An overview of the immune system

Monocyte number associated with incident cancer and mortality in middle-aged and elderly community-dwelling Danes

BACKGROUND

Monocytes play an important role in innate immunity and exhibit prognostic value in some cancers. It was hypothesised that activation of the innate immune system through mobilisation of monocytes to tissue macrophages develops an inflammatory state associated with increased risk of cancer and mortality.

METHODS

To test this hypothesis monocyte number was measured in a sample of 669 Danish men (59%) and women (41%) aged 55 to 75 years who were free of any known prevalent cancer or cardiovascular disease. The population was followed for 6.3 years, during which period incident cancers and deaths were compiled from validated national registries.

RESULTS

Fifty-two subjects developed cancer and 83 subjects died during follow-up. The upper quintile of monocyte number (median 0.44×10⁹/L, lower quintile <0.33, upper quintile >0.60) was associated with an increased risk of cancer (hazard ratio [HR] 2.00 [95% CI 1.12-3.57]) and deaths (HR 1.67 [1.03-2.72]) in univariate analyses, after correction for age and gender (cancer HR 2.15 [1.20-3.86] and death HR 1.63 [1.00-2.67]), and following additional correction for smoking habits, diabetes, systolic blood pressure, and total cholesterol (cancer HR 2.00 [1.10-3.70] and death HR 1.30 [0.78-2.16]). COX regression models, with inclusion of the aforementioned explanatory variables and added heart rate variability, alcohol use, and CRP, revealed monocyte count (per 0.1×10⁹/L increase) to be independently associated with incident cancer (HR 1.12 (1.05-1.19)) and death (HR 1.13 (1.06-1.19)).

CONCLUSIONS

In healthy middle-aged and elderly community-dwelling Danes circulating monocytes independently predicted incident cancer and mortality.

Increased expression of interleukin-6 family members and receptors in urinary bladder with cyclophosphamide-induced bladder inflammation in female rats

Recent studies suggest that janus-activated kinases-signal transducer and activator of transcription signaling pathways contribute to increased voiding frequency and referred pain of cyclophosphamide (CYP)-induced cystitis in rats. Potential upstream chemical mediator(s) that may be activated by CYP-induced cystitis to stimulate JAK/STAT signaling are not known in detail. In these studies, members of the interleukin (IL)-6 family of cytokines including, leukemia inhibitory factor (LIF), IL-6, and ciliary neurotrophic factor (CNTF) and associated receptors, IL-6 receptor (R) α, LIFR, and gp130 were examined in the urinary bladder in control and CYP-treated rats. Cytokine and receptor transcript and protein expression and distribution were determined in urinary bladder after CYP-induced cystitis using quantitative, real-time polymerase chain reaction (Q-PCR), western blotting, and immunohistochemistry. Acute (4 h; 150 mg/kg; i.p.), intermediate (48 h; 150 mg/kg; i.p.), or chronic (75 mg/kg; i.p., once every 3 days for 10 days) cystitis was induced in adult, female Wistar rats with CYP treatment. Q-PCR analyses revealed significant (p ≤ 0.01) CYP duration- and tissue- (e.g., urothelium, detrusor) dependent increases in LIF, IL-6, IL-6Rα, LIFR, and gp130 mRNA expression. Western blotting demonstrated significant (p ≤ 0.01) increases in IL-6, LIF, and gp130 protein expression in whole urinary bladder with CYP treatment. CYP-induced cystitis significantly (p ≤ 0.01) increased LIF-immunoreactivity (IR) in urothelium, detrusor, and suburothelial plexus whereas increased gp130-IR was only observed in urothelium and detrusor. These studies suggest that IL-6 and LIF may be potential upstream chemical mediators that activate JAK/STAT signaling in urinary bladder pathways.

From vaccine practice to vaccine science: the contribution of human immunology to the prevention of infectious disease

Over the past 50 years, the practice of vaccination has reached the important goal of reducing many of the diseases that afflicted humanity in past centuries. A better understanding of immunological mechanisms underlying the induction of immune protection and the advent of new technology led to improved vaccine preparations based on purified microbial antigens and new adjuvants able to boost both humoral and cellular immune responses. Despite these tremendous advances, much remains to be done. The emergence of new pathogens, the spread of strains resistant to antibiotics and the enormous increase in latent infections are urgently demanding more and more effective vaccines. Understanding the immunological mechanisms that mediate resistance against infections would certainly provide valuable information for the design of new candidate vaccines.

A short overview of vitamin C and selected cells of the immune system

Vitamin C (ascorbic acid) is an essential water-soluble nutrient that primarily exerts its effect on a host defense mechanisms and immune homeostasis and is the most important physiological antioxidant. Stable intake of vitamin C is essential for life in humans because the body does not synthesize it. Even the numerous studies have demonstrated that vitamin C supplementation stimulates the immune system, prevents DNA damage and significantly decreases the risk of a wide range of pathologies; the potential protective mechanisms are still largely unknown. This review summarizes the recently known facts about the role of vitamin C on the selected cells of the immune system and potential molecular mechanisms involved. Further, in this review, many new data about the positive effects of vitamin C on the immune system, potential toxicological effects, vitamin C supplementation in disease development, as well as some proposed mechanisms of vitamin C activity, are discussed.

1α,25-Dihydroxyvitamin D3 and all-trans retinoic acid synergistically inhibit the differentiation and expansion of Th17 cells

1α,25-Dihydroxyvitamin D(3) (1,25D3), the active form of vitamin D(3), is an immunoregulatory hormone with beneficial effects on Th1 cell-mediated inflammatory diseases. Although IL-17-producing CD4(+) T helper (Th17) cells have been recently identified as novel effector cells, the immunomodulating effects of 1,25D3 on Th17 cells have not been well defined. We confirmed here that 1,25D3 inhibited the generation of Th17 cells in vitro. Interestingly, 1,25D3 synergistically suppressed the generation of Th17 cells by the combination with all-trans retinoic acid (ATRA). 1,25D3 and ATRA suppressed the development of allergen-induced contact hypersensitivity (CHS) in a mouse ear swelling model. In addition, we found that 1,25D3 and ATRA significantly inhibited the development of human Th17 cells from both naïve and memory human CD4(+) T cells. 1,25D3 and ATRA effectively suppressed mRNA expressions of IL-1R1, IL-21R, IL-23R, RORC, and AHR in human T cells. ATRA further suppressed IL-6R, whereas 1,25D3 did not. Finally, we found that 1,25D3 and ATRA remarkably blocked IL-22 as well as IL-17 mRNA expression in human memory CD4(+) T cells. Thus, we initially reveal that 1,25D3 and ATRA have synergistic effects on the generation of Th17 cells, suggesting that the combination with ATRA would provide a promising novel therapy for Th17 cell-related immune diseases including skin inflammation.

Impact of product-related factors on immunogenicity of biotherapeutics

All protein therapeutics have the potential to be immunogenic. Several factors, including patient characteristics, disease state, and the therapy itself, influence the generation of an immune response. Product-related factors such as the molecule design, the expression system, post-translational modifications, impurities, contaminants, formulation and excipients, container, closure, as well as degradation products are all implicated. However, a critical examination of the available data shows that clear unequivocal evidence for the impact of these latter factors on clinical immunogenicity is lacking. No report could be found that clearly deconvolutes the clinical impact of the product attributes on patient susceptibility. Aggregation carries the greatest concern as a risk factor for immunogenicity, but the impact of aggregates is likely to depend on their structure as well as on the functionality (e.g., immunostimulatory or immunomodulatory) of the therapeutic. Preclinical studies are not yet capable of assessing the clinically relevant immunogenicity potential of these product-related factors. Simply addressing these risk factors as part of product development will not eliminate immunogenicity. Minimization of immunogenicity has to begin at the molecule design stage by reducing or eliminating antigenic epitopes and building in favorable physical and chemical properties.

In vitro and in vivo interactions of aluminum on NTPDase and AChE activities in lymphocytes of rats

Al adjuvants are used in vaccines to increase the immune response. NTPDase and AChE play a pivotal role and act in the regulation of the immune system. The effect of Al exposure in vitro and in vivo on NTPDase and AChE activities in the lymphocytes of rats was determined. In vitro, ATP hydrolysis was decreased by 20.4% and 17.3% and ADP hydrolysis was decreased by 36.5% and 34.8%, in groups D and E, respectively, when compared to the control. AChE activity was increased by 157.3%, 152.5%, 74.7% and 90.8% in groups B, C, D, and E, respectively, when compared to the control. In vivo, ATP hydrolysis was increased by 85% and 86% and ADP hydrolysis was increased by 104.2% and 74%, in Al plus citrate and Al groups, respectively, when compared to the control. AChE activity was increased by 50.7% in Al plus citrate and by 28.6% in Al groups, when compared to the control. Our results show that Al exposure both in vitro and in vivo altered NTPDase and AChE activities in lymphocytes. These results may demonstrate the ability of Al to elicit the immune system, where NTPDase and AChE activities can act as purinergic and cholinergic markers in lymphocytes.

Biological therapy of bone defects: the immunology of bone allo-transplantation

IMPORTANCE OF THE FIELD

Bone is one of the most transplanted tissues worldwide. Autograft is the ideal bone graft but is not widely used because of donor site morbidity and restricted availability. Allograft is easily accessible but can transmit infections and elicit an immune response.

AREAS COVERED IN THIS REVIEW

This review identifies all in vitro and in vivo evidence of immune responses following bone transplantation and highlights methods of improving host tolerance to bone allotransplantation.

WHAT THE READER WILL GAIN

In humans, the presence of anti-HLA specific antibodies against freeze-dried and fresh-frozen bone allografts has been demonstrated. Fresh-frozen bone allograft can still generate immune reactions whilst freeze-dried bone allografts present with less immunogenicity but have less structural integrity. This immune response can have an adverse effect on the graft's incorporation and increase the incidence of rejection. Decreasing the immune reaction against the allograft by lowering the immunogenic load of the graft or lowering the host immune response, would result in improved bone incorporation.

TAKE HOME MESSAGE

It is essential that the complex biological processes related to bone immunogenicity are understood, since this may allow the development of safer and more successful ways of controlling the outcome of bone allografting.

Essential role of vitamin C and zinc in child immunity and health

With the progressive elimination of dietary protein-energy deficits, deficiencies of micronutrients are emerging as the limiting factors in ensuring children's optimal health. Data from several countries in Asia and Latin America indicate that deficiencies of vitamin C and zinc continue to be at alarming levels. This article reviews the roles of vitamin C and zinc in supporting children's growth and development, with a particular focus on the complementary roles they play in supporting immune functions and combating infections. The contemporary relevance of vitamin C and zinc deficiency in the Asian and Latin American regions, both undergoing a rapid nutritional transition, are also discussed. Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defences. Nutrition should be the main vehicle for providing these essential nutrients; however, supplementation can represent a valid support method, especially in developing regions.

Smoking and atherosclerotic cardiovascular disease: Part I: atherosclerotic disease process

The normal endothelium inhibits platelet and leukocyte adhesion to the vascular surface maintaining a balance of profibrinolytic and prothrombotic activity. Endothelial function is assessed largely as endothelium-dependent vasomotion, partly based on the assumption that impaired endothelium-dependent vasodilation reflects the alteration of important endothelial functions. Atherosclerotic risk factors, such as hypercholesterolemia, hypertension, diabetes and smoking, are associated with endothelial dysfunction. In the diseased endothelium, the balance between pro- and antithrombotic, pro- and anti-inflammatory, pro- and antiadhesive or pro- and antioxidant effects shifts towards a proinflammatory, prothrombotic, pro-oxidative and proadhesive phenotype of the endothelium. A common mechanism underlying endothelial dysfunction is related to the increased vascular production of reactive oxygen species. Recent studies suggest that inflammation per se, and C-reactive protein in particular, may contribute directly to endothelial dysfunction. The loss of endothelial integrity is a hallmark of atherosclerosis and the causal possible link between each individual risk factor, the development of atherosclerosis and the subsequent clinical events, such as myocardial infarction or stroke.

Emerging drugs to treat Crohn's disease

IMPORTANCE OF THE FIELD

Inflammatory bowel diseases are chronic inflammatory diseases that comprise of two forms - Crohn's disease (CD) and ulcerative colitis (UC) - characterized by aberrant responses to luminal bacteria in genetically susceptible individuals. Whereas inflammation is limited to the large intestine in patients with UC, CD can affect all parts of the gastrointestinal tract. During disease exacerbations, pharmacological or surgical intervention is usually needed to re-establish remission; however, current therapeutic interventions cannot cure CD. As a subgroup of patients with CD will not be able to remain in remission with available drugs or suffer from side effects, new therapeutic strategies are needed.

AREAS COVERED IN THIS REVIEW

This review focuses on emerging drugs in the treatment of CD and reviews data on their efficacy and safety. An extensive review of the available literature was undertaken using MEDLINE to identify relevant studies.

WHAT THE READER WILL GAIN

The reader will learn about current therapeutic strategies in patients with CD and gain insights into emerging new drugs.

TAKE HOME MESSAGE

As modification of the clinical course of CD becomes the therapeutic paradigm, potential future treatments have to induce mucosal healing in order to prevent long-term complications. New biologics show promising results.

Overcoming self-tolerance to tumour cells

Over the past decade, immunotherapy has emerged as a promising alternative form of cancer treatment with the potential to eradicate tumour metastasis. However, its curative potential is in general limited by peripheral tolerance mechanisms and the elimination of self-reactive T cells via thymic negative selection. Unlike infectious challenges, tumour cells arise endogenously, and therefore the majority of tumour antigens are recognized as self. Under appropriate conditions, however, tumour reacting T cells can be activated through a mechanism of molecular mimicry, which involves the recognition of cross reactive foreign antigens mimicking tumour antigens. Moreover, dendritic cells can be reprogrammed by RNA interference to present self-antigens and activate anti-tumour T cells. This review highlights some of the strategies used to break self-tolerance against solid and blood tumour cells. Also, the possibility of reprogramming DC and/or lymphocyte functions using small interfering RNAi (siRNA) is discussed.

Impact of female cigarette smoking on circulating B cells in vivo: the suppressed ICOSLG, TCF3, and VCAM1 gene functional network may inhibit normal cell function

As pivotal immune guardians, B cells were found to be directly associated with the onset and development of many smoking-induced diseases. However, the in vivo molecular response of B cells underlying the female cigarette smoking remains unknown. Using the genome-wide Affymetrix HG-133A GeneChip microarray, we firstly compared the gene expression profiles of peripheral circulating B cells between 39 smoking and 40 non-smoking healthy US white women. A total of 125 differential expressed genes were identified in our study, and 75.2% of them were down-regulated in smokers. We further obtained genotypes of 702 single nucleotide polymorphisms in those promising genes and assessed their associations with smoking status. Using a novel multicriteria evaluation model integrating information from microarray and the association studies, several genes were further revealed to play important roles in the response of smoking, including ICOSLG (CD275, inducible T-cell co-stimulator ligand), TCF3 (E2A immunoglobulin enhancer binding factors E12/E47), VCAM1 (CD106, vascular cell adhesion molecule 1), CCR1 (CD191, chemokine C-C motif receptor 1) and IL13 (interleukin 13). The differential expression of ICOSLG (p = 0.0130) and TCF3 (p = 0.0125) genes between the two groups were confirmed by real-time reverse transcription PCR experiment. Our findings support the functional importance of the identified genes in response to the smoking stimulus. This is the first in vivo genome-wide expression study on B cells at today's context of high prevalence rate of smoking for women. Our results highlight the potential usage of integrated analyses for unveiling the novel pathogenesis mechanism and emphasized the significance of B cells in the etiology of smoking-induced disease.

Tobacco, a highly efficient green bioreactor for production of therapeutic proteins

Molecular farming of pharmaceuticals in plants has the potential to provide almost unlimited amounts of recombinant proteins for use in disease diagnosis, prevention or treatment. Tobacco has been and will continue to be a major crop for molecular farming and offers several practical advantages over other crops. It produces significant leaf biomass, has high soluble protein content and is a non-food crop, minimizing the risk of food-chain contamination. This, combined with its flexibility and highly-efficient genetic transformation/regeneration, has made tobacco particularly well suited for plant-based production of biopharmaceutical products. The goal of this review is to provide an update on the use of tobacco for molecular farming of biopharmaceuticals as well the technologies developed to enhance protein production/purification/efficacy. We show that tobacco is a robust biological reactor with a multitude of applications and may hold the key to success in plant molecular farming.

Immune reconstitution inflammatory syndrome and solid organ transplant recipients: are children protected?

The IRIS was initially described in HIV-positive patients as a sudden clinical deterioration after the introduction of highly active retroviral therapy. It is believed that IRIS is caused by a restored and exaggerated inflammatory immune response to different infectious or non-infectious triggers. This abnormal response is the consequence of an imbalance between pro-inflammatory and anti-inflammatory states. Recently, IRIS has also been reported in adult SOT recipients, causing local and systemic manifestations, and compromising long-term graft function and patient survival. However, IRIS has to date not been reported in pediatric SOT recipients. Here we review what is known and speculated about the pathogenesis of IRIS and propose that children may be relatively protected from IRIS.

Advances in RNA sensing by the immune system: separation of siRNA unwanted effects from RNA interference

Small interfering RNAs (siRNAs) are routinely used as a genetic tool and hold promise for a range of therapeutic applications. However, one of the hurdles of making these agents a real therapeutic modality includes the activation of innate immunity and off-target effects. Therefore, the use of siRNAs in functional genomics and therapies depends on the development of new strategies to overcome these unwanted effects. It appears that the major innate immune response to chemically synthesized siRNAs is mediated by TLR7 and/or TLR8 in immune cells. Importantly, it has also been shown that the replacement of uridines with their 2'-modified counterparts can prevent immune activation. Similarly, 2'-modifications, particularly at the seed sequence reduced the number of unwanted off-target genes without interfering with siRNA silencing potency of the anticipated target gene. This chapter describes how to separate gene silencing from immunostimulation. Also, it discusses the impact of these findings on the design of effective cancer vaccines.

Pathway focused protein profiling indicates differential function for IL-1B, -18 and VEGF during initiation and resolution of lung inflammation evoked by carbon nanoparticle exposure in mice

Background

Carbonaceous nanoparticles possess an emerging source of human exposure due to the massive release of combustion products and the ongoing revolution in nanotechnology. Pulmonary inflammation caused by deposited nanoparticles is central for their adverse health effects. Epidemiological studies suggest that individuals with favourable lung physiology are at lower risk for particulate matter associated respiratory diseases probably due to efficient control of inflammation and repair process. Therefore we selected a mouse strain C3H/HeJ (C3) with robust lung physiology and exposed it to moderately toxic carbon nanoparticles (CNP) to study the elicited pulmonary inflammation and its resolution.

Methods

5 μg, 20 μg and 50 μg CNP were intratracheally (i.t.) instilled in C3 mice to identify the optimal dose for subsequent time course studies. Pulmonary inflammation was assessed using histology, bronchoalveolar lavage (BAL) analysis and by a panel of 62 protein markers.

Results

1 day after instillation of CNP, C3 mice exhibited a typical dose response, with the lowest dose (5 μg) representing the 'no effect level' as reflected by polymorphonuclear leucocyte (PMN), and BAL/lung concentrations of pro-inflammatory proteins. Histological analysis and BAL-protein concentration did not reveal any evidence of tissue injury in 20 μg CNP instilled animals. Accordingly time course assessment of the inflammatory response was performed after 3 and 7 days with this dose (20 μg). Compared to day 1, BAL PMN counts were significantly decreased at day 3 and completely returned to normal by day 7. We have identified protein markers related to the acute response and also to the time dependent response in lung and BAL. After complete resolution of PMN influx on day 7, we detected elevated concentrations of 20 markers that included IL1B, IL18, FGF2, EDN1, and VEGF in lung and/or BAL. Biological pathway analysis revealed these factors to be involved in a closely regulated molecular cascade with IL1B/IL18 as upstream and FGF2/EDN1/VEGF as downstream molecules.

Conclusion

Considering the role of VEGF, FGF2 and EDN1 in lung development and morphogenesis together with the lack of any evident tissue damage we suggest a protective/homeostatic machinery to be associated in lungs of stable organisms to counter the CNP challenge as a precautionary measure.

Inflammation in aging part 1: physiology and immunological mechanisms

During the aging process, remodeling of several body systems occurs, and these changes can have a startling effect upon the immune system. The reduction in sex steroids and growth hormones and declines in vitamin D concentration that accompany the aging process are associated with increases in the baseline levels of inflammatory proteins. At the same time, inflammation arising from atherosclerosis and other chronic diseases further contributes to the inflammatory milieu and effects a state of chronic inflammation. This chronic inflammation, or ''inflammaging'' as it has been termed, seems to be associated with a host of adverse effects contributing to many of the health problems that increase morbidity and decrease both quality of life and the ability to maintain independence in old age. For nurses to be truly informed when caring for older people and to ensure that they have a detailed understanding of the complexities of older people's health needs, they must have a knowledge of the physiological and immunological changes with age. This is the first of a two-part article on inflammatory processes in aging. These age-related changes are presented here, including an examination of the impact of genetic and lifestyle factors. The effect of these changes on the health of the individual and implications for practice are described in Part 2.

pSTAT1, pSTAT3, and T-bet as markers of disease activity in chronic inflammatory demyelinating polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is considered an auto-immune disorder. We evaluated expression of pSTAT1, T-bet, and pSTAT3 in circulating T-cells, B-cells, and monocytes and spontaneous production of interleukin-17 (IL17), interferon-gamma (IFN gamma), and interleukin-10 (IL10) by peripheral blood mononuclear cells (PBMCs) from 14 active CIDP patients compared with 6 patients with long-lasting remission and 20 controls. Active disease patients showed higher pSTAT1, T-bet, and pSTAT3 in CD4(+) T-cells than controls (p < 0.001, p = 0.0002, p = 0.0097, respectively) and remission patients (p < 0.001, p = 0.0036, p = 0.0008, respectively). pSTAT1, T-bet, and pSTAT3 were also higher in monocytes from active CIDP patients than controls (p = 0.0011, p = 0.0041, p = 0.0413, respectively) and remission patients (p = 0.0073, p = 0.0274, p = 0.0251, respectively). Moreover in CD8(+) T-cells, pSTAT3 expression was higher in active CIDP patients than in remission patients (p = 0.0345) and in controls (p = 0.0023). IL17 and IFN gamma production were significantly higher in active CIDP patients than in controls (p < 0.0395, p = 0.0010, respectively); IFN gamma levels were higher also in remission CIDP patients (p = 0.0073). IL10 levels were higher in active phase patients than in controls (p = 0.0334). Our data suggest that pSTAT1, T-bet, and pSTAT3 can be considered putative markers of disease activity and potential targets for specific therapies.

Immune reconstitution inflammatory syndrome in non-HIV immunocompromised patients

PURPOSE OF REVIEW

In the era of highly active antiretroviral therapy, immune reconstitution inflammatory syndrome has become well recognized in the HIV-infected population. However, little is known about its occurrence in non-HIV immunocompromised hosts. The present review aims to propose the pathogenesis of immune reconstitution inflammatory syndrome, summarize its occurrence in immunocompromised patients without HIV infection, and suggest potential treatment options.

RECENT FINDINGS

Immune reconstitution inflammatory syndrome is exuberant and dysregulated inflammatory responses to invading microorganisms. It manifests when an abrupt shift of host immunity from an anti-inflammatory and immunosuppressive status towards a pathogenic proinflammatory state occurs as a result of rapid decreases or removal of factors promoting immunosuppression or inhibiting inflammation. In addition to HIV-infected patients, immune reconstitution inflammatory syndrome has also been observed in solid organ transplant recipients, women during the postpartum period, neutropenic patients, and tumor necrosis factor antagonist recipients. Corticosteroids are the most commonly employed treatment, whereas other potential agents based on its pathogenesis deserve further investigation.

SUMMARY

Non-HIV immunocompromised hosts develop immune reconstitution inflammatory syndrome when the sudden change in the dominant T helper responses to inflammation is not well balanced by anti-inflammatory responses. Judicious manipulation of host immunity and timely recognition of immune reconstitution inflammatory syndrome as we deal with the infections in these populations is critical to limit or avoid the harm by immune reconstitution inflammatory syndrome.

Natural antibodies and cancer

The innate or natural immunity is the basis and key for all immune processes. Specific receptors on macrophages, dendrites, NK cells and natural antibodies producing B cells act as a first line defense and remove all 'foreign' and potentially harmful substances, that is, bacteria, viruses, cellular waste, modified molecules and, most importantly, cancer cells. Recognition and removal of transformed cells is a lifelong task of immune surveillance processes. Antibodies are hallmark components of this anti-cancer activity. To investigate their nature, specificity, and function, we used the human hybridoma technology for isolating antibodies from cancer patients. These were then tested with a panel of assays against cancer cell lines in vitro and in vivo. Interestingly, all the tumor-specific antibodies we found were germ-line coded and belonged nearly exclusively to the IgM class. Furthermore, they all bound to new carbohydrates on post-translationally modified cell surface receptors on malignant cells. So far no affinity maturated immunoglobulins detecting tumor-specific peptides were found. However, only the presentation of peptide motifs can create an immunological memory. In general malignant cells are detected at very early precursor stages and manifest tumors can be considered as exceptional events. In addition, malignant cells are neither infectious nor hide intracellularly like viruses and some bacteria. Therefore, it makes sense that anti-tumor immunity seems to be solely a part of the natural immunity and a memory is not needed and therefore not induced. This indicates that the tumor immunity seems to be restricted to innate immune mechanisms and the instruments used by nature, like natural antibodies, are obviously excellent therapeutics.

Saccharomyces boulardii inhibits lipopolysaccharide-induced activation of human dendritic cells and T cell proliferation

Saccharomyces boulardii (Sb) is a probiotic yeast preparation that has demonstrated efficacy in inflammatory and infectious disorders of the gastrointestinal tract in controlled clinical trials. Although patients clearly benefit from treatment with Sb, little is known on how Sb unfolds its anti-inflammatory properties in humans. Dendritic cells (DC) balance tolerance and immunity and are involved critically in the control of T cell activation. Thus, they are believed to have a pivotal role in the initiation and perpetuation of chronic inflammatory disorders, not only in the gut. We therefore decided to investigate if Sb modulates DC function. Culture of primary (native, non-monocyte-derived) human myeloid CD1c+CD11c+CD123(-) DC (mDC) in the presence of Sb culture supernatant (active component molecular weight < 3 kDa, as evaluated by membrane partition chromatography) reduced significantly expression of the co-stimulatory molecules CD40 and CD80 (P < 0.01) and the DC mobilization marker CC-chemokine receptor CCR7 (CD197) (P < 0.001) induced by the prototypical microbial antigen lipopolysaccharide (LPS). Moreover, secretion of key proinflammatory cytokines such as tumour necrosis factor-alpha and interleukin (IL)-6 were notably reduced, while the secretion of anti-inflammatory IL-10 increased. Finally, Sb supernatant inhibited the proliferation of naive T cells in a mixed lymphocyte reaction with mDC. In summary, our data suggest that Sb may exhibit part of its anti-inflammatory potential through modulation of DC phenotype, function and migration by inhibition of their immune response to bacterial microbial surrogate antigens such as LPS.

Deciphering the code of innate immunity recognition of siRNAs

Small interfering RNAs (siRNAs) have been widely used for knocking down gene expression in a variety of organisms. Although experiments in cancer cell lines indicate that siRNAs are usually not detected by innate immunity, lipid-mediated delivery of siRNAs into blood cells is often accompanied by the activation of immunity. Recent studies indicated that certain siRNA sequences engage Toll-like receptor TLR7/8 signalling resulting in the activation of a large number of host defense genes including interferons (IFNs), proinflammatory cytokines, Mx proteins, chemokines, chemokine receptors, costimulatory molecules, RNA helicases, galectins, and ubiqitin ligases. In addition to immune activation, most siRNA sequences, if not all, can silence multiple genes in addition to the intended target gene, a phenomenon known as "off-target effects." Hence, one of the major challenges for therapeutic applications of siRNAs is to decipher the mechanisms involved in siRNA recognition by the immune system and to identify strategies that can evade immune activation. In this respect, the replacement of only uridines with their 2'-modified counterparts such as 2'-O-methyl uridines abrogates immune recognition of siRNAs. Interestingly, 2'-O-methyl-modified RNAs not only evade TLR7/8-sensing pathways, but also reduce siRNA off-target effects and antagonize with a variety of immunostimulatory RNAs to activate TLR7/8 signalling. RNA oligonucleotides and duplex siRNAs with 2'-deoxy uridines or thymidines exhibited no significant immunostimulatory effects and binding potency to TLRs. Therefore, I recommend the use of these modifications in order to evade immune sensing of siRNA and off-target effects. This chapter addresses the current state of knowledge regarding the molecular and cellular mechanisms of RNA recognition by the immune system and proposes a range of strategies allowing the design of siRNAs with minimal or maximal immunostimulatory potency for therapeutic applications.

[HLA-B*5701 and hypersensitivity reactions to abacavir. Study methods and clinical relevance]

Hypersensitivity reactions to abacavir occur in 5-8% of patients starting treatment with this drug and limits future treatment. Some host genetic factors, especially the HLA-B*5701 allele, have been identified as risk factors for hypersensitivity reaction in Caucasians. Consequently, the possibility of routine implementation of a genetic test to rule out the presence of this allele has been proposed to achieve a personalized therapeutic profile. The present article discusses all the information related to hypersensitivity to abacavir and its genetic and immunological markers, as well as the distinct techniques for HLA-B*5701 allele detection. The various studies performed to date in distinct population are also discussed.

Interleukin-6 blood levels in sensitive and multiresistant tuberculosis

BACKGROUND

Interleukin-6 (IL-6) is a proinflammatory cytokine implicated in the immunopathogenesis of tuberculosis (TB). Multidrug resistance in tuberculosis is recognized worldwide as an important public health issue. The mechanism underlying TB pathogenesis in general and drug resistance in particular is not well understood, but it may be that IL-6 is one factor that enhances pathology in drug-resistant TB. The purpose of this study was to identify patterns of IL-6 production in active pulmonary TB with different sensitivity to standard drug therapy.

PATIENTS AND METHODS

IL-6 blood levels were studied in 38 patients with active pulmonary TB: 23 patients were very sensitive to specific chemotherapy (STB), and 15 were multiresistant (MDRTB). An ELISA assay (Biossource) was used to quantify IL-6 in the sera of 38 TB patients and 63 healthy blood donors.

RESULTS

The STB group was composed of 16 males (73.9%) and 7 females, MDRTB by 9 males (60%) and 6 females, and control group by 51 males (81%) and 12 females. The results showed a significant increase in IL-6 concentration in TB (median = 4.3 pg/ml, range 0.5-24) compared to that of healthy individuals (median = 0.5 pg/ml, range 0-2.8, p < 0.001). Additionally, IL-6 concentrations were increased in both STB (median = 4.1 pg/ml, range 0.5-24) and MDRTB (median = 5.1 pg/ml, range 0.5-12) groups in relation to controls (p < 0.001). In contrast, significant differences were not observed between STB and MDRTB groups (p > 0.05).

CONCLUSION

IL-6 levels were increased in pulmonary tuberculosis, independent of drug resistance.

Iron overload and unique susceptibility of liver transplant recipients to disseminated disease due to opportunistic pathogens

The propensity of liver transplant recipients to develop more fulminant disease presentation and a higher risk of disseminated disease due to a number of opportunistic infections, including invasive aspergillosis, cryptococcosis, zygomycosis, may be related to iron overload. Abnormalities in iron homeostasis may also be a contributor to severe manifestations due to other pathogens such as cytomegalovirus and Staphylococcus aureus in liver transplant recipients. Iron is essential not only for microbial pathogenesis, but directly impairs pivotal pathogen specific host defenses. Studies to assess iron homeostasis and the mechanisms by which iron overload contributes to the pathogenesis of opportunistic infections in liver transplant recipients are warranted.

Novel immune regulatory pathways and their role in immune reconstitution syndrome in organ transplant recipients with invasive mycoses

Immune regulatory pathways involving the newly discovered T regulatory (Treg) and Th17 cells are amongst the principal targets of immunosuppressive agents employed in transplant recipients and key mediators of host inflammatory responses in fungal infections. These novel signaling pathways, in concert with or independent of Th1/Th2 responses, have potentially important implications for yielding valuable insights into the pathogenesis of immune reconstitution syndrome (IRS) in transplant recipients, for aiding the diagnosis of this entity, and for achieving a balance of immune responses that enhance host immunity while curbing unfettered inflammation in IRS.

Exaggerated expression of inflammatory mediators in vasoactive intestinal polypeptide knockout (VIP-/-) mice with cyclophosphamide (CYP)-induced cystitis

Vasoactive intestinal polypeptide (VIP) is an immunomodulatory neuropeptide distributed in micturition pathways. VIP(-/-) mice exhibit altered bladder function and neurochemical properties in micturition pathways after cyclophosphamide (CYP)-induced cystitis. Given VIP's role as an anti-inflammatory mediator, we hypothesized that VIP(-/-) mice would exhibit enhanced inflammatory mediator expression after cystitis. A mouse inflammatory cytokine and receptor RT2 profiler array was used to determine regulated transcripts in the urinary bladder of wild type (WT) and VIP(-/-) mice with or without CYP-induced cystitis (150 mg/kg; i.p.; 48 h). Four binary comparisons were made: WT control versus CYP treatment (48 h), VIP(-/-) control versus CYP treatment (48 h), WT control versus VIP(-/-) control, and WT with CYP treatment (48 h) versus VIP(-/-) with CYP treatment (48 h). The genes presented represent (1) greater than 1.5-fold change in either direction and (2) the p value is less than 0.05 for the comparison being made. Several regulated genes were validated using enzyme-linked immunoassays including IL-1beta and CXCL1. CYP treatment significantly (p < or = 0.001) increased expression of CXCL1 and IL-1beta in the urinary bladder of WT and VIP(-/-) mice, but expression in VIP(-/-) mice with CYP treatment was significantly (p < or = 0.001) greater (4.2- to 13-fold increase) than that observed in WT urinary bladder (3.6- to 5-fold increase). The data suggest that in VIP(-/-) mice with bladder inflammation, inflammatory mediators are increased above that observed in WT with CYP. This shift in balance may contribute to increased bladder dysfunction in VIP(-/-) mice with bladder inflammation and altered neurochemical expression in micturition pathways.

Peripheral blood dendritic cell subsets from patients with monoclonal gammopathies show an abnormal distribution and are functionally impaired

Objectives. The information currently available about dendritic cells (DCs) in patients with different types of monoclonal gammopathy (MG) is limited and frequently controversial. In the present study, we analyzed the ex vivo distribution as well as the phenotypic and functional characteristics of peripheral blood (PB) DCs from different types of MG. Methods. For this purpose, 61 untreated patients in total with MG were analyzed-MG of undetermined significance (MGUS), 29 cases; multiple myeloma (MM), 28 cases; and plasma cell leukemia (PCL), 4 cases-in comparison with a group of 10 healthy controls. Results. Our results show an absolute overall higher number of all subsets of PB DCs in PCL, together with lower numbers of myeloid DCs in MM patients. From a phenotypic point of view, PB DC subsets from all types of MG expressed significantly higher levels of HLA molecules and altered patterns of expression of the CD2, CD11c, CD16, CD22, CD62L, and CD86 molecules, in association with altered patterns of secretion of inflammatory cytokines. Conclusion. In summary, we show the existence of significant abnormalities in the distribution, phenotype, and pattern of secretion of inflammatory cytokines by different subsets of PB DCs from patients with MGs, which could reflect a potentially altered homing of DCs, together with a greater in vivo activation and lower responsiveness of PB DCs, which are already detectable in MGUS patients.

Fucoidin prevents Clostridium difficile toxin-A-induced ileal enteritis in mice

Recent reports suggest increased incidence and severity of Clostridium difficile-associated diseases. These facts have raised the need for additional clarification of pathogenesis and for a search for new therapeutic strategies. This study evaluated the effects of the polysaccharide fucoidin, an L-selectin blocker, on toxin-A-induced mouse enteritis. Fucoidin (25 mg/kg) or saline (0.1 ml) were injected systemically (ocular plexus) 5 min prior to local challenge with toxin A (5 microg/ileal loop) or phosphate-buffered saline (PBS). Intestinal fluid volume/length and ileal loop weight/length ratios were calculated 3 h later. Ileal tissues were collected for histopathology and measurement of myeloperoxidase and adenosine deaminase activity. Fucoidin significantly (P < 0.05) prevented the toxin-A-induced increase in weight/length and volume/length ratios and reduced mucosal disruption, as shown in histopathology. Fucoidin also significantly (P < 0.05) reduced toxin-A-induced myeloperoxidase and adenosine deaminase activities. In conclusion, fucoidin reduces tissue injury and inflammation in toxin-A-induced mouse enteritis.

Health effects of quercetin: from antioxidant to nutraceutical

Quercetin, a member of the flavonoids family, is one of the most prominent dietary antioxidants. It is ubiquitously present in foods including vegetables, fruit, tea and wine as well as countless food supplements and is claimed to exert beneficial health effects. This includes protection against various diseases such as osteoporosis, certain forms of cancer, pulmonary and cardiovascular diseases but also against aging. Especially the ability of quercetin to scavenge highly reactive species such as peroxynitrite and the hydroxyl radical is suggested to be involved in these possible beneficial health effects. Consequently, numerous studies have been performed to gather scientific evidence for these beneficial health claims as well as data regarding the exact mechanism of action and possible toxicological aspects of this flavonoid. The purpose of this review is to evaluate these studies in order to elucidate the possible health-beneficial effects of the antioxidant quercetin. Firstly, the definitions as well as the most important aspects regarding free radicals, antioxidants and oxidative stress will be discussed as background information. Subsequently, the mechanism by which quercetin may operate as an antioxidant (tested in vitro) as well as the potential use of this antioxidant as a nutraceutical (tested both ex vivo and in vivo) will be discussed.

Selected vitamins and trace elements support immune function by strengthening epithelial barriers and cellular and humoral immune responses

Adequate intakes of micronutrients are required for the immune system to function efficiently. Micronutrient deficiency suppresses immunity by affecting innate, T cell mediated and adaptive antibody responses, leading to dysregulation of the balanced host response. This situation increases susceptibility to infections, with increased morbidity and mortality. In turn, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Insufficient intake of micronutrients occurs in people with eating disorders, in smokers (active and passive), in individuals with chronic alcohol abuse, in certain diseases, during pregnancy and lactation, and in the elderly. This paper summarises the roles of selected vitamins and trace elements in immune function. Micronutrients contribute to the body's natural defences on three levels by supporting physical barriers (skin/mucosa), cellular immunity and antibody production. Vitamins A, C, E and the trace element zinc assist in enhancing the skin barrier function. The vitamins A, B6, B12, C, D, E and folic acid and the trace elements iron, zinc, copper and selenium work in synergy to support the protective activities of the immune cells. Finally, all these micronutrients, with the exception of vitamin C and iron, are essential for antibody production. Overall, inadequate intake and status of these vitamins and trace elements may lead to suppressed immunity, which predisposes to infections and aggravates malnutrition. Therefore, supplementation with these selected micronutrients can support the body's natural defence system by enhancing all three levels of immunity.

Pain and stress in a systems perspective: reciprocal neural, endocrine, and immune interactions

This paper advances a psychophysiological systems view of pain in which physical injury, or wounding, generates a complex stress response that extends beyond the nervous system and contributes to the experience of pain. Through a common chemical language comprising neurotransmitters, peptides, endocannabinoids, cytokines, and hormones, an ensemble of interdependent nervous, endocrine, and immune processes operates in concert to cope with the injury. These processes act as a single agent and comprise a supersystem. Acute pain in its multiple dimensions, and the related symptoms that commonly occur with it, are products of the supersystem. Chronic pain can develop as a result of unusual stress. Social stressors can compound the stress resulting from a wound or act alone to dysregulate the supersystem. When the supersystem suffers dysregulation, health, function, and sense of well-being suffer. Some chronic pain conditions are the product of supersystem dysregulation. Individuals vary and are vulnerable to dysregulation and dysfunction in particular organ systems due to the unique interactions of genetic, epigenetic and environmental factors, as well as the past experiences that characterize each person.

PERSPECTIVE

Acute tissue injury activates an ensemble of interdependent nervous, endocrine, and immune processes that operate in concert and comprise a supersystem. Some chronic pain conditions result from supersystem dysregulation. Individuals vary and are vulnerable to dysregulation due to the unique interactions of genetic, epigenetic, and environmental factors and past experiences that characterize each person. This perspective can potentially assist clinicians in assessing and managing chronic pain patients.

Cytokine Profiling in Abacavir Hypersensitivity Patients

Background

Abacavir hypersensitivity in genetically susceptible individuals implicates an abacavir-specific T-cell response to either the parent drug or a metabolite generated in vivo. We have analysed the cytokine profile in antigen-presenting cells and the T-lymphocytes that are involved in the pathological immune response to abacavir.

Methods

In this study, we compared abacavir-specific cytokine responses in cultured peripheral blood mononuclear cells (PBMCs) from HIV-infected abacavir hypersensitive, tolerant and naive individuals. Cells were cultured in the presence or absence of abacavir. Cytokine expression was determined by microarray analysis, enzyme-linked immunosorbent assays and flow cytometry.

Results

We demonstrated using in vitro models of immune activation that the production of interferon-γwas specifically induced by abacavir treatment in PBMCs obtained from hypersensitive patients carrying the HLA-B*5701 allele (median 123.86 compared with -30.83 for tolerant controls, P=0.001).

Conclusion

These results provide further insight into the immunological and metabolic basis of abacavir hypersensitivity syndrome. In vitro assays could assist in the identification of susceptible loci by providing a surrogate marker for the hypersensitivity reaction. Such a marker could be studied in unexposed individuals to shed further light on the immunopathogenesis of the abacavir hypersensitivity syndrome.

Multiobjective immune algorithm with nondominated neighbor-based selection

Abstract Nondominated Neighbor Immune Algorithm (NNIA) is proposed for multiobjective optimization by using a novel nondominated neighbor-based selection technique, an immune inspired operator, two heuristic search operators, and elitism. The unique selection technique of NNIA only selects minority isolated nondominated individuals in the population. The selected individuals are then cloned proportionally to their crowding-distance values before heuristic search. By using the nondominated neighbor-based selection and proportional cloning, NNIA pays more attention to the less-crowded regions of the current trade-off front. We compare NNIA with NSGA-II, SPEA2, PESA-II, and MISA in solving five DTLZ problems, five ZDT problems, and three low-dimensional problems. The statistical analysis based on three performance metrics including the coverage of two sets, the convergence metric, and the spacing, show that the unique selection method is effective, and NNIA is an effective algorithm for solving multiobjective optimization problems. The empirical study on NNIA's scalability with respect to the number of objectives shows that the new algorithm scales well along the number of objectives.

Gene expression changes in children with autism

The objective of this study was to identify gene expression differences in blood differences in children with autism (AU) and autism spectrum disorder (ASD) compared to general population controls. Transcriptional profiles were compared with age- and gender-matched, typically developing children from the general population (GP). The AU group was subdivided based on a history of developmental regression (A-R) or a history of early onset (A-E without regression). Total RNA from blood was processed on human Affymetrix microarrays. Thirty-five children with AU (17 with early onset autism and 18 with autism with regression) and 14 ASD children (who did not meet criteria for AU) were compared to 12 GP children. Unpaired t tests (corrected for multiple comparisons with a false discovery rate of 0.05) detected a number of genes that were regulated more than 1.5-fold for AU versus GP (n=55 genes), for A-E versus GP (n=140 genes), for A-R versus GP (n=20 genes), and for A-R versus A-E (n=494 genes). No genes were significantly regulated for ASD versus GP. There were 11 genes shared between the comparisons of all autism subgroups to GP (AU, A-E, and A-R versus GP) and these genes were all expressed in natural killer cells and many belonged to the KEGG natural killer cytotoxicity pathway (p=0.02). A subset of these genes (n=7) was tested with qRT-PCR and all genes were found to be differentially expressed (p<0.05). We conclude that the gene expression data support emerging evidence for abnormalities in peripheral blood leukocytes in autism that could represent a genetic and/or environmental predisposition to the disorder.

Natural antibodies and cancer

Immunity is not only responsible for recognition and elimination of infectious particles, but also for removal of cellular waste, modified self structures and transformed cells. Innate or natural immunity acts as a first line defense and is also the link to acquired immunity and memory. A striking phenomenon of immunity against malignant cells is that neither in animals nor in humans affinity-maturated tumor-specific IgG antibodies have been detected so far. All tumor-specific isolated antibodies were germ-line coded natural IgM antibodies. It's also a fact that these IgM's preferentially bind to carbohydrate epitopes on post-transcriptionally modified surface receptors and that they all induce a cancer-specific apoptosis, by triggering the intrinsic apoptotic pathway. From an evolutionary point of view, this makes sense because cancer cells are not infectious, so there is no need for memory. Natural IgMs bind to conservative structures because they are coded by a limited set of genes and they use apoptosis, the "clean" way of killing, to avoid inflammatory processes.

Contribution of selected vitamins and trace elements to immune function

Adequate intakes of vitamins and trace elements are required for the immune system to function efficiently. Micronutrient deficiency suppresses immune functions by affecting the innate T-cell-mediated immune response and adaptive antibody response, and leads to dysregulation of the balanced host response. This increases the susceptibility to infections, with increased morbidity and mortality. In turn, infections aggravate micronutrient deficiencies by reducing nutrient intake, increasing losses, and interfering with utilization by altering metabolic pathways. Insufficient intake of micronutrients occurs in people with eating disorders, in smokers (both active and passive), in individuals with chronic alcohol abuse, in patients with certain diseases, during pregnancy and lactation, and in the elderly. With aging a variety of changes are observed in the immune system, which translate into less effective innate and adaptive immune responses and increased susceptibility to infections. Antioxidant vitamins and trace elements (vitamins C, E, selenium, copper, and zinc) counteract potential damage caused by reactive oxygen species to cellular tissues and modulate immune cell function through regulation of redox-sensitive transcription factors and affect production of cytokines and prostaglandins. Adequate intake of vitamins B(6), folate, B(12), C, E, and of selenium, zinc, copper, and iron supports a Th1 cytokine-mediated immune response with sufficient production of proinflammatory cytokines, which maintains an effective immune response and avoids a shift to an anti-inflammatory Th2 cell-mediated immune response and an increased risk of extracellular infections. Supplementation with these micronutrients reverses the Th2 cell-mediated immune response to a proinflammatory Th1 cytokine-regulated response with enhanced innate immunity. Vitamins A and D play important roles in both cell-mediated and humoral antibody response and support a Th2-mediated anti-inflammatory cytokine profile. Vitamin A deficiency impairs both innate immunity (mucosal epithelial regeneration) and adaptive immune response to infection resulting in an impaired ability to counteract extracellular pathogens. Vitamin D deficiency is correlated with a higher susceptibility to infections due to impaired localized innate immunity and defects in antigen-specific cellular immune response. Overall, inadequate intake and status of these vitamins and minerals may lead to suppressed immunity, which predisposes to infections and aggravates malnutrition.