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1.
Cell ; 186(23): 5114-5134.e27, 2023 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-37875108

RESUMO

Human inherited disorders of interferon-gamma (IFN-γ) immunity underlie severe mycobacterial diseases. We report X-linked recessive MCTS1 deficiency in men with mycobacterial disease from kindreds of different ancestries (from China, Finland, Iran, and Saudi Arabia). Complete deficiency of this translation re-initiation factor impairs the translation of a subset of proteins, including the kinase JAK2 in all cell types tested, including T lymphocytes and phagocytes. JAK2 expression is sufficiently low to impair cellular responses to interleukin-23 (IL-23) and partially IL-12, but not other JAK2-dependent cytokines. Defective responses to IL-23 preferentially impair the production of IFN-γ by innate-like adaptive mucosal-associated invariant T cells (MAIT) and γδ T lymphocytes upon mycobacterial challenge. Surprisingly, the lack of MCTS1-dependent translation re-initiation and ribosome recycling seems to be otherwise physiologically redundant in these patients. These findings suggest that X-linked recessive human MCTS1 deficiency underlies isolated mycobacterial disease by impairing JAK2 translation in innate-like adaptive T lymphocytes, thereby impairing the IL-23-dependent induction of IFN-γ.


Assuntos
Interferon gama , Janus Quinase 2 , Infecções por Mycobacterium , Humanos , Masculino , Proteínas de Ciclo Celular/metabolismo , Interferon gama/imunologia , Interleucina-12 , Interleucina-23 , Janus Quinase 2/metabolismo , Mycobacterium/fisiologia , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/metabolismo , Proteínas Oncogênicas/metabolismo
2.
Nat Immunol ; 25(5): 764-777, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609546

RESUMO

The linear ubiquitin assembly complex (LUBAC) consists of HOIP, HOIL-1 and SHARPIN and is essential for proper immune responses. Individuals with HOIP and HOIL-1 deficiencies present with severe immunodeficiency, autoinflammation and glycogen storage disease. In mice, the loss of Sharpin leads to severe dermatitis due to excessive keratinocyte cell death. Here, we report two individuals with SHARPIN deficiency who manifest autoinflammatory symptoms but unexpectedly no dermatological problems. Fibroblasts and B cells from these individuals showed attenuated canonical NF-κB responses and a propensity for cell death mediated by TNF superfamily members. Both SHARPIN-deficient and HOIP-deficient individuals showed a substantial reduction of secondary lymphoid germinal center B cell development. Treatment of one SHARPIN-deficient individual with anti-TNF therapies led to complete clinical and transcriptomic resolution of autoinflammation. These findings underscore the critical function of the LUBAC as a gatekeeper for cell death-mediated immune dysregulation in humans.


Assuntos
Síndromes de Imunodeficiência , Proteínas do Tecido Nervoso , Ubiquitinas , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Feminino , Masculino , NF-kappa B/metabolismo , Ubiquitina-Proteína Ligases/genética , Inflamação/imunologia , Inflamação/genética , Linfócitos B/imunologia , Mutação com Perda de Função , Fibroblastos/metabolismo , Fibroblastos/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Animais , Camundongos , Alelos
3.
Am J Hum Genet ; 109(8): 1421-1435, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35830857

RESUMO

PPFIBP1 encodes for the liprin-ß1 protein, which has been shown to play a role in neuronal outgrowth and synapse formation in Drosophila melanogaster. By exome and genome sequencing, we detected nine ultra-rare homozygous loss-of-function variants in 16 individuals from 12 unrelated families. The individuals presented with moderate to profound developmental delay, often refractory early-onset epilepsy, and progressive microcephaly. Further common clinical findings included muscular hyper- and hypotonia, spasticity, failure to thrive and short stature, feeding difficulties, impaired vision, and congenital heart defects. Neuroimaging revealed abnormalities of brain morphology with leukoencephalopathy, ventriculomegaly, cortical abnormalities, and intracranial periventricular calcifications as major features. In a fetus with intracranial calcifications, we identified a rare homozygous missense variant that by structural analysis was predicted to disturb the topology of the SAM domain region that is essential for protein-protein interaction. For further insight into the effects of PPFIBP1 loss of function, we performed automated behavioral phenotyping of a Caenorhabditis elegans PPFIBP1/hlb-1 knockout model, which revealed defects in spontaneous and light-induced behavior and confirmed resistance to the acetylcholinesterase inhibitor aldicarb, suggesting a defect in the neuronal presynaptic zone. In conclusion, we establish bi-allelic loss-of-function variants in PPFIBP1 as a cause of an autosomal recessive severe neurodevelopmental disorder with early-onset epilepsy, microcephaly, and periventricular calcifications.


Assuntos
Epilepsia , Microcefalia , Malformações do Sistema Nervoso , Transtornos do Neurodesenvolvimento , Acetilcolinesterase/genética , Animais , Drosophila melanogaster/genética , Epilepsia/genética , Perda de Heterozigosidade , Microcefalia/genética , Transtornos do Neurodesenvolvimento/genética , Linhagem
4.
J Clin Immunol ; 43(1): 217-228, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36227411

RESUMO

Major histocompatibility complex class I (MHC-I) deficiency, also known as bare lymphocyte syndrome type 1 (BLS-1), is a rare autosomal recessively inherited immunodeficiency disorder with remarkable clinical and biological heterogeneity. Transporter associated with antigen processing (TAP) is a member of the ATP-binding cassette superfamily of transporters and consists of two subunits, TAP1 or TAP2. Any defect resulting from a mutation or deletion of these two subunits may adversely affect the peptide translocation in the endoplasmic reticulum, which is an important process for properly assembling MHC-I molecules. To date, only 12 TAP2-deficient patients were reported in the literature. Herein, we described two Iranian cases with 2 and 3 decades of delayed diagnosis of chronic necrotizing granulomatous skin lesions due to TAP2 deficiency without pulmonary involvement. Segregation analysis in family members identified 3 additional homozygous asymptomatic carriers. In both asymptomatic and symptomatic carriers, HLA-I expression was only 4-15% of the one observed in healthy controls. We performed the first deep immunophenotyping in TAP2-deficient patients. While total CD8 T cell counts were normal as previously reported, the patients showed strongly impaired naïve CD8 T cell counts. Mucosal-associated invariant T (MAIT) cells and invariant natural killer T (iNKT) cell counts were increased.


Assuntos
Membro 3 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Antígenos de Histocompatibilidade Classe I , Imunodeficiência Combinada Severa , Humanos , Apresentação de Antígeno/genética , Membro 3 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/genética , Diagnóstico Tardio , Granuloma/genética , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Irã (Geográfico) , Imunodeficiência Combinada Severa/genética
5.
J Clin Immunol ; 43(8): 1941-1952, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37584719

RESUMO

PURPOSE: Major histocompatibility complex class II (MHC-II) deficiency is a rare inborn error of immunity (IEI). Impaired antigen presentation to CD4 + T cells results in combined immunodeficiency (CID). Patients typically present with severe respiratory and gastrointestinal tract infections at early ages. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy. METHODS: We describe the clinical, immunologic, and genetic features of eighteen unrelated Iranian patients with MHC-II deficiency. RESULTS: Consanguinity was present in all affected families. The median age at the initial presentation was 5.5 months (range 7 days to 18 years). The main symptoms included failure to thrive, persistent diarrhea, and pneumonia. Autoimmune and neurologic features were also documented in about one-third of the patients, respectively. Thirteen patients carried RFXANK gene mutations, two carried RFX5 gene mutations, and three carried a RFXAP gene mutation. Six patients shared the same RFXANK founder mutation (c.162delG); limited to the Iranian population and dated to approximately 1296 years ago. Four of the patients underwent HSCT; three of them are alive. On the other hand, nine of the fourteen patients who did not undergo HSCT had a poor prognosis and died. CONCLUSION: MHC-II deficiency is not rare in Iran, with a high rate of consanguinity. It should be considered in the differential diagnosis of CID at any age. With the limited access to HSCT and its variable results in MHC-II deficiency, implementing genetic counseling and family planning for the affected families are mandatory. We are better determined to study the c.162delG RFXANK heterozygous mutation frequency in the Iranian population.


Assuntos
Proteínas de Ligação a DNA , Imunodeficiência Combinada Severa , Fatores de Transcrição , Humanos , Recém-Nascido , Proteínas de Ligação a DNA/genética , Antígenos de Histocompatibilidade Classe II/genética , Irã (Geográfico) , Mutação/genética , Imunodeficiência Combinada Severa/genética , Fatores de Transcrição/genética
6.
BMC Plant Biol ; 22(1): 367, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35879654

RESUMO

Maize (Zea mays) growth performance has been hindered due to the high soil salinity. Salinity is one of the most severe abiotic stresses that has led to growth imbalance and profitability of harvests in arid and semi-arid regions. Plants have taken advantage of salt-tolerant bacteria as plant growth-promoters to enhance growth and reduce the adverse effects of salinity through the regulation of some biochemical, physiological, and molecular features. Preferences for non-chemical, eco-friendly, and economical approaches have caused the inquiry of the Bacillus genus as a joint group of plant growth-promoting rhizobacteria known to alleviate salt-stress impacts. In the present study, halotolerant Bacillus strains were isolated from salt-marshland soil and characterized for their physiological, molecular, and biochemical properties. Twenty-four bacterial isolates collected from high saline fields of salt marshland were analyzed by MALDI-TOF MS proteome analysis, which confirmed the taxonomic affiliation with Bacillus cereus, Bacillus subtilis, Bacillus atrophaeus, and Bacillus thorngiensis. Applying the isolates on maize plants as bio-inoculant bacteria obviously increased the growth parameters (P < 0.01). Pot experiments showed that isolates 74 and 90 were the most prominent strains to minimize the harmful effects of salinity. Its effects are heightening the potassium/sodium ratio and K-Na selectivity in shoots and roots measured by flame atomic absorption photometry (AAS). Accordingly, Bacillus cereus isolate 74 showed a maximum increase in dry weights of the shoot (133.89%), root (237.08%), length of the shoot (125%), and root (119.44%) compared to the control condition. Our findings suggest that bacteria isolated from marshland may be an economical and simple means to increase plant growth and resistance to high salinity soil conditions.


Assuntos
Bacillus , Zea mays , Bacillus/fisiologia , Bactérias , Raízes de Plantas , Salinidade , Estresse Salino , Solo/química , Microbiologia do Solo
7.
Blood Cells Mol Dis ; 92: 102596, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34547651

RESUMO

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe, recurrent bacterial and fungal infections. The disease is caused by mutations in the genes encoding the components of the leukocyte NADPH oxidase. This enzyme produces superoxide, which is subsequently metabolized to hydrogen peroxide and other reactive oxygen species (ROS). These products are essential for intracellular killing of pathogens by phagocytic leukocytes (neutrophils, eosinophils, monocytes and macrophages). The leukocyte NADPH oxidase is composed of five subunits, four of which are encoded by autosomal genes. These are CYBA, encoding p22phox, NCF1, encoding p47phox, NCF2, encoding p67phox and NCF4, encoding p40phox. This article lists all mutations identified in these genes in CGD patients. In addition, cytochrome b558 chaperone-1 (CYBC1), recently recognized as an essential chaperone protein for the expression of the X-linked NADPH oxidase component gp91phox (also called Nox2), is encoded by the autosomal gene CYBC1. Mutations in this gene also lead to CGD. Finally, RAC2, a small GTPase of the Rho family, is needed for activation of the NADPH oxidase, and mutations in the RAC2 gene therefore also induce CGD-like symptoms. Mutations in these last two genes are also listed in this article.


Assuntos
Doença Granulomatosa Crônica/genética , Mutação , Humanos , NADPH Oxidases/genética
8.
Blood Cells Mol Dis ; 90: 102587, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34175765

RESUMO

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe bacterial and fungal infections. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide and subsequently formed other reactive oxygen species (ROS) are instrumental in killing phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91phox, also called Nox2. This protein is encoded by the CYBB gene on the X chromosome. Mutations in this gene are found in about 70% of all CGD patients in Europe and in about 20% in countries with a high ratio of parental consanguinity. This article lists all mutations identified in CYBB and should therefore help in genetic counseling of X-CGD patients' families. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of disease-causing mutations. In addition, we also include some mutations in G6PD, the gene on the X chromosome that encodes glucose-6-phosphate dehydrogenase, because inactivity of this enzyme may lead to shortage of NADPH and thus to insufficient activity of NADPH oxidase. Severe G6PD deficiency can induce CGD-like symptoms.


Assuntos
Cromossomos Humanos X/genética , Doença Granulomatosa Crônica/genética , Mutação , NADPH Oxidase 2/genética , Humanos
9.
Rheumatology (Oxford) ; 60(11): 5436-5446, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33693560

RESUMO

OBJECTIVE: In 2016 specific heterozygous gain-of-function mutations in the Mediterranean fever gene MEFV were reported as causal for a distinct autoinflammatory disease coined pyrin-associated autoinflammation with neutrophilic dermatosis (PAAND). We sought to provide an extended report on clinical manifestations in PAAND patients to date and evaluate the efficacy and safety of treatment with the IL-1-blocking agent anakinra. METHODS: We undertook an open-label pilot study with anakinra. Three patients were recruited in a preliminary phase of the study with the intention to expand the treatment cohort in case of a favourable response. Acute-phase reactants and plasma cytokine levels were monitored throughout. Skin biopsies at baseline and at week 12 were stained for relevant cytokines. Available clinical data on treatment responses were retrospectively collected on additional patients. RESULTS: The three patients from the preliminary phase of the study [patients 1-3 (P1-P3)] demonstrated one failed and two partial treatment responses, where one patient opted to continue treatment with anakinra and the other favoured adalimumab. While a partial systemic response was observed, there was no appreciable effect of anakinra on the prominent cutaneous manifestations, reflected in residual local inflammatory cytokine expression in lesional skin. These observations did not warrant further expansion of the treatment cohort. Clinical data was retrospectively collected on an additional eight patients (P4-P11), highlighting both dominant and recessive inheritance with variable penetrance in PAAND and common gastrointestinal involvement that was not previously appreciated. CONCLUSION: In our experience, while anakinra appears safe, it was not superior to biologicals targeting TNF-α in PAAND despite evidence directly implicating dysregulated IL-1ß signalling.


Assuntos
Antirreumáticos/uso terapêutico , Doenças Hereditárias Autoinflamatórias/tratamento farmacológico , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Transtornos Leucocíticos/congênito , Dermatopatias Genéticas/tratamento farmacológico , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Transtornos Leucocíticos/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Fenótipo , Projetos Piloto , Pirina/genética
10.
Andrologia ; 53(7): e14080, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33966302

RESUMO

Primary ciliary dyskinesia (PCD) is a disorder of structure and function of motor ciliary and dyskinetic activity of ciliary in the fallopian tubes of affected women and could lead to infertility in some cases. In vitro fertilisation (IVF) is a choice of treatment in infertile women with PCD, which could conquer the tubal dysfunction. In this case study, we report a PCD affected woman with infertility who was treated by IVF and pregnancy was achieved but it failed due to the spontaneous abortion. We also performed whole-exome sequencing for this case and her PCD-affected sister, which did not reveal any genetic abnormality related to the PCD or infertility.


Assuntos
Transtornos da Motilidade Ciliar , Infertilidade Feminina , Tubas Uterinas , Feminino , Fertilização in vitro , Humanos , Infertilidade Feminina/terapia , Gravidez , Injeções de Esperma Intracitoplásmicas
11.
Ann Hum Genet ; 84(1): 102-106, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31571209

RESUMO

Osteosclerotic metaphyseal dysplasia (OSMD) is a very rare autosomal-recessive disorder and a distinctive type of osteopetrosis, characterized mainly by skeletal fractures and deformity, osteosclerosis, and sometimes hypotonia, developmental delay, and seizures. Sequence variants in the leucine-rich repeat kinase 1 (LRRK1) gene underlying OSMD have been reported previously. In the present study, we investigated a 14-year-old girl suspected with OSMD in a consanguineous family of Iranian origin segregating the disease in an autosomal-recessive manner. The patient had severe short stature, multiple sclerotic lesions, sandwich vertebrae, Erlenmeyer flask deformity, and looser zones. The multifocal active bony pathology suggested multifocal bony inflammation or multiple looser fractures. Whole-exome sequencing followed by Sanger sequencing confirmation revealed a novel homozygous stop gain mutation (c.G2785T, p.E929X) in the LRRK1 gene. This is the first mutation in the LRRK1 gene, underlying OSMD, in the Iranian population and the third case worldwide. The mutation is located in the C terminal of the Roc domain, distinct from domains affected in the previous two LRRK1 mutations. Additionally, a new group of clinical indications different from the two previous cases is discussed.


Assuntos
Mutação com Ganho de Função , Osteocondrodisplasias/genética , Osteosclerose/genética , Proteínas Serina-Treonina Quinases/genética , Adolescente , Sequência de Aminoácidos , Códon sem Sentido , Feminino , Humanos , Osteocondrodisplasias/patologia , Osteosclerose/patologia , Prognóstico , Homologia de Sequência
12.
Acta Microbiol Immunol Hung ; 67(1): 56-60, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31847541

RESUMO

Chronic granulomatous disease is a non-prevalent genetic disorder due to different structural gene mutations encoding components of nicotinamide adenine dinucleotide phosphate oxidase complex. Nicotinamide adenine dinucleotide phosphate oxidase is a complex made by a group of five proteins (subunit) and plays an important role in the innate immune system. Five structural genes are responsible for encoding each subunit, in which cytochrome b-245 alpha chain (also known as p22-phox) is encoded by CYBA gene. CYBA gene mutation leads to a group of autosomal dominant chronic granulomatous disease. Decreased level or lack of nicotinamide adenine dinucleotide phosphate oxidase leaves affected individuals vulnerable to many types of infections and excessive inflammation. In this study, a family affected by BCGitis caused by a novel intronic autosomal recessive CYBA mutation (88,713,158 C > T) has been described. The proband is a 5-year-old girl with chronic granulomatous disease who was referred to the clinic due to BCGitis. The culprit mutation was detected following whole genome sequencing and was confirmed among the family members by Sanger sequencing. Being symptom-free at the time of diagnosis, despite the proband's mother homozygosity, was a characteristic feature of this report. Remarkably, none of the CYBA-mutated members, as a known chronic granulomatous disease causing gene, has expressed symptoms other than regional lymph node enlargements. This might explain the gene mutation site importance in demonstrating different manifestations.


Assuntos
Família , Genes Recessivos , Doença Granulomatosa Crônica/diagnóstico , Doença Granulomatosa Crônica/genética , NADPH Oxidases/genética , Adulto , Criança , Pré-Escolar , Feminino , Testes Genéticos , Humanos , Linfonodos/patologia , Masculino , Mutação , Sequenciamento Completo do Genoma
15.
J Clin Immunol ; 37(8): 801-810, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28993958

RESUMO

Hypomorphic IKBKG mutations in males are typically associated with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID). Some mutations cause immunodeficiency without EDA (NEMO-ID). The immunological profile associated with these NEMO-ID variants is not fully documented. We present a 2-year-old patient with suspected immunodeficiency in which a hemizygous p.Glu57Lys IKBKG variant was identified. At the age of 1 year, he had an episode of otitis media that evolved into a bilateral mastoiditis (Pseudomonas spp). Hypogammaglobulinemia, specific (polysaccharide) antibody deficiency, and low switched memory B cell subsets were noticed. The mother was heterozygous for the variant but had no signs of incontinentia pigmenti. Patient peripheral blood mononuclear cells produced low amounts of IL-6 after stimulation with IL-1ß, Pam3CSK4, and FSL-1. In patient fibroblasts, IκB-α was degraded normally upon stimulation with IL-1ß or TNF-α. Transduction of wild-type and variant NEMO in NEMO-/- deficient SV40 fibroblasts revealed a slight but significant reduction of IL-6 production upon stimulation with IL-1ß and TNF-α. In conclusion, we demonstrated that p.Glu57Lys leads to specific immunological defects in vitro. No other pathogenic PID variants were identified through whole exome sequencing. As rare polymorphisms have been described in IKBKG and polygenic inheritance remains an option in the presented case, this study emphasizes the need for thorough functional and genetic evaluation when encountering and interpreting suspected disease-causing NEMO-ID variants.


Assuntos
Imunodeficiência de Variável Comum/genética , Displasia Ectodérmica/genética , Fibroblastos/fisiologia , Quinase I-kappa B/genética , Mutação/genética , Infecções por Pseudomonas/diagnóstico , Pseudomonas/fisiologia , Agamaglobulinemia , Células Cultivadas , Pré-Escolar , Imunodeficiência de Variável Comum/diagnóstico , Displasia Ectodérmica/diagnóstico , Hemizigoto , Humanos , Quinase I-kappa B/metabolismo , Interleucina-6/metabolismo , Masculino , Mastoidite , Otite , Polimorfismo Genético
16.
Immunol Invest ; 46(1): 70-79, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27759478

RESUMO

ZAP-70 deficiency is a rare autosomal recessive form of combined immunodeficiency (CID) characterized by selective absence of circulating CD8 T cells with low, normal, or increased CD4 T cells in peripheral blood. Up to now, 14 unique mutations in the ZAP70 gene have been identified in patients with ZAP-70-related CID. We present a 3-year-old boy with a history of recurrent bacterial infections and autoimmunity. Initial laboratory findings showed a normal total lymphocyte count, but low levels of CD8 and CD4 T cells and an abnormal lymphocyte proliferation response. Immunoglobulin levels were normal, but the specific antibody response was impaired. Whole exome sequencing revealed a mutation within the kinase domain of ZAP-70. ZAP-70 deficiency should be considered in infants and young children with recurrent bacterial infections, in spite of having palpable lymph nodes, a notable thymus shadow, and a normal total lymphocyte count.


Assuntos
Doenças Autoimunes/genética , Infecções Bacterianas/genética , Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Síndromes de Imunodeficiência/genética , Mutação/genética , Proteína-Tirosina Quinase ZAP-70/genética , Proliferação de Células/genética , Pré-Escolar , Análise Mutacional de DNA , Humanos , Imunidade Humoral/genética , Irã (Geográfico) , Masculino , Sistema de Registros
17.
Curr Microbiol ; 73(5): 611-617, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27460584

RESUMO

The polysaccharide intercellular adhesin (PIA) confers major functional effects in biofilm formation, which bears an important role in the pathogenicity of Staphylococcus epidermidis. Following the identification of biofilm-forming strains by biochemical and molecular methods, isogenic strain was prepared and in vitro biofilm formation assay was performed consequently. By parallel analysis of both the PIA-positive and PIA-negative strains using size exclusion chromatography by Fast protein liquid chromatography (FPLC) method, the respective PIA was purified. Recovered PIA was examined using colorimetric and hemagglutination assays. Finally, the recovered PIA was analyzed using Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy methods. By the parallel purification process and comparison of the obtained graphs from the FPLC detector, fractions near the void volume were determined as PIA. The colorimetric and hemagglutination assays were applied and the content of carbohydrates (hexose = 620 µg/ml, hexosamine = 5700 µg/ml and ketoses = 170 µg/ml) and hemagglutination titer (1:128) in recovered polysaccharide were determined. This study shows that PIA has a significant role in the biofilm formation in S. epidermidis strains. The recovered polysaccharide and its molecular weight were analyzed within the near void volume of the utilized column.


Assuntos
Adesinas Bacterianas/isolamento & purificação , Adesinas Bacterianas/metabolismo , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/metabolismo , Staphylococcus epidermidis/química , Adesinas Bacterianas/química , Adesinas Bacterianas/genética , Biofilmes , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/genética , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus epidermidis/genética , Staphylococcus epidermidis/fisiologia
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