the different groups of dogs. Our data showed different serum cytokine and peripheral blood cell profiles between dogs with lymphoma and healthy dogs, and between dogs with B cell and T cell lymphoma. Further study is necessary to investigate the role of these cytokines in lymphoma pathogenesis, response to treatment, and prognosis, and the influence of age, sex and blood cell counts on their expression.

Are the high serum interleukin-6 and vascular endothelial growth factor levels useful prognostic markers in aggressive non-hodgkin lymphoma patients?

Objective:

Pro-inflammatory and pro-angiogenic cytokines play an important role in the pathogenesis of lymphoma, and recent studies have shown that cytokines can be used as prognostic markers. Non-Hodgkin lymphoma (NHL) patients with high levels of serum interleukin-6 (s-IL6) and serum vascular endothelial growth factor (s-VEGF) have poor prognosis and shorter survival time. We aimed to determine pre-treatment levels of s-IL6 and s-VEGF and their relation with known prognostic markers, especially International Prognostic Index (IPI) scores, and to examine their effects on overall survival in newly diagnosed, untreated aggressive NHL patients.

Materials and Methods:

The study included 51 newly diagnosed NHL patients and 17 healthy controls. Blood samples were obtained to study s-IL6 and s-VEGF cytokine levels.

Results:

Patients with aggressive NHL diagnosis had higher s-VEGF and s-IL6 levels than the healthy population. If the s-IL6 levels of patients were above the cut-off levels, the overall survival time was shorter. There was no relation between s-VEGF and overall survival time.

Conclusion:

s-IL6 is an independent prognostic factor that may be included in IPI risk classification. In addition to the s-IL6 level, age, erythrocyte sedimentation rate, beta-2 microglobulin, WHO performance status, and IPI score are independent prognostic factors that are effective, especially for overall survival, in the clinical follow-up of NHL patients.

Immune function in newly diagnosed children with malignancy

BACKGROUND

Tumor genesis of many pediatric malignancies remains unclear. Data of immune function are lacking at diagnosis. We prospectively analyzed 109 pediatric patients with malignancy at diagnosis.

METHODS

Lymphocyte subpopulations were characterized by FACS, TREC-assay, and Immunoscope, cytokines by FACS and ELISA.

OBSERVATIONS

We detected higher values of CD4(+) T cells and consecutively shifted CD4(+)/CD8(+) ratio in all patients compared with the control group. In patients with lymphoma, interleukin-2 was upregulated in all subpopulations.

CONCLUSIONS

On the basis of these findings an altered immune function could be found in children with different malignancies at diagnosis. Further investigations are necessary to identify tumor-related immune deficiency for novel therapeutic approaches.

Tissue expression of interleukin 2 (IL-2) and IL-2 receptor (IL-2R(alpha)/CD25) in non-Hodgkin B-cell lymphomas in children: correlations with clinical data

The study aimed at analysis of tissue expression of interleukin 2 (IL-2) and subunit alpha of its receptor (IL-22R(alpha)/CD25) in B-cell non-Hodgkin lymphomas (B-cell NHLs) in children as related to selected clinical data. The studies were performed on an archival tissue material originating from children with B-cell NHLs (n=26) using avidin-biotin-peroxidase complex method and in-situ hybridization with biotinylated tyramine amplification signal (ImmunoMax technique). As compared with non-neoplastic lesions, in B-cell NHLs a significantly higher expression was noted of both IL-2 and IL-22R(alpha). In children with B-cell NHLs, frequency of IL-2 detection was 62%, and that of IL-22R(alpha), 46%. Using hybridocytochemistry, presence of mRNA for IL-2 could be detected, but not mRNA for IL-22R(alpha) in children with B-cell NHLs. A significant direct relationship was demonstrated between expressions of IL-2 and IL-22R(alpha) in children with B-cell NHLs. No significant relationships could be detected between expression of IL-2 and/or IL-22R(alpha) on one hand and histopathologic diagnosis, tumor location, age, or sex in B-cell NHLs on the other. The new element in the results involved demonstration of significant differences in shorter survival of children with B-cell NHLs, as related to cellular expression of IL-2 and IL-22R(alpha) (CD25). Comparing the expected percentage of patients at risk, children with CD25-positive tissue expression had a significantly lower chance to survive longer time than children with IL-2-positive tissue expression. The positive relationship between tissue expression of IL-22R(alpha) and the shorter survival of children with B-cell NHLs should prompt further investigations to identify other risk factors in patients with this type of tumors in children.

Pre-treatment serum levels of interleukin-10, interleukin-12 and their ratio predict response to therapy and probability of event-free and overall survival in childhood soft tissue sarcomas, Hodgkin's lymphomas and acute lymphoblastic leukemias

OBJECTIVES

Deregulated serum IL-10, IL-12 and their reciprocal balance have been stated in malignancies of adults. In children with cancer the issue has not been investigated so far.

DESIGN AND METHODS

To determine the diagnostic and prognostic roles of pre-treatment serum levels of IL-10 (Th2 cytokine), IL-12 (Th1) and their ratios (measured by the IL-10 and IL-12p70 ELISA kits; Endogen) in 91 children with soft tissue sarcomas (STS), Hodgkin's lymphomas (HL) and acute lymphoblastic leukemias (ALL).

RESULTS

Median IL-10 and IL-12 levels were significantly higher in cancer patients than in healthy controls. Increased IL-10 indicated presence of general symptoms in HL and high risk group in ALL. Elevated IL-10 and IL-10/IL-12 ratios and decreased IL-12 correlated with poor-risk histology in STS, poor response to therapy, relapse and death from cancer. Multivariate analysis identified IL-10/IL-12 ratio>0.14 and IL-12<40 pg/mL as significant predictors for shorter EFS and OS, respectively.

CONCLUSION

Pre-treatment serum levels of IL-10, IL-12 and IL-10/IL-12 balance in children with STS, HL and ALL may be of value as additional prognostic tools to predict the response to therapy and probability of EFS and OS.

Interaction between BCL2 and interleukin-10 gene polymorphisms alter outcomes of diffuse large B-cell lymphoma following rituximab plus CHOP chemotherapy

PURPOSE

Rituximab may overcome bcl-2-mediated chemoresistance through the inhibition of interleukin-10 (IL-10)-mediated loops, thus down-regulating bcl-2 expression. We examined the effects of genetic variation in BCL2/IL10 gene loops on treatment outcomes of diffuse large B-cell lymphoma when treated with either CHOP or rituximab plus CHOP (R-CHOP) chemotherapy.

EXPERIMENTAL DESIGN

Four genotypes were tested including BCL2 -938 C>A (rs2279115), +21 A>G (rs1801018), IL10 -819 T>C (rs1800871), and -592 A>C (rs1800872) in patients receiving either R-CHOP (n = 125) or CHOP (n = 110).

RESULTS

IL10 SNPs, -819 TT/TC or -592 AA/AC genotypes correlated with improved CHOP response rates (P = 0.04). Neither polymorphism separately influenced the failure-free survival (FFS) or overall survival in patients, but the IL10 haplotype was associated with treatment outcomes after R-CHOP for FFS (P = 0.03) or progression (P = 0.007), whereas the -938 AA BCL2 genotype significantly affected overall survival (P = 0.04). An interactive effect between BCL2 and IL10 SNPs was significant in the group with both -938 AA BCL2 genotype and 1 to 2 copies of CC IL10 haplotype. This group showed a better FFS (P = 0.01) and a lower probability of progression (P = 0.004) compared with other genotype groups when treated with R-CHOP chemotherapy.

CONCLUSIONS

These data indicated that R-CHOP chemotherapy resistance in diffuse large B-cell lymphoma may involve interactions between the BCL2 and IL10 genes.

Prognostic value of serum soluble interleukin-2 receptor level in patients with diffuse large B cell lymphoma, treated with CHOP- or RCHOP-based therapy

The emergence of rituximab has changed the clinical outcome of patients with B-cell lymphoma, which necessitates reassessment of previously determined prognostic factors. Thus, we evaluated the prognostic significance of serum soluble interleukin-2 receptor (sIL2R) levels in patients with diffuse large B cell lymphoma (DLBCL), treated with CHOP (n = 108) or RCHOP (n = 94). Serum sIL2R level ranged from 316 to 23 800 U/mL (median 1064 U/mL) and levels were generally higher in higher IPI risk group. Multivariate analyses revealed that sIL2R > or =1000 U/mL was associated with shorter progression free survival [hazard ratio (HR) = 2.52, p = 0.011] and overall survival (HR = 2.34, p = 0.037) independent of IPI risk group or rituximab use. Further subgroup analyses revealed that the impact of sIL2R was most apparent in patients with IPI low risk, both in CHOP alone and RCHOP group. Our study confirmed the prognostic value of sIL2R in patients with DLBCL with low International Prognostic Index (IPI) risk, also in the era of rituximab.

Aggressive non-Hodgkin's lymphoma: concomitant evaluation of interleukin-2, soluble interleukin-2 receptor, interleukin-4, interleukin-6, interleukin-10 and correlation with outcome

The purpose of this study was to assess the prognostic value of a large panel of cytokines in aggressive non-Hodgkin's lymphoma (NHL) and to confront it to parameters of the International Prognostic Index (IPI). It investigated the concomitant determination of interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R), interleukin-4 (IL-4), interleukin-6 (IL-6) and interleukin-10 (IL-10) on a uniform population of 116 previously untreated patients. Commercially available enzyme-linked immunoassay kits were used for cytokines measurements. Results were correlated with complete remission (CR), overall survival (OS) and failure free survival (FFS). In univariate analysis, sIL-2R and IL-6 demonstrated prognostic significance for CR (p = 0.016 and p = 0.048), OS (p = 0.0011 and p = 0.0387) and FFS (p = 0.0001 and p = 0.0363), but multi-variate analysis failed to demonstrate an independent prognostic significance. In the intermediate group risk defined by IPI, patients presenting high level of sIL-2R or IL-6 demonstrated lower CR rate and survival than those with low level. In conclusion, sIL-2R and IL-6 serum levels are elevated in high grade NHL and are correlated to CR, OS and FFS, but this study did not support their independent prognostic value. However, sIL-2R and IL-6 measurements may improve risk assignment by IPI and allow a better prognostic evaluation of patients with intermediate prognosis NHL.

Interleukin-10 gene polymorphism influences the prognosis of T-cell non-Hodgkin lymphomas

Interleukin-10 (IL-10) is one of the cytokines implicated in the pathogenesis of diffuse large B-cell lymphoma (DLBCL) in which it acts as auto/paracrine growth factor for lymphoma growth. T-cell non-Hodgkin lymphoma (NHL) is a heterogeneous disease, the biological basis of which is not fully understood. Some evidence suggests that IL-10 might be associated with the progression of T-cell NHLs and that IL-10 may be involved in a rescue effect, protecting T cells from apoptotic cell death associated with upregulated bcl-2 expression. The current study evaluated the impact of IL-10 gene (IL10) polymorphism on the response to chemotherapy and survival in T-cell NHL. IL10 polymorphisms were determined in 108 patients with T-cell NHL. The response to chemotherapy was not dependent on IL10 polymorphism, while survival differed significantly according to IL10 polymorphism. The group with ATA haplotype showed superior overall survival (61.2 +/- 5.9% vs. 21.2 +/- 11.7%, P = 0.001) and failure-free survival (35.0 +/- 5.7% vs. 13.2 +/- 8.7%, P = 0.001) compared to those without ATA haplotype. The ATA haplotype was identified as a favourable prognostic factor compared to non-ATA haplotype (P = 0.037, hazard ratio 2.1), together with international prognostic index (IPI) in a multivariate model for overall survival. In conclusion, IL10 polymorphism may affect the survival of T-cell NHL patients.

Early changes in serum IL-6 and VEGF levels predict clinical outcome following first-line therapy in aggressive non-Hodgkin's lymphoma

Inflammatory cytokines play important roles in the pathogenesis of lymphomas and may reflect underlying biological processes including tumour-host interactions with prognostic information that is not afforded by conventional clinical parameters. Several lines of evidence suggest that serum levels of interleukin (IL)-6 and vascular endothelial growth factor (VEGF) are independent indicators of long-term outcome in non-Hodgkin's lymphoma (NHL), but the clinical impact of early serial monitoring of these cytokines has not been reported. Serum samples from 64 newly diagnosed patients with aggressive NHL were obtained before the first cycle of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) and then weekly until the second cycle was given. Serum IL-6 and VEGF were measured by commercial enzyme-linked immunosorbent assays (ELISA). Pre-treatment serum IL-6 and VEGF levels were significantly correlated to response rate and overall survival. A significant decrease of IL-6 and VEGF levels was observed in the first weeks after CHOP therapy in patients achieving a complete remission after treatment. Multivariate analysis indicated that early changes of IL-6 and VEGF serum levels within the first 3 weeks after initiation of chemotherapy were independent predictors of clinical response even when corrected for the influence of clinical prognostic factors. Only changes in serum IL-6 level had borderline significance for the prediction of overall survival. The data indicate that serial measurements of serum IL-6 and VEGF may be early prognostic indicators and support the hypothesis of a clinical impact by early recognition of poor-risk patients and candidates for new treatment options.

Functional analysis of -571 IL-10 promoter polymorphism reveals a repressor element controlled by sp1

Transcriptional dysregulation of the IL-10 gene may contribute to the development and severity of autoimmune, infectious, neoplastic, and allergic diseases. A C to A base substitution has been identified at -571 bp in the IL-10 promoter and has been linked to immune diseases. The role of this polymorphism in IL-10 promoter function was assessed using luciferase reporter constructs. The presence of an A at -571 (A allele) increases promoter activity compared with that of a promoter with a C at this position (C allele). Binding of nuclear extract proteins from IL-10-producing human cell lines to DNA sequences including this base exchange and flanking sequences was demonstrated using EMSAs. Specific binding of the transcription factors Sp1 and Sp3 was demonstrated to a region immediately upstream of the polymorphism. No differences in the binding affinity of recombinant Sp1 were observed between the two forms of the promoter. Reconstitution of Sp1 expression decreased IL-10 promoter function in an Sp1-deficient cell line, demonstrating that this element functions as a repressor. The C to A base exchange relieves the repression mediated by Sp1. Individuals carrying the A allele of the IL-10 promoter may display increased synthesis of IL-10, resulting in suppressed immune responses and a modulation of their susceptibility to autoimmune, infectious, neoplastic, or atopic disease.

Studies in NZB IL-10 knockout mice of the requirement of IL-10 for progression of B-cell lymphoma

NZB mice develop an age-related malignant expansion of a subset of B cells, B-1 cells, with autocrine production of IL-10. IL-10, a pleiotropic cytokine with anti-inflammatory properties, is a potent growth and survival factor for malignant B cells. To further examine the in vivo requirement for IL-10 in the development and expansion of malignant B-1 clones in NZB mice, we developed a strain of homozygous IL-10 knockout (KO) mice on an NZB background. The NZB IL-10 KO mice develop peritoneal B-1 cells with approximately the same frequency as heterozygous and wild-type littermates. In contrast, the development of malignant B-1 cells in the peripheral blood and spleen, observed in wild-type NZB, rarely occurred in the NZB IL-10 KO. Phenotypic analysis of surface marker expression in splenic B cells indicated that, in contrast to the NZB with malignant B-1 splenic lymphoma, the surface marker expression of NZB IL-10 KO splenic B cells indicated that the majority of the B cells were typical B-2 cells. In the absence of IL-10, spontaneously activated B cells and antiapoptotic gene expression were reduced and lymphoma incidence was decreased. These results indicate that IL-10 is a critical factor for the progression of this B-cell malignant disease.

Interleukin-10 concentration determined by sandwich enzyme-linked immunosorbent assay is unrepresentative of bioactivity in murine blood

Two experiments were performed, each using six male and six female C57BL/6J mice collectively ranging from 4 wk to 17 mo of age. Blood was obtained following CO2 anesthesia, and the IL-10 concentration of each serum sample was determined both by sandwich enzyme-linked immunosorbent assay (ELISA) and by bioassay. In the first experiment, mean serum IL-10 immunoactivity was 9.3 pg/ml while the mean bioactivity was 700 times greater, i.e., 6.5 ng/ml. However, the bioassay required sample dilution, which might have released bound cytokine that the ELISA could also detect. In the second experiment, therefore, the ELISA was applied to samples diluted to 20% as for the bioassay. Nevertheless, the immunoassay continued to detect only a small fraction of the serum IL-10 identified by the bioassay (mean values: 32.4 pg/ml vs. 2.6 ng/ml). Although currently the preferred method, the sandwich ELISA is inappropriate for quantification of blood IL-10 concentrations. Moreover, studies of the actions of IL-10 are needed at the concentrations revealed in the blood by bioassay and currently considered supraphysiological.

Suppression of thymic lymphomas and increased nonthymic lymphomagenesis inTrp53-deficient mice lacking inducible nitric oxide synthase gene

Trp53-deficient mice spontaneously develop lymphomas, mainly of thymic origin, although the molecular mechanism remains largely unknown. As several interaction effects between p53 and iNOS have been reported, we hypothesized that iNOS activity in the thymus is causally linked to lymphomagenesis in Trp53-deficient mice. We therefore created mouse strains with different combinations of the Trp53 and iNOS genes. Western blot and histologic analyses showed that the iNOS protein was constitutively expressed in the thymus independently of Trp53 status and its expression was enhanced in Trp53+/- and Trp53-/- mice compared to Trp53+/+ mice. Homozygous disruption of iNOS decreased the incidence of thymic lymphomas by almost 40% (p=0.087) and 90% (p<0.05) in Trp53-/- and Trp53+/- mice, respectively, compared to the respective iNOS wild-type mice but significantly (p<0.05) increased the development of nonthymic lymphomas in Trp53-/- and Trp53+/- mice. Although iNOS gene disruption did not affect the phenotype of thymic lymphomas, absence of the iNOS gene shifted the spectrum of nonthymic lymphoma from the B-cell to the T-cell lineage. RT-PCR analysis revealed enhanced expression of IL-10, which could have a promoting effect on lymphomagenesis, even without any stimulation, in the spleen of aging mice with the gene combinations Trp53-/-iNOS-/- and Trp53+/-iNOS-/- but not Trp53-/-iNOS+/+ or Trp53+/-iNOS+/+. These results suggest that iNOS could increase the development of thymic lymphomas in Trp53-deficient mice. While iNOS may have protective effects against nonthymic lymphomagenesis, the regulation of cytokine production by iNOS may be involved in the underlying mechanism of antilymphomagenesis effects in the peripheral lymphoid organ.

Cytokines and antitumor immunity

Currently, the notion of immunosurveillance against tumors is enjoying something of a renaissance. Even if we still refuse to accept that tumors arising in the normal host are unable to trigger an immune response because of the lack of initiation ("danger") signals, there is no doubt that the immune system can be manipulated experimentally and by implication therapeutically to exert anti-tumor effects. For this activity to be successful, the appropriate cytokine milieu has to be provided, making cytokine manipulation central to immunotherapy. On the other hand, the major hurdle currently preventing successful immunotherapy is the ability of tumors to evolve resistant variants under the pressure of immune selection. Here, too, the cytokine milieu plays an essential role. The purpose of this brief review is to consider the current status of the application of cytokines in facilitating antitumor immunity, as well their role in inhibiting responses to tumors. Clearly, encouraging the former but preventing the latter will be the key to the effective clinical application of cancer immunotherapy.