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1.
Front Biosci (Elite Ed) ; 4(7): 2638-46, 2012 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-22652666

RESUMO

Encapsulated bacteria are major pathogens in humans. The capsular polysaccharides (PS) of these bacteria are T-independent type 2 antigens, are not processed by antigen presenting cells and do not induce T cell help. PS antigens are poor immunogens in children less than two years, the peak age incidence of encapsulated bacterial infection. The TNF family receptors BAFFR and TACI interaction with the cytokines BAFF and APRIL are essential co-stimulatory factors for humoral responses to PS. Linkage of PS to a carrier protein to make glycoconjugate vaccines, enhances the immune response to PS similar to a T cell dependent antigen. Multiple doses of glycoconjugate vaccines are required to elicit protection, making their use in the developing world problematic. TLR engagement augments BAFF mediated PS antibody responses and TLR ligands serve as adjuvants for induction of anti-PS antibodies either for pure PS or for PS-protein conjugate vaccines. A variety of TLR ligands stimulate increased production of antibodies directed to both PS and protein components of encapsulated bacteria, and glycoconjugate vaccines, suggesting their future role in immunization strategies.


Assuntos
Anticorpos Antibacterianos/biossíntese , Bactérias/imunologia , Receptores Toll-Like/fisiologia , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular , Humanos , Receptores do Fator de Necrose Tumoral/fisiologia , Receptores Toll-Like/agonistas
2.
Vaccine ; 30(30): 4409-13, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-22575168

RESUMO

Advances in the use of carbohydrates as vaccine candidates for the prevention of infectious and malignant diseases was the topic for a meeting in Rockville, MD, sponsored by the National Institute of Allergy and Infectious Diseases involving a diverse group of scientists. Participants included research scientists and clinicians from academia and industry, and representatives from the National Institutes of Health and US Food and Drug Administration. This workshop was the third in a series of meetings designed to address issues relating to the immune response to carbohydrate antigens and how this information is used in the development of vaccines. Participants also identified roadblocks, research opportunities and resource needs. The meeting was organized into sessions that focused on recent advances in the immune response to microbial and cancer carbohydrate antigens, glycomics, novel vaccine approaches, novel adjuvants and delivery systems.


Assuntos
Carboidratos/imunologia , Vacinas/imunologia , Adjuvantes Imunológicos , Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Glicômica , National Institute of Allergy and Infectious Diseases (U.S.) , National Institutes of Health (U.S.) , Polissacarídeos/imunologia , Estados Unidos , United States Food and Drug Administration
3.
Biol Direct ; 7: 3, 2012 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-22248284

RESUMO

BACKGROUND: Antibodies of the IgG3 subclass have been implicated in the pathogenesis of the spontaneous glomerulonephritis observed in mice of the MRL/MpJ-Tnfrsf6lpr (MRL/lpr) inbred strain which have been widely studied as a model of systemic lupus erythematosus We have produced IgG3-deficient (-/-) mice with the MRL/lpr genetic background to determine whether IgG3 antibodies are necessary for or at least contributory to MRL/lpr-associated nephritis. RESULTS: The gamma3 genotype (+/+ vs. +/- vs. -/-) did not appear to significantly affect serum titers of IgG auto-antibodies specific for double-stranded DNA (dsDNA) or α-actinin. However, while substantial serum titers of IgG3 auto-antibodies specific for double-stranded DNA (dsDNA) or α-actinin were seen in gamma3 +/+ mice, somewhat lower serum titers of these IgG3 auto-antibodies were found in gamma3 +/- mice, and gamma3 -/- mice exhibited baseline concentrations of these auto-antibodies. Analysis of immunoglobulins eluted from snap-frozen kidneys obtained from mice of all three gamma3 genotypes at ~18 weeks of age revealed much higher quantities of IgG in the kidneys from gamma3 +/+ than gamma3 -/- mice, and most IgG eluted from +/+ mice was IgG3. The serum creatinine levels in gamma3 +/+ mice substantially exceeded those of age-matched gamma3 -/- mice after ~21 weeks of age. Histopathological examination of kidneys from mice sacrificed at pre-determined ages also revealed more extensive glomerulosclerosis in gamma3 +/+ or +/- mice than in -/- mice beginning at 21 weeks of age. Survival analysis for IgG3-deficient and IgG3-producing MRL/lpr mice revealed that gamma3 -/- mice lived significantly longer (p = 0.0006) than either gamma3 +/- or +/+ mice. Spontaneous death appeared to be due to irreversible renal failure, because > 85% of glomeruli in kidneys from mice that died spontaneously were obliterated by glomerulosclerosis. CONCLUSIONS: The available evidence suggests that IgG3 deficiency partially protects MRL/lpr mice against glomerulonephritis-associated morbidity and mortality by slowing or arresting the progression to glomerulosclerosis.


Assuntos
Progressão da Doença , Glomerulonefrite/patologia , Imunoglobulina G/imunologia , Longevidade , Actinina/genética , Actinina/imunologia , Fatores Etários , Alelos , Animais , Autoanticorpos/sangue , Autoanticorpos/imunologia , Creatinina/sangue , Creatinina/urina , DNA/genética , DNA/imunologia , Feminino , Genótipo , Glomerulonefrite/sangue , Glomerulonefrite/genética , Glomerulonefrite/imunologia , Imunoglobulina G/análise , Imunoglobulina G/sangue , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/patologia , Endogamia , Rim/citologia , Rim/imunologia , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Polimorfismo de Nucleotídeo Único , Análise de Sobrevida
4.
Clin Vaccine Immunol ; 18(5): 724-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21450979

RESUMO

Bacterial polysaccharides (PS) are T cell-independent antigens that do not induce immunologic memory and are poor immunogens in infants. Conjugate vaccines in which the PS is covalently linked to a carrier protein have enhanced immunogenicity that resembles that of T cell-dependent antigens. The Haemophilus influenzae type b (Hib) conjugate vaccine, which uses the outer membrane protein complex (OMPC) from meningococcus as a carrier protein, elicits protective levels of anti-capsular PS antibody (Ab) after a single dose, in contrast to other conjugate vaccines, which require multiple doses. We have previously shown that OMPC robustly engages Toll-like receptor 2 (TLR2) and enhances the early anti-Hib PS Ab titer associated with an increase in TLR2-mediated induction of cytokines. We now show that the addition of OMPC to the 7-valent pneumococcal PS-CRM197 conjugate vaccine during immunization significantly increases the anti-PS IgG and IgM responses to most serotypes of pneumococcus contained in the vaccine. The addition of OMPC also increased the likelihood of anti-PS IgG3 production against serotypes 4, 6B, 9V, 18C, 19F, and 23F. Splenocytes from mice who had received OMPC with the pneumococcal conjugate vaccine produced significantly more interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) than splenocytes from mice who received phosphate-buffered saline (PBS) plus the conjugate vaccine. We conclude that OMPC enhances the anti-PS Ab response to pneumococcal PS-CRM197 conjugate vaccine, an effect associated with a distinct change in cytokine profile. It may be possible to reduce the number of conjugate vaccine doses required to achieve protective Ab levels by priming with adjuvants that are TLR2 ligands.


Assuntos
Anticorpos Antibacterianos/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Pneumocócicas/imunologia , Animais , Citocinas/metabolismo , Feminino , Vacina Pneumocócica Conjugada Heptavalente , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Leucócitos Mononucleares/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Baço/imunologia
5.
Vaccine ; 27(24): 3137-44, 2009 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-19446183

RESUMO

Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.


Assuntos
Apresentação de Antígeno , Proteínas de Bactérias/imunologia , Antígenos de Histocompatibilidade Classe II/análise , Vacinas Pneumocócicas/imunologia , Polissacarídeos/metabolismo , Animais , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Polissacarídeos/análise , Polissacarídeos/imunologia , Linfócitos T/imunologia , Vacinas Conjugadas/imunologia
6.
Blood ; 110(8): 2948-54, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17634409

RESUMO

Neonates have an increased rate of infection with encapsulated bacteria compared with older children and adults because of diminished antibody responses to T-independent (TI) antigens such as bacterial polysaccharides. Because the interactions of tumor necrosis factor (TNF) family ligands BAFF and APRIL with the TNF family receptors (TNFRs) TACI, BCMA, and BAFF-R are crucial to TI antibody responses, we measured the expression of these receptors on adult and cord blood-derived term and preterm neonatal B cells. Preterm neonatal B cells expressed less TACI, BCMA, and BAFF-R compared with adult B cells and had significantly less proliferation compared with adult B cells after stimulation with human recombinant BAFF and anti-IgM in an assay in which TACI-Fc fusion protein inhibits B-cell proliferation. In addition, neonatal dendritic cells had diminished expression of B7-1, B7-2, and CD40 compared with adult cells. Finally, neonatal B cells, particularly preterm B cells, exhibited markedly decreased production of IgG and IgA in response to CD40L and IL-10. Overall, this study shows that maturational delay in TNFR expression particularly by preterm neonatal B cells may interfere with effective antibody responses to TI antigens, cognate T- and B-cell interactions and normal isotype switching.


Assuntos
Formação de Anticorpos/fisiologia , Linfócitos B/metabolismo , Expressão Gênica , Recém-Nascido Prematuro/imunologia , Receptores do Fator de Necrose Tumoral/biossíntese , Adulto , Fator Ativador de Células B/metabolismo , Linfócitos B/imunologia , Proliferação de Células , Células Dendríticas/imunologia , Ensaio de Imunoadsorção Enzimática , Sangue Fetal , Citometria de Fluxo , Humanos , Imunoglobulina A/biossíntese , Imunoglobulina G/biossíntese , Recém-Nascido , Ativação Linfocitária/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia , Membro 13 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo
7.
Antimicrob Agents Chemother ; 51(9): 3322-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17606688

RESUMO

The production of a recombinant human IgG1 in transgenic tobacco was examined to determine whether a plant-derived antibody could recruit immune system effector function against a bacterial pathogen. A plant transformation vector was engineered to contain genes for a human kappa light chain and a human gamma-1 heavy chain with V(H) and V(L) sequences from a previously identified human IgG2 monoclonal antibody (MAb) that specifically binds to and opsonizes Pseudomonas aeruginosa serotype O6ad. Unique NcoI and NotI restriction sites were incorporated to flank these variable sequences, resulting in a plant transformation vector that could be engineered for expression of any other human IgG1 antibody, requiring only the substitution of other V(H) and V(L) antigen-binding coding sequences. The plant-produced IgG1 was determined to have high-mannose glycan content and to be capable of mediating opsonophagocytosis of P. aeruginosa serotype O6ad in vitro using human complement and human polymorphonuclear leukocytes. Thus, MAbs produced in plants from this vector could provide human IgG1 MAbs for targeting other pathogens that require the recruitment of immune system effector functions.


Assuntos
Sistema Imunitário/efeitos dos fármacos , Sistema Imunitário/imunologia , Imunoglobulina G/genética , Imunoglobulina G/farmacologia , Nicotiana/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Pseudomonas aeruginosa/imunologia , Anticorpos Monoclonais/química , Retículo Endoplasmático/metabolismo , Vetores Genéticos , Humanos , Imunoglobulina G/biossíntese , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/imunologia , Técnicas In Vitro , Manose/metabolismo , Dados de Sequência Molecular , Neutrófilos/efeitos dos fármacos , Proteínas Opsonizantes/farmacologia , Fagocitose/efeitos dos fármacos , Polissacarídeos/imunologia , Polissacarídeos/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia
8.
Pediatr Clin North Am ; 53(4): 699-713, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16873000

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging bacterial infection worldwide, and community-acquired MRSA (CA-MRSA) infection, which has increased dramatically in frequency in many areas, is of particular clinical and public health concern. CA-MRSA outbreaks and severe infections have been reported more frequently in children, often manifesting in one of two distinct clinical syndromes, furunculosis or necrotizing pneumonia. This article outlines the molecular biology of MRSA, how molecular biology has contributed to the understanding of MRSA infections, current therapy and prevention of MRSA, and the prospects for a vaccine against S aureus.


Assuntos
Antibacterianos/uso terapêutico , Resistência a Meticilina/fisiologia , Infecções Estafilocócicas/tratamento farmacológico , Vacinas Antiestafilocócicas , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/prevenção & controle , Humanos , Resistência a Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/efeitos dos fármacos
9.
Vaccine ; 23(25): 3264-71, 2005 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-15837231

RESUMO

Pseudomonas aeruginosa is a serious human pathogen in a variety of patient groups including those with burns, hospitalized in intensive care, cystic fibrosis and neutropenia. Since there is no vaccine available, passive antibody prophylaxis against protective epitopes is an alternative strategy to prevent P. aeruginosa infection. However, immunoglobulin derived from multiple donors has variable anti-pseudomonas antibody titers, and human Mab are difficult to make from patient samples. We previously reported the use of XenoMouse mice, Ig-inactivated transgenic mice reconstituted with human immunoglobulin loci, to generate human Mab against a single serotype of P. aeruginosa lipopolysaccharide O-specific side chain (PS). We now report the creation of a panel of anti-PS human IgG2 Mab against nine additional O-specific side chain P. aeruginosa serotypes. The majority of the Mab were highly opsonic for uptake and killing of homologous P. aeruginosa by human PMN in the presence of human complement, and all the Mab protected cyclophosphamide-induced neutropenic mice from fatal P. aeruginosa sepsis with homologous serotypes. DNA sequence analysis showed that the Mab used V(H)3, V(H)4, V(H)5 and V(H)6 and Vkappa2, 3 and 4 variable region genes consistent with the heterogeneity of P. aeruginosa LPS O-side chain structure. We conclude that human Mab made in these transgenic mice against common pathogenic serotypes of P. aeruginosa are opsonic and highly protective, and that a high titer, multi-valent human Mab preparation against the majority of circulating O-side chain serotypes of P. aeruginosa could be used as prophylaxis against invasive infections in selected patient groups.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Imunoglobulinas/genética , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/imunologia , Animais , Ciclofosfamida , Ensaio de Imunoadsorção Enzimática , Humanos , Imunização , Imunoglobulina G/imunologia , Imunoglobulinas/imunologia , Imunossupressores , Lipopolissacarídeos/metabolismo , Camundongos , Camundongos Transgênicos , Peso Molecular , Neutropenia/induzido quimicamente , Neutropenia/complicações , Infecções por Pseudomonas/imunologia , Sepse/microbiologia , Sepse/prevenção & controle
10.
Infect Immun ; 72(6): 3315-24, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15155635

RESUMO

Citrobacter rodentium, a murine model pathogen for human enteropathogenic Escherichia coli, predominantly colonizes the lumen and mucosal surface of the colon and cecum and causes crypt hyperplasia and mucosal inflammation. Mice infected with C. rodentium develop a secretory immunoglobulin A (IgA) response, but the role of B cells or secretory antibodies in host defense is unknown. To address this question, we conducted oral C. rodentium infections in mice lacking B cells, IgA, secreted IgM, polymeric Ig receptor (pIgR), or J chain. Normal mice showed peak bacterial numbers in colon and feces at 1 week and bacterial eradication after 3 to 4 weeks. B-cell-deficient mice were equally susceptible initially but could not control infection subsequently. Tissue responses showed marked differences, as infection of normal mice was accompanied by transient crypt hyperplasia and mucosal inflammation in the colon and cecum at 2 but not 6 weeks, whereas B-cell-deficient mice had few mucosal changes at 2 weeks but severe epithelial hyperplasia with ulcerations and mucosal inflammation at 6 weeks. The functions of B cells were not mediated by secretory antibodies, since mice lacking IgA or secreted IgM or proteins required for their transport into the lumen, pIgR or J chain, cleared C. rodentium normally. Nonetheless, systemic administration of immune sera reduced bacterial numbers significantly in normal and pIgR-deficient mice, and depletion of IgG abrogated this effect. These results indicate that host defense against C. rodentium depends on B cells and IgG antibodies but does not require production or transepithelial transport of IgA or secreted IgM.


Assuntos
Linfócitos B/imunologia , Citrobacter rodentium/patogenicidade , Infecções por Enterobacteriaceae/imunologia , Imunoglobulina A Secretora/biossíntese , Imunoglobulina M/biossíntese , Animais , Ceco/imunologia , Ceco/microbiologia , Colo/imunologia , Colo/microbiologia , Infecções por Enterobacteriaceae/microbiologia , Humanos , Imunoglobulina A Secretora/imunologia , Imunoglobulina G/biossíntese , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
11.
J Immunol ; 172(4): 2431-8, 2004 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-14764714

RESUMO

Conjugate vaccines consisting of the capsular polysaccharide (PS) of Haemophilus influenzae type b (Hib) covalently linked to carrier proteins, unlike pure PS, are immunogenic in infants and have significantly reduced Hib infections in the United States, but require multiple doses to induce protective anti-PS Ab titers. Hib-meningococcal outer membrane protein complex (OMPC) conjugate vaccine, however, elicits protective anti-PS Ab titers after one dose. We found that OMPC and Hib-OMPC engaged human Toll-like receptor 2 (TLR2) expressed in human embryonic kidney (HEK) cells, inducing IL-8 production, and engaged mouse TLR2 on bone marrow-derived dendritic cells, inducing TNF release. Hib conjugated to the carrier proteins CRM(197) and tetanus toxoid did not engage TLR2 on HEK or dendritic cells. Engagement of TLR2 by Hib-OMPC was MyD88 dependent, as Hib-OMPC-induced TNF production was ablated in MyD88 knockout (KO) mice. Hib-OMPC was significantly less immunogenic in TLR2 KO mice, inducing lower Hib PS IgG and IgM titers compared with those in wild-type mice. Splenocytes from OMPC-immunized TLR2 KO mice also produced significantly less IL-6 and TNF-alpha than those from wild-type mice. Hib-OMPC is unique among glycoconjugate vaccines by engaging TLR2, and the ability of Hib-OMPC to elicit protective levels of Abs after one dose may be related to TLR2-mediated induction and regulation of cytokines produced by T cells and macrophages in addition to the peptide/MHC II-dependent recruitment of T cell help commonly afforded by carrier proteins. TLR2 engagement by an adjuvant or carrier protein may be a useful strategy for augmentation of the anti-PS Ab response induced by glycoconjugate vaccines.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Citocinas/biossíntese , Vacinas Anti-Haemophilus/imunologia , Glicoproteínas de Membrana/fisiologia , Neisseria meningitidis/imunologia , Polissacarídeos Bacterianos/imunologia , Receptores de Superfície Celular/fisiologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/sangue , Antígenos de Diferenciação/fisiologia , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Proteínas de Transporte/administração & dosagem , Linhagem Celular , Células Cultivadas , Células Dendríticas , Regulação para Baixo/genética , Regulação para Baixo/imunologia , Vacinas Anti-Haemophilus/administração & dosagem , Humanos , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 88 de Diferenciação Mieloide , Polissacarídeos Bacterianos/administração & dosagem , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/deficiência , Receptores de Superfície Celular/genética , Receptores Imunológicos/fisiologia , Receptor 2 Toll-Like , Receptores Toll-Like , Fator de Necrose Tumoral alfa/metabolismo , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologia
12.
J Immunol Methods ; 281(1-2): 129-42, 2003 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-14580887

RESUMO

The study of antigen processing and presentation by human antigen presenting cells (APC) has been limited by difficulties of producing and maintaining human T-cell clones. Murine T-cell hybridomas have advantages for detecting specific peptide-MHC complexes on APC. Human antigen-specific immortalized T-cell lines have not been successfully produced. We report and validate the use of transgenic mice with human MHC genes for HLA-A2, DR1 and DR4 to produce murine T-cell hybridomas that are restricted to human HLA alleles and respond to human macrophages, dendritic cells (DC), and B-cell lines. Hybridomas restricted by human MHC-I and -II specific for influenza matrix protein, tetanus toxoid, diphtheria antigen CRM(197), and various M. tuberculosis antigens were produced. Epitope specificity was determined for several hybridomas. T hybridomas recognized peptide-MHC complexes on fixed APC for analysis of kinetics or susceptibility to inhibitors of antigen processing. T hybridomas restricted by human MHC represent convenient and powerful tools for the study of antigen processing by human APC.


Assuntos
Apresentação de Antígeno , Antígeno HLA-A2/fisiologia , Hibridomas/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Células Apresentadoras de Antígenos/fisiologia , Linhagem Celular , Mapeamento de Epitopos , Humanos , Interferon gama/farmacologia , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular
13.
Pediatrics ; 112(1 Pt 1): e61-5, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12837907

RESUMO

A cluster of 5 family members, a mother and 4 children, were hospitalized for severe group A Streptococcus (GAS) pneumonia. Three family members had complications: sepsis (1), empyema (2), and a sterile parapneumonic effusion (1). Two additional family members had symptoms of upper respiratory tract infection, and 1 was hospitalized for these symptoms. GAS was isolated from the blood of 1 patient, the pleural fluid of 2 patients, and the oropharynx of 6 patients. Pulsed field gel electrophoresis testing revealed an identical deoxyribonucleic acid pattern in all 7 isolates. Genotyping revealed the speA gene and serotyping the T-1, M-1 serotype in all isolates. This family cluster of invasive GAS disease is the largest reported to date, with an attack rate of 41.7% (5 of 12 family members). This report provides further support for antibiotic prophylaxis of close contacts of individuals with invasive GAS disease.


Assuntos
Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/isolamento & purificação , Antibacterianos , Criança , Busca de Comunicante , DNA Bacteriano/análise , Surtos de Doenças , Transmissão de Doença Infecciosa/prevenção & controle , Quimioterapia Combinada/uso terapêutico , Eletroforese em Gel de Campo Pulsado , Empiema Pleural/tratamento farmacológico , Empiema Pleural/microbiologia , Empiema Pleural/cirurgia , Saúde da Família , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Faringite/microbiologia , Pneumonia Bacteriana/microbiologia , Sorotipagem , Choque Séptico/microbiologia , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/cirurgia , Infecções Estreptocócicas/transmissão , Streptococcus pyogenes/classificação , Streptococcus pyogenes/genética
14.
Infect Immun ; 71(7): 4186-9, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12819115

RESUMO

The pneumococcal (Pn) conjugate vaccine includes seven different polysaccharides (PS) conjugated to CRM(197). Utilizing antigen-processing cells and a CRM(197)-specific mouse T-cell hybridoma, we found that the serotype of conjugated PnPS dramatically affected antigen processing of CRM(197). Unconjugated CRM(197) and serotype conjugates 14 and 18C were processed more efficiently.


Assuntos
Apresentação de Antígeno , Proteínas de Bactérias/metabolismo , Vacinas Pneumocócicas/administração & dosagem , Polissacarídeos Bacterianos/administração & dosagem , Vacinas Conjugadas/administração & dosagem , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/administração & dosagem , Antígeno HLA-DR1/fisiologia , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Sorotipagem , Linfócitos T/imunologia
15.
J Infect Dis ; 187(10): 1629-38, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12721943

RESUMO

Streptococcus pneumoniae capsular polysaccharides (PnPSs) induce protective antibodies but are T cell-independent type 2 antigens and are poorly immunogenic in infants. Conjugate vaccines of PnPSs linked to proteins like cross-reactive material (CRM(197)) increase PS antibody titer and elicit immunologic memory in infants. Despite being linked to an identical carrier protein, each PS component of the 7-valent PnPS-CRM(197) vaccine has different immunogenicity. To determine whether variations in conjugate-induced memory T cell responses or PnPS-specific antibody-secreting cells (ASCs) were responsible for serotype-specific differences in immunogenicity, adults were immunized with 7-valent PnPS-CRM(197), and antibody titer, vaccine component-specific CD4(+) T cell recall response, numbers of PnPS-specific ASCs, and cytokine production were measured. PnPS-CRM(197) induced significantly different serotype-specific antibody titers, despite vigorous T cell recall responses to all 7 vaccine components, and production of interleukin (IL)-2, IL-5, IL-6, IL-10, and interferon-gamma. We conclude that PnPS-CRM(197) induces variable serotype-specific antibody titers, despite induction of comparable CRM(197)-specific memory T cell responses.


Assuntos
Antígenos de Bactérias/imunologia , Cápsulas Bacterianas/imunologia , Proteínas de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Vacinas Conjugadas/imunologia , Adulto , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Citocinas/imunologia , Feminino , Humanos , Memória Imunológica , Masculino , Sorotipagem , Células Th1/imunologia , Células Th2/imunologia , Fatores de Tempo
17.
Infect Immun ; 70(10): 5589-95, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12228286

RESUMO

Immunization of mice with pneumococcal surface adhesin A (PsaA) emulsified in complete Freund's adjuvant (CFA) provides protection against systemic infection with Streptococcus pneumoniae. Because the use of CFA is not acceptable in humans, we sought to develop alternative means of enhancing the immunogenicity of protein antigens of potential use in pneumococcal vaccines. We designed a series of genetic constructs in which coding sequences for PsaA were linked to sequences encoding either murine interleukin-2 (mIL-2), mIL-4, or two copies of an immunostimulatory nonapeptide derived from mIL-1beta. The PsaA-cytokine constructs were cloned and expressed in Escherichia coli. Mice immunized twice with PsaA-IL-2, or PsaA-IL-4 responded with PsaA-specific antibody production comparable in magnitude to that of mice primed with PsaA in CFA and boosted with PsaA in incomplete Freund's adjuvant (PsaA-Adj). Antibodies elicited by PsaA-Adj were predominantly of the immunoglobulin G1 (IgG1) subclass, while PsaA-IL-2 and PsaA-IL-4 elicited substantial amounts of IgG2a in addition to IgG1. Mice immunized with PsaA-Adj or PsaA-IL-4 were partially protected against intraperitoneal challenge with virulent S. pneumoniae (30% overall survival beyond 15 days postchallenge). Mice immunized with PsaA and no adjuvant or PsaA-IL-2 exhibited 0 or 5% survival rates, respectively, following challenge. In contrast, mice immunized twice with capsular polysaccharide were 100% protected. The modest levels of protection seen in mice immunized with PsaA and its more immunogenic derivatives may be explained in part by the relative inaccessibility of antibody to PsaA on the surface of encapsulated S. pneumoniae.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Citocinas/genética , Lipoproteínas/genética , Lipoproteínas/imunologia , Proteínas de Membrana Transportadoras , Adesinas Bacterianas , Animais , Anticorpos Antibacterianos/metabolismo , Fusão Gênica Artificial , Aderência Bacteriana , Sequência de Bases , DNA Recombinante/genética , Técnica Indireta de Fluorescência para Anticorpo , Interleucina-2/genética , Interleucina-4/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos CBA , Dados de Sequência Molecular , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/genética , Vacinas Pneumocócicas/farmacologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Vacinas Sintéticas/genética , Vacinas Sintéticas/farmacologia
18.
J Immunol ; 168(7): 3437-43, 2002 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11907102

RESUMO

Bacterial polysaccharides (PS) are type 2 T-independent Ags that elicit Abs restricted in isotype to IgM and predominantly IgG2 in humans and IgM, and IgG3 in mice. Humans with IgG2 subclass deficiency are susceptible to sinus and pulmonary infections with PS-encapsulated bacteria. We previously developed an IgG3-deficient mouse by disrupting the gamma3 H chain constant region gene via targeted mutagenesis. Mutant mice lacking IgG3 were backcrossed for 10 generations to wild-type (WT) BALB/c mice to generate BALB/c mice that have complete absence of IgG3. WT mice immunized with type 3 Streptococcus pneumoniae capsular PS made anti-PS IgM, IgG3, and small quantities of IgG1, which opsonized S. pneumoniae for killing by polymorphonuclear leukocytes. These mice were protected against death from lethal doses of type 3 S. pneumoniae. In contrast, IgG3(-/-) mice made similar titers of anti-PS IgM and IgG1 as WT mice but no IgG3, and had poorly opsonic sera with significantly increased mortality after S. pneumoniae challenge. Immunization of IgG3(-/-) mice with type 3 S. pneumoniae PS conjugated to carrier protein CRM(197)-elicited IgM and high-titer IgG1 Abs, restored serum opsonization, and gave protection from mortality after S. pneumoniae, challenge comparable to WT mice. We conclude that mice lacking the dominant IgG3 subclass made to bacterial PS are more susceptible to fatal S. pneumoniae sepsis than WT mice, but that IgG1 induced by a S. pneumoniae glycoconjugate can adequately protect against S. pneumoniae sepsis. This model suggests that IgG subclass of anti-PS Ab is an important component of immunity to encapsulated bacteria.


Assuntos
Genes de Imunoglobulinas , Predisposição Genética para Doença , Deficiência de IgG/genética , Imunoglobulina G/biossíntese , Imunoglobulina G/genética , Pneumonia Pneumocócica/genética , Pneumonia Pneumocócica/imunologia , Polissacarídeos Bacterianos/imunologia , Alelos , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/genética , Cápsulas Bacterianas , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Feminino , Genótipo , Deficiência de IgA/genética , Deficiência de IgA/imunologia , Deficiência de IgG/imunologia , Soros Imunes/administração & dosagem , Imunização Passiva , Imunoglobulina G/classificação , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Opsonizantes/farmacologia , Fenótipo , Pneumonia Pneumocócica/mortalidade , Pneumonia Pneumocócica/prevenção & controle , Polissacarídeos Bacterianos/administração & dosagem , Sepse/genética , Sepse/imunologia , Sepse/mortalidade , Streptococcus pneumoniae/crescimento & desenvolvimento , Streptococcus pneumoniae/imunologia , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologia
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