Interferon-gamma: a review

Delivery of Immobilized IFN-γ With PCN-333 and Its Effect on Human Mesenchymal Stem Cells

Interferon-gamma (IFN-γ) plays a vital role in modulating the immunosuppressive properties of human mesenchymal stem/stromal cells (hMSCs) used in cell therapies. However, IFN-γ suffers from low bioavailability and degrades in media, creating a challenge when using IFN-γ during the manufacturing of hMSCs. Metal-organic frameworks (MOFs), with their porous interiors, biocompatibility, high loading capacity, and ability to be functionalized for targeting, have become an increasingly suitable platform for protein delivery. In this work, we synthesize the MOF PCN-333(Fe) and show that it can be utilized to immobilize and deliver IFN-γ to the local extracellular environment of hMSCs. In doing so, the cells proliferate and differentiate appropriately with no observed side effects. We demonstrate that PCN-333(Fe) MOFs containing IFN-γ are not cytotoxic to hMSCs, can promote the expression of proteins that play a role in immune response, and are capable of inducing indoleamine 2,3-dioxygenase (IDO) production similar to that of soluble IFN-γ at lower concentrations. Overall, using MOFs to deliver IFN-γ may be leveraged in the future in the manufacturing of therapeutically relevant hMSCs.

Crosslinked Layered Surfaces of Heparin and Poly(L-Lysine) Enhance Mesenchymal Stromal Cell Behavior in the Presence of Soluble Interferon Gamma

Human mesenchymal stromal cells (hMSCs) are multipotent cells that have been proposed for the treatment of immune-mediated diseases. Culturing hMSCs on tissue culture plastic reduces their therapeutic potential in part due to the lack of extracellular matrix components. The aim of this study is to evaluate multilayers of heparin and poly(L-lysine) (HEP/PLL) as a bioactive surface for hMSCs stimulated with soluble interferon gamma (IFN-γ). Multilayers were formed, via layer-by-layer assembly, with HEP as the final layer and supplemented with IFN-γ in the culture medium. Multilayer construction and chemistry were confirmed using Azure A staining, quartz crystal microbalance, and X-ray photoelectron spectroscopy. hMSCs adhesion, viability, and differentiation, were assessed. Results showed that (HEP/PLL) multilayer coatings were poorly adhesive for hMSCs. However, performing chemical crosslinking using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide significantly enhanced hMSCs adhesion and viability. The immunosuppressive properties of hMSCs cultured on crosslinked (HEP/PLL) multilayers were confirmed by measuring indoleamine 2,3-dioxygenase activity. Lastly, hMSCs cultured on crosslinked (HEP/PLL) multilayers in the presence of soluble IFN- γ successfully differentiated towards the osteogenic and adipogenic lineages as confirmed by Alizarin red, and oil-red O staining, as well as alkaline phosphatase activity. This study suggests that crosslinked (HEP/PLL) films can modulate hMSCs response to soluble factors, which may improve hMSCs-based therapies aimed at treating several immune diseases.

Inhibition of LPS-Induced Microglial Activation by the Ethyl Acetate Extract of Pueraria mirifica

Microglial activation has been found to play a crucial role in various neurological disorders. Proinflammatory substances overproduced by activated microglia, such as cytokines, chemokines, reactive oxygen species, and nitric oxide (NO), can result in neuroinflammation that further exacerbates the course of the diseases. This study aimed to explore the anti-inflammatory effect of the ethyl acetate extract of Pueraria mirifica on microglial activation. Lipopolysaccharide (LPS)-induced inflammation was used as a model to investigate the effects of P. mirifica on HAPI (highly aggressive proliferating immortalized), a rat microglial cell line. Administration of ethyl acetate extract from the tuberous roots of P. mirifica to HAPI cells dose-dependently reduced NO production and iNOS expression induced by LPS. Attenuation of IRF-1 (interferon regulatory factor-1) induction, one of the transcription factors governing iNOS expression, suggested that the inhibitory effect on NO production by the plant extract was at least partially mediated through this transcription factor. In addition, LPS-stimulated mRNA expression of MCP-1 (monocyte chemoattractant protein-1), IL-6 (interleukin-6), and TNF-α (tumor necrosis factor-α) was also suppressed with P. mirifica extract pretreatment. This study indicates that the ethyl acetate extract of P. mirifica could potentially serve as an anti-inflammatory mediator and may be useful in relieving the severity of neurological diseases where microglia play a role.

Immunomodulatory functions of human mesenchymal stromal cells are enhanced when cultured on HEP/COL multilayers supplemented with interferon-gamma

Human mesenchymal stromal cells (hMSCs) are multipotent cells that have been proposed for cell therapies due to their immunosuppressive capacity that can be enhanced in the presence of interferon-gamma (IFN-γ). In this study, multilayers of heparin (HEP) and collagen (COL) (HEP/COL) were used as a bioactive surface to enhance the immunomodulatory activity of hMSCs using soluble IFN-γ. Multilayers were formed, via layer-by-layer assembly, varying the final layer between COL and HEP and supplemented with IFN-γ in the culture medium. We evaluated the viability, adhesion, real-time growth, differentiation, and immunomodulatory activity of hMSCs on (HEP/COL) multilayers. HMSCs viability, adhesion, and growth were superior when cultured on (HEP/COL) multilayers compared to tissue culture plastic. We also confirmed that hMSCs osteogenic and adipogenic differentiation remained unaffected when cultured in (HEP/COL) multilayers in the presence of IFN-γ. We measured the immunomodulatory activity of hMSCs by measuring the level of indoleamine 2,3-dioxygenase (IDO) expression. IDO expression was higher on (HEP/COL) multilayers treated with IFN-γ. Lastly, we evaluated the suppression of peripheral blood mononuclear cell (PBMC) proliferation when co-cultured with hMSCs on (HEP/COL) multilayers with IFN-γ. hMSCs cultured in (HEP/COL) multilayers in the presence of soluble IFN-γ have a greater capacity to suppress PBMC proliferation. Altogether, (HEP/COL) multilayers with IFN-γ in culture medium provides a potent means of enhancing and sustaining immunomodulatory activity to control hMSCs immunomodulation.

Anticytokine autoantibodies: Autoimmunity trespassing on antimicrobial immunity

Anticytokine autoantibodies can cause immunodeficiency or dysregulate immune responses. They may phenocopy genetically defined primary immunodeficiencies. We review current anti-type 1 and anti-type 2 interferon; anti-IL-12/23, anti-IL-17, and anti-GM-CSF autoantibodies; HLA associations; disease associations; and mechanistically based treatment options. Suspecting the presence of these autoantibodies in patients and identifying them at the onset of symptoms should ameliorate disease and improve outcomes.

Electrochemical Biosensors for Cytokine Profiling: Recent Advancements and Possibilities in the Near Future

Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory system, as seen in various illnesses and conditions, such as cancer, autoimmunity, neurodegeneration and other physiological disorders. Cancer and autoimmune diseases are particularly adept at developing mechanisms to escape and modulate the immune system checkpoints, reflected by an altered cytokine profile. Cytokine profiling can provide valuable information for diagnosing such diseases and monitoring their progression, as well as assessing the efficacy of immunotherapeutic regiments. Toward this goal, there has been immense interest in the development of ultrasensitive quantitative detection techniques for cytokines, which involves technologies from various scientific disciplines, such as immunology, electrochemistry, photometry, nanotechnology and electronics. This review focusses on one aspect of this collective effort: electrochemical biosensors. Among the various types of biosensors available, electrochemical biosensors are one of the most reliable, user-friendly, easy to manufacture, cost-effective and versatile technologies that can yield results within a short period of time, making it extremely promising for routine clinical testing.

Zinc Source and Concentration Altered Physiological Responses of Beef Heifers during a Combined Viral-Bacterial Respiratory Challenge

Simple Summary

Bovine respiratory disease is one of the greatest health challenges cattle producers face and is most commonly treated with antibiotics. With the current push to reduce the use of antibiotics in livestock production, producers are looking at non-pharmaceutical alternatives such as nutritional supplements. This study aimed to determine if different forms of zinc supplementation could reduce some of the negative health effects associated with bovine respiratory disease. Overall, cattle supplemented with ZinMet (zinc methionine/organic zinc) responded better during the disease as evidenced by blood parameters, decreased lesion severity, and decreased fever. Conversely, cattle fed a large dose of zinc sulfate (inorganic zinc) displayed a higher fever and blood parameters that indicated a greater sickness response. Findings from this study suggest that the type and amount of zinc fed to cattle may influence their response to bovine respiratory disease.

Abstract

To determine the effects of zinc supplementation on the immune response to a combined viral-bacterial respiratory disease challenge, thirty-two beef heifers (255 ± 15 kg) were subjected to a 30-d period of Zn depletion, then randomly assigned to one of three treatment diets fed for 30 d before the challenge: (1) supplementation with 100 mg of Zn from Zn sulfate/kg of DM (Zn100), (2) supplementation with 200 mg of Zn from Zn sulfate/kg of DM (Zn200), and (3) supplementation with 80 mg of Zn/kg of DM from zinc methionine and 20 mg of Zn from Zn sulfate/kg of DM (ZinMet). After the 30-d supplementation period, all heifers were fitted with indwelling vaginal temperature (VT) devices and intra-nasally challenged with 1 × 10⁸ PFU bovine herpesvirus-1 on d -3, and then allowed to rest in outdoor pens for 3 d. On d 0, each heifer was challenged intra-tracheally with an average dose of 2.38 × 10⁷ CFU Mannheimia haemolytica (MH), fitted with an indwelling jugular catheter, and then moved into individual stalls in an environmentally-controlled enclosed barn. Whole blood samples were collected at 1-h (serum) and 2-h (complete blood counts) intervals from 0 to 8 h, and at 12, 24, 36, 48, 60, 72, 168, and 360 h relative to MH challenge. Data were analyzed using the MIXED procedure of SAS specific for repeated measures with fixed effects of treatment, time, and their interaction. There was a treatment effect (p < 0.01) for VT such that Zn200 heifers had greater VT than Zn100 and ZinMet heifers. There was a trend (p = 0.10) for a serum cortisol treatment effect with Zn100 heifers having greater cortisol than ZinMet heifers. Total leukocytes and lymphocytes were greater (p ≤ 0.01) in Zn100 heifers than Zn200 and ZinMet heifers, whereas monocytes were less (p = 0.05) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IL-6 were greater (p = 0.02) in ZinMet heifers than Zn100 and Zn200 heifers. Concentrations of IFN-γ were greater in Zn200 heifers than ZinMet heifers at 0 h, and Zn100 heifers from 0 to 12 h post-MH challenge (treatment x time p = 0.02). Serum haptoglobin was not affected by treatment or treatment x time (p ≥ 0.36) but increased over time (p < 0.01) in all groups. There was a trend (p = 0.11) for ZinMet heifers to have less severe nasal lesion scores than Zn100 heifers. The observed differential physiological responses in this study indicate that zinc source and concentration may alter the response to a bovine respiratory challenge in heifers.

Adenovirus 7 Induces Interlukin-6 Expression in Human Airway Epithelial Cells via p38/NF-κB Signaling Pathway

Human Adenovirus (AdV) infection is very common and usually has a significant impact on children. AdV-induced inflammation is believed to be one of the main causes of severe symptoms. However, an inflammatory response profile in the airway in AdV-infected children is still lacking, and the mechanism underlying AdV-induced inflammation in the airway is also poorly understood. In the current study, we determined the expression of a panel of inflammation cytokines in the airway samples from AdV 7 infected children and further investigated the molecular mechanism underlying AdV 7-induced cytokine expression. Our results showed that eight out of 13 tested inflammatory cytokines were significantly increased in nasal washes of AdV 7-infected children comparing to healthy control, with IL-6 showing the highest enhancement. AdV 7 infection of bronchial epithelial cell line and primary airway epithelial cells confirmed that AdV 7 increased IL-6 mRNA and protein expression in an infection dose-dependent manner. Promoter analysis revealed that AdV 7 infection transactivated IL-6 promoter and a NF-κB binding site in IL-6 promoter was involved in the transactivation. Further analysis showed that upon AdV 7 infection, NF-κB p65 was phosphorylated and translocated into nucleus and bound onto IL-6 promoter. Signaling pathway analysis revealed that p38/NF-κB pathway was involved in AdV 7 infection induced IL-6 elevation. Taken together, our study shows that AdV 7 infection triggers the expression of a range of inflammatory cytokines including IL-6 in the airway of infected children, and AdV 7 enhances IL-6 expression by transactivating IL-6 promoter via p38/NF-κB signaling pathway. Findings of our current study have provided more information toward a better understanding of AdV-induced airway inflammation, which might also benefit the development of intervention strategies.

Inflammatory, cardio-metabolic and diabetic profiling of chronic schizophrenia

Background

There is a growing interest in low-grade inflammatory and metabolic alterations in patients with chronic schizophrenia (SCH).

Methods

Inflammatory (tumor-necrosis factor-α [TNF-α], interferon-γ [IFN-γ], interleukins [IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10], monocyte chemo-attractant protein-1 [MCP-1]) and growth factors (vascular endothelial growth factor [VEGF], epidermal growth factor [EGF]) were measured in blood serum samples of 105 SCH patients and 148 control subjects (CS). Simultaneously the clinical biomarkers (C-reactive protein [CRP], triglycerides [TG], low-density lipoprotein [LDL-c] and high-density lipoprotein [HDL-c] cholesterol, glycated hemoglobin [HbA1c]) were measured, and body mass index (BMI) was calculated for patients.

Results

Several cyto-/chemokines (IFN-γ, MCP-1, IL-2, IL-6, IL-8 and IL-10) were significantly (P < 0.0000001) elevated in SCH patients compared to CS. Odds ratios, obtained from logistic regression analyses, were significantly elevated for IL-2, IL-6, IL-10, INF-γ, and decreased for TNF-α in SCH group. Among the patients, higher IL-2, IL-6, INF-γ and lower MCP-1 levels as well as male gender were together significant (P < 0.000001) predictors of higher HbA1c levels, and TG/HDL-c parameter was associated with ratios of INF-γ/IL-10 (P = 0.004), and INF-γ/IL-4 (P = 0.049), HbA1c (P = 0.005), INF-γ (P = 0.009), as well as LDL-c (P = 0.02) levels.

Conclusions

IL-2, IL-6, IL-10 and IFN-γ were the most significant SCH-related markers among the measured cytokines in our patient group. Furthermore, significant associations between pro-/anti-inflammatory imbalance and HbA1c as well as cardio-metabolic risk marker (TG/HDL-c) were observed, indicating higher risks of diabetes and cardiovascular diseases among SCH patients.

Interleukin-10, Interferon Gamma, Interleukin-2, and Soluble Interleukin-2 Receptor Alpha Detected during Peritonitis in the Dialysate and Serum of Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To analyze interleukin (IL)-10, interferon gamma (IFN-y), IL-2, and soluble IL-2 receptor alpha (sIL2Rα) in the dialysate and serum of patients on continuous ambulatory peritoneal dialysis (CAPD).

Design and Patients

Samples from dialysate bags were collected during the initial month of dialysis. During peritonitis, samples were collected from the first three bags on the day of admittance to the hospital and from the night bags on days 3 and 10. Serum samples were drawn on days 1 and 10. .Results: IL-10 was detected in all dialysate samples except one on the first day of infection, with a peak median level of 50 pg/mL and a slow decrease thereafter. In serum the median levels never exceeded detectable levels. Patients infected with Escherichia coli or Staphylococcus aureus had higher IL-10 levels in dialysate on day 3 as compared to the remaining patients (p < 0.05). If the catheter had to be drawn, because of persistent cloudy dialysate, the IL-10 levels remained elevated for a longer time (p<0.05). IFN-y and IL-2were detected only in the dialysate of patients infected with either S. aureusor S. epidermidis. Only one serum sample showed increased IFN-y. SIL-2Rα was found in all the serum and dialysis samples from the first day of infection. Contrary to the analyzed cytokines, the receptor showed several fold higher levels in serum as compared to the dialysate. During the infection the receptor levels in the dialysate increased, while they remained stationary in the serum, indicating a local production.

Conclusion

This is the first time IL-10 has been demonstrated in the dialysate during peritonitis in CAPD patients. In view of its role as a suppressor of the immune and inflammatory responses, it is a potentially important observation, which might have clinical implications in the future.

Effects of Physical, Chemical, and Biological Stimulus on h-MSC Expansion and Their Functional Characteristics

Human adult mesenchymal stem or stromal cells (h-MSC) therapy has gained considerable attention due to the potential to treat or cure diseases given their immunosuppressive properties and tissue regeneration capabilities. Researchers have explored diverse strategies to promote high h-MSC production without losing functional characteristics or properties. Physical stimulus including stiffness, geometry, and topography, chemical stimulus, like varying the surface chemistry, and biochemical stimuli such as cytokines, hormones, small molecules, and herbal extracts have been studied but have yet to be translated to industrial manufacturing practice. In this review, we describe the role of those stimuli on h-MSC manufacturing, and how these stimuli positively promote h-MSC properties, impacting the cell manufacturing field for cell-based therapies. In addition, we discuss other process considerations such as bioreactor design, good manufacturing practice, and the importance of the cell donor and ethics factors for manufacturing potent h-MSC.

Ultrafine Pd nanoparticles encapsulated in microporous Co3O4 hollow nanospheres for in situ molecular detection of living cells

Recent progress in the in situ molecular detection of living cells has attracted tremendous research interests due to its great significance in biochemical, physiological, and pathological investigation. Especially for the electrochemical detection of hydrogen peroxide (H2O2) released by living cells, the highly efficient and cost-effective electrocatalysts are highly desirable. In this work, we develop a novel type of microporous Co3O4 hollow nanospheres containing encapsulated Pd nanoparticles (Pd@Co3O4). Owing to the synergy effect between the permeable microporous Co3O4 shell and the ultrafine Pd nanoparticles that encapsulated in it, the resultant Pd@Co3O4 based electrode exhibits excellent electrochemical sensor performance toward H2O2, even when the content of Pd in Pd@Co3O4 hollow nanospheres is as low as 1.14 wt %, which enable it be used for real-time tracking of the secretion of H2O2 in different types of living human cells.

High loading MnO2 nanowires on graphene paper: facile electrochemical synthesis and use as flexible electrode for tracking hydrogen peroxide secretion in live cells

Recent progress in flexible and lightweight electrochemical sensor systems requires the development of paper-like electrode materials. Here, we report a facile and green synthesis of a new type of MnO2 nanowires-graphene nanohybrid paper by one-step electrochemical method. This strategy demonstrates a collection of unique features including the effective electrochemical reduction of graphene oxide (GO) paper and the high loading of MnO2 nanowires on electrochemical reduced GO (ERGO) paper. When used as flexible electrode for nonenzymatic detection of hydrogen peroxide (H2O2), MnO2-ERGO paper exhibits high electrocatalytic activity toward the redox of H2O2 as well as excellent stability, selectivity and reproducibility. The amperometric responses are linearly proportional to H2O2 concentration in the range 0.1-45.4 mM, with a detection limit of 10 μM (S/N=3) and detection sensitivity of 59.0 μA cm(-2) mM(-1). These outstanding sensing performances enable the practical application of MnO2-ERGO paper electrode for the real-time tracking H2O2 secretion by live cells macrophages. Therefore, the proposed graphene-based nanohybrid paper electrode with intrinsic flexibility, tailorable shapes and adjustable properties can contribute to the full realization of high-performance flexible electrode material used in point-of-care testing devices and portable instruments for in-vivo clinical diagnostics and on-site environmental monitoring.

Exercise-induced increases in inflammatory cytokines in muscle and blood of horses

REASONS FOR PERFORMING STUDY

Studies have demonstrated increases in mRNA expression for inflammatory cytokines following exercise in horses and have suggested those markers of inflammation may play a role in delayed onset muscle soreness. However, measurement of mRNA expression in white blood cells is an indirect method. No studies to date have documented the cytokine response to exercise directly in muscle in horses.

HYPOTHESIS

This study tested the hypothesis that exercise increases cytokine markers of inflammation in blood and muscle.

METHODS

Blood and muscle biopsies were obtained from 4 healthy, unfit Standardbred mares (∼ 500 kg). The randomised crossover experiment was performed with the investigators performing the analysis blind to the treatment. Each horse underwent either incremental exercise test (GXT) or standing parallel control with the trials performed one month apart. During the GXT horses ran on a treadmill (1 m/s increases each min until fatigue, 6% grade). Blood and muscle biopsies were obtained 30 min before exercise, immediately after exercise and at 0.5, 1, 2, 6 and 24 h post GXT or at matched time points during the parallel control trials. Samples were analysed using real time-PCR for measurement of mRNA expression of interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-1 (IL-1). Data were analysed using t tests with the null hypothesis rejected when P < 0.10.

RESULTS

There were no changes (P > 0.10) in IL-1, IL-6, IFN-gamma or TNF-alpha during control. Exercise induced significant increases in IFN-gamma, IL1 and TNF-alpha in blood and significant increases in IFN-gamma, IL-6 and TNF-alpha in muscle. There were no significant changes in mRNA expression of IL-1 in muscle or IL-6 in blood following the GXT. These cytokine markers of inflammation all returned to preGXT levels by 24 h post GXT.

CONCLUSION

High intensity exercise results in a transient increase in the expression of inflammatory cytokines in muscle and blood.

A novel approach to induce human DCs from monocytes by triggering 4-1BBL reverse signaling

Dendritic cells (DCs) are responsible for the initiation of immune responses. Our study demonstrates a new pathway for generating a large quantity of stimulatory monocyte-derived DCs (Mo-DCs) from human monocytes using anti-4-1BB ligand (4-1BBL) mAb to trigger reverse signaling. The anti-4-1BBL-driven Mo-DCs (DCs(alpha-4-1BBL)) not only express higher levels of CD86, CD83 and HLA-DR, when compared with the Mo-DCs matured by tumor necrosis factor alpha, but also exhibit a unique phenotype that expresses lower levels of PD-L1. High levels of GM-CSF, M-CSF and Flt3 ligand (FL) were found in the anti-4-1BBL-differentiation culture. Neutralizing M-CSF, GM-CSF and FL inhibited Mo-DC proliferation stimulated by anti-4-1BBL mAb, suggesting that M-CSF, GM-CSF and FL are involved in cell proliferation stimulated by anti-4-1BBL. Further analysis of the DCs(alpha-4-1BBL) showed increased secretion of T(h)1-type cytokines IL-12 and IFN-gamma and decreased secretion of IL-10. DCs(alpha-4-1BBL) induced much stronger proliferative responses in the mixed lymphocyte reaction assay when compared with DCs derived by GM-CSF. Moreover, DCs(alpha-4-1BBL) preferentially induced T(h)1 responses. We have further demonstrated that anti-4-1BBL antibody stimulated nuclear translocation of NF-kappaB from the cytoplasm in monocytes, suggesting that reverse signaling by 4-1BBL is likely responsible for mediating DC differentiation. Collectively, we have found that reverse signaling of 4-1BBL promotes the differentiation of potent T(h)1-inducing DCs from human monocytes.

Interferon-gamma: a historical perspective

This article reviews the main lines of thinking and exploration that have led to our current conception of the role of IFN-gamma in immune defense and autoimmunity. In 1965 the first report appeared describing production of an interferon-like virus inhibitor in cultured human leukocytes following exposure to the mitogen phytohemagglutinin. In the early 1970s the active principle became recognized as being distinct from classical virus-induced interferons, leading to its designation as immune interferon or Type II interferon, and eventually IFN-gamma. Up to that point interest in the factor had come almost exclusively from virologists, in particular those among them who were believers in interferon. Evidence first coming forward in the 1980s that IFN-gamma is indistinguishable from macrophage-activating factor (MAF), then a prototype lymphokine, was the signal for immunologists at large to become interested. Today IFN-gamma ranks among the most important endogenous regulators of immune responses.

Role of cytokines in endometrium and at the fetomaternal interface

Cytokines were first recognized as factors involved in the immune responses. However, emerging evidence suggests that cytokines serve as the unanimous language through which cells in organ systems as diverse as hypothalamus to endometrium communicate. Evidence for the participation of these factors in the normal function of the endometrium and uteroplacental unit and development of the embryo is being recognized. This review will highlight the significant insight gained over the past several years for the role of cytokines in the field of reproductive biology. Major emphasis will be placed on interleukins, tumour necrosis factor-α, transforming growth factors, colony stimulating factors and interferon-gamma.

Biomarkers in exhaled breath condensate indicate presence and severity of cystic fibrosis in children

Chronic airway inflammation is present in cystic fibrosis (CF). Non-invasive inflammometry may be useful in disease management. The aim of the present cross-sectional study was to investigate: (i) the ability of fractional exhaled nitric oxide and inflammatory markers (IM) [exhaled breath condensate (EBC) acidity, nitrite, nitrate, hydrogen peroxide (H(2)O(2)), 8-isoprostane, Th1/Th2 cytokines] to indicate (exacerbations of) CF; and (ii) the ability of these non-invasive IM to indicate CF disease severity. In 98 children (48 CF/50 controls), exhaled nitric oxide was measured using the NIOX, and condensate was collected using a glass condenser. In CF interferon (IFN-gamma) and nitrite concentrations were significantly higher, whereas exhaled nitric oxide levels were significantly lower compared with controls (3.3 +/- 0.3 pg/ml, 2.2 +/- 0.2 microM, 10.0 +/- 1.2 p.p.b. vs. 2.6 +/- 0.2 pg/ml, 1.4 +/- 0.1 microM, 15.4 +/- 1.4 p.p.b. respectively). Using multivariate logistic regression models, the presence of CF was best indicated by 8-isoprostane, nitrite and IFN-gamma [sensitivity 78%, specificity 83%; area under receiver operating characteristic curve (AUC) 0.906, p < 0.001]. An exacerbation of CF was best indicated by 8-isoprostane and nitrite (sensitivity 40%, specificity 97%, AUC curve 0.838, p = 0.009). Most indicative biomarkers of CF severity were exhaled nitric oxide, and condensate acidity (sensitivity 96%, specificity 67%; AUC curve 0.751, p = 0.008). In this cross-sectional study, the combination of different exhaled IM could indicate (exacerbations of) CF, and severity of the disease in children. Longitudinal data are necessary to further confirm the role of these markers for the management of CF in children.

Immunotherapy of patients with hormone-refractory prostate carcinoma pre-treated with interferon-gamma and vaccinated with autologous PSA-peptide loaded dendritic cells--a pilot study

PURPOSE

We conducted a pilot trial to assess the feasibility and tolerability of a prime/boost vaccine strategy using interferon-gamma (IFN-gamma) and autologous dendritic cells (DCs) pulsed with HLA-A2-specific prostate-specific antigen (PSA) peptides (PSA-1 [141-150]; PSA-2 [146-156]; PSA-3 [154-163]) for the treatment of 12 patients with hormone refractory prostate carcinoma.

PATIENTS AND METHODS

All patients were vaccinated four times with intracutaneously injected PSA-peptide loaded DCs after subcutaneous administration of IFN-gamma 2 hr before DC administration (50 microg/m(2) body surface). Objectives were safety, clinical benefit, clinical and biochemical response, quality of life, and immunological parameters.

RESULTS

The vaccination was well tolerated without any vaccination-associated adverse events. One partial and one mixed responder were identified, four patients showed stable diseases. Two patients had a decrease and four a slow-down velocity slope in the PSA serum level. All responders showed a positive DTH-response, but only two a slight increase in PSA-peptide specific T-lymphocytes.

CONCLUSION

The immunotherapy with IFN-gamma and PSA-peptide loaded DCs was feasible and well tolerated. The observed responses imply a potential antitumor activity.

Effect of orange peel and black tea extracts on markers of performance and cytokine markers of inflammation in horses

This study tested the hypothesis that orange peel (O) and decaffeinated black tea (T) extracts would alter markers of exercise performance as well as exercise-induced mRNA expression for the inflammatory cytokines IL-6, TNF-alpha and IFN-gamma. Nine healthy, unfit Standardbred mares (age: 10±4years, ∼450kg) were assigned to three treatment groups in a randomized crossover design where each horse was administered one of the following; placebo (O; 21 water), black tea extract in water (T; 21) or orange peel extract in water (W; 21), via a nasogastric tube. One hour later the horses completed an incremental graded exercise test (GXT) on a treadmill at a fixed 6% grade with measurements and blood samples obtained at rest, at the end of each 1min step of the GXT and at 2 and 5min post-GXT. An additional set of blood samples for Polymerase Chain Reaction (PCR) measurements of mRNA was obtained before exercise and at 5 and 30min and 1, 2, 4 and 24h post-GXT. The GXTs were conducted between 0700 and 1200h not less than 7days apart. There were no differences (P>0.05) in VO2max, respiratory exchange ratio, run time, velocity at VO2max, core body temperature, haematocrit, creatine kinase (CK), plasma lactate concentrations, HR, right ventricular pressure (RVP) or pulmonary artery pressure (PAP) across treatments. A major finding was that orange peel extract significantly reduced post-exercise VO2 recovery time (W = 112±7, O = 86±6, and T = 120±11s). There was a significant difference in plasma total protein concentration (TP) in the O runs compared with water and T. TNF-alpha mRNA expression was lower in the T runs compared with water and O trials. IFN-gamma mRNA expression levels appeared to be lower in both the T and O extract runs compared with the water trials. The mRNA expression of IL-6 was unaltered across treatment groups. These data suggest that orange peel and black tea extracts may modulate the cytokine responses to intense exercise. Orange peel extract reduced post-exercise recovery time and may potentially enhance the ability of horses to perform subsequent bouts of high-intensity exercise.

Formulation with CpG oligodeoxynucleotides prevents induction of pulmonary immunopathology following priming with formalin-inactivated or commercial killed bovine respiratory syncytial virus vaccine

Commercial killed bovine respiratory syncytial virus (K-BRSV) and formalin-inactivated BRSV (FI-BRSV) tend to induce Th2-type immune responses, which may not be protective and may even be detrimental during subsequent exposure to the virus. In this study we assessed the ability of CpG oligodeoxynucleotides (ODNs) to aid in the generation of effective and protective BRSV-specific immune responses. Mice were immunized subcutaneously with FI-BRSV formulated with CpG ODN, Emulsigen (Em), CpG ODN and Em, or non-CpG ODN and Em. Two additional groups were immunized with K-BRSV or K-BRSV and CpG ODN. After two vaccinations, the mice were challenged with BRSV. FI-BRSV induced Th2-biased immune responses characterized by production of serum immunoglobulin G1 (IgG1) and IgE, as well as interleukin-4 (IL-4), by in vitro-restimulated splenocytes. Formulation of FI-BRSV with CpG ODN, but not with non-CpG ODN, enhanced serum IgG2a and IFN-gamma production by splenocytes, whereas serum IgE was reduced. Although the immune response induced by K-BRSV was not as strongly Th2 biased, the addition of CpG ODN to this commercial vaccine also resulted in a more Th1-type response. Furthermore, the addition of CpG ODN to the BRSV vaccine formulations resulted in enhanced neutralizing antibody responses. Significant production of IL-5, eotaxin, and eosinophilia was observed in the lungs of FI-BRSV- and K-BRSV-immunized mice. However, IL-5 and eotaxin levels, as well as the number of eosinophils, were decreased in the mice vaccinated with the CpG ODN-formulated vaccines. Finally, when formulated with CpG ODN, both FI-BRSV and K-BRSV significantly reduced virus production after challenge with BRSV.

Cellular pathology of Parkinson?s disease: astrocytes, microglia and inflammation

Parkinson's disease (PD) is a frequent neurological disorder of the basal ganglia, which is characterized by the progressive loss of dopaminergic neurons mainly in the substantia nigra pars compacta (SNpc). Inflammatory processes have been shown to be associated with the pathogenesis of PD. Activated microglia, as well as to a lesser extent reactive astrocytes, are found in the area associated with cell loss, possibly contributing to the inflammatory process by the release of pro-inflammatory prostaglandins or cytokines. Further deleterious factors released by activated microglia or astrocytes are reactive oxygen species. On the other hand, they may mediate neuroprotective properties by the release of trophic factors or the uptake of glutamate. In this review, we will discuss the different aspects of activated glial cells and potential mechanisms that mediate or protect against cell loss in PD.

Antiviral effect of Saccharomyces cerevisiae beta-glucan to swine influenza virus by increased production of interferon-gamma and nitric oxide

The aim of these experiments was to investigate the potential antiviral effect of Saccharomyces cerevisiae beta-glucan on the pneumonia induced by swine influenza virus (SIV). Forty colostrum-deprived 5-day-old piglets were randomly divided into four groups of 10. The 20 pigs in groups 1 and 2 were administered Saccharomyces cerevisiae beta-glucan orally (50 mg/day/pig; En-Bio Technology Co., Ltd) for 3 days before SIV infection and those in groups 3 and 4 were given culture medium/diluent alone. Groups 1 and 3 were inoculated intranasally with 3 ml of tissue culture fluid containing 2 x 10(6) tissue culture infective doses 50% (TCID(50))/ml of SIV and those in groups 2 and 4 were exposed in the same manner to uninfected cell culture supernatant. The microscopic lung lesions induced by SIV infection (group 1 pigs) were significantly more severe than those induced by infection in animals pre-administered beta-glucan (group 3) (P < 0.05). Significantly more SIV nucleic acid was detected in the lungs of pigs experimentally infected with SIV only (group 1) at 5, 7 and 10 days post-inoculation (dpi) compared with lungs from pigs pre-administered beta-glucan and infected with SIV (group 3) (P < 0.05). The concentrations of interferon-gamma (IFN-gamma) and nitric oxide (NO) in bronchoalveolar lavage fluid from pigs pre-administered beta-glucan and infected with SIV (group 3) were significantly higher than for any other group at 7 and 10 dpi for IFN-gamma, and at 5, 7 and 10 dpi for NO (P < 0.05). Saccharomyces cerevisiae beta-glucan reduced the pulmonary lesion score and viral replication rate in SIV-infected pigs. These findings support the potential application of beta-glucan as prophylactic/treatment agent in influenza virus infection.

Neuroinflammatory processes in Parkinson's disease

Parkinson's disease (PD) is a movement disorder characterized by the progressive degeneration of dopaminergic neurons in the midbrain. To date, its cause remains unknown and the mechanism of nerve cell death uncertain. Apart from the massive loss of dopaminergic neurons, PD brains also show a conspicuous glial reaction together with signs of a neuroinflammatory reaction manifested by elevated cytokine levels and upregulation of inflammatory-associated factors such as cyclooxygenase-2 and inducible nitric oxide synthase. Mounting evidence also suggests a possible deleterious effect of these neuroinflammatory processes in experimental models of the disease. We propose that, in PD, neuroinflammation plays a role in the cascade of events leading to nerve cell death, thus propagating the neurodegenerative process. In this review, we summarize and discuss the latest findings regarding neuroinflammatory aspects in PD.

Expression of Interferon-gamma and tumour necrosis factor-alpha in pigs experimentally infected with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)

The expression of mRNA encoding interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) was studied, by reverse transcription-polymerase chain reaction and by in-situ hybridization with a non-radioactive digoxigenin-labelled probe, in formalin-fixed, paraffin wax-embedded lung tissue from pigs experimentally infected with a Korean isolate (North American genotype) of PRRSV. Both IFN-gamma and TNF-alpha mRNA were detected in the lung as early as 1 day post-inoculation (dpi) and up to 10 dpi. Hybridization signals for IFN-gamma and TNF-alpha were usually associated with inflammation, in particular with macrophages within alveolar septa. Expression of these cytokines was minimal in non-lesional lung of PRRSV-infected pigs and in normal lung from control pigs. The results suggest that IFN-gamma and TNF-alpha play a role in pulmonary defence against PRRSV.

Regulation of estrogen activity in human endometrium: effect of IL-1beta on steroid sulfatase activity in human endometrial stromal cells

We investigated the effect of interleukin 1beta (IL-1beta) on steroid sulfatase (STS) activity and the expression of STS mRNA in human endometrial stromal cells. Endometrial tissue samples were obtained from patients undergoing hysterectomy to remove uterine fibroids. Stromal cells were isolated from the tissue preparation and cultured. IL-lbeta (1 approximately 100 ng/ml) was added into the culture medium and incubated for 24 h. The expression of STS mRNA was measured by competitive RT-PCR. The addition of IL-lbeta at 10 and 100 ng/ml suppressed STS mRNA expression to 55.2 +/- 12.8% and 25.1 +/- 10.9%, respectively, of the control sample to which no IL-lbeta had been added. STS activity was measured by radiolabelled steroid metabolite using thin layer chromatography, and this activity was also significantly suppressed in response to the administration of IL-lbeta in a dose-dependent manner. When IL-1 receptor antagonist (IL-1ra) was added together with IL-1beta to the culture medium, mRNA expression and STS activity were recovered. The present study is the first to demonstrate IL-1beta regulation of STS activity locally in human endometrium. IL-1beta suppressed mRNA and activity of STS in stromal cell culture. This initial demonstration of IL-1beta regulation of STS implies that IL-1beta may control the steroid microenvironment in human uterine endometrium by reducing biologic action of estrogen.

The porcine trophoblastic interferon-gamma, secreted by a polarized epithelium, has specific structural and biochemical properties

At the time of implantation in the maternal uterus, the trophectoderm of the pig blastocyst is the source of a massive secretion of interferon-gamma (IFN-gamma), together with lesser amounts of IFN-delta, a unique species of type I IFN. This trophoblastic IFN-gamma (TrIFN-gamma) is an unprecedented example of IFN-gamma being produced spontaneously by an epithelium. We therefore studied some of its structural and biochemical properties, by comparison with pig IFN-gamma from other sources, either natural LeIFN-gamma (from adult leucocytes), or recombinant. Biologically active TrIFN-gamma is a dimeric molecule, of which monomers are mainly composed of a truncated polypeptide chain with two glycotypes, unlike LeIFN-gamma which is formed of at least two polypeptide chains and four glycotypes. TrIFN-gamma collected in the uterus lumen was enzymatically deglycosylated and analysed by mass spectrometry (MALDI-TOF). The data revealed that the more abundant polypeptide has a mass of 14.74 kDa, corresponding to a C-terminal cleavage of 17 residues from the expected 143-residue long mature sequence. A minor polypeptide, with a mass of 12.63 kDa, corresponds to a C-terminal truncation of 36 amino acids. MALDI-TOF analysis of tryptic peptides from the glycosylated molecule(s) identifies a single branched carbohydrate motif, with six N-acetylgalactosamines, and no sialic acid. The only glycan microheterogeneity seems to reside in the number of l-fucose residues (one to three). The lack of the C-terminal cluster of basic residues, and the presence of nonsialylated glycans, result in a very low net charge of TrIFN-gamma molecule. However, the 17-residue truncation does not affect the antiproliferative activity of TrIFN-gamma on different cells, among which is a porcine uterine epithelial cell line. It is suggested that these specific properties might confer on TrIFN-gamma a particular ability to invade the uterine mucosa and exert biological functions beyond the endometrial epithelium.

Genes expressed during the IFN gamma-induced maturation of pre-B cells

Interferon-gamma (IFN gamma) exerts diverse responses in B cell development ranging from growth arrest and apoptosis to proliferation and differentiation. IFN gamma stimulates murine 70Z/3 pre-B cells to express surface immunoglobulin (Ig) and this system serves as a useful model for the pre-B to immature B cell transition in B cell development. To analyze this developmental transition, we used a PCR-based subtractive hybridization in combination with miniarray screening to identify differentially-expressed genes in IFN gamma-stimulated compared with unstimulated 70Z/3 pre-B cells. The majority (44%) of the differentially-expressed genes obtained were known IFN gamma-inducible. These included multiple isolates from each of three multi-gene families, including two guanylate-binding protein (47 and 67kDa GBP) families of GTPases and the hematopoietic IFN gamma-inducible nuclear protein family (HIN-200). These multiple isolates of genes comprised the majority of the total isolated and sequenced clones. Other known IFN gamma-induced genes in this group included Ig kappa light chain and Ly-6, as well as genes with functions in antigen processing, cellular regulation, and cytoskeletal organization. Another 36% of the genes identified were previously known, but not known to be IFN gamma-inducible (e.g. pre-B cell enhancing factor, PBEF). The remaining 20% of the IFN gamma-induced isolates did not match entries in Genbank, and thus, may represent novel genes involved in IFN gamma responses and/or in the pre-B to immature B cell transition. Overall, the majority of the individual genes isolated were either not known to be IFN gamma responsive or were not previously known.

Establishment of a cytokine-producing anaplastic large-cell lymphoma cell line containing the t(2;5) translocation: potential role of cytokines in clinical manifestations

A permanent cell line, HSC-M1, was established from a child with advanced CD30 (Ki-1)+ anaplastic large-cell lymphoma (ALCL). Clinical features included irritability, fever, weight loss, tender lymphadenopathy, pneumonitis, neutrophilia, and bone marrow erythrophagocytosis. While HSC-M1 cells exhibited an immunophenotype characteristic of ALCL of T-cell lineage, the cell line also demonstrated features of monocyte-macrophage lineage. Cytogenetic and polymerase chain reaction (PCR) analysis of the HSC-M1 cell line and involved bone marrow demonstrated the characteristic non-random chromosomal translocation t(2:5)(p23:q35). Reverse transcriptase PCR for mRNA expression of cytokines and cytokine receptors showed that HSC-M1 cells expressed the message for multiple cytokines and their receptors. Measurement of cytokine levels in serum samples using enzyme-linked immunosorbent assays showed increased concentrations of several cytokines. The increased levels of some cytokines correlated with disease activity and clinical symptoms. Although spontaneous production by HSC-M1 cells of some of these cytokines was demonstrated, the production of others was only detectable after stimulation with exogenous CD30 ligand. With few exceptions, there was good correlation between serum cytokine levels and cytokines produced by HSC-M1 cells. These findings indicate that cytokine production is a feature of ALCL cells and that some of the clinical manifestations in ALCL may result from cytokines produced by either the malignant or accessory cells.

Interferon-gamma down-regulates gene expression of cathepsin K in osteoclasts and inhibits osteoclast formation

The cytokine, IFN-gamma, has been shown in vitro to inhibit bone resorption, but the mechanisms responsible for this inhibition have not been clearly defined. Cathepsin K is a major protease responsible for bone resorption. IFN-gamma may inhibit bone resorption through down-regulation of osteoclast genes, including cathepsin K. To test the hypothesis, we investigated the effect of IFN-gamma on cathepsin K expression in the MOCP-5 and wild-type mouse bone marrow co-culture systems by Northern blot as well as osteoclast formation at different stages of differentiation. The results show that IFN-gamma down-regulates mRNA levels of cathepsin K in a time- and dose-dependent manner. Consequently, cathepsin K protein production is also reduced by IFN-gamma. Moreover, our results indicate that IFN-gamma inhibits osteoclast formation only early in osteoclast differentiation. IL-6 and TNFalpha did not significantly affect cathepsin K gene expression in osteoclasts. However, IL-1alpha stimulated gene expression. In conclusion, our data suggest that the actions of IFN-gamma on osteoclastic bone resorption may be mediated by its effects on both osteoclast formation at an early stage and osteoclast gene expression in mature osteoclasts.

In vitro and in vivo enhancement of canine pulmonary alveolar macrophage cytotoxic activity against canine osteosarcoma cells

The combination of chemotherapy with immunotherapy may offer an advantage over either therapy alone and provide a greater potential for total tumor eradication. Monocyte/macrophage-mediated tumor cell killing is a major mechanism of the host's defense against primary and/or metastatic neoplasia. We evaluated the tumoricidal activity against canine osteosarcoma cells of canine pulmonary alveolar macrophages (PAM) exposed in vitro to two recombinant canine (rc) cytokines (rcTNF alpha and rcIFN gamma). We also evaluated the in vivo tumoricidal activity of PAM from dogs treated with the macrophage activator, liposome-encapsulated muramyl tripeptide-phosphatidyl-ethanolamine (L-MTP-PE) alone or in combination with doxorubicin (DOX). This study demonstrated that rcTNF alpha and rcIFN gamma significantly enhance in vitro canine PAM cytotoxicity against canine osteosarcoma cells, and that PAM from dogs treated with DOX + L-MTP-PE have enhanced cytotoxic activity against osteosarcoma cells when compared to dogs treated with DOX or L-MTP-PE alone. These findings support the rationale for combining a chemotherapy agent with an immunotherapy agent for the treatment of metastatic disease, and suggest a role for TNF alpha and IFN gamma as agents for stimulating the antitumor activity of macrophages.

Enhanced clearance of a multiple antibiotic resistant Staphylococcus aureus in rats treated with PGG-glucan is associated with increased leukocyte counts and increased neutrophil oxidative burst activity

PGG-Glucan [Betafectin], a highly purified soluble beta-(1-6)-branched beta-(1 3)-linked glucan isolated from Saccharomyces cerevisiae, has broad in vitro and in vivo anti-infective activities unrelated to cytokine induction. Here we present in vivo results on the anti-infective activity of PGG-Glucan against a multiple antibiotic resistant Staphylococcus aureus. PGG-Glucan (0.25-4 mg/kg) was administered intramuscularly to male Wistar rats 48 h, 24 h, and 4 h before and 4 h after intraperitoneal implantation of a gelatin capsule containing 10(8)S. aureus colony forming units (CFU). Blood samples were collected at various times after challenge to determine CFU levels, leukocyte counts and neutrophil oxidative burst activity; serum TNF-alpha, and IL-1beta levels were also evaluated. The 0.25 mg/kg PGG-Glucan dose had no effect on reducing blood CFU levels; however, PGG-Glucan doses of 0.5 mg/kg, 1 mg/kg, 2 mg/kg or 4 mg/kg significantly reduced blood CFU levels by 48 h after challenge. Reduced CFU levels correlated with significantly elevated absolute monocyte counts, absolute neutrophil counts, and neutrophil oxidative burst activity in the absence of any effect on TNF-alpha or on IL-1beta levels. In additional studies, effects on mortality and blood CFU levels were evaluated in rats treated with ampicillin (an antibiotic to which the S. aureus was resistant), PGG-Glucan, or both agents. Mortality and blood CFU levels were reduced most in combination-treated rats compared to saline control rats or rats treated with either ampicillin alone or PGG-Glucan alone. We conclude that in vivo (1) PGG-Glucan can enhance clearance of an antibiotic resistant S. aureus, (2) that this clearance is accompanied by an increase in monocytes and neutrophils as well as a potentiation of neutrophil oxidative microbiocidal activity without alteration of the proinflammatory cytokine response, and (3) PGG-Glucan can enhance the effectiveness of traditional antibiotic treatment.

Vaccinia virus-encoded cytokine receptor binds and neutralizes chicken interferon-gamma

To counteract the host immune response, poxviruses have evolved secreted factors that bind cytokines and thereby neutralize their biological activities. The vaccinia virus B8R gene encodes a protein that neutralizes interferon-gamma (IFN-gamma) from several mammals including man, cow, rat, and rabbit but not mice. We now report that the activity of the B8R gene product is not restricted to cytokines of mammals: it also efficiently neutralized chicken IFN-gamma. B8R blocked chicken IFN-gamma-mediated induction of guanylate binding protein RNA in the chicken fibroblast cell line CEC-32 and secretion of nitric oxide in HD-11 cells. Radiolabeled baculovirus-expressed B8R efficiently bound to immobilized recombinant chicken IFN-gamma. Scatchard analysis revealed a binding constant of chicken IFN-gamma to B8R of approximately 0.5 nM. A mutant form of chicken IFN-gamma which lacks the 18 C-terminal amino acids and which has lost more than 99% of its biological activity was able to block the IFN-gamma-neutralizing effect of B8R. Binding studies showed that the mutant protein bound radiolabeled B8R only about threefold less well than wild-type chicken IFN-gamma but failed to compete with wild-type chicken IFN-gamma for binding to the cellular receptor. These results suggest that the extreme C terminus of chicken IFN-gamma is crucial for binding to its cellular receptor but less important for recognition by the viral cytokine receptor.

Application of free-flow electrophoresis for isolation and purification of proteins and peptides

Free-flow electrophoresis (FFE) has been applied to the separation and purification of a variety of proteins and polypeptides: bee venom, tumor necrosis factor, interleukin-1beta, interferon-gamma and superoxide dismutase. FFE at constant pH and conductivity of the carrying buffer is shown to be efficient at various separation schemes. In some cases, the method allows us to obtain proteins with a purity of more than 90% at a productivity of 20-30 mg/h. An electrophoretic apparatus with a new, multi-sectional construction of the electrophoretic chamber and a system for cross-displacement of carrying buffer in the chamber is described.

Cytokines and cell adhesion molecules in cerebral ischemia: experimental bases and therapeutic perspectives

The possibility of reopening an occluded cerebral artery by means of thrombolysis has renewed interest in a number of the several mechanisms that are active during acute cerebral ischemia. Over recent years, it has become apparent that leukocytes play a central role not only during the healing stage of brain infarction but also during the early phases of cerebral ischemia, when it is postulated that these cells produce harmful effects, particularly in the presence of reperfusion. This review is based on the critical analysis of more than 150 publications dealing with the role of leukocytes and some inflammatory mediators (cytokines, chemokines, and adhesion molecules) in cerebral ischemia. Animal studies indicate that leukocyte involvement is promoted by a variety of inflammatory molecules produced immediately after the onset of cerebral ischemia. Considerable experimental evidence suggests that these mediators play a key role in the progression from ischemia to irreversible injury (ie, cellular death and necrosis). However, the precise role of each molecule alone remains to be further elucidated as well as in relation to the complex network existing among different mediators. Progress in our understanding of the inflammatory mechanisms operating in cerebral ischemia has enabled the testing of new compounds with promising results in animals; in contrast, one recent controlled trial of an anti-leukocyte molecule in acute stroke patients showed negative results. This discrepancy may derive in part from our incomplete understanding of the complexity of the inflammatory mechanisms involved in cerebral ischemia. Our analysis suggests that until sufficient knowledge of the underlying disease mechanisms is acquired, more care should be taken when testing new and potentially efficacious drugs in stroke patients.

Pneumocystis carinii induces ICAM-1 expression in lung epithelial cells through a TNF-alpha-mediated mechanism

Inflammatory cell recruitment contributes to respiratory impairment during Pneumocystis carinii pneumonia. We evaluated expression of intercellular adhesion molecule-1 (ICAM-1), a key participant in leukocyte accumulation, in rats with P. carinii pneumonia. Immunostaining for ICAM-1 was most marked on bronchiolar epithelium but was also evident on type II pneumocytes, endothelium, and macrophages. Lung from normal and dexamethasone-treated uninfected animals exhibited markedly less ICAM-1. We hypothesized that P. carinii promoted ICAM-1 expression in epithelium through tumor necrosis factor-alpha (TNF-alpha) release from macrophages or that P. carinii directly stimulated ICAM-1 expression. Alveolar macrophages were incubated with P. carinii, and the medium was added to A549 epithelial cells. Treatment of macrophages with P. carinii enhanced A549 ICAM-1, which was inhibited with antibody to TNF-alpha. To determine whether P. carinii alone also stimulated ICAM-1, A549 cells were cultured with P. carinii, also augmenting ICAM-1. Of note, A549 ICAM-1 expression from P. carinii alone was less than with P. carinii-exposed macrophages. Thus ICAM-1 is enhanced in lung epithelium during P. carinii infection, in part, through TNF-alpha-mediated mechanisms.

Interleukin-13 secretion by normal and posttransplant T lymphocytes; in vitro studies of cellular immune responses in the presence of acute leukaemia blast cells

T lymphocyte secretion of interleukin-13 (IL-13) in response to different activation signals was characterized in vitro. IL-13 release was investigated when virus transformed B lymphocytes or acute myelogenous leukaemia (AML) blasts were used as accessory cells during T cell activation. First, a majority of both CD4+ and CD8+ TCR alpha beta + T lymphocyte clones, derived from normal individuals and bone marrow transplant recipients, secreted IL-13 in response to a standardized mitogenic activation signal (phytohaemagglutinin + IL-2 + B lymphocyte accessory cells). The CD4+ cells showed significantly higher IL-13 levels than the CD8+ subsets. Second, when leukaemic accessory cells (more than 95% AML blasts) were used during T cell activation, IL-13 was released both during alloactivation of normal T lymphocytes and during mitogen activation of posttransplant T cells. Third, when normal T lymphocytes were stimulated with allogeneic AML blasts, addition of IL-13-neutralizing monoclonal antibodies decreased interferon gamma levels. Although addition of IL-13-neutralizing antibodies did not alter granulocyte-colony-stimulating factor secretion by allostimulating AML blasts, altered blast proliferation was detected for certain patients. Thus, most T cell clones can release IL-13, and IL-13 can modulate cytokine responses during T cell recognition of allogeneic AML cells.

Osteochondrodysplasia occurring in transgenic mice expressing interferon-gamma

In addition to various biological activities, interferon-gamma (IFN-gamma) inhibits bone resorption and collagen synthesis. We produced a transgenic mouse line expressing the murine IFN-gamma gene and protein in the bone marrow and thymus. Forty-five transgenic FVB/NCr mice, 23 days-9 months of age, were studied for anomalies in the skeletal system. The transgenic mice had short, wide, and deformed long bones. Young transgenic mice had epiphyseal plates severely thickened with zones of hypertrophy and degeneration with irregular metaphyseal borders. Cartilagenous masses were also observed in the metadiaphyseal marrow cavities. These lesions were primarily seen in long bones and ribs. Adult transgenic mice had residues of degenerated cartilagenous masses in the diaphyses. Many osteoclasts with well-developed ruffled borders were present on the metaphyseal cartilagenous masses in young transgenic mice. Adult transgenic mice had less prominent primary spongiosa with fewer osteoclasts at the metaphysis as compared with nontransgenic controls. The cortical bones of the transgenic mice were thinner and more immature compared with controls. Transgenic mice also had fractures, disruption of the epiphyseal plate, and degeneration of articular cartilage. Thus, the IFN-gamma transgenic mice developed a complex chondro-osseous lesion that was diagnosed as osteochondrodysplasia. The lesions may originate from primarily decreased matrix synthesis in bone and cartilage and also possible osteoclast-related changes caused by IFN-gamma overexpression in the bone marrow. Our IFN-gamma transgenic mouse will be a useful model to investigate the role of IFN-gamma in bone metabolism.

Human disease associated with Clostridium perfringens enterotoxin

Clostridium perfringens continues to be a common cause of food-borne disease. Characteristics of this organism that contribute to its ability to cause food-borne illness include the formation of heat-resistant spores that survive normal cooking/heating temperatures, a rapid growth rate in warm food, and the production of enterotoxin (CPE) in the human gut. Time and temperature abuse associated with food preparation contributes to the majority of outbreaks of C. perfringens food-borne disease. CPE-induced diarrhea has been reported in the absence of a defined food vehicle. These cases have been typically associated with the elderly and following a course of antibiotic therapy. The incidence of CPE-induced diarrhea may be expected to increase with the growing population of immunocompromised (disease-, treatment-, or age-induced) individuals. Clostridium perfringens has been implicated as a possible contributor to the development of SIDS in susceptible individuals. Specifically, it has been hypothesized that CPE acts as a triggering agent, initiating the events associated with the development of SIDS. Continued refinement of both immunoassays and molecular methods for toxin and gene detection, respectively, will facilitate their eventual availability as commercial kits, providing rapid and simplified methods for the detection of C. perfringens isolates that produce or have the capacity to produce CPE as well as other toxins associated with this organism.

Effects of methyl mercury on cytokines, inflammation and virus clearance in a common infection (coxsackie B3 myocarditis)

A myocarditic coxsackievirus B3 (CB3) infection in Balb/c mice was used to investigate the effects of 12 weeks of methyl mercury (MeHg) exposure (3.69 mg/g diet) on inflammatory heart lesions, virus in the heart, the cytokine response, i.e. cachectin/TNF-alpha and gamma-interferon (IFN-gamma) levels in plasma, and on disease complications and mortality. This dose of MeHg did not influence mortality in this infection model. The inflammatory and necrotic lesions in the ventricular myocardium 7 days after the inoculation covered 2.2% of the tissue section area in infected control mice. This damage was increased (n.s.) by 50% (to 3.3% of the tissue section area) in MeHg-treated mice. The response pattern of lymphocyte subsets in situ in myocardial inflammatory lesions was corroborated using an immune histological technique. MeHg treatment tended to increase (2.2-fold, n.s.) the number of Mac 2+ cells (macrophages) in the heart muscle in this infection. Plasma levels of both TNF-alpha and IFN-gamma increased on day 3 of the infection in MeHg-treated as well as in non-MeHg-treated mice, but the mean IFN-gamma response was more pronounced in the MeHg-treated mice. On day 7 of the infection, when most animals still showed clinical signs of disease, cytokine levels were back to normal. MeHg-exposure in non-infected mice did not affect cytokine levels. In situ hybridization of virus RNA in myocardial tissue showed remaining virus in those mice who had the lowest plasma IFN-gamma levels. A 20% increased (P < 0.05) lymphoproliferative response to the T cell mitogen Con A was observed as a result of the MeHg treatment. Even heart tissue lesions and virus persistence tended to be influenced by MeHg in a direction compatible with the development of chronic disease.

Biological properties of recombinant chicken interferon-gamma

Supernatants of the chicken T cell line 855 contain antiviral and macrophage activating factor activity and strongly activate transcription of the guanylate binding protein (GBP) gene in chicken cells. To characterize the cytokine responsible for the GBP-inducing activity, we chose a cDNA expression cloning strategy in COS cells. Sequencing a positive clone revealed that it encode chicken interferon-gamma (ChIFN-gamma). Histidine-tagged ChIFN-gamma was expressed in Escherichia coli and purified by nickel chelate affinity chromatography. ChIFN-gamma from COS cells and E. coli both potently induced GBP RNA synthesis but were rather poor antiviral agents. In macrophages, recombinant ChIFN-strongly stimulated secretion of nitric oxide and enhanced expression of major histocompatibility complex class II antigen. A rabbit antiserum to E. coli derived ChIFN-gamma effectively neutralized the macrophage-activating factor activity secreted by concanavalin A-induced spleen cells and various T cell lines, suggesting that IFN-gamma is the major macrophage-activating factor of the chicken.

Interferon-gamma enhances megakaryocyte colony-stimulating activity in murine bone marrow cells

We have demonstrated previously that interferon-gamma (IFN-gamma) accelerates platelet recovery in mice with 5-FU induced-marrow aplasia in vivo. However, the mechanism for the regulation of megakaryocyte development induced by IFN-gamma in bone marrow cells in vivo remains unknown. To further study the effects of IFN-gamma on megakaryocyte development, various steps during IFN-gamma-mediated accelerated differentiation of the megakaryocytes were investigated in serum-free cultures of murine bone marrow cells in vitro. IFN-gamma markedly induced acetylcholine esterase (AChE) activity, a marker of murine megakaryocytic cells, accompanied by increased colony formation of the megakaryocyte lineage. A prominent increase in megakaryocyte number was observed after IFN-gamma treatment. All of these effects were dependent on the presence of IL-3, and, therefore, these results suggest that IFN-gamma acts as a megakaryocyte potentiator (Meg-POT). However, IFN-gamma did not enhance megakaryocyte maturation with respect to increase in cell size. The effects of IFN-gamma on megakaryocyte maturation were similar to those observed after treatment with higher doses of IL-3 alone. Meg-POT is defined as a factor that induces megakaryocyte maturation. Since IFN-gamma enhanced IL-3-dependent megakaryocyte colony formation and proliferation rather than megakaryocyte maturation, the effects on megakaryocyte development, which were induced by IFN-gamma treatment, seem to be different from the effects of a Meg-POT. We, therefore, propose a new function for IFN-gamma as an enhancer of megakaryocyte colony-stimulating factor activity. The effect of IFN-gamma in vitro appears to correlate well with the acceleration of platelet recovery in vivo.

In vitro lymphocyte blastogenic responses and cytokine production in sickle cell disease patients with acute pneumonia

BACKGROUND

Pulmonary infections continue to be a major cause of morbidity and mortality in patients with sickle cell disease (SCD).

METHODS

In this study cell-mediated immunity in vitro was evaluated in 62 SCD patients (62 steady state and 16 with acute pneumonia) and compared with 44 normal controls (30 healthy and 14 with acute pneumonia). Lymphocyte blastogenic responses to phytohemagglutinin, tetanus toxoid and Candida albicans antigen were assessed in all subjects. In addition production of tumor necrosis factor, alpha- and gamma-interferon (IFN) were assayed.

RESULTS

The results revealed comparable blastogenic responses to all three stimuli in all subjects except SCD patients with pneumonia. This group showed poor responses to all stimuli. The mean counts per minute were decreased 65 to 90% when compared with the other patients. Cytokine production of IFN-alpha and TNF was equivalent in all subjects. Conversely IFN-gamma production in both SCD groups, steady state (35 +/- 6 U/ml) and SCD with pneumonia (14 +/- 6 U/ml), was significantly decreased when compared with those in normal healthy controls (65 +/- 14 U/ml) and with pneumonia (48 +/- 17 U/ml). On analysis of individual titers 15 of 62 (24%) steady state and 10 of 16 (63%) SCD patients with pneumonia were deficient in IFN-gamma production in vitro.

CONCLUSIONS

Acute pulmonary infections seem to have a profound effect on cell-mediated immunity in SCD. IFN-gamma deficiency, along with quantitative and qualitative T cell abnormalities, may represent significant factors to explain the frequent and severe infections seen in SCD.