Autosomal Recessive IL-12p40 Deficiency due to a Mutation in the IL12B Gene: Report of a Brazilian Patient with Lymph Node Mycobacterial Infection.

Background: Autosomal recessive interleukin (IL)-12p40 deficiency is a genetic etiology of Mendelian susceptibility to mycobacterial disease (MSMD). It has been described in ∼50 patients, usually with onset at childhood with Bacille Calmette-Guérin (BCG) and Salmonella infections. Case Presentation: A male patient born to consanguineous parents was diagnosed with presumed lymph node MSMD at the age of 13 years after ocular symptoms. A positive history of inborn error of immunity was present: BCG reaction, skin abscess, and recurrent oral candidiasis. Abnormal measurements of cytokine levels, IL-12p40 and interferon-gamma (IFN-γ), lead to the diagnosis of MSMD. Genetic analysis showed a mutation in exon 7 of the IL12B gene. Currently, the patient is alive under prophylactic antibiotics. Conclusion: We report a rare case of IL-12p40 deficiency in a Latin American patient. Medical history was crucial for immune defect suspicion, as confirmed by precision diagnostic medicine tools.

The sphingosine 1-phosphate analogue, FTY720, modulates the lipidomic signature of the mouse hippocampus.

The small-molecule drug, FTY720 (fingolimod), is a synthetic sphingosine 1-phosphate (S1P) analogue currently used to treat relapsing-remitting multiple sclerosis in both adults and children. FTY720 can cross the blood-brain barrier (BBB) and, over time, accumulate in lipid-rich areas of the central nervous system (CNS) by incorporating into phospholipid membranes. FTY720 has been shown to enhance cell membrane fluidity, which can modulate the functions of glial cells and neuronal populations involved in regulating behaviour. Moreover, direct modulation of S1P receptor-mediated lipid signalling by FTY720 can impact homeostatic CNS physiology, including neurotransmitter release probability, the biophysical properties of synaptic membranes, ion channel and transmembrane receptor kinetics, and synaptic plasticity mechanisms. The aim of this study was to investigate how chronic FTY720 treatment alters the lipid composition of CNS tissue in adolescent mice at a key stage of brain maturation. We focused on the hippocampus, a brain region known to be important for learning, memory, and the processing of sensory and emotional stimuli. Using mass spectrometry-based lipidomics, we discovered that FTY720 increases the fatty acid chain length of hydroxy-phosphatidylcholine (PCOH) lipids in the mouse hippocampus. It also decreases PCOH monounsaturated fatty acids (MUFAs) and increases PCOH polyunsaturated fatty acids (PUFAs). A total of 99 lipid species were up-regulated in the mouse hippocampus following 3 weeks of oral FTY720 exposure, whereas only 3 lipid species were down-regulated. FTY720 also modulated anxiety-like behaviours in young mice but did not affect spatial learning or memory formation. Our study presents a comprehensive overview of the lipid classes and lipid species that are altered in the hippocampus following chronic FTY720 exposure and provides novel insight into cellular and molecular mechanisms that may underlie the therapeutic or adverse effects of FTY720 in the central nervous system.

Age-related impact of social isolation in mice: Young vs middle-aged.

Social isolation is a chronic mild stressor and a significant risk factor for mental health disorders. Herein we explored the impact of social isolation on depression- and anxiety-like behaviours, as well as spatial memory impairments, in middle-aged male mice compared to post-weaning mice. We aimed to quantify and correlate social isolation-induced behaviour discrepancies with changes in hippocampal glial cell reactivity and pro-inflammatory cytokine levels. Post-weaning and middle-aged C57BL7/J6 male mice were socially isolated for a 3-week period and behavioural tests were performed on the last five days of isolation. We found that 3 weeks of social isolation led to depressive-like behaviour in the forced swim test, anxiety-like behaviour in the open field test, and spatial memory impairment in the Morris water maze paradigm in middle-aged male mice. These behavioural alterations were not observed in male mice after post-weaning social isolation, indicating resilience to isolation-mediated stress. Increased Iba-1 expression and NLRP3 priming were both observed in the hippocampus of socially isolated middle-aged mice, suggesting a role for microglia and NLRP3 pathway in the detrimental effects of social isolation on cognition and behaviour. Young socially isolated mice also demonstrated elevated NLRP3 priming compared to controls, but no differences in Iba-1 levels and no significant changes in behaviour. Ageing-induced microglia activation and enhancement of IL-1ß, TNF-α and IL-6 proinflammatory cytokines, known signs of a chronic low-grade inflammatory state, were also detected. Altogether, data suggest that social isolation, in addition to inflammaging, contributes to stress-related cognitive impairment in middle-aged mice.

Doença granulomatosa crônica: características clínicas, seguimento e terapêutica de cinco pacientes pediátricos / Chronic granulomatous disease: clinical characteristics, follow-up, and therapy of 5 pediatric patients

Introdução: A doença granulomatosa crônica (DGC) é caracterizada por um defeito na capacidade microbicida das células fagocíticas (monócitos e neutrófilos), com alta mortalidade se não diagnosticada precocemente. Os pacientes apresentam infecções recorrentes ou graves, suscetibilidade a granulomas em órgãos profundos, doenças autoimunes e doença inflamatória intestinal. Objetivo e Método: Relato de aspectos clínicos e do tratamento de cinco pacientes com doença granulomatosa crônica. Resultados: Cinco pacientes, três meninos, medianas de idade no início dos sintomas e diagnóstico de 8 meses e 48 meses, respectivamente, foram estudados por um período de 10 anos. Pneumonia (5/5) e doença micobacteriana (3/5) foram as manifestações iniciais mais comuns. Alterações pulmonares foram observadas em todos os casos. Mutações nos genes CYBB e NCF1 foram identificadas em três casos. Antibioticoprofilaxia foi instituída em todos os pacientes e três foram submetidos ao transplante de células tronco-hematopoiéticas (TCH), aos 7, 18 e 19 anos e com sobrevida atual entre 4 a 5 anos. Conclusão: O monitoramento cuidadoso de infecções graves com tratamento imediato foi crucial para a sobrevivência. O TCH, mesmo ao final da adolescência, promoveu a cura da DGC em três pacientes.

Introduction: Chronic granulomatous disease (CGD) is characterized by a defective microbicidal capacity of phagocytic cells (monocytes and neutrophils) with high mortality if not early diagnosed. Patients have recurrent or severe infections and are susceptible to granulomas in visceral organs, autoimmune diseases, and inflammatory bowel diseases. Objective and Method: To report the clinical features and treatment of 5 patients with CGD. Results: Five patients, 3 boys, with median ages at symptom onset and diagnosis of 8 months and 48 months, respectively, were followed for 10 years. Pneumonia (5/5) and mycobacterial disease (3/5) were the most common initial manifestations. Pulmonary changes were observed in all cases. Mutations in the CYBB and NCF1 genes were identified in 3 cases. All patients received antibiotic prophylaxis. Three patients underwent a hematopoietic stem cell transplant (HSCT) at 7, 18, and 19 years, with current survival of 4 to 5 years. Conclusion: Careful monitoring for severe infection with prompt treatment was crucial for survival. Even though HSCT was performed in late adolescence, it promoted the cure of CGD in 3 patients.

Reações de hipersensibilidade a vacinas / Hypersensitivity reactions to vaccines

O desenvolvimento e a ampliação do uso das vacinas durante décadas contribuíram para o controle e erradicação de doenças infecciosas, causando um grande impacto na saúde pública no mundo. A análise de segurança das vacinas percorre criteriosos processos e fases dos estudos clínicos, um dos pilares essenciais para aprovação regulatória e utilização do produto na população. O evento supostamente atribuído à vacinação e imunização (ESAVI), terminologia atual, é definido como qualquer ocorrência médica indesejada após a vacinação que possui, ou não, uma relação causal com o uso de uma vacina ou outro imunobiológico. Cabe ressaltar que eventos adversos mais raros ou inesperados, incluindo os eventos de hipersensibilidade, poderão ocorrer na fase pós-comercialização, quando as vacinas são aplicadas em milhões de pessoas. Neste artigo, serão discutidos os principais aspectos relacionados aos eventos adversos de hipersensibilidade pós-vacinais de interesse do especialista, e os desafios frente ao reconhecimento do agente causal e conduta a ser adotada. Além disso, serão revisados os potenciais alérgenos presentes nas vacinas de uso rotineiro para auxiliar o profissional de saúde na identificação de pacientes com potencial de risco de ESAVI por tais componentes. A atualização do conhecimento acerca da segurança e dos benefícios das vacinas pelos profissionais de saúde, sobretudo em populações especiais, contribui para condutas em imunização mais apropriadas, reduzindo o risco de exposição a um possível alérgeno em pessoas comprovadamente alérgicas às vacinas ou a alguns dos seus componentes, além de evitar contraindicações desnecessárias em eventos coincidentes ou não graves.

The expansion of vaccine use and development in recent decades has contributed to the control and eradication of infectious diseases, causing a major impact on public health worldwide. Vaccine safety analysis, which involves careful processes and clinical study, is one of the essential pillars of regulatory approval and use in the population. In current terminology, events supposedly attributable to vaccination and immunization (ESAVI) are defined as any unwanted medical occurrence after vaccination that may or may not have a causal relationship with vaccines or other immunobiologicals. It is noteworthy that rare or unexpected adverse events, including hypersensitivity, can occur during the post-marketing phase, when vaccines are administered to millions of people. In this article, we will discuss the main aspects of post-vaccine hypersensitivity events of interest to specialists and challenges to recognizing the causal agent and appropriate clinical practice. Potential allergens in routine vaccines will also be reviewed to help health professionals identify patients with a potential risk of ESAVI due to such components. Updating health professionals' knowledge about the safety and benefits of vaccines, particularly in special populations, can contribute to more appropriate clinical practice regarding immunization, reducing the risk of exposure to possible allergens in people with allergies to vaccines or their components, avoiding unnecessary contraindications in coincidental or non-serious events.

Immediate adverse events to intravenous immunoglobulin in pediatric patients with inborn errors of immunity: A longitudinal study with a pre-infusion protocol.

INTRODUCTION: Immunoglobulin represents the main therapy for patients with inborn errors of immunity (IEI) and it is a safe procedure, but adverse events (AEs) can occur with variable frequencies. OBJECTIVE: To evaluate the frequency of immediate AEs to intravenous immunoglobulin (IVIG) regular therapy in a pediatric cohort with IEI after a pre-IVIG infusion protocol. METHODS: This was a longitudinal study from 2011 to 2019 at a tertiary pediatric hospital in Brazil. RESULTS: A total of 1736 infusions were studied in 70 patients with IEI, 46 (65.7%) of whom were males and whose median age was 5.8 years old (range: 6 mo - 18 yo). Seven different brands of IVIG were used with the median loading dose of 0.57g/kg (range: 0.23 - 0.88g/Kg). According to the protocol, pre-medication and step-up infusion rate, were performed in 1305 (75.2%) infusions. Immediate AEs were noted in 10 children (14.3%) and in 22 (1.2%) infusions. Skin reactions (rash or urticaria) were the most common AE with 14 episodes (0.8% of all infusions). Almost all AEs were mild (19/86.4%), with no severe ones being observed. The majority of the AEs (81.8%) was identified at a 0.04ml/kg/min infusion rate. Gender, age at first infusion, presence of infection on the infusion day and change of the IVIG brand were evaluated and none of them were associated with AEs. CONCLUSION: The low frequency of immediate AEs in children with IEI highlights the safety and tolerability of intravenous immunoglobulin replacement with the procedures established at our center.

Immediate adverse events to intravenous immunoglobulin in pediatric patients with inborn errors of immunity: A longitudinal study with a pre-infusion protocol

Introduction Immunoglobulin represents the main therapy for patients with inborn errors of immunity (IEI) and it is a safe procedure, but adverse events (AEs) can occur with variable frequencies. Objective To evaluate the frequency of immediate AEs to intravenous immunoglobulin (IVIG) regular therapy in a pediatric cohort with IEI after a pre-IVIG infusion protocol. Methods This was a longitudinal study from 2011 to 2019 at a tertiary pediatric hospital in Brazil. Results A total of 1736 infusions were studied in 70 patients with IEI, 46 (65.7%) of whom were males and whose median age was 5.8 years old (range: 6 mo - 18 yo). Seven different brands of IVIG were used with the median loading dose of 0.57g/kg (range: 0.23 - 0.88g/Kg). According to the protocol, pre-medication and step-up infusion rate, were performed in 1305 (75.2%) infusions. Immediate AEs were noted in 10 children (14.3%) and in 22 (1.2%) infusions. Skin reactions (rash or urticaria) were the most common AE with 14 episodes (0.8% of all infusions). Almost all AEs were mild (19/86.4%), with no severe ones being observed. The majority of the AEs (81.8%) was identified at a 0.04ml/kg/min infusion rate. Gender, age at first infusion, presence of infection on the infusion day and change of the IVIG brand were evaluated and none of them were associated with AEs. Conclusion The low frequency of immediate AEs in children with IEI highlights the safety and tolerability of intravenous immunoglobulin replacement with the procedures established at our center.

Changes in adenosine receptors and neurotrophic factors in the SOD1G93A mouse model of amyotrophic lateral sclerosis: Modulation by chronic caffeine.

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of corticospinal tract motor neurons. Previous studies showed that adenosine-mediated neuromodulation is disturbed in ALS and that vascular endothelial growth factor (VEGF) has a neuroprotective function in ALS mouse models. We evaluated how adenosine (A1R and A2AR) and VEGF (VEGFA, VEGFB, VEGFR-1 and VEGFR-2) system markers are altered in the cortex and spinal cord of pre-symptomatic and symptomatic SOD1G93A mice. We then assessed if/how chronic treatment of SOD1G93A mice with a widely consumed adenosine receptor antagonist, caffeine, modulates VEGF system and/or the levels of Brain-derived Neurotrophic Factor (BDNF), known to be under control of A2AR. We found out decreases in A1R and increases in A2AR levels even before disease onset. Concerning the VEGF system, we detected increases of VEGFB and VEGFR-2 levels in the spinal cord at pre-symptomatic stage, which reverses at the symptomatic stage, and decreases of VEGFA levels in the cortex, in very late disease states. Chronic treatment with caffeine rescued cortical A1R levels in SOD1G93A mice, bringing them to control levels, while rendering VEGF signaling nearly unaffected. In contrast, BDNF levels were significantly affected in SOD1G93A mice treated with caffeine, being decreased in the cortex and increased in spinal the cord. Altogether, these findings suggest an early dysfunction of the adenosinergic system in ALS and highlights the possibility that the negative influence of caffeine previously reported in ALS animal models results from interference with BDNF rather than with the VEGF signaling molecules.

Microglia Depletion from Primary Glial Cultures Enables to Accurately Address the Immune Response of Astrocytes.

Astrocytes are the most abundant cells in the CNS parenchyma and play an essential role in several brain functions, such as the fine-tuning of synaptic transmission, glutamate uptake and the modulation of immune responses, among others. Much of the knowledge on the biology of astrocytes has come from the study of rodent primary astrocytic cultures. Usually, the culture is a mixed population of astrocytes and a small proportion of microglia. However, it is critical to have a pure culture of astrocytes if one wants to address their inflammatory response. If present, microglia sense the stimulus, rapidly proliferate and react to it, making it unfeasible to assess the individual responsiveness of astrocytes. Microglia have been efficiently eliminated in vivo through PLX-3397, a colony-stimulating factor-1 receptor (CSF-1R) inhibitor. In this work, the effectiveness of PLX-3397 in eradicating microglia from primary mixed glial cultures was evaluated. We tested three concentrations of PLX-3397-0.2 µM, 1 µM and 5 µM-and addressed its impact on the culture yield and viability of astrocytes. PLX-3397 is highly efficient in eliminating microglia without affecting the viability or response of cultured astrocytes. Thus, these highly enriched monolayers of astrocytes allow for the more accurate study of their immune response in disease conditions.

One-year intravenous immunoglobulin replacement therapy: efficacy in reducing hospital admissions in pediatric patients with Inborn Errors of Immunity

Abstract Objectives: To compare the frequency of hospitalization in children with Inborn Errors of Immunity with antibody deficiency previous to intravenous immunoglobulin (pre- IVIG) with a one-year period after initial IVIG (post-IVIG). Methods: Medical reports of 45 patients during an eight-year period were reviewed from 2018 to 2019. Wilcoxon-test was used for related samples. Results: Forty-five children were included in the study, aged 29-249 months of age, and most of them (64.4%) were males. Median ages at onset symptoms and at diagnosis were 6 and 73 months old, respectively. Specific antibody deficiency and unclassified hypogammaglobulinemia were the predominant diagnoses (31.1% and 17.8%, respectively). X-linked agammaglobulinemia, Hyper IgE syndrome, Hyper IgM, transient hypogammaglobulinemia of infancy, and Common Variable Immunodeficiency (CVID) were also reported, in a low frequency. Forty-four (97.8%) patients were hospitalized before IVIG, and 10 patients (22.2%) after. Annual mean hospital admission reduced from 2.5 to 0.5, pre and post-IVIG, respectively (p < 0.0001). Mean length of stay (LOS) reduced from 71 to 4.7 days/year (p < 0.0001) in general ward and in the PICU from 17.2 days/year to zero (p < 0.0002). Pneumonia was the main cause of hospital admission with a reduction in the number of episodes per patient from an average of 2.2-0.1 per year (p < 0.001). Concomitant use of antibiotic prophylaxis did not influence the number of hospital admission. Conclusion: One-year intravenous IVIG significantly decreased the number of hospitalizations and length of stay in children with impaired antibody production. Social and economic impacts would be required.

Posicionamento da ASBAI sobre a vacinação de crianças de 5 a 11 anos contra a COVID-19 com a vacina Comirnaty/ Pfizer/BioNTech ­ 27/12/2021 / ASBAI's position on vaccination of children aged 5 to 11 years against COVID-19 with the Comirnaty/Pfizer/BioNTech vaccine ­ 12/27/2021

A Associação Brasileira de Alergia e Imunologia (ASBAI) se manifesta totalmente favorável à imunização contra a COVID-19 em indivíduos entre 5 e 11 anos, para a proteção não somente deste grupo, mas também de seus conviventes. A vacinação de crianças, demonstrada sua eficácia e segurança, é fundamental para o controle da circulação do vírus e proteção de indivíduos cuja resposta vacinal pode não ocorrer de modo eficiente, como os imunocomprometidos e idosos. A imunização de pessoas entre 5 e 11 anos deve ser uma estratégia de saúde pública fundamental para o controle da pandemia que nos assola desde março de 2020 com todas as suas graves consequências para a saúde pública e a economia.

The Brazilian Association of Allergy and Immunology (ASBAI) is totally in favor of immunization against COVID-19 in individuals between 5 and 11 years old, for the protection not only of this group, but also of their cohabitants. The vaccination of children, once its efficacy and safety has been demonstrated, is essential for controlling the circulation of the virus and protecting individuals whose vaccine response may not occur efficiently, such as the immunocompromised and the elderly. The immunization of people between the ages of 5 and 11 must be a fundamental public health strategy to control the pandemic that has been plaguing us since March 2020 with all its serious consequences for public health and the economy.

Sacsin Deletion Induces Aggregation of Glial Intermediate Filaments.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disorder commonly diagnosed in infants and characterized by progressive cerebellar ataxia, spasticity, motor sensory neuropathy and axonal demyelination. ARSACS is caused by mutations in the SACS gene that lead to truncated or defective forms of the 520 kDa multidomain protein, sacsin. Sacsin function is exclusively studied on neuronal cells, where it regulates mitochondrial network organization and facilitates the normal polymerization of neuronal intermediate filaments (i.e., neurofilaments and vimentin). Here, we show that sacsin is also highly expressed in astrocytes, C6 rat glioma cells and N9 mouse microglia. Sacsin knockout in C6 cells (C6Sacs-/-) induced the accumulation of the glial intermediate filaments glial fibrillary acidic protein (GFAP), nestin and vimentin in the juxtanuclear area, and a concomitant depletion of mitochondria. C6Sacs-/- cells showed impaired responses to oxidative challenges (Rotenone) and inflammatory stimuli (Interleukin-6). GFAP aggregation is also associated with other neurodegenerative conditions diagnosed in infants, such as Alexander disease or Giant Axonal Neuropathy. Our results, and the similarities between these disorders, reinforce the possible connection between ARSACS and intermediate filament-associated diseases and point to a potential role of glia in ARSACS pathology.

One-year intravenous immunoglobulin replacement therapy: efficacy in reducing hospital admissions in pediatric patients with Inborn Errors of Immunity.

OBJECTIVES: To compare the frequency of hospitalization in children with Inborn Errors of Immunity with antibody deficiency previous to intravenous immunoglobulin (pre- IVIG) with a one-year period after initial IVIG (post-IVIG). METHODS: Medical reports of 45 patients during an eight-year period were reviewed from 2018 to 2019. Wilcoxon-test was used for related samples. RESULTS: Forty-five children were included in the study, aged 29-249 months of age, and most of them (64.4%) were males. Median ages at onset symptoms and at diagnosis were 6 and 73 months old, respectively. Specific antibody deficiency and unclassified hypogammaglobulinemia were the predominant diagnoses (31.1% and 17.8%, respectively). X-linked agammaglobulinemia, Hyper IgE syndrome, Hyper IgM, transient hypogammaglobulinemia of infancy, and Common Variable Immunodeficiency (CVID) were also reported, in a low frequency. Forty-four (97.8%) patients were hospitalized before IVIG, and 10 patients (22.2%) after. Annual mean hospital admission reduced from 2.5 to 0.5, pre and post-IVIG, respectively (p < 0.0001). Mean length of stay (LOS) reduced from 71 to 4.7 days/year (p < 0.0001) in general ward and in the PICU from 17.2 days/year to zero (p < 0.0002). Pneumonia was the main cause of hospital admission with a reduction in the number of episodes per patient from an average of 2.2-0.1 per year (p < 0.001). Concomitant use of antibiotic prophylaxis did not influence the number of hospital admission. CONCLUSION: One-year intravenous IVIG significantly decreased the number of hospitalizations and length of stay in children with impaired antibody production. Social and economic impacts would be required.

NLRP3 Inflammasome: A Starring Role in Amyloid-ß- and Tau-Driven Pathological Events in Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease commonly diagnosed among the elderly population. AD is characterized by the loss of synaptic connections, neuronal death, and progressive cognitive impairment, attributed to the extracellular accumulation of senile plaques, composed by insoluble aggregates of amyloid-ß (Aß) peptides, and to the intraneuronal formation of neurofibrillary tangles shaped by hyperphosphorylated filaments of the microtubule-associated protein tau. However, evidence showed that chronic inflammatory responses, with long-lasting exacerbated release of proinflammatory cytokines by reactive glial cells, contribute to the pathophysiology of the disease. NLRP3 inflammasome (NLRP3), a cytosolic multiprotein complex sensor of a wide range of stimuli, was implicated in multiple neurological diseases, including AD. Herein, we review the most recent findings regarding the involvement of NLRP3 in the pathogenesis of AD. We address the mechanisms of NLRP3 priming and activation in glial cells by Aß species and the potential role of neurofibrillary tangles and extracellular vesicles in disease progression. Neuronal death by NLRP3-mediated pyroptosis, driven by the interneuronal tau propagation, is also discussed. We present considerable evidence to claim that NLRP3 inhibition, is undoubtfully a potential therapeutic strategy for AD.

A Model of Epileptogenesis in Rhinal Cortex-Hippocampus Organotypic Slice Cultures.

Organotypic slice cultures have been widely used to model brain disorders and are considered excellent platforms for evaluating a drug's neuroprotective and therapeutic potential. Organotypic slices are prepared from explanted tissue and represent a complex multicellular ex vivo environment. They preserve the three-dimensional cytoarchitecture and local environment of brain cells, maintain the neuronal connectivity and the neuron-glia reciprocal interaction. Hippocampal organotypic slices are considered suitable to explore the basic mechanisms of epileptogenesis, but clinical research and animal models of epilepsy have suggested that the rhinal cortex, composed of perirhinal and entorhinal cortices, play a relevant role in seizure generation. Here, we describe the preparation of rhinal cortex-hippocampus organotypic slices. Recordings of spontaneous activity from the CA3 area under perfusion with complete growth medium, at physiological temperature and in the absence of pharmacological manipulations, showed that these slices depict evolving epileptic-like events throughout time in culture. Increased cell death, through propidium iodide uptake assay, and gliosis, assessed with fluorescence-coupled immunohistochemistry, was also observed. The experimental approach presented highlights the value of rhinal cortex-hippocampus organotypic slice cultures as a platform to study the dynamics and progression of epileptogenesis and to screen potential therapeutic targets for this brain pathology.

Vacinas COVID-19 e reações imunoalérgicas / COVID-19 vaccines and immunoallergic reactions

A avaliação dos riscos e benefícios deve ser realizada para qualquer intervenção preventiva, diagnóstica ou terapêutica em Medicina. As vacinas, assim como qualquer imunobiológico, são consagradas pelas inúmeras vantagens inerentes à proteção da saúde, apesar dos potenciais riscos de eventos adversos que, na imensa maioria das vezes, são raros, leves e controláveis. O desenvolvimento de vacinas contra o novo SARS-CoV-2 representa um dos principais anseios da população mundial e representa extraordinário avanço da Ciência. Pacientes com histórico de alergias graves a algum componente das vacinas ou a uma dose prévia de alguma delas, devem ser avaliados com cautela pelo especialista para decidir se esta deverá ser contraindicada, aplicada com supervisão médica, ou se estará indicado protocolo de dessensibilização.

The assessment of risks and benefits must be carried out for any preventive, diagnostic, or therapeutic intervention in medicine. Vaccines, like any biologic, are recognized for the innumerable advantages in public health, despite the potential risks of adverse events that, in the vast majority of cases, are rare, mild, and controllable. The development of vaccines against the new SARSCoV- 2 represents one of the main wishes of the world population as well as an extraordinary advance in science. Patients with a history of severe allergies to any component of the vaccines or reaction to a previous dose of any of them should be carefully evaluated by the specialist to decide whether vaccination should be contraindicated or administered with medical supervision, or if a desensitization protocol will be indicated.

The Neuroprotective Action of Amidated-Kyotorphin on Amyloid ß Peptide-Induced Alzheimer's Disease Pathophysiology.

Kyotorphin (KTP, l-tyrosyl-l-arginine) is an endogenous dipeptide initially described to have analgesic properties. Recently, KTP was suggested to be an endogenous neuroprotective agent, namely for Alzheimer's disease (AD). In fact, KTP levels were shown to be decreased in the cerebrospinal fluid of patients with AD, and recent data showed that intracerebroventricular (i.c.v.) injection of KTP ameliorates memory impairments in a sporadic rat model of AD. However, this administration route is far from being a suitable therapeutic strategy. Here, we evaluated if the blood-brain permeant KTP-derivative, KTP-NH2, when systemically administered, would be effective in preventing memory deficits in a sporadic AD animal model and if so, which would be the synaptic correlates of that action. The sporadic AD model was induced in male Wistar rats through i.c.v. injection of amyloid ß peptide (Aß). Animals were treated for 20 days with KTP-NH2 (32.3 mg/kg, intraperitoneally (i.p.), starting at day 3 after Aß administration) before memory testing (Novel object recognition (NOR) and Y-maze (YM) tests). Animals were then sacrificed, and markers for gliosis were assessed by immunohistochemistry and Western blot analysis. Synaptic correlates were assessed by evaluating theta-burst induced long term potentiation (LTP) of field excitatory synaptic potentials (fEPSPs) recorded from hippocampal slices and cortical spine density analysis. In the absence of KTP-NH2 treatment, Aß-injected rats had clear memory deficits, as assessed through NOR or YM tests. Importantly, these memory deficits were absent in Aß-injected rats that had been treated with KTP-NH2, which scored in memory tests as control (sham i.c.v. injected) rats. No signs of gliosis could be detected at the end of the treatment in any group of animals. LTP magnitude was significantly impaired in hippocampal slices that had been incubated with Aß oligomers (200 nM) in the absence of KTP-NH2. Co-incubation with KTP-NH2 (50 nM) rescued LTP toward control values. Similarly, Aß caused a significant decrease in spine density in cortical neuronal cultures, and this was prevented by co-incubation with KTP-NH2 (50 nM). In conclusion, the present data demonstrate that i.p. KTP-NH2 treatment counteracts Aß-induced memory impairments in an AD sporadic model, possibly through the rescuing of synaptic plasticity mechanisms.

Meningeal γδ T cell-derived IL-17 controls synaptic plasticity and short-term memory.

The notion of "immune privilege" of the brain has been revised to accommodate its infiltration, at steady state, by immune cells that participate in normal neurophysiology. However, the immune mechanisms that regulate learning and memory remain poorly understood. Here, we show that noninflammatory interleukin-17 (IL-17) derived from a previously unknown fetal-derived meningeal-resident γδ T cell subset promotes cognition. When tested in classical spatial learning paradigms, mice lacking γδ T cells or IL-17 displayed deficient short-term memory while retaining long-term memory. The plasticity of glutamatergic synapses was reduced in the absence of IL-17, resulting in impaired long-term potentiation in the hippocampus. Conversely, IL-17 enhanced glial cell production of brain-derived neurotropic factor, whose exogenous provision rescued the synaptic and behavioral phenotypes of IL-17-deficient animals. Together, our work provides previously unknown clues on the mechanisms that regulate short-term versus long-term memory and on the evolutionary and functional link between the immune and nervous systems.

Ex vivo model of epilepsy in organotypic slices-a new tool for drug screening.

BACKGROUND: Epilepsy is a prevalent neurological disorder worldwide. It is characterized by an enduring predisposition to generate seizures and its development is accompanied by alterations in many cellular processes. Organotypic slice cultures represent a multicellular environment with the potential to assess biological mechanisms, and they are used as a starting point for refining molecules for in vivo studies. Here, we investigated organotypic slice cultures as a model of epilepsy. METHODS: We assessed, by electrophysiological recordings, the spontaneous activity of organotypic slices maintained under different culture protocols. Moreover, we evaluated, through molecular-based approaches, neurogenesis, neuronal death, gliosis, expression of proinflammatory cytokines, and activation of NLRP3 inflammasome (nucleotide-binding, leucine-rich repeat, pyrin domain) as biomarkers of neuroinflammation. RESULTS: We demonstrated that organotypic slices, maintained under a serum deprivation culture protocol, develop epileptic-like activity. Furthermore, throughout a comparative study with slices that do not depict any epileptiform activity, slices with epileptiform activity were found to display significant differences in terms of inflammation-related features, such as (1) increased neuronal death, with higher incidence in CA1 pyramidal neurons of the hippocampus; (2) activation of astrocytes and microglia, assessed through western blot and immunohistochemistry; (3) upregulation of proinflammatory cytokines, specifically interleukin-1ß (IL-1ß), interleukin-6, and tumor necrosis factor α, revealed by qPCR; and (4) enhanced expression of NLRP3, assessed by western blot, together with increased NLRP3 activation, showed by IL-1ß quantification. CONCLUSIONS: Thus, organotypic slice cultures gradually deprived of serum mimic the epileptic-like activity, as well as the inflammatory events associated with in vivo epilepsy. This system can be considered a new tool to explore the interplay between neuroinflammation and epilepsy and to screen potential drug candidates, within the inflammatory cascades, to reduce/halt epileptogenesis.

CD40 ligand deficiency causes functional defects of peripheral neutrophils that are improved by exogenous IFN-γ.

BACKGROUND: Patients with X-linked hyper-IgM syndrome caused by CD40 ligand (CD40L) deficiency often present with episodic, cyclic, or chronic neutropenia, suggesting abnormal neutrophil development in the absence of CD40L-CD40 interaction. However, even when not neutropenic and despite immunoglobulin replacement therapy, CD40L-deficient patients are susceptible to life-threatening infections caused by opportunistic pathogens, suggesting impaired phagocyte function and the need for novel therapeutic approaches. OBJECTIVES: We sought to analyze whether peripheral neutrophils from CD40L-deficient patients display functional defects and to explore the in vitro effects of recombinant human IFN-γ (rhIFN-γ) on neutrophil function. METHODS: We investigated the microbicidal activity, respiratory burst, and transcriptome profile of neutrophils from CD40L-deficient patients. In addition, we evaluated whether the lack of CD40L in mice also affects neutrophil function. RESULTS: Neutrophils from CD40L-deficient patients exhibited defective respiratory burst and microbicidal activity, which were improved in vitro by rhIFN-γ but not soluble CD40L. Moreover, neutrophils from patients showed reduced CD16 protein expression and a dysregulated transcriptome suggestive of impaired differentiation. Similar to CD40L-deficient patients, CD40L knockout mice were found to have impaired neutrophil responses. In parallel, we demonstrated that soluble CD40L induces the promyelocytic cell line HL-60 to proliferate and mature by regulating the expression of genes of the same Gene Ontology categories (eg, cell differentiation) when compared with those dysregulated in peripheral blood neutrophils from CD40L-deficient patients. CONCLUSION: Our data suggest a nonredundant role of CD40L-CD40 interaction in neutrophil development and function that could be improved in vitro by rhIFN-γ, indicating a potential novel therapeutic application for this cytokine.