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1.
Front Immunol ; 12: 648754, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33790913

RESUMO

Background and Aims: Emerging evidence has revealed that innate lymphoid cells (ILCs) play a key role in regulating metabolic disorders. Here, we investigated the role of group 3 ILCs (ILC3s) in the modulation of Non-alcoholic fatty liver disease (NAFLD). Methods: RORγ gfp/gfp (RORgt KI/KI) and Rag2-/- mice with the administration of A213, RORgt antagonist, fed with a high-fat-diet (HFD) for 12 weeks, were used. We performed flow cytometry, real time PCR, and lipidomics analysis of serum and liver, and used RAW264.7 cells and murine primary hepatocytes in vitro. Results: HFD increased ILC3s and M1 macrophages in the liver, and RORgt KI/KI mice deficient in ILC3 showed significant fatty liver, liver fibrosis and significantly increased palmitic acid levels in serum and liver. In addition, administration of A213 to Rag2-/- mice caused significant fatty liver, liver fibrosis, and a significant increase in serum and liver palmitate concentrations, as in RORgt KI/KI mice. Addition of palmitc acid stimulated IL-23 production in cell experiments using RAW264.7. IL-22 produced by ILC3s inhibited the palmitate-induced apoptosis of primary hepatocytes. Conclusions: HFD stimulates IL-23 production by M1 macrophages, thus promoting ILC3 proliferation, whereas IL-22 secreted by ILC3s contributes to the upregulation of hepatic lipid metabolism and has anti-apoptosis activity.


Assuntos
Fígado Gorduroso/imunologia , Imunidade Inata/imunologia , Fígado/imunologia , Linfócitos/imunologia , Macrófagos/imunologia , Animais , Apoptose/imunologia , Células Cultivadas , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Hepatócitos/citologia , Hepatócitos/imunologia , Fígado/metabolismo , Fígado/patologia , Linfócitos/metabolismo , Macrófagos/classificação , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ácido Palmítico/sangue , Ácido Palmítico/imunologia , Ácido Palmítico/metabolismo , Substâncias Protetoras/metabolismo , Células RAW 264.7
2.
FEBS J ; 288(24): 7043-7059, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33506611

RESUMO

Protein cysteine palmitoylation, or S-palmitoylation, has been known for about 40 years, and thousands of proteins in humans are known to be modified. Because of the large number of proteins modified, the importance and physiological functions of S-palmitoylation are enormous. However, most of the known physiological functions of S-palmitoylation can be broadly classified into two categories, neurological or immunological. This review provides a summary on the function of S-palmitoylation from the immunological perspective. Several important immune signaling pathways are discussed, including STING, NOD1/2, JAK-STAT in cytokine signaling, T-cell receptor signaling, chemotactic GPCR signaling, apoptosis, phagocytosis, and endothelial and epithelial integrity. This review is not meant to be comprehensive, but rather focuses on specific examples to highlight the versatility of palmitoylation in regulating immune signaling, as well as the potential and challenges of targeting palmitoylation to treat immune diseases.


Assuntos
Cisteína/imunologia , Citocinas/imunologia , Inflamação/imunologia , Ácido Palmítico/imunologia , Animais , Humanos , Transdução de Sinais/imunologia
3.
Biochem Biophys Res Commun ; 513(1): 201-206, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-30952426

RESUMO

Elevated saturated free fatty acid levels during over-nutrition lead to hypothalamic inflammation, which perturbs energy homeostasis. Whether brain-derived metabolites are coupled to the development of obesity pathogenesis during the early over-nutrition period has not been thoroughly investigated. In this study, we found increased linoleic acid, an unsaturated fatty acid, in both the whole brain and hypothalamus of mice fed a high-fat diet for 4 weeks. Furthermore, we observed that linoleic acid effectively reversed the inflammatory responses induced by palmitic acid treatment in microglial cells. Collectively, this study suggests the reversible function of linoleic acid on brain inflammation in association with microglial activation during short-term exposure to a high-fat diet.


Assuntos
Anti-Inflamatórios/uso terapêutico , Dieta Hiperlipídica/efeitos adversos , Encefalite/tratamento farmacológico , Ácido Linoleico/uso terapêutico , Microglia/efeitos dos fármacos , Animais , Anti-Inflamatórios/imunologia , Encefalite/etiologia , Encefalite/imunologia , Ácido Linoleico/imunologia , Camundongos Endogâmicos C57BL , Microglia/imunologia , Ácido Palmítico/efeitos adversos , Ácido Palmítico/imunologia
4.
Mediators Inflamm ; 2015: 196297, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26633920

RESUMO

High levels of serum long chain saturated fatty acids (LCSFAs) have been associated with inflammation in type 2 diabetes. Dietary SFAs can promote inflammation, the secretion of IgG antibodies, and secretion of the proinflammatory cytokine IL-1ß. This study characterizes anti-LCSFA IgG antibodies from patients with type 2 diabetes. Serum samples from several cohorts with type 2 diabetes were analyzed for the presence of anti-LCSFA IgG, the cytokine IL-1ß, and nonesterified fatty acids. Anti-LCSFA IgG was isolated from patient samples and used for in vitro characterization of avidity and specificity. A cohort participating in En Balance, a diabetes health education program that improved diabetes management, tested positive for anti-LCSFA IgG. Following the 3-month program, the cohort showed a significant reduction in anti-LCSFA IgG levels. Anti-LCSFA antibodies isolated from these patients demonstrated high avidity, were specific for long chain SFAs, and correlated with serum fatty acids in patients with managed type 2 diabetes. Interestingly, anti-LCSFA IgG neutralized PA-induced IL-1ß secretion by dendritic cells. Our data shows that nonesterified SFAs are recognized by IgG antibodies present in human blood. The identification of anti-LCSFA IgG antibodies in human sera establishes a basis for further exploration of lipid induced immune responses in diabetic patients.


Assuntos
Diabetes Mellitus Tipo 2/imunologia , Ácidos Graxos/imunologia , Imunoglobulina G/sangue , Adulto , Idoso , Especificidade de Anticorpos , Células Dendríticas/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Interleucina-1beta/sangue , Masculino , Pessoa de Meia-Idade , Ácido Palmítico/imunologia
5.
Hum Vaccin Immunother ; 10(11): 3241-50, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25483652

RESUMO

It has been reported that lipopeptides can be used to elicit cytotoxic T lymphocyte (CTL) responses against viral diseases and cancer. In our previous study, we determined that mono-palmitoylated peptides can enhance anti-tumor responses in the absence of adjuvant activity. To investigate whether di-palmitoylated peptides with TLR2 agonist activity are able to induce anti-tumor immunity, we synthesized a di-palmitic acid-conjugated long peptide that contains a murine CTL epitope of HPV E749-57 (Pam2IDG). Pam2IDG stimulated the maturation of bone marrow-derived dendritic cells (BMDCs) through TLR2/6. After immunization, Pam2IDG induced higher levels of T cell responses than those obtained with its non-lipidated counterpart (IDG). In the prophylactic model, Pam2IDG immunization completely inhibited tumor growth, whereas IDG immunization was unable to inhibit tumor growth. However, Pam2IDG immunization could not effectively inhibit the growth of established tumors. Therefore, we further investigated whether the depletion of immunosuppressive factors could improve the therapeutic effects of Pam2IDG. Our data indicate that treatment with Pam2IDG combined with clodronate/liposome delays tumor growth and increases the survival rate. We also observed that the therapeutic effects of Pam2IDG are improved by diminishing the function of tumor-associate macrophages (TAMs) and through the use of an IL10 receptor blocking antibody or a Cyclooxygenase 2 (Cox-2) inhibitor. In conclusion, the depletion of TAMs may enhance the anti-tumor immunity of a TLR2 agonist-conjugated peptide.


Assuntos
Lipopeptídeos/uso terapêutico , Macrófagos/imunologia , Neoplasias/imunologia , Linfócitos T Citotóxicos/imunologia , Receptor 2 Toll-Like/agonistas , Animais , Anticorpos Bloqueadores/imunologia , Anticorpos Bloqueadores/uso terapêutico , Ácido Clodrônico/uso terapêutico , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Células Dendríticas/imunologia , Imunização , Imunoterapia , Lipopeptídeos/imunologia , Lipoilação , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/terapia , Ácido Palmítico/química , Ácido Palmítico/imunologia , Proteínas E7 de Papillomavirus/química , Proteínas E7 de Papillomavirus/imunologia , Receptores de Interleucina-10/antagonistas & inibidores , Receptores de Interleucina-10/imunologia , Taxa de Sobrevida , Receptor 2 Toll-Like/imunologia , Receptor 6 Toll-Like/imunologia
6.
J Immunol ; 193(4): 1666-71, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25031459

RESUMO

Enhancement of intestinal IgA responses is a primary strategy in the development of oral vaccine. Dietary fatty acids are known to regulate host immune responses. In this study, we show that dietary palmitic acid (PA) and its metabolites enhance intestinal IgA responses. Intestinal IgA production was increased in mice maintained on a PA-enriched diet. These mice also showed increased intestinal IgA responses against orally immunized Ag, without any effect on serum Ab responses. We found that PA directly stimulates plasma cells to produce Ab. In addition, mice receiving a PA-enriched diet had increased numbers of IgA-producing plasma cells in the large intestine; this effect was abolished when serine palmitoyltransferase was inhibited. These findings suggest that dietary PA regulates intestinal IgA responses and has the potential to be a diet-derived mucosal adjuvant.


Assuntos
Gorduras na Dieta/metabolismo , Imunoglobulina A/imunologia , Mucosa Intestinal/imunologia , Ácido Palmítico/imunologia , Adjuvantes Imunológicos/metabolismo , Animais , Células Cultivadas , Toxina da Cólera/imunologia , Óleo de Coco , Suplementos Nutricionais , Ácidos Graxos Monoinsaturados , Feminino , Imunidade nas Mucosas , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Ovalbumina/imunologia , Óleo de Palmeira , Ácido Palmítico/administração & dosagem , Óleos de Plantas/administração & dosagem , Óleos de Plantas/metabolismo , Plasmócitos/imunologia , Óleo de Brassica napus , Serina C-Palmitoiltransferase/antagonistas & inibidores , Óleo de Soja/administração & dosagem
7.
J Affect Disord ; 135(1-3): 414-8, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21930301

RESUMO

BACKGROUND: There is evidence that depression is accompanied by oxidative and nitrosative stress (O&NS), as indicated by increased free radical levels, lipid peroxidation, and lowered antioxidant levels. The aims of the present study are to examine whether depression is accompanied by autoimmune responses directed against a) neoepitopes that are formed following O&NS damage; and b) the major anchorage molecules, i.e. palmitic and myristic acids and S-farnesyl-L-cysteine. METHODS: We examined serum IgM antibodies to the conjugated fatty acids, palmitic and myristic acids; acetylcholine; S-farnesyl-L-cysteine; and NO-modified adducts in 26 depressed patients and 17 normal controls. Severity of depression was measured with the Hamilton Depression Rating Scale and severity of fatigue and somatic (F&S) symptoms with the Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale. RESULTS: The prevalences and mean values for the serum IgM levels directed against conjugated palmitic and myristic acids, acetylcholine, S-farnesyl-L-cysteine; and the conjugated NO adducts, NO-tyrosine, NO-phenylalanine, NO-aspartate, NO-histidine, and NO-creatine were significantly higher in depressed patients than in normal controls. The autoimmune responses were significantly related to FF symptoms, such as fatigue and a flu-like malaise, whereas the indicants of nitrosative stress were related to gastro-intestinal and autonomic symptoms. DISCUSSION: Depression is characterized by IgM-related autoimmune responses directed against a) neoepitopes that are normally not detected by the immune system but that due to damage by O&NS have become immunogenic; and b) anchorage epitopes, i.e. palmitic and myristic acids, and S-farnesyl-L-cysteine. These autoimmune responses play a role in the inflammatory and O&NS pathophysiology of depression and may mediate the cellular dysfunctions that contribute to neuroprogression, e.g. aberrations in signal transduction, cellular differentiation and apoptosis.


Assuntos
Autoimunidade/imunologia , Depressão/imunologia , Ácidos Graxos/imunologia , Imunoglobulina M/imunologia , Inflamação/imunologia , Acetilcolina/imunologia , Acetilcolina/metabolismo , Adulto , Idoso , Formação de Anticorpos/imunologia , Estudos de Casos e Controles , Cisteína/análogos & derivados , Cisteína/imunologia , Cisteína/metabolismo , Dano ao DNA , Transtorno Depressivo/complicações , Transtorno Depressivo/imunologia , Epitopos , Fadiga/sangue , Fadiga/complicações , Fadiga/imunologia , Ácidos Graxos/metabolismo , Feminino , Humanos , Imunoglobulina M/sangue , Peroxidação de Lipídeos/imunologia , Masculino , Pessoa de Meia-Idade , Ácido Mirístico/imunologia , Ácido Mirístico/metabolismo , Negociação , Óxido Nítrico , Estresse Oxidativo/imunologia , Estresse Oxidativo/fisiologia , Ácido Palmítico/imunologia , Ácido Palmítico/metabolismo , Índice de Gravidade de Doença
8.
Nat Immunol ; 12(5): 408-15, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21478880

RESUMO

High-fat diet (HFD) and inflammation are key contributors to insulin resistance and type 2 diabetes (T2D). Interleukin (IL)-1ß plays a role in insulin resistance, yet how IL-1ß is induced by the fatty acids in an HFD, and how this alters insulin signaling, is unclear. We show that the saturated fatty acid palmitate, but not unsaturated oleate, induces the activation of the NLRP3-ASC inflammasome, causing caspase-1, IL-1ß and IL-18 production. This pathway involves mitochondrial reactive oxygen species and the AMP-activated protein kinase and unc-51-like kinase-1 (ULK1) autophagy signaling cascade. Inflammasome activation in hematopoietic cells impairs insulin signaling in several target tissues to reduce glucose tolerance and insulin sensitivity. Furthermore, IL-1ß affects insulin sensitivity through tumor necrosis factor-independent and dependent pathways. These findings provide insights into the association of inflammation, diet and T2D.


Assuntos
Proteínas de Transporte/imunologia , Gorduras na Dieta/imunologia , Inflamassomos/imunologia , Resistência à Insulina/imunologia , Ácido Palmítico/imunologia , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Autofagia/imunologia , Caspase 1/imunologia , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Citometria de Fluxo , Interleucina-1beta/imunologia , Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Proteína 3 que Contém Domínio de Pirina da Família NLR , Oligopeptídeos/farmacologia , Espécies Reativas de Oxigênio/imunologia , Ribonucleotídeos/farmacologia , Transdução de Sinais
9.
J Invest Dermatol ; 130(4): 985-94, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20032992

RESUMO

Various sebum free fatty acids (FFAs) have shown antibacterial activity against a broad range of gram-positive bacteria, resulting in the suggestion that they are accountable, at least partially, for the direct antimicrobial activity of the skin surface. In this study, we examined the effects of sebum FFAs on the antimicrobial peptide (AMP)-mediated innate immune defense of human sebocytes. Incubation of lauric acid, palmitic acid, or oleic acid (OA) with human sebocytes dramatically enhanced their expression of human beta-defensin (hBD)-2, one of the predominant AMPs found in the skin, whereas remarkable increases in hBD-1, hBD-3, and human cathelicidin LL-37 were not observed. Secreted hBD-2 was detectable by western blotting in the supernatant of sebocyte culture incubated with each FFA, but not with a vehicle control. The supernatant of FFA-incubated sebocyte culture showed antimicrobial activity against Propionibacterium acnes, whereas the enhanced antimicrobial activity of human sebocytes was neutralized by anti-hBD-2 IgG. In addition, the FFA-induced hBD-2 expression was suppressed by blocking the cluster of differentiation (CD)36 fatty acid translocase on the surface of sebocytes with anti-human CD36 IgG or blocking the NF-kappaB signaling pathway with BMS-345541, a highly selective inhibitor of inhibitory kappaB kinase. These data suggest that sebum FFAs upregulate the expression of hBD-2 in human sebocytes, which may enhance the disinfecting activity of the human sebaceous gland. The FFA-induced upregulation of hBD-2 is facilitated by CD36-mediated FFA uptake and NF-kappaB-mediated transactivation. The upregulation of mouse beta-defensin 4, a mouse ortholog for hBD-2, was also observed in the hair follicle sebaceous glands of mouse ear skin after an epicutaneous application of OA, the most hBD-2-inducible FFA tested. This report highlights the potential of using FFAs as a multifunctional antimicrobial therapy agent for acne vulgaris treatment; FFAs may provide direct antibacterial activities against P. acnes and enhance the skin's innate antibacterial defense by inducing the expression of hBD-2 in sebocytes as well.


Assuntos
Ácidos Graxos não Esterificados/imunologia , Glândulas Sebáceas/imunologia , Sebo/imunologia , beta-Defensinas/metabolismo , Acne Vulgar/tratamento farmacológico , Acne Vulgar/imunologia , Acne Vulgar/microbiologia , Animais , Antígenos CD36/imunologia , Antígenos CD36/metabolismo , Linhagem Celular Transformada , Ácidos Graxos não Esterificados/farmacologia , Feminino , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/imunologia , Folículo Piloso/citologia , Folículo Piloso/imunologia , Folículo Piloso/metabolismo , Humanos , Imunoglobulina G/farmacologia , Ácidos Láuricos/imunologia , Ácidos Láuricos/farmacologia , Camundongos , Camundongos Endogâmicos ICR , NF-kappa B/metabolismo , Ácido Oleico/imunologia , Ácido Oleico/farmacologia , Ácido Palmítico/imunologia , Ácido Palmítico/farmacologia , Propionibacterium acnes/efeitos dos fármacos , Propionibacterium acnes/imunologia , Glândulas Sebáceas/citologia , Glândulas Sebáceas/metabolismo , Sebo/metabolismo , Transdução de Sinais/imunologia , Regulação para Cima/fisiologia , beta-Defensinas/imunologia
10.
BMC Immunol ; 10: 29, 2009 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-19463182

RESUMO

BACKGROUND: Diabetes is characterized by progressive failure of insulin producing beta cells. It is well known that both saturated fatty acids and various products of immune cells can contribute to the reduction of beta cell viability and functionality during diabetes pathogenesis. However, their joint action on beta cells has not been investigated, so far. Therefore, we explored the possibility that leukocytes and saturated fatty acids cooperate in beta cell destruction. RESULTS: Rat pancreatic islets or insulinoma cells (RIN) were co-cultivated with concanavalin A (ConA)-stimulated rat lymph node cells (LNC), or they were treated with cell-free supernatants (Sn) obtained from ConA-stimulated spleen cells or from activated CD3+ cells, in the absence or presence of palmitic acid (PA). ConA-stimulated LNC or Sn and PA cooperated in inducing caspase-3-dependent RIN cell apoptosis. The observed effect of PA and Sn on RIN cell viability was mediated by p38 mitogen-activated protein kinase (MAPK)-signaling and was achieved through auto-destructive nitric oxide (NO) production. The cooperative effect of Sn was mimicked with the combination of interleukin-1beta, interleukin-2, interleukin-6, interleukin-17, interferon-gamma and tumor necrosis factor-alpha. CONCLUSION: These results imply that stimulated T cells produce cytokines that cooperate with saturated free fatty acids in beta cell destruction during diabetes pathogenesis.


Assuntos
Apoptose/imunologia , Comunicação Celular , Células Secretoras de Insulina/imunologia , Insulinoma/imunologia , Ácido Palmítico/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Caspase 3/metabolismo , Linhagem Celular Tumoral , Técnicas de Cocultura , Citocinas/imunologia , Citocinas/metabolismo , Células Secretoras de Insulina/patologia , Insulinoma/patologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Ácido Palmítico/imunologia , Ratos , Transdução de Sinais , Linfócitos T/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
J Biol Chem ; 282(18): 13884-94, 2007 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-17341584

RESUMO

The coreceptor CD8 is expressed as a CD8alphabeta heterodimer on major histocompatibility complex class I-restricted TCRalphabeta T cells, and as a CD8alphaalpha homodimer on subsets of memory T cells, intraepithelial lymphocytes, natural killer cells, and dendritic cells. Although the role of CD8alphaalpha is not well understood, it is increasingly clear that this protein is not a functional homologue of CD8alphabeta. On major histocompatibility complex class I-restricted T cells, CD8alphabeta is a more efficient TCR coreceptor than CD8alphaalpha. This property has for the mouse protein been attributed to the recruitment of CD8alphabeta into lipid rafts, which is dependent on CD8beta palmitoylation. Here, these divergent distributions of CD8alphabeta and CD8alphaalpha are demonstrated for the human CD8 proteins as well. However, although palmitoylation of both CD8alpha and CD8beta chains was detected, this modification did not contribute to raft localization. In contrast, arginines in the cytoplasmic domain are crucial for raft localization of CD8betabeta. Most strikingly, the assembly of a non-raft localized CD8beta chain with a non-raft localized CD8alpha chain resulted in raft-localized CD8alphabeta heterodimers. Using chimeric CD8 proteins, this property of the heterodimer was found to be determined by the assembly of CD8alpha and CD8beta extracellular regions. The presence of two CD8alpha extracellular regions, on the other hand, appears to preclude raft localization. Thus, heterodimer formation and raft association are intimately linked for CD8alphabeta. These results emphasize that lipid raft localization is a key feature of human CD8alphabeta that clearly distinguishes it from CD8alphaalpha.


Assuntos
Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/imunologia , Memória Imunológica , Microdomínios da Membrana/imunologia , Processamento de Proteína Pós-Traducional/imunologia , Antígenos CD8/genética , Linhagem Celular , Células Dendríticas/imunologia , Dimerização , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Memória Imunológica/genética , Células Matadoras Naturais/imunologia , Microdomínios da Membrana/genética , Ácido Palmítico/imunologia , Processamento de Proteína Pós-Traducional/genética , Estrutura Terciária de Proteína/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia
12.
Infect Immun ; 75(5): 2253-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17325056

RESUMO

Genomic analysis of Mycoplasma pneumoniae revealed the existence of a large number of putative lipoprotein genes compared with the numbers in other bacteria. However, the pathogenic roles of M. pneumoniae lipoproteins are still obscure. In this study, we synthesized a lipopeptide (designated M. pneumoniae paralogous lipoprotein 1 [MPPL-1]) in which an S-dipalmitoylglyceryl cysteine was coupled to a peptide with a consensus sequence of a putative paralogous lipoprotein group characteristic of M. pneumoniae. The cytokine-inducing activity of MPPL-1 in human monocytic cells was much weaker (approximately 700-fold weaker) than that of the known mycoplasmal S-dipalmitoylated lipopeptide FSL-1 or MALP-2. MPPL-1 required Toll-like receptor (TLR2) to activate NF-kappaB-dependent gene transcription in HEK293 cells, although a 1,000-fold-larger amount of MPPL-1 was needed to exert activity similar to that of FSL-1 in the cells. TLR2-mediated recognition of MPPL-1 was synergistically upregulated by TLR6 but not by TLR1 or TLR10, although the activity was still weak. In addition, MPPL-1 did not antagonize FSL-1 recognition in human monocytic cells and TLR2/TLR6-expressing HEK293 cells. Thus, these results suggest that there is preferential selective recognition of diacylated lipopeptides due to the magnitude of an affinity with TLR2 and TLR6 and the roles of increased paralogous lipoprotein genes of M. pneumoniae in evasion of TLR2 recognition.


Assuntos
Lipoproteínas , Mycoplasma pneumoniae/química , Ácido Palmítico , Sequência de Aminoácidos , Linhagem Celular , Citocinas/metabolismo , Diglicerídeos/imunologia , Regulação da Expressão Gênica , Humanos , Lipopeptídeos , Lipoproteínas/síntese química , Lipoproteínas/química , Lipoproteínas/imunologia , Ativação de Macrófagos , Dados de Sequência Molecular , Monócitos/imunologia , Mycoplasma pneumoniae/imunologia , Oligopeptídeos/imunologia , Ácido Palmítico/síntese química , Ácido Palmítico/química , Ácido Palmítico/imunologia , Receptor 2 Toll-Like/metabolismo , Receptores Toll-Like/metabolismo
13.
Eur J Immunol ; 34(12): 3497-507, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15495162

RESUMO

Small structural changes in the antigenic peptides recognized by TCR can alter the biological properties of those peptides and convert them into weak agonists, partial agonists, or antagonists of these receptors. These altered peptide ligands (APL) are usually generated by conservative amino acid substitutions at TCR contact residues. Here, we show that APL with therapeutic properties can also be generated by attachment of palmitic acid at the N terminus of the peptide without the need to modify the peptide's primary sequence. Using N-palmitoylated pigeon cytochrome-c peptide 81-104 (PALPCC(81-104)), we were able to induce T cell hyporesponsiveness to the wild-type peptide in vitro. More importantly, administration of the PALPCC(81-104 )to mice reduced the responsiveness to the native peptide when tested ex vivo. Biochemical and functional experiments indicated that the action of N-palmitoylated peptides was due to the conversion of the native peptide into a weak agonist that could then induce T cell anergy. Our results demonstrate that N-palmitoylation of antigenic peptides is a feasible strategy to generate APL, as it avoids the need to screen multiple amino acid variants of each specific antigen to identify those with therapeutic properties.


Assuntos
Ácido Palmítico/metabolismo , Fragmentos de Peptídeos/imunologia , Linfócitos T/imunologia , Animais , Feminino , Tolerância Imunológica/imunologia , Camundongos , Ácido Palmítico/imunologia , Fragmentos de Peptídeos/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T/metabolismo
14.
J Immunol Methods ; 234(1-2): 23-34, 2000 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-10669766

RESUMO

The reactivities of two panels of anti-HAV human sera from geographically distinct areas (Chile and Spain) to synthetic peptides from the VP1, VP2 and VP3 hepatitis A virus capsid proteins were examined by an enzyme-linked immunosorbent assay (ELISA) procedure. Two and four branched multiple antigenic peptides (MAPs) and palmitoylated peptides were compared with free synthetic sequences for the detection of IgM anti-HAV antibodies in the two panels of human sera. Our results showed that acute hepatitis A patient sera recognized preferentially homogeneous two branched MAPs and palmitic acid conjugated peptides. The palmitoyl-derived VP3(110-121) peptide and the corresponding dimeric MAP were the most sensitive and appropriate for serological studies of HAV-infected patients by ELISA, sensitivity and specificity being higher than 90% and 95%, respectively. These peptide-based tests open up new avenues in the development of peptide-based immunosorbent assays for the detection of acute HAV disease.


Assuntos
Antígenos Virais/imunologia , Capsídeo/imunologia , Hepatite A/diagnóstico , Fragmentos de Peptídeos/imunologia , Proteínas Estruturais Virais/imunologia , Doença Aguda , Capsídeo/síntese química , Proteínas do Capsídeo , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos de Linfócito B/imunologia , Hepatite A/sangue , Hepatite A/imunologia , Anticorpos Anti-Hepatite A , Antígenos da Hepatite A , Anticorpos Anti-Hepatite/sangue , Anticorpos Anti-Hepatite/imunologia , Humanos , Testes Imunológicos/métodos , Ácido Palmítico/imunologia , Fragmentos de Peptídeos/síntese química , Peptídeos/síntese química , Peptídeos/imunologia , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Proteínas Estruturais Virais/síntese química
15.
Hepatology ; 30(2): 531-6, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10421664

RESUMO

Clinical observations suggest that eradication of the hepatitis B virus (HBV) is immune-mediated. Vigorous cytotoxic T lymphocyte (CTL) activity directed at HLA class I-bound viral epitopes are detected during acute hepatitis B, but not in chronic hepatitis B carriers. A CTL epitope derived from the hepatitis B core protein amino acids 18-27 has been incorporated into a vaccine also comprised of a T-helper cell epitope and 2 palmitic acid residues (CY-1899). The aim of this study was to determine whether repeated doses of CY-1899 given to patients with chronic hepatitis B could initiate in vivo CTL activity and viral clearance. Patients with chronic hepatitis B received up to 4 doses (ranging from 0.05 mg to 15 mg) 6 weeks apart. Following vaccination, patients were monitored for hepatitis B surface antigen and "e" status, HBV-DNA levels, liver biochemistry, CTL activity, and any adverse events. Ninety patients with chronic hepatitis B infection received CY-1899. Mean CTL responses were all low but were maximal following vaccination with 5 mg CY-1899. Peak CTL responses never exceeded 10 lytic units (LU) regardless of vaccine dose, this value being well below that seen following resolution of acute hepatitis B. No significant changes in liver biochemistry or viral serology were observed during follow-up. No serious adverse events were noted. Administration of the single-epitope vaccine, CY-1899, initiated CTL activity, but of a magnitude lower than that observed during spontaneous HBV clearance. This low-level CTL activity was not associated with viral clearance.


Assuntos
Epitopos de Linfócito T , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Hepatite B Crônica/terapia , Ácido Palmítico/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinas Virais/uso terapêutico , Adulto , Idoso , Sequência de Aminoácidos , Feminino , Humanos , Imunização , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Projetos Piloto
16.
J Autoimmun ; 12(3): 177-89, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10222027

RESUMO

We reported previously that acylation of an encephalitogenic peptide of myelin basic protein (MBP68-86) by attachment of palmitoyl chloride (PAL68-86) converted this peptide into a powerful tolerogen for EAE in the Lewis rat. In this study we show that T cell lines derived from a PAL68-86-protected rat proliferated poorly to MBP68-86 in vitro, even after repeated passages in this peptide and IL-2. Conversely, T cell lines derived from untreated rats that were challenged with MBP68-86 or PAL68-86 in CFA responded vigorously to MBP68-86 when propagated for many passages in this peptide but became gradually unresponsive after being propagated in the presence of PAL68-86. The modulation of the T cell lines by PAL68-86 in vitro was reflected by a significant reduction in their ability to transfer EAE to recipients. A high percentage of cells stained with an anti-Vbeta8.2 antibody, regardless of whether they were propagated in the presence of unmodified or acylated peptide. The results are consistent with the notion that tolerance induced by PAL68-86 operates by functional inactivation and provide the basis for the use of acylated peptides in the antigen-specific treatment of autoimmune diseases.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Tolerância Imunológica , Proteína Básica da Mielina/imunologia , Ácido Palmítico/imunologia , Fragmentos de Peptídeos/imunologia , Linfócitos T/imunologia , Acilação , Animais , Linhagem Celular , Masculino , Proteína Básica da Mielina/química , Ácido Palmítico/química , Fragmentos de Peptídeos/química , Ratos , Ratos Endogâmicos Lew , Linfócitos T/transplante
17.
Infect Immun ; 65(1): 267-71, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8975922

RESUMO

The ribosomal protein L7/L12 isolated from Brucella melitensis induces a delayed-type hypersensitivity (DTH) reaction in brucella-sensitized guinea pigs. Surprisingly, the recombinant brucella L7/L12 protein expressed in Escherichia coli as a fusion protein with a six-histidine tag cannot elicit such a reaction. The six histidines tagged to the recombinant L7/L12 protein were removed enzymatically, but the resulting protein did not induce a DTH reaction in sensitized animals. Incubation of the recombinant L7/L12 fusion protein in a B. melitensis lysate endowed the recombinant protein with a DTH activity, suggesting that the recombinant protein was modified by this treatment. Glycosylation or phosphorylation of the recombinant L7/L12 protein could not be detected. On the other hand, radiolabeled palmitic acid was found to be incorporated to the recombinant protein during its incubation in the brucella lysate. This incorporation was specific for the brucella L7/L12 protein and was inhibited when the brucella lysate was frozen and thawed before the incubation. The data reported here indicate that posttranslational modification of L7/L12 protein comprising at least an acylation step is required for the brucella L7/L12 DTH activity.


Assuntos
Proteínas de Bactérias/imunologia , Brucella melitensis/imunologia , Hipersensibilidade Tardia , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/imunologia , Alérgenos/imunologia , Animais , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli , Glicosilação , Cobaias , Masculino , Ácido Palmítico/imunologia , Ácido Palmítico/metabolismo , Fosforilação , Proteínas Recombinantes de Fusão/imunologia , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo
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