RESUMO
Although Mycoplasma pneumonia infection is relatively common among school-aged children, it rarely leads to SJS. Herein, we report a seven-yr-old girl who presented with a Mycoplasma pneumonia infection that progressed to SJS five months after liver transplant. We suggest that children presenting with symptoms of Mycoplasma pneumonia infection in the immunosuppressed post-liver transplant setting be properly diagnosed and treated rapidly, as well as observed for symptoms of SJS and potentially serious extrapulmonary complications.
Assuntos
Transplante de Fígado/efeitos adversos , Mycoplasma pneumoniae/metabolismo , Pneumonia por Mycoplasma/complicações , Pneumonia por Mycoplasma/diagnóstico , Síndrome de Stevens-Johnson/complicações , Síndrome de Stevens-Johnson/diagnóstico , Biópsia , Vesícula , Criança , Comorbidade , Feminino , Humanos , Falência Hepática/complicações , Falência Hepática/terapia , Pneumonia por Mycoplasma/microbiologia , Complicações Pós-OperatóriasRESUMO
Rejection is independently associated with liver graft loss in children. We report the successful rescue of grafts using ATG+/-OKT3 in late rejection associated with cholestasis. Retrospective chart review was performed after IRB approval. Between 2003 and 2010, 14 pediatric liver transplant recipients received anti-lymphocyte treatment for "cholestatic" rejection. Median age at transplantation was 12.7 yr (range 0.9-23.4), eight were boys, and immunosuppression was tacrolimus based. Median time from transplantation to rejection was five yr (range 1.1-10.5). Median peak total bilirubin was 11.1 mg/dL (range 1.4-18). All showed moderate to severe acute rejection and hepatocellular cholestasis on histology. ATG/OKT3 was started as first-line therapy in six and in the remaining eight as second-line therapy after failure of pulse steroids. Thirteen responded with normalization of aminotransferases and bilirubin, median time 16 wk (range 7-112); one non-adherent recipient has still not achieved normal graft function at last follow-up. Patient survival is 100%, with no re-transplantation and no post-transplant lymphoproliferative disease, median follow-up 2.9 yr (range 1.1-7.2). Cholestasis associated with acute rejection occurring late after liver transplantation may herald steroid resistance. First-line therapy with anti-lymphocyte preparations, prophylactic anti-microbial therapy, and close monitoring allow excellent rates of patient and graft survival.
Assuntos
Soro Antilinfocitário/uso terapêutico , Colestase/prevenção & controle , Rejeição de Enxerto/prevenção & controle , Imunossupressores/uso terapêutico , Transplante de Fígado/efeitos adversos , Muromonab-CD3/uso terapêutico , Adolescente , Adulto , Criança , Pré-Escolar , Colestase/etiologia , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Lactente , Masculino , Prognóstico , Estudos Retrospectivos , Tacrolimo/uso terapêutico , Adulto JovemRESUMO
Rett syndrome (RTT) is an X-linked dominant postnatal severe and disabling neurodevelopmental disorder which is the second most common cause for genetic mental retardation in girls and the first pervasive disorder with a known genetic basis. The syndrome is primarily caused by mutations in the Methyl CpG binding protein 2 (MECP2) gene on Xq28. Its protein product MeCP2 acts as a transcriptional repressor or activator depending on the target gene associated. Brain derived neurotrophic factor (BDNF) is a neurotrophic factor playing a major role in neuronal survival, neurogenesis and plasticity. It has been identified as a major MeCP2 target through a candidate gene approach and abnormalities in BDNF homeostasis are believed to contribute to the neurologic phenotype and pato-physiology of part of the symptoms in Mecp2 null mice that show progressive deficits in its expression. Based on the presumed role of BDNF in the pathophysiology of Rett syndrome it is reasonable to assume that interventions that will elevate its levels in the brain of RTT patients will be of therapeutic benefit. Glatiramer acetate (GA, Copolymer 1, Copaxone) an immunomodulator with proven safety and efficacy in Multiple Sclerosis has been reported to cause elevated secretion of BDNF both in animal model and in MS patients. Our hypothesis is that continuous treatment of patients with RTT with Glatiramer acetate might lead to an increase in their brain's BDNF content and an improvement in at least part of the syndrome symptomatology while being safe to use and well tolerated in this population. In a pilot preliminary study we have shown that GA cause elevation of BDNF expression up to the level in naïve control mice in several cortical areas in the Mecp2 mutated mouse brain, but as of yet did not examine the behavioral aspects of this elevation.
Assuntos
Peptídeos/uso terapêutico , Síndrome de Rett/tratamento farmacológico , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Feminino , Acetato de Glatiramer , Humanos , Fatores Imunológicos/uso terapêutico , Masculino , Proteína 2 de Ligação a Metil-CpG/genética , Camundongos , Camundongos Transgênicos , Modelos Biológicos , Mutação , Transcrição GênicaRESUMO
Glatiramer acetate (GA) previously known as Copolymer 1 (Cop 1), a synthetic amino acid copolymer, suppresses experimental autoimmune encephalomyelitis (EAE) and shows a beneficial effect in relapsing-remitting type of multiple sclerosis (MS). GA acts as a specific immunomodulator by binding to MHC Class II molecules, inducing specific T suppressor (Ts) cells and interfering with T cell responses to myelin antigens. MS patients treated with GA developed GA reactive antibodies, which peaked at three months and decreased at six months. In order to find out whether anti-GA antibodies may neutralize the therapeutic effect of GA, we tested both polyclonal (mouse and human) and monoclonal GA specific antibodies for their ability to interfere with the biological activity of GA in several assay systems. None of the antibodies interfered with GA activities either in vitro (binding to MHC molecules and T cell stimulation) or in vivo (blocking of EAE). Furthermore, 53 samples of sera obtained from 34 MS patients that participated in the open label trial in Israel, and all developed GA specific antibodies, were tested for their ability to inhibit the proliferation response of GA specific Ts cell clone and to interfere with GA competitive inhibition of the response to peptide 84-102 of myelin basic protein (MBP). None of the sera inhibited and some even enhanced the in vitro activities of GA. Furthermore, representative MS sera with high titer of GA reactive antibodies did not neutralize the biological activities of GA and did not inhibit Th2 cytokine secretion by human GA specific clone. These results are consistent with the findings that the therapeutic effect of GA is not affected by GA reactive antibodies and is sustained upon long term treatment.
Assuntos
Imunossupressores/administração & dosagem , Imunossupressores/imunologia , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/imunologia , Peptídeos/administração & dosagem , Peptídeos/imunologia , Animais , Anticorpos Monoclonais , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Feminino , Acetato de Glatiramer , Humanos , Imunoglobulina G/sangue , Camundongos , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: Copolymer 1 (Cop 1) was previously shown to prevent graft-versus-host disease and interfere in various manifestations of immune rejection. In this study, we tested whether Cop 1 can also hinder the reactivity of host against graft and inhibit graft rejection. METHODS: Cop 1 was tested in two transplantation systems: skin and thyroid grafting assays. The effect of Cop 1 on T cell reactivity was investigated by proliferation and cytokine secretion of spleen and lymph node cells from transplanted mice, as well as the T cell lines generated therefrom. RESULTS: Cop 1 treatment prolonged skin graft survival and inhibited the functional deterioration of thyroid grafts, in various strain combinations, across minor and major histocompatibility barriers, similarly to the potent immunosuppressive drug FK506. Cop 1 inhibited the proliferation of graft-specific T cell lines, as well as their interleukin (IL)-2 and interferon-gamma (IFN-gamma) secretion, when incubated in vitro with the stimulating allogeneic cells. Spleen and lymph node cells from Cop 1-treated mice, as well as the T cell lines generated from them, demonstrated a pronounced inhibition of proliferation and secretion of T helper (Th)1 cytokines in response to graft cells. In addition, cells from Cop 1-treated mice secreted high amounts of Th2 cytokines in response to Cop 1 and small but significant amounts of Th2 cytokines, mainly IL-10, in response to allograft cells. CONCLUSIONS: Cop 1 treatment inhibited the Th1 response to graft and induced a Th2 cytokines secretion in response to both Cop 1 and graft cells, leading to improved survival and function of the transplanted grafts.
Assuntos
Rejeição de Enxerto/prevenção & controle , Reação Hospedeiro-Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Peptídeos/uso terapêutico , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Citocinas/antagonistas & inibidores , Citocinas/metabolismo , Acetato de Glatiramer , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos , Transplante de Pele/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Células Th1/efeitos dos fármacos , Células Th1/metabolismo , Células Th1/patologia , Células Th2/metabolismo , Glândula Tireoide/transplante , Imunologia de TransplantesRESUMO
Humoral and cellular immune responses were followed in multiple sclerosis patients treated with Copolymer 1 (Cop1, glatiramer acetate, Copaxone) who participated in three different clinical trials. All patients (130) developed Cop1 reactive antibodies, which peaked at 3 months after initiation of treatment, decreasing at 6 months and remaining low. IgG1 antibody levels were 2-3-fold higher than those of IgG2. The proliferative response of Peripheral Blood Mononuclear Cells (PBMC) to Cop1 was initially high and gradually decreased during treatment. Antibodies and T cell responses to MBP were low and did not change significantly during the treatment. The humoral and cellular immunological responses to Cop1 do not correlate with the side effects and do not affect its therapeutic activity. The preferential production of IgG1 over IgG2 antibodies may indicate that Th2 responses are involved in mediating the clinical effect of Cop1.
Assuntos
Esclerose Múltipla/tratamento farmacológico , Peptídeos/uso terapêutico , Adulto , Afinidade de Anticorpos/imunologia , Divisão Celular/efeitos dos fármacos , Método Duplo-Cego , Feminino , Acetato de Glatiramer , Humanos , Imunoglobulina G/sangue , Leucócitos Mononucleares/efeitos dos fármacos , Masculino , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Proteína Básica da Mielina/imunologia , Proteína Básica da Mielina/farmacologia , Peptídeos/efeitos adversos , Peptídeos/imunologia , Recidiva , Índice de Gravidade de Doença , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Resultado do TratamentoRESUMO
Synthetic recombinant vaccines are constructs in which a synthetic oligonucleotide coding for a protective epitope is inserted into an adequate gene for expression of the epitope. We report the results obtained using recombinant flagella of Salmonella vaccine strain expressing epitopes of influenza virus or of the parasite Schistosoma mansoni. In the case of influenza virus, three conserved epitopes of the haemagglutinin and the nucleoprotein of the virus inducing B- and T-cell immune response, were expressed and the flagella were used for intranasal immunization without any adjuvant. Both humoral and cellular immune responses specific to the virus induced in mice cross-strain long-term protection against challenge infection. Aged mice were also able to resist infection. For the design of a human influenza vaccine, epitopes recognized by the HLAs prevalent in Caucasian populations were used, and the resulting vaccine was evaluated in human/mouse radiation chimaera in which human PBMC are functionally engrafted. The vaccinated mice demonstrated efficient clearance of the virus after challenge and resistance to lethal infection. In the case of the parasitic disease schistosomiasis, a 14-residue peptide denoted 9B peptide 1 was expressed in the flagella. Intranasal vaccination of mice with this construct, without the use of adjuvant, resulted in 40% protection against challenge infection.
Assuntos
Antivirais/química , Peptídeos/química , Schistosoma mansoni/imunologia , Vacinas Sintéticas/química , Animais , Antivirais/farmacologia , Vírus da Influenza A/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/prevenção & controle , Peptídeos/farmacologia , Salmonella/imunologia , Infecções por Salmonella/prevenção & controle , Esquistossomose/prevenção & controle , Vacinas Sintéticas/farmacologiaRESUMO
A panel of four mimotopes of the epitope recognized by the highly protective monoclonal antibody against Schistosoma mansoni (152-66-9B) was obtained by screening a solid-phase 8mer random peptide library. Three of the four mimotopes (p28, p29 and p30) were efficiently recognized in an in vitro radioimmunoassay by the monoclonal antibody and by sera from infected mice and one (p30) induced in vitro proliferation of primed lymphocytes. When the mimotopes were conjugated to bovine serum albumin (BSA) and the conjugates used to immunize C57BL/6J mice, only the p30-BSA-induced antibodies which were effective at complement-mediated killing of schistosomula. The level of complement-mediated killing obtained with the anti-p30 antibodies was comparable to that seen with serum from mice immunized with the protective 9B-antigen. Furthermore, following challenge infection of mimotope-BSA-immunized mice, a greater than 40% reduction in worm burden was observed in p30-BSA-immunized mice, a level comparable to that seen following immunization with the intact 9B-antigen. These results show that a simple synthetic peptide immunogen comprising an eight-amino acid mimotope of a conformational epitope on the 9B-antigen can induce protective immune responses against S. mansoni that are comparable to those obtained following immunization with the far more complex intact antigen. This mimotope may well represent a potential component of a synthetic peptide vaccine against S. mansoni. The inclusion of other B-cell- and T-cell-stimulating synthetic epitopes in such a vaccine, together with a more appropriate carrier, adjuvant and delivery systems may well result in a level of protection even greater than that seen with the single mimotope.
Assuntos
Mimetismo Molecular/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Vacinas Sintéticas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Anti-Helmínticos/biossíntese , Anticorpos Monoclonais/imunologia , Divisão Celular/imunologia , Proteínas do Sistema Complemento/imunologia , Citotoxicidade Imunológica , Imunização , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Biblioteca de Peptídeos , Vacinas Sintéticas/químicaRESUMO
This study addresses the issue of the effect of immunomodulating therapies in the target organ-the central nervous system (CNS)-in the case of multiple sclerosis. Copolymer 1 (Cop 1, Copaxone, glatiramer acetate), an approved drug for the treatment of multiple sclerosis, is a potent inducer of Th2 regulatory cells in both mice and humans. Highly reactive Cop 1-specific T cell lines that secrete IL-4, IL-5, IL-6, IL-10, and transforming growth factor-beta in response to Cop 1 and crossreact with myelin basic protein (MBP) at the level of Th2 cytokine secretion were established from both brains and spinal cords of Cop 1-treated mice. In contrast, no reactivity to the control antigen lysozyme could be obtained in lymphocytes isolated from CNS of mice injected with lysozyme. Adoptively transferred labeled Cop 1-specific suppressor cells were found in brain sections 7 and 10 days after their injection to the periphery, whereas lysozyme-specific cells were absent in the CNS. Hence, Cop 1-induced Th2 cells cross the blood-brain barrier and accumulate in the CNS, where they can be stimulated in situ by MBP and thereby exert therapeutic effects in the diseased organ. This therapeutic effect was manifested, in brains of experimental autoimmune encephalomyelitis-induced mice, by a decrease in the inflammatory cytokine interferon-gamma and by secretion of the anti-inflammatory cytokine IL-10 in response to the autoantigen MBP.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Sistema Nervoso Central/patologia , Encefalomielite Autoimune Experimental/prevenção & controle , Peptídeos/imunologia , Células Th2/citologia , Transferência Adotiva , Animais , Sistema Nervoso Central/metabolismo , Citocinas/metabolismo , Feminino , Corantes Fluorescentes , Acetato de Glatiramer , Camundongos , Camundongos Endogâmicos BALB C , Muramidase/administração & dosagemRESUMO
Schistosomiasis is the cause of a chronic debilitating disease which accounts for significant mortality and morbidity every year, especially in tropical and subtropical areas. An epitope derived from the protective surface protein 9B-Ag of Schistosoma mansoni, designated 9B peptide-1, was previously showed to be protective in mice when conjugated to bovine serum albumin and administered subcutaneously in complete Freund's adjuvant. In this work, this protective peptide was expressed in the flagellin of a Salmonella vaccine strain, and the isolated recombinant flagella were used for immunization of mice. Since during the invasion of the parasite into the host the schistosomula migrate first to the lungs, the intranasal route of administration was employed in order to halt the parasite at an early stage of the infection. Such intranasal immunization with this peptide expressed in flagellin, without the addition of adjuvants, resulted in a significant humoral response and also led to protection against challenge infection, manifested as a reduction of the worm burden by an average of 42%.
Assuntos
Antígenos de Helmintos/imunologia , Peptídeos/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Vacinas Sintéticas/imunologia , Administração Intranasal , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/administração & dosagem , Antígenos de Helmintos/genética , Antígenos de Helmintos/metabolismo , Biomphalaria , Modelos Animais de Doenças , Flagelina/genética , Flagelina/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/administração & dosagem , Peptídeos/genética , Peptídeos/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/metabolismo , Schistosoma mansoni/genética , Esquistossomose mansoni/parasitologia , Distribuição Tecidual , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologia , Vacinas Sintéticas/administração & dosagemRESUMO
Influenza virus is characterized by frequent and unpredictable changes of the surface glycoproteins which enable the virus to escape the immune system. Approved vaccines which consist of the whole virus or the surface glycoproteins fail to induce broad specificity protection. We have previously reported that a peptide-based experimental recombinant vaccine which includes conserved epitopes of B and T lymphocytes was efficient in mice, leading to cross-strain, long-term protection. In the present study, this approach was adapted for the design of a human vaccine, based on epitopes recognized by the prevalent HLAs. These epitopes were expressed in Salmonella flagellin and tested for their efficacy in human/mouse radiation chimera in which human peripheral blood mononuclear cells (PBMC) are functionally engrafted. The vaccinated mice demonstrated clearance of the virus after challenge and resistance to lethal infection. The production of virus-specific human antibodies was also higher in this group. Control groups of either non-vaccinated, or vaccinated mice which had not been engrafted with the human PBMC, did not exhibit the protective immune response. FACS analysis showed that most human cells in the transplanted mice are CD8(+) and CD4(+). Hence, it may be concluded: (i) that the protection involves cellular mechanisms, but is most probably accomplished without direct lysis of influenza-infected pulmonary cells by cytotoxic T lymphocytes, but rather via a cytokine-mediated mechanism, (ii) that the human/mouse radiation chimera model may be of some value in the investigation of new vaccines, as an additional tool prior to clinical trials, and (iii) that the synthetic recombinant vaccine can induce a response in the human immune system and confers protection against influenza infection. Further investigation is needed to establish the efficacy of such a peptide vaccine in human subjects.
Assuntos
Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Quimera por Radiação/imunologia , Administração Intranasal , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/biossíntese , Humanos , Influenza Humana/imunologia , Influenza Humana/virologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Dados de Sequência Molecular , Vacinas de Produtos Inativados/imunologiaRESUMO
We have previously characterized a stage specific, partially protective protein denoted 9B-antigen. This antigen is of 450 kDa in its native form but upon SDS-PAGE in reducing conditions it exhibits two subunits of 30 kDa and 45 kDa. The 9B-antigen is localized at the surface of schistosomula and persists at the surface of lung schistosomula. The 9B-antigen is also localized in internal organs of a vital function in the parasite such as flame cells and cytoplasmic tubes. Infected individuals or mice vaccinated with irradiated cercariae recognize the 9B-antigen. We have previously shown that when injected with complete Freunds adjuvant, the 9B-antigen can induce 40% protection against challenge infection. In this study we have used a more effective delivery system for this antigen. The 9B-antigen was coupled to proteosomes derived from meningoccocal outer membrane proteins. Vaccination of mice with this complex increased the protection level to 60%. Sera from these vaccinated mice induced high levels of complement mediated cytotoxicity of the parasite. Since the proteosomes are approved for human use, these results are promising towards the development of a vaccine against schistosomiasis.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Antígenos de Helmintos/imunologia , Cisteína Endopeptidases/imunologia , Complexos Multienzimáticos/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Vacinas/imunologia , Animais , Antígenos de Helmintos/administração & dosagem , Antígenos de Helmintos/química , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Doença Crônica , Proteínas do Sistema Complemento/imunologia , Cisteína Endopeptidases/administração & dosagem , Humanos , Soros Imunes/química , Soros Imunes/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Microscopia Imunoeletrônica , Complexos Multienzimáticos/administração & dosagem , Complexo de Endopeptidases do Proteassoma , Schistosoma mansoni/ultraestrutura , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/patologia , Vacinas/administração & dosagem , Vacinas/químicaRESUMO
Copolymer 1 [Cop 1, poly(Y,E,A,K)] is a random synthetic amino acid copolymer of L-tyrosine, L-glutamic acid, L-alanine and L-lysine, effective both in suppression of experimental allergic encephalomyelitis and in the treatment of relapsing forms of multiple sclerosis. Cop 1 binds promiscuously and very efficiently to purified human HLA-DR molecules within the peptide-binding groove. In the present study the binding of copolymers composed of three of the four amino acids found in poly(Y,E,A,K) to purified class II MHC molecules was examined. Poly(Y,A,K) and poly(Y,E,A,K) bound to purified human HLA-DR1 or -DR4 molecules with affinity higher than poly(Y,E,A), poly(E,A,K) or poly(Y,E,K), whereas poly(Y,E,A,K) and poly(E,A,K) were the better binders of HLA-DR2 molecules. On the other hand, poly(Y,E,A) and poly(Y,A,K) inhibited the binding of biotinylated poly(Y,E,A,K) to these molecules 10-fold more efficiently than poly(Y,E,K). Finally, poly(Y,E,A), poly(Y,A,K) and poly(E,A,K) were cross-reactive with poly(Y,E,A,K) using YEAK-specific T cell lines and clones of mouse or human origin.
Assuntos
Antígenos HLA-DR/metabolismo , Peptídeos/metabolismo , Polímeros/metabolismo , Animais , Linhagem Celular , Reações Cruzadas , Acetato de Glatiramer , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/imunologia , Superantígenos/farmacologiaRESUMO
The activity of copolymer 1 (Cop 1, Copaxone, glatiramer acetate) in suppressing experimental autoimmune encephalomyelitis (EAE) and in the treatment of multiple sclerosis patients when injected parenterally has been extensively demonstrated. In the present study we addressed the question of whether Cop 1 can induce oral tolerance to EAE similar to myelin basic protein (MBP). We now have demonstrated that oral Cop 1 inhibited EAE induction in both rats and mice. Furthermore, oral Cop 1 was more effective than oral MBP in suppressing EAE in rats. The beneficial effect of oral Cop 1 was found to be associated with specific inhibition of the proliferative and Th1 cytokine secretion responses to MBP of spleen cells from Cop 1-fed mice and rats. In all of these assays, oral Cop 1 was more effective than oral MBP. The tolerance induced by Cop 1 could be adoptively transferred with spleen cells from Cop 1-fed animals. Furthermore, Cop 1-specific T cell lines, which inhibit EAE induction in vivo, could be isolated from the above spleen cells. These T cell lines secrete the anti-inflammatory cytokines IL-10 and transforming growth factor type beta, but not IL-4, in response to both Cop 1 and MBP. In conclusion, oral Cop 1 has a beneficial effect on the development of EAE that is associated with down-regulation of T cell immune responses to MBP and is mediated by Th2/3 type regulatory cells. These results suggest that oral administration of Cop 1 may modulate multiple sclerosis as well.
Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/imunologia , Imunossupressores/uso terapêutico , Peptídeos/uso terapêutico , Linfócitos T/imunologia , Administração Oral , Transferência Adotiva , Animais , Linhagem Celular , Cruzamentos Genéticos , Citocinas/biossíntese , Feminino , Acetato de Glatiramer , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Peptídeos/administração & dosagem , Ratos , Ratos Endogâmicos Lew , Baço/imunologia , Linfócitos T/efeitos dos fármacosRESUMO
The synthetic random amino acid copolymer Copolymer 1 (Cop 1, Copaxone, glatiramer acetate) suppresses experimental autoimmune encephalomyelitis, slows the progression of disability, and reduces relapse rate in multiple sclerosis (MS). Cop 1 binds to various class II major histocompatibility complex (MHC) molecules and inhibits the T cell responses to several myelin antigens. In this study we attempted to find out whether, in addition to MHC blocking, Cop 1, which is immunologically cross-reactive with myelin basic protein (MBP), inhibits the response to this autoantigen by T cell receptor (TCR) antagonism. Two experimental systems, "prepulse assay" and "split APC assay," were used to discriminate between competition for MHC molecules and TCR antagonism. The results in both systems using T cell lines/clones from mouse and human origin indicated that Cop 1 is a TCR antagonist of the 82-100 epitope of MBP. In contrast to the broad specificity of the MHC blocking induced by Cop 1, its TCR antagonistic activity was restricted to the 82-100 determinant of MBP and could not be demonstrated for proteolipid protein peptide or even for other MBP epitopes. Yet, it was shown for all the MBP 82-100-specific T cell lines/clones tested that were derived from mice as well as from an MS patient. The ability of Cop 1 to act as altered peptide and induce TCR antagonistic effect on the MBP p82-100 immunodominant determinant response elucidates further the mechanism of Cop 1 therapeutic activity in experimental autoimmune encephalomyelitis and MS.
Assuntos
Epitopos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Proteína Básica da Mielina/imunologia , Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T/antagonistas & inibidores , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Divisão Celular/imunologia , Células Clonais/imunologia , Encefalomielite Autoimune Experimental/imunologia , Feminino , Acetato de Glatiramer , Humanos , Camundongos , Camundongos Endogâmicos , Esclerose Múltipla/imunologia , Fragmentos de Peptídeos/imunologiaRESUMO
The synthetic amino acid copolymer, copolymer 1 (Cop 1) induces T suppressor (Ts) lines/clones, which are confined to the Th2 pathway, cross react with myelin basic protein (MBP), but not with other myelin antigens on the level of Th2 cytokine secretion. Nevertheless, Cop 1 Ts cells inhibited the IL-2 response of a proteolipid protein (PLP) specific line. Furthermore, Cop 1 Ts cells ameliorated EAE induced by two unrelated encephalitogenic epitopes of PLP: p139-151 and p178-191, that produced different forms of disease. This bystander suppression demonstrated by the Cop 1 Ts cells may explain the therapeutic effect of Cop 1 in EAE and MS.
Assuntos
Encefalomielite Autoimune Experimental/imunologia , Imunossupressores/imunologia , Peptídeos/imunologia , Células Th2/imunologia , Animais , Células Clonais , Reações Cruzadas , Citocinas/imunologia , Encefalomielite Autoimune Experimental/induzido quimicamente , Epitopos/imunologia , Feminino , Acetato de Glatiramer , Camundongos , Camundongos Endogâmicos BALB C , Esclerose Múltipla/imunologia , Proteína Básica da Mielina/imunologia , Proteína Proteolipídica de Mielina/imunologia , Proteína Proteolipídica de Mielina/farmacologia , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/farmacologia , Células Th2/química , Células Th2/citologiaRESUMO
Two synthetic peptides, corresponding to the N-terminal sequence of the 45-kDa subunit of the protective 9B antigen of Schistosoma mansoni and differing in only one amino acid residue, were synthesized. These peptides were recognized by the protective monoclonal antibody 152-66-9B, as well as by sera of mice and humans infected with schistosomiasis. The peptides were coupled to a protein carrier and used for immunization. One of the peptides, 9B-peptide1, induced in mice significant protection against challenge infection, manifested in a 40 to 50% reduction in worm burden.
Assuntos
Antígenos de Helmintos/imunologia , Peptídeos/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Vacinas Sintéticas/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Anticorpos Monoclonais/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Proteínas do Sistema Complemento/imunologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/síntese química , Esquistossomose mansoni/sangue , Esquistossomose mansoni/imunologiaRESUMO
The present study describes the production of a synthetic hexapeptide (DTRPAP)-based anti-mucin (MUC-1) antibody, similar to those produced using either the intact mucin antigen or tumor extracts. This antibody was generated by immunization of rabbits with the synthetic peptide conjugated to bovine serum albumin as a carrier. Using both the ELISA and FACS analysis methods, we have shown that the antibody is reactive with human ovarian and breast cancer cells, but not with normal epithelial breast cells. This antibody is different from the previously reported anti-mucin HMFG-1, HMFG-2 and SM-3 monoclonal antibodies, since competitive experiments with the free synthetic peptide revealed only a 30% inhibition of HMFG-1 binding to the ovarian (OVCAR-3) cancer cells, as compared to 78% inhibition of the anti-synthetic peptide antibody. The peptide was non-inhibitory for HMFG-2, and induced a significant and reproducible stimulation of the SM-3 binding activity to the tumor cells.
Assuntos
Neoplasias da Mama/imunologia , Mucinas/imunologia , Neoplasias Ovarianas/imunologia , Peptídeos/imunologia , Animais , Anticorpos/metabolismo , Especificidade de Anticorpos , Citotoxicidade Imunológica , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Biossíntese Peptídica , Células Tumorais CultivadasRESUMO
The synthetic amino acid copolymer copolymer 1 (Cop 1) suppresses experimental autoimmune encephalomyelitis (EAE) and is beneficial in multiple sclerosis. To further understand Cop 1 suppressive activity, we studied the cytokine secretion profile of various Cop 1-induced T cell lines and clones. Unlike T cell lines induced by myelin basic protein (MBP), which secreted either T cell helper type 1 (Th1) or both Th1 and Th2 cytokines, the T cell lines/clones induced by Cop 1 showed a progressively polarized development toward the Th2 pathway, until they completely lost the ability to secrete Th1 cytokines. Our findings indicate that the polarization of the Cop 1-induced lines did not result from the immunization vehicle or the in vitro growing conditions, but rather from the tendency of Cop 1 to preferentially induce a Th2 response. The response of all of the Cop 1 specific lines/clones, which were originated in the (SJL/JxBALB/c)F1 hybrids, was restricted to the BALB/c parental haplotype. Even though the Cop 1-induced T cells had not been exposed to the autoantigen MBP, they crossreacted with MBP by secretion of interleukin (IL)-4, IL-6, and IL-10. Administration of these T cells in vivo resulted in suppression of EAE induced by whole mouse spinal cord homogenate, in which several autoantigens may be involved. Secretion of anti-inflammatory cytokines by Cop 1-induced suppressor cells, in response to either Cop 1 or MBP, may explain the therapeutic effect of Cop 1 in EAE and in multiple sclerosis.
Assuntos
Adjuvantes Imunológicos/farmacologia , Encefalomielite Autoimune Experimental/prevenção & controle , Imunossupressores/farmacologia , Proteína Básica da Mielina/imunologia , Peptídeos/farmacologia , Células Th2/citologia , Animais , Linhagem Celular , Reações Cruzadas , Encefalomielite Autoimune Experimental/imunologia , Acetato de Glatiramer , Interleucina-2/metabolismo , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Células Th2/imunologiaRESUMO
BACKGROUND: The risk of death in patients presenting with upper gastrointestinal (UGI) hemorrhage increases with age. Our aims were to define the background characteristics, causes, course, and outcome in patients aged > or = 80 years admitted to hospital because of acute UGI bleeding (n = 115) in relation to patients aged 60-69 years admitted for the same reason (n = 133). METHODS: A prospective, longitudinal study with a nested case-control analysis was carried out. RESULTS: In the elderly patients there was a female preponderance and a significantly higher prevalence of atherosclerotic cardiovascular disease. By contrast, use of tobacco and alcohol, diabetes mellitus, and chronic liver disease were significantly commoner in the controls. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, anticoagulants, and corticosteroids was similar in the two groups. Esophagitis was the cause of bleeding in 21.1% of the elderly, as compared with 3.3% in the controls. The relative risk of developing esophagitis in the elderly was increased and was independent of gender, smoking, alcohol consumption, use of NSAIDs, aspirin, or corticosteroids, diabetes mellitus, atherosclerotic cardiovascular disease and liver disease. (Adjusted odds ratio, 18.1; P = 0.0002). The rates of persistent or recurrent bleeding and emergency surgery to control bleeding were similar. However, the mortality in the elderly was higher (13 versus 6.1%; P = 0.09). CONCLUSIONS: Age > or = 80 years is an independent determinant of esophagitis, a major cause of UGI bleeding in the elderly.