Interleukin-10 reduces natural killer sensitivity and downregulates MHC class I expression on H-ras-transformed cells

Immune profiling after minimally invasive lobectomy

OBJECTIVES

Whether acute phase and immune responses are minimally affected following minimally invasive lung surgery needs further investigation. We performed a pilot study to evaluate the immune profile of patients who underwent video-assisted thoracoscopic surgery or robot-assisted thoracic surgery lobectomies for the treatment of suspicious or known stage I non-small-cell lung cancer.

METHODS

Blood samples were taken preoperatively and 3 and 24 h postoperatively were analysed for C-reactive protein, glucose, cortisol, tumour necrosis factor alpha (TNF-α), interleukin 8 (IL-8) and interleukin 10 (IL-10) levels. TNF-α, IL-8 and IL-10 were also measured in lung tissues. T (CD4, CD8), B (CD19) and natural killer (CD56, CD16) cell counts and natural killer cell functions were analysed using a flow cytometry-based assay before and after surgery.

RESULTS

Minimally invasive surgery (robot-assisted thoracic surgery + video-assisted thoracoscopic surgery) significantly decreased IL-10 (P = 0.016) levels after surgery. No significant differences were detected in TNF-α (P = 0.48) and IL-8 (P = 0.15) levels before and after surgery. C-reactive protein (P < 0.001), cortisol (P < 0.001) and glucose levels (P < 0.001) increased significantly after surgery. Lymphocyte, total T cell, CD3+CD4+ and CD3+CD8+ CD16+CD56+ cell counts were significantly lower on postoperative day 1.

CONCLUSION

There seems to be a dynamic balance between pro- and anti-inflammatory cytokines and immune cells following minimally invasive lobectomy.

Oncological advantage of nonintubated thoracic surgery: Better compliance of adjuvant treatment after lung lobectomy

BACKGROUND

Video-assisted thoracoscopic (VATS) surgery contributes to improved survival, adjuvant chemotherapy delivery and less postoperative complications. Nonintubated thoracic surgery (NITS) VATS procedures improves immunological responses in lung cancer patients; however, there is no data regarding adjuvant chemotherapy delivery effectiveness following NITS lobectomies. In this study, we aimed to compare protocol compliance and toxic complications during adjuvant chemotherapy after intubated and nonintubated VATS lobectomies in non-small cell lung cancer (NSCLC).

METHODS

We retrospectively reviewed the medical records of 66, stage IB-IIIB NSCLC patients who underwent intubated or nonintubated VATS lobectomy and received adjuvant chemotherapy.

RESULTS

A total of 38 patients (17 males, mean age 64 years) underwent conventional VATS and 28 (7 males; mean age 63 years) uniportal VATS NITS. Both groups had comparable demographic data, preoperative pulmonary function, and Eastern Cooperative Oncology Group (ECOG) status. Among the intubated and nonintubated patients, 82% and 75% were diagnosed with adenocarcinoma, respectively. The incidence of adenocarcinoma and squamous cell carcinoma cases were similar in both groups; however, the pathological staging showed significant differences, as 5 (18%) nonintubated patients had stage IB lung cancer, compared with the intubated group (P = 0.01). Further distribution of stages was similar between the groups. We observed significant differences in chest tube duration and operation time in the nonintubated group (P < 0.01). Among nonintubated patients, 92% completed the planned chemotherapy protocol, compared to 71% of the intubated group (P = 0.035). Grade 1/2 toxicity occurred significantly more often in the intubated group (16% vs. 0%, P = 0.03) and there was a lower incidence of grade 4 neutropenia in the nonintubated group (0% vs. 16%, P = 0.03).

CONCLUSIONS

Our results showed that the nonintubated procedure resulted in improved adjuvant chemotherapy compliance and lower toxicity rates after lobectomy.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Oncological advantage of the non-intubated thoracic surgery: better compliance with therapy protocol. What this study adds NITS lobectomies contribute to better administration of adjuvant chemotherapy with the planned cycle number and dosage.

Cytokine Gene Polymorphisms in Saudi Patients With Atopic Dermatitis: A Case-Control Study

The cause of atopic dermatitis (AD) is multifactorial and a number of genes including cytokines have been involved. We genotyped 315 subjects for polymorphisms in TNF-α and TNF-β and IL-10 genes. Patients had significantly higher frequency of GA genotype of TNF-α (−308 G/A) than healthy controls. Patients with AD and controls had similar distribution of A and G alleles. Genotype AA was found in 7.11% of controls while completely absent in cases. The frequencies of genotypes GG and AA of TNF-β (+252 A/G) polymorphism were higher whereas the frequency of genotype GA was significantly lower in patients than the controls. The frequencies of genotypes GG and AA of IL-10 (1082 G/A) polymorphism were significantly increased whereas genotype GA was decreased in patients than the controls. It is concluded that TNF-α (−308 G/A), TNF-β (+252 A/G), and IL-10 (−1082 G/A) polymorphisms are linked with the susceptibility of AD in Saudis and can be a risk factor.

Comparison of postoperative immune function in patients with thoracic esophageal cancer after video-assisted thoracoscopic surgery or conventional open esophagectomy

AIM

The aim of the study was to compare postoperative immune function in patients with thoracic esophageal cancer (EC) after video-assisted thoracoscopic surgery (VATS) or conventional open esophagectomy.

PATIENTS AND METHODS

Medical records were retrospectively analyzed for 228 patients with thoracic EC treated at a single hospital using VATS (n = 52) or conventional open esophagectomy (n = 176). Proportions of CD3(+), CD4(+), CD8(+), and natural kill (NK) cells, as well as the ratio of CD4(+) to CD8(+) cells, were measured in the two groups using flow cytometry on preoperative day (PrD) 1 and postoperative days (PoD) 1 and 7.

RESULTS

Proportions of CD3(+), CD4(+), and NK cells as well as the CD4+/CD8+ ratio decreased significantly from PrD1 to PoD1 in both the VATS and open esophagectomy groups. In the VATS group, these parameters had returned to preoperative levels (PrD1) by PoD7. These parameters in open esophagectomy group increased from PoD1 to PoD7 but also lowered significantly to PrD1 by PoD7. The proportion of CD8(+) cells was similar between the two groups at all time points tested.

CONCLUSION

Patients may experience less postoperative immune suppression after VATS than after conventional open esophagectomy, and they may recover preoperative immune function more quickly.

Genetic Variants of Interleukin-10 Gene Promoter are Associated with Schizophrenia in Saudi Patients: A Case-Control Study

BACKGROUND

Interleukin-10 (IL-10) gene is considered as a potential candidate gene in schizophrenia association studies. The polymorphisms on IL-10 gene have been reported to be linked with susceptibility to the development of schizophrenia within consistent results.

AIMS

The aim of this case-control study was to examine whether the -1082A/G, -819T/C, and -592A/C polymorphisms in IL-10 gene are implicated in schizophrenia development in the Saudi population.

MATERIALS AND METHODS

Molecular genotyping of IL-10 gene polymorphisms was performed to analyze the genotypes and alleles distribution of three single-nucleotide polymorphisms (SNPs) in patients (n = 181) and healthy individuals as control group (n = 211).

RESULTS

The frequencies of GA genotype at -1082, and CC genotype at positions -592 and -819 were significantly higher in schizophrenia patients compared to healthy subjects suggesting that GA, CC, and CC genotypes are susceptible to schizophrenia. The ACC haplotype known to be associated with intermediate production of IL-10 are more prevalent in our schizophrenia patients. On the other hand, genotypes -1082 GG, -819 CT, and -592 CA of IL-10 were more prevalent in healthy controls suggesting protective effects of GA, CT, and CA genotypes against schizophrenia. There was no significant association of IL-10 polymorphisms with sex or positive or negative symptoms of schizophrenia.

CONCLUSION

This study indicates that the IL-10 gene polymorphisms play a significant role in the etiology of schizophrenia in Saudi Arabians patients.

Impact of IL-10 (-1082) promoter-single nucleotide polymorphism on the outcome of hepatitis C virus genotype 4 infection

Immunoregulatory cytokines may influence the hepatitis C virus (HCV) infection outcome. This study aimed to determine the genotypic and allelic frequencies of the interleukin (IL)-10 (-1082) G/A polymorphism, and its association with chronicity or resolution of HCV genotype 4 infection in Egypt. The frequencies of different dimorphic polymorphisms based on single nucleotide substitution in chronic HCV patients (50) and resolved HCV patients (50) were: IL-10 (-1082) G/G 22 (44%) and 18 (36%), G/A 19 (38%) and 24 (48%), and A/A 9 (18%), and 8 (16%), respectively. In the sustained virologic response (SVR) (36) and spontaneously resolved subjects (14) groups, the frequencies were: IL-10 (-1082) G/G 11 (30.6%) and 7 (50%) G/A 18 (50%) and 6 (42.9%), A/A 7 (19.4%) and 1 (7.1%), respectively. An association between male gender and chronic hepatitis C outcome (P value 0.041) was found. However, no significant gender difference was found when we compared females versus males with elevated alanine transaminase (ALT) levels in the chronic HCV patient group (P value = 1).

CONCLUSION

No significant difference in the frequency of IL-10 single nucleotide polymorphism (SNP) at position 1082 was found between chronic and resolved HCV subjects.

Surgical trauma and immune functional changes following major lung resection

Video-assisted thoracic surgery (VATS) has evolved greatly over the last two decades. VATS major lung resection for early stage non-small cell lung carcinoma (NSCLC) has been shown to result in less postoperative pain, less pulmonary dysfunction postoperatively, shorter hospital stay, and better patient tolerance to adjuvant chemotherapy compared with patients who underwent thoracotomy. Several recent studies have even reported improved long-term survival in those who underwent VATS major lung resection for early stage NSCLC when compared with open technique. Interestingly, the immune status and autologous tumor killing ability of lung cancer patients have previously been associated with long-term survival. VATS major lung resection can result in an attenuated postoperative inflammatory response. Furthermore, the minimal invasive approach better preserve patients' postoperative immune function, leading to higher circulating natural killer and T cells numbers, T cell oxidative activity, and levels of immunochemokines such as insulin growth factor binding protein 3 following VATS compared with thoracotomy. Apart from host immunity, the angiogenic environment following surgery may also have a role in determining cancer recurrence and possibly survival. Whether differences in immunological and biochemical mediators contribute significantly towards improved clinical outcomes following VATS major lung resection for lung cancer remains to be further investigated. Future studies will also need to address whether the reduced access trauma from advanced thoracic surgical techniques, such as single-port VATS, can further attenuate the postoperative inflammatory response.

In vitro evidence of the presence of mesenchymal stromal cells in cervical cancer and their role in protecting cancer cells from cytotoxic T cell activity

Mesenchymal stromal cells (MSCs) have been isolated from different tumors and it has been suggested that they support tumor growth through immunosuppression processes that favor tumor cell evasion from the immune system. To date, however, the presence of MSCs in cervical cancer (CeCa) and their possible role in tumor growth remains unknown. Herein we report on the presence of MSCs in cervical tissue, both in normal conditions (NCx-MSCs) and in CeCa (CeCa-MSCs), and described several biological properties of such cells. Our study showed similar patterns of cell surface antigen expression, but distinct differentiation potentials, when we compared both cervical MSC populations to MSCs from normal bone marrow (BM-MSCs, the gold standard). Interestingly, CeCa-MSCs were negative for the presence of human papilloma virus, indicating that these cells are not infected by such a viral agent. Also, interestingly, and in contrast to NCx-MSCs, CeCa-MSCs induced significant downregulation of surface HLA class I molecules (HLA-A*0201) on CaSki cells and other CeCa cell lines. We further observed that CeCa-MSCs inhibited antigen-specific T cell recognition of CaSki cells by cytotoxic T lymphocytes (CTLs). HLA class I downregulation on CeCa cells correlated with the production of IL-10 in cell cocultures. Importantly, this cytokine strongly suppressed recognition of CeCa cells by CTLs. In summary, this study demonstrates the presence of MSCs in CeCa and suggests that tumor-derived MSCs may provide immune protection to tumor cells by inducing downregulation of HLA class I molecules. This mechanism may have important implications in tumor growth.

Effects of hepatitis C virus on cardiovascular risk in infected patients: a comparative study

The role of hepatitis C virus (HCV) in the pathogenesis of atherosclerosis and cardiovascular events is unclear. The aim of this study was to evaluate the direct effect of HCV on cardiovascular risk and correlate it with pro and anti-inflammatory cytokines in patients with HCV. HCV monoinfected patients, genotype 1, naive, non-obese (BMI<30) and non-diabetics were included and compared to controls (blood donors). Patients with prior diagnosis of cardiovascular diseases, hypertension, chronic renal failure, cancer and chronic use of lipid-lowering drugs or immunosuppressants were excluded. Age, BMI, systolic blood pressure (SBP) and diastolic (DBP), fasting glucose and lipid levels were determined. Serum cytokines (IL-6, IL-10 and TNF-α) and Framingham score were also evaluated. 62 HCV patients, 34 (54.8%) were males and none of them was smoking. The Framingham scores (median and 25th and 75th percentiles) were 12% (6.5-14%), showing an intermediate cardiovascular risk in patients with HCV. There was significant direct correlation between Framingham and total cholesterol (p=0.043) and DBP (p=0.007). HDL-C (p=0.002) was inversely correlated with the Framingham score. HCV patients had higher levels of proinflammatory cytokines (IL-6 and TNF-α) compared to controls (p<0.0001) and the relation of proinflammatory/anti-inflammatory TNF-α/IL10 and IL-6/IL10 were higher in HCV patients (p<0.01). The Framingham score was directly correlated to IL-6 and TNF-α, but differences were not statistically significant. Patients with HCV monoinfected, nonobese, naïve and non diabetic have an intermediate cardiovascular risk, as measured by the Framingham score and high levels of proinflammatory cytokines (IL-6 and TNF).

Impact of Video-Assisted Thoracoscopic Major Lung Resection on Immune Function

Video-assisted thoracoscopic major lung resection for early stage non-small-cell lung carcinoma has been associated with less postoperative pain, better preserved pulmonary function, shorter hospital stay, and enhanced tolerance of adjuvant chemotherapy compared to thoracotomy. Initial concerns regarding safety, oncological clearance, and cost effectiveness were unfounded. Several recent trials have reported improved long-term survival in patients with early stage non-small-cell lung carcinoma undergoing video-assisted thoracoscopic major lung resection, compared to the open technique, although there are inconsistencies. Interestingly, the immune status and autologous tumor killing ability of lung cancer patients have previously been associated with long-term survival. Video-assisted thoracoscopic lung resection results in an attenuated postoperative inflammatory response, but more importantly, it better preserves postoperative immune function. Circulating natural killer and T-cell numbers, T-cell oxidative activity, and levels of immunochemokines such as insulin growth factor binding protein-3 are higher after video-assisted thoracoscopic surgery than after thoracotomy. Recently, interest has developed in the role of the angiogenesis factor, vascular endothelial growth factor, after cancer surgery. Whether differences in immunological and biochemical mediators contribute towards improved long-term survival following video-assisted thoracoscopic major lung resection for cancer remains to be confirmed.

Immunological and mutagenic actions of ribavirin monotherapy preceding combination therapy with interferon for patients with chronic hepatitis C

Background

We aimed to investigate the effects of ribavirin on hepatitis C virus (HCV). Immunological and virological effects were analysed in patients undergoing treatment with ribavirin monotherapy prior to the initiation of combination therapy with interferon-α.

Methods

A total of 25 patients with chronic HCV infection were enrolled in this study. All patients received ribavirin for 4 weeks during monotherapy; subsequently, interferon-α2b was additionally given as combined therapy. Patients were divided into two groups according to virological response. A rapid viral responder (RVR) was defined as a patient in whom HCV RNA became undetectable within 4 weeks after combination therapy. The changes of the T-helper (Th)1/Th2 subset of peripheral blood CD4+ T-cells, serum cytokine levels and the alignment of the interferon sensitivity- determining region (ISDR) during ribavirin monotherapy were analysed by flow cytometry, ELISAs and sequencing methods.

Results

A total of 17 patients were classed as RVR. In the RVR group, the mean ±sd serum alanine aminotransferase levels significantly decreased (before treatment 103 ±92 IU/l and after treatment 57 ±46 IU/l; P<0.05) during ribavirin monotherapy. The mean ±sd Th1/Th2 ratio significantly increased (before treatment 13.9 ±5.1 and after treatment 16.7 ±6.2; P<0.05), but did not change in the non-RVR group. The levels of Th2 cytokines (interleukin-10 and soluble CD30) significantly decreased, especially in the RVR group. The mean ±sd mutation rates of ISDR at the nucleotide level increased in the RVR group (before treatment 2.6 ±0.9 sites/clone and after treatment 3.9 ±1.6 sites/clone; P<0.05), but did not change in the non-RVR group.

Conclusions

Ribavirin administration might increase the efficacy of interferon therapy for patients with chronic hepatitis C by stimulating the host immune system and promoting HCV gene mutation.

Effect of cytokine gene polymorphism on histological activity index, viral load and response to treatment in patients with chronic hepatitis C genotype 3

AIM

To investigate the association between cytokine gene polymorphism and disease status in chronic hepatitis C genotype 3 by liver biopsy, ALT, HCV RNA levels and response to treatment.

METHODS

Patients with chronic hepatitis C genotype 3 were analyzed for single nucleotide polymorphisms of interleukin (IL)-10, IL-1 beta, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) by polymerase chain reaction using sequence-specific oligonucleotide primers. Liver biopsies were assessed by modified histological activity index (HAI) scoring system using a scale of 0-18 for grading the necro-inflammatory activity and 0-6 for staging the fibrosis. HCV RNA levels were determined by bDNA assay. The patients were treated with interferon alpha and ribavirin for 6 mo. Sustained virological response was assessed 6 mo after the completion of the treatment.

RESULTS

Out of the 40 patients analyzed, 26 were males. Mean age was 40.5+/-12.5 years (range 18-65 years). The frequencies of different dimorphic polymorphisms based on single nucleotide substitution were as follows: IL-10-1082 G/A 85%, A/A 12.5%, G/G 2.5%; IL-10-819 A/C 87.5%, C/C 10%, A/A 2.5%; IL-10-592 C/A 72.5%, C/C 27.5%; IL-1 C 90%, U 10%; IFN-874 T/A 50%, T/T 27.5%, A/A 22.5%; TNF-308 A/G 95%, G/G 5%; TGF-10 T/C 52.5%, C/C 35%, T/T 12.5%. The mean grades of necro-inflammatory activity of different genotypes of IL-10 at promoter site -1082 were A/A = 3.6, A/G = 5.0, and G/G = 10.0 and the difference was significant (P = 0.029). The difference in the stage of disease at a scale of 0-6 was A/A 0.8, A/G 2.3, and G/G 4.0 (P = 0.079). The difference in the HAI seemed to be related to the presence of allele -1082G. For IL-10 -819 genotypes, mean scores of fibrosis were A/A = 6.0, A/C = 2.2, and C/C = 1.0 (P = 0.020) though the inflammatory activity was not much different. No significant differences in HAI were noted among polymorphisms of other cytokines. Moreover, ALT and HCV RNA levels were not significantly different among different cytokine polymorphisms. There was a significant correlation of HAI and HCV RNA levels with the duration of disease. TGFbeta -10 genotype CC patients had a better end of treatment response than those with other genotypes (P = 0.020). Sustained virological response to the treatment was not influenced by the cytokine polymorphism. No effect of other factors like viral load, degree of fibrosis, gender, steatosis, was observed on sustained virological response in this population infected with genotype 3.

CONCLUSION

There is no significant correlation between cytokine polymorphisms and HAI except for the polymorphisms of anti-inflammatory cytokine IL-10, which may influence hepatic inflammatory activity and fibrosis in patients with chronic hepatitis C genotype 3. Sustained virological response in this genotype does not seem to be influenced by cytokine gene polymorphisms.

Thoracotomy is associated with significantly more profound suppression in lymphocytes and natural killer cells than video-assisted thoracic surgery following major lung resections for cancer

Major surgery is immunosuppressive, and this could have an impact on postoperative tumor immunosurveillance and, therefore, long-term survival in cancer patients. Video-assisted thoracic surgery (VATS) lung resection is a new alternative surgical approach to thoracotomy for patients with early lung cancer. This is a pilot study to examine the postoperative changes in leukocytes, lymphocyte subsets, B cells, T cells, and natural killer (NK) cells in non-small-cell lung cancer (NSCLC) patients undergoing lung resection with VATS versus thoracotomy approaches. Twenty-one consecutive patients with resectable primary NSCLC were assigned to VATS or thoracotomy approach over a 3-month period. Blood samples were collected preoperatively and at postoperative days (POD) 1, 3, and 7 for flow cytometry determination of total leucocytes, B cells, NK cells, lymphocytes, total T cells, and T4 and T8 cell numbers. There were no demographic differences between the two groups. Compared with the preoperative values, significantly increased total white cell numbers were detected at POD 1, 3, and 7 in all patients. At POD 1, although T8 cells and NK cells were reduced in both groups, total T cell, T4 cell, and lymphocyte numbers were significantly reduced only in the thoracotomy group. At POD 7, NK cell numbers were significantly lower in the thoracotomy group than that in the VATS group. No significant intra- or intergroup differences were seen with B cells. No significant differences in survival or disease-free survival were found between the two groups. Thus, VATS major lung resection for NSCLC is associated with less, as well as quicker recovery from, postoperative immunosuppression compared with the thoracotomy approach. The clinical relevance of better preserved cellular immunity in the early postoperative period warrants confirmation from large randomized trials.

Hepatitis B core antigen stimulates interleukin-10 secretion by both T cells and monocytes from peripheral blood of patients with chronic hepatitis B virus infection

In chronic hepatitis B virus (HBV) infection, immune responses to hepatitis B core antigen (HBcAg) are weak. Interleukin (IL)-10 is a potent immunosuppressive cytokine which we reported recently to be secreted in response to HBcAg by peripheral blood mononuclear cells (PBMCs) from patients with chronic HBV infection or healthy controls. Using an enzyme-linked immunospot assay, we compared the ability of HBcAg to stimulate IL-10 production by PBMC with that of lipopolysaccharide (LPS), phytohaemagglutinin-P and hepatitis C virus-derived antigens in 16 patients with chronic HBV infection and six healthy controls. Frequencies of IL-10 spot-forming cells (SFC) in response to HBcAg were comparable to those obtained with LPS in patients with chronic HBV infection. Frequencies of IL-10 SFC in response to HBcAg or to LPS were significantly higher in patients with chronic HBV infection than in healthy controls. IL-10 SFC in response to HBcAg consisted of 26-35% T cells, 62-70% monocytes and less than 1% B cells in patients with chronic HBV infection. Only monocytes contributed to IL-10 production in controls. Frequencies of HBcAg stimulated IL-10 SFC representing T cells and monocytes were significantly higher in patients with elevated serum alanine aminotransferase (ALT) and detectable HBV DNA than in patients with normal ALT and undetectable HBV DNA. The potent ability of HBcAg to stimulate IL-10 production by PBMC may contribute importantly to immune tolerance toward HBV.

Carcinogenicity testing of IL-10: principles and practicalities

IL-10 is a cytokine with actions at many levels of the immune system. In the course of development of recombinant human IL-10 (rhuIL-10) as a potential treatment for a number of chronic diseases of man, the question 'What about its carcinogenicity testing?' was repeatedly asked, based on scientific evaluation by toxicologists, beliefs about regulatory requirements, and questions considered likely to be raised by physicians, patients, and lawyers. The feasibility of various approaches to the carcinogenicity testing of rhuIL-10 is critically discussed here as a contribution to rational consideration of the general need for and value of such testing, and its particular feasibility for a recombinant human protein with profound effects on the immune system. The physiological functions of IL-10 in man and rodents are reviewed in detail, as there are notable differences between species in its normal activities, followed by detailed evaluation of the potential procedures and practical problems of its carcinogenicity testing as a heterologous, immunogenic protein in rodents. The value of information that might be obtained from transgenic mice is also evaluated, and so are the results of studies exploring its actions on human tumour cell biopsies and rodent and human cell lines. It is concluded that despite the probable popular and regulatory expectations that carcinogenicity test results would be provided, all the physiological and pathological information reveals no indication that rhuIL-10 would pose a carcinogenic risk to humans on prolonged administration, and that it would not be feasible to undertake such experimentation. It is argued that in this, as in other instances, professional and popular expectations have run beyond practical feasibility or theoretical justification. Cautious and critical evaluation should be made every time shorter or longer term toxicity studies of any candidate drug are planned or even considered, especially if it is a recombinant protein, to decide on objective grounds whether the studies are really necessary and whether they can be done in a way that will give meaningful results that will help in risk assessment.

Interleukin-10, interleukin-6 and interferon-gamma gene polymorphisms in melanoma patients

The immune response against melanoma can be influenced by cytokines with potentially opposite effects on tumour cell growth, such as interleukin-10 (IL10), interleukin-6 (IL6) and interferon-gamma (IFNgamma). Our objective in this study was to investigate whether polymorphisms in the regulatory regions of IL10, IL6 and IFNgamma genes are associated with the development of primary cutaneous melanoma and/or the prognosis of this tumour. We studied genotypic variations at positions -1082, -819 and -592 in the IL10 promoter, -174 in the IL6 promoter and +874 in the IFNgamma intron 1 in 42 melanoma patients and 48 healthy controls. These two populations showed very similar genotypic frequencies for IL10, IL6 and IFNgamma gene polymorphisms. There was a significant increase in the prevalence of IL10 low expression genotypes, specially the ACC/ATA genotype, among patients with a poorer prognosis. In contrast, IL6 promoter and IFNgamma intron 1 gene polymorphisms did not correlate with melanoma prognosis. These data indicate that investigation of polymorphisms in the regulatory regions of IL10, IL6 and INFgamma genes does not seem to be useful for predicting the risk of development of primary cutaneous melanoma. However, IL10 low expression genotypes may be associated with a poorer outcome in melanoma patients.

Molecular cloning of rat NK target structure--the possibility of CD44 involvement in NK cell-mediated lysis

The nature of target molecules of natural killer (NK) cell-mediated lysis remains to be elucidated. As we previously reported, mAb 109 recognizes one of the tumor-associated antigens, designated as 109 antigen (Ag), expressed on the cell surface of rat fibrosarcomas W31 and W14, which are transformants of WFB (rat fetal fibroblast cell line) with H-ras oncogene. 109Ag was thought to be a target structure of NK cells since mAb 109 inhibited NK cell-mediated lysis against W31 and W14. Here, we demonstrate by molecular cloning that 109Ag is identical to rat CD44. Immunoprecipitation and immunoblotting studies also showed that mAb 109 and anti-rat CD44 mAb OX-50 recognize the same protein of W31 cell lysates with an 86 kDa molecular size. CD44 was suggested to be a target structure of NK cell-mediated lysis; however, rat CD44 cDNA transfection alone into CD44 null cell lines did not result in up-regulation of target cell susceptibility to NK cell-mediated lysis. Our results therefore indicated that CD44 may play a crucial role as one of the target structures in our rat fibrosarcoma system though the cell surface expression of CD44 alone does not affect NK susceptibility of the target cells.

Interleukin-10 reduces natural killer (NK) sensitivity of tumor cells by downregulating NK target structure expression

We examined the effect of exogenous IL-10 on the sensitivity of rat W14 and W31 tumor cells to natural killer (NK) cell-mediated cytotoxicity in relation to previously identified NK target structure (NKTS) expressed on these cells. We also examined the effect of endogenous interleukin-10 (IL-10) on rat IL-10 cDNA-introduced W31 cells (W31T-H, a high-IL-10-producer clone; W31T-L, a low-IL-10-producer clone). Both exogenous and endogenous IL-10 had no effect on the proliferative activity of these cells, but incubation of cells with recombinant human (rh) IL-10 resulted in a dose-dependent decrease in the expression of NKTS recognized by mAb 109. The expression level of NKTS on W31T-H cells was dramatically decreased compared with that on W31T-L cells and parental W31 cells. In addition, treatment of W31 cells with the culture supernatants of W31T-H cells could downregulate the expression of the NKTS. Moreover, NK sensitivity of W31T-H was suppressed down to a level equivalent to that of W31 cells pretreated with exogenous rhIL-10, and cytolysis could no longer be inhibited by mAb 109. We previously demonstrated that IL-10 downregulated MHC class I expression in this model. Nevertheless, NK susceptibility was also decreased. Taken together, these results suggest that the IL-10-mediated decrease in NKTS expression has a larger effect than decreased MHC class I expression on NK sensitivity. Thus, our data reveal a novel mechanism for an IL-10-mediated escape of tumor cells from host immune surveillance by downregulation of NKTS expression.

Depletion of IL-10- and TGF-β-Producing Regulatory γδ T Cells by Administering a Daunomycin-Conjugated Specific Monoclonal Antibody in Early Tumor Lesions Augments the Activity of CTLs and NK Cells

It has been demonstrated that γδ T cells accumulating in early tumor lesions and those purified from spleen cells of tumor-bearing mice attenuate the activity of CTLs and NK cells. We, therefore, investigated whether depletion of γδ T cells from early lesions of tumors results in restoration of CTL and NK cell activities and subsequent regression of tumors. A daunomycin-conjugated anti-γδTCR mAb UC7-13D5 (Dau-UC7) was prepared to efficiently deplete γδ T cells. An in vitro study revealed that Dau-UC7 specifically lysed γδTCR+ cells and effectively inhibited splenic γδ T cells from tumor-bearing mice to produce cytotoxic cell-suppressive factors. Furthermore, intralesional injections of Dau-UC7 at an early stage of tumor development led to augmentation of tumor-specific CTL as well as NK cell activities and to the resultant regression or growth inhibition of the tumors. On analysis of cytokine profile, γδ T cells transcribed mRNAs for IL-10 and TGF-β, but not IL-4 or IFN-γ, suggesting the T regulatory 1-like phenotype. Finally, a blocking study with mAbs showed that the inhibitory action of γδ T cells on CTLs and NK cells was at least partly mediated by IL-10 and TGF-β. These results clearly demonstrated the novel mechanism by which T regulatory 1-like γδ T cells suppress anti-tumor CTL and NK activities by their regulatory cytokines in early tumor formation.