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1.
Sci Rep ; 11(1): 13450, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34188129

RESUMO

Atherosclerosis has been considered as the main cause of morbidity, mortality, and disability worldwide. The first screening for antigen markers was conducted using the serological identification of antigens by recombinant cDNA expression cloning, which has identified adaptor-related protein complex 3 subunit delta 1 (AP3D1) as an antigen recognized by serum IgG antibodies of patients with atherosclerosis. Serum antibody levels were examined using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) using a recombinant protein as an antigen. It was determined that the serum antibody levels against AP3D1 were higher in patients with acute ischemic stroke (AIS), transient ischemic attack, diabetes mellitus (DM), cardiovascular disease, chronic kidney disease (CKD), esophageal squamous cell carcinoma (ESCC), and colorectal carcinoma than those in the healthy donors. The area under the curve values of DM, nephrosclerosis type of CKD, and ESCC calculated using receiver operating characteristic curve analysis were higher than those of other diseases. Correlation analysis showed that the anti-AP3D1 antibody levels were highly associated with maximum intima-media thickness, which indicates that this marker reflected the development of atherosclerosis. The results of the Japan Public Health Center-based Prospective Study indicated that this antibody marker is deemed useful as risk factors for AIS.


Assuntos
Complexo 3 de Proteínas Adaptadoras , Subunidades delta do Complexo de Proteínas Adaptadoras , Aterosclerose , Autoanticorpos , Imunoglobulina G , AVC Isquêmico , Complexo 3 de Proteínas Adaptadoras/sangue , Complexo 3 de Proteínas Adaptadoras/imunologia , Subunidades delta do Complexo de Proteínas Adaptadoras/sangue , Subunidades delta do Complexo de Proteínas Adaptadoras/imunologia , Idoso , Idoso de 80 Anos ou mais , Aterosclerose/sangue , Aterosclerose/complicações , Aterosclerose/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , AVC Isquêmico/sangue , AVC Isquêmico/etiologia , AVC Isquêmico/imunologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
2.
Front Immunol ; 10: 1449, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31293596

RESUMO

Adaptor proteins contribute to the selection, differentiation and activation of natural killer T (NKT) cells, an innate(-like) lymphocyte population endowed with powerful immunomodulatory properties. Distinct from conventional T lymphocytes NKT cells preferentially home to the liver, undergo a thymic maturation and differentiation process and recognize glycolipid antigens presented by the MHC class I-like molecule CD1d on antigen presenting cells. NKT cells express a semi-invariant T cell receptor (TCR), which combines the Vα14-Jα18 chain with a Vß2, Vß7, or Vß8 chain in mice and the Vα24 chain with the Vß11 chain in humans. The avidity of interactions between their TCR, the presented glycolipid antigen and CD1d govern the selection and differentiation of NKT cells. Compared to TCR ligation on conventional T cells engagement of the NKT cell TCR delivers substantially stronger signals, which trigger the unique NKT cell developmental program. Furthermore, NKT cells express a panoply of primarily inhibitory NK cell receptors (NKRs) that control their self-reactivity and avoid autoimmune activation. Adaptor proteins influence NKT cell biology through the integration of TCR, NKR and/or SLAM (signaling lymphocyte-activation molecule) receptor signals or the variation of CD1d-restricted antigen presentation. TCR and NKR ligation engage the SH2 domain-containing leukocyte protein of 76kDa slp-76 whereas the SLAM associated protein SAP serves as adaptor for the SLAM receptor family. Indeed, the selection and differentiation of NKT cells selectively requires co-stimulation via SLAM receptors. Furthermore, SAP deficiency causes X-linked lymphoproliferative disease with multiple immune defects including a lack of circulating NKT cells. While a deletion of slp-76 leads to a complete loss of all peripheral T cell populations, mutations in the SH2 domain of slp-76 selectively affect NKT cell biology. Furthermore, adaptor proteins influence the expression and trafficking of CD1d in antigen presenting cells and subsequently selection and activation of NKT cells. Adaptor protein complex 3 (AP-3), for example, is required for the efficient presentation of glycolipid antigens which require internalization and processing. Thus, our review will focus on the complex contribution of adaptor proteins to the delivery of TCR, NKR and SLAM receptor signals in the unique biology of NKT cells and CD1d-restricted antigen presentation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Antígenos CD1d/imunologia , Células T Matadoras Naturais/imunologia , Fosfoproteínas/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Células Matadoras Naturais/imunologia , Família de Moléculas de Sinalização da Ativação Linfocitária/imunologia , Complexo 3 de Proteínas Adaptadoras/imunologia , Complexo 3 de Proteínas Adaptadoras/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apresentação de Antígeno/imunologia , Antígenos CD1d/metabolismo , Humanos , Ativação Linfocitária/imunologia , Camundongos , Células T Matadoras Naturais/metabolismo , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Células Matadoras Naturais/metabolismo , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo
3.
EMBO J ; 37(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30131424

RESUMO

Plasmacytoid dendritic cells (pDC) are the major source of type I interferons (IFN-I) during viral infections, in response to triggering of endosomal Toll-like receptors (TLRs) 7 or 9 by viral single-stranded RNA or unmethylated CpG DNA, respectively. Synthetic ligands have been used to disentangle the underlying signaling pathways. The adaptor protein AP3 is necessary to transport molecular complexes of TLRs, synthetic CpG DNA, and MyD88 into endosomal compartments allowing interferon regulatory factor 7 (IRF7) recruitment whose phosphorylation then initiates IFN-I production. High basal expression of IRF7 by pDC and its further enhancement by positive IFN-I feedback signaling appear to be necessary for robust cytokine production. In contrast, we show here that in vivo during mouse cytomegalovirus (MCMV) infection pDC produce high amounts of IFN-I downstream of the TLR9-to-MyD88-to-IRF7 signaling pathway without requiring IFN-I positive feedback, high IRF7 expression, or AP3-driven endosomal routing of TLRs. Hence, the current model of the molecular requirements for professional IFN-I production by pDC, established by using synthetic TLR ligands, does not strictly apply to a physiological viral infection.


Assuntos
Células Dendríticas/imunologia , Infecções por Herpesviridae/imunologia , Interferon Tipo I/imunologia , Muromegalovirus/imunologia , Transdução de Sinais/imunologia , Complexo 3 de Proteínas Adaptadoras/genética , Complexo 3 de Proteínas Adaptadoras/imunologia , Animais , Células Dendríticas/patologia , Endossomos/genética , Endossomos/imunologia , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/patologia , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/imunologia , Interferon Tipo I/genética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Transdução de Sinais/genética , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/imunologia , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/imunologia
4.
PLoS Pathog ; 13(12): e1006785, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29253868

RESUMO

Bacterial pathogens that compromise phagosomal membranes stimulate inflammasome assembly in the cytosol, but the molecular mechanisms by which membrane dynamics regulate inflammasome activity are poorly characterized. We show that in murine dendritic cells (DCs), the endosomal adaptor protein AP-3 -which optimizes toll-like receptor signaling from phagosomes-sustains inflammasome activation by particulate stimuli. AP-3 independently regulates inflammasome positioning and autophagy induction, together resulting in delayed inflammasome inactivation by autophagy in response to Salmonella Typhimurium (STm) and other particulate stimuli specifically in DCs. AP-3-deficient DCs, but not macrophages, hyposecrete IL-1ß and IL-18 in response to particulate stimuli in vitro, but caspase-1 and IL-1ß levels are restored by silencing autophagy. Concomitantly, AP-3-deficient mice exhibit higher mortality and produce less IL-1ß, IL-18, and IL-17 than controls upon oral STm infection. Our data identify a novel link between phagocytosis, inflammasome activity and autophagy in DCs, potentially explaining impaired antibacterial immunity in AP-3-deficient patients.


Assuntos
Complexo 3 de Proteínas Adaptadoras/deficiência , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Inflamassomos/imunologia , Imunidade Adaptativa , Complexo 3 de Proteínas Adaptadoras/genética , Complexo 3 de Proteínas Adaptadoras/imunologia , Animais , Autofagia/imunologia , Células Dendríticas/patologia , Feminino , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Interleucina-17/biossíntese , Interleucina-18/biossíntese , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas NLR/genética , Proteínas NLR/imunologia , Fagocitose , Salmonelose Animal/imunologia , Salmonelose Animal/patologia , Salmonella typhimurium/imunologia , Salmonella typhimurium/patogenicidade , Ativação Transcricional
5.
Blood ; 127(26): 3382-6, 2016 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-27207797

RESUMO

Hermansky-Pudlak syndrome type 2 (HPS2) is a primary immunodeficiency due to adaptor protein-3 (AP-3) complex deficiency. HPS2 patients present neutropenia, partial albinism, and impaired lysosomal vesicles formation in hematopoietic cells. Given the role of dendritic cells (DCs) in the immune response, we studied monocyte-derived DCs (moDCs) and plasmacytoid DCs (pDCs) in two HPS2 siblings. Mature HPS2 moDCs showed impaired expression of CD83 and DC-lysosome-associated membrane protein (LAMP), low levels of MIP1-ß/CCL4, MIG/CXCL9, and severe defect of interleukin-12 (IL-12) secretion. DCs in lymph-node biopsies from the same patients showed a diffuse cytoplasm reactivity in a large fraction of DC-LAMP(+) cells, instead of the classical dot-like stain. In addition, analysis of pDC-related functions of blood-circulating mononuclear cells revealed reduced interferon-α secretion in response to herpes simplex virus-1 (HSV-1), whereas granzyme-B induction upon IL-3/IL-10 stimulation was normal. Finally, T-cell costimulatory activity, as measured by mixed lymphocyte reaction assay, was lower in patients, suggesting that function and maturation of DCs is abnormal in patients with HPS2.


Assuntos
Complexo 3 de Proteínas Adaptadoras/deficiência , Células Dendríticas/imunologia , Regulação da Expressão Gênica/imunologia , Síndrome de Hermanski-Pudlak/imunologia , Monócitos/imunologia , Complexo 3 de Proteínas Adaptadoras/imunologia , Antígenos CD/genética , Antígenos CD/imunologia , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/imunologia , Citocinas/genética , Citocinas/imunologia , Células Dendríticas/patologia , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Granzimas/genética , Granzimas/imunologia , Síndrome de Hermanski-Pudlak/genética , Síndrome de Hermanski-Pudlak/patologia , Herpesvirus Humano 1/imunologia , Humanos , Imunoglobulinas/genética , Imunoglobulinas/imunologia , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Monócitos/patologia , Linfócitos T/imunologia , Linfócitos T/patologia , Antígeno CD83
6.
J Immunol ; 195(9): 4331-40, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26423153

RESUMO

Innate immune engagement results in the activation of host defenses that produce microbe-specific inflammatory responses. A long-standing interest in the field of innate immunity is to understand how varied host responses are generated through the signaling of just a limited number of receptors. Recently, intracellular trafficking and compartmental partitioning have been identified as mechanisms that provide signaling specificity for receptors by regulating signaling platform assembly. We show that cytokine activation as a result of TLR2 stimulation occurs at different intracellular locations and is mediated by the phagosomal trafficking molecule adaptor protein-3 (AP-3). AP-3 is required for trafficking TLR2 purified ligands or the Lyme disease causing bacterium, Borrelia burgdorferi, to LAMP-1 lysosomal compartments. The presence of AP-3 is necessary for the activation of cytokines such as IL-6 but not TNF-α or type I IFNs, suggesting induction of these cytokines occurs from a different compartment. Lack of AP-3 does not interfere with the recruitment of TLR signaling adaptors TRAM and MyD88 to the phagosome, indicating that the TLR-MyD88 signaling complex is assembled at a prelysosomal stage and that IL-6 activation depends on proper localization of signaling molecules downstream of MyD88. Finally, infection of AP-3-deficient mice with B. burgdorferi resulted in altered joint inflammation during murine Lyme arthritis. Our studies further elucidate the effects of phagosomal trafficking on tailoring immune responses in vitro and in vivo.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Citocinas/imunologia , Mediadores da Inflamação/imunologia , Receptor 2 Toll-Like/imunologia , Complexo 3 de Proteínas Adaptadoras/genética , Complexo 3 de Proteínas Adaptadoras/metabolismo , Animais , Borrelia burgdorferi/imunologia , Borrelia burgdorferi/metabolismo , Borrelia burgdorferi/fisiologia , Células Cultivadas , Citocinas/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Mediadores da Inflamação/metabolismo , Células L , Lipopeptídeos/imunologia , Lipopeptídeos/metabolismo , Lipopeptídeos/farmacologia , Lisossomos/imunologia , Lisossomos/metabolismo , Lisossomos/microbiologia , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Fagossomos/imunologia , Fagossomos/metabolismo , Fagossomos/microbiologia , Transporte Proteico/imunologia , Receptores de Interleucina/genética , Receptores de Interleucina/imunologia , Receptores de Interleucina/metabolismo , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/imunologia , Receptores de Interleucina-1/metabolismo , Receptor 2 Toll-Like/agonistas , Receptor 2 Toll-Like/metabolismo
7.
J Neuroinflammation ; 12: 168, 2015 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-26377319

RESUMO

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Subunidades beta do Complexo de Proteínas Adaptadoras/imunologia , Autoanticorpos/metabolismo , Ataxia Cerebelar , Proteínas do Tecido Nervoso/imunologia , Receptores de Superfície Celular/imunologia , Ataxia Cerebelar/diagnóstico , Ataxia Cerebelar/imunologia , Ataxia Cerebelar/metabolismo , Humanos , Células de Purkinje
8.
Blood ; 121(15): 2943-51, 2013 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-23403622

RESUMO

Genetic disorders of lymphocyte cytotoxicity predispose patients to hemophagocytic lymphohistiocytosis (HLH). Reduced lymphocyte cytotoxicity has been demonstrated in Hermansky-Pudlak syndrome type 2 (HPS2), but only a single patient was reported who developed HLH. Because that patient also carried a potentially contributing heterozygous RAB27A mutation, the risk for HLH in HPS2 remains unclear. We analyzed susceptibility to HLH in the pearl mouse model of HPS2. After infection with lymphocytic choriomeningitis virus, pearl mice developed all key features of HLH, linked to impaired virus control caused by a moderate defect in CTL cytotoxicity in vivo. However, in contrast to perforin-deficient mice, the disease was transient, and all mice fully recovered and controlled the infection. An additional heterozygous Rab27a mutation did not aggravate the cytotoxicity defect or disease parameters. In the largest survey of 22 HPS2 patients covering 234 patient years, we identified only 1 additional patient with HLH and 2 with incomplete transient HLH-like episodes, although cytotoxicity or degranulation was impaired in all 16 patients tested. HPS2 confers a risk for HLH that is lower than in Griscelli or Chediak-Higashi syndrome, probably because of a milder defect in cytotoxicity. Preemptive hematopoietic stem cell transplantation does not appear justified in HPS2.


Assuntos
Citotoxicidade Imunológica/imunologia , Síndrome de Hermanski-Pudlak/imunologia , Linfo-Histiocitose Hemofagocítica/imunologia , Linfócitos T Citotóxicos/imunologia , Complexo 3 de Proteínas Adaptadoras/deficiência , Complexo 3 de Proteínas Adaptadoras/genética , Complexo 3 de Proteínas Adaptadoras/imunologia , Subunidades beta do Complexo de Proteínas Adaptadoras/deficiência , Subunidades beta do Complexo de Proteínas Adaptadoras/genética , Subunidades beta do Complexo de Proteínas Adaptadoras/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Citotoxicidade Imunológica/genética , Citometria de Fluxo , Síndrome de Hermanski-Pudlak/complicações , Síndrome de Hermanski-Pudlak/genética , Humanos , Linfo-Histiocitose Hemofagocítica/etiologia , Linfo-Histiocitose Hemofagocítica/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Fatores de Risco , Linfócitos T Citotóxicos/metabolismo , Adulto Jovem , Proteínas rab de Ligação ao GTP/deficiência , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/imunologia , Proteínas rab27 de Ligação ao GTP
9.
Immunity ; 36(5): 782-94, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-22560444

RESUMO

Effective major histocompatibility complex-II (MHC-II) antigen presentation from phagocytosed particles requires phagosome-intrinsic Toll-like receptor (TLR) signaling, but the molecular mechanisms underlying TLR delivery to phagosomes and how signaling regulates antigen presentation are incompletely understood. We show a requirement in dendritic cells (DCs) for adaptor protein-3 (AP-3) in efficient TLR recruitment to phagosomes and MHC-II presentation of antigens internalized by phagocytosis but not receptor-mediated endocytosis. DCs from AP-3-deficient pearl mice elicited impaired CD4(+) T cell activation and Th1 effector cell function to particulate antigen in vitro and to recombinant Listeria monocytogenes infection in vivo. Whereas phagolysosome maturation and peptide:MHC-II complex assembly proceeded normally in pearl DCs, peptide:MHC-II export to the cell surface was impeded. This correlated with reduced TLR4 recruitment and proinflammatory signaling from phagosomes by particulate TLR ligands. We propose that AP-3-dependent TLR delivery from endosomes to phagosomes and subsequent signaling mobilize peptide:MHC-II export from intracellular stores.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , Fagossomos/imunologia , Receptores Toll-Like/imunologia , Complexo 3 de Proteínas Adaptadoras/metabolismo , Animais , Antígenos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/imunologia , Membrana Celular/imunologia , Membrana Celular/metabolismo , Células Cultivadas , Células Dendríticas/metabolismo , Endocitose/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Ligantes , Listeria monocytogenes/imunologia , Listeriose/imunologia , Listeriose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fator 88 de Diferenciação Mieloide/imunologia , Fator 88 de Diferenciação Mieloide/metabolismo , Ovalbumina/imunologia , Ovalbumina/metabolismo , Peptídeos/imunologia , Peptídeos/metabolismo , Fagocitose/imunologia , Fagossomos/metabolismo , Transdução de Sinais/imunologia , Células Th1/imunologia , Células Th1/metabolismo , Receptores Toll-Like/metabolismo
10.
Mol Genet Metab ; 93(2): 134-44, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17933573

RESUMO

Hermansky-Pudlak syndrome (HPS) comprises a constellation of human autosomal recessive disorders characterized by albinism and platelet storage pool deficiency. At least eight types of HPS have been defined based on the identity of the mutated gene. These genes encode components of four ubiquitously expressed protein complexes, named Adaptor Protein (AP)-3 and Biogenesis of Lysosome-related Organelles Complex (BLOC)-1 through -3. In patients of Puerto Rican origin, the molecular diagnosis can be based on analysis of two founder mutations. On the other hand, identification of the HPS type in other patients relies on the sequencing of all candidate genes. In this work, we have developed a biochemical assay to minimize the number of candidate genes to be sequenced per patient. The assay consists of immunoblotting analysis of extracts prepared from skin fibroblasts, using antibodies to one subunit per protein complex. The assay allowed us to determine which complex was defective in each of a group of HPS patients with unknown genetic lesions, thus subsequent sequencing was limited to genes encoding the corresponding subunits. Because no mutations within the two genes encoding BLOC-3 subunits could be found in two patients displaying reduced BLOC-3 levels, the possible existence of additional subunits was considered. Through size-exclusion chromatography and sedimentation velocity analysis, the native molecular mass of BLOC-3 was estimated to be 140+/-30 kDa, a value most consistent with the idea that BLOC-3 is a HPS1HPS4 heterodimer (approximately 156 kDa) albeit not inconsistent with the putative existence of a relatively small third subunit.


Assuntos
Western Blotting/métodos , Síndrome de Hermanski-Pudlak/diagnóstico , Síndrome de Hermanski-Pudlak/genética , Complexo 3 de Proteínas Adaptadoras/genética , Complexo 3 de Proteínas Adaptadoras/imunologia , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Sequência de Bases , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , DNA/genética , Síndrome de Hermanski-Pudlak/classificação , Humanos , Camundongos , Dados de Sequência Molecular , Peso Molecular , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Proteínas/genética , Proteínas/imunologia , Homologia de Sequência de Aminoácidos
11.
Blood ; 107(12): 4857-64, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16507770

RESUMO

Adaptor protein-3 (AP-3) is an ubiquitous cytoplasmic complex that shuttles cargo proteins from the trans-Golgi and a tubular-endosomal compartment to endosome-lysosome-related organelles. Lack of the beta3A subunit of this complex causes Hermansky-Pudlak syndrome type 2, an autosomal recessive disease characterized by partial albinism, prolonged bleeding tendency, and immunodeficiency. To investigate the pathogenesis of immunodeficiency, we studied natural killer (NK) cells and neutrophil functions in 2 previously unreported siblings affected by Hermansky-Pudlak type 2 syndrome. In both patients we observed a dramatic reduction of cytolytic activity of freshly isolated and of IL-2-activated NK cells. Levels of perforin were reduced in unstimulated NK cells, thereby accounting for the impairment of NK cytolitic activity. In addition, analysis of neutrophils in these patients demonstrated that intracellular elastase content was largely reduced while CD63 expression on plasma membrane was substantially increased. Taken together, these observations suggest that type 2 Hermansky-Pudlak syndrome is characterized by defects of innate immunity.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Subunidades beta do Complexo de Proteínas Adaptadoras/imunologia , Antígenos CD/imunologia , Síndrome de Hermanski-Pudlak/imunologia , Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , Neutrófilos/imunologia , Glicoproteínas da Membrana de Plaquetas/imunologia , Adulto , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica/imunologia , Síndrome de Hermanski-Pudlak/patologia , Humanos , Imunidade Celular/imunologia , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/patologia , Lactente , Células Matadoras Naturais/patologia , Elastase de Leucócito/imunologia , Masculino , Neutrófilos/patologia , Tetraspanina 30 , Rede trans-Golgi/imunologia
12.
J Exp Med ; 198(8): 1133-46, 2003 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-14557411

RESUMO

Relatively little is known about the pathway leading to the presentation of glycolipids by CD1 molecules. Here we show that the adaptor protein complex 3 (AP-3) is required for the efficient presentation of glycolipid antigens that require internalization and processing. AP-3 interacts with mouse CD1d, and cells from mice deficient for AP-3 have increased cell surface levels of CD1d and decreased expression in late endosomes. Spleen cells from AP-3-deficient mice have a reduced ability to present glycolipids to natural killer T (NKT) cells. Furthermore, AP-3-deficient mice have a significantly reduced NKT cell population, although this is not caused by self-tolerance that might result from increased CD1d surface levels. These data suggest that the generation of the endogenous ligand that selects NKT cells may also be AP-3 dependent. However, the function of MHC class II-reactive CD4+ T lymphocytes is not altered by AP-3 deficiency. Consistent with this divergence from the class II pathway, NKT cell development and antigen presentation by CD1d are not reduced by invariant chain deficiency. These data demonstrate that the AP-3 requirement is a particular attribute of the CD1d pathway in mice and that, although MHC class II molecules and CD1d are both found in late endosomes or lysosomes, different pathways mediate their intracellular trafficking.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Antígenos CD1/imunologia , Glicoesfingolipídeos/imunologia , Células Matadoras Naturais/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Antígenos CD1/genética , Antígenos CD1d , Linfócitos T CD4-Positivos/imunologia , Contagem de Células , Regiões Determinantes de Complementaridade/química , Citometria de Fluxo , Fígado/imunologia , Lisossomos/metabolismo , Camundongos , Camundongos Mutantes , Proteínas Recombinantes de Fusão/imunologia , Subpopulações de Linfócitos T/química , Timo/imunologia
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