Persistence of dysfunctional natural killer cells in adults with high-functioning autism spectrum disorders: stigma/consequence of unresolved early infectious events?

Regional skull translocator protein elevation in autistic adults detected by PET-MRI

Immune processes have been implicated in the pathophysiology of autism spectrum disorder (ASD). Brain borders, such as the skull, have recently been highlighted as sites where neuro-immune interactions occur with key consequences for brain immunity. Translocator protein (TSPO), a mitochondrial protein involved in immune functions, was measured in the skull using [11C]PBR28 positron emission tomography-magnetic resonance imaging (PET-MRI) in 38 autistic adults (26 males, 12 females) and 29 age-and sex-matched healthy controls (19 males, 10 females). [11C]PBR28 uptake relative to a pseudo-reference region assessed using standardized uptake value ratio (SUVR) revealed elevated TSPO in autistic adults in frontal and temporal skull. We did not observe an association between [11C]PBR28 uptake in total or regional skull areas and autism symptom severity. C-reactive protein levels were positively associated with [11C]PBR28 uptake in the total skull across participants. Lastly, [11C]PBR28 uptake in the total skull was stable across a 4-month period. This work indicates regional TSPO elevations in the skull in autistic adults, which may suggest immune involvement.

Low-dose interleukin-2 in patients with bipolar depression: A phase 2 randomised double-blind placebo-controlled trial

Immune abnormalities including an insufficiency of regulatory T cells (Treg) and increased blood-based inflammatory markers have been observed in bipolar disorders (BD), particularly during depression. As Tregs are pivotal to control inflammation, Treg stimulation by low-dose IL-2 (IL-2LD) could have a therapeutic impact on bipolar depression. We performed a randomized, double-blind, placebo-controlled (2 active: 1 placebo) proof-of-concept trial of add-on IL-2LD in patients with bipolar depression. Patients received a placebo or IL-2LD (1MIU) once a day for 5 days, and then once a week for 4 weeks starting on week 2. The primary objective was to demonstrate a biological Treg response to IL-2LD assessed by fold increase in Treg percentage of CD4 + cells from baseline to day 5. Secondary objectives included safety assessment and mood improvement throughout the study period. This trial is registered with ClinicalTrials.gov, number NCT04133233. Fourteen patients with bipolar depression were included, with 4 receiving placebo and 10 IL-2LD. Baseline clinical and biological characteristics were balanced between groups. The primary evaluation criterion was met, with IL-2LD expanding 1.17 [95 % CI 1.01-1.34] vs 1.01 [95 % CI 0.90-1.12] (p = 0.0421) and activating Tregs. Secondary evaluation criteria were also met with significant improvements of depressive symptoms and global functioning from day-15 onwards in the IL-2LD treated patients. The treatment was well-tolerated, with no serious adverse events related to treatment. This proof-of-concept trial shows that stimulating Tregs in patients with bipolar depression is safe and associated with clinical improvements. This supports a pathophysiological role of inflammation in BD and warrants pursuing the evaluation of IL-2LD as an adjunct treatment of major mood disorders.

Identification of immune traits associated with neurodevelopmental disorders by two-sample Mendelian randomization analysis

BACKGROUND

One of the main causes of health-related issues in children is neurodevelopmental disorders (NDDs), which include attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and Tourette syndrome (TS). Nonetheless, there is relatively little prior research looking at the link between immunological inflammation and NDDs. Our work uses a two-sample Mendelian Randomization (MR) approach to provide a thorough evaluation of the causal effects of immune traits on ADHD, ASD, and TS.

METHODS

As exposures, 731 immunological traits' genetic associations were chosen, and the outcomes were genome-wide association data for ADHD, ASD, and TS. The inverse-variance weighted (IVW), weighted median (WM), and MR-Egger methods were used to conduct MR analysis. The results' robustness, heterogeneity, and horizontal pleiotropy were confirmed using extensive sensitivity analysis.

RESULTS

With single-nucleotide polymorphisms serving as instruments and false discovery rate (FDR) correction applied, the study found that significantly higher expression of CD62L on CD62L+ myeloid DC (IVW, OR: 0.926, 95% CI 0.896~0.958, P = 9.42 × 10-6, FDR = 0.007) and suggestively higher absolute cell count (AC) of CD28 + DN (CD4-CD8-) (IVW, OR: 0.852, 95% CI = 0.780 ∼ 0.932, P-value = 4.65 × 10-4, FDR = 0.170) was associated with a lower risk of ADHD. There was no pleiotropy, and the causal relationships were strong according to sensitivity, leave-one-out, and MR-Steiger directionality tests. For ASD and TS, no harmful or protective immune traits were observed.

CONCLUSIONS

The results of the study lend credence to the theory that deficiency in CD62L on CD62L+ myeloid DC and CD28 + DN (CD4-CD8) AC may contribute to the onset of ADHD.

Dysregulated plasma autoantibodies are associated with B cell dysfunction in young Arab children with autism spectrum disorder in Qatar

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and communication, as well as the occurrence of stereotyped and repetitive behaviors. Previous studies have provided solid evidence of dysregulated immune system in ASD; however, limited studies have investigated autoantibody profiles in individuals with ASD. This study aims to screen plasma autoantibodies in a well-defined cohort of young children with ASD (n = 100) and their matched controls (n = 60) utilizing a high-throughput KoRectly Expressed (KREX) i-Ome protein-array technology. We identified differential protein expression of 16 autoantibodies in ASD, which were correlated with differential gene expression of these markers in independent ASD cohorts. Meanwhile, we identified a distinct list of 33 autoantibodies associated with ASD severity; several of which were correlated with maternal age and birth weight in ASD. In addition, we found dysregulated numbers of circulating B cells and activated HLADR+ B cells in ASD, which were correlated with altered levels of several autoantibodies. Further in-depth analysis of B cell subpopulations revealed an increased frequency of activated naïve B cells in ASD, as well as an association of resting naïve B cells and transitional B cells with ASD severity. Pathway enrichment analysis revealed disrupted MAPK signaling in ASD, suggesting a potential relevance of this pathway to altered autoantibodies and B cell dysfunction in ASD. Finally, we found that a combination of eight autoantibodies associated with ASD severity showed an area under the curve (ROC-AUC) of 0.937 (95% CI = 0.890, 0.983; p < 0.001), which demonstrated the diagnostic accuracy of the eight-marker signature in the severity classification of ASD cases. Overall, this study determined dysregulated autoantibody profiles and B cell dysfunction in children with ASD and identified an eight-autoantibody panel for ASD severity classification.

Association between NKG2/KLR gene variants and epilepsy in Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a set of neurodevelopmental disorders mainly characterized by repetitive, restrictive and stereotypical behaviors, and impaired communication skills. Several lines of evidence indicate that alterations of the immune system account for ASD development, including the presence of brain-reactive antibodies, abnormal T cell activation, altered cytokine levels in brain, cerebrospinal fluid and peripheral blood circulation, increased levels of circulating monocytes, and dysregulation in Natural Killer (NK) cells activity. Regarding NK cells, a lower cytotoxic activity, a higher level of activation and an increased number of these cells in individuals with ASD have been described. In 2019, a study showed that NK cells derived from patients with ASD show a characteristic pattern of NKG2C overexpression, highlighting the importance of the NK cell pathway in ASD. In fact, the study of genes related to NK cell activity has proven to be an excellent research target, both in terms of susceptibility as well as a marker for the different clinical manifestations observed in ASD individuals. Here, we evaluated the influence of KLRC2 gene deletion as well as KLRK1 rs1049174 and rs2255336 variants in a cohort of 185 children diagnosed with ASD and their respective biological parents in southern Brazil. Of note, this is the first study concerning genetic variants of the KLRC2 and KLRK1 genes in an ASD sample. The KLRC2 gene deletion (p = 0.001; pc = 0.009), KLRK1 rs1049174 (p = 0.005; pc = 0.045) and KLRK1 rs2255336 (p = 0.001; pc = 0.009) were associated with epilepsy in ASD patients. The results indicate that KLRC2 deletion, KLRK1 rs2255336, and KLRK1 rs1049174 could be involved in epilepsy manifestation in ASD patients, possibly impacting the NK dysregulation already described in ASD and epileptic patients.

Alterations of natural killer cells activatory molecules phenotype and function in mothers of ASD children: a pilot study

Introduction

Autism spectrum disorder (ASD) is accompanied by complex immune alterations and inflammation, and the possible role played by Natural Killer (NK) in such alterations is only barely understood.

Methods

To address this question we analysed activating and inhibitory NK receptors, as well as NK cells phenotype and function in a group of mothers of children who developed ASD (ASD-MO; N=24) comparing results to those obtained in mothers of healthy children who did not develop (HC-MO; N=25).

Results

Results showed that in ASD-MO compared to HC-MO: 1) NK cells expressing the inhibitory receptor ILT2 are significantly decreased; 2) the activating HLA-G14bp+ polymorphism is more frequently observed and is correlated with the decrease of ILT2-expressing cells; 3) the CD56bright and CD56dim NK subsets are increased; 4) IFNγ and TNF production is reduced; and 5) perforin- and granzymes-releasing NK cells are increased even in unstimulated conditions and could not be upregulated by mitogenic stimulation.

Discussion

Results herein reinforce the hypothesis that ASD relatives present traits similar to, but not as severe as the defining features of ASD (Autism endophenotype) and identify a role for NK cells impairment in generating the inflammatory milieu that is observed in ASD.

A human leukocyte antigen imputation study uncovers possible genetic interplay between gut inflammatory processes and autism spectrum disorders

Autism spectrum disorders (ASD) are neurodevelopmental conditions that are for subsets of individuals, underpinned by dysregulated immune processes, including inflammation, autoimmunity, and dysbiosis. Consequently, the major histocompatibility complex (MHC)-hosted human leukocyte antigen (HLA) has been implicated in ASD risk, although seldom investigated. By utilizing a GWAS performed by the EU-AIMS consortium (LEAP cohort), we compared HLA and MHC genetic variants, single nucleotide polymorphisms (SNP), and haplotypes in ASD individuals, versus typically developing controls. We uncovered six SNPs, namely rs9268528, rs9268542, rs9268556, rs14004, rs9268557, and rs8084 that crossed the Bonferroni threshold, which form the underpinnings of 3 independent genetic pathways/blocks that differentially associate with ASD. Block 1 (rs9268528-G, rs9268542-G, rs9268556-C, and rs14004-A) afforded protection against ASD development, whilst the two remaining blocks, namely rs9268557-T, and rs8084-A, associated with heightened risk. rs8084 and rs14004 mapped to the HLA-DRA gene, whilst the four other SNPs located in the BTNL2 locus. Different combinations amongst BTNL2 SNPs and HLA amino acid variants or classical alleles were found either to afford protection from or contribute to ASD risk, indicating a genetic interplay between BTNL2 and HLA. Interestingly, the detected variants had transcriptional and/or quantitative traits loci implications. As BTNL2 modulates gastrointestinal homeostasis and the identified HLA alleles regulate the gastrointestinal tract in celiac disease, it is proposed that the data on ASD risk may be linked to genetically regulated gut inflammatory processes. These findings might have implications for the prevention and treatment of ASD, via the targeting of gut-related processes.

Exploring potential impacts of pregnancy-related maternal immune activation and extracellular vesicles on immune alterations observed in autism spectrum disorder

Autism Spectrum Disorder (ASD) is a set of neurodevelopmental disorders usually observed in early life, with impacts on behavioral and social skills. Incidence of ASD has been dramatically increasing worldwide, possibly due to increase in awareness/diagnosis as well as to genetic and environmental triggers. Currently, it is estimated that ∼1% of the world population presents ASD symptoms. In addition to its genetic background, environmental and immune-related factors also influence the ASD etiology. In this context, maternal immune activation (MIA) has recently been suggested as a component potentially involved in ASD development. In addition, extracellular vesicles (EVs) are abundant at the maternal-fetal interface and are actively involved in the immunoregulation required for a healthy pregnancy. Considering that alterations in concentration and content of EVs have also been associated with ASD, this article raises a debate about the potential roles of EVs in the processes surrounding MIA. This represents the major differential of the present review compared to other ASD studies. To support the suggested correlations and hypotheses, findings regarding the roles of EVs during pregnancy and potential influences on ASD are discussed, along with a review and update concerning the participation of infections, cytokine unbalances, overweight and obesity, maternal anti-fetal brain antibodies, maternal fever, gestational diabetes, preeclampsia, labor type and microbiota unbalances in MIA and ASD.

Transforming the understanding of brain immunity

Contemporary studies have completely changed the view of brain immunity from envisioning the brain as isolated and inaccessible to peripheral immune cells to an organ in close physical and functional communication with the immune system for its maintenance, function, and repair. Circulating immune cells reside in special niches in the brain's borders, the choroid plexus, meninges, and perivascular spaces, from which they patrol and sense the brain in a remote manner. These niches, together with the meningeal lymphatic system and skull microchannels, provide multiple routes of interaction between the brain and the immune system, in addition to the blood vasculature. In this Review, we describe current ideas about brain immunity and their implications for brain aging, diseases, and immune-based therapeutic approaches.

Activating NKG2C Receptor: Functional Characteristics and Current Strategies in Clinical Applications

The interest in NK cells and their cytotoxic activity against tumour, infected or transformed cells continuously increases as they become a new efficient and off-the-shelf agents in immunotherapies. Their actions are balanced by a wide set of activating and inhibitory receptors, recognizing their complementary ligands on target cells. One of the most studied receptors is the activating CD94/NKG2C molecule, which is a member of the C-type lectin-like family. This review is intended to summarise latest research findings on the clinical relevance of NKG2C receptor and to examine its contribution to current and potential therapeutic strategies. It outlines functional characteristics and molecular features of CD94/NKG2C, its interactions with HLA-E molecule and presented antigens, pointing out a key role of this receptor in immunosurveillance, especially in the human cytomegalovirus infection. Additionally, the authors attempt to shed some light on receptor's unique interaction with its ligand which is shared with another receptor (CD94/NKG2A) with rather opposite properties.

Novel insights into the immune cell landscape and gene signatures in autism spectrum disorder by bioinformatics and clinical analysis

The pathogenesis of autism spectrum disorder (ASD) is not well understood, especially in terms of immunity and inflammation, and there are currently no early diagnostic or treatment methods. In this study, we obtained six existing Gene Expression Omnibus transcriptome datasets from the blood of ASD patients. We performed functional enrichment analysis, PPI analysis, CIBERSORT algorithm, and Spearman correlation analysis, with a focus on expression profiling in hub genes and immune cells. We validated that monocytes and nonclassical monocytes were upregulated in the ASD group using peripheral blood (30 children with ASD and 30 age and sex-matched typically developing children) using flow cytometry. The receiver operating characteristic curves (PSMC4 and ALAS2) and analysis stratified by ASD severity (LIlRB1 and CD69) showed that they had predictive value using the "training" and verification groups. Three immune cell types - monocytes, M2 macrophages, and activated dendritic cells - had different degrees of correlation with 15 identified hub genes. In addition, we analyzed the miRNA-mRNA network and agents-gene interactions using miRNA databases (starBase and miRDB) and the DSigDB database. Two miRNAs (miR-342-3p and miR-1321) and 23 agents were linked with ASD. These findings suggest that dysregulation of the immune system may contribute to ASD development, especially dysregulation of monocytes and monocyte-derived cells. ASD-related hub genes may serve as potential predictors for ASD, and the potential ASD-related miRNAs and agents identified here may open up new strategies for the prevention and treatment of ASD.

In search of immune cellular sources of abnormal cytokines in the blood in autism spectrum disorder: A systematic review of case-control studies

Abnormal cytokine levels in circulating blood have been repeatedly reported in autism; however, the underlying cause remains unclear. This systematic review aimed to investigate cytokine levels in peripheral blood compartments and identify their potential immune cellular sources in subjects with autism through comparison with controls. We conducted an electronic database search (PubMed, Scopus, ProQuest Central, Ovid, SAGE Journals, and Wiley Online Library) from inception (no time limits) to July 9, 2020, and identified 75 relevant articles. Our qualitative data synthesis focused on results consistently described in at least three independent studies, and we reported the results according to the PRISMA protocol. We found that compared with controls, in subjects with autism, cytokines IL-6, IL-17, TNF-α, and IL-1β increased in the plasma and serum. We also identified monocytes, neutrophils, and CD4+ T cells as potential sources of these elevated cytokines in autism. Cytokines IFN-γ, TGF-β, RANTES, and IL-8 were increased in the plasma/serum of subjects with autism, and IFN-γ was likely produced by CD4+ T cells and natural killer (NK) cells, although conflicting evidence is present for IFN-γ and TGF-β. Other cytokines-IL-13, IL-10, IL-5, and IL-4-were found to be unaltered in the plasma/serum and post-stimulated blood immune cells in autistic individuals as compared with controls. The frequencies of T cells, monocytes, B cells, and NK cells were unchanged in subjects with autism as opposed to controls, suggesting that abnormal cytokines were unlikely due to altered cell numbers but might be due to altered functioning of these cells in autism. Our results support existing studies of abnormal cytokines in autism and provide comprehensive evidence of potential cellular sources of these altered cytokines in the context of autism.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020205224, identifier [CRD42020205224].

Inflammation and Autophagy: A Convergent Point between Autism Spectrum Disorder (ASD)-Related Genetic and Environmental Factors: Focus on Aluminum Adjuvants

Autism spectrum disorder (ASD), schizophrenia, and bipolar disorder are genetically complex and heterogeneous neurodevelopmental disorders (NDDs) resulting from genetic factors and gene-environment (GxE) interactions for which onset occurs in early brain development. Recent progress highlights the link between ASD and (i) immunogenetics, neurodevelopment, and inflammation, and (ii) impairments of autophagy, a crucial neurodevelopmental process involved in synaptic pruning. Among various environmental factors causing risk for ASD, aluminum (Al)-containing vaccines injected during critical periods have received special attention and triggered relevant scientific questions. The aim of this review is to discuss the current knowledge on the role of early inflammation, immune and autophagy dysfunction in ASD as well as preclinical studies which question Al adjuvant impacts on brain and immune maturation. We highlight the most recent breakthroughs and the lack of epidemiological, pharmacokinetic and pharmacodynamic data constituting a "scientific gap". We propose additional research, such as genetic studies that could contribute to identify populations at genetic risk, improving diagnosis, and potentially the development of new therapeutic tools.

Plasticity of natural killer cells in pregnant patients infected with SARS-CoV-2 and their neonates during childbirth

The COVID-19 pandemic has occurred due to infection caused by the SARS-CoV-2 coronavirus, which impacts gestation and pregnancy. In SARS-CoV-2 infection, only very rare cases of vertical transmission have been reported, suggesting that fetal immune imprinting due to a maternal infection is probably a result of changes in maternal immunity. Natural killer (NK) cells are the leading maternal immune cells that act as a natural defense system to fight infections. They also play a pivotal role in the establishment and maintenance of pregnancy. While peripheral NK cells display specific features in patients infected with SARS-CoV-2 in the general population, information remains elusive in pregnant mothers and neonates. In the present study, we analyzed the characteristics of NK cells isolated from both neonatal umbilical cord blood and maternal peripheral blood close to the time of delivery. Phenotype and functions were compared in 18 healthy pregnant women and 34 COVID-19 patients during pregnancy within an ongoing infection (PCR+; N = 15) or after recovery (IgG+PCR-; N = 19). The frequency of NK cells from infected women and their neonates was correlated with the production of inflammatory cytokines in the serum. The expression of NKG2A and NKp30, as well as degranulation of NK cells in pregnant women with ongoing infection, were both negatively correlated to estradiol level. Furthermore, NK cells from the neonates born to infected women were significantly decreased and also correlated to estradiol level. This study highlights the relationship between NK cells, inflammation, and estradiol in patients with ongoing infection, providing new insights into the impact of maternal SARS-CoV-2 infection on the neonate.

Natural killer cells in first-episode psychosis: an innate immune signature?

Accumulating evidence majorly implicates immune dysfunction in the etiology of psychotic disorders. In particular, altered numbers and functions of natural killer (NK) cells have been described in psychosis, but interpretation has often been confounded by a number of biases, including treatment. Eighty-one first-episode psychosis (FEP) patients who subsequently received a diagnosis of either schizophrenia (SZ; n = 30) or bipolar disorder (BP; n = 31) over a five-year follow-up period were investigated for their NK cell phenotype and compared to 61 healthy controls (HCs). We found a similar proportion of CD3^-CD56⁺ NK cells in FEP patients and HCs. The frequency of NK cells expressing the late cell activation marker HLA-DR was significantly increased in FEP patients compared to HCs, especially in patients with BP (p < 0.0001) and, to a lesser degree, in patients with SZ (p = 0.0128). Interestingly, the expression of the activating NKG2C receptor, known to be associated with infections, was higher in patients with SZ and BP than in HCs (p < 0.0001) and correlated with HLA-DR expression, altogether defining adaptive NK cells. In terms of NK cell function, we observed a suppressed capacity of SZ-derived NK cells to mount cytotoxic responses in the presence of target cells, while NK cells from patients with BP show an inability to produce IFN-γ, a cytokine pivotal to NK function. This study strongly suggests major dysfunction of NK cells in FEP with functioning impairment correlated with psychotic, manic, and depressive symptoms in subsequently diagnosed patients with SZ and BP.

Distinct immunopathological mechanisms of EBV-positive and EBV-negative posttransplant lymphoproliferative disorders

EBV-positive and EBV-negative posttransplant lymphoproliferative disorders (PTLDs) arise in different immunovirological contexts and might have distinct pathophysiologies. To examine this hypothesis, we conducted a multicentric prospective study with 56 EBV-positive and 39 EBV-negative PTLD patients of the K-VIROGREF cohort, recruited at PTLD diagnosis and before treatment (2013-2019), and compared them to PTLD-free Transplant Controls (TC, n = 21). We measured absolute lymphocyte counts (n = 108), analyzed NK- and T cell phenotypes (n = 49 and 94), and performed EBV-specific functional assays (n = 16 and 42) by multiparameter flow cytometry and ELISpot-IFNγ assays (n = 50). EBV-negative PTLD patients, NK cells overexpressed Tim-3; the 2-year progression-free survival (PFS) was poorer in patients with a CD4 lymphopenia (CD4⁺ <300 cells/mm³ , p <  .001). EBV-positive PTLD patients presented a profound NK-cell lymphopenia (median = 60 cells/mm³ ) and a high proportion of NK cells expressing PD-1 (vs. TC, p = .029) and apoptosis markers (vs. TC, p < .001). EBV-specific T cells of EBV-positive PTLD patients circulated in low proportions, showed immune exhaustion (p = .013 vs. TC) and poorly recognized the N-terminal portion of EBNA-3A viral protein. Altogether, this broad comparison of EBV-positive and EBV-negative PTLDs highlight distinct patterns of immunopathological mechanisms between these two diseases and provide new clues for immunotherapeutic strategies and PTLD prognosis.

Nonameric Peptide Orchestrates Signal Transduction in the Activating HLA-E/NKG2C/CD94 Immune Complex as Revealed by All-Atom Simulations

The innate immune system's natural killer (NK) cells exert their cytolytic function against a variety of pathological challenges, including tumors and virally infected cells. Their activation depends on net signaling mediated via inhibitory and activating receptors that interact with specific ligands displayed on the surfaces of target cells. The CD94/NKG2C heterodimer is one of the NK activating receptors and performs its function by interacting with the trimeric ligand comprised of the HLA-E/β2m/nonameric peptide complex. Here, simulations of the all-atom multi-microsecond molecular dynamics in five immune complexes provide atomistic insights into the receptor-ligand molecular recognition, as well as the molecular events that facilitate the NK cell activation. We identify NKG2C, the HLA-Eα2 domain, and the nonameric peptide as the key elements involved in the molecular machinery of signal transduction via an intertwined hydrogen bond network. Overall, the study addresses the complex intricacies that are necessary to understand the mechanisms of the innate immune system.

Autism spectrum disorders and natural killer cells: a review on pathogenesis and treatment

Introduction: Autism spectrum disorder (ASD), as a wide spectrum of neurodevelopmental disorders, is characterized by early-onset impairments in social-communication, repetitive behaviors, and restrictive interests.Areas covered: Although still unknown, there are some pieces of evidence suggesting altered immune function in the etiology of ASD. This review aims to summarize studies linking Natural Killer (NK) cells to ASD by searching through databases like MEDLINE and Scopus up to October 2020. NK cells play important roles in the innate immune system and immune regulation. As parts of the immune system, they interact with the neural system as well. Immune dysregulations such as autoimmunity and improper immune responses to both internal and external stimulations, especially in early developmental stages of the brain, may induce neurodevelopmental disorders. NK cells' dysfunction in children with ASD as well as their parents have been highlighted in many studies.Expert opinion: Changes in the frequency, gene expressions, cytotoxicity features, and receptors of NK cells are reported in children with ASD. Immune therapy for children with ASD with immune abnormality has shown promising results. However, further studies are needed to elucidate the exact role of NK cells in the pathogenesis of ASD providing future treatment options for these children.

Preeclampsia Drives Molecular Networks to Shift Toward Greater Vulnerability to the Development of Autism Spectrum Disorder

Preeclampsia (PE) confers a significant risk for subsequent diagnosis with autism spectrum disorder (ASD), with the mechanisms underlying this observation being largely unknown. To identify molecular networks affected by both PE and ASD, we conducted a large-scale literature data mining and a gene set enrichment analysis (GSEA), followed by an expression mega-analysis in 13 independently profiled ASD datasets. Sets of genes implicated in ASD and in PE significantly overlap (156 common genes; p = 3.14E⁻⁶⁷), with many biological pathways shared (94 pathways; p < 1.00E⁻²¹). A set of PE-driven molecular triggers possibly contributing to worsening the risk of subsequent ASD was identified, possibly representing a regulatory shift toward greater vulnerability to the development of ASD. Mega-analysis of expression highlighted RPS4Y1, an inhibitor of STAT3 that is expressed in a sexually dimorphic manner, as a contributor to both PE and ASD, which should be evaluated as a possible contributor to male predominance in ASD. A set of PE-driven molecular triggers may shift the developing brain toward a greater risk of ASD. One of these triggers, chromosome Y encoded gene RPS4Y1, an inhibitor of STAT3 signaling, warrants evaluation as a possible contributor to male predominance in ASD.