Possible Curative Effects of Boric Acid and Bacillus clausii Treatments on TNBS-Induced Ulcerative Colitis in Rats

Crohn's disease (CD) and ulcerative colitis (UC) are two chronic relapsing inflammatory bowel diseases (IBD). Although there are several treatment options available to improve the symptoms of IBD patients, there is no effective treatment that provides a definitive solution. In the present study, we aim to investigate the antioxidative/anti-inflammatory effects of oral administration of boric acid and Bacillus clausii in a rat trinitrobenzenesulfonic acid (TNBS)-induced colitis model. The effects of boric acid and B. clausii were examined in serum and colon tissues with the help of some biochemical and histological analyses. Elevated inflammation and oxidative damage were found in the blood and colon tissue samples in the TNBS-induced group according to the complete blood count (CBC), tumor necrosis factor (TNF) alpha, interleukin-35 (IL-35), malondialdehyde (MDA), glutathione peroxidase (GPx), myeloperoxidase (MPO), nitric oxide (NO), and histological findings. Particularly, the highest IL-35 level (70.09 ± 12.62 ng/mL) in the combined treatment group, highest catalase activity (5322 ± 668.1 U/mg protein) in the TNBS-induced group, and lower relative expression of inducible nitric oxide synthase in the TNBS-induced group than the control group were striking findings. According to our results, it can be concluded that boric acid showed more curative effects, even if B. clausii probiotics was partially ameliorative.

Transmembrane protein TMEM184B is necessary for interleukin-31-induced itch

ABSTRACT

Nociceptive and pruriceptive neurons in the dorsal root ganglia (DRG) convey sensations of pain and itch to the spinal cord, respectively. One subtype of mature DRG neurons, comprising 6% to 8% of neurons in the ganglia, is responsible for sensing mediators of acute itch and atopic dermatitis, including the cytokine IL-31. How itch-sensitive (pruriceptive) neurons are specified is unclear. Here, we show that transmembrane protein 184B (TMEM184B), a protein with roles in axon degeneration and nerve terminal maintenance, is required for the expression of a large cohort of itch receptors, including those for interleukin 31 (IL-31), leukotriene C4, and histamine. Male and female mice lacking TMEM184B show reduced responses to IL-31 but maintain normal responses to pain and mechanical force, indicating a specific behavioral defect in IL-31-induced pruriception. Calcium imaging experiments indicate that a reduction in IL-31-induced calcium entry is a likely contributor to this phenotype. We identified an early failure of proper Wnt-dependent transcriptional signatures and signaling components in Tmem184b mutant mice that may explain the improper DRG neuronal subtype specification. Accordingly, lentiviral re-expression of TMEM184B in mutant embryonic neurons restores Wnt signatures. Together, these data demonstrate that TMEM184B promotes adult somatosensation through developmental Wnt signaling and promotion of proper pruriceptive gene expression. Our data illuminate a new key regulatory step in the processes controlling the establishment of diversity in the somatosensory system.

The protective effects of Olmesartan against interleukin-29 (IL-29)-induced type 2 collagen degradation in human chondrocytes

Osteoarthritis (OA) is a cartilage degenerative disease commonly observed in the elderly population and is pathologically characterized by the degradation of the cartilage extracellular matrix (ECM). Matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) are critical enzymes involved in the degradation of ECM. Olmesartan is an inhibitor of the angiotensin II receptor developed for the treatment of hypertension, and recent studies show that it exerts anti-inflammatory effects in arthritis. The present study aimed to investigate the mechanism of the protective effect of Olmesartan on cartilage ECM degradation. Interleukin-29 (IL-29) is a novel inflammatory mediator involved in the inflammation and degradation of cartilage in OA, and human T/C-28a2 cells treated with it were the inflammatory model in vitro. We found that the degradation of type 2 collagens and aggrecans was induced by IL-29, accompanied by the upregulation of MMPs and ADAMTSs, but the presence of Olmesartan significantly ameliorated these increases. In addition, Olmesartan abolished IL-29- induced oxidative stress and elevated the expression level of TNF receptor-associated factor 6 (TRAF-6). Mechanistically, we showed that Olmesartan suppressed IL-29- caused inhibitor kappa B α (IκBα) expression and nuclear translocation of nuclear factor kappa-B (NF-κB) p65, indicating it suppressed the activation of the NF-κB pathway. Collectively, our data reveal that Olmesartan exerted a protective function on IL-29- induced type 2 collagen degradation in human chondrocytes.

Metformin suppresses interleukin-22 induced hepatocellular carcinoma by upregulating Hippo signaling pathway

BACKGROUND AND AIMS

Epidemiological studies have shown direct associations between type 2 diabetes and the risk of cancers. Accumulating evidence indicates that metformin is profoundly implicated in preventing tumor development. However, the exact mechanism underlying the antitumor effects of metformin in hepatocellular carcinoma (HCC) is still not clear.

METHODS

In this study, we investigated the effects of metformin on a mouse HCC model and interleukin-22 (IL-22)-associated carcinogenesis in vitro.

RESULTS

We found that metformin significantly suppressed the incidence and tumor burden of HCC in the diethyl-nitrosamine-induced HCC mouse model. As expected, the expression of IL-22, an important factor involved in HCC progression, was markedly reduced by metformin. Treatment of HCC cells with metformin inhibited IL-22 induced cell proliferation, migration, and invasion, and promoted cell apoptosis. Furthermore, ectopic expression of IL-22 makes HCC more aggressive, whereas metformin largely compromised it in vitro and in vivo. Mechanistically, the whole transcriptome analysis and functional analysis revealed that Hippo signaling pathway was involved in the antitumor ability of metformin. Consistent with this, metformin directly inhibited LATS1/2 and activated Mst1/2, phosphorylated YAP1 in vitro. After blocking the Hippo pathway by XMU-MP-1, the inhibitor of MST1/2, the inhibitory effects by metformin were dramatically attenuated as shown by in vitro study.

CONCLUSIONS

Collectively, our findings illuminate a new regulatory mechanism, metformin activates Hippo signaling pathway to regulate IL-22 mediated HCC progression and provide new insights into its tumor-suppressive roles.

A Double Edged Sword Role of Interleukin-22 in Wound Healing and Tissue Regeneration

Wound healing and tissue regeneration is an intricate biological process that involves repair of cellular damage and maintenance of tissue integrity. Cascades involved in wound healing and tissue regeneration highly overlap with cancer causing pathways. Usually, subsequent tissue damage events include release of a number of cytokines to accomplish post-trauma restoration. IL-22 is one of the cytokines that are immediately produced to initiate immune response against several tissue impairments. IL-22 is a fundamental mediator in inflammation, mucous production, protective role against pathogens, wound healing, and tissue regeneration. However, accumulating evidence suggests pivotal role of IL-22 in instigation of various cancers due to its pro-inflammatory and tissue repairing activity. In this review, we summarize how healing effects of IL-22, when executed in an uncontrollable fashion can lead to carcinogenesis.

Interleukin-22 promotes the migration and invasion of oral squamous cell carcinoma cells

The roles of interleukin-22 (IL-22) in carcinogenesis have been proposed in various neoplasms. Increased expression of IL-22 has been observed in oral squamous cell carcinoma (OSCC) lesions as well as in other cancers. OSCC is still associated with poor prognosis and a high mortality rate because of its invasiveness and frequent lymph node metastasis. In the present study, we investigated the effects of IL-22 on OSCC cells. The human OSCC cell lines Ca9-22 and SAS were stimulated with IL-22 (1-10 ng/mL), and their migration abilities were examined using a cell scratch assay. A Matrigel invasion assay was performed to evaluate the invasion abilities of OSCC cells. Signal transducer and activator of transcription 3 (STAT3) phosphorylation, matrix metalloproteinase (MMP) and epithelial-mesenchymal transition (EMT)-related genes and proteins were also examined. IL-22 treatment promoted the migration and invasion abilities of OSCC cells without increasing their viability. IL-22 stimulation also induced STAT3 phosphorylation, MMP-9 activity and EMT-related genes and proteins. Our findings suggest that IL-22 has possible roles in the development of OSCC.

Epidermal CD147 expression plays a key role in IL-22-induced psoriatic dermatitis

Psoriasis is a chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation and terminal differentiation. Interleukin-22 (IL-22) and the transcription factor Stat3 play pivotal roles in the pathogenesis of psoriasis. CD147 is a transmembrane glycosylation protein that belongs to the immunoglobulin superfamily. Our previous studies have shown that CD147 is a marker of high keratinocyte proliferation and poor keratinocyte differentiation as well as a psoriasis susceptibility gene. The current study demonstrates that CD147 is highly expressed in psoriatic skin lesions. Specific CD147 over-expression in the epidermis of K5-promoter transgenic mice promotes imiquimod (IMQ)-induced psoriasis-like inflammation characterized by acanthosis, granular layer loss and inflammatory cell infiltration. We also found that IL-22 increases CD147 transcription in vitro and in vivo and that Stat3 binds directly to the CD147 promoter between positions -854 and -440, suggesting that CD147 expression is up-regulated in patients with psoriasis through Stat3 activation. In addition, CD147 knockdown dramatically blocks IL-22-mediated Stat3 activation as well as IL-22-induced cytokine, chemokine and antimicrobial factor expression. Together, these findings show that CD147 is a novel and key mediator of IL-22-induced psoriatic alterations in the epidermis and might be a therapeutic target in patients with psoriasis.

A Randomized Study of Peginterferon Lambda-1a Compared to Peginterferon Alfa-2a in Combination with Ribavirin and Telaprevir in Patients with Genotype-1 Chronic Hepatitis C

BACKGROUND

A randomized, double-blind, multinational, phase 3 study was conducted comparing the efficacy and safety of peginterferon lambda-1a (Lambda)/ribavirin (RBV)/telaprevir (TVR) vs. peginterferon alfa-2a (Alfa)/RBV/TVR in patients with chronic hepatitis C virus (HCV) genotype-1 (GT-1) infection.

METHODS

Patients (treatment-naïve or relapsers on prior Alfa/RBV treatment) were randomly assigned in a 2:1 ratio to receive Lambda/RBV/TVR or Alfa/RBV/TVR. Total duration of treatment was either 24 or 48 weeks (response-guided treatment), with TVR administered for the first 12 weeks. The primary endpoint was the proportion of patients who achieved a sustained virologic response at post treatment week 12 (SVR12), which was tested for noninferiority of Lambda/RBV/TVR.

RESULTS

A total of 838 patients were enrolled, and 617 were treated; 411 and 206 patients received Lambda/RBV/TVR and Alfa/RBV/TVR, respectively. The majority of patients were treatment-naïve, with HCV GT-1b and a high baseline viral load (≥800,000 IU/mL). Less than 10% of patients had cirrhosis (Lambda, 7.5%; Alfa, 6.8%). Lambda/RBV/TVR did not meet the criterion for noninferiority (lower bound of the treatment difference interval was -12.3%); the SVR12 in all patients (modified intent-to-treat) was 76.2% in the Lambda arm and 82.0% in the Alfa arm. Overall, the frequency of adverse events in each arm was comparable (Lambda, 91.7%; Alfa, 97.1%). As expected based on the safety profile of the 2 interferons, there were more hepatobiliary events observed in the Lambda arm and more hematologic events in the Alfa arm.

CONCLUSIONS

In this comparison of Lambda/RBV/TVR and Alfa/RBV/TVR in patients who were treatment-naïve or had relapsed on prior Alfa/RBV treatment, Lambda failed to demonstrate noninferiority based on SVR12 results. Treatment with Lambda/RBV/TVR was associated with a higher incidence of relapse. More patients discontinued Lambda/RBV/TVR treatment during the first 4 weeks of study treatment, mainly due to hepatobiliary-related events, and more Lambda patients were lost to follow-up.

Daclatasvir/peginterferon lambda-1a/ribavirin in patients with chronic HCV infection and haemophilia who are treatment naïve or prior relapsers to peginterferon alfa-2a/ribavirin

AIM

This study explores the potential role of a novel interferon-containing regimen for treatment of patients with chronic hepatitis C (CHC) and underlying haemophilia.

METHODS

This trial (NCT01741545) was an open-label, non-randomized phase 3 study, which included adult haemophiliacs with hepatitis C virus (HCV). Patients with HCV genotypes (GT)-2 or -3 were treated with Lambda-IFN/ribavirin (RBV)/daclatasvir (DCV) for 12 weeks (cohort A). Patients with HCV GT-1b or -4 were treated with Lambda-IFN/RBV/DCV for 12 weeks, followed by Lambda-IFN/RBV for an additional 12 weeks (cohort B). The primary endpoint was the proportion of patients with a sustained virologic response at post-treatment follow-up week 12 (SVR12). Clinical development of Lambda-IFN was discontinued during this trial leading to study termination before a 24-week post-treatment follow-up was obtained for all participants.

RESULTS

Overall, 51 patients were treated (cohort A, n = 12; cohort B, n = 39). The proportion of patients achieving SVR12 was 92% in cohort A and 90% in cohort B. Therapy was generally well tolerated. The most common adverse events (AEs) were related to elevations in serum transaminases and/or bilirubin. Five serious AEs, four discontinuations due to AEs, and no deaths were reported. The rate of grade 3-4 bilirubin elevations was 17-18% across cohorts.

CONCLUSION

Lambda-IFN/RBV/DCV treatment demonstrated a high SVR rate and was generally well tolerated with a safety profile consistent with expectations for this special patient population. This study supports use of DCV as part of a combination treatment regimen for haemophiliacs with CHC.

Derivation of Phase 3 dosing for peginterferon lambda-1a in chronic hepatitis C, Part 2: Exposure-response analyses for efficacy and safety variables

This is the second of two manuscripts detailing the pharmacodynamic derivation of peginterferon lambda-1a (Lambda) dosing and treatment durations for Phase 3 studies in hepatitis C virus (HCV) infection, based on Phase 2 data. Herein, we describe the derivation of regression models for 12-week on-treatment virologic response and safety outcomes at 120, 180, and 240 μg Lambda with ribavirin. In patients with HCV genotypes 1 or 4, there was a significant (P = 0.024) relationship between undetectable HCV-RNA at Week 4 and Lambda exposure (AUC or Cmax ), with the largest difference between adjacent dose levels between the 180 and 120 μg exposure ranges. Risk of Grade 3-4 aminotransferase or bilirubin elevations relative to a peginterferon alfa-2a/ribavirin control were related to Lambda exposure for all patients, and the largest increase between adjacent dose levels was seen for 240 versus 180 μg. Anemia and neutropenia events were lower than control across all doses and exposures. Based on these data and those in our previous manuscript, Phase 3 studies will evaluate fixed 180 µg doses of Lambda in combination with ribavirin and a direct-acting antiviral for 24-48 weeks in HCV genotypes 1 or 4 or 12-24 weeks in genotypes 2 or 3.

Interferons: Success in anti-viral immunotherapy

The interferons (IFNs) are glycoproteins with strong antiviral activities that represent one of the first lines of host defense against invading pathogens. These proteins are classified into three groups, Type I, II and III IFNs, based on the structure of their receptors on the cell surface. Due to their ability to modulate immune responses, they have become attractive therapeutic options to control chronic virus infections. In combination with other drugs, Type I IFNs are considered as "standard of care" in suppressing Hepatitis C (HCV) and Hepatitis B (HBV) infections, while Type III IFN has generated encouraging results as a treatment for HCV infection in phase III clinical trials. However, though effective, using IFNs as a treatment is not without the need for caution. IFNs are such powerful cytokines that affect a wide array of cell types; as a result, patients usually experience unpleasant symptoms, with a percentage of patients suffering system wide effects. Thus, constant monitoring is required for patients treated with IFN in order to reach the treatment goals of suppressing virus infection and maintaining quality of life.

Maintenance of intestinal Th17 cells and reduced microbial translocation in SIV-infected rhesus macaques treated with interleukin (IL)-21

In pathogenic HIV and SIV infections of humans and rhesus macaques (RMs), preferential depletion of CD4⁺ Th17 cells correlates with mucosal immune dysfunction and disease progression. Interleukin (IL)-21 promotes differentiation of Th17 cells, long-term maintenance of functional CD8⁺ T cells, and differentiation of memory B cells and antibody-secreting plasma cells. We hypothesized that administration of IL-21 will improve mucosal function in the context of pathogenic HIV/SIV infections. To test this hypothesis, we infected 12 RMs with SIV(mac239) and at day 14 post-infection treated six of them with rhesus rIL-21-IgFc. IL-21-treatment was safe and did not increase plasma viral load or systemic immune activation. Compared to untreated animals, IL-21-treated RMs showed (i) higher expression of perforin and granzyme B in total and SIV-specific CD8⁺ T cells and (ii) higher levels of intestinal Th17 cells. Remarkably, increased levels of Th17 cells were associated with reduced levels of intestinal T cell proliferation, microbial translocation and systemic activation/inflammation in the chronic infection. In conclusion, IL-21-treatment in SIV-infected RMs improved mucosal immune function through enhanced preservation of Th17 cells. Further preclinical studies of IL-21 may be warranted to test its potential use during chronic infection in conjunction with antiretroviral therapy.

IL-22 in tissue-protective therapy

IL-22, a member of the IL-10 cytokine family, has recently gained significant attention as a protective agent in murine models of diseases driven by epithelial injury. Like its biochemical and functional sibling IL-10, IL-22 elicits cellular activation primarily by engaging the STAT3 signalling pathway. Exclusively produced by leukocytes, but targeting mostly cells of epithelial origin, IL-22 has been proposed as a specialized cytokine messenger acting between leukocytic and non-leukocytic cell compartments. A lack of response in leukocytes to IL-22 mirrors tightly controlled IL-22 receptor expression and probably explains the apparent lack of instant adverse effects after systemic IL-22 administration to mice. Anti-apoptotic, pro-proliferative and pro-regenerative characteristics the major biological properties of this cytokine. Specifically, application of IL-22 is associated with tissue protection and/or regeneration in murine models of infection/microbe-driven inflammation at host/environment interfaces, ventilator-induced lung injury, pancreatitis and liver damage. Overall, preclinical studies would support therapeutic administration of seemingly well-tolerated recombinant IL-22 for treatment of an array of acute diseases manifested in epithelial tissues. However, the feasibility of prolonged administration of this cytokine is expected to be restricted by the tumourigenic potential of the IL-22/STAT3 axis. IL-22, moreover, apparently displays an inherent context-specific capacity to amplify distinct aspects of autoimmune inflammation. Here, the prospects, expectations and restrictions of IL-22 administration in tissue-protective therapy are discussed.

Comparison of vascular leak syndrome in mice treated with IL21 or IL2

Interleukin 21 (IL21) is a T-cell-derived 4-helix-bundle cytokine that has sequence homology to the IL2 family. Recombinant human interleukin 2 (rIL2) is approved for the treatment of metastatic melanoma and renal cell carcinoma. However, toxicity of rIL2, including induction of vascular leak syndrome (VLS), has limited use of this cytokine to a small proportion of eligible patients. Both rIL2 and murine IL21 (mIL21) have potent antitumor efficacy in murine models. The purpose of the current study was to compare the ability of mIL21 and rIL2 to induce vascular leakage in a mouse model. Pulmonary and hepatic uptake of Evans blue dye, serum cytokine levels, spleen cell immunophenotype, and histologic changes in lung and liver were evaluated to detect VLS. High-dose (200 μg) rIL2 treatment induced vascular leakage in mice, evidenced by inflammatory cell infiltration and fluid extravasation into the lung and liver and increased levels of TNFα, IFNγ, IL5, MCP1, and IL6 in serum. In contrast, an equivalent dose of mIL21 resulted in minimal vascular leakage with no evidence of cytopenia or cytokine production. These results support the use of IL21 as a cancer immunotherapeutic agent, potentially providing an antitumor response without induction of VLS.

IL-33 independently induces eosinophilic pericarditis and cardiac dilation: ST2 improves cardiac function

BACKGROUND

IL-33 through its receptor ST2 protects the heart from myocardial infarct and hypertrophy in animal models but, paradoxically, increases autoimmune disease. In this study, we examined the effect of IL-33 or ST2 administration on autoimmune heart disease.

METHODS AND RESULTS

We used pressure-volume relationships and isoproterenol challenge to assess the effect of recombinant (r) IL-33 or rST2 (eg, soluble ST2) administration on the development of autoimmune coxsackievirus B3 myocarditis and dilated cardiomyopathy in male BALB/c mice. The rIL-33 treatment significantly increased acute perimyocarditis (P=0.006) and eosinophilia (P=1.3×10(-5)), impaired cardiac function (maximum ventricular power, P=0.0002), and increased ventricular dilation (end-diastolic volume, P=0.01). The rST2 treatment prevented eosinophilia and improved heart function compared with rIL-33 treatment (ejection fraction, P=0.009). Neither treatment altered viral replication. The rIL-33 treatment increased IL-4, IL-33, IL-1β, and IL-6 levels in the heart during acute myocarditis. To determine whether IL-33 altered cardiac function on its own, we administered rIL-33 to undiseased mice and found that rIL-33 induced eosinophilic pericarditis and adversely affected heart function. We used cytokine knockout mice to determine that this effect was due to IL-33-mediated signaling but not to IL-1β or IL-6.

CONCLUSIONS

We show for the first time to our knowledge that IL-33 induces eosinophilic pericarditis, whereas soluble ST2 prevents eosinophilia and improves systolic function, and that IL-33 independently adversely affects heart function through the IL-33 receptor.

A phase I study of recombinant human interleukin-21 (rIL-21) in combination with sunitinib in patients with metastatic renal cell carcinoma (RCC)

BACKGROUND

sunitinib induces partial responses in 47% of patients with metastatic renal cell carcinoma (mRCC). However, the achievement of complete responses remains scarce and all patients will eventually develop progressive disease. Recombinant interleukin-21 (rIL-21) is a novel cytokine, which is believed to deliver sustained cellular anti-tumor response and the combination of both agents may work synergistically.

MATERIAL AND METHOD

from July 2007 to July 2008 in this phase I trial nine therapy-naive patients with metastatic RCC in five European centers were enrolled. Patients with either good or intermediate risk according to Memorial Sloan-Kettering Cancer Center (MSKCC) were eligible without restrictions to histology subtype nor measurable disease. Patients were treated with increasing doses of rIL-21 administered subcutaneously (s.c.) in combination with sunitinib 50 mg once daily (OD) orally at the '4 weeks on/2 weeks off' schedule. Dose-escalation was applied by a conventional '3+3 design'. Planned dose levels (DL) for rIL-21 were 3, 10, 30 and 100 microg/kg s.c. The primary endpoint was to determine the maximum tolerated dose (MTD) and recommended dose (rd). secondary objectives included pharmacokinetics of sunitinib and ril-21, and the induction of ril-21 antibodies.

RESULTS

at 10 microg/kg two dose-limiting toxicities (DLT) occurred in four patients, consisting of grade 4 neutropenia and grade 3 thrombocytopenia. The MTD was 3 microg/kg rIL-21 combined with sunitinib 50 mg OD at the '4 weeks on/2 weeks off' schedule. Frequent occurring adverse events were injection site reaction, stomatitis, fatigue and dysgeusia.

CONCLUSIONS

the combination of sunitinib 50 mg at the '4 weeks on/2 weeks off' schedule and 10 microg/kg IL-21 was not tolerated due to hematological DLTs. The dose level of 3 microg/kg rIL-21 was considered too low to be therapeutically relevant for further evaluation and therefore the study was discontinued.

Phase 1b study of pegylated interferon lambda 1 with or without ribavirin in patients with chronic genotype 1 hepatitis C virus infection

Interferon lambda 1 (IFN-lambda1) is a type III IFN that produces intracellular responses similar to those of IFN-alpha but in fewer cell types because of differences in the receptor distribution pattern, and this could potentially result in an improved safety profile. This was an open-label three-part study of patients with chronic hepatitis C virus (HCV) genotype 1 infection. Part 1 evaluated single-agent pegylated interferon lambda (PEG-IFN-lambda) at 1.5 or 3.0 microg/kg administered every 2 weeks or weekly for 4 weeks in patients who had relapsed after previous IFN-alpha-based treatment. Part 2 evaluated weekly doses of PEG-IFN-lambda ranging from 0.5 to 2.25 microg/kg in combination with ribavirin (RBV) for 4 weeks in treatment-relapse patients. Part 3 evaluated weekly PEG-IFN-lambda at 1.5 microg/kg in combination with RBV for 4 weeks in treatment-naive patients. Fifty-six patients were enrolled: 24 patients in part 1, 25 patients in part 2, and 7 patients in part 3. Antiviral activity was observed at all PEG-IFN-lambda dose levels (from 0.5 to 3.0 microg/kg). Two of seven treatment-naive patients (29%) achieved rapid virological response. Treatment was well tolerated with minimal flu-like symptoms and no significant hematologic changes other than RBV-associated decreases in hemoglobin. The most common adverse events were fatigue (29%), nausea (12%), and myalgia (11%). Six patients experienced increases in aminotransferases that met protocol-defined criteria for dose-limiting toxicity (DLT) or temporarily holding therapy with PEG-IFN-lambda. Most DLT occurred in patients with high PEG-IFN-lambda exposure.

CONCLUSION

Weekly PEG-IFN-lambda with or without daily RBV for 4 weeks is well tolerated with minimal adverse events and hematologic effects and is associated with clear antiviral activity across a broad range of doses in patients with chronic HCV.

Preclinical and clinical development of pegylated interferon-lambda 1 in chronic hepatitis C

Current treatment of chronic hepatitis C consists of pegylated interferon-alpha (PEG-IFN-alpha) in combination with ribavirin. This regimen is associated with adverse effects that can limit its use. PEG-IFN-lambda 1 (pegIFNlambda) is a novel IFN that shares many of the biological effects of IFN-alpha but may have fewer side effects due to its more selective receptor distribution. Preclinical data show that pegIFNlambda has antiviral activity against hepatitis C virus (HCV) but does not inhibit myeloid colony formation. A phase 1 study in healthy volunteers demonstrated that pegIFNlambda is well tolerated. Elevated liver enzymes resulted in a dose-limiting toxicity after a single dose of 7.5 microg/kg, the highest dose tested. A phase 1b study in genotype 1 HCV patients who either relapsed after IFN-alpha therapy or naive to therapy was initiated. Interim data from the treatment relapse subset showed viral load reductions of 2.3 to 4.0 logs when pegIFNlambda was administered weekly as a single agent with or without ribavirin for up to 4 weeks. Drug-related side effects included elevation of liver enzymes. Decreases in hemoglobin were observed only in patients receiving ribavirin. Constitutional symptoms appeared lower than historical data for PEG-IFN-alpha. These results form the basis of further development of pegIFNlambda as a novel treatment for chronic hepatitis C.

Molecular pathophysiology of psoriasis and molecular targets of antipsoriatic therapy

Psoriasis is a chronic inflammatory skin disease characterised by elevated red scaly plaques on specific body sites. Histologically, the plaques are defined by epidermal hyperplasia, epidermal and dermal infiltration by leukocytes, and changes in the dermal microvasculature. Differentiation and activation are disturbed in lesional psoriatic keratinocytes, and the pool of proliferating keratinocytes is increased, which is accompanied by enhanced production of proinflammatory cytokines, adhesion molecules and antimicrobial peptides. These changes in psoriatic keratinocytes are caused by altered expression of genes associated with epidermal differentiation, and by activation of signalling pathways involving signal transducer and activator of transcription 3 (STAT3), type I interferon (IFN) and mitogen-activated protein kinase (MAPK). The number of T cells, and myeloid and plasmacytoid dendritic cells (DCs) is markedly increased in psoriatic lesions. Myeloid DCs produce interleukin (IL)-23, tumour necrosis factor (TNF)-alpha and inducible nitric oxide synthase (iNOS), which are crucial cytokines in the pathogenesis of psoriasis. IL-23 stimulates the secretion of IL-22 by T helper 17 cells, and IL-22 induces epidermal hyperplasia. The crosstalk between keratinocytes and leukocytes via their proinflammatory cytokines creates the vicious circle of chronic skin inflammation seen in psoriasis. This suggests that optimal treatment of psoriasis needs to target pathogenic pathways in both leukocytes and keratinocytes.

Anti-inflammatory and pro-inflammatory roles of TGF-beta, IL-10, and IL-22 in immunity and autoimmunity

Cytokines play a major role in maintaining lymphocyte homeostasis under both steady-state and inflammatory conditions. Unregulated lymphocytes in steady-state conditions can lead to autoimmunity, whereas during inflammation they can cause excessive tissue damage. Regulatory cytokines function in combination with other environmental signals to properly modulate the function and the extent of lymphocyte activation. Many recent studies have highlighted the importance of regulatory cytokines in controlling the differentiation and function of lymphocytes under steady-state and inflammatory conditions, as well as minimizing tissue damage.

Neuropsychiatric disorders related to interferon and interleukins treatment

Certain cytokines such as interferon-alpha and interleukin-2 are often used in the treatment certain cancers and chronic diseases such as melanoma, hepatitis C infection and multiple sclerosis. Several neuropsychiatric side effects such as depression, anxiety, psychosis, suicidal ideation, hypomanic mood and cognitive impairment were reported in those patients who received those medications. In certain patients with those neuropsychiatric side effects, the symptoms ceased when the medication was stopped. However, in some cases, the cognitive impairment persisted even for years after cessation of the medication. In animal studies, those cytokines could induce sickness behaviour, anxiety behaviour and social anhedonia. The increased in pro-inflammatory cytokines in certain neuropsychiatric disorders was widely reported. In addition, in animal studies, the treatment with interferon-alpha or interleukin-1 could induce depressive like behaviour. Recently, the role of certain pro-inflammatory cytokines that could enhance the activity of the enzyme, indoleamine 2-3, dioxygenase (IDO) which in turn would increase tryptophan degradation into kynurenine and decrease tryptophan availability of tryptophan in the brain to synthesize serotonin, a neurotransmitter which is necessary for the normal mood state became of interest in pathophysiology of psychiatric disorders. Furthermore, the imbalance in the further downward catabolic kynurenine pathway and their interactions with other neurotransmitters has been proposed to play an important role. The presence of such an imbalance in patients being treated with cytokines and in patients with psychiatric disorders and the possible consequence of those changes on the neuroprotective function in the brain are discussed in this review.

An Open-Label, Two-Arm, Phase I Trial of Recombinant Human Interleukin-21 in Patients with Metastatic Melanoma

Purpose: Human interleukin-21 (IL-21) is a pleiotropic class I cytokine that activates CD8+ T cells and natural killer cells. We report a phase 1 study of recombinant human IL-21 in patients with surgically incurable metastatic melanoma. The primary objective was to investigate safety and tolerability by determining dose-limiting toxicity (DLT). The secondary objectives were to identify a dose response for various biomarkers in the peripheral blood, estimate the minimum biologically effective dose, determine the pharmacokinetics of IL-21, determine if anti-IL-21 antibodies were induced during therapy, and measure effects on tumor size according to Response Evaluation Criteria in Solid Tumors.

Experimental Design: Open-label, two-arm, dose escalation trial of IL-21 administered by i.v. bolus injection at dose levels from 1 to 100 μg/kg using two parallel treatment regimens: thrice weekly for 6 weeks (3/wk) or three cycles of daily dosing for 5 days followed by 9 days of rest (5+9).

Results: Twenty-nine patients entered the study. IL-21 was generally well tolerated and no DLTs were observed at the 1, 3, and 10 μg/kg dose levels. In the 3/wk regimen, DLTs were increased in alanine aminotransferase, neutropenia, and lightheadedness with fever and rigors. DLTs in the 5+9 regimen were increased in aspartate aminotransferase and alanine aminotransferase, neutropenia, fatigue, and thrombocytopenia. The maximum tolerated dose was declared to be 30 μg/kg for both regimens. Effects on biomarkers were observed at all dose levels, including increased levels of soluble CD25 and up-regulation of perforin and granzyme B mRNA in CD8+ cells. One partial tumor response observed after treatment with IL-21 for 2 × 6 weeks (3/wk) became complete 3 months later.

Conclusions: IL-21 is biologically active at all dose levels administered and is generally well tolerated, and phase 2 studies have commenced using 30 μg/kg in the 5+9 regimen.

Interleukin-23 and interleukin-27 exert quite different antitumor and vaccine effects on poorly immunogenic melanoma

Recent studies revealed that two novel interleukin (IL)-12-related cytokines, IL-23 and IL-27, have potent antitumor activities. However, the antitumor effects were mainly evaluated in relatively highly immunogenic tumors and have not been fully evaluated against nonimmunogenic or poorly immunogenic tumors. In this study, we investigated the antitumor efficacies of IL-23 and IL-27 on poorly immunogenic B16F10 melanoma and found that the antitumor responses mediated by IL-23 and IL-27 were clearly different. In syngeneic mice, mouse single-chain (sc) IL-23-transfected B16F10 (B16/IL-23) tumors exhibited almost the same growth curve as B16F10 parental tumor about until day 20 after tumor injection and then showed growth inhibition or even regression. In contrast, scIL-27-transfected B16F10 (B16/IL-27) tumors exhibited significant retardation of tumor growth from the early stage. In vivo depletion assay revealed that the antitumor effect of B16/IL-23 was mainly mediated by CD8+ T cells and IFN-gamma whereas that of B16/IL-27 mainly involved natural killer cells and was independent of IFN-gamma. We also found that antitumor effects of B16/IL-23 and B16/IL-27 were synergistically enhanced by treatment with IL-18 and IL-12, respectively. Furthermore, B16/IL-23-vaccinated mice developed protective immunity against parental B16F10 tumors but B16/IL-27-vaccinated mice did not. When combined with prior in vivo depletion of CD25+ T cells, 80% of B16/IL-23-vaccinated mice completely rejected subsequent tumor challenge. Finally, we showed that the systemic administration of neither IL-23 nor IL-27 induced such intense toxicity as IL-12. Our data support that IL-23 and IL-27 might play a role in future cytokine-based immunotherapy against poorly immunogenic tumors.

IL-25 enhances allergic airway inflammation by amplifying a TH2 cell-dependent pathway in mice

BACKGROUND

A novel IL-17 family cytokine, IL-25, has been reported to induce IL-4, IL-5, and IL-13 production from undefined non-T/non-B cells and then induce T(H)2-type immune responses. However, the roles of IL-25 in inducing allergic airway inflammation remain unknown.

OBJECTIVE

We sought to determine whether IL-25 is involved in causing allergic airway inflammation.

METHODS

We examined the expression of IL-25 mRNA in the lungs of sensitized mice on antigen inhalation. We also examined the effect of IL-25 neutralization by soluble IL-25 receptor on antigen-induced airway inflammation. We then generated IL-25 transgenic mice that express IL-25 specifically in the lung under the control of the Clara cells-10-kd protein promoter and investigated the effect of enforced IL-25 expression on antigen-induced airway inflammation.

RESULTS

IL-25 mRNA was expressed in the lungs of sensitized mice on antigen inhalation, and the neutralization of IL-25 by soluble IL-25 receptor decreased antigen-induced eosinophil and CD4(+) T-cell recruitment into the airways. The enforced expression of IL-25 in the lung itself failed to induce allergic airway inflammation, whereas the expression of IL-25 significantly enhanced antigen-induced T(H)2 cytokine production, eosinophil and CD4(+) T cell recruitment, and goblet cell hyperplasia in the airways. Moreover, IL-25-induced enhancement of allergic airway inflammation was inhibited by the depletion of CD4(+) T cells or by the absence of signal transducer and activator of transcription 6.

CONCLUSION

IL-25 enhances antigen-induced allergic airway inflammation by amplifying a T(H)2 cell-dependent pathway.

CLINICAL IMPLICATIONS

IL-25 might be involved in the enhancement, prolongation, or both of T(H)2 cell-mediated allergic diseases, such as asthma.

Clinical and local biological effects of an intratumoral injection of mda-7 (IL24; INGN 241) in patients with advanced carcinoma: a phase I study

The melanoma differentiation-associated gene-7 (mda-7; approved gene symbol IL24) is a tumor suppressor gene whose expression induces selective apoptosis in tumor cells. To characterize the safety and biologic activity of mda-7 gene transfer, we conducted a phase I trial using intratumoral injections of an adenovirus containing the mda-7 construct (Ad-mda7; INGN 241; 2 x 10(10) to 2 x 10(12) vp) in 28 patients with resectable solid tumors. One hundred percent of injected lesions demonstrated INGN 241 vector transduction, transgenic mRNA, elevated MDA-7 protein, and apoptosis induction, with the highest levels near the injection site. Apoptosis of cells in injected tumors was consistently observed even in heavily pretreated patients. INGN 241 vector DNA and mRNA were detected more than 1 cm from the injection site, whereas MDA-7 protein and bioactivity were more widely distributed. Toxicity attributable to the injections was self-limiting and generally mild; however, one patient experienced a grade 3 SAE possibly related to the study drug. Evidence of clinical activity was found in 44% of lesions with the repeat injection schedule, including complete and partial responses in two melanoma patients. Thus intratumoral administration of INGN 241 is well tolerated, induces apoptosis in a large percentage of tumor cells, and demonstrates evidence of clinically significant activity.

Perinatal inflammatory cytokine challenge results in distinct neurobehavioral alterations in rats: implication in psychiatric disorders of developmental origin

Maternal stress, viral infection, and obstetric complications, which trigger cytokine signaling, are hypothesized to be involved in schizophrenia and its related disorders. The etiologic contribution of individual cytokines to such psychiatric disorders, however, remains to be evaluated. To estimate the impact of peripheral cytokine challenge on neurobehavioral development, we examined effects of four proinflammatory cytokines on rat neonates and their later behavioral performance. Sublethal doses of interleukin-1 alpha, interleukin-2, interleukin-6, or interferon-gamma were subcutaneously administered to rat pups for 9 days. These animals displayed alterations in physical development, including lower weight gain and/or accelerated eyelid opening. In addition, behavioral abnormalities related to fear/anxiety levels and sensorimotor gating emerged at different developmental stages, depending on the cytokine species administered. During juvenile stages, neonatal interleukin-2 treatment increased exploratory locomotor activity, whereas other cytokine treatments did not. At the post-puberty stage, however, the interleukin-2-induced abnormal motor activity became undetectable, whereas interleukin-1 alpha-treated rats developed abnormalities in startle response, prepulse inhibition (PPI), and social interaction. Subchronic treatment of an anti-psychotic drug, clozapine, ameliorated the impairment of prepulse inhibition without altering startle responses. These animal experiments illustrate that, during early postnatal development, inflammatory cytokine challenge in the periphery can induce future psycho-behavioral and/or cognitive impairments with various latencies, although the pathologic mechanisms underlying these abnormalities remain to be determined.

Transduction of the IL-21 and IL-23 genes in human pancreatic carcinoma cells produces natural killer cell-dependent and -independent antitumor effects

We examined whether novel cytokines, interleukin (IL)-21 and IL-23, that were expressed in tumors could produce antitumor effects in the inoculated mice. Human pancreatic cancer AsPC-1 cells were retrovirally transduced with murine IL-21 or IL-23 (p19-linked p40) gene (AsPC-1/IL-21, AsPC-1/IL-23) and were injected into nude or severe combined immunodeficiency (SCID) mice. Although the proliferation in vitro of the transduced cells remained the same as that of parent cells, growth of AsPC-1/IL-21 and AsPC-1/IL-23 tumors developed in nude mice was retarded compared with that of parent tumors. Treatment of nude mice with anti-asialo GM(1) antibody temporally abrogated the growth retardation of AsPC-1/IL-21, but not AsPC-1/IL-23 tumors; however, the growth of AsPC-1/IL-21 tumors came to be retarded thereafter with the regeneration of natural killer (NK) cells. The growth of AsPC-1/IL-21 tumors developed in SCID mice was also retarded compared with parent tumors and the growth retardation was abrogated by treatment with anti-asialo GM(1) antibody. The growth of AsPC-1/IL-23 tumors in SCID mice was not different from that of parent tumors. Cytotoxic activity and secretion of interferon-gamma in response to AsPC-1 cells were induced in spleen cells of the mice bearing AsPC-1/IL-21 or AsPC-1/IL-23 tumors. When nude mice were injected with a mixed population of AsPC-1/IL-21 and AsPC-1/IL-23 cells, no synergistic effects were observed. These data collectively suggest that expression of IL-21 and IL-23 in tumors can produce NK cell-dependent and -independent antitumor effects in an alpha beta T cell-defective condition, respectively.

A fatal cytokine-induced systemic inflammatory response reveals a critical role for NK cells

The mechanism of cytokine-induced shock remains poorly understood. The combination of IL-2 and IL-12 has synergistic antitumor activity in vivo, yet has been associated with significant toxicity. We examined the effects of IL-2 plus IL-12 in a murine model and found that the daily, simultaneous administration of IL-2 and IL-12 resulted in shock and 100% mortality within 4 to 12 days depending on the strain employed. Mice treated with IL-2 plus IL-12 exhibited NK cell apoptosis, pulmonary edema, degenerative lesions of the gastrointestinal tract, and elevated serum levels of proinflammatory cytokines and acute phase reactants. The actions of TNF-alpha, IFN-gamma, macrophage-inflammatory protein-1alpha, IL-1, IL-1-converting enzyme, Fas, perforin, inducible nitric oxide synthase, and STAT1 did not contribute to the observed toxicity, nor did B or T cells. However, toxicity and death from treatment with IL-2 plus IL-12 could be completely abrogated by elimination of NK cells. These results suggest that the fatal systemic inflammatory response induced by this cytokine treatment is critically dependent upon NK cells, but does not appear to be mediated by the known effector molecules of this cellular compartment. These data may provide insight into the pathogenesis of cytokine-induced shock in humans.

Are cytokines in platelet concentrates responsible for febrile transfusion reactions?

In recent years, several studies have identified the leukocyte content and the age of the blood components as dominant factors in febrile transfusion reactions (FTRs). At present, extensive efforts are being made to reduce adverse effects by implementation and/or introduction of new methods for leuko-depletion of blood components and by studying the mechanisms responsible for these phenomena. A recent approach has been the evaluation of cytokines in platelet concentrates and this issue has been addressed with some detail in this review. Comparative data currently available on levels of cytokines in the different platelet concentrates is provided along with the functional role of the detected cytokines in including adverse reactions.

Safety of human recombinant proteins

Recombinant human proteins play an important role in therapy, especially in stimulating the hematopoiesis after chemotherapy, e.g., erythropoietin and colony stimulating factors, while several promising candidates such as IL-6, IL-12, thrombopoietin and others are in clinical development. Since the recombinant proteins are copies of endogenous proteins, it was assumed that they would be well tolerated. While this assumption is correct for some, other proteins proved to be less well tolerated. Therefore, preclinical safety assessment of these proteins is necessary. Based on the experience with several proteins, some guidance for the safety assessment can be given. Furthermore, data are presented demonstrating that preclinical toxicity studies may have a predictive value for man. Limitations of the classical approach of safety tests and new concepts are discussed.

Interleukins: the search for an anticancer therapy

OBJECTIVES

To review each of the interleukins, identify their common toxic effects, and highlight the potential role of interleukins in cancer therapy.

DATA SOURCES

Research articles, abstracts, review articles, and book chapters related to interleukins.

CONCLUSIONS

Interleukins play a key role in coordinating complex immune defense mechanisms against microbe invasion and cancer. The process of genetic engineering has made an increasing number of these interleukins available as biopharmaceuticals for evaluation of their potential roles as a cancer therapeutic agent.

IMPLICATIONS FOR NURSING PRACTICE

Nurses are challenged to understand and manage better both common and unusual side effects of interleukin therapies and provide appropriate patient and family education.

Are interleukin-2 and interleukin-15 tumor promoting factors for human non-hematopoietic cells?

Human normal non hematopoietic cells of mesenchymal and neuroectodermal origin may express functional IL-Rs. For instance, in these cell types, IL-2 can stimulate proliferation (endothelial, intestinal and nervous cells) or modify the expression of adhesion molecules (fibroblasts) or inhibit proliferation (bone marrow stromal cells). Therefore, some cytotoxic effects described during IL-2 biotherapy could be due to a direct interaction between IL-2 and non-hematopoietic tissues. The expression of functional IL-2-R has also been reported in several human cell lines derived from solid tumors. In some instances IL-2 inhibits cell growth (head and neck, gastric and renal carcinomas), but in other tumors, growth stimulation and increased expression of markers of tumor progression have been reported (intestinal, breast, and lung carcinomas, gliomas, fibrosarcomas and melanomas). Additionally, secretion of biologically active IL-2 has been reported in some melanoma and breast cancer cell lines. Transcripts for the novel cytokine IL-15, which utilizes the beta and gamma chains of the IL2-R, have been found in melanoma cells and anti-IL-15 mAbs inhibit HLA class I expression in these cells. Therefore these cytokines may modify, inside a tumor, the behavior of both stromal and neoplastic cells. All these data may have important implications in our understanding of tumor host interactions and in future strategies of immunotherapy.

Cutaneous reactions to recombinant cytokine therapy

Cytokines are critical to several fundamental homeostatic mechanisms such as fever, acute phase reactions, wound healing, hematopoiesis, inflammation, cellular and humoral immune responses, and tumor regression. As a result of advances in recombinant DNA technology, recombinant cytokines are available as therapeutic agents. They have been used for metastatic cancers and immunodeficiencies, as a therapy for naturally occurring or drug-induced anemias or leukopenias, and they have also been applied to some cutaneous disorders. Cytokine therapy can result in toxic reactions that affect many organ systems, especially the skin. These reactions are common and diverse, ranging from minor injection site reactions, pruritus, and flushing to life-threatening autoimmune disorders, severe erythroderma, or bullous skin reactions. This review focuses on the major cytokines that are in current clinical use or under investigation and describes the cutaneous complications of these agents.

Recombinant human hematopoietic growth factors in the treatment of cytopenias

The hemolymphopoietic growth factors, including the colony-stimulating factors (CSF) and interleukins (IL), are described and categorized on the basis of their biological features in laboratory systems. Although these agents are varied and exceptions exist, in general they lack lineage specificity although they may express lineage-predominant activity. They act at multiple levels of hemolymphopoietic cell differentiation, demonstrate additive or synergistic effects when combined in vitro, require surface receptors on target cells to directly express their activity, and may be produced by a variety of cells. This framework of behavioral generalizations, completed by the specifics of each factor's activity, despite the artifactual and simplified nature of in vivo systems, forms the basis for concepts of in vitro activity and for clinical applications. Hemolymphopoietic growth factors studied in the clinic have demonstrated impressive and important activity, validating much of the in vitro data. Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have clearly reduced neutropenia and infection rates when administered following conventional chemotherapy and high-dose chemotherapy followed by autologous bone marrow transplantation. To a varying degree, similar results with G-CSF and/or GM-CSF have been described in other diseases including acute myelogenous leukemia (AML) treated following induction chemotherapy, myelodysplastic syndrome, hairy cell leukemia, aplastic anemia, and chronic neutropenias. In preliminary studies IL-3 has been shown to have similar qualitative activities. However, these agents have not demonstrated a reproducible salutary impact on platelet or red cell lineages. Adverse effects on platelet counts and/or platelet recovery have been noted. Additionally, hemolymphopoietic growth factor receptors have been identified on malignant cells, suggesting that these factors could stimulate neoplastic growth. Studies with GM-CSF and IL-3 have demonstrated blast proliferation in some cases of AML and myelodysplasia, underscoring the capacity of these agents to stimulate the growth of myeloid leukemia. No clinically evident impact of these factors upon the growth of solid tumors has been identified but this issue has not been adequately studied. The toxicity of these agents has been surprisingly limited and appears to be related to their biologic activities. Hemolymphopoietic growth factors as single agents have broad clinical applications in cytopenias. Several methods for enhancing the clinical activity of these agents are under study, including the use of combinations of growth factors synergistic in vitro.

The future of cytokine combination therapy

The hematopoietic growth factors including colony-stimulating factors (CSF) and interleukins (IL) have overlapping and pleiotropic effects on proliferation and differentiation of progenitor cells and stem cells. The regulatory signals can influence terminal differentiation and the cell cycle status, self-renewal, and differentiation of early pluripotential stem cells. Synergistic interactions between CSF and IL have been shown, both in vitro and in vivo, to be critical in hematopoietic regulation. The future of clinical trials of cytokines in congenital and acquired myelosuppressed states lies in the selective use of appropriate combinations of these regulatory macromolecules.

Recent advances in the management of biotherapy-related side effects: fatigue

Limited information about fatigue patterns in patients with cancer exists in the biotherapy literature. When fatigue is mentioned, it is usually to state whether or not it was a dose-limiting side effect. No further data are provided on how fatigue was measured; which patterns were noted and when; and which relationships were found between fatigue and demographic characteristics, type of biologic response modifier, route of administration, or cumulative dose. Thus, there is little available in the biotherapy literature to guide nursing practice in managing this side effect. Theory that guides practice, however, often emanates from the personal experiences of the patients and from the clinical observations and intuitive hunches of the nurses and physicians participating in clinical trials. These individuals have been most generous in sharing their insights and unpublished data with the authors. This paper presents a comprehensive view of current knowledge on fatigue to guide present nursing practice with patients receiving biotherapy and to provide direction for future nursing and clinical trial research.

[Immunopathological analysis of T and non-T cell involvement in corneal inflammation caused by HSV type-1 infection]

In herpetic keratitis, the role of T cell subsets is not clearly understood although the involvement of cell-mediated immunity has been reported. The purpose of this paper is to analyse T cell-mediated immunopathological conditions and the role of non-T cell lineage in herpetic stromal keratitis employing nude (nu/nu) and Balb/c mice. All mice were divided into three groups. Group 1: Herpes simplex virus type 1 (HSV-1)-inoculated nu/nu mice. Group 2: HSV-1-inoculated nu/nu mice with interleukin-2 (IL-2). Group 3: HSV-1-inoculated Balb/c mice. The conditions of the disease were compared in those three groups clinically and by using histological and immunopathological staining. Following antibodies were employed: anti-Asialo GMI (natural killer). anti-Thy 1 (pan-T). anti-L3T4 (helper/inducer), anti-Lyt 2 (suppressor/killer), anti-Mac 3 (macrophage), anti-Mice Immunoglobulins (monocyte. B.). Corneal lesions showed a reduced inflammatory tendency in nu/nu mice. Topical application of IL-2 in nu/nu mice induced moderate stromal inflammation compared with nu/nu mice. However, the severity of these was less than in Balb/c. Many natural killer cells (NK) were found in nu/nu mice but few in Balb/c mice. These results confirm the involvement of T-cell mediated immunity in stromal inflammation and indicate that NK cell may have an important role in suppressed T-cell immunity in nu/nu mice but are not involved in stromal inflammation.

Central nervous system toxicity of interferons and other cytokines

Prolonged administration of interferons, interleukins and tumor necrosis factor are accompanied by a range of toxic effects of which central nervous system toxicity may be an important dose-limiting factor. While symptoms are widely reported, practically nothing is known about mechanisms of action. This review attempts to distinguish between a direct effect of cytokines upon circumventricular organs and an indirect effect mediated by factors released by endothelial-glial cells of the blood-brain barrier normally impermeable to cytokines. In order to reduce the toxicity of biological response modifiers the definition of the minimum effective dose, the use of the lymphatic route and the observance of the chronobiological rules may help to improve the therapeutic index of these hormone-like compounds. It appears however, that the relationship between cytokine: dose: route: schedule: timing on one side and efficacy: toxicity on the other is complex, and so far no general rule has clearly emerged so that at the moment it appears necessary to find out the optimal therapeutic index for each particular disease.