Impaired cytokine production in whole blood cell cultures from patients with colorectal carcinomas as compared to benign colorectal tumors and controls

Vitamin E and immunity

Vitamin E is the most important chain-breaking, lipid-soluble antioxidant present in body tissues of all cells and is considered the first line of defense against lipid peroxidation and it is important for normal function of the immune cells. However, vitamin E deficiency is rare in well-nourished healthy subjects and is not a problem, even among people living on relatively poor diets, both T- and B-cell functions are impaired by vitamin E deficiency. While immune cells are particularly enriched in vitamin E because of their high polyunsaturated fatty acid content, this point puts them at especially high risk for oxidative damage. Besides its immunomodulatory effects, vitamin E also plays an important role in carcinogenesis with its antioxidant properties against cancer, and ischemic heart disease with limiting the progression of atherosclerosis. Supplementation of vitamin E significantly enhances both cell mediated and humoral immune functions in humans, especially in the elderly and animals.

The effect of colorectal cancer upon host peripheral immune cell function

OBJECTIVE

Colorectal cancer is immunogenic. However, it is also associated with suppression of host immunity. Identifying the mechanisms involved in immune suppression is necessary to develop future immunotherapeutic strategies. The aim of this study was to assess immune cell function in colorectal cancer patients.

METHOD

A total of 80 colorectal cancer patients (41 male) prior to treatment and 38 matched controls (21 male) were recruited. Venous blood samples were taken. White blood cell composition was determined using monoclonal antibodies. Levels of cytokines IFN-gamma, TNF-alpha, IL-2, IL-10, IL-4 and IL-6 were measured from the supernatants of activated peripheral blood mononuclear cells (PBMC) following thawing and re-suspension. Peripheral blood mononuclear proliferation was measured using 3H-Thymidine.

RESULTS

Stage I-III cancer patients had elevated percentages of CD8 T cell (P = 0.004) whilst stage IV patients had low total lymphocyte percentages (P = 0.016). Monocyte and NKT cell percentage decreased with advanced tumour stages (P = 0.013 and P = 0.038). Patients had lower PBMC proliferation and production of the TH1 cytokines (IFN-gamma and TNF-alpha) (P < 0.001) than that of the controls. IL-6 and IL-4 production were not significantly different. IFN-gamma and TNF-alpha concentrations reduced with tumour vascular invasion (P = 0.011 and P = 0.019).

CONCLUSION

Colorectal cancer induces an immunological response, shifting the cytokine balance. The most profound changes are seen once disease has spread systemically.

Depressed tumor necrosis factor alpha and interleukin-12p40 production by peripheral blood mononuclear cells of gastric cancer patients: Association with IL-1R-associated kinase-1 protein expression and disease stage

Our study investigated the ability of peripheral blood mononuclear cells (PBMCs) isolated from patients with different clinical stages of gastric cancer to produce proinflammatory (tumor necrosis factor alpha [TNFalpha], interleukin 12p40 [IL-12p40] and interleukin 6 [IL-6]) and antiinflammatory (interleukin-10 [IL-10]) cytokines after stimulation with lipopolysaccharide (LPS) or tumor cells, and its correlation with IL-1R-associated kinase-1 (IRAK-1) protein expression. The data showed that TNF production by tumor cell-stimulated PBMCs obtained from patients with advanced gastric cancer was significantly depressed in comparison to the control group. The response to LPS was less affected. IL-12p40 production was depressed in all stages of disease, while the release of IL-10 and IL-6 remained unchanged. Depressed tumor cell-induced TNF and IL-12p40 production was associated with diminished IRAK-1 protein expression in PBMC. These findings may suggest that in advanced gastric cancer (at least in some cancer patients) diminished IRAK-1 protein expression may be a novel mechanism responsible for or facilitating downregulation of innate immune response to tumor cells.

Immunology and immunotherapy of colorectal cancer

This review critically discusses data on immunology of colorectal cancer, starting from pathology and molecular biology, and then considering the molecular characterisation of colon cancer antigens and the clinical trials of immunotherapy. A careful evaluation of histopathological studies on intra-epithelial infiltration by T cells in primary tumours, together with the analysis of HLA expression by colorectal cancer cells, suggest that anti-tumour T cell immune responses may take place in vivo in those patients, influencing prognosis and shaping the tumour immunological profile. Moreover, the molecular characterisation of tumour antigens expressed by colorectal carcinomas, together with improved understanding of mechanisms of the immune response and more sensitive methods for the in vivo detection of T cell responses, are now allowing researchers to design new and more effective vaccination protocols, with encouraging preliminary results. By drawing together the experimental evidence from different research fields, this review provides support for the concept that colorectal carcinoma is immunogenic and may reasonably be considered as a target for immunotherapy, and attempts to address critical issues and envisage future developments in this challenging research field.

Lymphocyte-mediated liver injury in alcohol-related hepatitis

The pathogenesis of alcohol-related liver disease (ALD) remains inadequately explained. Increasing alcohol intake is associated with an increased risk of ALD, but many heavy drinkers develop no liver damage. An explanation for ALD susceptibility requires theories that extend beyond a biochemical understanding of alcohol metabolism. Several hepatic cell populations are involved in the pathogenesis of liver injury. The liver-associated lymphocyte (LAL) response to alcohol intake plus immune stimulation may determine susceptibility to liver damage. We have isolated rat LALs and demonstrated the following: (1) Liver-associated lymphocytes differ from the peripheral blood lymphocyte pool; the CD8:CD4 ratio is higher in the LAL population than in peripheral blood. (2) Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 production by these cells is suppressed by regular alcohol intake. (3) Tumor necrosis factor-alpha and interleukin-6 production by LALs is increased after parenteral administration of concanavalin A (Con A) and by Con A in in vitro LAL cultures obtained from healthy (control) and ethanol-consuming rats. (4) In vivo stimuli that lead to increased cytokine production by LALs lead, within 12-24 h, to increased hepatocyte necrosis [elevated alanine aminotransferase (ALT) levels] and apoptosis. (5) Liver-associated lymphocytes isolated from ethanol-consuming rats, transferred to non-ethanol-consuming rats, confer on the latter animals an ethanol-consuming response to Con A. (6) Cytokine release by LALs is quantitatively as significant as that from Kupffer cells after exposure to lipopolysaccharide. (7) In co-culture studies inhibition of TNF-alpha activity reduces hepatocyte apoptosis induced in the presence of activated LALs. (8) Finally, nuclear factor-kappa B inhibition decreases production of nitric oxide and TNF-alpha, with an associated reduction in hepatocyte apoptosis. In summary, our study findings support the suggestion that a role for LALs exists in the pathogenesis of alcohol and Con A-mediated liver disease.

Shift of the gastric T-cell response in gastric carcinoma

BACKGROUND AND AIMS

The etiology and pathophysiology of stomach carcinoma is complex, and the mechanism whereby H. pylori directly or indirectly induces carcinoma remains unclear. In this study, interleukin (IL)-8, IL-4 and interferon (IFN)-gamma were measured in the tissue culture supernatant of gastric organ cultures from subjects with chronic gastritis with or without H. pylori infection, and with or without gastric cancer and gastric dysplasia.

RESULTS

Interleukin-8 levels were higher in cancer- and H. pylori-infected gastritis subjects than in H. pylori-negative subjects (12.95 +/- 3.16, 10.48 +/- 1.55 and 4.49 +/- 1.28 ng/mL, respectively). Elevated levels of IFN-gamma were detected in both H. pylori-infected and non-infected subjects with uncomplicated gastritis (72.23 +/- 19.0 and 34.61 +/- 5.30 pg/mL) and in non-infected dysplasia subjects (88 +/- 20.5 pg/mL). Background levels of IL-4 (< or = 9.4 pg/mL) in uncomplicated gastritis subjects and relatively high levels of IL-4 in dysplasia subjects (25.8 +/- 7.3 pg/mL) were detected. In contrast, trace amounts of IFN-gamma (16.01 +/- 0.35 pg/mL) and high levels of IL-4 (42.81 +/- 8.49 pg/mL) in gastric biopsy culture supernatants were found in cancer subjects. Mucosal IL-4 levels (but not IL-8 levels) correlated with infection and mucosal anti-H. pylori immunoglobulin G antibody.

CONCLUSIONS

The significant differences between gastritis with and without cancer and dysplasia indicated a shift from a Th1 to a Th2 helper cell pattern of cytokine secretion. This study has identified a local mucosal defect in gastric cancer. The near absence of IFN-gamma production from the mucosa at the margins of the tumor may be a critical factor in promoting growth of neoplastic cells.

Reduction in cytokine production in colorectal cancer patients: association with stage and reversal by resection

The aim of this study was to assess monocyte/macrophage function, as defined by lipopolysaccharide (LPS)-induced production of tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and interferon (IFN)-gamma by stimulated whole blood cultures in patients with colorectal carcinoma before and after surgical resection. Forty colorectal cancer patients prior to surgery and 31 healthy controls were studied. Heparinized venous blood was taken from colorectal cancer patients prior to surgery and from healthy controls. Serial samples were obtained at least 3-6 weeks post-operatively. Blood was stimulated with LPS for 24 h and supernatants were assayed for TNF-alpha, IFN-gamma and IL-10 by enzyme-linked immunosorbent assay. LPS-induced production of TNF-alpha and of IFN-gamma was reduced in patients with colorectal carcinoma compared to controls (TNF-alpha, 11,269 pg/ml(-1) ¿12,598¿; IFN-gamma, 0.00 pg/ml(-1) ¿226¿; median ¿IQR¿) (TNF-alpha, 20,576 pg/m(-1) ¿11,637¿, P < 0.0001; IFN-gamma, 1,048 ¿2,428¿, P = 0.0051, Mann-Whitney U-test). Production in patients after surgery had increased (TNF-alpha: 17,620 pg/ml(-1) ¿7,986¿; IFN-gamma. 410 pg/ml(-1) ¿2,696¿; mean ¿s.d.¿) and were no longer significantly reduced when compared to controls (TNF-alpha, P = 0.28; IFN-gamma, P = 0.76). Production of TNF-alpha and IFN-gamma prior to surgery were reduced to a greater extent in patients with Dukes' stage C tumours compared to those with Dukes' stage A and B stage. There was no difference in IL-10 production between any group. Monocytes/macrophages from patients with colorectal carcinoma are refractory to LPS stimulation as reflected by reduction in TNF-alpha and IFN-gamma production and this is more pronounced in patients with advanced stage tumours. This suppression is not mediated by IL-10 and disappears following surgical resection of the tumour. This provides evidence for tumour induced suppression of immune function in patients with colorectal cancer and identifies a potential therapeutic avenue.

Modulations of the effector function and cytokine production of human lymphocytes by secreted factors derived from colorectal-carcinoma cells

We investigated the in vitro effects of factors secreted by 3 freshly explanted human colorectal-carcinoma (CRC) cell lines on lymphocyte proliferation, IL-2-receptor expression, LAK-cell generation and cytokine secretion. We found that the supernatants of all 3 CRC cell lines inhibited T-cell proliferation in a dose-dependent manner, due to the secretion of immunosuppressive factors (ISFs). In addition, the supernatants of 2 cell lines were able to inhibit LAK-cell generation and to depress IL-2R, but not HLA-DR expression, on PHA-activated T cells. Furthermore, the secretion of cytokines, i.e., IFN-gamma, IL-1beta, IL-2 and TNF-alpha, by peripheral-blood mononuclear cells (PBMC) was differently modulated by the tumor-cell supernatants, e.g., the production of IFN-gamma was reduced in normal PBMC stimulated with PHA. However, the effects induced by the supernatants were not identical: for example, factors from one CRC cell line (w25) influenced early and late events of T-cell activation and division, while 2 others (w19 and te6) contributed only to the inhibition of early events. Some biochemical properties of the ISFs were characterized. Our results suggest that colon-tumor cells can secrete ISFs, which may lead to the in vivo immunosuppression often observed in patients with these tumors.

Immunoprevention of cancer poses a challenge to pharmacological research

The evolving understanding of the molecular mechanisms of carcinogenesis establishes that the long latency period would offer numerous opportunities for intervention before the final step of fully developed malignancy has been reached. Immunoprevention of cancer may be a new approach to cancer control, by eliminating the cellular minimal deviations that are seen in the early phases of carcinogenesis. Available results of immunotherapy of preneoplastic lesions and data on anticarcinogenesis with immunoregulators in experimental models are in good accordance with theoretical expectations. However, clinical research on immunoregulators still focuses on the treatment of advanced cancer. The major problem hampering a wider application of immunoregulators in cancer prevention is the possibility of potential adverse effects, which are largely unknown. The promotion of future research in this area is essential. Moreover, the ethical issues of intervention trials in cancer must be discussed, by considering the potential psychological and social consequences.

Alterations in T cells of cancer-bearers: whence specificity?

T cells of tumor-bearing mice and cancer patients have been reported to have altered signal-transduction machinery. These alterations have been implicated in immunological suppression. Here, Daniel Levey and Pramod Srivastava critically examine the evidence for these alterations in the context of the tumor specificity of immunological unresponsiveness in tumor-bearing hosts.

Interferons in precancer and cancer prevention: where are we?

Clinical research on interferons (IFN) still focuses on the treatment of advanced cancer. The research strategy eventually must be reevaluated. The cellular minimal deviations that are seen in early phases of carcinogenesis might be the most rational target for immune interventions. That biologic response modifiers have considerable capacity to prevent induction and development of malignant neoplasias has been demonstrated in several animal systems. Even the few clinical studies available at present on the treatment of preneoplastic lesions with IFN have definitely shown more success than those involving treatment of advanced tumors. In addition, there is experimental evidence that IFN might be suitable candidates for immunoprevention. The major problems hampering a wider application of IFN in immunoprevention is that they cause adverse effects. Unfortunately, we do not know much about the specific mechanisms involved in the immune control of human tumor development during the initial and the latency phases of carcinogenesis. More research is needed in this area. In this article the state of the art of using IFN for treating preneoplastic lesions is reviewed, and also we report some of our experimental results on IFN and anticancerogenesis.

Immunosuppressive activity of sera from patients with colorectal and gynecological carcinomas as evaluated by impaired IFN-gamma, IL-1 alpha and TNF-alpha production of human peripheral mononuclear cells

The sera from patients with preoperative colorectal and gynecological carcinomas (ovarian and breast cancer) were investigated for their putative immunosuppressive activity (ISA). ISA was measured by determining the changes in the production of IFN-gamma, IL-1 alpha and TNF-alpha by human peripheral mononuclear cells (PBMC) from six normal donors. Phytohemagglutinin-stimulated PBMC were incubated with sera from patients with colorectal and gynecological carcinomas and healthy controls and in the 4-day post-inductional supernatants the cytokines were measured by an enzymoimmunological assay (ELISA). Sera from patients with carcinomas significantly decreased the IFN-gamma production as compared to the controls. In the cultures containing sera from patients with colorectal and ovarian but not breast carcinoma, significantly lower levels of IL-1 alpha and TNF-alpha were measured compared to the cultures with sera from healthy controls.

Cytokine production in whole blood cell cultures of patients undergoing therapy with biological response modifiers or 5-fluorouracil

We have measured the levels of interferon gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha), IL-1 beta, and IL-2 in the whole blood cell culture supernatants of 43 tumor patients undergoing a treatment with biological response modifiers or a conventional therapy with 5-fluorouracil and leucovorin. In the blood cell cultures of the 16 patients who received 5-fluorouracil and leucovorin IFN gamma levels decreased (P < or = 0.01) and TNF alpha levels rose (P < or = 0.05) during each therapy cycle. However, in the blood samples a declining number of total leukocytes and lymphocytes was measured (P < or = 0.05). Progressive disease could be correlated to a tendency towards lower IFN gamma levels in the pretherapeutic cultures of these patients. The second group analyzed consisted of 8 patients receiving a low-dose IL-1 beta therapy. In this group we found either an unchanged or an augmented IFN gamma production of the blood cells during treatment. In the group of 13 patients receiving low-dose recombinant IL-2 (< or = 4.5 x 10(6) IU m-2 day-1) significantly increasing IFN gamma levels were seen in the blood cell cultures during the therapy (P < or = 0.05), although total leukocyte counts decreased. In this group, 4 had stable disease for at least 2 months and 9 patients had tumor progression under therapy. In the cultures of the latter a tendency towards lower IFN gamma values was found. Finally, the cytokine production in the blood cell cultures of 6 patients receiving a combination therapy of IFN alpha and high-dose IL-2 was studied. During this therapy a dramatically reduced production not only of IFN gamma but also of all other measured cytokines was found. In this group all patients had tumor progression under therapy. It is concluded that the measurements of cytokine production in a reproducible whole blood culture system may be useful for monitoring immunological therapies and may help us to find out which doses of biological response modifiers have enhancing or suppressive effects on the functions of the immune cells.

Impaired cytokine production in whole blood cell cultures of patients with gynaecological carcinomas in different clinical stages

The production of the cytokines IFN-gamma, IL-1-alpha, IL-2 and TNF-alpha was investigated in mitogen-stimulated, whole blood cell culture from 239 untreated patients with primary gynaecological carcinomas (breast, cervix, ovary, endometrium), and 191 healthy female controls. The cytokines were measured in the 4-day post-induction supernatants by a sensitive enzymoimmunological assay. In the blood cell cultures of all four groups of cancer patients, significantly lower values of IFN-gamma (P < or = 0.001), IL-2 (P < or = 0.01) and IL-1 alpha (P < or = 0.01) were found as compared to the controls, although lymphocyte and monocyte counts were almost identical. Grouping the tumour patients into different clinical stages we could show in the four groups of carcinomas a gradual depression of the cytokine production according to growing tumour burden.

Impaired cytokine production in whole blood cell cultures of patients with urological carcinomas

The production of the cytokines interferon gamma (IFN gamma), interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha) was investigated in the mitogen-stimulated whole blood cell culture media from 51 patients with urinary bladder carcinomas, 52 patients with renal carcinomas, 31 patients with prostatic carcinomas and 360 healthy controls. The cytokines were measured 4 days after induction by a sensitive enzymo-immunological assay. In the blood cell culture supernatants of the patients with urinary bladder carcinomas significant lower levels of IFN gamma (P < or = 0.001), IL-2 (P < or = 0.01) and TNF alpha (P < or = 0.05) were found as compared to the controls. Blood cells of patients with renal carcinomas had lower production of IFN gamma (P < or = 0.01), IL-2 (P < or = 0.001) and IL-1 alpha (P < or = 0.01), whereas the values of the total group of patients with prostatic carcinomas were not significantly different from those of the controls. Lymphocyte and monocyte counts were almost identical in the control and all tumor patient groups. When the patients with renal carcinomas and prostatic carcinomas were analyzed according to their different clinical stages we could show a gradual depression of the IFN-gamma levels, which was related to tumor burden.

Cytokine Levels in Whole Blood Cell Cultures of Oral Contraceptive Users and Pregnant Women

The production of the cytokines IFN-gamma, IL-2, IL-1-alpha and TNF-alpha was investigated in the supernatants of mitogen-stimulated whole blood cell cultures from 52 oral contraceptive users, 33 pregnant women and 75 female controls. Cells from women taking oral contraceptives produced significantly less IFN-gamma (p≤0.05) and TNF-alpha (p≤0.05) compared to the controls. In the cultures of the pregnant women significantly lower levels of IFN-gamma (p≤0.01), IL-2 (p ≤0.001) and TNF-alpha (p≤0.01) were found than in those of the controls. Total and differential leukocyte counts were almost identical in all three groups of women. It is suggested, that lymphocyte and monocyte function as measured by cytokine production is altered in women taking oral contraceptives and in pregnant women.