Induction of soluble tumour necrosis factor receptors during treatment with interleukin-2

Inflammatory cytokines are associated with the development of symptom burden in patients with NSCLC undergoing concurrent chemoradiation therapy

Elevations in cancer treatment-induced circulating inflammatory cytokines may be partially responsible for the development of significant symptom burden (e.g., pain, fatigue, distress, disturbed sleep) during concurrent chemoradiation therapy (CXRT). Sixty-two patients undergoing CXRT for locally advanced non-small cell lung cancer (NSCLC) reported symptoms weekly for 15 weeks via the M. D. Anderson Symptom Inventory (MDASI). Serum inflammatory cytokines were assessed weekly during therapy via enzyme-linked immunosorbent assay. Dynamic changes in cytokines and associated symptom profiles were estimated using mixed-effect models. MDASI symptom severity increased gradually as CXRT dose accumulated and peaked at week 8. Serum concentrations of interleukin (IL)-6, IL-10, and serum soluble receptor 1 for tumor necrosis factor (sTNF-R1) increased significantly by week 8 (all p<.05). During CXRT, controlled for age, sex, race, body mass index, cancer recurrence, previous treatment status, total radiotherapy dose, and CXRT delivery technique, an increase in sTNF-R1 was significantly related to an increase in the mean score for all 15 MDASI symptoms (estimate, 1.74; SE, 0.69; p<.05) and to a larger radiation dose to normal lung volume (estimate, 1.77; SE, 0.71; p<.01); an increase in serum IL-6 was significantly related to increased mean severity for the five most severe symptoms (pain, fatigue, disturbed sleep, lack of appetite, sore throat) (estimate, 0.32; SE, 0.16; p<.05). These results suggest a role for over-expressed pro-inflammatory cytokines in significant worsening of symptoms in NSCLC patients undergoing CXRT, and warrant further study to identify biological targets for ameliorating treatment-related symptom burden.

Soluble tumor necrosis factor receptor type I enhances tumor development and persistence in vivo

Secretion of human soluble tumor necrosis factor receptor type I (sTNFRI) by the mouse fibrosarcoma cell line, L929, previously has been demonstrated to confer resistance to in vitro lysis by TNF and to LAK- and CTL-mediated cytolysis. These findings suggest that, in vivo, sTNFRI contributes to tumor survival by inhibiting these immunologic mechanisms. To evaluate this hypothesis, we compared the growth of sTNFRI-secreting L929 cells with that of the unmodified parental fibrosarcoma in an in vivo mouse transplantation model. Secretion of sTNFRI by L929 cells markedly enhanced their tumorigenicity and persistence in syngeneic recipients. This benefit was abrogated by sTNFRI-neutralizing antibodies induced by immunization prior to tumor challenge. These data demonstrate that sTNFRI directly influences tumor formation and persistence in vivo and suggest the selective removal and/or inactivation of sTNFRI as a promising new avenue for cancer immunotherapy.

Soluble tumor necrosis factor receptors in chronic hepatitis C: a correlation with histological fibrosis and activity

BACKGROUND/AIMS

Tumor necrosis factor-alpha (TNF) is a mediator of inflammation and cellular immune response. Soluble TNF receptors (sTNFR) sTNF-R55 and sTNF-R75, which compete with cellular receptors for the binding of TNF, have been detected at high levels in infectious diseases including human immunodeficiency virus and HBV infection. In order to investigate the activation of the TNF system in HCV infection, we have analyzed the balance between TNF and sTNF-R in 60 HCV-infected subjects according to their clinical, biological, virological and histological characteristics.

METHODS

Serum TNF, sTNF-R55 and sTNF-R75 levels were determined by ELISA before any therapy and were compared to a control group of 60 healthy subjects and a group of 34 HBV-infected patients.

RESULTS

Mean TNF levels were 50.5+/-4.5 pg/ml in HCV patients, and undetectable (<5 pg/ml) in the control subjects. sTNF-R55 and sTNF-R75 levels were significantly higher in HCV-infected patients than in the controls: 2.88+/-0.14 ng/ml vs. 1.30+/-0.05, (p = 0.0001), and 9.54+/-0.58 ng/ml vs. 4.19+/-016, (p = 0.0001), respectively. sTNF-R55 and TNF-alpha levels in HCV patients were not significantly different from levels in HBV patients. sTNF-R75 levels were slightly lower than in HBV patients (9.54+/-0.58 vs. 11.4+/-0.79 ng/ml, p = 0.03). In contrast to other infectious diseases, there was no correlation between levels of sTNF-R and TNF. sTNF-R75 but not TNF levels were correlated with aminotransferases levels (p = 0.0001 and p = 0.0015 for aspartate and alanine aminotransferase, respectively), while sTNF-R55 levels were significantly correlated only with aspartate aminotransferase levels (p = 0.003). sTNF-R75 levels were significantly correlated with the Metavir activity index (p = 0.01), and sTNF-R55 and sTNF-R75 levels were significantly higher in patients with vs. without cirrhosis (3.22+/-0.21 vs. 2.54+/-0.17 ng/ml (p<0.02) and 11.6+/-0.86 vs. 7.5+/-0.53 ng/ml (p<0.001), respectively). sTNF-R55, sTNF-R75 and TNF levels were not correlated with viral load, genotype or response to interferon therapy.

CONCLUSIONS

Levels of soluble TNF receptors, and particularly sTNF-R75, are significantly correlated with the severity of the disease but not with virological parameters such as quantitative viremia and genotype. High TNF-R production could thus suggest that HCV-related liver disease involves immunological mechanisms, including activation of the TNF system.

Multifaceted inhibition of anti-tumour immune mechanisms by soluble tumour necrosis factor receptor type I

Soluble tumour necrosis factor receptor type I (sTNFRI) is a potent inhibitor of TNF with the potential to suppress a variety of effector mechanisms important in tumour immunity. That sTNFRI influences tumour survival in vivo is suggested by results from human clinical trials of Ultrapheresis, an experimental extracorporeal treatment for cancer. While the considerable clinical benefit provided by Ultrapheresis is correlated with the removal of plasma sTNFRI, there is no direct evidence that sTNFRI inhibits immune mechanisms which mediate tumour cell elimination. To evaluate formally the ability of sTNFRI to inhibit these mechanisms, we have engineered sTNFRI production into the TNF-sensitive murine fibrosarcoma cell line, L929. Soluble TNFRI-secreting L929 cells display increased resistance to direct lysis by TNF, and to lysis by syngeneic lymphokine-activated killer cells and cytotoxic T cells. These findings confirm the suggestion that sTNFRI inhibits immunological mechanisms important in tumour cell eradication, and further support a role for sTNFRI in tumour survival in vivo. In addition, these observations suggest the development of methods for more specific removal and/or inactivation of sTNFRI as promising new avenues for cancer immunotherapy.

The potential biological and clinical significance of the soluble tumor necrosis factor receptors

The role of TNF receptors (TNF-Rs) is not limited to signal transduction but includes extracellular regulatory functions affecting systemic TNF bioavailability. This review summarizes the regulation of TNF-R shedding and its kinetics, the complex interaction between the soluble receptors and their ligand in vitro and in vivo, and the potential diagnostic, prognostic and therapeutic value of the soluble receptors in malignant, inflammatory, infectious and autoimmune disorders.

Tumour necrosis factor (TNF) soluble receptors in malignant melanoma: correlation with soluble ICAM-1 levels

It has been recently suggested that soluble tumour necrosis factor receptors (sTNF-Rs) may represent prognostic factors in cancer. In malignant melanoma, the intercellular adhesion molecule (ICAM-1) has been described as involved in progression of the disease and is upregulated by TNF alpha. We report in this study the serum concentrations of sTNF-R1 and sTNF-R2 in 32 patients with primary melanoma and in 21 patients with metastatic melanoma, in correlation with those of soluble ICAM-1 (sICAM-1). Significantly raised sTNF-R1 levels were detected only in patients with metastatic melanoma compared with normal controls (P < 0.002), whereas sTNF-R2 levels were increased both in primary and metastatic melanoma (P < 0.001). The ratio of type 2 to type 1 proteins increased in malignant melanoma compared with the controls but remained constant with the progression of the disease. A correlation between sTNF-Rs and sICAM-1 concentrations in patients' sera was observed in metastatic melanoma. The combined adverse effects of these soluble proteins on normal immune effector functions may contribute to tumour progression.

High plasma interleukin-2: a potential cause of insulin resistance

Low-density lipoproteins, infections and smoking are closely associated with insulin resistance. According to the hypothesis proposed in this paper, all of these factors could cause insulin resistance by the same mechanism. The first step in the cascade of events leading to insulin resistance is increased production of interleukin-2. This is followed by secretion of other cytokines, activation of macrophages and increased production of nitric oxide from L-arginine. The reduced amount of plasma L-arginine leads to decreased secretion of growth hormone and insulin-like growth factor-1 during exercise. The decreased secretion of insulin-like growth factor-1 is the basic reason for insulin resistance. Tumour necrotizing factor may also be involved in the pathogenesis of insulin resistance directly by binding in beta-adrenergic receptors. High plasma interleukin-2 also causes decreased bioavailability of insulin-like growth factor-1 by reducing the production of androgenic hormones.

Metastatic renal-cell carcinoma patients treated with interleukin 2 or interleukin 2 plus interferon gamma: immunological monitoring

We investigated the biological response of 73 patients with metastatic renal-cell carcinoma (MRCC) treated by repetitive weekly cycles of high-dose interleukin 2 (IL-2) (protocol 1, 40 patients) or IL-2 plus interferon-gamma (IFN-gamma) (protocol 2, 33 patients). The objectives of this study were (i) to evaluate the effects of this IL-2 administration schedule on biological response, (ii) to compare the effects of IL-2 alone with those of IL-2 plus IFN-gamma, (iii) to search for any correlation between certain biological marker values and the clinical response to treatment. Mean CD56+ lymphocyte counts (i.e., NK cells) were significantly higher than those of CD3+ cells in the 2 protocols and a subpopulation of CD56bright cells in protocol 1 was found to be preferentially expanded in vivo. Cytotoxic activity against K562 and Daudi cell lines as well as TNF-alpha and sTNF-alpha R (but not IL-6) significantly increased following treatment. Comparison of the data obtained from patients treated with IL-2 alone vs. IL-2 plus IFN-gamma did not show any significant changes except for eosinophilia (higher in protocol 1). Therefore, addition of IFN-gamma did not affect either lymphocyte distribution or non-MHC-restricted cytotoxicity in vivo. No difference in cell subpopulation or cytotoxicity was detected between responders and non-responders. Pre-treatment sTNF-alpha R concentration, in contrast to IL-6 and TNF-alpha, was significantly higher in progressive than in stable and responder groups, suggesting that this parameter may be predictive of the clinical response.

Anti-cytokines: promising tools for diagnosis and immunotherapy

Anti-cytokines belong to a new family of biological response modifiers which interfere with the biological functions of cytokines. An imbalance between cytokines and natural anti-cytokines may represent an important factor to explain the pathogenesis of some human diseases. Indeed, dysregulation of anti-cytokine serum levels was observed in cancers and auto-immune and infectious diseases. It was sometimes associated with disease activity and in some circumstances they may help to predict clinical response to treatment. Control of disease activity in septic shock and auto-immune diseases was demonstrated after administration of anti-cytokines such as soluble TNF receptors and IL1ra inhibitors. Therefore these agents are promising tools for diagnosis and immunotherapy.

Soluble tumour necrosis factor receptors (sTNF-R) and HIV infection: correlation to CD8+ lymphocytes

The objective of this study was to determine sTNF-R, type I (p55) and type II (p75) in sera of HIV-infected male homosexuals and correlate them to T lymphocyte subpopulations and course of HIV infection. Serum samples were obtained from 39 HIV-1+ asymptomatic male homosexuals, 10 symptomatic (ARC and AIDS) male homosexuals and 44 HIV- non-homosexual healthy controls. sTNF-R levels were determined by ELISA with specific MoAbs and polyclonal antibodies to the sTNF-R proteins. sTNF-RI and II levels were significantly elevated in 72% and 74% respectively of HIV+ asymptomatic male homosexuals and in all of the symptomatic male homosexuals. In sequential studies a highly significant positive correlation was found between sTNF-RI and sTNF-RII (r = 0.8, P < 0.001) and between both sTNF-R and CD8+ lymphocyte counts (r = 0.6 and 0.92, respectively, P < 0.01-0.001) during the asymptomatic stage of the infection. All these correlations were lost, however, during the symptomatic phase of the disease. These results suggest that: (i) HIV infection is associated with elevation of sTNF-R serum levels; (ii) sTNF-R levels are strongly correlated to CD8+ lymphocytes during the asymptomatic stage of HIV infection.

Interleukin-2. A review of its pharmacological properties and therapeutic use in patients with cancer

Recombinant interleukin-2 (IL-2) products (e.g. aldesleukin, teceleukin) are nonglycosylated, modified forms of the endogenous compound. IL-2 acts as a pleiotropic mediator within the immune system, having a variety of effects via specific cell surface receptors. The interaction of IL-2 with the IL-2 receptor induces proliferation and differentiation of a number of T lymphocyte subsets, and stimulates a cytokine cascade that includes various interleukins, interferons and tumour necrosis factors. Antitumour effects of IL-2 appear to be mediated by its effects on natural killer, lymphokine-activated killer (LAK) and other cytotoxic cells. In vivo and in vitro effects of IL-2 seem to be dependent to a large extent on the environment; many studies have reported conflicting results, perhaps due to diverse populations of effector cells, the availability of other cytokines that have synergistic or inhibitory influences, and the dosage regimens used. The recombinant products appear to be biologically indistinguishable from native IL-2 in vitro and in vivo; the former induce minor antibody formation but this does not appear to alter functional properties. In patients with metastatic renal cell carcinoma, IL-2 therapy achieves average objective response rates of 20% (range 0 to 40%), with a complete response rate of about 5% (range 0 to 19%). Response duration varies considerably but can be durable (lasting for > 12 months), with some patients remaining in complete response for > 60 months. It is unclear at present whether higher dosage regimens improve clinical response, or whether combination therapy with other agents and/or adoptive therapy is beneficial. Survival duration may depend on the risk factors present, with poorer performance status and more than one site of metastases associated with shorter survival times. Patients with metastatic malignant melanoma receiving IL-2 as monotherapy show an average objective response rate of 13% (range 3 to 24%); however, objective response rate averages 30% (range 4 to 59%) when IL-2 is used in combination with other agents. Overall median survival appears to be about 10 months. Preliminary data indicate that IL-2 produces a lower response rate in patients with refractory colorectal carcinoma, ovarian cancer, bladder cancer, acute myeloid leukemia or non-Hodgkin's lymphoma. Adverse effects accompanying high dose, intravenous IL-2 therapy can be severe, with cardiovascular, pulmonary, haematological, hepatic, neurological, endocrine, renal and/or dermatological complications frequently requiring doses to be withheld.(ABSTRACT TRUNCATED AT 400 WORDS)