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

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

Exosomes in HIV infection: A review and critical look.

Exosomes are nanovesicles released into the extracellular medium by different cell types. These vesicles carry a variety of protein and RNA cargos, and have a central role in cellular signaling and regulation. A PubMed search using the term "exosomes" finds 67 articles published in 2006. Ten years later, the same search returns approximately 1200 results for 2016 alone. The growing interest in exosomes within the scientific community reflects the different roles exerted by extracellular vesicles in biological systems and diseases. However, the increase in academic production addressing the biological function of exosomes causes much confusion, especially where the focus is on the role of exosomes in pathological situations. In this review, we critically interpret the current state of the research on exosomes and HIV infection. It is plausible to assume that exosomes influence the pathogenesis of HIV infection through their biological cargo (primarily membrane proteins and microRNAs). On the other hand, evidence for a usurpation of the exosomal budding and trafficking machinery by HIV during infection is limited, although such a mechanism cannot be ruled out. This review also discusses several biological aspects of exosomal function in the immune system. Finally, the limitations of current exosome research are pointed out.

Vitamin D receptor polymorphisms and expression profile in rheumatoid arthritis Brazilian patients.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and important joint commitment, being the most common systemic autoimmune disease worldwide. RA displays important genetic background with a variety of genes contributing to the immune balance breakdown. Recent studies have demonstrated that vitamin D, through its receptor (VDR), is able to regulate the immune balance and suppress the autoimmunity process, being a potential target in autoimmune diseases. In the present genetic association study, we assessed 5 Tag single nucleotide polymorphisms (SNPs) (rs11168268, rs2248098, rs1540339, rs4760648 and rs3890733), which cover most of the VDR gene, in three different Brazilian populations (from Northeast, Southeast and South Brazil). We also evaluated the VDR expression profile in whole blood and monocytes from RA patients. For genotyping study, 428 RA patients and 616 healthy controls were genotyped with fluorogenic allele specific probes on an ABI7500 platform. For gene expression study, VDR mRNA levels of 15 RA patients and 26 healthy individuals were assessed by RT-PCR. Our results showed that SNPs rs4760648 and rs3890733 are associated to RA susceptibility (p value = 0.0026, OR 1.31 and p value = 0.0091, OR 1.28 with statistical power = 0.999 and 0.993, respectively). Regarding RA clinical features, the studied SNPs did not show significant associations. The gene expression assays showed that VDR mRNA levels were down regulated in both whole blood (-3.3 fold) and monocytes (-3.2 fold) of RA patients when compared to healthy controls. Our results, the first reported for distinct Brazilian populations, support a role of the VDR gene in the susceptibility to RA.

The paradox of high availability and low recognition of soluble HLA-G by LILRB1 receptor in rheumatoid arthritis patients.

HLA-G is a regulatory molecule involved in immunologic tolerance. Growing evidence indicates that HLA-G plays a role in the regulation of inflammatory processes and autoimmune diseases. This study aimed at a systematic evaluation of soluble HLA-G (sHLA-G) in plasma of rheumatoid arthritis (RA) patients with long-lasting chronic inflammation. RA patients (n=68) and healthy controls (n=26) had their plasmatic sHLA-G measured by ELISA whereas the binding capability of sHLA-G to its cognate LILRB1 receptor was measured by a Luminex-based assay. All subjects were PCR-genotyped for HLA-G 14 bp polymorphism (rs66554220). Significantly higher sHLA-G levels were observed in patients (p<0.001), however no significant differences were observed in LILRB1 binding capacity between RA patients and controls. Remarkably, the proportion of patients presenting specific binding of sHLA-G to LILRB1 was significantly decreased as compared to controls (56% vs. 81%, p=0.027). Patients without rheumatoid factor (RF-) were significantly overrepresented in the group of patients positive for LILRB1 binding as compared to patients without LILRB1 binding (31% vs 10%, p=0.033). Furthermore, methotrexate treated patients (n=58) revealed significantly lower LILRB1 binding to sHLA-G molecules than non-treated patients (medians: 12.2 vs. 67.7 units/ml, p=0.031). Unlike in controls, no significant differences in sHLA-G levels were observed among patients grouped by 14 pb genotype. Thus, in a substantial number of late RA patients, the circulating sHLA-G molecules are impaired regarding LILRB1 recognition, meaning that although increased levels are observed; these molecules are not qualified to exert their protective functions against inflammation. Our findings offer new insights into the immunopathology of RA patients with long-lasting anti-RA-treatment and highlight the importance to also measure the binding capability of sHLA-G to LILRB1.

Influence of HLA-G polymorphisms in human immunodeficiency virus infection and hepatitis C virus co-infection in Brazilian and Italian individuals.

OBJECTIVE: This study aimed to investigate the role of Human Leukocyte Antigen (HLA)-G in the susceptibility to HIV-1 infection through the analysis of the HLA-G 3' untranslated region (UTR) polymorphisms 14 bp insertion/deletion (rs66554220) and +3142C>G (rs1063320). DESIGN: We analyzed 582 HIV-1 infected patients and 626 uninfected individuals from Brazil and Italy in a case-control study. METHODS: HLA-G polymorphisms were genotyped using PCR, PCR-RFLP assays or direct sequencing. All analyses were stratified by ethnicity. Genotypic, allelic and diplotypic frequencies were compared between HIV-1 infected subjects and controls using Chi-square or Fischer exact tests. Also, haplotypic frequencies were estimated using MLocus software. RESULTS: African-derived HIV-infected individuals presented a higher frequency of the 14 bp insertion allele as compared to non-infected individuals (0.468 versus 0.373, respectively; p(Bonf) = 0.010). A higher frequency of the 14 bp insertion +3142G (insG) haplotype (0.456 versus 0.346, p<0.001) and the insG/insG diplotype (OR=1.88, 95%CI = 1.08-3.23, p=0.021) was observed among African-derived patients as compared to uninfected controls. Also, we observed a higher frequency of the ins/ins genotype among African-derived HIV patients co-infected with HCV (OR=2.78, 95%CI = 1.20-6.49, p = 0.008). CONCLUSIONS: Our data point out to an increased frequency of alleles and genotypes associated with low HLA-G expression among African-derived patients, suggesting a potential role for HLA-G in the susceptibility to HIV-1 infection and HCV co-infection in those individuals.

O papel do gene e da molécula HLA-G na expressão clínica das doenças reumatológicas / The role of the HLA-G gene and molecule on the clinical expression of rheumatologic diseases

O antígeno leucocitário humano G (HLA-G) é uma molécula não clássica de complexo principal de histocompatibilidade (MHC) de classe I, caracterizada por baixo polimorfismo em sua região codificadora, um padrão de distribuição tecidual limitado em condições fisiológicas e expressão por meio de isoformas solúveis e acopladas à superfície de membranas por meio de splicing alternativo. O HLA-G é bastante conhecido por estar envolvido na indução e na manutenção da tolerância entre o sistema imunológico materno e o feto semialogênico ao nível da interface fetoplacentária. Além disso, diversos estudos apontam para um papel imunorregulatório mais amplo dessa molécula. Neste contexto, a expressão de HLA-G em doenças inflamatórias e reumatológicas é uma área relativamente recente de pesquisa. Os primeiros estudos descreveram a expressão de HLA-G em várias miopatias inflamatórias, dermatite atópica e psoríase cutânea. Com base nos achados de que o HLA-G poderia desviar respostas T helper para o tipo Th2, foi levantada a hipótese de que o HLA-G seria uma molécula protetora nas respostas inflamatórias. Neste artigo, revisamos os potenciais papéis da molécula HLA-G no sistema imunológico e em diversas doenças reumatológicas, tais como lúpus eritematoso sistêmico, artrite reumatoide, esclerose sistêmica e outras.

Human leukocyte antigen G (HLA-G) is a non-classic class I major histocompatibility complex (MHC) molecule characterized by low polymorphism in its coding region, a limited tissue distribution pattern in physiologic conditions, and expression through soluble isoforms and isoforms bound to surface membranes through alternative splicing. HLA-G is fairly known since it is involved in induction and maintenance of tolerance between the maternal immunologic system and the semi-allogeneic fetus at the level of the fetal-placental interface. Besides, several studies have indicated a wider immunoregulatory role of this molecule. In this context, the expression of HLA-G in inflammatory and rheumatologic diseases is a relatively recent research area. The first studies described the expression of HLA-G in several inflammatory myopathies, atopic dermatitis, and cutaneous psoriasis. Based on the findings that HLA-G could divert T helper responses to the Th2 type, it was hypothesized that HLA-G would be a protective molecule in inflammatory responses. In this article, we review the potential roles of the HLA-G molecule in the immune system and in several rheumatologic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and others.

The role of the HLA-G gene and molecule on the clinical expression of rheumatologic diseases.

Human leukocyte antigen G (HLA-G) is a non-classic class I major histocompatibility complex (MHC) molecule characterized by low polymorphism in its coding region, a limited tissue distribution pattern in physiologic conditions, and expression through soluble isoforms and isoforms bound to surface membranes through alternative splicing. HLA-G is fairly known since it is involved in induction and maintenance of tolerance between the maternal immunologic system and the semi-allogeneic fetus at the level of the fetal-placental interface. Besides, several studies have indicated a wider immunoregulatory role of this molecule. In this context, the expression of HLA-G in inflammatory and rheumatologic diseases is a relatively recent research area. The first studies described the expression of HLA-G in several inflammatory myopathies, atopic dermatitis, and cutaneous psoriasis. Based on the findings that HLA-G could divert T helper responses to the Th2 type, it was hypothesized that HLA-G would be a protective molecule in inflammatory responses. In this article, we review the potential roles of the HLA-G molecule in the immune system and in several rheumatologic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and others.

Mannose-binding lectin gene polymorphisms in Brazilian patients with rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a disease with unknown etiology but it is probably multifactorial. RA susceptibility is related to genetic, hormonal, immunologic, and environmental factors. Mannose-binding lectin (MBL) is an important protein of the human innate immune system, encoded by the MBL2 gene. Polymorphisms in MBL2 were associated with several diseases, and may be an important factor in RA susceptibility. We analyzed 3 MBL2 gene polymorphisms in 322 Brazilian patients with RA and 345 ethnically matched healthy controls. METHODS: MBL2 gene variants were analyzed through polymerase chain reaction sequencing. RESULTS: Considering MBL2 B, C, and D alleles separately, a significant difference in both genotypic and allelic frequencies, particularly concerning frequency of the C allele, was observed comparing European-derived and African-derived individuals (European-derived patients 0.022 vs African-derived patients 0.205; European-derived controls 0.029 vs African-derived controls 0.144; both p < 0.001). We also analyzed MBL2 genotype in relation to extraarticular manifestations. Considering MBL2 variants together, we found an increased frequency of the OO genotype among patients with rheumatoid nodules (p = 0.031), although this association lost significance after Bonferroni correction. CONCLUSION: Our findings suggest an association of MBL2 genotypes with some clinical manifestations of RA, but more studies are needed to clarify the actual role of MBL in RA.

New evidence for balancing selection at the HLA-G locus in South Amerindians.

HLA-G is a non-classical HLA (Human Leukocyte Antigen) molecule characterized by limited tissue distribution under normal physiological conditions and low variability at both DNA and protein levels. Several studies suggest that HLA-G could play a role, as an immunoregulatory molecule, in situations as diverse as transplantation, cancer, viral infections and inflammatory diseases. A total of 237 individuals from 21 South American tribes speaking nine different linguistic families were studied in relation to the 14 bp insertion/deletion polymorphism at the HLA-G gene. A consistent (seven in nine) excess of heterozygosity in samples classified by language was obtained. Our data supply evidences for balancing selection acting at the HLA-G 14 bp INDEL region. Enhanced fetal survival in a pathogen-rich environment may account for these findings.

Aspectos clínico-patológicos e controle da paratuberculose em rebanho bovino leiteiro / Clinic-pathological aspects and control of paratuberculosis in a dairy cattle herd

A paratuberculose ou doença de Johne é uma enterite granulomatosa causada por Mycobacterium avium subsp. paratuberculosis. Descrevem-se os aspectos epidemiológicos, clínico-patológicos e laboratoriais da paratuberculose em rebanho bovino leiteiro no município de Rio Claro, região Sul do Estado do Rio de Janeiro. No período de 2006 a 2009, oito vacas adultas da raça Girolanda apresentaram diarreia crônico-intermitente e perda progressiva de peso. À necropsia, observaram-se linfonodos mesentéricos aumentados de volume e úmidos ao corte, vasos linfáticos subserosos das alças intestinais proeminentes, serosa do intestino com aspecto anelado e cerebroide e a mucosa espessada, pregueada e com aspecto microgranular. À microscopia havia, desde o duodeno até o reto, inflamação granulomatosa difusa, marcada dilatação dos vasos linfáticos no ápice das vilosidades, linfangiectasia e linfangite granulomatosa na submucosa, muscular e serosa. A inflamação granulomatosa também foi vista nos linfonodos mesentéricos. A coloração de Ziehl-Neelsen revelou variável quantidade de bacilos álcool-ácido resistentes no interior de macrófagos, de células gigantes de Langhans e livres na mucosa e submucosa dos intestinos delgado e grosso e em linfonodos mesentéricos. Em alguns animais, a lâmina própria da mucosa, principalmente do jejuno e íleo exibia acentuada hipertrofia. Mycobacterium avium subsp. paratuberculosis foi isolado em cultivo bacteriano de Herrold com micobactina, a partir de amostras de fezes, de raspado de mucosa intestinal e de leite e identificado pela técnica de PCR IS900. Através da avaliação sorológica semestral, foram analisadas 298 vacas do mesmo rebanho a partir de três anos de idade, observou-se cerca de 40 por cento de animais reagentes ao teste ELISA indireto no período estudado. O diagnóstico da paratuberculose foi baseado nos dados clínico-patológicos, na sorologia, no isolamento e identificação do agente através de cultivo bacteriano e PCR IS900. Após implementação de medidas de controle, tais como eliminação de animais doentes, abate seletivo dos animais soropositivos, separação dos bezerros ao nascer e utilização de banco de colostro, observou-se, nos três anos de estudo, diminuição da ocorrência de casos clínicos no rebanho, de seis casos por ano para cerca de um caso por ano.

Paratuberculosis (Johne's disease) is a granulomatous enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis. Epidemiology, clinic-pathological and laboratorial aspects of paratuberculosis in a dairy cattle herd are described. The disease was diagnosed from 2006 to 2009 in eight cows that presented chronic-intermittent diarrhea and chronic weight loss, in the Rio Claro municipality, Rio de Janeiro. At necropsy, the subserosal lymphatic vessels were proeminent and dilated, mesenteric nodes were enlarged and intestinal mucosa was corrugated, thickened and of microgranular aspect. From duodenum to the rectum, histopathology revealed severe and diffuse granulomatous inflammation of the lamina propria and submucosa, broadened and distorted villi, dilatation of the lymphatic vessels in their apex, lymphangioectasia and granulomatous lymphangitis in the submucosa. Ziehl-Neelsen stain showed variable amounts of acid-fast bacilli in macrophages, in Langhans giant cells and freely in the mucosa and submucosa of the small intestine, colon and lymphnodes. In some cows, the lamina propria presented severe hypertrophy, mainly in the jejunum and ileum. Mycobacterium avium subsp. paratuberculosis was isolated through bacterial cultivation of samples taken from feces, intestinal mucosa and milk, and identified through IS900 PCR. From 298 cows older than three years, the percentage of reactive animals was 40 percent by indirect ELISA test. The diagnosis of paratuberculosis was based on clinic-epidemiological data, serology, bacterial isolation in Herrold egg yolk medium with micobactin and on IS900 PCR. After the adoption of control measures, as slaughter of cows with clinical signs, selective slaughter of seropositive cows, removal of the calf from the dam at birth, and use of the colostrum bank, we observed a reduction from six clinical cases to only one case per year, in the last three years of the study.

Association of the HLA-G 14-bp insertion/deletion polymorphism with juvenile idiopathic arthritis and rheumatoid arthritis.

We tested the possible association of the 14-bp polymorphism of the HLA-G gene in the course of two inflammatory diseases, rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). Patients and controls were genotyped for the 14-bp polymorphism by polymerase chain reaction with specific primers for the exon 8 of the human leukocyte antigen (HLA)-G gene and the amplified fragment was visualized in a 6% polyacrylamide gel. A total of 106 JIA patients, 265 RA patients, 356 healthy adults and 85 healthy children were genotyped for the 14-bp polymorphism. Female JIA patients presented a higher frequency of the -14 bp allele when compared with female healthy children (0.743 and 0.500, corrected P=0.003), which reflected in the JIA group as a whole. This increased frequency of the -14-bp allele was observed in all JIA subtypes. In RA patients, no differences in allelic and genotypic frequencies were observed between patients and controls. No correlations were observed among genotype and disease severity or clinical manifestations. Our data suggest that the HLA-G -14 bp allele is probably a risk factor for JIA, mainly in females. Considering the differences observed in relation to gender, we suggest that hormonal differences can interfere with the development of JIA. Considering the RA patients, our data agree with results from the literature and highlight the differences in the etiology of RA and JIA.

Immunogenetics of pregnancy: role of a 14-bp deletion in the maternal HLA-G gene in primiparous pre-eclamptic Brazilian women.

The etiology and pathogenesis of pre-eclampsia (PE) involve a combination of maternal-fetal genetic and immunologic factors. The immunologic maladaptation theory of PE predicts that the maternal immune system does not tolerate the semi-allogeneic fetus. Human leukocyte antigen-G (HLA-G) is expressed in some types of immune cells as well as in the fetal-maternal interface by trophoblasts, playing an immunoregulatory role. Here we have evaluated a 14-bp deletion polymorphism in the 3'-untranslated region of exon 8 of HLA-G gene in pregnant PE women and controls. HLA-G genotypes in both control and PE women were in Hardy-Weinberg equilibrium. The healthy pregnant and PE women had similar genotype frequencies (p = 0.789). This was similarly observed when PE women were subgrouped accordingly to severity of disease (p = 0.646). However, the primiparous PE women presented a tendency toward higher frequency of the 14-bp deletion allele (0.442) compared with the primiparous healthy women (0.286), p = 0.09. Our data suggest that the maternal 14-bp deletion of HLA-G is not associated with the risk for PE but that it could affect the development of PE in primiparous women.