Dysregulation of Th1, Th2, Th17, and T regulatory cell-related transcription factor signaling in children with autism

The relationship of immune cells with autism spectrum disorder: a bidirectional Mendelian randomization study

BACKGROUND

Observational studies have indicated a correlation between immunological inflammation and the risk of autism spectrum disorder (ASD). However, the causal relationship between immunological inflammation and ASD remains uncertain.

METHODS

Immunity-wide data sources were retrieved from the GWAS catalog. Genetic summary data on ASD were retrieved from two independent GWAS. We performed two independent bi-directional, two-sample Mendelian randomization (MR) analyses and a meta-analysis based on the two independent MR estimates to assess the causal relationship between ASD and immune cell signatures.

RESULTS

We have discovered 26 potential correlations between genetic predisposition in the immunophenotypes and ASD. The meta-analysis of the two inverse variance weighted (IVW)-produced estimates provided further evidence supporting the potential causal relationship between immunophenotypes and ASD. Based on the findings of the reverse MR analysis, it was determined that there are two potential negative causal relationships between ASD and immunophenotypes. However, the meta-analysis of the two IVW-derived MR estimates indicated that immunophenotypes were not significantly influenced by ASD (OR = 0.87, 95% CI = 0.73 -1.03, P = 0.09; OR = 0.91, 95% CI = 0.81-1.01, P = 0.08).

CONCLUSIONS

This study expanded immune cell subtypes that were potentially causally associated with ASD risk as well as identified ASD-specific immune cell subtypes. The discovery has the potential to lead to earlier detection and more effective treatment techniques.

Mesenchymal Stem Cells and Purinergic Signaling in Autism Spectrum Disorder: Bridging the Gap between Cell-Based Strategies and Neuro-Immune Modulation

The prevalence of autism spectrum disorder (ASD) is still increasing, which means that this neurodevelopmental lifelong pathology requires special scientific attention and efforts focused on developing novel therapeutic approaches. It has become increasingly evident that neuroinflammation and dysregulation of neuro-immune cross-talk are specific hallmarks of ASD, offering the possibility to treat these disorders by factors modulating neuro-immunological interactions. Mesenchymal stem cell-based therapy has already been postulated as one of the therapeutic approaches for ASD; however, less is known about the molecular mechanisms of stem cell influence. One of the possibilities, although still underestimated, is the paracrine purinergic activity of MSCs, by which stem cells ameliorate inflammatory reactions. Modulation of adenosine signaling may help restore neurotransmitter balance, reduce neuroinflammation, and improve overall brain function in individuals with ASD. In our review article, we present a novel insight into purinergic signaling, including but not limited to the adenosinergic pathway and its role in neuroinflammation and neuro-immune cross-talk modulation. We anticipate that by achieving a greater understanding of the purinergic signaling contribution to ASD and related disorders, novel therapeutic strategies may be devised for patients with autism in the near future.

Aflatoxin B1 exposure exacerbates chemokine receptor expression in the BTBR T+ Itpr3tf/J Mouse Model, unveiling insights into autism spectrum disorder: A focus on brain and spleen

OBJECTIVE

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by significant difficulties in social interaction, communication, and repeated stereotypic behaviour. Aflatoxin B1 (AFB1) is the most potent and well-known mycotoxin in various food sources. Despite its propensity to generate significant biochemical and structural changes in human and animal tissues, the influence of AFB1 on ASD has yet to be thoroughly studied. Mounting evidence indicates that chemokine receptors play a crucial function in the central nervous system and are implicated in developing several neuroinflammatory disorders. Chemokine receptors in individuals with ASD were elevated in the anterior cingulate gyrus astrocytes, cerebellum, and brain.

METHODS

The BTBR T+Itpr3tf/J (BTBR) mice are inbred strains that exhibit strong and consistently observed deficits in social interactions, characterized by excessive self-grooming and limited vocalization in social contexts. We examined the impact of AFB1 on CCR3-, CCR7-, CCR9-, CXCR3-, CXCR4-, and CXCR6-expressing I-A/I-E+ cells in the spleen of the BTBR mouse model of autism. We evaluated the mRNA levels of CCR3, CCR7, CCR9, CXCR3, CXCR4, and CXCR6 chemokine receptors in the brain.

RESULTS

The exposure to AFB1 in BTBR mice resulted in a significant rise in the number of I-A/I-E+CCR3+, I-A/I-E+CCR7+, I-A/I-E+CCR9+, I-A/I-E+CXCR3+, I-A/I-E+CXCR4+, and I-A/I-E+CXCR6+ cells. Furthermore, exposure to AFB1 increased mRNA expression levels of CCR3, CCR7, CCR9, CXCR3, CXCR4, and CXCR6 in the brain.

CONCLUSIONS

These findings highlight that AFB1 exposure increases the expression of chemokine receptors in BTBR mice, indicating the necessity for further research into AFB1's role in the development of ASD.

Prenatal and postnatal neuroimmune interactions in neurodevelopmental disorders

The intricate relationship between immune dysregulation and neurodevelopmental disorders (NDDs) has been observed across the stages of both prenatal and postnatal development. In this Review, we provide a comprehensive overview of various maternal immune conditions, ranging from infections to chronic inflammatory conditions, that impact the neurodevelopment of the fetus during pregnancy. Furthermore, we examine the presence of immunological phenotypes, such as immune-related markers and coexisting immunological disorders, in individuals with NDDs. By delving into these findings, we shed light on the potential underlying mechanisms responsible for the high occurrence of immune dysregulation alongside NDDs. We also discuss current mouse models of NDDs and their contributions to our understanding of the immune mechanisms underlying these diseases. Additionally, we discuss how neuroimmune interactions contribute to shaping the manifestation of neurological phenotypes in individuals with NDDs while also exploring potential avenues for mitigating these effects.

High-fat diet-induced obesity causes intestinal Th17/Treg imbalance that impairs the intestinal barrier and aggravates anxiety-like behavior in mice

The prevalence of autism spectrum disorders (ASD) has been steadily increasing, and growing evidence suggests a link between high-fat diet (HFD), obesity, and ASD; however, the mechanism underlying this association remains elusive. Herein, BTBR T + tf/J (BTBR) inbred mice (a mouse ASD model) and C57Bl/6J (C57) mice were fed an HFD and normal diet (ND) for 8 weeks (groups: C57 + ND, C57 + HFD, BTBR + ND, and BTBR + HFD). Subsequently, mice underwent behavioral assessments, followed by intestinal tissues harvesting to detect expression of intestinal barrier proteins and inflammatory factors and immune cell numbers, and a correlation analysis. HFD-fed BTBR mice developed obesity, elevated blood sugar, significantly aggravated anxiety-like behaviors, impaired intestinal barrier function, intestinal inflammation with elevated CD4+IL17+ T (Th17) cells and reduced CD4+Foxp3+ T (Treg) cells, exhibiting reduced expression of proteins related to AMPK regulatory pathway (AMPK, p-AMPK, SIRT1). Correlation analysis revealed that the degree of behavioral anxiety, the degree of intestinal barrier damage, the severity of intestinal inflammation, and the degree of immune cell imbalance positively correlated with each other. Accordingly, HFD-induced obesity may cause intestinal Th17/Treg imbalance via the AMPK-SIRT1 pathway, leading to an inflammatory environment in the intestine, impairing intestinal barrier function, and ultimately aggravating anxiety-like behaviors in mice.

Cadmium exposure exacerbates immunological abnormalities in a BTBR T+ Itpr3tf/J autistic mouse model by upregulating inflammatory mediators in CD45R-expressing cells

Autism spectrum disorder (ASD) is a neurodevelopmental illness characterized by behavior, learning, communication, and social interaction abnormalities in various situations. Individuals with impairments usually exhibit restricted and repetitive actions. The actual cause of ASD is yet unknown. It is believed, however, that a mix of genetic and environmental factors may play a role in its development. Certain metals have been linked to the development of neurological diseases, and the prevalence of ASD has shown a positive association with industrialization. Cadmium chloride (Cd) is a neurotoxic chemical linked to cognitive impairment, tremors, and neurodegenerative diseases. The BTBR T+ Itpr3tf/J (BTBR) inbred mice are generally used as a model for ASD and display a range of autistic phenotypes. We looked at how Cd exposure affected the signaling of inflammatory mediators in CD45R-expressing cells in the BTBR mouse model of ASD. In this study, we looked at how Cd affected the expression of numerous markers in the spleen, including IFN-γ, IL-6, NF-κB p65, GM-CSF, iNOS, MCP-1, and Notch1. Furthermore, we investigated the effect of Cd exposure on the expression levels of numerous mRNA molecules in brain tissue, including IFN-γ, IL-6, NF-κB p65, GM-CSF, iNOS, MCP-1, and Notch1. The RT-PCR technique was used for this analysis. Cd exposure increased the number of CD45R+IFN-γ+, CD45R+IL-6+, CD45R+NF-κB p65+, CD45R+GM-CSF+, CD45R+GM-CSF+, CD45R+iNOS+, and CD45R+Notch1+ cells in the spleen of BTBR mice. Cd treatment also enhanced mRNA expression in brain tissue for IFN-γ, IL-6, NF-κB, GM-CSF, iNOS, MCP-1, and Notch1. In general, Cd increases the signaling of inflammatory mediators in BTBR mice. This study is the first to show that Cd exposure causes immune function dysregulation in the BTBR ASD mouse model. As a result, our study supports the role of Cd exposure in the development of ASD.

The Exposure to Lead (Pb) Exacerbates Immunological Abnormalities in BTBR T+ Itpr3tf/J Mice through the Regulation of Signaling Pathways Relevant to T Cells

Autism spectrum disorder (ASD) is a common neurodevelopmental illness characterized by abnormal social interactions, communication difficulties, and repetitive and limited behaviors or interests. The BTBR T+ Itpr3tf/J (BTBR) mice have been used extensively to research the ASD-like phenotype. Lead (Pb) is a hazardous chemical linked to organ damage in the human body. It is regarded as one of the most common metal exposure sources and has been connected to the development of neurological abnormalities. We used flow cytometry to investigate the molecular mechanism behind the effect of Pb exposure on subsets of CD4+ T cells in the spleen expressing IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, AhR, IL-10, and Foxp3. Furthermore, using RT-PCR, we studied the effect of Pb on the expression of numerous genes in brain tissue, including IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, AhR, IL-10, and Foxp3. Pb exposure increased the population of CD4+IFN-γ+, CD4+T-bet+, CD4+STAT1+, CD4+STAT4+, CD4+IL-9+, CD4+IRF4+, CD4+IL-22+, and CD4+AhR+ cells in BTBR mice. In contrast, CD4+IL-10+ and CD4+Foxp3+ cells were downregulated in the spleen cells of Pb-exposed BTBR mice compared to those treated with vehicle. Furthermore, Pb exposure led to a significant increase in IFN-γ, T-bet, STAT1, STAT4, IL-9, IRF4, IL-22, and AhR mRNA expression in BTBR mice. In contrast, IL-10 and Foxp3 mRNA expression was significantly lower in those treated with the vehicle. Our data suggest that Pb exposure exacerbates immunological dysfunctions associated with ASD. These data imply that Pb exposure may increase the risk of ASD.

Aflatoxin B1 Exposure Aggravates Neurobehavioral Deficits and Immune Dysfunctions of Th1, Th9, Th17, Th22, and T Regulatory Cell-Related Transcription Factor Signaling in the BTBR T+Itpr3tf/J Mouse Model of Autism

Autism spectrum disorder (ASD) is a neurodevelopmental disease characterized by impaired communication, reciprocal social interactions, restricted sociability deficits, and stereotyped behavioral patterns. Environmental factors and genetic susceptibility have been implicated in an increased risk of ASD. Aflatoxin B1 (AFB1) is a typical contaminant of food and feed that causes severe immune dysfunction in humans and animals. Nevertheless, the impact of ASD on behavioral and immunological responses has not been thoroughly examined. To investigate this phenomenon, we subjected BTBR T+Itpr3tf/J (BTBR) mice to AFB1 and evaluated their marble-burying and self-grooming behaviors and their sociability. The exposure to AFB1 resulted in a notable escalation in marble-burying and self-grooming activities while concurrently leading to a decline in social contacts. In addition, we investigated the potential molecular mechanisms that underlie the impact of AFB1 on the production of Th1 (IFN-γ, STAT1, and T-bet), Th9 (IL-9 and IRF4), Th17 (IL-17A, IL-21, RORγT, and STAT3), Th22 (IL-22, AhR, and TNF-α), and T regulatory (Treg) (IL-10, TGF-β1, and FoxP3) cells in the spleen. This was achieved using RT-PCR and Western blot analyses to assess mRNA and protein expression in brain tissue. The exposure to AFB1 resulted in a significant upregulation of various immune-related factors, including IFN-γ, STAT1, T-bet, IL-9, IRF4, IL-17A, IL-21, RORγ, STAT3, IL-22, AhR, and TNF-α in BTBR mice. Conversely, the production of IL-10, TGF-β1, and FoxP3 by CD4+ T cells was observed to be downregulated. Exposure to AFB1 demonstrated a notable rise in Th1/Th9/Th22/Th17 levels and a decrease in mRNA and protein expression of Treg. The results above underscore the significance of AFB1 exposure in intensifying neurobehavioral and immunological abnormalities in BTBR mice, hence indicating the necessity for a more comprehensive investigation into the contribution of AFB1 to the development of ASD.

Therapeutic potential of NOX inhibitors in neuropsychiatric disorders

RATIONALE

Neuropsychiatric disorders encompass a broad category of medical conditions that include both neurology as well as psychiatry such as major depressive disorder, autism spectrum disorder, bipolar disorder, schizophrenia as well as psychosis.

OBJECTIVE

NADPH-oxidase (NOX), which is the free radical generator, plays a substantial part in oxidative stress in neuropsychiatric disorders. It is thought that elevated oxidative stress as well as neuroinflammation plays a part in the emergence of neuropsychiatric disorders. Including two linked with membranes and four with subunits of cytosol, NOX is a complex of multiple subunits. NOX has been linked to a significant source of reactive oxygen species in the brain. NOX has been shown to control memory processing and neural signaling. However, excessive NOX production has been linked to cardiovascular disorders, CNS degeneration, and neurotoxicity. The increase in NOX leads to the progression of neuropsychiatric disorders.

RESULT

Our review mainly emphasized the characteristics of NOX and its various mechanisms, the modulation of NOX in various neuropsychiatric disorders, and various studies supporting the fact that NOX might be the potential therapeutic target for neuropsychiatric disorders.

CONCLUSION

Here, we summarizes various pharmacological studies involving NOX inhibitors in neuropsychiatric disorders.

Integrative analysis of γδT cells and dietary factors reveals predictive values for autism spectrum disorder in children

BACKGROUND

Autism spectrum disorder (ASD) includes a range of multifactorial neurodevelopmental disabilities characterized by a variable set of neuropsychiatric symptoms. Immunological abnormalities have been considered to play important roles in the pathogenesis of ASD, but it is still unknown which abnormalities are more prominent.

METHODS

A total of 105 children with ASD and 105 age and gender-matched typically developing (TD) children were recruited. An eating and mealtime behavior questionnaire, dietary habits, and the Bristol Stool Scale were investigated. The immune cell profiles in peripheral blood were analyzed by flow cytometry, and cytokines (IFN-γ, IL-8, IL-10, IL-17A, and TNF-α) in plasma were examined by Luminex assay. The obtained results were further validated using an external validation cohort including 82 children with ASD and 51 TD children.

RESULTS

Compared to TD children, children with ASD had significant eating and mealtime behavioral changes and gastrointestinal symptoms characterized by increased food fussiness and emotional eating, decreased fruit and vegetable consumption, and increased stool astriction. The proportion of γδT cells was significantly higher in children with ASD than TD children (β: 0.156; 95% CI: 0.888 ∼ 2.135, p < 0.001) even after adjusting for gender, eating and mealtime behaviors, and dietary habits. In addition, the increased γδT cells were evident in all age groups (age < 48 months: β: 0.288; 95% CI: 0.420 ∼ 4.899, p = 0.020; age ≥ 48 months: β: 0.458; 95% CI: 0.694 ∼ 9.352, p = 0.024), as well as in boys (β: 0.174; 95% CI: 0.834 ∼ 2.625, p < 0.001) but not in girls. These findings were also confirmed by an external validation cohort. Furthermore, IL-17, but not IFN-γ, secretion by the circulating γδT cells was increased in ASD children. Machine learning revealed that the area under the curve in nomogram plots for increased γδT cells combined with eating behavior/dietary factors was 0.905, which held true in both boys and girls and in all the age groups of ASD children. The decision curves showed that children can receive significantly higher diagnostic benefit within the threshold probability range from 0 to 1.0 in the nomogram model.

CONCLUSIONS

Children with ASD present with divergent eating and mealtime behaviors and dietary habits as well as gastrointestinal symptoms. In peripheral blood, γδT cells but not αβT cells are associated with ASD. The increased γδT cells combined with eating and mealtime behavior/dietary factors have a high value for assisting in the diagnosis of ASD.

Upregulation of Inflammatory Mediators in Peripheral Blood CD40+ Cells in Children with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a common and severe neurodevelopmental disorder in early childhood, defined as social and communication deficits and repetitive and stereotypic behaviours. The aetiology is unknown in most cases. However, several studies have identified immune dysregulation as potentially promoting ASD. Among the numerous immunological findings in ASD, reports of increased pro-inflammatory markers remain the most consistently observed. C-C chemokine receptor type 1 (CCR1) activation is pro-inflammatory in several neurological disorders. Previous evidence has implied that the expression of chemokine receptors, inflammatory mediators, and transcription factors play a pivotal role in several neuroinflammatory disorders. There have also been reports on the association between increased levels of proinflammatory cytokines and ASD. In this study, we aimed to investigate the possible involvement of CCR1, inflammatory mediators, and transcription factor expression in CD40⁺ cells in ASD compared to typically developing controls (TDC). Flow cytometry analysis was used to determine the levels of CCR1-, IFN-γ-, T-box transcription factor (T-bet-), IL-17A-, retinoid-related orphan receptor gamma t (RORγt-), IL-22- and TNF-α-expressing CD40 cells in PBMCs in children with ASD and the TDC group. We further examined the mRNA and protein expression levels of CCR1 using real-time PCR and western blot analysis. Our results revealed that children with ASD had significantly increased numbers of CD40⁺CCR1⁺, CD40⁺IFN-γ⁺, CD40⁺T-bet⁺, CD40⁺IL-17A⁺, CD40⁺RORγt⁺, CD4⁺IL-22⁺, and CD40⁺TNF-α⁺ cells compared with the TDC group. Furthermore, children with ASD had higher CCR1 mRNA and protein expression levels than those in the TDC group. These results indicate that CCR1, inflammatory mediators, and transcription factors expressed in CD40 cells play vital roles in disease progression.

Cadmium Exposure Is Associated with Behavioral Deficits and Neuroimmune Dysfunction in BTBR T+ Itpr3tf/J Mice

Autism spectrum disorders (ASD) are neurobehavioral disabilities characterized by impaired social interactions, poor communication skills, and restrictive/repetitive behaviors. Cadmium is a common heavy metal implicated in ASD. In this study, we investigated the effects of Cd exposure on BTBR T+ Itpr3tf/J (BTBR) mice, an ASD model. We looked for changes in repetitive behaviors and sociability through experiments. We also explored the molecular mechanisms underlying the effects of Cd exposure, focusing on proinflammatory cytokines and pathways. Flow cytometry measured IL-17A-, IL-17F-, IL-21-, TNF-α-, STAT3-, and RORγt-expressing CD4+ T cells from the spleens of experimental mice. We then used RT-PCR to analyze IL-17A, IL-17F, IL-21, TNF-α, STAT3, and RORγ mRNA expression in the brain. The results of behavioral experiments showed that Cd exposure significantly increased self-grooming and marble-burying in BTBR mice while decreasing social interactions. Cd exposure also significantly increased the number of CD4+IL-17A+, CD4+IL-17F+, CD4+IL-21+, CD4+TNF-α+, CD4+STAT3+, and CD4+RORγt+ cells, while upregulating the mRNA expression of the six molecules in the brain. Overall, our results suggest that oral exposure to Cd aggravates behavioral and immune abnormalities in an ASD animal model. These findings have important implications for ASD etiology and provide further evidence of heavy metals contributing to neurodevelopmental disorders through proinflammatory effects.

Oxidative stress and neuroimmune proteins in a mouse model of autism

Oxidative stress including decreased antioxidant enzyme activities, elevated lipid peroxidation, and accumulation of advanced glycation end products in the blood from children with autism spectrum disorders (ASD) has been reported. The mechanisms affecting the development of ASD remain unclear; however, toxic environmental exposures leading to oxidative stress have been proposed to play a significant role. The BTBRT+Itpr3tf/J (BTBR) strain provides a model to investigate the markers of oxidation in a mouse strain exhibiting ASD-like behavioral phenotypes. In the present study, we investigated the level of oxidative stress and its effects on immune cell populations, specifically oxidative stress affecting surface thiols (R-SH), intracellular glutathione (iGSH), and expression of brain biomarkers that may contribute to the development of the ASD-like phenotypes that have been observed and reported in BTBR mice. Lower levels of cell surface R-SH were detected on multiple immune cell subpopulations from blood, spleens, and lymph nodes and for sera R-SH levels of BTBR mice compared to C57BL/6 J (B6) mice. The iGSH levels of immune cell populations were also lower in the BTBR mice. Elevated protein expression of GATA3, TGM2, AhR, EPHX2, TSLP, PTEN, IRE1α, GDF15, and metallothionein in BTBR mice is supportive of an increased level of oxidative stress in BTBR mice and may underpin the pro-inflammatory immune state that has been reported in the BTBR strain. Results of a decreased antioxidant system suggest an important oxidative stress role in the development of the BTBR ASD-like phenotype.

Immunoregulatory and/or Anti-inflammatory Agents for the Management of Core and Associated Symptoms in Individuals with Autism Spectrum Disorder: A Narrative Review of Randomized, Placebo-Controlled Trials

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental condition with a so far poorly understood underlying pathogenesis, and few effective therapies for core symptoms. Accumulating evidence supports an association between ASD and immune/inflammatory processes, arising as a possible pathway for new drug intervention. However, current literature on the efficacy of immunoregulatory/anti-inflammatory interventions on ASD symptoms is still limited. The aim of this narrative review was to summarize and discuss the latest evidence on the use of immunoregulatory and/or anti-inflammatory agents for the management of this condition. During the last 10 years, several randomized, placebo-controlled trials on the effectiveness of (add-on) treatment with prednisolone, pregnenolone, celecoxib, minocycline, N-acetylcysteine (NAC), sulforaphane (SFN), and/or omega-3 fatty acids have been performed. Overall, a beneficial effect of prednisolone, pregnenolone, celecoxib, and/or omega-3 fatty acids on several core symptoms, such as stereotyped behavior, was found. (Add-on) treatment with prednisolone, pregnenolone, celecoxib, minocycline, NAC, SFN, and/or omega-3 fatty acids was also associated with a significantly higher improvement in other symptoms, such as irritability, hyperactivity, and/or lethargy when compared with placebo. The mechanisms by which these agents exert their action and improve symptoms of ASD are not fully understood. Interestingly, studies have suggested that all these agents may suppress microglial/monocyte proinflammatory activation and also restore several immune cell imbalances (e.g., T regulatory/T helper-17 cell imbalances), decreasing the levels of proinflammatory cytokines, such as interleukin (IL)-6 and/or IL-17A, both in the blood and in the brain of individuals with ASD. Although encouraging, the performance of larger randomized placebo-controlled trials, including more homogeneous populations, dosages, and longer periods of follow-up, are urgently needed in order to confirm the findings and to provide stronger evidence.

Effects of amlodipine combined with atorvastatin on Th17/Treg imbalance and vascular microcirculation in hypertensive patients with atherosclerosis: A double-blind, single-center randomized controlled trial

OBJECTIVE

Helper T cells 17 (Th17) and regulatory T cells (Treg), as CD4+T lymphocyte subsets, play an important role in the process of atherosclerosis. However, there are few studies on the regulation and efficacy of atorvastatin combined with amlodipine on Th17/Treg balance in hypertension combined with carotid atherosclerosis. Therefore, this study aims to verify the efficacy and immunomodulatory effects of atorvastatin combined with amlodipine in the treatment of hypertension combined with carotid atherosclerosis.

METHODS

A total of 260 patients with hypertension and carotid atherosclerosis were randomly divided into atorvastatin or combined treatment group. Inflammatory factors and Th17 and Treg levels were detected by enzyme-linked immunosorbent assay and flow cytometry. The messenger ribonucleic acid expression of retinoic acid receptor-related orphan receptor gamma and forkhead spiral transcription factor were detected by real-time quantitative polymerse chain reaction.

RESULTS

We found that the total effective rate in the treatment group was significantly higher than that in the control group. The levels of whole blood high shear viscosity, whole blood low shear viscosity, plasma specific viscosity and fibrin content in the 2 groups were significantly decreased after treatment, and the combined group was significantly lower than the control group (all P < .05). The improvement of endothelial function in the treatment group was also significantly higher than that in the control group (all P < .05). In addition, we found that there were statistically significant differences in Th17 percentage, Treg percentage and Treg/Th17 between the treatment group and the control group (P < .05). The messenger ribonucleic acid levels of retinoic acid receptor-related orphan receptor gamma and forkhead spiral transcription factor showed the same trend. Further detection of Th17-related inflammatory factors showed that the expression of interleukin (IL)-17, IL-6, IL-23 and tumor necrosis factor-α in the treatment group was significantly decreased, which was better than that in the control group (all P < .05).

CONCLUSION

These data indicate that amlodipine combined with atorvastatin can improve Th17/Treg imbalance, vascular endothelial function and efficacy in patients with hypertension and atherosclerosis.

Sex Differences in Neurodevelopmental Disorders: A Key Role for the Immune System

Sex differences are prominent defining features of neurodevelopmental disorders. Understanding the sex biases in these disorders can shed light on mechanisms leading to relative risk and resilience for the disorders, as well as more broadly advance our understanding of how sex differences may relate to brain development. The prevalence of neurodevelopmental disorders is increasing, and the two most common neurodevelopmental disorders, Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) exhibit male-biases in prevalence rates and sex differences in symptomology. While the causes of neurodevelopmental disorders and their sex differences remain to be fully understood, increasing evidence suggests that the immune system plays a critical role in shaping development. In this chapter we discuss sex differences in prevalence and symptomology of ASD and ADHD, review sexual differentiation and immune regulation of neurodevelopment, and discuss findings from human and rodent studies of immune dysregulation and perinatal immune perturbation as they relate to potential mechanisms underlying neurodevelopmental disorders. This chapter will give an overview of how understanding sex differences in neuroimmune function in the context of neurodevelopmental disorders could lend insight into their etiologies and better treatment strategies.

Unique Features of the Immune Response in BTBR Mice

Inflammation plays a considerable role in the pathogenesis of many diseases, including neurodegenerative and psychiatric ones. Elucidation of the specific features of an immune response in various model organisms, and studying the relation of these features with the behavioral phenotype, can improve the understanding of the molecular mechanisms of many psychopathologies. In this work, we focused on BTBR mice, which have a pronounced autism-like behavioral phenotype, elevated levels of oxidative-stress markers, an abnormal immune response, several structural aberrations in the brain, and other unique traits. Although some studies have already shown an abnormal immune response in BTBR mice, the existing literature data are still fragmentary. Here, we used inflammation induced by low-dose lipopolysaccharide, polyinosinic:polycytidylic acid, or their combinations, in mice of strains BTBR T+Itpr3tf/J (BTBR) and C57BL6/J. Peripheral inflammation was assessed by means of a complete blood count, lymphocyte immunophenotyping, and expression levels of cytokines in the spleen. Neuroinflammation was evaluated in the hypothalamus and prefrontal cortex by analysis of mRNA levels of proinflammatory cytokines (tumor necrosis factor, Tnf), (interleukin-1 beta, Il-1β), and (interleukin-6, Il-6) and of markers of microglia activation (allograft inflammatory factor 1, Aif1) and astroglia activation (glial fibrillary acidic protein, Gfap). We found that in both strains of mice, the most severe inflammatory response was caused by the administration of polyinosinic:polycytidylic acid, whereas the combined administration of the two toll-like receptor (TLR) agonists did not enhance this response. Nonetheless, BTBR mice showed a more pronounced response to low-dose lipopolysaccharide, an altered lymphocytosis ratio due to an increase in the number of CD4+ lymphocytes, and high expression of markers of activated microglia (Aif1) and astroglia (Gfap) in various brain regions as compared to C57BL6/J mice. Thus, in addition to research into mechanisms of autism-like behavior, BTBR mice can be used as a model of TLR3/TLR4-induced neuroinflammation and a unique model for finding and evaluating the effectiveness of various TLR antagonists aimed at reducing neuroinflammation.

Systemic maternal inflammation promotes ASD via IL-6 and IFN-γ

Autism spectrum disorder (ASD) is a neurological disorder that manifests during early development, impacting individuals through their ways of communicating, social behaviors, and their ability to perform day-to-day activities. There have been different proposed mechanisms on how ASD precipitates within a patient, one of which being the impact cytokines have on fetal development once a mother's immune system has been activated (referred to as maternal immune activation, MIA). The occurrence of ASD has long been associated with elevated levels of several cytokines, including interleukin-6 (IL-6) and interferon gamma (IFN-γ). These proinflammatory cytokines can achieve high systemic levels in response to immune activating pathogens from various extrinsic sources. Transfer of cytokines such as IL-6 across the placental barrier allows accumulation in the fetus, potentially inducing neuroinflammation and consequently altering neurodevelopmental processes. Individuals who have been later diagnosed with ASD have been observed to have elevated levels of IL-6 and other proinflammatory cytokines during gestation. Moreover, the outcome of MIA has been associated with neurological effects such as impaired social interaction and an increase in repetitive behavior in animal models, supporting a mechanistic link between gestational inflammation and development of ASD-like characteristics. The present review attempts to provide a concise overview of the available preclinical and clinical data that suggest cross-talk between IL-6 and IFN-γ through both extrinsic and intrinsic factors as a central mechanism of MIA that may promote the development of ASD.

Activation of the Monocyte/Macrophage System and Abnormal Blood Levels of Lymphocyte Subpopulations in Individuals with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a so far unknown etiology. Increasing evidence suggests that a state of systemic low-grade inflammation may be involved in the pathophysiology of this condition. However, studies investigating peripheral blood levels of immune cells, and/or of immune cell activation markers such as neopterin are lacking and have provided mixed findings. We performed a systematic review and meta-analysis of studies comparing total and differential white blood cell (WBC) counts, blood levels of lymphocyte subpopulations and of neopterin between individuals with ASD and typically developing (TD) controls (PROSPERO registration number: CRD CRD42019146472). Online searches covered publications from 1 January 1994 until 1 March 2022. Out of 1170 publication records identified, 25 studies were finally included. Random-effects meta-analyses were carried out, and sensitivity analyses were performed to control for potential moderators. Results: Individuals with ASD showed a significantly higher WBC count (k = 10, g = 0.29, p = 0.001, I2 = 34%), significantly higher levels of neutrophils (k = 6, g = 0.29, p = 0.005, I2 = 31%), monocytes (k = 11, g = 0.35, p < 0.001, I2 = 54%), NK cells (k = 7, g = 0.36, p = 0.037, I2 = 67%), Tc cells (k = 4, g = 0.73, p = 0.021, I2 = 82%), and a significantly lower Th/Tc cells ratio (k = 3, g = −0.42, p = 0.008, I2 = 0%), compared to TD controls. Subjects with ASD were also characterized by a significantly higher neutrophil-to-lymphocyte ratio (NLR) (k = 4, g = 0.69, p = 0.040, I2 = 90%), and significantly higher neopterin levels (k = 3, g = 1.16, p = 0.001, I2 = 97%) compared to TD controls. No significant differences were found with respect to the levels of lymphocytes, B cells, Th cells, Treg cells, and Th17 cells. Sensitivity analysis suggested that the findings for monocyte and neutrophil levels were robust, and independent of other factors, such as medication status, diagnostic criteria applied, and/or the difference in age or sex between subjects with ASD and TD controls. Taken together, our findings suggest the existence of a chronically (and systemically) activated inflammatory response system in, at least, a subgroup of individuals with ASD. This might have not only diagnostic, but also, therapeutic implications. However, larger longitudinal studies including more homogeneous samples and laboratory assessment methods and recording potential confounding factors such as body mass index, or the presence of comorbid psychiatric and/or medical conditions are urgently needed to confirm the findings.

Impairment in the Intestinal Morphology and in the Immunopositivity of Toll-like Receptor-4 and Other Proteins in an Autistic Mouse Model

Autism spectrum disorder (ASD) identifies a neurodevelopmental disease defined by social impairments and repetitive or stereotyped behaviors. The etiology of ASD remains unclear; it primarily affects the brain, but a link between gastrointestinal (GI) diseases, inflammatory mucosal pathology and this disorder has been suggested. In particular, a central role seems to be played by an imbalance in pro-and anti-inflammatory cytokines, oxidative stress, and apoptosis. Toll-like receptor 4 (TLR4) is a protein of innate immunity responsible for the regulation and maintenance of intestinal homeostasis. Through histochemical and immunohistochemical evaluations we analyzed the intestinal morphology and the immunopositivity of TLR4 and of other pro-inflammatory and apoptotic proteins in BTBR T+Itpr3tf/J mice. Morphological data showed that the mucosal tunica presented longer intestinal villi. The length of the villi and the epithelial surface determine the exchanges of the intestinal mucosa with luminal contents, modifying the microbiota composition. The biochemical and immunohistochemical results indicated a close relationship among the increase of TLR4 and the activation of NF-kB subunits (p65 and p50) and pro-inflammatory and apoptotic proteins, such as cyclooxygenase-2, interleukin-1β, inducible nitric oxide synthase, tumor nuclear factor—alpha, caspase-3, caspase-8. These preliminary results require more in-depth study but they suggest the TLR4 signaling pathway as a possible target for therapeutic approaches to reduce GI disorders in ASD.

CCR1 antagonist J-113863 corrects the imbalance of pro- and anti-inflammatory cytokines in a SJL/J mouse model of relapsing-remitting multiple sclerosis

Multiple sclerosis (MS), an immune-mediated and neurodegenerative disorder of the central nervous system (CNS), is characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model used to study MS. To explore the impact of chemokine receptor CCR1 blockade in EAE and the underlying mechanisms, we used CCR1 antagonist J-113863 in PLP_139-151-induced EAE in SJL/J mice. Following EAE induction, mice were treated with J-113863 (10 mg/kg) daily from day 14 until day 25. We investigated the effect of J-113863 on expression levels of GM-CSF, IL-6, IL-10, IL-27 in CD4⁺ spleen cells, using flow cytometry. We also analyzed the effect of J-113863 on GM-CSF, IL-6, IL-10, IL-27 mRNA and protein expression levels using RT-PCR and Western blot analysis in brain tissues. J-113863 treatment decreased the populations of CD4⁺GM-CSF⁺ and CD4⁺IL-6⁺ cells and increased CD4⁺IL-27⁺ and CD4⁺IL-10⁺ cells in the spleen. J-113863 had a suppressive effect on the mRNA and protein expression levels of GM-CSF, and IL-6 in the brain tissue. On the other hand, J-113863 treatment increased the mRNA and protein expression of IL-10 and IL-27 in the brain tissue. Our results highlighted J-113863's potential role in suppressing pro-inflammatory expression and up-regulating anti-inflammatory mediators, which could represent a beneficial alternative approach to MS treatment.

Emerging Roles of T Helper Cells in Non-Infectious Neuroinflammation: Savior or Sinner

CD4⁺ T cells, also known as T helper (Th) cells, contribute to the adaptive immunity both in the periphery and in the central nervous system (CNS). At least seven subsets of Th cells along with their signature cytokines have been identified nowadays. Neuroinflammation denotes the brain’s immune response to inflammatory conditions. In recent years, various CNS disorders have been related to the dysregulation of adaptive immunity, especially the process concerning Th cells and their cytokines. However, as the functions of Th cells are being discovered, it’s also found that their roles in different neuroinflammatory conditions, or even the participation of a specific Th subset in one CNS disorder may differ, and sometimes contrast. Based on those recent and contradictory evidence, the conflicting roles of Th cells in multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, epilepsy, traumatic brain injury as well as some typical mental disorders will be reviewed herein. Research progress, limitations and novel approaches concerning different neuroinflammatory conditions will also be mentioned and compared.

Lead (Pb) exposure exacerbates behavioral and immune abnormalities by upregulating Th17 and NF-κB-related signaling in BTBR T+ Itpr3tf/J autistic mouse model

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder that are characterized by abnormal social interaction impairments in communication and repetitive and restricted activities or interests. Even though the exact etiology of ASD remains unknown. Lead (Pb) is a toxin known to harm many organs in the body, it is one of the most ubiquitous metal exposures which is associated with neurological deficits. Previous studies have shown that the exposure to Pb may play a role in ASD. BTBR T⁺ Itpr3^tf/J (BTBR) mouse model is commonly used as a preclinical model for ASD. In this study, we investigated the effects of Pb exposure on sociability, self-grooming and marble burying behaviors tests in BTBR mice. We further examined the effects of Pb on IL-17A- RORγT-, STAT3-, NF-κB p65-, iNOS-, TLR-2- and TLR-4-producing CD45⁺ cells in spleen using flow cytometry. We also explored the effects of Pb on IL-17A, RORγT, STAT3, NF-κB p65, and TLR-2 mRNA expression in the brain tissue using RT-PCR analysis. Our results demonstrated that Pb exposure substantially increased repetitive behavior, marble burying and decrease social interactions in BTBR mice. In addition, in spleen cells, Pb exposure exaggerated CD45⁺IL-17A⁺, CD45⁺RORγT⁺, CD45⁺STAT3⁺, CD45⁺NF-κB p65⁺, CD45⁺iNOS⁺, CD45⁺TLR-2⁺ and CD45⁺TLR-4⁺ in BTBR mice. We also found that Pb significantly increased IL-17A, RORγT, STAT3, NF-κB p65, and TLR-2 mRNA in the brain tissue. Therefore, Pb exposure exacerbates behavioral and neuroimmune function in BTBR mice, suggesting a potentially strong role for Pb in ASD.

JUN and PDGFRA as Crucial Candidate Genes for Childhood Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder, characterized by marked genetic heterogeneity. In this study, two independent microarray datasets of cerebellum of ASD were integrative analyzed by NetworkAnalyst to screen candidate crucial genes. NetworkAnalyst identified two up-regulated genes, Jun proto-oncogene (JUN) and platelet derived growth factor receptor alpha (PDGFRA), as the most crucial genes in cerebellum of ASD patients. Based on KEGG pathway database, genes associated with JUN in the cerebellum highlight the pathways of Th17 cell differentiation and Th1 and Th2 cell differentiation. Genes associated with PDGFRA in the cerebellum were found enriched in pathways in EGFR tyrosine kinase inhibitor resistance and Rap1 signaling pathway. Analyzing all differentially expressed genes (DEGs) from the two datasets, Gene Set Enrichment Analysis (GSEA) brought out IL17 signaling pathway, which is related to the expression of JUN and PDGFRA. The ImmuCellAI found the elevated expression of JUN and PDGFRA correlating with increased Th17 and monocytes suggests JUN and PDGFRA may regulate Th17 cell activation and monocytes infiltrating. Mice model of maternal immune activation demonstrated that JUN and PDGFRA are up-regulated and related to the ASD-like behaviors that provide insights into the molecular mechanisms underlying the altered IL17 signaling pathway in ASD and may enable novel therapeutic strategies.

Therapeutic Effects of a Novel Form of Biotin on Propionic Acid-Induced Autistic Features in Rats

Magnesium biotinate (MgB) is a novel biotin complex with superior absorption and anti-inflammatory effects in the brain than D-Biotin. This study aimed to investigate the impact of different doses of MgB on social behavior deficits, learning and memory alteration, and inflammatory markers in propionic acid (PPA)-exposed rats. In this case, 35 Wistar rats (3 weeks old) were distributed into five groups: 1, Control; 2, PPA treated group; 3, PPA+MgBI (10 mg, HED); 4, PPA+MgBII (100 mg, HED); 5, PPA+MgBIII (500 mg, HED). PPA was given subcutaneously at 500 mg/kg/day for five days, followed by MgB for two weeks. PPA-exposed rats showed poor sociability and a high level of anxiety-like behaviors and cognitive impairments (p < 0.001). In a dose-dependent manner, behavioral and learning-memory disorders were significantly improved by MgB supplementation (p < 0.05). PPA decreased both the numbers and the sizes of Purkinje cells in the cerebellum. However, MgB administration increased the sizes and the densities of Purkinje cells. MgB improved the brain and serum Mg, biotin, serotonin, and dopamine concentrations, as well as antioxidant enzymes (CAT, SOD, GPx, and GSH) (p < 0.05). In addition, MgB treatment significantly regulated the neurotoxicity-related cytokines and neurotransmission-related markers. For instance, MgB significantly decreased the expression level of TNF-α, IL-6, IL-17, CCL-3, CCL-5, and CXCL-16 in the brain, compared to the control group (p < 0.05). These data demonstrate that MgB may ameliorate dysfunctions in social behavior, learning and memory and reduce the oxidative stress and inflammation indexes of the brain in a rat model.

The role of probiotics in children with autism spectrum disorders: A study protocol for a randomised controlled trial

Background

Autism spectrum disorder (ASD) is a neurological and developmental condition that begins in infancy or earlier and lasts through the individual’s lifetime. The aetiology and mechanisms of ASD are not yet fully understood, and current treatment comprises mainly education and rehabilitation, without significant improvement in the core symptoms. Recent studies suggest that microbiota change in children with ASD after the ingestion of probiotics may improve the balance of microbiota and thus ASD symptoms.

Objective

The objectives of this study are to evaluate the efficacy of probiotics on the symptoms of children with ASD and the possible mechanisms involved.

Methods

This is a prospective controlled trial. A total of 160 children with ASD will be stratified and allocated to placebo and probiotics groups randomised according to the severity of their ASD symptoms. The probiotics group will be given probiotics supplements orally twice a day for 3 months and the control group will be given a placebo at the same amount, in addition to the baseline therapy of education and rehabilitation. All the children will be evaluated systematically by using different scales, questionnaires before, during, and after 3 months’ treatment, as well as 3 months after discontinuation. The potential impact of probiotics on immunity and inflammation, metabolism, and metagenome will also be investigated.

Discussion

Our previous study showed that the abundance of intestinal flora was greatly different in children with ASD, and that Bifidobacterium was associated with the severity of ASD. In the present study, we will investigate the impact of probiotics supplementation on the symptoms of Children with ASD, with the purpose of evaluating the possible therapeutic effects of additives on ASD and of providing a reference for clinical treatment. The results will help to disclose as yet unknown relationship between probiotics and ASD.

Trial registration

This study has been registered with Chinese Clinical Trial Registry (ChiCTR-2000037941).

Maternal Immune Activation and Interleukin 17A in the Pathogenesis of Autistic Spectrum Disorder and Why It Matters in the COVID-19 Era

Autism spectrum disorder (ASD) is the commonest neurodevelopmental disability. It is a highly complex disorder with an increasing prevalence and an unclear etiology. Consensus indicates that ASD arises as a genetically modulated, and environmentally influenced condition. Although pathogenic rare genetic variants are detected in around 20% of cases of ASD, no single factor is responsible for the vast majority of ASD cases or that explains their characteristic clinical heterogeneity. However, a growing body of evidence suggests that ASD susceptibility involves an interplay between genetic factors and environmental exposures. One such environmental exposure which has received significant attention in this regard is maternal immune activation (MIA) resulting from bacterial or viral infection during pregnancy. Reproducible rodent models of ASD are well-established whereby induction of MIA in pregnant dams, leads to offspring displaying neuroanatomical, functional, and behavioral changes analogous to those seen in ASD. Blockade of specific inflammatory cytokines such as interleukin-17A during gestation remediates many of these observed behavioral effects, suggesting a causative or contributory role. Here, we review the growing body of animal and human-based evidence indicating that interleukin-17A may mediate the observed effects of MIA on neurodevelopmental outcomes in the offspring. This is particularly important given the current corona virus disease-2019 (COVID-19) pandemic as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy is a potent stimulator of the maternal immune response, however the long-term effects of maternal SARS-CoV-2 infection on neurodevelopmental outcomes is unclear. This underscores the importance of monitoring neurodevelopmental outcomes in children exposed to SARS-CoV-2-induced MIA during gestation.

FOXP2 down expression is associated with executive dysfunctions and electrophysiological abnormalities of brain in Autism spectrum disorder; a neuroimaging genetic study

BACKGROUND AND AIMS

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by language impairment, and challenges with social interaction, communication, and repetitive behaviors. Although genetics are a primary cause of ASD, the exact genes and molecular mechanisms involved in its pathogenesis are not completely clear. The FOXP2 gene encodes a transcription factor that is known for its major role in language development and severe speech problems. The present study aimed to evaluate the role of FOXP2 in ASD etiology, executive functions, and brain activities.

METHODS

In the present study, we recruited 450 children with ASD and 490 neurotypical control children. Three domains of executive functions (working memory, response inhibition, and vigilance) were assessed. In addition, five-minute eyes closed electroencephalography was obtained from some of the children with ASD and neurotypical children. DNA sequence and expression level of FOXP2 in blood samples of children with ASD and the control group were evaluated by using sequencing and Real-time PCR, respectively.

RESULTS

The results showed no mutations but a significant down expression of FOXP2 genes in children with ASD vs. neurotypical children. Several cognitive and executive function deficiencies were detected in children with ASD. Low alpha and gamma bands in the frontal lobe and high theta bands in the occipital lobe were revealed in children with ASD. We also found several correlations between FOXP2 expression levels and clinical assessments.

CONCLUSIONS

Our finding revealed the down expression of FOXP2, which could be considered as a biomarker for ASD as well as cognitive and executive dysfunction. Based on brain mapping data, FOXP2 may be related to the theta wave abnormality of children with ASD. FOXP2 may be considered a target of novel treatment to improve memory and executive functions.

IMPLICATIONS

Our findings highlight the role of FOXP2 mRNA level in ASD etiology, executive functions, and brain wave frequencies.

Imbalance in pro-inflammatory and anti-inflammatory cytokines milieu in B cells of children with autism

B cells play multiple roles in preservation of healthy immune system including management of immune responses by expression of pro- and anti-inflammatory cytokines. Several earlier studies have documented that B cells express both pro-inflammatory cytokines such as IL-6, TNF-α as well as anti-inflammatory cytokines such as IL-10. However, it is yet to be examined whether these pro-/anti-inflammatory cytokines are expressed in B cells of children with autism spectrum disorder (ASD). Pathophysiology of ASD begins in early childhood and is characterized by repetitive/restricted behavioral patterns, and dysfunction in communal/communication skills. ASD pathophysiology also has a strong component of immune dysfunction which has been highlighted in numerous earlier publications. In this study, we specifically explored pro-/anti-inflammatory cytokines (IL-6, IL-17A, IFN-γ, TNF-α, IL-10) in B cells of ASD subjects and compared them typically developing control (TDC) children. Present study shows that inflammatory cytokines such as IL-6 and TNF-α are elevated in B cells of ASD subjects, while anti-inflammatory cytokine, IL-10 is decreased in ASD group when compared to TDC group. Further, TLR4 activation by its ligand, lipopolysaccharide (LPS) further upregulates inflammatory potential of B cells from ASD group by increasing IL-6 expression, whereas LPS has no significant effect on IL-10 expression in ASD group. Furthermore, LPS-induced inflammatory signaling of IL-6 in B cells of ASD subjects was partially mitigated by the pretreatment with NF-kB inhibitor. Present study propounds the idea that B cells could be crucial players in causing immune dysfunction in ASD subjects through an imbalance in expression of pro-/anti-inflammatory cytokines.

B and T Immunoregulation: A New Insight of B Regulatory Lymphocytes in Autism Spectrum Disorder

Introduction: Autism Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental disorder characterized by a complex pathogenesis, by impairment social communication and interaction, and may also manifest repetitive patterns of behavior. Many studies have recognized an alteration of the immune response as a major etiological component in ASDs. Despite this, it is still unclear the variation of the function of the immune response.

Aim: Our aim is to investigate the levels of immunological markers in peripheral blood of children with ASD such as: regulatory B and T cells, memory B and natural killer (NK) cells.

Materials and Methods: We assessed various subsets of immune cells in peripheral blood (regulatory B and T cells, B-cell memory and natural killer cells) by multi-parametric flow cytometric analysis in 26 ASD children compared to 16 healthy controls (HCs) who matched age and gender.

Results: No significant difference was observed between B-cell memory and NK cells in ASDs and HCs. Instead, regulatory B cells and T cells were decreased (p < 0.05) in ASD subjects when compared to HCs.

Discussion: Regulatory B and T cells have a strategic role in maintaining the immune homeostasis. Their functions have been associated with the development of multiple pathologies especially in autoimmune diseases. According to our study, the immunological imbalance of regulatory B and T cells may play a pivotal role in the evolution of the disease, as immune deficiencies could be related to the severity of the ongoing disorder.

Regulatory T lymphocytes/Th17 lymphocytes imbalance in autism spectrum disorders: evidence from a meta-analysis

Background

Immune system dysfunction has been proposed to play a critical role in the pathophysiology of autism spectrum disorders (ASD). Conflicting reports of lymphocyte subpopulation abnormalities have been described in numerous studies of patients with ASD. To better define lymphocytes abnormalities in ASD, we performed a meta-analysis of the lymphocyte profiles from subjects with ASD.

Methods

We used the PRISMA recommendations to query PubMed, Embase, PsychoINFO, BIOSIS, Science Direct, Cochrane CENTRAL, and Clinicaltrials.gov for terms related to clinical diagnosis of ASD and to lymphocytes’ populations. We selected studies exploring lymphocyte subpopulations in children with ASD. The search protocol has been registered in the international Prospective Register of Systematic Reviews (CRD42019121473).

Results

We selected 13 studies gathering 388 ASD patients and 326 healthy controls. A significant decrease in the CD4+ lymphocyte was found in ASD patients compared to controls [− 1.51 (95% CI − 2.99; − 0.04) p = 0.04] (I² = 96% [95% CI 94.6, 97.7], p < 0.01). No significant difference was found for the CD8+ T, B and natural killer lymphocytes. Considering the CD4+ subpopulation, there was a significant decrease in regulatory T lymphocytes (Tregs) in ASD patients (n = 114) compared to controls (n = 107) [− 3.09 (95% CI − 4.41; − 1.76) p = 0.0001]; (I² = 90.9%, [95% CI 76.2, 96.5], p < 0.0001) associated with an increase oin the Th17 lymphocytes (ASD; n = 147 controls; n = 128) [2.23 (95% CI 0.79; 3.66) p = 0,002] (I² = 95.1% [95% CI 90.4, 97.5], p < 0.0001).

Limitations

Several factors inducing heterogeneity should be considered. First, differences in the staining method may be responsible for a part in the heterogeneity of results. Second, ASD population is also by itself heterogeneous, underlying the need of studying sub-groups that are more homogeneous.

Conclusion

Our meta-analysis indicates defects in CD4+ lymphocytes, specifically decrease oin Tregs and increase in Th17 in ASD patients and supports the development of targeted immunotherapies in the field of ASD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13229-021-00472-4.

Kefir ameliorates specific microbiota-gut-brain axis impairments in a mouse model relevant to autism spectrum disorder

Autism spectrum disorder (ASD) is one of the most severe developmental disorders, affecting on average 1 in 150 children worldwide. There is a great need for more effective strategies to improve quality of life in ASD subjects. The gut microbiome has emerged as a potential therapeutic target in ASD. A novel modulator of the gut microbiome, the traditionally fermented milk drink kefir, has recently been shown to modulate the microbiota and decrease repetitive behaviour, one of the hallmarks of ASD, in mice. As such, we hypothesized that kefir could ameliorate behavioural deficits in a mouse model relevant to ASD; the BTBR T⁺ Itpr3^tf/J mouse strain. To this end, adult mice were administered either kefir (UK4) or a milk control for three weeks as treatment lead-in, after which they were assessed for their behavioural phenotype using a battery of tests. In addition, we assessed systemic immunity by flow cytometry and the gut microbiome using shotgun metagenomic sequencing. We found that indeed kefir decreased repetitive behaviour in this mouse model. Furthermore, kefir prolonged stress-induced increases in corticosterone 60 min post-stress, which was accompanied by an ameliorated innate immune response as measured by LY6C^hi monocyte levels. In addition, kefir increased the levels of anti-inflammatory Treg cells in mesenteric lymph nodes (MLNs). Kefir also increased the relative abundance of Lachnospiraceae bacterium A2, which correlated with reduced repetitive behaviour and increased Treg cells in MLNs. Functionally, kefir modulated various predicted gut microbial pathways, including the gut-brain module S-Adenosylmethionine (SAM) synthesis, as well as L-valine biosynthesis and pyruvate fermentation to isobutanol, which all correlated with repetitive behaviour. Taken together our data show that kefir modulates peripheral immunoregulation, can ameliorate specific ASD behavioural dysfunctions and modulates selective aspects of the composition and function of the gut microbiome, indicating that kefir supplementation might prove a viable strategy in improving quality of life in ASD subjects.

Molecular Mechanisms of Aberrant Neuroplasticity in Autism Spectrum Disorders (Review)

This review presents the analysis and systematization of modern data on the molecular mechanisms of autism spectrum disorders (ASD) development. Polyetiology and the multifactorial nature of ASD have been proved. The attempt has been made to jointly review and systematize current hypotheses of ASD pathogenesis at the molecular level from the standpoint of aberrant brain plasticity. The mechanism of glutamate excitotoxicity formation, the effect of imbalance of neuroactive amino acids and their derivatives, neurotransmitters, and hormones on the ASD formation have been considered in detail. The strengths and weaknesses of the proposed hypotheses have been analyzed from the standpoint of evidence-based medicine. The conclusion has been drawn on the leading role of glutamate excitotoxicity as a biochemical mechanism of aberrant neuroplasticity accompanied by oxidative stress and mitochondrial dysfunction. The mechanism of aberrant neuroplasticity has also been traced at the critical moments of the nervous system development taking into account the influence of various factors of the internal and external environment. New approaches to searching for ASD molecular markers have been considered.

Transcription factors in neurodevelopmental and associated psychiatric disorders: A potential convergence for genetic and environmental risk factors

Neurodevelopmental disorders (NDDs) are a heterogeneous and highly prevalent group of psychiatric conditions marked by impairments in the nervous system. Their onset occurs during gestation, and the alterations are observed throughout the postnatal life. Although many genetic and environmental risk factors have been described in this context, the interactions between them challenge the understanding of the pathways associated with NDDs. Transcription factors (TFs)-a group of over 1,600 proteins that can interact with DNA, regulating gene expression through modulation of RNA synthesis-represent a point of convergence for different risk factors. In addition, TFs organize critical processes like angiogenesis, blood-brain barrier formation, myelination, neuronal migration, immune activation, and many others in a time and location-dependent way. In this review, we summarize important TF alterations in NDD and associated disorders, along with specific impairments observed in animal models, and, finally, establish hypotheses to explain how these proteins may be critical mediators in the context of genome-environment interactions.

Systems Pharmacology Approach and Experiment Evaluation Reveal Multidimensional Treatment Strategy of LiangXueJieDu Formula for Psoriasis

Clinical studies have demonstrated the anti-psoriatic effect of the LiangXueJieDu (LXJD) herbal formula. However, the systemic mechanism and the targets of the LXJD formula have not yet been elucidated. In the present study, a systems pharmacology approach, metabolomics, and experimental evaluation were employed. First, by systematic absorption-distribution-metabolism-excretion (ADME) analysis, 144 active compounds with satisfactory pharmacokinetic properties were identified from 12 herbs of LXJD formula using the TCMSP database. These active compounds could be linked to 125 target proteins involved in the pathological processes underlying psoriasis. Then, the networks constituting the active compounds, targets, and diseases were constructed to decipher the pharmacological actions of this formula, indicating its curative effects in psoriasis treatment and related complications. The psoriasis-related pathway comprising several regulatory modules demonstrated the synergistic mechanisms of LXJD formula. Furthermore, the therapeutic effect of LXJD formula was validated in a psoriasis-like mouse model. Consistent with the systems pharmacology analysis, LXJD formula ameliorated IMQ-induced psoriasis-like lesions in mice, inhibited keratinocyte proliferation, improved keratinocyte differentiation, and suppressed the infiltration of CD3+ T cells. Compared to the model group, LXJD formula treatment remarkably reduced the expression of inflammatory cytokines and factors, such as IL-1β, IL-6, TNF-α, Cox2, and inhibited the phosphorylation of p-P65, p-IқB, p-ERK, p-P38, p-PI3K, p-AKT, indicating that LXJD formula exerts its therapeutic effect by inhibiting the MAPK, PI3K/AKT, and NF-қB signaling pathways. The metabolic changes in the serum of psoriasis patients were evaluated by liquid chromatography coupled with orbitrap mass spectrometry (LC-MS). The LXJD formula improved two perturbed metabolic pathways of glycerophospholipid metabolism and steroid hormone biosynthesis. Overall, this study revealed the complicated anti-psoriatic mechanism of LXJD formula and also offered a reliable strategy to elucidate the complex therapeutic mechanism of this Chinese herbal formula in psoriasis from a holistic perspective.

CXCR3 alleviates renal ischemia‑reperfusion injury via increase of Tregs

Increasing evidence has demonstrated that regulatory T cells (Tregs) suppress innate immunity, as well as protect the kidneys from ischemia‑reperfusion injury (IRI) and offer a potentially effective strategy to prevent or alleviate renal IRI. The present study explored whether C‑X‑C motif chemokine receptor 3 (CXCR3) alleviated renal IRI by increasing Tregs. Male C57BL/6J mice were divided into sham‑surgery, IRI, CXCR3 overexpression (OE‑CXCR3)+IRI, PC61+IRI and OE‑CXCR3+PC61+IRI groups. Histopathological examination of the kidney was carried out using hematoxylin‑eosin and Masson staining. The levels of serum creatinine (Scr) and blood urea nitrogen (BUN) were measured. Blood and kidney levels of IL‑6, TNF‑α, C‑C motif chemokine ligand (CCL)‑2 and IL‑10 were detected by ELISA and western blotting. The levels of superoxide dismutase (SOD), glutathione peroxidase (GSH‑Px) and malondialdehyde (MDA) in kidney tissues were also measured to assess oxidative stress. The population of Tregs in the kidney was assessed using flow cytometry. The results demonstrated that administration of OE‑CXCR3 to IRI mice significantly decreased the levels of Scr, BUN, IL‑6, TNF‑α, CCL‑2 and MDA, increased the levels of IL‑10, SOD and GSH‑Px, and mitigated the morphologic injury and fibrosis induced by IR compared with the IRI group. In addition, administration of OE‑CXCR3 induced significant reductions in the expression levels of fibrosis‑related markers, including fibronectin and type IV collagen, and increased the number of Tregs. These roles of OE‑CXCR3 were significantly neutralized following deletion of Tregs with PC61 (anti‑CD25 antibody). Together, the present study demonstrated that injection of OE‑CXCR3 lentiviral vectors into animal models can alleviate renal IRI by increasing the number of Tregs. The results may be a promising approach for the treatment of renal IRI.

Rescue of maternal immune activation-induced behavioral abnormalities in adult mouse offspring by pathogen-activated maternal Treg cells

Maternal immune activation (MIA) induced by lipopolysaccharides or polyinosinic:polycytidylic acid injections can induce behavioral abnormalities in adult mouse offspring. Here, we used the soluble tachyzoite antigen from Toxoplasma gondii, a parasite that infects approximately two billion people, to induce MIA in mice. The adult male offspring showed autism-relevant behaviors and abnormal brain microstructure, along with a pro-inflammatory T-cell immune profile in the periphery and upregulation of interleukin-6 in brain astrocytes. We show that adoptive transfer of regulatory T (T_reg) cells largely reversed these MIA-induced phenotypes. Notably, pathogen-activated maternal T_reg cells showed greater rescue efficacy than those from control donors. Single-cell RNA sequencing identified and characterized a unique group of pathogen-activated T_reg cells that constitute 32.6% of the pathogen-activated maternal T_reg population. Our study establishes a new preclinical parasite-mimicking MIA model and suggests therapeutic potential of adoptive T_reg cell transfer in neuropsychiatric disorders associated with immune alterations.

Autism Spectrum Disorder: Signaling Pathways and Prospective Therapeutic Targets

The Autism Spectrum Disorder (ASD) consists of a prevalent and heterogeneous group of neurodevelopmental diseases representing a severe burden to affected individuals and their caretakers. Despite substantial improvement towards understanding of ASD etiology and pathogenesis, as well as increased social awareness and more intensive research, no effective drugs have been successfully developed to resolve the main and most cumbersome ASD symptoms. Hence, finding better treatments, which may act as "disease-modifying" agents, and novel biomarkers for earlier ASD diagnosis and disease stage determination are needed. Diverse mutations of core components and consequent malfunctions of several cell signaling pathways have already been found in ASD by a series of experimental platforms, including genetic associations analyses and studies utilizing pre-clinical animal models and patient samples. These signaling cascades govern a broad range of neurological features such as neuronal development, neurotransmission, metabolism, and homeostasis, as well as immune regulation and inflammation. Here, we review the current knowledge on signaling pathways which are commonly disrupted in ASD and autism-related conditions. As such, we further propose ways to translate these findings into the development of genetic and biochemical clinical tests for early autism detection. Moreover, we highlight some putative druggable targets along these pathways, which, upon further research efforts, may evolve into novel therapeutic interventions for certain ASD conditions. Lastly, we also refer to the crosstalk among these major signaling cascades as well as their putative implications in therapeutics. Based on this collective information, we believe that a timely and accurate modulation of these prominent pathways may shape the neurodevelopment and neuro-immune regulation of homeostatic patterns and, hopefully, rescue some (if not all) ASD phenotypes.

5-Aminoisoquinolinone, a PARP-1 Inhibitor, Ameliorates Immune Abnormalities through Upregulation of Anti-Inflammatory and Downregulation of Inflammatory Parameters in T Cells of BTBR Mouse Model of Autism

Autism spectrum disorder (ASD) covers a range of neurodevelopmental disorders involving impairments in communication and repetitive and stereotyped patterns of behavior and reciprocal social interaction. 5-Aminoisoquinolinone (5-AIQ), a PARP-1 inhibitor, has neuroprotective and anti-inflammatory effects. We investigated the influence of 5-AIQ-treatment in BTBR T+ Itpr3tf/J (BTBR) mice as an autism model and used flow cytometry to assess the effect of 5-AIQ on FOXP3, Helios, GATA3, IL-9, IL-10 and IL-17A production by CXCR6+ and CD4+ T cells in the spleen. We also confirmed the effect of 5-AIQ treatment on expression of FOXP3, Helios, GATA3, IL-17A, IL-10, and IL-9 mRNA and protein expression levels in the brain tissue by quantitative PCR and western blotting. Our results demonstrated that 5-AIQ-treated BTBR mice had significantly increased numbers of CXCR6+FOXP3+, CXCR6+IL-10+, and CXCR6+Helios+ cells and decreased numbers of CD4+GATA3+, CD4+IL-9+, and CD4+IL-17A+ cells as compared with those in untreated BTBR mice. Our results further demonstrated that treatment with 5-AIQ in BTBR mice increased expression for FOXP3, IL-10, and Helios, and decreased expression for GATA3, IL-17A, and IL-9 mRNA. Our findings support the hypotheses that 5-AIQ has promising novel therapeutic effects on neuroimmune dysfunction in autism and is associated with modulation of Treg and Th17 cells.

Dysregulation of Ki-67 Expression in T Cells of Children with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by behavioral abnormalities such as impairments in social function and deficits in communication. The etiology of autism is unknown in most cases, but many studies have pointed towards the immune system as a causative agent in autism. Specific studies implicated lymphocytes, natural killer (NK) cells, monocytes, cytokines, and specific transcription factors in the development of ASD. The protein Ki-67 is n expressed in the proliferating cells and is used as a tool in several disorders. Ki-67 plays a crucial role in many neurological diseases. However, Ki-67 role in ASD is not fully understood. In this study, we investigated the possible role of Ki-67 expression in autistic children. We compared Ki-67 production in CD3+, CD4+, CD8+, CXCR4+, CXCR7+, CD45R+, HLA-DR+, GATA3+, Helios+, and FOXP3+ peripheral blood mononuclear cells (PBMCs) in autistic children to typically developing (TD) controls using immunofluorescence staining. We also determined Ki-67 mRNA levels in PBMCs using RT–PCR. The results revealed that autistic children had significantly increased numbers of CD3+Ki-67+, CD4+Ki-67+, CD8+Ki-67+, CXCR4+Ki-67+, CXCR7+Ki-67+, CD45R+Ki-67+, HLA-DR+Ki-67+, CXCR4+GATA3+, GATA3+Ki-67+ cells and decreased Helios+Ki-67+ and FOXP3+Ki-67+ cells compared with TD controls. In addition, the autistic children showed upregulation of Ki-67 mRNA levels compared with TD controls. Further studies need to be carried out to assess the exact role of Ki-67 and its therapeutic potential in ASD.

The Relationship between Autism and Ehlers-Danlos Syndromes/Hypermobility Spectrum Disorders

Considerable interest has arisen concerning the relationship between hereditary connective tissue disorders such as the Ehlers-Danlos syndromes (EDS)/hypermobility spectrum disorders (HSD) and autism, both in terms of their comorbidity as well as co-occurrence within the same families. This paper reviews our current state of knowledge, as well as highlighting unanswered questions concerning this remarkable patient group, which we hope will attract further scientific interest in coming years. In particular, patients themselves are demanding more research into this growing area of interest, although science has been slow to answer that call. Here, we address the overlap between these two spectrum conditions, including neurobehavioral, psychiatric, and neurological commonalities, shared peripheral neuropathies and neuropathologies, and similar autonomic and immune dysregulation. Together, these data highlight the potential relatedness of these two conditions and suggest that EDS/HSD may represent a subtype of autism.

Methylmercury chloride exposure aggravates proinflammatory mediators and Notch-1 signaling in CD14+ and CD40+ cells and is associated with imbalance of neuroimmune function in BTBR T+ Itpr3tf/J mice

Autism spectrum disorder (ASD) is a severe neurodevelopmental disorder characterized by deficits in social interaction, communication, and repetitive behaviors. A key role for immune dysfunction has been suggested in ASD. Recent studies have indicated that inflammatory mediators and Notch-1 signaling may contribute to the development of ASD. Methylmercury chloride (MeHgCl) is an environmental pollutant that primarily affects the central nervous system, causing neurological alterations. Its effects on immunological responses have not been fully investigated in ASD. In this study, we examined the influence of MeHgCl exposure on inflammatory mediators and Notch-1 signaling in BTBR T⁺ Itpr3tf/J (BTBR) mice, a model of ASD. We examined the effects of MeHgCl on the IL-6-, GM-CSF-, NF-κB p65-, Notch-1-, and IL-27-producing CD14⁺ and CD40⁺ cells in the spleen. We assessed the effect of MeHgCl on IL-6, GM-CSF, NF-κB p65, Notch-1, and IL-27 mRNA levels in brain tissue. We also measured IL-6, GM-CSF, and NF-κB p65 protein expression levels in brain tissue. MeHgCl exposure of BTBR mice significantly increased IL-6-, GM-CSF-, NF-κB p65-, and Notch-1-, and decreased IL-27-producing CD14⁺, and CD40⁺ cells in the spleen. MeHgCl exposure of BTBR mice upregulated IL-6, GM-CSF, NF-κB p65, and Notch-1, and decreased IL-27 mRNA expression levels in brain tissue. Moreover, MeHgCl resulted in elevated expression of the IL-6, GM-CSF, and NF-κB p65 proteins in brain tissue. Taken together, these results indicate that MeHgCl exposure aggravates proinflammatory mediators and Notch-1 signaling which are associated with imbalance of neuroimmune function in BTBR mice.

Upregulation of interleukin (IL)-31, a cytokine producing CXCR1 peripheral immune cells, contributes to the immune abnormalities of autism spectrum disorder

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by communication deficits, impaired social interactions, and restricted stereotypical behaviors. Several immune cells are associated with immune dysfunction in ASD; however, IL-31 has not been explored in ASD. This study aims to investigate the role of inflammatory cytokines and transcription factors of the CXCR1 cells in children with ASD. In the current study, we investigated the cytokines and transcription factors produced by CXCR1⁺ cells (IL-31, IL-9, IL-21R, IL-21, NF-κB p65, RORγT, STAT1, and FoxP3) in peripheral blood mononuclear cells (PBMCs), from children with ASD and typically developing (TD) control children, using flow cytometric analysis. In addition, we measured mRNA and protein expression levels of IL-31 using quantitative real-time PCR and western blot analyses in PBMCs. In our study, children with ASD had increased CXCR1⁺IL-31⁺, CXCR1⁺IL-9⁺, CXCR1⁺IL-21R⁺, CXCR1⁺IL-21⁺, CXCR1⁺NF-κB⁺ p65, CXCR1⁺RORγT⁺, and CXCR1⁺STAT1⁺, and decreased CXCR1⁺FoxP3⁺ cells as compared with cells from the TD control samples. Similarly, children with ASD showed increased IL-31 mRNA and protein expression levels as compared to those of TD control samples. Our results suggest that upregulated production of inflammatory cytokines and transcription factors in CXCR1⁺ cells cause immunological imbalance in children with ASD. Therefore, attenuation of inflammatory cytokines/mediators and transcription factors could have a therapeutic potential in the treatment of ASD.

Development, phenotypes of immune cells in BTBR T+Itpr3tf/J mice

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that is characterized by a lack of social interaction, decreased verbal and non-verbal communication skills, and stereotyped repetitive behavior. There is strong evidence that a dysregulated immune response may influence neurodevelopment and thus may have a role in the development of ASD. This study focuses on the characterization of immune cell phenotypes in the BTBR T⁺Itpr3^tf/J (BTBR) mouse strain, a widely used animal model for autism research. Our study demonstrated that BTBR mice have a different immune profile compared to C57BL/6J (B6) mice, which do not display ASD-like characteristics. Thymic cells of BTBR mice have more single positive (SP) CD4⁺ and CD8⁺ T cells and fewer double positive (DP) T cells than B6 mice. The development of T cells is increased in BTBR mice with regard to the double negative (DN4) population being much higher in BTBR mice. The spleens and blood of BTBR mice also have more T helper type 1 (Th1), T helper type 2 (Th2) and T regulatory (Treg) cells compared to B6 mice. Aire expression in the thymus and spleen of BTBR mice compared to B6 mice was equivalent and lower, respectively. The mature natural killer (NK) innate immune cell population in blood and spleen is lower in BTBR than B6 mice; NK cell development is blocked prior to the double positive (DN) CD11b⁺CD27⁺ stage in BTBR mice. Since BTBR mice have more CD4⁺ T cells and elevated numbers of Th1 (T-bet⁺) and Th2 (GATA3⁺) cells, their low defense against pathogen may be explained by the lower number of NK cells and the significantly lower Th1 to Th2 ratio. The elevated number of plasma cells and autoantibodies of BTBR mice may be due to less presence and function of splenic AIRE.