Visual statistical learning in preverbal infants at a higher likelihood of autism and its association with later social communication skills.

Visual statistical Learning (SL) allows infants to extract the statistical relationships embedded in a sequence of elements. SL plays a crucial role in language and communication competencies and has been found to be impacted in Autism Spectrum Disorder (ASD). This study aims to investigate visual SL in infants at higher likelihood of developing ASD (HL-ASD) and its predictive value on autistic-related traits at 24-36 months. At 6 months of age, SL was tested using a visual habituation task in HL-ASD and neurotypical (NT) infants. All infants were habituated to a visual sequence of shapes containing statistically predictable patterns. In the test phase, infants viewed the statistically structured, familiar sequence in alternation with a novel sequence that did not contain any statistical information. HL-ASD infants were then evaluated at 24-36 months to investigate the associations between visual SL and ASD-related traits. Our results showed that NT infants were able to learn the statistical structure embedded in the visual sequences, while HL-ASD infants showed different learning patterns. A regression analysis revealed that SL ability in 6-month-old HL-ASD infants was related to social communication and interaction abilities at 24-36 months of age. These findings indicate that early differences in learning visual statistical patterns might contribute to later social communication skills.

Differentiating early sensory profiles in toddlers at elevated likelihood of autism and association with later clinical outcome and diagnosis.

LAY ABSTRACT: Early sensory responsiveness may produce cascading effects on later development, but the relation between sensory profiles and autistic diagnosis remains unclear. In a longitudinal sample of toddlers at elevated likelihood for autism, we aimed to characterize sensory subgroups and their association with clinical outcomes later on. Three sensory subgroups were described and early sensory sensitivity plays a significant role in later development and diagnosis. This study supported the importance of examining different levels of sensory patterns to dissect the phenotypic heterogeneity in sensory processing. As sensory differences are associated with later developmental outcomes, these results may be critical when designing intervention needs and support for children at increased likelihood for neurodevelopmental disorders.

Baseline EEG in the first year of life: Preliminary insights into the development of autism spectrum disorder and language impairments.

Early identification of neurodevelopmental disorders is important to ensure a prompt and effective intervention, thus improving the later outcome. Autism spectrum disorder (ASD) and language learning impairment (LLI) are among the most common neurodevelopmental disorders, and they share overlapping symptoms. This study aims to characterize baseline electroencephalography (EEG) spectral power in 6- and 12-month-old infants at higher likelihood of developing ASD and LLI, compared to typically developing infants, and to preliminarily verify if spectral power components associated with the risk status are also linked with the later ASD or LLI diagnosis. We found risk status for ASD to be associated with reduced power in the low-frequency bands and risk status for LLI with increased power in the high-frequency bands. Interestingly, later diagnosis shared similar associations, thus supporting the potential role of EEG spectral power as a biomarker useful for understanding pathophysiology and classifying diagnostic outcomes.

Atypical ERP responses to audiovisual speech integration and sensory responsiveness in infants at risk for autism spectrum disorder.

Atypical sensory responses are included in the diagnostic criteria of autism spectrum disorder (ASD). Autistic individuals perform poorly during conditions that require integration across multiple sensory modalities such as audiovisual (AV) integration. Previous research investigated neural processing of AV integration in infancy. Yet, this has never been studied in infants at higher likelihood of later ASD (HR) using neurophysiological (EEG/ERP) techniques. In this study, we investigated whether ERP measures of AV integration differentiate HR infants from low-risk (LR) infants and whether early AV integration abilities are associated with clinical measures of sensory responsiveness. At age 12 months, AV integration in HR (n = 21) and LR infants (n = 19) was characterized in a novel ERP paradigm measuring the McGurk effect, and clinical measures of sensory responsiveness were evaluated. Different brain responses over the left temporal area emerge between HR and LR infants, specifically when AV stimuli cannot be integrated into a fusible percept. Furthermore, ERP responses related to integration of AV incongruent stimuli were found to be associated with sensory responsiveness, with reduced effects of AV incongruency being associated with reduced sensory reactivity. These data suggest that early identification of AV deficits may pave the way to innovative therapeutic strategies for the autistic symptomatology. Further replications in independent cohorts are needed for generalizability of findings.

A Pilot Study Evaluating the Effects of Early Intervention for Italian Siblings of Children with Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a high-cost/high-burden problem. Early intervention may prevent development of the disorder, improving child outcomes and reducing long-term consequences. However, few studies have investigated the role of early intervention in children younger than two years. This study aims to examine the effect of early intervention in 18-month-old high-risk siblings of children with ASD (HR-ASD) with clinical signs of autism. The intervention is based on the principles of Applied Behavior Analysis and focuses on the development of early precursors to social and communicative competence (joint attention and imitation behaviors). After controlling for baseline differences, two comparison HR-ASD groups were included: 15 HR-ASD toddlers receiving behavioral intervention for 3 h per week for 5 months (INT+) and 15 HR-ASD toddlers who were only clinically monitored from age 18 months (INT-). Changes in social communication, restricted/repetitive behaviors, and language were assessed using standardized measures at pre- (T0) and post-intervention (T1). From T0 to T1, the INT+ group showed significant improvements in communication, social interaction, and language compared to INT- group. There was no effect on restricted/repetitive behaviors. Our findings highlighted the importance of early detection/intervention in autism and supported a positive impact of targeted interventions to improve outcomes in at-risk children.

Detection without further processing or processing without automatic detection? Differential ERP responses to lexical-semantic processing in toddlers at high clinical risk for autism and language disorder.

Delays in early expressive vocabulary can reflect a specific delay in language acquisition or more general impairments in social communication. The neural mechanisms underlying the (dis)ability to establish the first lexical-semantic representations remain relatively unknown. Here, we investigate the electrophysiological underpinnings of these mechanisms during the critical phase of lexical acquisition in two groups of 19-month-old toddlers at risk for neurodevelopmental disorders, i.e., children characterized by low expressive vocabulary (late talkers, N = 18) and children with early signs of Autism Spectrum Disorder (ASD, N = 18) as compared to typically developing children (N = 28), with the aim to identify similarities and specificities in lexical-semantic processing between these groups. ERPs elicited by words (either congruous or incongruous with the previous picture context) and pseudo-words are investigated within a picture-word matching paradigm. In order to further interpret ERP responses, we look at longitudinal intra-group associations with language and socio-communications skills at age 24 months. As expected, we found differences between the groups that might underlie specificities, but also similarities. On the one side, late talkers differed from the other two groups in the early component (phonological-lexical priming effect) reflecting detection of the correspondence between the heard word and the lexical representation pre-activated by the picture. On the other side, children with early symptoms of ASD differed from the other two groups in the late component (late positive component) reflecting the effortful semantic re-analysis following a violation. The functional interpretation of the two components is corroborated by significant correlations suggesting that the early component is associated with later socio-communication skills, whereas the late component is associated with linguistic skills. Results point in the direction of differential impaired mechanisms in the two populations, i.e., impaired automatic detection of incongruencies in late talkers vs. absence of high-level re-analysis of such incongruencies in children with early signs of ASD.

Effects of COVID-19 Lockdown on the Emotional and Behavioral Profiles of Preschool Italian Children with and without Familial Risk for Neurodevelopmental Disorders.

The effects of COVID-19 containment measures on the emotional and behavioral development of preschoolers are not clear. We investigated them within an ongoing longitudinal project including typically developing children (TD) and children at high familial risk for neurodevelopmental disorders (HR-NDD) who were potentially more vulnerable. The study included ninety children aged 2-6 years (TD = 48; HR-NDD = 42). Before the emergency phase (T0), all children received a clinical assessment, including the parent questionnaire Child Behavior Checklist for Ages 1.5-5 (CBCL 1.5-5). The same questionnaire was filled out again during the emergency (T1), together with an ad-hoc questionnaire investigating environmental factors characterizing the specific period. Changes in the CBCL profiles between T0 and T1 were evaluated. Overall, irrespective of familial risk, the average T-scores on specific CBCL scales at T1 were higher than at T0. Associations emerged between delta scores reflecting worsening scores on specific CBCL scales and clinical and environmental factors. Our results confirmed the negative impact of the lockdown on preschool children's emotional/behavioral profiles, and highlight the need for strategic approaches in the age range of 2-6 years, especially for more susceptible children owing to environmental factors and pre-existing emotional problems.

Dysfunctions in Infants' Statistical Learning are Related to Parental Autistic Traits.

Statistical learning refers to the ability to extract the statistical relations embedded in a sequence, and it plays a crucial role in the development of communicative and social skills that are impacted in the Autism Spectrum Disorder (ASD). Here, we investigated the relationship between infants' SL ability and autistic traits in their parents. Using a visual habituation task, we tested infant offspring of adults (non-diagnosed) who show high (HAT infants) versus low (LAT infants) autistic traits. Results demonstrated that LAT infants learned the statistical structure embedded in a visual sequence, while HAT infants failed. Moreover, infants' SL ability was related to autistic traits in their parents, further suggesting that early dysfunctions in SL might contribute to variabilities in ASD symptoms.

Paternal-but Not Maternal-Autistic Traits Predict Frontal EEG Alpha Asymmetry in Infants with Later Symptoms of Autism.

Previous research found that the parental autism phenotype is associated with child autism spectrum disorder (ASD), even if the pathway between autistic traits in parents and child ASD is still largely unknown. Several studies investigated frontal asymmetry in alpha oscillation (FAA) as an early marker for ASD. However, no study has examined the mediational effect of FAA between parental autistic traits and child ASD symptoms in the general population. We carried out a prospective study of 103 typically developing infants and measured FAA as a mediator between both maternal and paternal autistic traits and child ASD traits. We recorded infant baseline electroencephalogram (EEG) at 6 months of age. Child ASD symptoms were measured at age 24 months by the Child Behavior Checklist 1½-5 Pervasive Developmental Problems Scale, and parental autistic traits were scored by the Autism spectrum Quotient questionnaire. The mediation model showed that paternal vs. maternal autistic traits are associated with greater left FAA which, in turn, is associated with more child ASD traits with a significant indirect effect only in female infants vs. male infants. Our findings show a potential cascade of effects whereby paternal autistic traits drive EEG markers contributing to ASD risk.

Metabolic influence on the differentiation of suppressive myeloid cells in cancer.

New evidences indicate that the metabolic instruction of immunity (immune metabolism) results from the integration of cell metabolism and whole-body metabolism, which are both influenced by nutrition, microbiome metabolites and disease-driven metabolism (e.g. cancer metabolism). Cancer metabolism influences the immunological homeostasis and promotes immune alterations that support disease progression, hence influencing the clinical outcome. Cancer cells display increased glucose uptake and fermentation of glucose to lactate, even in the presence of completely functioning mitochondria. A major side effect of this event is immunosuppression, characterized by limited immunogenicity of cancer cells and restriction of the therapeutic efficacy of anticancer immunotherapy. Here, we discuss how the metabolism of myeloid cells associated with cancer contributes to the differentiation of their suppressive phenotype and therefore to cancer immune evasion.

Phenotypic and molecular changes in nodule-in-nodule hepatocellular carcinoma with pathogenetic implications.

AIMS: Nodule-in-nodule (N/N) hepatocellular carcinoma (HCC) is a convincing proof of multistep hepatocarcinogenesis. In this lesion, an inner HCC develops within an outer, more differentiated, tumour, which can be rapidly taken over by the former so that N/N HCC is rarely detected. METHODS AND RESULTS: Ten resected N/N HCCs arising in cirrhotic background and characterized: (i) as outer lesions by early (n = 3) and G1 (n = 7) HCC; (ii) as inner lesions by G1 (n = 3) and G2 (n = 7) HCC. The largest/smallest diameters of outer and inner nodules were, respectively, 20/6 mm and 16/4 mm. We investigated vascular (CD34 and endocan), hepatocellular VEGF, GS, GPC3, HSP70 and CHC) and molecular (TERT promoter and ß-catenin) changes taking place from the outer neoplastic compartment to the inner neoplastic compartment (INC). A diffuse pattern of CD34+ capillarized vessels and focal endocan immunoreactivity were major distinctive features acquired in the INC; VEGF immunoreactivity was inversely related to CD34 staining. A gain in the number of cells immunoreactive for GPC3, HSP70, and CHC, but not of GS-immunoreactive cells, also occurred in the INC. TERT promoter mutations were seen in half of the cases in both compartments, whereas ß-catenin mutations were more rarely detectable. CONCLUSIONS: Major phenotypic changes take place in the INC of N/N HCC. TERT promoter mutations take place frequently and very early, and, in contrast to ß-catenin mutations, do not appear to be acquired during N/N growth. These findings suggest that inner nodules represent a step further along the pathway of tumour progression, in contrast to earlier, simply initiated, lesions, and that complete neovascularisation predicts a change in HCC biology.

Tumor-associated myeloid cells: new understandings on their metabolic regulation and their influence in cancer immunotherapy.

Tumor-associated myeloid cells (TAMCs), mainly represented by tumor-associated macrophages and myeloid-derived suppressor cells, can promote tumor growth directly, by favoring tumor cell proliferation and survival, and indirectly, by creating an immunosuppressive microenvironment. Myeloid cells are characterized by an extreme phenotypical and functional plasticity. Immunometabolism is now emerging as a crucial aspect of TAMCs skewing toward pro-tumoral activities. The metabolic re-education of myeloid cells is a new strategy to boost their antitumor effector functions. Several anticancer therapies targeting TAMCs are already under investigation. Nowadays, the hot topic of cancer immunotherapy is represented by immune checkpoint inhibitors. These drugs unrestrain T-cell-mediated tumor elimination by removing suppressive signals delivered by tumor-associated cells. The efficacy of immune checkpoint blockade can be enhanced using coordinated strategies to counteract the TAMCs-dependent impairment of immune adaptive responses. In the first part of the review, we will describe the association between metabolic reprogramming and TAMCs biological activities. In the second part, we will illustrate the potential of combination therapies associating TAMC-targeting drugs with immune checkpoint inhibitors.

Molecular and epigenetic basis of macrophage polarized activation.

Macrophages are unique cells for origin, heterogeneity and plasticity. At steady state most of macrophages are derived from fetal sources and maintained in adulthood through self-renewing. Despite sharing common progenitors, a remarkable heterogeneity characterized tissue-resident macrophages indicating that local signals educate them to express organ-specific functions. Macrophages are extremely plastic: chromatin landscape and transcriptional programs can be dynamically re-shaped in response to microenvironmental changes. Owing to their ductility, macrophages are crucial orchestrators of both initiation and resolution of immune responses and key supporters of tissue development and functions in homeostatic and pathological conditions. Herein, we describe current understanding of heterogeneity and plasticity of macrophages using the M1-M2 dichotomy as operationally useful simplification of polarized activation. We focused on the complex network of signaling cascades, metabolic pathways, transcription factors, and epigenetic changes that control macrophage activation. In particular, this network was addressed in sepsis, as a paradigm of a pathological condition determining dynamic macrophage reprogramming.

Interleukin-1 and interferon-γ orchestrate ß-glucan-activated human dendritic cell programming via IκB-ζ modulation.

Recognition of microbial components via innate receptors including the C-type lectin receptor Dectin-1, together with the inflammatory environment, programs dendritic cells (DCs) to orchestrate the magnitude and type of adaptive immune responses. The exposure to ß-glucan, a known Dectin-1 agonist and component of fungi, yeasts, and certain immune support supplements, activates DCs to induce T helper (Th)17 cells that are essential against fungal pathogens and extracellular bacteria but may trigger inflammatory pathology or autoimmune diseases. However, the exact mechanisms of DC programming by ß-glucan have not yet been fully elucidated. Using a gene expression/perturbation approach, we demonstrate that in human DCs ß-glucan transcriptionally activates via an interleukin (IL)-1- and inflammasome-mediated positive feedback late-induced genes that bridge innate and adaptive immunity. We report that in addition to its known ability to directly prime T cells toward the Th17 lineage, IL-1 by promoting the transcriptional cofactor inhibitor of κB-ζ (IκB-ζ) also programs ß-glucan-exposed DCs to express cell adhesion and migration mediators, antimicrobial molecules, and Th17-polarizing factors. Interferon (IFN)-γ interferes with the IL-1/IκB-ζ axis in ß-glucan-activated DCs and promotes T cell-mediated immune responses with increased release of IFN-γ and IL-22, and diminished production of IL-17. Thus, our results identify IL-1 and IFN-γ as regulators of DC programming by ß-glucan. These molecular networks provide new insights into the regulation of the Th17 response as well as new targets for the modulation of immune responses to ß-glucan-containing microorganisms.

Cell depletion in mice that express diphtheria toxin receptor under the control of SiglecH encompasses more than plasmacytoid dendritic cells.

Plasmacytoid dendritic cells (pDC) produce IFN-I in response to viruses and are routinely identified in mice by SiglecH expression. SiglecH is a sialic acid-binding Ig-like lectin that has an immunomodulatory role during viral infections. In this study, we evaluated the impact of SiglecH deficiency on cytokine responses in the presence and absence of pDC. We found that lack of SiglecH enhanced IFN-I responses to viral infection, regardless of whether pDC were depleted. We also examined the expression pattern of SiglecH and observed that it was expressed by specialized macrophages and progenitors of classical dendritic cells and pDC. Accordingly, marginal zone macrophages and pDC precursors were eliminated in newly generated SiglecH-diphtheria toxin receptor (DTR)-transgenic (Tg) mice but not in CLEC4C-DTR-Tg mice after diphtheria toxin (DT) treatment. Using two bacterial models, we found that SiglecH-DTR-Tg mice injected with DT had altered bacterial uptake and were more susceptible to lethal Listeria monocytogenes infection than were DT-treated CLEC4C-DTR-Tg mice. Taken together, our findings suggest that lack of SiglecH may affect cytokine responses by cell types other than pDC during viral infections, perhaps by altering viral distribution or burden, and that cell depletion in SiglecH-DTR-Tg mice encompasses more than pDC.

Hypoxia-mediated regulation of macrophage functions in pathophysiology.

Oxygen availability affects cell differentiation, survival and function, with profound consequences on tissue homeostasis, inflammation and immunity. A gradient of oxygen levels is present in most organs of the body as well as in virtually every site of inflammation, damaged or pathological tissue. As a consequence, infiltrating leukocytes, macrophages in particular, are equipped with the capacity to shift their metabolism to anaerobic glycolysis, to generate ATP and induce the expression of factors that increase the supply of oxygen and nutrients. Strikingly, low oxygen conditions (hypoxia) and inflammatory signals share selected transcriptional events, including the activation of members of both the hypoxia-inducible factor and nuclear factor κB families, which may converge to activate specific cell programs. In the pathological response to hypoxia, cancer in particular, macrophages act as orchestrators of disease evolution and their number can be used as a prognostic marker. Here we review mechanisms of macrophage adaptation to hypoxia, their role in disease as well as new perspectives for their therapeutic targeting.

The p50 subunit of NF-κB orchestrates dendritic cell lifespan and activation of adaptive immunity.

Dendritic cells play a central role in keeping the balance between immunity and immune tolerance. A key factor in this equilibrium is the lifespan of DC, as its reduction restrains antigen availability leading to termination of immune responses. Here we show that lipopolysaccharide-driven DC maturation is paralleled by increased nuclear levels of p50 NF-κB, an event associated with DC apoptosis. Lack of p50 in murine DC promoted increased lifespan, enhanced level of maturation associated with increased expression of the proinflammatory cytokines IL-1, IL-18 and IFN-ß, enhanced capacity of activating and expanding CD4(+) and CD8(+) T cells in vivo and decreased ability to induce differentiation of FoxP3(+) regulatory T cells. In agreement, vaccination of melanoma-bearing mice with antigen-pulsed LPS-treated p50(-/-) BM-DC boosted antitumor immunity and inhibition of tumor growth. We propose that nuclear accumulation of the p50 NF-κB subunit in DC, as occurring during lipopolysaccharide-driven maturation, is a homeostatic mechanism tuning the balance between uncontrolled activation of adaptive immunity and immune tolerance.

Origin and Functions of Tumor-Associated Myeloid Cells (TAMCs).

The construction of an inflammatory microenvironment provides the fuel for cancer development and progression. Hence, solid tumors promote the expansion and the recruitment of leukocyte populations, among which tumor-associated myeloid cells (TAMCs) represent a paradigm for cancer-promoting inflammation. TAMCs group heterogeneous phagocytic populations stemming from a common myeloid progenitor (CMP), that orchestrate various aspects of cancer, including: diversion and skewing of adaptive responses; immunosuppression; cell growth; angiogenesis; matrix deposition and remodelling; construction of a metastatic niche and actual metastasis. Several evidence indicate that TAMCs show plasticity and/or functional heterogeneity, suggesting that tumour-derived factors promote their functional "reprogramming" towards protumoral activities. While recent studies have attempted to address the role of microenvironment signals, the interplay between cancer cells, innate and adaptive immunity is now emerging as a crucial step of the TAMCs reprogramming. Here we discuss the evidence for the differentiation of TAMCs during the course of tumor progression and the molecular mechanisms that regulate such event.

Hypoxia affects dendritic cell survival: role of the hypoxia-inducible factor-1α and lipopolysaccharide.

Dendritic cells (DC) are the most potent antigen-presenting cells and during their life cycle they are exposed to different oxygen tensions. Similarly to inflamed and tumor tissues, lymphoid organs are characterized by a hypoxic microenvironment; thus, the modality by which hypoxia may affect DC is important for regulating both the quality and the intensity of the immune response. Here, we show that human monocyte-derived DC, exposed to hypoxia, expressed high levels of the hypoxia-inducible factor (HIF)-1α, associated with upregulation of BNIP3 and BAX expression. This was paralleled with downregulation of the anti-apoptotic molecule Bcl-2, enhanced caspase-3 activity and poly (ADP-ribose) polymerase cleavage, along with cell death. Transfection of HIF-1α siRNA protected DC from the effects of hypoxia. Of interest, when hypoxic DC were maturated with lipopolysaccharide (LPS), we did not observe an increased cell death, while HIF-1α accumulation and BNIP3 expression were still significantly upregulated. In contrast with immature DC, mature DC expressed higher levels of Bcl-2, and, more importantly, of phosphorylated Akt. Transfection of HIF-1α siRNA to mature DC resulted in a significant upregulation of Akt phosphorylation as well. Moreover, inhibition of PI3K/Akt pathway resulted in an increased cell death of hypoxic mature DC. We may conclude that a prolonged exposure to hypoxia induces a cell death program which could be prevented by HIF-1α inhibition and/or LPS maturation. Our results may contribute to further understand the physiology of DC and the molecular mechanisms involved in the survival of DC, with important implications in the regulation of the immune response.

Macrophages in cancer and infectious diseases: the 'good' and the 'bad'.

Macrophages are crucial orchestrators of host defence and tissue homeostasis. Macrophages are heterogeneous and plastic cells that in response to different microenvironmental signals can mount a broad spectrum of different programs of polarized activation. In different pathological contexts including cancer and infectious diseases, macrophages diversity and plasticity may act as a double-edged sword. The elucidation of the molecular mechanisms underlying macrophages recruitment and functional activation allows the identification of valuable targets for the development of innovative therapeutic approaches.