Increased concentrations of P2X7R in oligodendrocyte derived extracellular vesicles of Multiple sclerosis patients.

Activation of the purinergic receptor P2X7 (P2X7R) is believed to be deleterious in autoimmune diseases and it was hypothesized to play a role in the pathogenesis of MS. P2X7R is an ATP-gated non-selective cationic channel; its activation can be driven by high concentrations of ATP and leads to the generation of large, cytolytic conductance pores. P2X7R activation can also result in apoptosis as a consequence of the activation of the caspase cascade via P2X7R-dependent stimulation of the NLRP3 inflammasome. We measured P2X7R in oligodendrocyte derived extracellular vesicles (ODEVs) in MS patients and in healthy subjects. Sixty-eight MS patients (50 relapsing-remitting, RR-MS, 18 primary progressive, PP-MS) and 57 healthy controls (HC) were enrolled. ODEVs were enriched from serum by a double step immunoaffinity method using an anti OMGp (oligodendrocyte myelin glycoprotein) antibody. P2X7R concentration was measured in ODEVs lysates by ELISA. One-way Anova test showed that P2X7R in ODEVs is significantly higher in PP-MS (mean: 1742.89 pg/mL) compared both to RR-MS (mean: 1277.33 pg/mL) (p < 0.001) and HC (mean: 879.79 pg/mL) (p < 0.001). Comparison between RR-MS and HC was also statistically significant (p < 0.001). Pearson's correlations showed that P2RX7 in ODEVs was positively correlated with EDSS (p = 0.002, r = 0.38, 0.15-0.57 95% CI) and MSSS (p = 0.004, r = 0.34, 0.12-0.54 95% CI) scores, considering MS patients together (PP-MS + RR-MS) and with disease duration in PP-MS group (p = 0.02, r = 0.53, 0.09-0.80 95% CI). Results suggest that ODEVs-associated P2X7R levels could be a biomarker for MS.

Oligomeric α-synuclein and tau aggregates in NDEVs differentiate Parkinson's disease from atypical parkinsonisms.

The early differential diagnosis of Parkinson's disease (PD) and atypical Parkinsonian syndromes (APS), including corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), is challenging because of an overlap of clinical features and the lack of reliable biomarkers. Neural-derived extracellular vesicles (NDEVs) isolated from blood provide a window into the brain's biochemistry and may assist in distinguishing between PD and APS. We verified in a case-control study whether oligomeric α-Synuclein and Tau aggregates isolated from NDEVs could allow the differential diagnosis of these conditions. Blood sampling and clinical data, including disease duration, motor severity, global cognition, and levodopa equivalent daily dose (LEDD), were collected from patients with a diagnosis of either PD (n = 70), PSP (n = 21), or CBD (n = 19). NDEVs were isolated from serum by immunocapture using an antibody against the neuronal surface marker L1CAM; oligomeric α-Synuclein and aggregated Tau were measured by ELISA. NDEVs analyses showed that oligomeric α-Synuclein is significantly augmented in PD compared to APS, whereas Tau aggregates are significantly increased in APS compared to PD (p < 0.0001). ROC analyses showed that these two biomarkers have a "good" power of classification (p < 0.0001 for both proteins), with high sensitivity and specificity, with NDEVs concentration of Tau aggregates and oligomeric α-Synuclein being respectively the best biomarker for PD/PSP and PD/CBD diagnostic differentiation. Logistic and multiple regression analysis confirmed that NDEVs-derived oligomeric α-Synuclein and Tau aggregates differentiate PD from CBD and PSP (p < 0.001). Notably, a positive correlation between NDEVs oligomeric α-Synuclein and disease severity (disease duration, p = 0.023; Modified H&Y, p = 0.015; UPDRS motor scores, p = 0.004) was found in PD patients and, in these same patients, NDEVs Tau aggregates concentration inversely correlated with global cognitive scores (p = 0.043). A minimally invasive blood test measuring the concentration of α-synuclein and Tau aggregates in NDEVs can represent a promising tool to distinguish with high sensitivity and specificity PD from CBD or PSP patients. Optimization and validation of these data will be needed to confirm the diagnostic value of these biomarkers in distinguishing synucleinopathies from taupathies.

Myelin Basic Protein in Oligodendrocyte-Derived Extracellular Vesicles as a Diagnostic and Prognostic Biomarker in Multiple Sclerosis: A Pilot Study.

Approximately 15% of multiple sclerosis (MS) patients develop a progressive form of disease from onset; this condition (primary progressive-PP) MS is difficult to diagnose and treat, and is associated with a poor prognosis. Extracellular vesicles (EVs) of brain origin isolated from blood and their protein cargoes could function as a biomarker of pathological conditions. We verified whether MBP and MOG content in oligodendrocytes-derived EVs (ODEVs) could be biomarkers of MS and could help in the differential diagnosis of clinical MS phenotypes. A total of 136 individuals (7 clinically isolated syndrome (CIS), 18 PPMS, 49 relapsing remitting (RRMS)) and 70 matched healthy controls (HC) were enrolled. ODEVs were enriched from serum by immune-capture with anti-MOG antibody; MBP and MOG protein cargoes were measured by ELISA. MBP concentration in ODEVs was significantly increased in CIS (p < 0.001), RRMS (p < 0.001) and PPMS (p < 0.001) compared to HC and was correlated with disease severity measured by EDSS and MSSS. Notably, MBP concentration in ODEVs was also significantly augmented in PPMS compared to RRMS (p = 0.004) and CIS (p = 0.03). Logistic regression and ROC analyses confirmed these results. A minimally invasive blood test measuring the concentration of MBP in ODEVs is a promising tool that could facilitate MS diagnosis.

Vitamin D Receptor Gene Polymorphism Predicts the Outcome of Multidisciplinary Rehabilitation in Multiple Sclerosis Patients.

Better knowledge about the possible role of genetic factors in modulating the response to multiple sclerosis (MS) treatment, including rehabilitation, known to promote neural plasticity, could improve the standard of care for this disease. Vitamin D receptor (VDR) gene polymorphisms are associated with MS risk, probably because of the role played by vitamin D in regulating inflammatory and reparative processes. The aim of this study was to evaluate the association of the most important functional VDR SNPs (TaqI (T/C), ApaI (A/C), and FokI (C/T)) with functional outcome in MS patients undergoing multidisciplinary inpatient rehabilitation (MDR) treatment, in order to determine whether genetic profiling might be useful to identify subjects with a higher chance of recovery. To this end, 249 MS inpatients with a diagnosis of either progressive (pMS; n = 155) or relapsing remitting (RRMS; n = 94) disease who underwent MDR treatment (average duration = 5.1 weeks) were genotyped for VDR SNPs by real-time allelic discrimination. The rehabilitation outcome was assessed using the modified Barthel Index (mBI), Expanded Disability Status Scale (EDSS), and pain numerical rating scores (NRS) at the beginning and the end of MDR treatment. A positive correlation was observed in RRMS patients between the VDR TaqI major allele (TT) and mBI increase (i.e., better functional recovery), as assessed by the linear and logistic regression analysis adjusted for gender, age, disease duration, time of hospitalization, HLA-DRB1*15.01 positivity, and number of rehabilitative interventions (Beta = 6.35; p = 0.0002). The VDR-1 TaqI, ApaI, FokI: TCC haplotype was also associated with mBI increase in RRMS patients (Beta = 3.24; p = 0.007), whereas the VDR-2: CAC haplotype was correlated with a lower mBI increase (Beta = -2.18 p = 0.04) compared with the other haplotypes. VDR TaqI major allele (TT), as well as the VDR-1 TaqI, ApaI, FokI: TCC haplotype could be associated with a better rehabilitation outcome in RRMS patients.

The Role of SNAP-25 in Autism Spectrum Disorders Onset Patterns.

Autism spectrum disorders (ASD) can present with different onset and timing of symptom development; children may manifest symptoms early in their first year of life, i.e., early onset (EO-ASD), or may lose already achieved skills during their second year of life, thus showing a regressive-type onset (RO-ASD). It is still controversial whether regression represents a neurobiological subtype of ASD, resulting from distinct genetic and environmental causes. We focused this study on the 25 kD synaptosomal-associated protein (SNAP-25) gene involved in both post-synaptic formation and adhesion and considered a key player in the pathogenesis of ASD. To this end, four single nucleotide polymorphisms (SNPs) of the SNAP-25 gene, rs363050, rs363039, rs363043, and rs1051312, already known to be involved in neurodevelopmental and psychiatric disorders, were analyzed in a cohort of 69 children with EO-ASD and 58 children with RO-ASD. Both the rs363039 G allele and GG genotype were significantly more frequently carried by patients with EO-ASD than those with RO-ASD and healthy controls (HC). On the contrary, the rs1051312 T allele and TT genotype were more frequent in individuals with RO-ASD than those with EO-ASD and HC. Thus, two different SNAP-25 alleles/genotypes seem to discriminate between EO-ASD and RO-ASD. Notably, rs1051312 is located in the 3' untranslated region (UTR) of the gene and is the target of microRNA (miRNA) regulation, suggesting a possible epigenetic role in the onset of regressive autism. These SNPs, by discriminating two different onset patterns, may represent diagnostic biomarkers of ASD and may provide insight into the different biological mechanisms towards the development of better tailored therapeutic and rehabilitative approaches.

Oligomeric Alpha-Synuclein and STX-1A from Neural-Derived Extracellular Vesicles (NDEVs) as Possible Biomarkers of REM Sleep Behavior Disorder in Parkinson's Disease: A Preliminary Cohort Study.

REM sleep behavior disorder (RBD) has a tighter link with synucleinopathies than other neurodegenerative disorders. Parkinson's Disease (PD) patients with RBD have a more severe motor and cognitive impairment; biomarkers for RBD are currently unavailable. Synaptic accumulation of α-Syn oligomers and their interaction with SNARE proteins is responsible for synaptic dysfunction in PD. We verified whether oligomeric α-Syn and SNARE components in neural-derived extracellular vesicles (NDEVs) in serum could be biomarkers for RBD. Forty-seven PD patients were enrolled, and the RBD Screening Questionnaire (RBDSQ) was compiled. A cut-off score > 6 to define probable RBD (p-RBD) and probable non-RBD (p non-RBD) was used. NDEVs were isolated from serum by immunocapture, and oligomeric α-Syn and SNARE complex components VAMP-2 and STX-1 were measured by ELISA. NDEVs' STX-1A resulted in being decreased in p-RBD compared to p non-RBD PD patients. A positive correlation between NDEVs' oligomeric α-Syn and RBDSQ total score was found (p = 0.032). Regression analysis confirmed a significant association between NDEVs' oligomeric α-Syn concentration and RBD symptoms (p = 0.033) independent from age, disease duration, and motor impairment severity. Our findings suggest that synuclein-mediated neurodegeneration in PD-RBD is more diffuse. NDEVs' oligomeric α-Syn and SNARE complex components' serum concentrations could be regarded as reliable biomarkers for the RBD-specific PD endophenotype.

Two Single Nucleotide Polymorphisms in the Purinergic Receptor P2X7 Gene Are Associated with Disease Severity in Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS) that leads to progressive physical disability. Recent evidence has suggested that P2X7 receptor (P2X7R)-mediated purinergic signalling pathways play a role in MS-associated neuroinflammation, possibly contributing to disease pathogenesis. To evaluate possible associations between P2X7R polymorphisms and MS disease severity, we performed an association study of five non-synonymous SNPs coding variants of the P2X7R gene: rs1718119 Ala348Thr, rs2230911 Thr357Ser, rs2230912 Gln460Arg, rs3751143 Glu496Ala, and rs28360457 Arg307Gln, modulating P2X7R expression in 128 MS patients (relapsing remitting MS, RRMS: n = 94; secondary progressive, SPMS: n = 34). All patients were genotyped, and multiple sclerosis severity score (MSSS) was evaluated in every case; 189 healthy subjects were enrolled as well as controls. Results showed that P2X7R rs1718119(A) 348Thr and rs22390912(G) 464Arg, two SNPs of minor allele frequency (MAF) known to confer gain of function to the P2X7R protein, were associated with significantly higher MSSS in RRMS patients alone (SMRR (p < 0.001, p = 0.01, respectively)). Interestingly, two whole haplotypes resulted in having significant association with MSSS in these same patients. Thus: (1) the P2X7R-4 "ACGAG" haplotype, characterized by the co-presence of the rs1718119-rs2230912 AG MAF alleles, was associated with higher MSSS (Beta: 1.11 p = 0.04), and (2) the P2X7R-1 "GCAAG" complementary haplotype, which contains the rs1718119 and rs2230912 GA wild-type alleles, was more frequently carried by patients with lower MSSS and less severe disease (Beta: −1.54 p < 0.001). Although being preliminary and needing confirmation in an ampler cohort, these results suggest that 348Thr and 464Arg variants have a role as modulators of disease severity in RRMS patients.

Oligomeric α-Syn and SNARE complex proteins in peripheral extracellular vesicles of neural origin are biomarkers for Parkinson's disease.

Blood-based biomarkers are needed to be used as easy, reproducible, and non-invasive tools for the diagnosis and prognosis of chronic neurodegenerative disorders including Parkinson's Disease (PD). In PD, aggregated toxic forms of α-Synuclein (α-Syn) accumulate within neurons in the brain and cause neurodegeneration; α-Syn interaction with SNARE proteins also results in synaptic disfunction. We isolated neural derived extravesicles (NDEs) from peripheral blood of 32 PD patients and 40 healthy controls (HC) and measured the concentrations of oligomeric α-Syn and of the presinaptic SNARE complex proteins: STX-1A, VAMP-2 and SNAP-25. Oligomeric α-Syn was significantly augmented whereas STX-1A and VAMP-2 were significantly reduced in NDEs of PD patients compared to HC (p < 0.001 in all cases). ROC curve analyses confirmed the discriminatory ability of NDEs oligomeric α-Syn, STX-1A and VAMP-2 levels to distinguish between PD patients and HC. Oligomeric α-Syn NDEs concentration also positively correlated with disease duration and severity of PD. These results are promising and confirm that NDEs cargoes likely reflect core pathogenic intracellular processes in their originating brain cells and could serve as novel easily accessible bio-markers. Further studies are needed to confirm results and eventually for testing rehabilitation programs and drug treatments effects.

HLA-G allelic distribution in Sardinian children with Autism spectrum disorders: A replication study.

Recent results show that in mainland Italian children with Autism spectrum disorder (ASD), HLA-G coding alleles distribution is skewed and an association between HLA-G*01:05N and ASD is present. Herein, in an independent cohort of Sardinian ASD (sASD) children and their relatives, we verify whether HLA-G allele association with ASD could be confirmed in this genetically peculiar insular population. One hundred children with a diagnosis of ASD, born in Sardinia and of Sardinian descent, 91 of their mothers, and 40 of their healthy siblings were enrolled. DNA sequencing analysis of HLA-G exon 2, 3 and 4 was used to obtain HLA-G allelic frequencies. Alleles distribution was compared with that of continental ASD children and with a control group of Caucasoid couples of multiparous women and their partners from Brazil and Denmark. Skewing of HLA-G allele distribution was replicated in sASD children; in particular, the HLA-G*01:03 allele, associated with reduced fetal tolerogenicity and development of myeloid leukemia, was more common in both ASD groups compared to controls (pc = 1 × 10-3; OR:3.5, 95%CI: 1.8-6.8). However, given the lack of data on HLA-G*01:03 allelic distribution among Sardinian healthy subjects, we cannot exclude a population effect. These data confirm an association of HLA-G locus with ASD development, particularly with those alleles linked to a lower expression of tolerogenic HLA-G protein, thus warranting further studies on HLA-G polymorphism distribution in different ASD populations.

HLA-G coding region polymorphism is skewed in autistic spectrum disorders.

Different isoforms of HLA-G protein are endowed with a differential ability to induce allogenic tolerance during pregnancy. As prenatal immune activation is suggested to play a role in the onset of autistic spectrum disorders (ASD), we evaluated HLA G*01:01-*01:06 allelic polymorphism in a cohort of Italian children affected by ASD (N=111) their mothers (N=81), and their healthy siblings (N=39). DNA sequencing analysis of HLA-G exon 2, 3 and 4 was used to obtain HLA-G allelic frequencies; alleles distribution was compared with that of two control groups of Caucasoid couples of multiparous women and their partners from Brazil and Denmark. HLA-G distribution was significantly different in ASD children compared to both control groups (Brazilian pc=1×10-4; Danish pc=1×10-3). Since HLA-G distribution was similar in the two control groups, their data were pooled. Results indicated that HLA-G*01:01 was significantly less frequent (pc=1×10-4; OR:0.5, 95%CI: 0.3-0.7) whereas HLA-G*01:05N was significantly more frequent (pc=2×10-3; OR:7.3, 95%CI: 2.4-26.6) in ASD children compared to combined controls. Finally, no clear pattern emerged when HLA-G allelic distribution was analyzed in healthy sibs. Notably, HLA-G allelic distribution found in ASD mothers was similar to that observed in the control subgroup of women with recurrent miscarriages, whilst it was significantly different compared to women without miscarriages (pc=6×10-4 df=12). Since HLA-G*01:01 is associated with the elicitation of KIR-mediated tolerogenic responses and HLA-G*01:05N correlates with NK cells activation, results herein indicate that an immune activating milieu during pregnancy is more likely observed in association with the development of ASD, similarly to what occurs in women with recurrent miscarriages.

An HLA-G(∗)14bp insertion/deletion polymorphism associates with the development of autistic spectrum disorders.

HLA-G expressed by the trophoblast ligates KIR molecules expressed by maternal NK cells at the uterine fetal/maternal interface: this interaction is involved in generating immune tolerance during pregnancy. A 14-bp insertion in the HLA-G 3'-UTR associates with significantly reduced levels of both HLA-G mRNA and soluble HLA-G, thus hampering the efficacy of HLA-G-mediated immune tolerance during pregnancy. Because prenatal immune activation is suggested to play an important role in the onset of autistic spectrum disorders (ASD) we performed an in-depth evaluation of HLA-G polymorphisms in a well-characterized cohort of Italian families of ASD children. Results showed that frequency of both homozygous 14bp+/14bp+ genotype and 14bp+ allele was significantly higher in ASD children and their mothers compared to controls (p<0.05 in all cases); analysis of the frequency of transmission of the 14bp+ allele from parents to ASD children and their non-ASD siblings showed that the 14bp+ allele was more frequently transmitted (T) to ASD children, whereas it was preferentially not transmitted (NT) to the non-ASD siblings (overall discrepancy: p=0.02; OR: 2.6, 95% CI: 1.1-6.4). Results herein suggest that HLA-G polymorphisms are associated with ASD development, possibly as a consequence of prenatal immune activation. These data infer that the immune alterations seen in ASD are associated with the maternal-fetal interaction alone, and reinforce the observation that different genetic backgrounds characterize ASD children and their non-ASD siblings.

Activating KIR molecules and their cognate ligands prevail in children with a diagnosis of ASD and in their mothers.

The activity of natural killer (NK) cells is modulated by the interaction between killer-cell immune globulin-like receptor (KIR) proteins and their cognate HLA ligands; activated NK cells produce inflammatory cytokines and mediate innate immune responses. Activating KIR/HLA complexes (aKIR/HLA) were recently suggested to prevail in children with autism spectrum disorders (ASD), a neurodevelopmental syndrome characterized by brain and behavioral abnormalities and associated with a degree of inflammation. We verified whether such findings could be confirmed by analyzing two sample cohorts of Sardinian and continental Italian ASD children and their mothers. Results showed that aKIR/HLA are increased whereas inhibitory KIR/HLA complexes are reduced in ASD children; notably this skewing was even more significant in their mothers. KIR and HLA molecules are expressed by placental cells and by the trophoblast and their interactions result in immune activation and influence fetal, as well as central nervous system development and plasticity. Data herein suggest that in utero KIR/HLA immune interactions favor immune activation in ASD; this may play a role in the pathogenesis of the disease.

VDR Gene Single Nucleotide Polymorphisms and Autoimmunity: A Narrative Review.

The vitamin D/Vitamin D receptor (VDR) axis is crucial for human health as it regulates the expression of genes involved in different functions, including calcium homeostasis, energy metabolism, cell growth and differentiation, and immune responses. In particular, the vitamin D/VDR complex regulates genes of both innate and adaptive immunity. Autoimmune diseases are believed to arise from a genetic predisposition and the presence of triggers such as hormones and environmental factors. Among these, a role for Vitamin D and molecules correlated to its functions has been repeatedly suggested. Four single nucleotide polymorphisms (SNPs) of the VDR gene, ApaI, BsmI, TaqI, and FokI, in particular, have been associated with autoimmune disorders. The presence of particular VDR SNP alleles and genotypes, thus, was observed to modulate the likelihood of developing diverse autoimmune conditions, either increasing or reducing it. In this work, we will review the scientific literature suggesting a role for these different factors in the pathogenesis of autoimmune conditions and summarize evidence indicating a possible VDR SNP involvement in the onset of these diseases. A better understanding of the role of the molecular mechanisms linking Vitamin D/VDR and autoimmunity might be extremely useful in designing novel therapeutic avenues for these disorders.

miR-23a-3p and miR-181a-5p modulate SNAP-25 expression.

SNAP-25 protein is a key protein of the SNARE complex that is involved in synaptic vesicles fusion with plasma membranes and neurotransmitter release, playing a fundamental role in neural plasticity. Recently the concentration of three specific miRNAs-miR-27b-3p, miR-181a-5p and miR-23a-3p -was found to be associated with a specific SNAP-25 polymorphism (rs363050). in silico analysis showed that all the three miRNAs target SNAP-25, but the effect of the interaction between these miRNAs and the 3'UTR of SNAP-25 mRNA is currently unknown. For this reason, we verified in vitro whether miR-27b-3p, miR-181a-5p and miR-23a-3p modulate SNAP-25 gene and protein expression. Initial experiments using miRNAs-co-transfected Vero cells and SNAP-25 3'UTR luciferase reporter plasmids showed that miR-181a-5p (p≤0.01) and miR-23a-3p (p<0.05), but not miR-27b-3p, modulate the luciferase signal, indicating that these two miRNAs bind the SNAP-25 3'UTR. Results obtained using human oligodendroglial cell line (MO3.13) transfected with miR-181a-5p or miR-27b-3p confirmed that miR-181a-5p and miR-23a-3p regulate SNAP-25 gene and protein expression. Interestingly, the two miRNAs modulate in an opposite way SNAP-25, as miR-181a-5p significantly increases (p<0.0005), whereas miR-23a-3p decreases (p<0.0005) its expression. These results for the first time describe the ability of miR-181a-5p and miR-23a-3p to modulate SNAP-25 expression, suggesting their possible use as biomarkers or as therapeutical targets for diseases in which SNAP-25 expression is altered.

SNAP-25 Polymorphisms in Autism Spectrum Disorder: A Pilot Study towards a Possible Endophenotype.

While there is substantial agreement on the diagnostic criteria for autism spectrum disorder, it is also acknowledged that it has a broad range of clinical presentations. This can complicate the diagnostic process and aggravate the choice of the most suitable rehabilitative strategy for each child. Attentional difficulties are among the most frequently reported comorbidities in autism spectrum disorder. We investigated the role of SNAP-25 polymorphisms. Synaptosome-associated protein 25 (SNAP25) is a presynaptic membrane-binding protein; it plays a crucial role in neurotransmission and has already been studied in numerous psychiatric disorders. It was also seen to be associated with hyperactivity in children with autism spectrum disorder. We collected clinical, behavioral and neuropsychological data on 41 children with a diagnosis of autism spectrum disorder, and then genotyped them for five single-nucleotide polymorphisms of SNAP-25. Participants were divided into two groups according to the Autism Diagnostic Observation Schedule (ADOS-2) Severity Score. In the group with the highest severity score, we found significant associations of clinical data with polymorphism rs363050 (A/G): children with the GG genotype had lower total IQ, more severe autistic functioning and more attentional difficulties. Our research could be the starting point for outlining a possible endophenotype among patients with autism spectrum disorder who are clinically characterized by severe autistic functioning and significant attentional difficulties.

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.

An evolutionary analysis of RAC2 identifies haplotypes associated with human autoimmune diseases.

The human RAC2 gene encodes a small GTP-binding protein with a pivotal role in immune activation and in the induction of peripheral immune tolerance through restimulation-induced cell death (RICD). Different human pathogens target the protein product of RAC2, suggesting that the gene may be subject to natural selection, and that variants in RAC2 may affect immunological phenotypes in humans. We scanned the genomic region encompassing the entire transcription unit for the presence of putative noncoding regulatory elements conserved across mammals. This information was used to select two RAC2 gene regions and analyze their intraspecific genetic diversity. Results suggest that a region covering the 3' untranslated region has been a target of multiallelic balancing selection (or diversifying selection), and three major RAC2 haplogroups occur in human populations. Haplotypes belonging to one of these clades are associated with increased susceptibility to multiple sclerosis (P = 0.022) and earlier onset of disease symptoms (P = 0.025). This same haplogroup is significantly more common in patients with Crohn's disease compared with healthy controls (P = 0.048). These data reinforce recent evidences that susceptibility alleles/haplotypes are shared among multiple autoimmune disorders and support a causal "role for RAC2" variants in the pathogenesis of autoimmune diseases. Other genes with a role in RICD have previously been associated with autoimmunity in humans, suggesting that this pathway and RAC2 may represent novel therapeutic targets in autoimmune disorders.

GC1f Vitamin D Binding Protein Isoform as a Marker of Severity in Autism Spectrum Disorders.

Autism spectrum disorders (ASD) are characterized by a wide spectrum of clinical, behavioral, and cognitive manifestations. It is, therefore, crucial to investigate possible biomarkers associated with specific ASD phenotypes. Ample literature suggests a possible role for vitamin D (VD) in influencing ASD clinical phenotypes. We analyzed three vitamin D binding protein gene (DBP) functional polymorphisms (rs2282679, rs7041, and rs4588), which are involved in the modulation of vitamin D serum concentration in 309 ASD children and 831 healthy controls. Frequency comparisons of single nucleotide polymorphisms (SNPs) alleles, genotypes, and GC isoforms (GC1f, G1s, and GC2)­generated by the combination of rs7041 and rs4588 alleles­were correlated with ASD diagnostic, behavioral, and functioning scales. The GC1f isoform was significantly more frequent in ASD compared with controls (18.6% vs. 14.5% pc = 0.02). Significantly higher scores for item 15 of the Childhood Autism Rating Scale (CARS) and lower ones for the Children's Global Assessment Scale (CGAS) functioning scales were seen in ASD carrying the GC1f isoform. In GC phenotype analysis, a gradient of severity for overall CARS scores and CARS item 15 was observed, with scores decreasing according to the presence of GC1f-GC1f > GC1f-GC1s > GC1s-GC1s > GC1f-GC2 > GC2-GC2 isoforms. Similarly, lower CGAS scores were seen in carriers of the GC1f-GC1f isoform, whereas higher scores were present in those carrying GC2-GC2 (p = 0.028). This is the first study to evaluate possible relationships between GC variants and the different aspects of ASD in Italian ASD children. Results, although needing to be validated in ampler cohorts, suggest that the GC1f isoform could be a marker of severity in ASD that may be useful in establishing the intensity of therapeutic and rehabilitative protocols.

HLA Allele Frequencies and Association with Severity of COVID-19 Infection in Northern Italian Patients.

HLA allelic distribution was analysed in a cohort of 96 Northern Italian subjects (53M/43F) (mean age 59.9 ± 13.3 years) from Lombardy who developed COVID-19 during the first two pandemic waves to investigate possible correlations between HLA molecules and disease severity. An important role of HLA- B and HLA-C loci in modulating the clinical severity of COVID-19 disease was identified. In particular, the HLA-B07 supertype was observed to be associated with a significant risk for severe disease; conversely, the HLA-B27 supertype and C*12:02 allele played a protective role as they were associated with milder disease. These associations were confirmed after applying a multinomial regression analysis to adjust the correlation for age, gender and comorbidities with COVID-19 severity. Though the power of results is limited by the small sample size, data herein contribute to shedding light on the role played by genetic background in COVID-19 infection.

Vitamin D receptor (VDR) gene SNPs influence VDR expression and modulate protection from multiple sclerosis in HLA-DRB1*15-positive individuals.

Multiple sclerosis (MS) is an autoimmune disease with a multifactorial etiology. The HLA-DRB1*15 allele, is the main genetic risk factor for MS in Caucasians; recent findings showed that the transcription of this molecule is regulated by the vitamin D/vitamin D receptor (VDR) complex. We analyzed SNPs within the VDR gene in association with the HLA-DRB1 locus in 641 MS patients diagnosed according to McDonald criteria and 558 age- and sex-matched healthy controls, to verify possible correlations between the vitamin D/VDR complex, HLA-DRB1, and susceptibility to MS. Results confirmed that HLA-DRB1*15 is a strong predisposing allele (p<1×10(-7); OR: 3.04; 95% CI: 2.02-4.60) for MS. Cosegregation analyses of VDR SNPs with HLA-DRB1*15 indicated a reduction of risk for MS given by the presence of the -DRB1*15-rs731236 T VDR haplotype (p=9.5×10(-5); OR: 2.52; 95% CI: 1.56-4.06) and, conversely, an augmented risk for disease associated with the -DRB1*15-rs731236 C VDR haplotype. Analyses performed on HLA-DRB1*15-positive MS patients and HC alone confirmed the protective role of rs731236 TT VDR genotype (p(y)=0.004; OR: 0.53; 95% CI: 0.33-0.83); notably, FACS, PCR, and confocal microscopy analyses showed that rs731236 TT genotype is associated with an augmented VDR expression in MBP-stimulated PBMC from patients. In conclusion, rs731236 TT VDR genotype modulates VDR expression and confers protection against MS in HLA-DRB1*15-positive individuals. Results herein offer a model justifying the interaction between the major genetic (HLA-DRB*15) and environmental (vitamin D) factors associated with MS onset.