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1.
J Viral Hepat ; 24(2): 155-162, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27807909

RESUMO

A persistent hepatitis B virus (HBV) infection is characterized by a lack of or a weak immune response to HBV, which may be reflective of tolerance to HBV. Efficient induction of HBV-specific immune response leads to the clearance of HBV in patients with a chronic HBV infection. CpG oligodeoxynucleotides (ODN) has a powerful adjuvant effect in HBV vaccination. A recent report demonstrated that the immunization by B/K CpG ODN (K3) wrapped by the nonagonistic Dectin-1 ligand, schizophyllan (SPG), namely K3-SPG, was more effective in the induction of antigen-specific immune response than that by K3. In this study, we examined the efficacy of K3-SPG as a HBV vaccine adjuvant. Wild-type (WT) mice and HBV transgenic (HBV-Tg) mice were subcutaneously immunized with hepatitis B surface antigen (HBsAg) alone, HBsAg and K3, or HBsAg and K3-SPG. The vaccination with HBsAg and K3-SPG significantly enhanced humoral and cellular immune response to HBV antigen compared to the other vaccinations in WT and HBV-Tg mice. K3-SPG induced the accumulation of dendritic cells (DCs) into draining lymph node and the activation of DCs. The expression of cytokines and chemokines related to Th1 and Th2 responses was upregulated after the vaccination including with K3-SPG. In conclusion, these results indicated that the vaccination using K3-SPG may overcome tolerance even in patients with chronic HBV infection.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Imunidade Celular , Imunidade Humoral , Oligodesoxirribonucleotídeos/administração & dosagem , Sizofirano/administração & dosagem , Animais , Antígenos de Superfície da Hepatite B/administração & dosagem , Antígenos de Superfície da Hepatite B/imunologia , Injeções Subcutâneas , Masculino , Camundongos
2.
Clin Exp Allergy ; 46(7): 992-1003, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26892276

RESUMO

BACKGROUND: The relationship among natural allergen exposure, induction of blocking antibody and the occurrence of atopic allergy-particularly in the presence of IgE production-is debatable. OBJECTIVE: To clarify the relationship between the dose of cutaneous exposure to dust mite allergen and susceptibility to the IgE-mediated allergic response in relation to IgG production. METHODS: NC/Nga mice were epicutaneously exposed to various doses of Dermatophagoides pteronyssinus allergen to induce atopic dermatitis-like skin lesions. We then evaluated the skin lesions, induction of mite-specific immune responses, and susceptibility to anaphylaxis. RESULTS: Dose-dependent exacerbation of atopic dermatitis-like skin lesions and increases in mite-specific IgG and IgE production were observed. However, mice exposed to relatively low doses of mite allergen showed hypersusceptibility to mite allergen-specific anaphylaxis. We also showed that adoptive transfer of total IgG from Dp-sensitized mice rescued mice from the hypersusceptibility seen in those exposed to low doses of mite allergen. CONCLUSIONS AND CLINICAL RELEVANCE: High-dose cutaneous exposure to dust mites induced effective blocking IgG production, even if accompanied by IgE production. Our data might support the concept that an increase in IgG titre, not a decrease in IgE titre, is a marker of clinical improvement in allergen-specific immunotherapy.


Assuntos
Alérgenos/administração & dosagem , Alérgenos/imunologia , Anafilaxia/prevenção & controle , Anticorpos Bloqueadores/imunologia , Antígenos de Dermatophagoides/administração & dosagem , Antígenos de Dermatophagoides/imunologia , Imunoglobulina G/imunologia , Anafilaxia/imunologia , Anafilaxia/metabolismo , Animais , Especificidade de Anticorpos/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Imunização , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Camundongos
3.
Eur Respir J ; 38(3): 688-701, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21273385

RESUMO

Mycobacteria are among the most common causes of hypersensitivity pneumonitis (HP), but controversy persists with regard to the involvement of the infectious potency of the organism in mycobacterial HP (hot tub lung). This study aimed to establish a mouse model of hot tub lung to clarify its pathophysiology. Mice were exposed intranasally to formalin-killed Mycobacterium avium from a patient with hot tub lung (HP strain) or chronic pulmonary infection (non-HP strain), and bronchoalveolar lavage fluids and lung tissues were evaluated for allergic inflammation. Dead M. avium HP strain, but not non-HP strain, elicited marked HP-like pulmonary inflammation in wild-type mice. Although the inflammation was induced in mice lacking CD4 or CD8, the induction of HP-like responses was prevented in mice lacking myeloid differentiation factor (MyD)88 or Toll-like receptor (TLR)9. Cultured lung CD11c+ cells responded to M. avium in a TLR9-dependent manner, and reconstitution of TLR9-/- mice with lung CD11c+ cells from wild-type mice restored the inflammatory responses. Further investigation revealed that pulmonary exposure to M. avium HP strain increased the number of lung CD11b+ CD11c+ cells (dendritic cells) through TLR9 signalling. Our results provide evidence that hot tub lung develops via the mycobacterial engagement of TLR9-MyD88 signalling in lung CD11b+ dendritic cells independent of the mycobacterial infectious capacity.


Assuntos
Alveolite Alérgica Extrínseca/metabolismo , Alveolite Alérgica Extrínseca/microbiologia , Antígeno CD11b/biossíntese , Antígeno CD11c/biossíntese , Mycobacterium/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Receptor Toll-Like 9/metabolismo , Idoso , Animais , Feminino , Humanos , Imunidade Inata , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium avium/metabolismo , Transdução de Sinais
4.
Drug News Perspect ; 13(5): 289-96, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12937643

RESUMO

Bacterial DNA and synthetic oligodeoxynucleotides (ODN) expressing unmethylated CpG motifs stimulate the mammalian immune system to mount a rapid innate immune response. This response is characterized by the production of polyreactive IgM, immunomodulatory cytokines and chemokines. CpG ODN directly stimulate lymphocytes, natural killer cells and professional antigen-presenting cells (such as macrophages and dendritic cells). Owing to the strength and nature of this stimulation, CpG ODN are being harnessed for a variety of therapeutic uses. They are being tested for their ability to act as immune adjuvants, boosting the immune response elicited by conventional and DNA vaccines. As a result of their ability to activate a strong interferon gamma-dominated Th1 response while blocking the development of Th2-dependent allergies, CpG ODN are being examined for their antiallergic properties. Finally, CpG ODN are being used as "immunoprotective agents", since the innate immune response they elicit can protect the host from a variety of pathogenic bacteria, viruses and parasites.

6.
Vaccine ; 18(7-8): 703-10, 1999 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-10547430

RESUMO

A plasmid DNA vaccine encoding the circumsporozoite protein of malaria (pCSP) induces protective immunity in adult mice but persistent tolerance when administered to neonates. In an effort to improve antigen presenting cell (APC) function in newborns, we co-administered pCSP with a plasmid encoding granulocyte-macrophage colony stimulating factor (pGMCSF). This combination of plasmids prevented the development of neonatal tolerance, instead eliciting a primary IgG anti-CSP immune response. Mice primed as neonates and boosted as adults mounted anamnestic responses characterized by high serum antibody titers, cytotoxic T-cell activity and antigen-specific interferon gamma (IFNgamma) production. Neonatal administration of pGMCSF accelerated the maturation of local dendritic cells, suggesting that APC function plays a key role in determining whether tolerance or immunity results from neonatal exposure to antigen.


Assuntos
Animais Recém-Nascidos/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Tolerância Imunológica , Vacinas de DNA/imunologia , Animais , Células Apresentadoras de Antígenos/citologia , Células Apresentadoras de Antígenos/imunologia , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Células Dendríticas/imunologia , Feminino , Humanos , Tolerância Imunológica/genética , Interferon gama/biossíntese , Interferon gama/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/administração & dosagem , Plasmídeos/imunologia , Plasmodium yoelii/genética , Plasmodium yoelii/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinas de DNA/genética
7.
Cell Immunol ; 206(2): 101-6, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11161441

RESUMO

Intramuscular injection of synthetic oligodeoxynucleotides (ODN) expressing unmethylated CpG motifs trigger the rapid development of a local inflammatory response. In vitro studies demonstrate that macrophages exposed to CpG ODN up-regulate expression of mRNA encoding the chemokines MIP-1alpha, MIP-1beta, MIP-2, RANTES, JE/MCP-1, and IP-10. Within 6 h of in vivo administration, CpG ODN induce a significant increase in chemokine mRNA levels at the site of injection and draining lymph nodes. These chemokines may contribute to the migration and stimulation of inflammatory cells that contribute to the development of CpG ODN-induced immune responses.


Assuntos
Adjuvantes Imunológicos/farmacologia , Quimiocinas/biossíntese , Macrófagos/imunologia , Macrófagos/metabolismo , Oligodesoxirribonucleotídeos/farmacologia , RNA Mensageiro/biossíntese , Regulação para Cima/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Linhagem Celular , Células Cultivadas , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocina CCL5/biossíntese , Quimiocina CCL5/genética , Quimiocina CXCL10 , Quimiocina CXCL2 , Quimiocinas/genética , Quimiocinas CXC/biossíntese , Quimiocinas CXC/genética , Feminino , Inflamação/imunologia , Inflamação/metabolismo , Injeções Intramusculares , Interferon gama/fisiologia , Linfonodos/citologia , Linfonodos/imunologia , Linfonodos/patologia , Proteínas Inflamatórias de Macrófagos/biossíntese , Proteínas Inflamatórias de Macrófagos/genética , Camundongos , Camundongos Endogâmicos BALB C , Músculo Esquelético/imunologia , Músculo Esquelético/patologia , Oligodesoxirribonucleotídeos/administração & dosagem , Baço/citologia , Baço/imunologia
8.
Eur J Immunol ; 30(1): 108-16, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10602032

RESUMO

Oligonucleotides (ODN) expressing immunostimulatory "CpG motifs" activate human RPMI 8226 myeloma cells to secrete IL-6. Using deletion and site-directed mutagenesis of the human (h)IL-6 promoter region, two positive regulatory elements (the binding sites for the 5'-CCAAT / enhancer binding protein-beta and NF-kappaB) were identified. Two negative regulatory elements, the 3'-retinoblastoma control element (RCE) and the binding site for Epstein-Barr virus C-promoter binding factor 1 (CBF1), also contributed to CpG ODN induction of hIL-6 gene expression. Of interest, CpG ODN treatment induced the dissociation of a repressor protein from its 3'-RCE binding site. Thus, CpG ODN regulation of hIL-6 gene expression involves both enhancer and derepression mechanisms.


Assuntos
Fosfatos de Dinucleosídeos/farmacologia , Regulação da Expressão Gênica , Interleucina-6/genética , Oligonucleotídeos/farmacologia , Proteínas Estimuladoras de Ligação a CCAAT , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Interleucina-6/biossíntese , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Células Tumorais Cultivadas
9.
Gene Ther ; 6(2): 237-44, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10435108

RESUMO

Cytokine-encoding DNA plasmids can act as 'genetic adjuvants', improving the immune response stimulated by co-administered DNA vaccines. We examined whether plasmids encoding the Th1 cytokine IFN gamma (pIFN gamma) or the Th2 cytokine IL-4 (pIL-4) have long-term effects on immune homeostasis when administered to adult mice, or alter immune maturation in neonates. Both plasmids boosted immunity against a co-administered vaccine, with pIFN gamma promoting the development of a Th1 response (characterized by the production of IgG2a antibodies), and pIL-4 preferentially stimulating a Th2 response (characterized by increased IgG1 antibody production). Both pIFN gamma and pIL-4 influenced the ratio of cells actively secreting Th1 versus Th2 cytokines, consistent with an effect on Th cell maturation. Interestingly, this effect persisted for only a few weeks and was not magnified by repeated plasmid administration. Cytokine-encoding plasmids had no long-term effect on the immune response of newborn or adult mice to subsequent antigenic stimulation, nor did they selectively induce the production of pathogenic anti-DNA autoantibodies. These results suggest cytokine-encoding plasmids may be safe as immune adjuvants.


Assuntos
Adjuvantes Imunológicos , Terapia Genética/métodos , Interferon gama/genética , Interleucina-4/genética , Plasmídeos/administração & dosagem , Vacinas de DNA/administração & dosagem , Animais , Animais Recém-Nascidos , Anticorpos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G , Camundongos , Camundongos Endogâmicos BALB C , Células Th1/imunologia , Células Th2/imunologia
10.
J Immunol ; 167(6): 3324-8, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11544321

RESUMO

Immunostimulatory CpG oligonucleotides (ODN) show promise as immune adjuvants, anti-allergens, and immunoprotective agents. Increasing the bioavailability and duration of action of CpG ODN should improve their therapeutic utility. Encapsulating ODN in sterically stabilized cationic liposomes provides protection from serum nucleases while facilitating uptake by B cells, dendritic cells, and macrophages. In a pathogen challenge model, sterically stabilized cationic liposomes encapsulation doubled the duration of CpG ODN-induced immune protection. In an immunization model, coencapsulation of CpG ODN with protein Ag (OVA) magnified the resultant Ag-specific IFN-gamma and IgG responses by 15- to 40-fold compared with Ag plus CpG ODN alone. These findings support the use of sterically stabilized cationic liposomes to significantly enhance the therapeutic efficacy of CpG ODN.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Ilhas de CpG , Lipossomos/farmacologia , Adjuvantes Imunológicos/farmacocinética , Adjuvantes Imunológicos/farmacologia , Animais , Apresentação de Antígeno , Antígenos/imunologia , Líquido Ascítico/metabolismo , Antígenos CD40/biossíntese , Antígenos CD40/genética , Cátions , Portadores de Fármacos , Composição de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Imunização , Injeções Intraperitoneais , Dose Letal Mediana , Lipossomos/administração & dosagem , Lipossomos/química , Listeria monocytogenes/imunologia , Listeriose/imunologia , Listeriose/prevenção & controle , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Organismos Livres de Patógenos Específicos , Baço/metabolismo
11.
J Immunol ; 166(4): 2372-7, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11160295

RESUMO

Oligodeoxynucleotides (ODN) that contain unmethylated CpG dinucleotides trigger a strong innate immune response in vertebrates. CpG ODN show promise as vaccine adjuvants, anti-allergens, and immunoprotective agents in animal models. Their transition to clinical use requires the identification of motifs that are optimally stimulatory in humans. Analysis of hundreds of novel ODN resulted in the identification and characterization of two structurally distinct "clusters" of immunostimulatory CpG ODN. One cluster ("D") preferentially stimulates IFN-gamma production by NK cells, whereas the other ("K") stimulates cell proliferation and the production of IL-6 and IgM by monocytes and B cells. The distinct immunostimulatory properties of K and D ODN can improve the design of CpG-based products to achieve specific therapeutic goals.


Assuntos
Ilhas de CpG/imunologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Divisão Celular/imunologia , Linhagem Celular , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Humanos , Imunoglobulina M/biossíntese , Interferon gama/metabolismo , Interleucina-6/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Leucócitos Mononucleares/citologia , Ativação Linfocitária/imunologia , Monócitos/imunologia , Monócitos/metabolismo , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/farmacologia , Células Tumorais Cultivadas
12.
Clin Exp Immunol ; 127(2): 234-42, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11876745

RESUMO

Although infection of single-stranded RNA viruses can enhance expression of major histocompatibility complex (MHC) class I genes, the mechanism underlying this process remains unclear. Recent studies have indicated that exposure of non-immune cells to double-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) of viral origin can directly increase the expression of MHC class I and related molecules without immune cell interaction. In this report, we show that transfection of single-stranded hepatitis A virus RNA into cultured hepatocytes results in the induction of genes for MHC class I, LMP2 and transporter for antigen processing (TAP1), in addition to the generation of viral proteins. We suggest that this stimulatory effect is due to the double-stranded RNA formed during replication of single-stranded viral RNA, and involves both double-stranded, RNA-dependent protein kinase PKR and the secretion of IFNbeta.


Assuntos
Regulação Viral da Expressão Gênica , Genes MHC Classe I , Vírus da Hepatite A/genética , Hepatócitos/imunologia , Antígenos de Histocompatibilidade Classe I/biossíntese , Proteínas I-kappa B , RNA Viral/fisiologia , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/biossíntese , Transportadores de Cassetes de Ligação de ATP/genética , Células Cultivadas/imunologia , Proteínas de Ligação a DNA/metabolismo , Vírus da Hepatite A/fisiologia , Hepatoblastoma/patologia , Humanos , Interferon beta/metabolismo , Neoplasias Hepáticas/patologia , NF-kappa B/metabolismo , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Fosforilação , Processamento de Proteína Pós-Traducional , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/fisiologia , RNA Mensageiro/biossíntese , RNA Viral/genética , Transfecção , Células Tumorais Cultivadas/imunologia , Proteínas da Matriz Viral/biossíntese , Proteínas da Matriz Viral/genética , Proteínas Virais/biossíntese , Proteínas Virais/genética , Replicação Viral , eIF-2 Quinase/fisiologia
13.
Rheumatology (Oxford) ; 42(4): 563-9, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12649404

RESUMO

OBJECTIVES: Increased levels of hypomethylated CpG-containing DNA in sera from patients with systemic lupus erythematosus (SLE) may contribute to the initiation and/or perpetuation of the disease. This study characterizes the in vitro response of peripheral blood mononuclear cells (PBMC) from SLE patients to CpG DNA. METHODS: Secretion of cytokines and IgM, cell proliferation and up-regulation of co-stimulatory molecules were evaluated in PBMC from SLE patients (n=24) and normal controls (n=24) after stimulation with synthetic oligodeoxynucleotides (ODN) containing CpG motifs. RESULTS: Up-regulation of co-stimulatory molecules and the secretion of interferon-alpha and interleukin-6 (IL-6) in response to CpG ODN was significantly reduced in monocytes and dendritic cells from SLE patients. Secretion of interferon-gamma by natural killer (NK) cells was also reduced. In contrast, the IgM and IL-10 response of B cells to CpG ODN was normal. CONCLUSION: Monocytes, dendritic cells and NK cells from SLE patients respond abnormally to CpG ODN stimulation, which may contribute to the cytokine imbalance observed in SLE.


Assuntos
Ilhas de CpG/imunologia , Leucócitos Mononucleares/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Oligodesoxirribonucleotídeos/imunologia , Idoso , Divisão Celular/imunologia , Células Cultivadas , Citocinas/sangue , Células Dendríticas/imunologia , Feminino , Humanos , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Regulação para Cima
14.
J Immunol ; 162(7): 3814-8, 1999 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-10201898

RESUMO

A plasmid DNA vaccine encoding the circumsporozoite protein of malaria (pCSP) induces tolerance rather than immunity when administered to newborn mice. We find that this tolerance persists for >1 yr after neonatal pCSP administration and interferes with the induction of protective immunity in animals challenged with live sporozoites. Susceptibility to tolerance induction wanes rapidly with age, disappearing within 1 wk of birth. Higher doses of plasmid are more tolerogenic, and susceptibility to tolerance is not MHC-restricted. CD8+ T cells from tolerant mice suppress the in vitro Ag-specific immune response of cells from adult mice immunized with pCSP. Similarly, CD8+ T cells from tolerant mice transfer nonresponsiveness to naive syngeneic recipients. These findings clarify the cellular basis and factors contributing to the development of DNA vaccine-induced neonatal tolerance.


Assuntos
Animais Recém-Nascidos/imunologia , Tolerância Imunológica , Plasmídeos/imunologia , Vacinas de DNA/imunologia , Animais , Animais Recém-Nascidos/genética , Suscetibilidade a Doenças , Relação Dose-Resposta Imunológica , Feminino , Tolerância Imunológica/genética , Imunidade Celular/genética , Injeções Intramusculares , Malária/genética , Malária/imunologia , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Plasmídeos/administração & dosagem , Plasmídeos/genética , Plasmodium yoelii/genética , Plasmodium yoelii/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética
15.
J Immunol ; 167(7): 3555-8, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11564765

RESUMO

Unmethylated CpG motifs present in bacterial DNA stimulate a rapid and robust innate immune response. Human cell lines and PBMC that recognize CpG DNA express membrane-bound human Toll-like receptor 9 (hTLR9). Cells that are not responsive to CpG DNA become responsive when transfected with hTLR9. Expression of hTLR9 dramatically increases uptake of CpG (but not control) DNA into endocytic vesicles. Upon cell stimulation, hTLR9 and CpG DNA are found in the same endocytic vesicles. Cells expressing hTLR9 are stimulated by CpG motifs that are active in primates but not rodents, suggesting that evolutionary divergence between TLR9 molecules underlies species-specific differences in the recognition of bacterial DNA. These findings indicate that hTLR9 plays a critical role in the CpG DNA-mediated activation of human cells.


Assuntos
Ilhas de CpG , Proteínas de Ligação a DNA/fisiologia , Oligodesoxirribonucleotídeos/farmacologia , Receptores de Superfície Celular/fisiologia , Linhagem Celular , Células Cultivadas , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Humanos , Quinases Associadas a Receptores de Interleucina-1 , Células Jurkat , Proteínas Quinases/fisiologia , Estrutura Terciária de Proteína , Proteínas/fisiologia , RNA Mensageiro/biossíntese , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Transdução de Sinais , Fator 6 Associado a Receptor de TNF , Receptor Toll-Like 9 , Transfecção , Vesículas Transportadoras/química
16.
Proc Natl Acad Sci U S A ; 96(5): 2285-90, 1999 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-10051633

RESUMO

Abnormal expression of major histocompatibility complex (MHC) class I and class II in various tissues is associated with autoimmune disease. Autoimmune responses can be triggered by viral infections or tissue injuries. We show that the ability of a virus or a tissue injury to increase MHC gene expression is duplicated by any fragment of double-stranded (ds) DNA or dsRNA introduced into the cytoplasm of nonimmune cells. Activation is sequence-independent, is induced by ds polynucleotides as small as 25 bp in length, and is not duplicated by single-stranded polynucleotides. In addition to causing abnormal MHC expression, the ds nucleic acids increase the expression of genes necessary for antigen processing and presentation: proteasome proteins (e.g., LMP2), transporters of antigen peptides; invariant chain, HLA-DM, and the costimulatory molecule B7.1. The mechanism is different from and additive to that of gamma-interferon (gammaIFN), i.e., ds polynucleotides increase class I much more than class II, whereas gammaIFN increases class II more than class I. The ds nucleic acids also induce or activate Stat1, Stat3, mitogen-activated protein kinase, NF-kappaB, the class II transactivator, RFX5, and the IFN regulatory factor 1 differently from gammaIFN. CpG residues are not responsible for this effect, and the action of the ds polynucleotides could be shown in a variety of cell types in addition to thyrocytes. We suggest that this phenomenon is a plausible mechanism that might explain how viral infection of tissues or tissue injury triggers autoimmune disease; it is potentially relevant to host immune responses induced during gene therapy.


Assuntos
DNA Viral/imunologia , Regulação da Expressão Gênica/imunologia , Complexo Principal de Histocompatibilidade , Simplexvirus/imunologia , Células 3T3 , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Genes MHC Classe I , Genes MHC da Classe II , Interferon gama/imunologia , Camundongos , NF-kappa B/metabolismo , RNA de Cadeia Dupla/imunologia , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT1 , Fator de Transcrição STAT3 , Glândula Tireoide , Transativadores/metabolismo , Transfecção , Proteínas da Matriz Viral/imunologia
17.
J Immunol ; 161(5): 2325-32, 1998 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-9725227

RESUMO

Using the murine parasite Plasmodium yoelii (Py) as a model for malaria vaccine development, we have previously shown that a DNA plasmid encoding the Py circumsporozoite protein (PyCSP) can protect mice against sporozoite infection. We now report that mixing a new plasmid PyCSP1012 with a plasmid encoding murine granulocyte-macrophage colony-stimulating factor (GM-CSF) increases protection against malaria, and we have characterized in detail the increased immune responses due to GM-CSF. PyCSP1012 plasmid alone protected 28% of mice, and protection increased to 58% when GM-CSF was added (p < 0.0001). GM-CSF plasmid alone did not protect, and control plasmid expressing inactive GM-CSF did not enhance protection. GM-CSF plasmid increased Abs to PyCSP of IgG1, IgG2a, and IgG2b isotypes, but not IgG3 or IgM. IFN-gamma responses of CD8+ T cells to the PyCSP 280-288 amino acid epitope increased but CTL activity did not change. The most dramatic changes after adding GM-CSF plasmid were increases in Ag-specific IL-2 production and CD4+ T cell proliferation. We hypothesize that GM-CSF may act on dendritic cells to enhance presentation of the PyCSP Ag, with enhanced IL-2 production and CD4+ T cell activation driving the increases in Abs and CD8+ T cell function. Recombinant GM-CSF is already used in humans for medical purposes, and GM-CSF protein or plasmids may be useful as enhancers of DNA vaccines.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Vacinas Antimaláricas/imunologia , Malária/imunologia , Malária/prevenção & controle , Plasmídeos/imunologia , Plasmodium yoelii/imunologia , Vacinas de DNA/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/genética , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Imunoglobulina G/biossíntese , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/genética , Malária/genética , Vacinas Antimaláricas/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Plasmídeos/farmacologia , Plasmodium yoelii/genética , Plasmodium yoelii/crescimento & desenvolvimento , Vacinas de DNA/genética
18.
J Immunol ; 167(5): 2602-7, 2001 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-11509601

RESUMO

Mature APCs play a key role in the induction of Ag-specific immunity. This work examines whether genomic DNA released by dying cells provides a stimulus for APC maturation. Double-stranded but not single-stranded genomic DNA triggered APC to up-regulate expression of MHC class I/II and various costimulatory molecules. Functionally, dsDNA enhanced APC function in vitro and improved primary cellular and humoral immune responses in vivo. These effects were dependent on the length and concentration of the dsDNA but were independent of nucleotide sequence. The maturation of APC induced by dsDNA may promote host survival by improving immune surveillance at sites of tissue injury/infection.


Assuntos
Células Apresentadoras de Antígenos/citologia , Células Apresentadoras de Antígenos/imunologia , Morte Celular/imunologia , DNA/imunologia , DNA/farmacologia , Animais , Células Apresentadoras de Antígenos/efeitos dos fármacos , Sequência de Bases , Morte Celular/efeitos dos fármacos , Diferenciação Celular , Linhagem Celular , DNA/genética , DNA/metabolismo , Fragmentação do DNA , DNA Bacteriano/genética , DNA Bacteriano/imunologia , DNA Bacteriano/farmacologia , Feminino , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
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