Natural antibodies, intravenous immunoglobulin and their role in autoimmunity, cancer and inflammation

Protective and immunomodulatory effects of mesenchymal stem cells on multiorgan injury in male rats with heatstroke

Heatstroke (HS) causes multiple organ dysfunction syndrome (MODS) with a mortality rate of 60% after hospitalization. Currently, there is no effective and targeted approach for the treatment of HS. Despite growing evidence that mesenchymal stem cells (MSCs) may reduce multiorgan damage and improve survival through immunomodulatory effects in several diseases, no one has tested whether MSCs have immunomodulatory effects in heatstroke. The present study focused on pathological changes and levels of the cytokines and immunoglobulins to investigate the mechanisms underlying the protective effect and the anti-inflammatory effects of MSCs. We found that MSCs treatment significantly reduced the 28-day mortality rate (P < 0.05), the levels of hepatic and renal function markers on day 1 (P < 0.01) and the pathological lesion scores of multiple organs in HS rats. The levels of IgG1, IgM, and IgA of the HS + MSC group was significantly higher than that in HS group on days 3 and 28(P < 0.05). In conclusion, MSCs contribute to protecting against multiorgan injury, reducing pro-inflammatory cytokines, stabilizing immunoglobulins, and reducing the mortality rate of HS rats.

Comparative effectiveness of two intravenous immunoglobulin products in children with Kawasaki disease, a nationwide cohort study

Kawasaki Disease (KD) is the most common acquired pediatric heart disease in the developed world. Rapid infusion of high-dose intravenous immunoglobulin is the standard therapy. Different manufacturing processes of IVIG may influence their efficacy. This study aims to conduct a head to head comparison of two IVIGs, TBSF and Privigen, from a nationwide perspective. The main data source was the National Health Insurance Research Database (NHIRD) of Taiwan. A total of 3368 KD cases involving children under 2 years of age were enrolled from January 2015 to November 2020. The primary endpoint was IVIG resistance, which we defined as the total amount exceeding 26 g in one admission. The secondary endpoints encompassed two distinct criteria: coronary involvement, which was defined as the prolonged use of aspirin or anti-coagulation agents between 180 and 360 days after the index date, and recurrence, which was defined as readmission for IVIG therapy occurring more than 30 days after previous KD index day and continuing until the end of the follow-up period. Privigen demonstrated a lower IVIG resistance rate at 9.4% in comparison to TBSF, which exhibited a rate of 9.7% (odds ratio 0.72, 95% CI 0.52-0.99). Privigen had a lower odds of coronary involvement (odds ratio 0.38, 95% CI 0.18-0.82). There is no difference in recurrence rate (odds ratio 0.60, 95% CI 0.22-1.68). Privigen might have a lower rate of IVIG resistance and reduced coronary artery involvement. The discrepancy may be due to the concentration, the stabilizers, or the source of plasma. Further investigation is needed to compare the effectiveness of different IVIGs in the large randomized controlled clinical trial.

Antibody Cross-Reactivity in Auto-Immune Diseases

Autoimmunity is defined by the presence of antibodies and/or T cells directed against self-components. Although of unknown etiology, autoimmunity commonly is associated with environmental factors such as infections, which have been reported to increase the risk of developing autoimmune diseases. Occasionally, similarities between infectious non-self and self-tissue antigens may contribute to immunological cross-reactivity in autoimmune diseases. These reactions may be interpreted as molecular mimicry, which describes cross-reactivity between foreign pathogens and self-antigens that have been reported to cause tissue damage and to contribute to the development of autoimmunity. By focusing on the nature of antibodies, cross-reactivity in general, and antibody-antigen interactions, this review aims to characterize the nature of potential cross-reactive immune reactions between infectious non-self and self-tissue antigens which may be associated with autoimmunity but may not actually be the cause of disease onset.

Natural and Pathological Autoantibodies Show Age-Related Changes in a Spontaneous Autoimmune Mouse (NZB) Model

The natural autoantibody (natAAb) network is thought to play a role in immune regulation. These IgM antibodies react with evolutionary conserved antigens; however, they do not lead to pathological tissue destruction as opposed to pathological autoantibodies (pathAAb). The exact relation between the natAAbs and pathAAbs is still not completely understood; therefore, in the present study, we set out to measure nat- and pathAAb levels against three conserved antigens in a spontaneous autoimmune disease model: the NZB mouse strain which develops autoimmune hemolytic anemia (AIHA) from six months of age. There was an age dependent increase in the natAAb levels in the serum against Hsp60, Hsp70, and the mitochondrial citrate synthase until 6-9 months of age, followed by a gradual decrease. The pathological autoantibodies appeared after six months of age, which corresponded with the appearance of the autoimmune disease. The changes in nat/pathAAb levels were coupled with decreasing B1- and increasing plasma cell and memory B cell percentages. Based on this, we propose that there is a switch from natAAbs towards pathAAbs in aged NZB mice.

Early detection of lung cancer in a real-world cohort via tumor-associated immune autoantibody and imaging combination

Background

Efficient early detection methods for lung cancer can significantly decrease patient mortality. One promising approach is the use of tumor-associated autoantibodies (TAABs) as a diagnostic tool. In this study, the researchers aimed to evaluate the potential of seven TAABs in detecting lung cancer within a population undergoing routine health examinations. The results of this study could provide valuable insights into the utility of TAABs for lung cancer screening and diagnosis.

Methods

In this study, the serum concentrations of specific antibodies were measured using enzyme-linked immunosorbent assay (ELISA) in a cohort of 15,430 subjects. The efficacy of both a 7-TAAB panel and LDCT for lung cancer detection were evaluated through receiver operating characteristic (ROC) analyses, with sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) being assessed and compared. These results could have significant implications for the development of improved screening methods for lung cancer.

Results

Over the 12-month observation period, 26 individuals were diagnosed with lung cancer. The 7-TAAB panel demonstrated promising sensitivity (61.5%) and a high degree of specificity (88.5%). The panel’s area under the receiver operating characteristic (ROC) curve was 0.8062, which was superior to that of any individual TAAB. In stage I patients, the sensitivity of the panel was 50%. In our cohort, there was no gender or age bias observed. This 7-TAAB panel showed a sensitivity of approximately 60% in detecting lung cancer, regardless of histological subtype or lesion size. Notably, ground-glass nodules had a higher diagnostic rate than solid nodules (83.3% vs. 36.4%, P = 0.021). The ROC analyses further revealed that the combination of LDCT with the 7-TAAB assay exhibited a significantly superior diagnostic efficacy than LDCT alone.

Conclusion

In the context of the study, it was demonstrated that the 7-TAAB panel showed improved detective efficacy of LDCT, thus serving as an effective aid for the detection of lung cancer in real-world scenarios.

Inhibitory effects of circulating natural autoantibodies to CD47-derived peptides on OSCC cells

OBJECTIVES

Natural autoantibodies serve as an important anti-tumorigenic component in the body. This study was thus designed to investigate whether circulating natural IgG autoantibodies against a cluster of differentiation 47 (CD47) could exert inhibitory effects on oral squamous cell carcinoma (OSCC).

SUBJECTS AND METHODS

The expression levels of 13 tumor-targeted genes in three OSCC cell lines were analyzed by qPCR, and CD47 expression in OSCC tissues was also verified with IHC staining. An in-house ELISA was performed to analyze circulating anti-CD47 IgG levels in control subjects, oral benign tumor, and OSCC patients, and to detect anti-CD47 IgG-abundant plasma. Three OSCC cell lines were treated with anti-CD47 IgG-abundant and -deficient plasma, respectively, followed by the analysis of cell proliferation, apoptosis, and invasion/metastasis.

RESULTS

The CD47 gene showed the highest expression among 13 genes detected in three OSCC cell lines; its expression was significantly higher in OSCC tissues than adjacent tissues. Plasma anti-CD47 IgG levels showed the differences between control subjects, oral benign tumor, and OSCC patients. Anti-CD47 IgG-abundant plasma could evidently reduce cell viability via suppressing p-AKT expression and inducing cell apoptosis and inhibit the invasion of all three OSCC cell lines.

CONCLUSIONS

Natural autoantibodies against CD47 may be a potential agent for OSCC immunotherapy.

Physiological status of House Sparrows (Passer domesticus) along an ozone pollution gradient

Mexico City is one of the most polluted cities in the world, and one in which air contamination is considered a public health threat. Numerous studies have related high concentrations of particulate matter and ozone to several respiratory and cardiovascular diseases and a higher human mortality risk. However, almost all of those studies have focused on human health outcomes, and the effects of anthropogenic air pollution on wildlife species is still poorly understood. In this study, we investigated the impacts of air pollution in the Mexico City Metropolitan Area (MCMA) on house sparrows (Passer domesticus). We assessed two physiological responses commonly used as biomarkers: stress response (the corticosterone concentration in feathers), and constitutive innate immune response (the concentration of both natural antibodies and lytic complement proteins), which are non-invasive techniques. We found a negative relationship between the ozone concentration and the natural antibodies response (p = 0.003). However, no relationship was found between the ozone concentration and the stress response or the complement system activity (p > 0.05). These results suggest that ozone concentrations in air pollution within MCMA may constrain the natural antibody response in the immune system of house sparrows. Our study shows, for the first time, the potential impact of ozone pollution on a wild species in the MCMA presenting the Nabs activity and the house sparrow as suitable indicators to assess the effect of air contamination on the songbirds.

DNA methylome and transcriptome identified Key genes and pathways involved in Speckled Eggshell formation in aged laying hens

BACKGROUND

The quality of poultry eggshells is closely related to the profitability of egg production. Eggshell speckles reflect an important quality trait that influences egg appearance and customer preference. However, the mechanism of speckle formation remains poorly understood. In this study, we systematically compared serum immune and antioxidant indices of hens laying speckled and normal eggs. Transcriptome and methylome analyses were used to elucidate the mechanism of eggshell speckle formation.

RESULTS

The results showed that seven differentially expressed genes (DEGs) were identified between the normal and speckle groups. Gene set enrichment analysis (GSEA) revealed that the expressed genes were mainly enriched in the calcium signaling pathway, focal adhesion, and MAPK signaling pathway. Additionally, 282 differentially methylated genes (DMGs) were detected, of which 15 genes were associated with aging, including ARNTL, CAV1, and GCLC. Pathway analysis showed that the DMGs were associated with T cell-mediated immunity, response to oxidative stress, and cellular response to DNA damage stimulus. Integrative analysis of transcriptome and DNA methylation data identified BFSP2 as the only overlapping gene, which was expressed at low levels and hypomethylated in the speckle group.

CONCLUSIONS

Overall, these results indicate that aging- and immune-related genes and pathways play a crucial role in the formation of speckled eggshells, providing useful information for improving eggshell quality.

Transmissible cancer influences immune gene expression in an endangered marsupial, the Tasmanian devil (Sarcophilus harrisii)

Understanding the effects of wildlife diseases on populations requires insight into local environmental conditions, host defence mechanisms, host life‐history trade‐offs, pathogen population dynamics, and their interactions. The survival of Tasmanian devils (Sarcophilus harrisii) is challenged by a novel, fitness limiting pathogen, Tasmanian devil facial tumour disease (DFTD), a clonally transmissible, contagious cancer. In order to understand the devils’ capacity to respond to DFTD, it is crucial to gain information on factors influencing the devils’ immune system. By using RT‐qPCR, we investigated how DFTD infection in association with intrinsic (sex and age) and environmental (season) factors influences the expression of 10 immune genes in Tasmanian devil blood. Our study showed that the expression of immune genes (both innate and adaptive) differed across seasons, a pattern that was altered when infected with DFTD. The expression of immunogbulins IgE and IgM:IgG showed downregulation in colder months in DFTD infected animals. We also observed strong positive association between the expression of an innate immune gene, CD16, and DFTD infection. Our results demonstrate that sampling across seasons, age groups and environmental conditions are beneficial when deciphering the complex ecoevolutionary interactions of not only conventional host‐parasite systems, but also of host and diseases with high mortality rates, such as transmissible cancers.

Nomogram based on clinical characteristics and serological inflammation markers to predict overall survival of oral tongue squamous cell carcinoma patient after surgery

BACKGROUND

Oral tongue squamous cell carcinoma (OTSCC) is a prevalent malignant disease that is characterized by high rates of metastasis and postoperative recurrence. The aim of this study was to establish a nomogram to predict the outcome of OTSCC patients after surgery.

METHODS

We retrospectively analyzed 169 OTSCC patients who underwent treatments in the Cancer Hospital of Shantou University Medical College from 2008 to 2019. The Cox regression analysis was performed to determine the independent prognostic factors associated with patient's overall survival (OS). A nomogram based on these prognostic factors was established and internally validated using a bootstrap resampling method.

RESULTS

Multivariate Cox regression analysis revealed the independent prognostic factors for OS were TNM stage, age, lymphocyte-to-monocyte ratio and immunoglobulin G, all of which were identified to create the nomogram. The Akaike Information Criterion and Bayesian Information Criterion of the nomogram were lower than those of TNM stage (292.222 vs. 305.480; 298.444 vs. 307.036, respectively), indicating a better goodness-of-fit of the nomogram for predicting OS. The bootstrap-corrected of concordance index (C-index) of nomogram was 0.784 (95% CI 0.708-0.860), which was higher than that of TNM stage (0.685, 95% CI 0.603-0.767, P = 0.017). The results of time-dependent C-index for OS also showed that the nomogram had a better discriminative ability than that of TNM stage. The calibration curves of the nomogram showed good consistency between the probabilities and observed values. The decision curve analysis also revealed the potential clinical usefulness of the nomogram. Based on the cutoff value obtained from the nomogram, the proposed high-risk group had poorer OS than low-risk group (P < 0.0001).

CONCLUSIONS

The nomogram based on clinical characteristics and serological inflammation markers might be useful for outcome prediction of OTSCC patient.

Circulating Natural Autoantibodies to HER2-Derived Peptides Performed Antitumor Effects on Oral Squamous Cell Carcinoma

Natural autoantibodies play a crucial role in destruction of malignant tumors due to immune surveillance function. Epidermal growth factor receptor 2 (HER2) has been found to be highly expressed in a variety of epithelial tumors including oral squamous cell carcinoma (OSCC). The present study was thus undertaken to investigate the effect of anti-HER2 natural autoantibodies on OSCC. Compared with cancer-adjacent tissues, cancer tissues from OSCC patients exhibited higher HER2 expression especially in those with middle & advanced stage OSCC. Plasma anti-HER2 IgG levels examined with an enzyme-linked immunosorbent assay (ELISA) developed in-house showed differences between control subjects, individuals with oral benign tumor and patients with OSCC. In addition, anti-HER2 IgG-abundant plasma was screened from healthy donors to treat OSCC cells and to prepare for anti-HER2 intravenous immunoglobulin (IVIg). Both anti-HER2 IgG-abundant plasma and anti-HER2 IVIg could significantly inhibit proliferation and invasion of OSCC cells by inducing the apoptosis, and also regulate apoptosis-associated factors and epithelial-mesenchymal transition (EMT), respectively. Besides, the complement-dependent cytotoxicity (CDC) pathway was likely to contribute to the anti-HER2 IgG mediated inhibition of OSCC cells. After the HER2 gene was knocked down with HER2-specific siRNAs, the inhibitory effects on OSCC cell proliferation and apoptotic induction faded away. In conclusion, human plasma IgG, or IVIg against HER2 may be a promising agent for anti-OSCC therapy.

Pro-and anti-inflammatory effects of glucocorticoid Fluticasone on ovarian and immune functions in commercial-aged laying hens

Ovarian chronic inflammation has been created and extended in the laying hen mainly via increasing laying frequency and microbial infection, especially during the late stage of production period. This study was aimed to evaluate glucocorticoid (GC) Fluticasone as an anti-inflammatory agent on the gene expression of the ovarian pro-and anti-inflammatory mediators (follicular cyclooxygenases COX 1, 2, and cytokines), inflammatory responses of the immune system, ovarian functions (ovulation rate and follicular growths), and hormones in the commercial-aged laying hens. White Leghorn hens aged 92-weeks were used for four weeks to be supplemented by 2 ppm Fluticasone as an optimum dose obtained in a pre-trial base on ovulation rate. As compared to control, Fluticasone resulted in a significant decrease in the mRNA expression of COX-1 and pro-and anti-inflammatory cytokines, and increase in COX-2 mRNA expression and heterophil to lymphocyte ratio (P < 0.001). A significant reduction was observed in the ovulation rate, follicular size (P < 0.001), ovarian hormones, immunoglobulins, body weight, and food consummation (P ≤ 0.05) by administering GC Fluticasone. Although a relative anti-inflammatory improvement was created by Fluticasone in the ovarian condition, the administration of this glucocorticoid resulted in a considerable reduction in ovarian hormones and functions of commercial aged laying hens.

The stimulation and inhibition of beta-2 adrenergic receptor on the inflammatory responses of ovary and immune system in the aged laying hens

Background

Ovarian chronic inflammation has been known to incidence in the laying hen mainly via increasing laying frequency and microbial infection, especially during late stage of production period. This study was aimed to evaluate beta-2 adrenergic agonist (Beta-2 Adrenergic Agonist, BAA) Salmeterol and beta blocker (Beta Blocker, BB) Propranolol on the gene expression of the ovarian pro- and anti-inflammatory mediators, inflammatory responses of immune system, ovarian functions and, hormones in the laying hens on the late stage of production period. Forty-eight White Leghorn hens aged 92 weeks were used for 4 weeks to be supplemented by Salmeterol and Propranolol. Ovulation rate and follicular growth were determined based on laying frequency and ovarian visual evaluation, respectively; the mRNA expressions of follicular beta-2 adrenergic receptor (Beta-2 Adrenergic Receptor, β2ADR), cyclooxygenases (Cyclooxygenases, COX) 1 and 2, and cytokines were measured by real-time PCR. The plasma concentration of ovarian hormones, cellular, and humoral immune responses were measured via ELISA, heterophil to lymphocyte ratio (Heterophil to Lymphocyte ratio, H:L), and sheep red blood cell (Sheep Red Blood Cell, SRBC) test, respectively.

Results

As compared to control, both of BAA Salmeterol and BB Propranolol resulted in a significant decrease in the mRNA expression of β2ADR, cyclooxygenases, and pro- and anti-inflammatory cytokines (P < 0.01). A significant elevation was observed in the ovulation rate (P < 0.05), plasma estradiol content on both treated groups (P < 0.05), and the content of progesterone and was just significantly (P < 0.05) increased in Salmeterol group. H:L was reduced in BAA group (P < 0.05), and immunoglobulin (Ig) M was elevated in both treated hens, when compared to control. The results indicated that Salmeterol significantly increases body weight (P < 0.05).

Conclusion

The stimulation and inhibition of beta-2 adrenergic signaling could reduce ovarian inflammatory condition in addition to enhancing laying efficiency in the aged laying hens.

Current Understanding of Natural Antibodies and Exploring the Possibilities of Modulation Using Veterinary Models. A Review

Natural antibodies (NAb) are defined as germline encoded immunoglobulins found in individuals without (known) prior antigenic experience. NAb bind exogenous (e.g., bacterial) and self-components and have been found in every vertebrate species tested. NAb likely act as a first-line immune defense against infections. A large part of NAb, so called natural autoantibodies (NAAb) bind to and clear (self) neo-epitopes, apoptotic, and necrotic cells. Such self-binding antibodies cannot, however, be considered as pathogenic autoantibodies in the classical sense. IgM and IgG NAb and NAAb and their implications in health and disease are relatively well-described in humans and mice. NAb are present in veterinary (and wildlife) species, but their relation with diseases and disorders in veterinary species are much less known. Also, there is little known of IgA NAb. IgA is the most abundant immunoglobulin with essential pro-inflammatory and homeostatic properties urging for more research on the importance of IgA NAb. Since NAb in humans were indicated to fulfill important functions in health and disease, their role in health of veterinary species should be investigated more often. Furthermore, it is unknown whether levels of NAb-isotypes and/or idiotypes can and should be modulated. Veterinary species as models of choice fill in a niche between mice and (non-human) primates, and the study of NAb in veterinary species may provide valuable new insights that will likely improve health management. Below, examples of the involvement of NAb in several diseases in mostly humans are shown. Possibilities of intravenous immunoglobulin administration, targeted immunotherapy, immunization, diet, and genetic modulation are discussed, all of which could be well-studied using animal models. Arguments are given why veterinary immunology should obtain inspiration from human studies and why human immunology would benefit from veterinary models. Within the One Health concept, findings from veterinary (and wildlife) studies can be related to human studies and vice versa so that both fields will mutually benefit. This will lead to a better understanding of NAb: their origin, activation mechanisms, and their implications in health and disease, and will lead to novel health management strategies for both human and veterinary species.

Intravenous Immunoglobulin G Suppresses Heat Shock Protein (HSP)-70 Expression and Enhances the Activity of HSP90 and Proteasome Inhibitors

Intravenous immunoglobulin G (IVIgG) is approved for primary immunodeficiency syndromes but may induce anti-cancer effects, and while this has been attributed to its anti-inflammatory properties, IgG against specific tumor targets may play a role. We evaluated IVIgG alone, and with a Heat shock protein (HSP)-90 or proteasome inhibitor, using multiple myeloma and mantle cell lymphoma (MCL) cells in vitro, and with the proteasome inhibitor bortezomib in vivo. IVIgG inhibited the growth of all cell lines tested, induced G₁ cell cycle arrest, and suppressed pro-tumor cytokines including Interleukin (IL)-6, IL-8, and IL-10. Genomic and proteomic studies showed that IVIgG reduced tumor cell HSP70-1 levels by suppressing the ability of extracellular HSP70-1 to stimulate endogenous HSP70-1 promoter activity, and reduced extracellular vesicle uptake. Preparations of IVIgG were found to contain high titers of anti-HSP70-1 IgG, and recombinant HSP70-1 reduced the efficacy of IVIgG to suppress HSP70-1 levels. Combining IVIgG with the HSP90 inhibitor AUY922 produced superior cell growth inhibition and correlated with HSP70-1 suppression. Also, IVIgG with bortezomib or carfilzomib was superior to each single agent, and enhanced bortezomib's activity in bortezomib-resistant myeloma cells. Moreover, IVIgG reduced transfer of extracellular vesicles (EVs) to cells, and blocked transfer of bortezomib resistance through EVs. Finally, IVIgG with bortezomib were superior to the single agents in an in vivo myeloma model. These studies support the possibility that anti-HSP70-1 IgG contained in IVIgG can inhibit myeloma and MCL growth by interfering with a novel mechanism involving uptake of exogenous HSP70-1 which then induces its own promoter.

Content of anti-β-amyloid42 oligomers antibodies in multiple batches from different immunoglobulin preparations

Immunoglobulin preparations are one of the promising drugs for Alzheimer's disease (AD). Anti-β-amyloid (Aβ) oligomers antibodies in immunoglobulin preparations are considered to be critical for the therapeutic effect against Alzheimer's disease. However, the antibodies content in immunoglobulin preparations varies greatly. In order to determine which factor contributes to the difference of the antibodies content, the content of anti-Aβ oligomers antibodies in multiple batches of immunoglobulin preparations from two manufacturers were measured by enzyme-linked immunosorbent assay. The results showed that no significant difference was found in the antibodies content among different bathes of normal immunoglobulin preparations prepared by the same process from the same manufacturer, whereas significant difference was found in the antibodies content between normal immunoglobulin preparations prepared by ethanol fractionation and those by chromatography process from the same manufacturer. In addition, significant variation existed in the antibodies content between normal immunoglobulin preparations and specific immunoglobulin preparations that are produced by plasma pool of immunized donors. Based on analysis of these results, the preparation process and raw plasma could be the main contributing factors affecting the content of anti-Aβ oligomers antibodies in immunoglobulin preparations. This finding might help to develop AD-specific immunoglobulin preparation containing higher content of anti-Aβ oligomers antibodies.

The level of natural autoantibodies to IFN-gamma in varicella infection treated with antiviral drug Anaferon for children: A pilot study

Natural circulating antibodies (NAbs) to endogenous regulators have shown to be potential biomarkers in medicine. Due to the lack of reliable assays, only few of them have been well studied. To employ NAbs as biomarkers, an evaluation of changes over the course of a treatment is required. This paper describes our work to analyze the dynamics of NAbs titer to interferon-gamma (IFN-γ) among healthy children of different age and in patients with varicella infection receiving an antiviral drug Anaferon for children (AC, the API are highly diluted antibodies to IFN-γ) in comparison with placebo, and to correlate the findings with the treatment results. IFN-γ plays an essential role during varicella infection, and this fact causes the consequent increase of NAbs to IFN-γ level. The mean anti-IFN-γ NAbs level in the healthy volunteer group was 101 × 10³ U/ml (age: 0-15 years), which was significantly lower than the mean pre-treatment value in patients with varicella infection 167 × 10³ U/ml (age: 3-17 years). In the AC group, the NAbs level observed on days 5 and 10 decreased significantly to a level of 154 × 10³ U/ml, whereas in the placebo group it continued to rise in a time-dependent manner reaching 229 × 10³ U/ml on day 10. Our findings suggest that treatment with AC is characterized by "normalization" of the anti-IFN-γ NAbs levels in patients with varicella infection.

Evaluation of the frequency of CD5+ B cells as natural immunoglobulin M producers and circulating soluble CD5 in patients with bladder cancer

Bladder cancer is the most common malignancy of the genitourinary tract. It is the fourth most common malignancy in men and the fifth most common malignancy in the general population, with a high recurrence rate. CD5⁺ B lymphocytes are a subset of B lymphocytes, which contribute to innate immune responses. These cells are involved in the spontaneous production of self-reactive natural antibodies. On the other hand, natural antibodies can recognize tumor-associated antigens, including proteins or carbohydrates, and eliminate these cells in a complement-dependent manner or via induction of apoptosis. Besides surface CD5, the soluble form of this molecule is involved in the regulation of immune system. Considering the role of CD5⁺ B cells in the production of natural immunoglobulin M (IgM) and role of these antibodies in antitumor responses, in this study, we aimed to investigate the frequency of CD5 in B cells and to evaluate the diagnostic potential of these cells and also soluble CD5 (sCD5) in patients with bladder cancer. Blood specimens were collected from 40 patients with bladder cancer, who were referred to Sina Hospital in Tehran, IRAN. The levels of CD5⁺ and CD5^- B lymphocytes were measured in the peripheral blood via flow cytometry, and the levels of sCD5 and total IgM were investigated in the serum by ELISA and nephlometry techniques, respectively. The frequency of CD5⁺ and CD5^- B cells was significantly lower in patients, compared with the healthy controls. Detectable levels of sCD5 were found in two patients (5%), while total IgM showed no significant difference between the patient and control groups. The present results suggest that B cell subsets may be affected by malignancy. Therefore, further research is needed to identify B cells and their soluble markers for diagnosis of patients with bladder cancer.

Evaluation of the frequency of CD5+ B cells as natural immunoglobulin M producers and circulating soluble CD5 in patients with bladder cancer

Bladder cancer is the most common malignancy of the genitourinary tract. It is the fourth most common malignancy in men and the fifth most common malignancy in the general population, with a high recurrence rate. CD5⁺ B lymphocytes are a subset of B lymphocytes, which contribute to innate immune responses. These cells are involved in the spontaneous production of self-reactive natural antibodies. On the other hand, natural antibodies can recognize tumor-associated antigens, including proteins or carbohydrates, and eliminate these cells in a complement-dependent manner or via induction of apoptosis. Besides surface CD5, the soluble form of this molecule is involved in the regulation of immune system. Considering the role of CD5⁺ B cells in the production of natural immunoglobulin M (IgM) and role of these antibodies in antitumor responses, in this study, we aimed to investigate the frequency of CD5 in B cells and to evaluate the diagnostic potential of these cells and also soluble CD5 (sCD5) in patients with bladder cancer. Blood specimens were collected from 40 patients with bladder cancer, who were referred to Sina Hospital in Tehran, IRAN. The levels of CD5⁺ and CD5^- B lymphocytes were measured in the peripheral blood via flow cytometry, and the levels of sCD5 and total IgM were investigated in the serum by ELISA and nephlometry techniques, respectively. The frequency of CD5⁺ and CD5^- B cells was significantly lower in patients, compared with the healthy controls. Detectable levels of sCD5 were found in two patients (5%), while total IgM showed no significant difference between the patient and control groups. The present results suggest that B cell subsets may be affected by malignancy. Therefore, further research is needed to identify B cells and their soluble markers for diagnosis of patients with bladder cancer.

Serum anti-GAPDH autoantibody levels reflect the severity of cervical lesions: A potential serum biomarker for cervical cancer screening

Recent studies have indicated that a certain level of autoantibodies may be essential for maintaining good health as well as preventing cancer development, and that the levels of serum autoantibodies can decline during malignant progression. The aim of the present study was to identify such an autoantibody-based biomarker for screening cervical lesions. An autoantigen reactive with healthy female sera was detected in the cytosolic fraction of HeLa cells, a cervical cancer cell line, and identified. Serum immunoglobulin (Ig)-G and IgM levels against the purified autoantigen in normal, cervical intraepithelial neoplasias (CINs) I, II and III, and cervical cancer were compared using ELISAs. The autoantigen in HeLa cells was identified to be GAPDH. The serum levels of anti-HeLa-GAPDH IgG decreased with increasing severity of cervical lesions, and similar decreases in IgM levels were revealed. Notably, the anti-HeLa-GAPDH IgG level was discovered to discriminate cervical cancer from normal samples with 80.0% sensitivity and 96.6% specificity. The serum anti-HeLa-GAPDH autoantibody level, as a single parameter, is a promising serum biomarker for screening cervical lesions.

Mature naïve B cells are retained in the placental intervillous blood and positively associate with specific chemokines in full-term healthy pregnancy

PROBLEM

Circulating B-cell numbers are lower during pregnancy compared with non-pregnant women, but the underlying reasons for this are unknown. Pregnancy-related hormones could influence B-cell lymphopoiesis in the bone marrow, but B cells may also be recruited to the placenta. To investigate the latter, we examined whether the proportions of total B cells and B cells at different maturational stages in placental intervillous blood (IVB) differ compared with peripheral blood (PB).

METHOD OF STUDY

From 23 paired samples of PB and IVB following full-term healthy pregnancies, total B cells and immature/transitional, mature/naïve, and memory B cells were identified by flow cytometry. Chemokine levels in blood were analyzed using a Luminex assay. Placental explant-derived supernatant was assayed for B-cell chemotactic activity.

RESULTS

The proportions of total B cells and mature/naïve B cells were significantly higher in IVB relative to PB, while the fractions of immature/transitional cells and memory B cells were higher in PB. Multivariate factor analysis demonstrated that a specific chemokine profile in IVB, including CCL20, positively associated with higher proportions of mature/naïve B cells in the intervillous space. All B cells expressed CCR6, the corresponding receptor for CCL20, but the intensity of CCR6 expression was significantly higher in mature/naïve B cells relative to immature/transitional B cells. Migration assays showed that placental explant-derived supernatants attract B cells.

CONCLUSION

These results indicate that B cells, and mature/naïve B cells in particular, are retained in the intervillous blood in response to certain chemokines produced by the placenta during late healthy pregnancy.

Maternal Transfer of Natural (Auto-) Antibodies in Chickens

The presence and relative levels (titers) of IgM and IgG natural antibodies (NAb) binding keyhole limpet hemocyanin (KLH), and natural (auto-) antibodies (N(A)Ab) binding salmon double-stranded DNA (dsDNA), (oxidated-) phosphatidyl (phosphoryl) choline-conjugated bovine serum albumin (PC-BSA), PC-conjugated ovalbumin (PC-OVA), and OVA, respectively, were studied in adult hen plasma, egg yolk, egg albumen, plasma of their hatchlings, and in 8-day-old chick plasma. Birds and eggs were from 2 lines divergently selected for high or low NAb levels binding KLH. This study aimed to determine 1) correlated phenotypic responses of selection for NAb to KLH, 2) transfer of maternal NAb and N(A)Ab via egg compartments, 3) levels of likely maternal NAb and N(A)Ab in hatchlings and 8-day-old chicks, and 4) whether a composite trait: IgM anti-PC-BSA/IgG anti-dsDNA ratio in the compartments could be used as a parameter for health or immune status. NAb and N(A)Ab to all tested antigens were found in adult hens, but low or no levels were found for IgM in yolk and IgG in albumen. Depending on the antigen, NAb and N(A)Ab were found in hatchlings and day 8 birds. Divergent selection and breeding based on NAb binding KLH affected antibody titers of almost all antigens in almost all compartments, in a similar way. Maternal transfer of NAb and N(A)Ab from the adult hen to offspring was via specific routes for specific antigens and isotypes, especially for IgG as suggested by cluster analyses and significant correlations. There was little indication of production of new NAb and N(A)Ab to the studied antigens in either the egg compartments or the hatchlings. A composite trait of IgM PC-BSA/IgG dsDNA ratio was as yet not indicative for immune status, as no significant differences were found between the lines for all compartments. In conclusion, hens provide neonatal chickens with natural (self-) binding IgG antibodies that have been proposed to perform homeostatic functions during the period in which neonates do not produce these antibodies themselves.

Natural antibodies - facts known and unknown

In contrast to adaptive antibodies, natural antibodies are present in a non-immunised organism from birth, and they do not include anti-Gal antibodies and/or anti-Gal natural antibodies, which are developed as a result of the effect of the α-Gal epitope and physiological flora. Natural antibodies are the first line of the organism’s defence before the formation of the immunity created via the stimulation of elements that determine specific and non-specific immunity. This is especially important in the case of infants. Despite the fact that natural antibodies differ in their function from adaptive antibodies, they are polyreactive and they detect autoantigens and new antigenic determinants. Natural antibodies are formed from the subpopulation of B lymphocytes, mainly B1 lymphocytes and B lymphocytes of the marginal zone. This phenomenon is supported by the fact that when the quantity of these cells in the organism decreases, which happens with age, the level of natural antibodies also decreases and the risk of illnesses of old age becomes higher. During ontogenesis, these antibodies participate in many physiological processes, including the “support” of the immune system and homeostasis, the prevention of inflammation, infections and other pathological states, such as autoimmune and cardiovascular diseases, or the process of carcinogenesis. The best known natural antibody is IgM, but the role of IgGs and IgAs is also considered important. Nowadays, many researchers also mention intravenous immunoglobulins, which are used in the treatment of numerous illnesses, and there are discussions on the possibility of increasing their potential if they were based on natural antibodies.

Elevated Autoantibodies in Subacute Human Spinal Cord Injury Are Naturally Occurring Antibodies

Spinal cord injury (SCI) results in long-term neurological and systemic consequences, including antibody-mediated autoimmunity, which has been related to impaired functional recovery. Here we show that autoantibodies that increase at the subacute phase of human SCI, 1 month after lesion, are already present in healthy subjects and directed against non-native proteins rarely present in the normal spinal cord. The increase of these autoantibodies is a fast phenomenon–their levels are already elevated before 5 days after lesion–characteristic of secondary immune responses, further supporting their origin as natural antibodies. By proteomics studies we have identified that the increased autoantibodies are directed against 16 different nervous system and systemic self-antigens related to changes known to occur after SCI, including alterations in neural cell cytoskeleton, metabolism and bone remodeling. Overall, in the context of previous studies, our results offer an explanation to why autoimmunity develops after SCI and identify novel targets involved in SCI pathology that warrant further investigation.

Divergent Roles of Antiself Antibodies during Infection

Antiself antibodies are most commonly associated with autoimmune disorders, but a large body of evidence indicates that they are also present in numerous infectious diseases. These autoimmune antibodies appear transiently during infection with a number of viruses, bacteria, and parasites and in some cases have been associated with the development of autoimmune disorders that develop after infection has been cleared. Traditionally these infection-associated autoantibodies are considered an erroneous byproduct of a legitimate immune response, but their possible role in the clearance of microbes and infected cells or inhibition of host-cell invasion suggests that they may be present because of their beneficial protective role against various infections.

Alteration of circulating natural autoantibodies to CD25-derived peptide antigens and FOXP3 in non-small cell lung cancer

Natural autoantibody is a key component for immune surveillance function. Regulatory T (Treg) cells play indispensable roles in promoting tumorigenesis via immune escape mechanisms. Both CD25 and FOXP3 are specific markers for Treg cells and their natural autoantibodies may be involved in anticancer activities. This work was designed to develop an in-house enzyme-linked immunosorbent assay (ELISA) to examine plasma natural IgG against CD25 and FOXP3 in non-small cell lung cancer (NSCLC). Compared with control subjects, NSCLC patients had significantly higher levels of plasma IgG for CD25a (Z = -8.05, P < 0.001) and FOXP3 (Z = -4.17, P < 0.001), lower levels for CD25b (Z = -3.58, P < 0.001), and a trend toward lower levels for CD25c (Z = -1.70, P = 0.09). Interestingly, the anti-CD25b IgG assay had a sensitivity of 25.0% against a specificity of 95.0% in an early stage patients (T1N0M0) who showed the lowest anti-CD25b IgG levels among 4 subgroups classified based on staging information. Kaplan-Meier survival analysis showed that patients with high anti-FOXP3 IgG levels had shorter survival than those with low anti-FOXP3 IgG levels (χ2 = 3.75, P = 0.05). In conclusion, anti-CD25b IgG may be a promising biomarker in terms of screening individuals at high risk of lung cancer.

An idiopathic thrombocytopenic purpura with polyneuropathy

Concurrent association of idiopathic thrombocytopenic purpura (ITP) and peripheral neuropathy is a rare condition. There are only few case reports published concerning peripheral neuropathy with ITP. One of the etiopathogenetic mechanisms proposed is intraneural hemorrhage, but the pathogenesis is not fully understood. Autoimmune nature with common antibodies to the platelets and the nerve´s myelin sheath should also be considered. Here we describe a 47-year-old woman, with a family history of autoimmune diseases. She was diagnosed 2 years ago with ITP and later developed a chronic combined inflammatory demyelinating polyneuropathy. Treatment with high-dose steroids was initiated with a poor response. The patient showed a clear improvement in platelet count and in the peripheral neuropathy symptoms when treatment with intravenous immunoglobulin was administered. Common etiologic mechanism of the two diseases should be considered, both, because of the simultaneous time of development and a similar response to intravenous immunoglobulin treatment.

Significance of tumor-associated autoantibodies in the early diagnosis of lung cancer

OBJECTIVES

Autoantibodies tumor-associated antigens (TAAs) could be a valuable tool for the diagnosis or early detection of cancer due to their relatively high specificity and stability. The purpose of this study is to detect the level of tumor-associated autoantibodies in lung cancer and assess the diagnostic potential of autoantibodies in screening strategy for early stage lung cancer.

MATERIALS AND METHODS

Levels of tumor-associated autoantibodies (AAbs) were measured against a panel of seven TAAs (p53, PGP9.5, SOX2, GAGE7, GBU4-5, CAGE and MAGEA1) in 397 patients with pulmonary lesions (305 with newly diagnosis of NSCLC, 47 with SCLC and 45 with benign nodule) and 74 control persons without any nodules in the lung after chest MDCT scan. The sensitivity, specificity for patients and control persons, positive rate of the panel in different pathology, stage, size of lesion, age and gender were compared and analyzed.

RESULTS

The AAbs panel could distinguish malignant lesions from benign lesions and control people, with sensitivity of 56.53% and specificity of 91.60%. The specificity could be further increased to 95.80%, when combined with CT. The AAbs also showed high diagnostic value of malignant nodule, and it would be a new method for judgment of malignant nodules that are less than 8 mm in diameter. No significant differences were seen based on pathology, NSCLC stages, tumor size, age or gender.

CONCLUSION

This assay confirms the value of AAbs panel as a diagnostic tool combined with CT scan.

Depressive, anxiety and hypomanic symptoms in schizophrenia may be driven by tryptophan catabolite (TRYCAT) patterning of IgA and IgM responses directed to TRYCATs

The aim of this study was to delineate the associations between the tryptophan catabolite (TRYCAT) pathway and affective symptoms in schizophrenia. Towards this end we measured immunoglobulin (Ig)A and IgM responses to relatively noxious TRYCATs, namely quinolinic (QA), xanthurenic (XA), picolinic (PA) acid and 3-OH-kynurenine (3HK), and generally protective TRYCATs, namely anthranilic (AA) and kynurenic (KA) acid in 80 patients with schizophrenia and 40 healthy controls. The Hamilton Rating Scale for Depression (HDRS) and anxiety (HAMA), Young Mania Rating Scale (YMRS) as well as the Positive and Negative Symptoms Scale of Schizophrenia (PANSS) were measured. Depression, anxiety and hypomanic as well as negative and positive symptoms were associated with increased IgA responses to PA. Increased IgA responses to XA were associated with anxiety, hypomanic and negative symptoms. Moreover, depressive, anxiety, hypomanic and negative symptoms were characterized by increased IgA responses to the noxious (XA+3HK+QA+PA)/protective (AA+KA) TRYCAT ratio. All symptom dimensions were associated with increased IgM responses to QA, while depressive, anxiety, positive and negative symptoms were accompanied by lowered IgM responses to 3HK. Hypomanic symptoms were additionally accompanied by lowered IgM responses to AA, and negative symptoms by increased IgM responses to KA. In conclusion, both shared and distinct alterations in the activity of the TRYCAT pathway, as well as its regulatory factors and consequences, may underpin affective and classical psychotic symptoms of schizophrenia. Increased mucosa-generated production of noxious TRYCATs, especially PA, and specific changes in IgM-mediated regulatory activities may be associated with the different symptom dimensions of schizophrenia.

Low Levels of IgG Recognizing the α-1-Antitrypsin Peptide and Its Association with Taiwanese Women with Primary Sjögren's Syndrome

The aim of this study was to examine oxidative stress and low level of α-1-antitrypsin (A1AT) in primary Sjögren’s syndrome (pSS), and evaluate the associated autoreactivity against unmodified and their 4-hydroxy-2-nonenal (HNE)-modified peptides with pSS. Two differentially expressed proteins, α-1-acid glycoprotein 1 (A1AG1) and A1AT, exhibited 2-fold differences, and their HNE modifications were identified by depleted-albumin and immunoglobulin G (IgG) serum protein, in-solution digestion, in-gel digestion, and nano-liquid chromatography–tandem mass spectrometry (nano-LC-MS/MS) from pSS patients and age-matched healthy controls (HCs). Furthermore, levels of proteins, confirmation of HNE modifications, HNE-protein adducts and autoreactivity against unmodified and their HNE-modified peptides were further validated. Levels of the HNE-protein adduct and A1AG1 were significantly higher in pSS patients than HCs, but levels of A1AT were significantly lower in pSS patients compared to HCs. Only the HNE modification of A1AT was confirmed. Our study suggests that elevated HNE-protein adduct, oxidative stress, level (odds ratio (OR) 4.877, p = 0.003), lowered A1AT level (OR 3.910, p = 0.010) and a decreased level of anti-A1AT^50–63 IgG (OR 3.360, p = 0.010) showed an increased risk in pSS patients compared to HCs, respectively.

Detection of circulating natural antibodies to inflammatory cytokines in type-2 diabetes and clinical significance

Background

Inflammatory cytokines have been demonstrated to be involved in developing insulin resistance and type-2 diabetes (T2D). Natural antibodies in the circulation have protective effects on common diseases in humans. The present study was thus designed to test the hypothesis that natural antibodies against inflammatory cytokines could be associated with T2D.

Methods

An enzyme-linked immunosorbent assay (ELISA) was developed in-house to detect plasma IgG against peptide antigens derived from interleukin 1α (IL1α), IL1β, IL6, IL8 and tumor necrosis factor-α (TNF-α) in 200 patients with T2D and 220 control subjects.

Results

Binary regression showed that compared with control subjects, T2D patients had a decreased level of plasma anti-IL6 IgG (adjusted r²=0.034, p=0.0001), anti-IL8 IgG (adjusted r²=0.021, p=0.002) and anti-TNF-α IgG (adjusted r²=0.017, p=0.003). Female patients mainly contributed to decreased levels of anti-IL6 IgG (adjusted r²=0.065, p=0.0008) and anti-IL8 IgG (adjusted r²=0.056, p=0.003), while male patients mainly contributed to decreased anti-TNF-α IgG levels (adjusted r²=0.024, p=0.005). ROC curve analysis revealed a sensitivity of 16.5% against specificity of 95.5% for anti-IL6 IgG assay and a sensitivity of 19.5% against specificity of 95.9% for anti-IL8 IgG assay. Glycated hemoglobin levels measured after 6-month glucose-lowering treatment appeared to be inversely correlated with plasma anti-IL1α IgG (r=-0.477, df=17, p=0.039) and anti-IL6 IgG (r=-0.519, df=17, p=0.023) although such correlation failed to survive the Bonferroni correction.

Conclusions

Deficiency of natural IgG against inflammatory cytokines is likely to be a risk factor for T2D development and detection of such antibodies may be useful for personalized treatment of the disease.

Electronic supplementary material

The online version of this article (10.1186/s12950-017-0171-6) contains supplementary material, which is available to authorized users.

IgM-mediated autoimmune responses to oxidative specific epitopes, but not nitrosylated adducts, are significantly decreased in pregnancy: association with bacterial translocation, perinatal and lifetime major depression and the tryptophan catabolite (TRYCAT) pathway

Immunoglubulin (Ig)M responses directed to oxidative specific epitopes (OSEs) and nitric oxide (NO)-adducts are significantly associated with major depression and physio-somatic symptoms. End of term serum IgM responses to OSEs and NO-adducts were assayed in pregnant women with (n = 24) and without prenatal depression (n = 25) as well as in 24 non-pregnant women. Associations of IgM/IgA responses to Gram-negative gut commensal bacteria (leaky gut index) and IgA/IgM responses to tryptophan catabolites (TRYCATs) were analyzed. IgM responses to OSEs, but not NO-adducts, were significantly reduced at the end of term. There were no significant associations between IgM responses to OSEs and perinatal depression, whilst IgM responses to NO-adducts, especially NO-cysteinyl, were significantly associated with a lifetime major depression. IgM responses to OSEs and NO-cysteinyl were significantly associated with IgA/IgM responses to Gram-negative bacteria, especially Morganella morganii, Klebsiella pneumoniae and Citrobacter koseri. IgM responses to NO-adducts and OSEs, especially malondialdehyde and myristic acid, and C-reactive protein (CRP) were inversely associated with TRYCAT pathway activity, whilst a lifetime depression and Pseudomonas putida were positively associated. The attenuation of natural IgM-mediated responses to OSEs at the end of term may indicate lowered activity of this part of the compensatory (anti-)inflammatory reflex system and may be partly explained by lowered bacterial translocation. Increased IgM responses to NO-cysteinyl is a biomarker of lifetime depression and may be induced by bacterial translocation. Natural IgM-mediated autoimmune responses, increased nitrosylation and higher CRP levels may have negative regulatory effects on the TRYCAT pathway.

Immunization enhances the natural antibody repertoire

The role of immunization in the production of antibodies directed against immunogens is widely appreciated in laboratory animals and in humans. However, the role of immunization in the development of "natural antibodies" has not been investigated. Natural antibodies are those antibodies present without known history of infection or immunization, and react to a wide range of targets, including "cryptic" self-antigens that are exposed upon cell death. In this study, the ability of immunization to elicit the production of natural antibodies in laboratory rats was evaluated. Laboratory rats were immunized with a series of injections using peanut extracts (a common allergen), a high molecular weight protein conjugated to hapten (FITC-KLH), and a carbohydrate conjugated to hapten (DNP-Ficall). Significantly greater binding of antibodies from immunized animals compared to controls was observed to numerous autologous organ extracts (brain, kidney, liver, lung, prostate, and spleen) for both IgM and IgG, although the effect was more pronounced for IgM. These studies suggest that immunization may have at least one unforeseen benefit, enhancing networks of natural antibodies that may be important in such processes as wound repair and tumor surveillance. Such enhancement of natural antibody function may be particularly important in Western society, where decreased exposure to the environment may be associated with a weakened natural antibody repertoire.

Correlation between elevated platelet count and immunoglobulin levels in the early convalescent stage of Kawasaki disease

Kawasaki disease (KD) may be an acute systemic immune-mediated disease which occurs after infection of unknown KD pathogen(s). The aim of this study is to evaluate the changes in platelet count and immunoglobulin (Ig) levels (IgG, IgM, IgA, and IgE) during hospitalization.Forty-three patients with complete KD who received intravenous Ig at 2 g/kg were enrolled in South Korea. The platelet count and Ig levels of the patients were examined twice at presentation and around discharge (mean 6.2 ± 2.4 days apart) and the relationships between platelet level and Ig levels were evaluated.The mean patient age was 31 ± 18 months; 28 patients were male and 15 were female. The values of all parameters measured, with the exception of IgE, were significantly increased at the second examination compared with their values at presentation. These values gradually increased over time after fever onset, over periods ranging from 2 to 16 days. The extent by which platelet levels increased over these 2 time points was correlated with the extents by which IgG (P < .01), IgM (P < .01), and IgA levels (P = .01) increased.Both the platelet count and the Ig (IgG, IgM, and IgA) levels increased with a correlation each other during the early convalescent stage of KD. This finding suggests that all Ig subtypes except IgE and platelets may be involved in the recovery from KD and that the extent of increased parameters may reflect the degree of systemic inflammation in acute KD.

The potential of intravenous immunoglobulins for cancer therapy: a road that is worth taking?

Much has been learned recently about the role of immunoglobulins as effector molecules of the adaptive immunity and as active elements in the maintenance of immune homeostasis. The increasing number of pathologies where intravenous immunoglobulins (IVIg) display a beneficial action illustrates their therapeutic relevance. Considering recent findings on the ability of IVIg to modulate macrophage polarization, herein we review evidences on the antitumoral activity of IVIg. Fragmentary and nonconclusive, available evidences are just suggestive of the potential of IVIg in antitumoral therapy, but encourage for the generation of additional evidences through well-designed clinical trials, and for additional studies to address the molecular effects of IVIg as a means to avoid the extrapolation of data gathered from animal models.

Deficit Schizophrenia Is Characterized by Defects in IgM-Mediated Responses to Tryptophan Catabolites (TRYCATs): a Paradigm Shift Towards Defects in Natural Self-Regulatory Immune Responses Coupled with Mucosa-Derived TRYCAT Pathway Activation

Deficit schizophrenia is accompanied by mucosa-associated activation of the tryptophan catabolite (TRYCAT) pathway, as indicated by increased IgA responses to noxious (NOX) TRYCATs, but not regulatory or protective (PRO) TRYCATs, suggesting increased neurotoxic, excitotoxic, inflammatory, and oxidative potential. No previous studies examined IgM-mediated autoimmune responses to the TRYCAT pathway in deficit versus nondeficit schizophrenia. We measured IgM responses to NOX TRYCATs, namely, quinolinic acid (QA), 3-OH-kynurenine (3HK), picolinic acid (PA), and xanthurenic (XA) acid, and PRO TRYCATs, including kynurenic acid (KA) and anthranilic acid (AA), in 40 healthy controls and 40 deficit and 40 nondeficit schizophrenic patients. We computed the IgM responses to NOX (QA + PA + 3HK + XA)/PRO (AA + KA) ratio and ∆ differences in IgA - IgM TRYCAT values and NOX/PRO ratio. Deficit schizophrenia is characterized by significantly attenuated IgM responses to all TRYCATs and NOX/PRO ratio and highly increased ∆IgA - IgM NOX/PRO ratio as compared to nondeficit schizophrenia and healthy controls. The negative symptoms of schizophrenia are significantly and positively associated with increased IgM responses directed against the KA/3HK ratio and ∆IgA - IgM NOX/PRO ratio. The findings support the view that deficit schizophrenia is a distinct subtype of schizophrenia that may be significantly discriminated from nondeficit schizophrenia. Deficit schizophrenia is accompanied by a highly specific defect in IgM isotype-mediated regulatory responses directed to the TRYCAT pathway. Lowered IgM regulatory responses together with mucosa-derived activation of the TRYCAT pathway may contribute to neuroprogression, negative symptoms, and deficit schizophrenia. All in all, a highly specific defect in the compensatory (anti-)inflammatory reflex system (CIRS), namely, natural IgM-mediated regulatory responses, may underpin deficit schizophrenia.

Monomeric Immunoglobulin A from Plasma Inhibits Human Th17 Responses In Vitro Independent of FcαRI and DC-SIGN

Circulating immunoglobulins including immunoglobulin G (IgG) and IgM play a critical role in the immune homeostasis by modulating functions of immune cells. These functions are mediated in part by natural antibodies. However, despite being second most abundant antibody in the circulation, the immunoregulatory function of IgA is relatively unexplored. As Th17 cells are the key mediators of a variety of autoimmune, inflammatory, and allergic diseases, we investigated the ability of monomeric IgA (mIgA) isolated from pooled plasma of healthy donors to modulate human Th17 cells. We show that mIgA inhibits differentiation and amplification of human Th17 cells and the production of their effector cytokine IL-17A. mIgA also suppresses IFN-γ responses under these experimental conditions. Suppressive effect of mIgA on Th17 responses is associated with reciprocal expansion of FoxP3-positive regulatory T cells. The effect of mIgA on Th17 cells is dependent on F(ab′)₂ fragments and independent of FcαRI (CD89) and DC-SIGN. Mechanistically, the modulatory effect of mIgA on Th17 cells implicates suppression of phosphorylation of signal transducer and activator of transcription 3. Furthermore, mIgA binds to CD4⁺ T cells and recognizes in a dose-dependent manner the receptors for cytokines (IL-6Rα and IL-1RI) that mediate Th17 responses. Our findings thus reveal novel anti-inflammatory functions of IgA and suggest potential therapeutic utility of mIgA in autoimmune and inflammatory diseases that implicate Th17 cells.

The effect of Intravenous Immunoglobulin (IVIG) on \textit{ex vivo} activation of human leukocytes

INTRODUCTION

Intravenous immunoglobulin (IVIG) has been widely used to treat various conditions, including inflammatory and autoimmune diseases. IVIG has been shown to have a direct influence on neutrophils, eosinophils and lymphocytes. However, many aspects IVIG's effect on neutrophils activation still remain unknown.

OBJECTIVE

To evaluate the effect of IVIG on PMA-induced activation of neutrophils, with and without priming with TNF-α, in a series of in vitro experiments performed on whole blood.

RESULTS

Our data coincided with well-known literature indicating that the effect of phorbol 12-myristate 13-acetate (PMA) on human leukocytes includes activation of neutrophils, monocytes and eosinophils, increase of chemiluminescence (CL) and induction of netosis, resulting in assembly of traps. In presence of IVIG (10 mg/mL), CL was reduced by 25% in response to PMA compared to PMA-induced leukocyte activation without IVIG. Decreasing IVIG concentration to 1 mg/mL and below did not inhibit PMA-induced activation of CL.PMA-induced activation after TNF-α priming resulted in approximately 50% increase of amplitude of CL response to PMA. Moreover, maximum CL was reached by minute 5, which was more rapid than in the absence of TNF-α-priming (in this case maximum CL was reached by minute 15).The IVIG concentrations did not affect morphological changes of leukocytes after sequential addition of TNF-α and PMA. IVIG had no effect on leukocyte content and on PMA-induced CL of primed leukocytes.Addition of IVIG under TNF-α priming significantly increased the number of traps in the smears in response to PMA activation. Of note, such an increase in the number of traps was depended on the IVIG concentration in plasma.

CONCLUSION

In conclusion, we suggest that IVIG is able to reduce the degradation of traps under priming with TNF-α. Moreover, IVIG might switch the activation of primed leukocytes to netosis.

Study of natural IgG antibodies against vascular endothelial growth factor receptor 1 in hepatocellular carcinoma

Natural antibodies have been found to have anti-tumorigenic function. This study was designed to investigate whether natural IgG antibodies against vascular endothelial growth factor receptor 1 (VEGFR1) could suppress the growth of hepatocellular carcinoma (HCC) cells. Three HCC cell lines and A549 lung cancer cells were used for this study. They were grown, respectively, with human plasma positive or negative for anti-VEGFR1 IgG. Cell viability, apoptosis and VEGFR1 gene expression were examined. Three patients with HCC were recruited for a case study. The results showed that plasma anti-VEGFR1 IgG significantly inhibited the proliferation of all three HCC cell lines but not A549 cell line; the proportions of apoptotic cells were significantly higher in HCC cells treated with anti-VEGFR1 IgG positive plasma than those treated with IgG negative plasma. The expression of the VEGFR1 gene was significantly higher in HCC cells than A549 cells. Of three HCC patients who received transfusion of anti-VEGFR1 IgG positive plasma, two cases with stage B showed a good response to the treatment but one with distant metastasis did not. Human plasma IgG against VEGFR1 may be a promising agent for anti-HCC therapy.

Targeting Inflammation in So-Called Acute Kidney Injury

The clinical category of acute kidney injury includes a wide range of completely different disorders, many with their own pathomechanisms and treatment targets. In this review we focus on the role of inflammation in the pathogenesis of acute tubular necrosis (ATN). We approach this topic by first discussing the role of the immune system in the different phases of ATN (ie, early and late injury phase, recovery phase, and the long-term outcome phase of an ATN episode). A more detailed discussion focuses on putative therapeutic targets among the following mechanisms and mediators: oxidative stress and reactive oxygen species-related necroinflammation, regulated cell death-related necroinflammation, immunoregulatory lipid mediators, cytokines and cytokine signaling, chemokines and chemokine signaling, neutrophils and neutrophils extracellular traps (NETs) associated neutrophil cell death, called NETosis, extracellular histones, proinflammatory mononuclear phagocytes, humoral mediators such as complement, pentraxins, and natural antibodies. Any prioritization of these targets has to take into account the intrinsic differences between rodent models and human ATN, the current acute kidney injury definitions, and the timing of clinical decision making. Several conceptual problems need to be solved before anti-inflammatory drugs that are efficacious in rodent ATN may become useful therapeutics for human ATN.

Detection of Natural Antibodies and Serological Diagnosis of Pneumococcal Pneumonia Using a Bead-Based High-Throughput Assay

Surface-exposed proteins of pathogenic bacteria play a critical role during infections . The vast majority of these molecules are able to trigger strong immune responses. Measuring the humoral immune response against pathogenic bacteria through less-time consuming tests is necessary to reduce the window time for the diagnosis of diseases that may be associated with high morbidity and mortality rates. Due to the multiplex setup, Luminex xMAP^® technology allows analysis of immune responses against many antigens in a single assay. Therefore, less volumes of sera samples are needed and inter assay coefficient of variation is much lower in comparison with other immunoassays. With this methodology, the carboxyl groups on the surface of the polystyrene microspheres must first be activated with a carbodiimide derivative prior to coupling antigens . After the antigen is coupled to a microsphere , different microspheres (all having a unique color) can be combined whereafter the presence of specific antibodies directed against the different antigens in sera can be determined simultaneously. The platform here described can also be useful for epidemiological surveillance programs and vaccine studies.

Antibody repertoire profiling with mimotope arrays

Large-scale profiling and monitoring of antibody repertoires is possible through next generation sequencing (NGS), phage display libraries and microarrays. These methods can be combined in a pipeline, which ultimately maps the antibody reactivities onto defined arrays of structures - peptides or carbohydrates. The arrays can help analyze the individual specificities or can be used as complex patterns. In any case, the targets recognized should formally be considered mimotopes unless they are proven to be epitopes driving the antibody synthesis. Here, the advantages and disadvantages of the major profiling techniques as well as their current and future application in disease prediction and vaccination are discussed.

A Special Connection between γδ T Cells and Natural Antibodies?

Natural antibodies (NAbs) play an important role in early host defense, autophagy and tissue remodeling, and in immune regulation. They arise spontaneously (without specific immunization), and are already present at birth. NAbs are produced by B1 B cells, MZ B cells and other B cell types. They include all major Ig subclasses but IgM antibodies are prevalent, especially early in development. NAbs may be poly-specific, recognize particular auto-antigens, or detect neo-determinants such as those exposed during apoptosis or generated by oxidation. NAbs do not require cognate T cell help but depend on soluble mediators produced by T cells. Our recent studies suggest that γδ T cells may have a special relationship with NAbs, and play a prominent role in their regulation, in part through the fine-tuning of IL-4 levels. The spontaneously activated state of these cells likely enables their cytokine production and other functions in the absence of external stimulation. Ontogenetically, the earlier arising γδ T cells are better positioned than αβ T cells to shape the developing repertoire of NAbs. Intriguingly, ligand specificities of NAbs and γδ T cell receptors appear to be overlapping, perhaps allowing γδ cognate help for certain NAb specificities. Via NAbs, γδ T cells could exert a regulatory influence on numerous processes in health and disease.