Magnetic nanocarriers for the specific delivery of siRNA: Contribution of breast cancer cells active targeting for down-regulation efficiency.

The association between superparamagnetic iron oxide nanoparticles (SPION), carrying small interfering RNA (siRNA) as therapeutic agents and humanized anti- human epidermal growth factor receptor-2 (HER2) single-chain antibody fragments (scFv) for the active delivery into HER2-overexpressing cells appears as an interesting approach for patients with HER2-overexpressing advanced breast cancer. The obtained Targeted Stealth Magnetic siRNA Nanovectors (TS-MSN) are formulated by combining: (i) the synthesis protocol of Targeted Stealth Fluorescent Particles (T-SFP) which form the core of TS-MSN and (ii) the formulation protocol allowing the loading of T-SFP with polyplexes (siRNA and cationic polymers). TS-MSN have suitable physico-chemical characteristics for intravenous administration and protect siRNA against enzymatic degradation up to 24 h. The presence of HER2-targeting scFv on TS-MSN allowed an improved internalization (3-4 times more compared to untargeted S-MSN) in HER2-overexpressing breast cancer cells (BT-474). Furthermore, anti-survivin siRNA delivered by TS-MSN in HER2-negative breast-cancer control cells (MDA-MB-231) allowed significant down-regulation of the targeted anti-apoptotic protein of about 70%. This protein down-regulation increased in HER2+ cells to about 90% (compared to 70% with S-MSN in both cell lines) indicating the contribution of the HER2-active targeting. In conclusion, TS-MSN are promising nanocarriers for the specific and efficient delivery of siRNA to HER2-overexpressing breast cancer cells.

Versatile electrostatically assembled polymeric siRNA nanovectors: Can they overcome the limits of siRNA tumor delivery?

The application of small interfering RNA (siRNA) cancer therapeutics is limited by several extra- and intracellular barriers including the presence of ribonucleases that degrade siRNA, the premature clearance, the impermeability of the cell membrane, or the difficulty to escape endo-lysosomal degradation. Therefore, several delivery systems have emerged to overcome these limitations and to successfully deliver siRNA to the tumor site. This review is focused on polymer-based siRNA nanovectors which exploit the negative charge of siRNA, representing a major challenge for siRNA delivery, to their advantage by loading siRNA via electrostatic assembly. These nanovectors are easy to prepare and to adapt for an optimal gene silencing efficiency. The ability of electrostatically assembled polymeric siRNA nanovectors (EPSN) to improve the half-life of siRNA, to favor the specificity of the delivery and the accumulation in tumor and to enhance the cellular uptake and endosomal escape for an efficient siRNA delivery will be discussed. Finally, the influence of the versatility of the structure of these nanovectors on the protein down-regulation will be evaluated.

Bacterial cellulose hydrogel loaded with lipid nanoparticles for localized cancer treatment.

The use of hybrid materials, where a matrix sustains nanoparticles controlling the release of the chemotherapeutic drug, could be beneficial for the treatment of primary tumors prior or after surgery. This localized chemotherapy would guarantee high drug concentrations at the tumor site while precluding systemic drug exposure minimizing undesirable side effects. We combined bacterial cellulose hydrogel (BC) and nanostructured lipid carriers (NLCs) including doxorubicin (Dox) as a drug model. NLCs loaded with cationic Dox (NLCs-H) or neutral Dox (NLCs-N) were fully characterized and their cell internalization and cytotoxic efficacy were evaluated in vitro against MDA-MB-231 cells. Thereafter, a fixed combination of NLCs-H and NLCs-N loaded into BC (BC-NLCs-NH) was assayed in vivo into an orthotopic breast cancer mouse model. NLCs-H showed low encapsulation efficiency (48%) and fast release of the drug while NLCs-N showed higher encapsulation (97%) and sustained drug release. Both NLCs internalized via endocytic pathway, while allowing a sustained release of the Dox, which in turn rendered IC50 values below of those of free Dox. Taking advantage of the differential drug release, a mixture of NLCs-N and NLCs-H was encapsulated into BC matrix (BC-NLCs-NH) and assayed in vivo, showing a significant reduction of tumor growth, metastasis incidence and local drug toxicities.

Efficacy and Hemotoxicity of Stealth Doxorubicin-Loaded Magnetic Nanovectors on Breast Cancer Xenografts.

In the field of oncology, research is now focused on the development of theranostic nanosystems that combine the functions of drug delivery and imaging for diagnosis/monitoring. In this context, we designed polyethylene glycol (PEG)ylated superparamagnetic iron oxide nanoparticles (SPIONs) for the delivery of doxorubicin (DOX), an antineoplastic agent. These DOX-loaded PEGylated SPIONs, or DLPS, should be useful for the delivery of DOX in vivo, as well as for magnetic drug targeting (MDT) and magnetic resonance imaging (MRI). The aim of this study was to evaluate the potential applications of DLPS in vivo as drug carrier systems for the reduction of xenograft breast tumors induced in nude mice. Prior to the animal model experiments, the main internalization pathways for the nanovectors in MDA-MB435 breast cancer cells were determined to be based on caveolae- and clathrin-mediated endocytosis. The time- and quantity-dependence of the nanoparticle uptake by the cells altered the in vitro cytotoxicity of the DLPS. The in vitro antiproliferative effect of the DLPS was dependent not only on DOX concentration, but also on the efficacy of nanoparticle internalization. Evaluation of the effect of DLPS treatment on xenograft tumors in nude mice showed that DLPS limited tumor growth in a manner comparable to that of free DOX under normal conditions of tumor growth. The application of an external magnetic field on tumors, i.e., MDT, did not improve the efficacy of the DLPS treatment. Nevertheless, the vectorization of DOX with DLPS appears to limit the hematologic side effects usually associated with DOX treatment.

Design strategies of hybrid metallic nanoparticles for theragnostic applications.

Metallic nanoparticles (MNPs) such as iron oxide and gold nanoparticles are interesting platforms to build theragnostic nanocarriers which combine both therapeutic and diagnostic functions within a single nanostructure. Nevertheless, their surface must be functionalized to be suitable for in vivo applications. Surface functionalization also provides binding sites for targeting ligands, and for drug loading. This review focuses on the materials and surface chemistry used to build hybrid nanocarriers that are inorganic cores functionalized with organic materials. The surface state of the MNPs largely depends on their synthesis routes, and dictates the strategies used for functionalization. Two main strategies can be found in the literature: the design of core-shell nanosystems, or embedding nanoparticles in organic materials. Emerging tendencies such as the use of clusters or alternative coating materials are also described. To present both hydrophilic and lipophilic nanosystems, we chose the doxorubicin anticancer agent as an example, as the molecule presents an affinity for both types of materials.

Recent advances in theranostic nanocarriers of doxorubicin based on iron oxide and gold nanoparticles.

Hybrid (organic/inorganic) nanoparticles emerged as a simple solution to build "theranostic" systems. Due to their physical properties, superparamagnetic iron oxide nanoparticles (SPIONs) and plasmonic gold nanoparticles (Au-NPs) are extensively studied as a part of diagnostic and therapeutic strategies in cancer treatments. They can be used as agents for in vitro or in vivo imaging, for magnetic drug targeting and/or thermal therapy. Their functionalization with organic shells enhances their potential performance in tumor targeting and drug delivery. The advances in such hybrid nanocarriers are well illustrated with the example of the anticancer drug doxorubicin (DOX). The aim of this review is to give a multidisciplinary overview of such smart nanosystems loaded with DOX, based on examples taken from recent publications. From a physico-chemical point of view, we discuss the choices for the strategies for loading DOX and the consequences on drug release. From a biological point of view, we analyze the in vitro and in vivo assays concerning tumor imaging, targeted drug delivery and anticancer efficiency. Future opportunities and challenges are also addressed.

Pegylated magnetic nanocarriers for doxorubicin delivery: a quantitative determination of stealthiness in vitro and in vivo.

The aim of this work was to elucidate the impact of polyethylene glycol (PEG) polymeric coating on the in vitro and in vivo stealthiness of magnetic nanocarriers loaded or not with the anticancer drug doxorubicin. The comparison was made between aqueous suspensions of superparamagnetic iron oxide nanoparticles (SPIONs) stabilized by either citrate ions (C-SPIONs) or PEG(5000) (P-SPIONs), the latter being loaded or not with doxorubicin via the formation of a DOX-Fe(2+) complex (DLP-SPIONs). After determination of their relevant physico-chemical properties (size and surface charge), nanoparticle (NP) stealthiness was studied in vitro (ability to activate the complement system and uptake by monocytes and macrophage-like cells) and in vivo in mice (blood half-life; t(1/2), and biodistribution in main clearance organs). These aspects were quantitatively assessed by atomic absorption spectrometry (AAS). Complement activation dramatically decreased for sterically stabilized P-SPIONs and DLP-SPIONs in comparison with C-SPIONs stabilized by charge repulsion. Monocyte and macrophage uptake was also largely reduced for pegylated formulations loaded or not with doxorubicin. The t(1/2) in blood for P-SPIONs was estimated to be 76 ± 6 min, with an elimination mainly directed to liver and spleen. Thanks to their small size (<80 nm) and a neutral hydrophilic polymer-extended surface, P-SPIONs exhibit prolonged blood circulation and thus potentially an increased level in tumor delivery suitable for magnetic drug targeting applications.

Genes up- and down-regulated by dermcidin in breast cancer: a microarray analysis.

Dermcidin (DCD) is a human gene mapped to chromosome 12q13 region, which is co-amplified with multiple oncogenes with a well-established role in the growth, survival and progression of breast cancers. Here, we present a summary of a DNA microarray-based study that identified the genes that are up- and down-regulated in a human MDA-361 pLKO control clone and three clones expressing short hairpin RNA against three different regions of DCD mRNA. A list of 235 genes was differentially expressed among independent clones (> 3-fold change and p < 0.005). The gene expression of 208 was reduced and of 27 was increased in the three DCD-RNAi clones compared to pLKO control clone. The expression of 77 genes (37%) encoding for enzymes involved in amino acid metabolism, glucose metabolism and oxidoreductase activity and several genes required for cell survival and DNA repair were decreased. The expression of EGFR/ErbB-1 gene, an important predictor of outcome in breast cancer, was reduced together with the genes for betacellulin and amphiregulin, two known ligands of EGFR/ErbB receptors. Many of the 27 genes up-regulated by DCD-RNAi expression have not yet been fully characterized; among those with known function, we identified the calcium-calmodulin-dependent protein kinase-II delta and calcineurin A alpha. We compared 132 up-regulated and 12 down-regulated genes in our dataset with those genes up- and down-regulated by inhibitors targeting various signaling pathway components. The analysis showed that the genes in the DCD pathway are aligned with those functionally influenced by the drugs sirolimus, LY-294002 and wortmannin. Therefore, DCD may exert its function by activating the PI3K/AKT/mTOR signaling pathway. Together, these bioinformatic approaches suggest the involvement of DCD in the regulation of genes for breast cancer cell metabolism, proliferation and survival.

Resistance training alters cytokine gene expression in skeletal muscle of adults with type 2 diabetes.

Resistance training results in muscle hypertrophy and improves glycemic control in patients with type 2 diabetes. Whether resistance training modulates inflammation in muscles of diabetic patients remains unknown. We examined the expression of genes encoding the cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and transforming growth factor-beta1 (TGF-beta1) as well as the pan-leukocyte marker CD18. Thirty men and women (67+/-7 years) were randomized to either 16 weeks of resistance training and usual diabetes care (EX) or to usual diabetes care only (CON). Muscle biopsies were obtained from the vastus lateralis muscle prior to the 16-week intervention, and 72 h following the maximal strength test post-intervention. Fiber cross-sectional area (CSA) was determined following ATPase staining. Cytokine and CD18 transcript levels were assessed by real-time PCR. Resistance training increased CSA of type I and II fibers (both P <0.05) and IL-1beta transcript levels (P = 0.05). TNF-alpha (P<0.05) and TGF-beta1 transcripts (P<0.05) increased over time in the EX group, but these increases did not differ from those in the CON group. In both groups, the increase in CD18 transcripts remained minimal. The two groups differ by the relationship between changes in CD18 and changes in cytokine transcripts, suggesting that resistance training affects the source of cytokines in muscle. Our studies establish that resistance training in older adults with type 2 diabetes results in muscle fiber hypertrophy, despite a greater accumulation of inflammatory cytokine transcripts in muscle.

MyD88-dependent pathways mediate resistance to Cryptosporidium parvum infection in mice.

Cryptosporidium spp. cause diarrheal disease worldwide. Innate immune responses mediating resistance to this parasite are not completely understood. To determine whether MyD88-dependent pathways play a role in resistance to Cryptosporidium parvum, we compared the course of infection in MyD88(-/-) mice to that in their wild-type (WT) littermate controls. Three- to 4-week-old mice were infected with C. parvum, and infection was monitored by quantifying fecal oocyst shedding. Twelve days postinfection, the histology of the intestines was examined to quantify intestinal parasite burden and to determine if there were any pathological changes. Fecal oocyst shedding and intestinal parasite burden were significantly greater in MyD88(-/-) mice than in littermate controls. Nonetheless, both WT and MyD88(-/-) mice cleared the infection within 3 weeks. These results indicate that MyD88-dependent pathways are involved in mediating initial resistance to C. parvum. Since gamma interferon (IFN-gamma) is known to mediate resistance to C. parvum, we also studied infection in MyD88(-/-) mice and WT controls in which this cytokine was temporarily neutralized. Fecal oocyst shedding, as well as intestinal parasite burden, intestinal inflammation, and mortality, was significantly greater in MyD88(-/-) mice in which IFN-gamma was neutralized than in IFN-gamma-neutralized WT mice or in MyD88(-/-) mice in which this cytokine was active. These results suggest that MyD88 and IFN-gamma had an additive effect in conferring protection from C. parvum infection. While this study confirms the importance of IFN-gamma in conferring resistance to infection with C. parvum, it suggests that MyD88-mediated pathways also play a role in innate immunity to this parasite.

Classification of technical pitfalls in objective universal hearing screening by otoacoustic emissions, using an ARMA model of the stimulus waveform and bootstrap cross-validation.

Transient-evoked otoacoustic emissions (TEOAE) are widely used for objective hearing screening in neonates. Their main shortcoming is their sensitivity to adverse conditions for sound transmission through the middle-ear, to and from the cochlea. We study here whether a close examination of the stimulus waveform (SW) recorded in the ear canal in the course of a screening test can pinpoint the most frequent middle-ear dysfunctions, thus allowing screeners to avoid misclassifying the corresponding babies as deaf for lack of TEOAE. Three groups of SWs were defined in infants (6-36 months of age) according to middle-ear impairment as assessed by independent testing procedures, and analyzed in the frequency domain where their properties are more readily interpreted than in the time domain. Synthetic SW parameters were extracted with the help of an autoregressive and moving average (ARMA) model, then classified using a maximum likelihood criterion and a bootstrap cross-validation. The best classification performance was 79% with a lower limit (with 90% confidence) of 60%, showing the results' consistency. We therefore suggest that new parameters and methodology based upon a more thorough analysis of SWs can improve the efficiency of TEOAE-based tests by helping the most frequent technical pitfalls to be identified.

BAEPs averaging analysis using autoregressive modelling.

OBJECTIVE: The present paper introduces a new perspective on the classical ensemble averaging which can be useful to analyse the Brainstem Auditory Evoked Potentials (BAEPs). The analysis of the dynamics, related to the BAEP, is performed directly after its acquisition from the electroencephalogram (EEG). METHODS: The method primarily consists of dynamically modelling the averaged potential, obtained during the acquisition mode. Each averaging of signal at a given instant is considered as an autoregressive (AR) process. RESULTS: It has been shown that the predicting error power of AR modelling can be useful to provide an efficient tool to analyse the BAEPs. It has also been shown that the method is capable of taking the non-stationarities of both the BAEP and the EEG into account. CONCLUSION: In order to validate our approach, the proposed technique has been implemented for both simulated and real signals. This approach can also be employed in the context of estimating other evoked potentials and shows rich promise for potential clinical applications in future.

Imbalance between interleukin-1 agonists and antagonists: relationship to severity of inflammatory bowel disease.

Interleukin (IL)-1 is a key mediator in the pathogenesis of inflammatory bowel disease (IBD). Naturally occurring IL-1 modulators include IL-1 receptor antagonist (IL-1Ra), IL-1 soluble receptor Type I (IL-1sRI), IL-1sRII and IL-1 receptor accessory protein (AcP). Systemic and mucosal levels of IL-1 soluble receptors remain unknown in IBD. Plasma or colonic tissues were obtained from 185 consecutive unselected patients with Crohn's disease (CD) or ulcerative colitis (UC) and from 52 control subjects. Plasma and colonic explant culture supernatants were assessed for IL-1alpha, IL-1beta, IL-1Ra, IL-1sRI and IL-1sRII. Plasma IL-1Ra levels were higher in UC (+93%) than in healthy subjects. IL-1alpha and IL-1beta were not detected. IL-1sRII levels were marginally lower in CD (-10%) and UC (-9%), whereas IL-1sRI levels were elevated in CD (+28%) only. Plasma IL-1sRI levels correlated positively (P < 0.01) with Crohn's disease activity index (r = 0.53), C-reactive protein (r = 0.46) and alpha1-acid glycoprotein (r = 0.42). In colonic explant cultures, IL-1alpha and IL-1Ra levels were elevated in non-lesional (+233% and +185% respectively) and lesional CD (+353% and +1069%), lesional UC (+604% and +1138%), but not in non-lesional UC. IL-1beta was elevated in lesional UC (+152%) and CD (+128%). In contrast, IL-1sRII levels were elevated in non-lesional CD (+65%), but remained unchanged in lesional CD, non-lesional and lesional UC. IL-1sRI levels did not differ between patient and control groups. These results indicate that (i) the proinflammatory moiety IL-1sRI is a systemic marker of inflammation and activity in CD and (ii) local shedding of the functional antagonist IL-1sRII may dampen colonic inflammation in CD, but not in UC.

Effects of aging and cytokine blockade on inflammatory cachexia.

OBJECTIVE: To evaluate the role of aging and specific cytokine blockade in the etiology of cachexia caused by adjuvant arthritis (AA), a model of cytokine-associated cachexia. METHODS: AA was induced in Lewis rats using CFA. In Experiment 1, severity of AA and inflammatory cachexia was assessed in young (Y, age 2-6 months, n = 132) and old rats (O, age 18-22 months, n = 40). In Experiment 2, young rats were divided into 5 different intervention groups: Saline-injected (n = 66); CFA-injected (n = 78); CFA-injected and treated with IL-1 receptor antagonist (IL-1Ra, n = 18); CFA-injected and treated with soluble TNF receptor type I (sTNFrI, n = 27); and CFA-injected and treated with both IL-1Ra and sTNFrI (both treatments, n = 8). RESULTS: In Experiment 1, young Lewis rats developed more severe arthritis (mean joint score on day 21 = 5.1 +/- 0.3) compared to the old group (0.6 +/- 0.6, p < 0.0001). The young group with AA lost 2.1% of baseline total body weight loss compared to 13.8% total body weight gain in controls (p < 0.0001). In contrast, old rats injected with CFA lost as much weight (-11%) as age-matched saline injected controls (-13%, p > 0.05, n = 18, age 18-22 months). In Experiment 2, mean joint scores in rats treated with IL-1Ra, sTNFrI or both were higher then untreated rats injected with CFA (p < 0.0001). Despite this, rats given both IL-1Ra and sTNFrI lost less weight on day 16 (p < 0.01) and 21 (p < 0.002) than untreated rats or those rats treated with either IL-1Ra or sTNFrI. CONCLUSION: Lewis rats aged 2-6 months are more susceptible to developing AA than older rats (age range 18-22 months). Inhibition of both IL-1 and TNF is needed to mitigate AA-associated weight loss, and this effect is dissociated from the effect of such inhibition on joint inflammation.

Computer-assisted ABR interpretation using the automatic construction of the latency-intensity curve.

In this paper, we present a new computerised technique for the automatic construction of the latency intensity curve (LI curve). We take a pattern recognition approach determined by a priori information. We use knowledge gained from the audiogram and from physiological considerations. Therefore, we consider all recordings at different intensities as well as results from the extraction of a single auditory brainstem response (ABR) at a given stimulus intensity. We tested our method successfully: it allows us to prevent misrecognition errors in response detection or in latency measurements. Automatic recognition of the waves and recognition by the ear, nose and throat (ENT) specialist coincided in at least 90 per cent of cases. For wave V, the average deviation between the response thresholds given by our automatic recognition algorithm and those given by the ENT specialist was 5 dB, and the average deviation of the latencies was 0.05 ms.

IL-1B and IL-1Ra gene polymorphisms and disease severity in rheumatoid arthritis: interaction with their plasma levels.

The balance between interleukin-1 (IL-1) and its competitive antagonist IL-1 receptor antagonist (IL-1Ra) may contribute to the pathogenesis of rheumatoid arthritis (RA). We analysed the frequency of different alleles in the IL-1B gene (at -511 and at +3954) as well as in the IL-1Ra gene (at +2018) in an association study involving 297 RA patients and 112 healthy controls from the same geographic area. We tested associations with RA susceptibility or severity, and with circulating levels of IL-1Ra and IL-1beta. Carriage of the rare IL-1B (+3954) allele 2 was increased in destructive arthritis (DRA) as compared to non-destructive arthritis (NDRA) (OR 1.7, 95% CI 1.1-2.8, 49.0% vs 35.9%) and controls (OR 1.7, 95% CI 1.1-2.8, 35.8%). Patients carrying this allele had a more destructive (Larsen wrist radiological index: mean +/- s.e.m., 2.1 +/- 0.2 vs 1.6 +/- 0.1, P = 0.005; Steinbrocker functional index: 2.4 +/- 0.1 vs 1.9 +/- 0.1, P = 0.002) and active disease (Ritchie articular index: 8.1 +/- 0.8 vs 5.3 +/- 0.6, P = 0.002; erythrocyte sedimentation rate (ESR): 36.6 +/- 2.9 mm/h vs 25.3 +/- 1.8 mm/h, P = 0.002). This contribution was independent from that of HLA DR4/DR1 to severity. IL-1Ra plasma levels adjusted to ESR values were significantly lower in IL-1B2 (+3954) positive than negative RA patients (1.0 +/- 0.1 vs 1.2 +/- 0.1 ng/ml, P = 0.01). This IL-1B (+3954) gene polymorphism may be an important marker for the severity of joint destruction in RA and is associated with an imbalance in IL-1Ra production. As this genetic association was independent and additive to the risk of HLA DR4/DR1 status, it could be a useful addition to HLA-DR4/1 as a genetic prognostic marker early in the course of the disease.

IL-4 VNTR gene polymorphism in chronic polyarthritis. The rare allele is associated with protection against destruction.

OBJECTIVE: To evaluate the occurrence of variants of the interleukin 4 (IL-4) and IL-4 receptor (IL-4R) genes in patients with rheumatoid arthritis (RA) and their possible contribution to joint destruction. METHODS: Allelic frequencies for polymorphisms in the IL-4 [variable number of tandem repeat (VNTR) polymorphism in intron 3] and IL-4 receptor alpha chain (transition at nucleotide 1902) genes were assessed in 335 RA patients and 104 controls. Clinical indices of disease activity, disability and joint destruction and plasma levels of IL-1beta, IL-1Ra and sCD23 were assessed to evaluate a possible functional effect. RESULTS: Carriage of the rare IL-4(2) allele was higher in patients with non-destructive RA (40%) than in those with destructive RA (22.3%; odds ratio = 1.9, 95% confidence interval 1. 1-3.5, P = 0.0006) and in controls (26%, P = 0.002). Patients positive for this rare allele had significantly less joint destruction, assessed by the Larsen wrist index (P = 0.004) and a lower erythrocyte sedimentation rate (P = 0.04). A significantly higher carriage rate of IL-4(2) was seen in HLA-DR4/DR1(-) patients with non-destructive RA than in those with destructive RA. The IL-4 receptor polymorphism was not over-represented. Plasma levels of IL-1beta, IL-1Ra and sCD23, known to be modified by IL-4, were not different in individuals having different alleles. CONCLUSION: This IL-4 VNTR gene polymorphism may be a protective factor for severe joint destruction in RA that could be used as a prognostic marker early in the course of the disease.

Elevated circulating levels of soluble interleukin-1 receptor type II during interleukin-2 immunotherapy.

Interleukin-1 (IL-1) is a critical mediator of inflammation. Two naturally occurring IL-1 antagonists have been described, namely the IL-1 receptor antagonist (IL-1Ra) and the IL-1 receptor type II (IL-1RII). IL-1RII does not transmit a signal upon binding of IL-1, but competes with the signaling of IL-1RI for binding of IL-1. Shedding of IL-1RII yields the soluble IL-1 receptor type II (IL-1sRII) which retains the ability of membrane-bound IL-1RII to bind IL-1beta avidly, but binds IL-1Ra and IL-1alpha with low affinity. In contrast, IL-1sRI retains the ability of membrane-bound IL-1RI to bind IL-1Ra and IL-1alpha with high affinity, but binds IL-1beta poorly. We have previously shown that immunotherapy with IL-2 or IL-6 in cancer patients is associated with a dramatic increase in IL-1Ra plasma levels. In the present study, plasma levels of soluble IL-1 receptors were monitored in healthy individuals and cancer patients. In healthy controls, the mean IL-1sRII level was 4.76 0.16 ng/ml. IL-1sRII levels in cancer patients were comparable to those measured in healthy controls. IL-1sRII levels did not vary during the first 52 hours after initiation of IL-2 therapy, but increased significantly thereafter to reach 9.56 1.16 ng/ml on day 5. In contrast, IL-6 immunotherapy with a 5-day continuous infusion did not trigger an increase in IL-1sRII levels. IL-1sRI levels did not increase during immunotherapy with IL-2 or IL-6. Our results indicate that IL-1sRII, unlike IL-1Ra, remains a modest, natural, anti-inflammatory mechanism triggered by immunotherapy with IL-2, but not with IL-6.

Elevated levels of soluble interleukin-1 receptor type II and interleukin-1 receptor antagonist in patients with chronic arthritis: correlations with markers of inflammation and joint destruction.

OBJECTIVE: To compare plasma levels of interleukin-1 receptor antagonist (IL-1Ra), soluble IL-1 receptor type I (sIL-1RI), and soluble IL-1 receptor type II (sIL-1RII) in patients with chronic polyarthritis, and to establish correlations between levels of these naturally occurring IL-1 inhibitors and indices of disease activity and joint destruction. METHODS: Levels of IL-1Ra, sIL-1RI, and sIL-1RII were measured in plasma samples from patients with chronic polyarthritis, using specific radioimmunoassays. Levels were correlated with indices of disease activity and joint destruction. RESULTS: Plasma levels of IL-1Ra, sIL-1RI, and sIL-1RII were significantly higher in polyarthritis patients than in controls. IL-1Ra levels correlated positively with all indices of disease activity and joint destruction (P < 0.0001). In contrast, sIL-1RII levels correlated negatively with indices of joint destruction, such as the Larsen score in the wrist (P < 0.04). Interestingly, sIL-1RII levels were higher in patients with nondestructive arthritis (Larsen score < or =1) than in patients with destructive arthritis. Levels of sIL-1RI did not correlate with indices of disease activity or joint destruction. CONCLUSION: The present findings indicate that increased levels of IL-1Ra, a natural antiinflammatory acute-phase protein, may reflect increased production and activity of IL-1. In contrast, endogenous sIL-1RII, unlike sIL-1RI, may constitute a natural antiinflammatory factor in chronic polyarthritis. These differences should be taken into account when these antiinflammatory molecules are considered as prognostic markers or for therapeutic use.

Both C3a and C3a(desArg) regulate interleukin-6 synthesis in human peripheral blood mononuclear cells.

Synthesis of complement components is part of the acute-phase response. Interleukin-6 (IL-6) is a critical mediator of the acute-phase response during infections and injuries. Plasma levels of C3a and IL-6 have been proposed as prognostic indicators in sepsis and trauma. The effects of C3a and C3a(des)Arg on IL-6 gene expression and protein production in human peripheral blood mononuclear cells (PBMC) were investigated. Neither C3a nor C3a(des)Arg alone induced detectable IL-6 protein or mRNA levels. However, C3a and C3a(des)Arg affected endotoxin-induced IL-6 synthesis in a dose-dependent manner. In nonadherent PBMC, C3a or C3a(des)Arg suppressed, while in adherent PBMC, C3a or C3a(des)Arg enhanced IL-6 protein and mRNA levels. These results suggest that C3a and C3a(des)Arg may provide a control mechanism of acute-phase responses by enhancing IL-6 synthesis in adherent monocytes at local inflammatory sites and by inhibiting IL-6 synthesis in circulating monocytes.