RESUMO
The EIVIC project was launched in 2020, and the main goal was the organisation of a European intercomparison of in-vivo monitoring laboratories dealing with direct measurements of gamma-emitting radionuclides incorporated into the body of exposed workers. This project was organised jointly by members of EURADOS Working Group 7 on internal dosimetry (WG7), the Federal Office for Radiation Protection (BfS, Germany) and the Radioprotection and Nuclear Safety Institute (IRSN, France). The objective was to assess the implementation of individual-monitoring requirements in EU Member States on the basis of in-vivo measurements and to gain insight into the performance of in-vivo measurements using whole-body counters. In this context, a total of 41 in-vivo monitoring laboratories from 21 countries, together with JRC (EC) and IAEA participated. The results were submitted in terms of activity (Bq) of the radionuclides identified inside phantoms that were circulated to all participants. The measured data were compared with reference activity values to evaluate the corresponding bias according to the standards ISO 28218 and ISO 13528. In general, the results of the different exercises are good, and most facilities are in conformity with the criteria for the bias and z-scores in the ISO standards. Furthermore, information about technical and organisational characteristics of the participating laboratories was collected to test if they had a significant influence on the reported results.
Assuntos
Laboratórios , Monitoramento de Radiação , Humanos , Radiometria/métodos , Radioisótopos , França , Padrões de ReferênciaRESUMO
Respiratory syncytial virus (RSV) causes severe respiratory disease in young children. Antibodies specific for the RSV prefusion F protein have guided RSV vaccine research, and in human serum, these antibodies contribute to >90% of the neutralization response; however, detailed insight into the composition of the human B cell repertoire against RSV is still largely unknown. In order to study the B cell repertoire of three healthy donors for specificity against RSV, CD27+ memory B cells were isolated and immortalized using BCL6 and Bcl-xL. Of the circulating memory B cells, 0.35% recognized RSV-A2-infected cells, of which 59% were IgA-expressing cells and 41% were IgG-expressing cells. When we generated monoclonal B cells selected for high binding to RSV-infected cells, 44.5% of IgG-expressing B cells and 56% of IgA-expressing B cells reacted to the F protein, while, unexpectedly, 41.5% of IgG-expressing B cells and 44% of IgA expressing B cells reacted to the G protein. Analysis of the G-specific antibodies revealed that 4 different domains on the G protein were recognized. These epitopes predicted cross-reactivity between RSV strain A (RSV-A) and RSV-B and matched the potency of antibodies to neutralize RSV in HEp-2 cells and in primary epithelial cell cultures. G-specific antibodies were also able to induce antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis of RSV-A2-infected cells. However, these processes did not seem to depend on a specific epitope. In conclusion, healthy adults harbor a diverse repertoire of RSV glycoprotein-specific antibodies with a broad range of effector functions that likely play an important role in antiviral immunity.IMPORTANCE Human RSV remains the most common cause of severe lower respiratory tract disease in premature babies, young infants, the elderly, and immunocompromised patients and plays an important role in asthma exacerbations. In developing countries, RSV lower respiratory tract disease has a high mortality. Without an effective vaccine, only passive immunization with palivizumab is approved for prophylactic treatment. However, highly potent RSV-specific monoclonal antibodies could potentially serve as a therapeutic treatment and contribute to disease control and mortality reduction. In addition, these antibodies could guide further vaccine development. In this study, we isolated and characterized several novel antibodies directed at the RSV G protein. This information can add to our understanding and treatment of RSV disease.
Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Células Epiteliais/virologia , Imunoglobulina G/imunologia , Mucosa Respiratória/virologia , Vírus Sincicial Respiratório Humano/imunologia , Vírus Sinciciais Respiratórios/imunologia , Adulto , Citotoxicidade Celular Dependente de Anticorpos , Brônquios/citologia , Brônquios/imunologia , Brônquios/virologia , Células Cultivadas , Células Epiteliais/imunologia , Epitopos/imunologia , Glicoproteínas/imunologia , Voluntários Saudáveis , Humanos , Memória Imunológica , Fagocitose/imunologia , Mucosa Respiratória/citologia , Mucosa Respiratória/imunologia , Vírus Sinciciais Respiratórios/química , Traqueia/citologia , Traqueia/imunologia , Traqueia/virologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologiaRESUMO
UNLABELLED: The family Picornaviridae is a large and diverse group of positive-sense RNA viruses, including human enteroviruses (EVs) and human parechoviruses (HPeVs). The human immune response against EVs and HPeVs is thought to be mainly humoral, and an insufficient neutralizing antibody (Ab) response during infection is a risk factor and can ultimately be life threatening. The accessibility of different antigenic sites and observed cross-reactivity make HPeVs a good target for development of therapeutic human monoclonal antibodies (MAbs). In this study, we generated two different human MAbs specific for HPeV by screening culture supernatants of Ab-producing human B cell cultures for direct neutralization of HPeV1. Both MAbs showed HPeV1-specific neutralization as well as neutralization of HPeV2. One antibody, AM18, cross-neutralized HPeV4, -5, and -6 and coxsackievirus A9 (CV-A9). VP1 capsid protein-specific assays confirmed that AM18 bound VP1 of HPeV1, -2, and -4 with high affinity (11.5 pM). In contrast, the HPeV1-specific MAb AM28, which neutralized HPeV1 even more efficiently than did AM18, showed no cross-reactivity with HPeV3 to -6 or other EVs and did not bind any of the capsid proteins, suggesting that AM28 is specific for a conformation-dependent, nonlinear epitope on the virus. The discovery of MAbs that are cross-reactive between HPeVs may help development of HPeV treatment options with antibodies and vaccine design based on epitopes recognized by these antibodies. IMPORTANCE: HPeV infections are widespread among young children and adults, causing a broad range of disease. Infections can be severe and life threatening, while no antiviral treatment is available. Given that the absence of neutralizing Abs is a risk factor for severe disease in infants, treatment of picornavirus infections with MAbs would be a therapeutic option. To study antibody neutralization of HPeV in more detail, we generated two different HPeV1-specific human MAbs. Both MAbs show HPeV1-specific neutralization and cross-neutralized HPeV2. One MAb also cross-neutralized other HPeVs. Surprisingly, this MAb also neutralized CV-A9. These MAbs provide a unique tool for further research and for the diagnosis (antigen detection) and possible treatment of HPeV infections.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Parechovirus/imunologia , Infecções por Picornaviridae/imunologia , Linfócitos B/virologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Reações Cruzadas , Humanos , Países Baixos/epidemiologia , Parechovirus/classificação , Parechovirus/genética , Infecções por Picornaviridae/diagnóstico , Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/terapia , PrevalênciaRESUMO
This article provides an overview of the treatment options available for patients diagnosed with metastatic breast cancer. The article focuses on the four common organ sites affected by metastatic breast cancer, including the bone, lungs, liver and brain. The implications for nursing care are addressed, highlighting common side effects of treatment and frequent areas of concern for patients.
Assuntos
Neoplasias da Mama/terapia , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/secundário , Neoplasias da Mama/enfermagem , Neoplasias da Mama/patologia , Terapia Combinada , Feminino , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Metástase Neoplásica , RadioterapiaRESUMO
INTRODUCTION: The visceral localization of malignant fibrous hystiocytoma is rare. It provokes polymorphous, rarely specific symptoms. Although muscular or cutaneous forms of the disease are frequent in the elderly, the visceral form predominates in young immunodepressed patients. OBSERVATION: An 18 year-old, HIV-seropositive man was hospitalised for chronic abdominal pain and transit disorders. Biological examination revealed eosinophilia and imaging showed a thickening of the intestinal wall of the right iliac fossa. Surgery revealed an intrinsic tumour on the intestinal wall. The anatomopathological exploration evoked a malignant storiform histiocytoma. Despite exeresis, the tumour relapsed a few months after surgery, leading to the death of the patient. COMMENTS: This case report can be added to those of atypical localization of rare tumors in immunodepressed and young patients. The localization in the digestive tube is rare and the cases reported referred to tumors of the colon or stomach. Our case report confirms the observations of the concomitance of malignant fibrous histiocytoma and eosinophilia. The association with bacillary angiomatosic lesions is surprising and has yet to be explained.
Assuntos
Soropositividade para HIV/patologia , Histiocitoma Fibroso Benigno/patologia , Neoplasias do Íleo/patologia , Adolescente , Histiocitoma Fibroso Benigno/cirurgia , Humanos , Neoplasias do Íleo/cirurgia , Íleo/patologia , Íleo/cirurgia , Masculino , Recidiva Local de Neoplasia/patologiaRESUMO
Development of drugs targeting Bcl-2 relatives and caspases, for treating diseases including cancer and inflammatory disorders, often involves measuring interactions with recombinant target molecules, and/or monitoring cancer cell killing in vitro. Here, we present yeast-based methods for evaluating drug-mediated inhibition of Bcl-2 relatives or caspases. Active Bax and caspases kill Saccharomyces cerevisiae, and pro-survival Bcl-2 proteins can inhibit Bax-induced yeast death. By measuring the growth or adenosine triphosphate content of transformants co-expressing Bax with pro-survival Bcl-2 relatives, we found that the Bcl-2 antagonist drugs ABT-737 or ABT-263 abolished Bcl-2 or Bcl-xL function and reduced Bcl-w activity, but failed to inhibit Mcl-1, A1 or the poxvirus orthologs DPV022 and SPPV14. Using this technique, we also demonstrated that adenoviral E1B19K was resistant to these agents. The caspase inhibitor Q-VD-OPh suppressed yeast death induced by caspases 1 and 3. Yeast engineered to express human apoptotic regulators enable simple, automatable assessment of the activity and specificity of candidate drugs targeting Bcl-2 relatives or caspases.
Assuntos
Caspases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Inibidores de Caspase/farmacologia , Caspases/química , Nitrofenóis/farmacologia , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Quinolinas/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Sulfonamidas/farmacologia , Proteína X Associada a bcl-2/metabolismo , Proteína bcl-X/metabolismoRESUMO
Although there have been major improvements in the management of breast cancer, with a rapidly falling death rate despite an increasing incidence of the disease, metastatic breast cancer remains common and the cause of death in nearly 12 000 women annually in the UK. Numerous treatment options are available that either target the tumour or reduce the complications of the disease. Clinical decision making depends on knowledge of the extent and biology of the disease and available drug options, an understanding of the functional status, and also the wishes and expectations of the individual patient. In addition, the organisation of services and support of the patient are essential components of high-quality care. The National Institute for Health and Clinical Excellence (NICE) has produced guidelines for the treatment of advanced breast cancer, which in some areas have perhaps failed to appreciate the complexity of patient management. This guidance document aims to provide succinct practical advice on the treatment of metastatic breast cancer, highlight some limitations of the NICE guidelines, and provide suggestions for management where available data are limited.
Assuntos
Neoplasias Ósseas/terapia , Neoplasias Encefálicas/terapia , Neoplasias da Mama/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Inibidores da Aromatase/uso terapêutico , Neoplasias Ósseas/secundário , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Terapia Combinada , Tomada de Decisões , Feminino , Gosserrelina/uso terapêutico , Humanos , Ovariectomia , Equipe de Assistência ao Paciente , Pós-Menopausa , Pré-Menopausa , Radioterapia , Tamoxifeno/uso terapêutico , Reino UnidoRESUMO
Information concerning gender identity, sexual orientation, cross-dressing behavior, fetishism, and bondage was obtained from a questionnaire which was posted to members of two transvestite clubs, one in the United States and one in Australia. This study reports the responses of 136 American and 86 Australian self-designated transvestites who reported a period of fetishism to women's clothes at some stage of development. Characteristics of transvestism of subjects in both countries were remarkably similar; all were male, almost half the subjects first cross-dressed in prepuberty, and in the large majority cross-dressing was well established by late adolescence; intense fetishism was usually experienced during adolescence but waned in later years; in almost a quarter of subjects fetishism ceased, although the desire to cross-dress continued; in many subjects transvestism was associated with fantasies of bondage, usually of the subjects bound while cross-dressed; sexual orientation was predominantly or exclusively heterosexual in more than three-quarters of the subject. Subjects were categorized into two groups. One group, termed nuclear transvestites, were satisfied with cross-dressing. The second group, termed marginal transvestites, desired feminization by hormone ingestion or by surgical intervention. Marginal compared to nuclear transvesites reported significantly stronger feminine gender identity and tended to report a stronger interest in the homosexual direction. The differences appeared to be present from childhood. No significant differences were found between the nuclear and marginal transvestites with regard to characteristics of fetishism, bondage, and cross-dressing except that in the American group marginal transvestites currently cross-dressed more frequently than did nuclear transvestites.
Assuntos
Travestilidade/psicologia , Adulto , Idoso , Austrália , Comparação Transcultural , Fetichismo Psiquiátrico/psicologia , Identidade de Gênero , Humanos , Masculino , Masoquismo , Pessoa de Meia-Idade , Comportamento Sexual , Estados UnidosRESUMO
The cellular constituents of the blood-brain barrier (BBB) must make finely tuned, regulatory responses to maintain microvascular homeostasis. The mechanisms by which this task is accomplished are largely unknown. However, it is thought they involve a series of cross-talk mechanisms among endothelial cells (EC), pericytes (PC), and astrocytes. During inflammation, the BBB is exposed to a number of biological response modifiers including cytokines released by infiltrating leukocytes. The response to inflammatory cytokines may alter the normal regulatory function of EC and PC. These changes may account for some of the pathological findings in central nervous system (CNS) inflammatory disease. Previous studies have shown that PC and EC may have immune potential. We have investigated the response of the PC to a variety of inflammatory cytokines. Primary rat PC constitutively express low levels of intercellular adhesion molecule-1 (ICAM-1) and major histocompatibility complex (MHC) class I molecule, which can be upregulated in response to the cytokine interferon-gamma (IFNgamma). IFNgamma also induced the expression of MHC class II molecule. After induction of MHC class II molecule, CNS PC acquired the capacity to present antigen to primed syngeneic rat T-lymphocytes. Antigen presentation by PC was comparable to that seen with classic antigen-presenting cells. A small number of primary PC constitutively express low levels of vascular cell adhesion molecule-1 (VCAM-1), which was increased on exposure to tumor necrosis factor-alpha (TNFalpha). Results suggest that CNS PC respond to inflammatory cytokines, are involved in T-lymphocyte activation, and express cell surface adhesion molecules (VCAM-1, ICAM-1) that may provide costimulatory activity. It is likely that CNS PC are important in neuroimmune networks at the BBB.
Assuntos
Antígenos/imunologia , Sistema Nervoso Central/irrigação sanguínea , Ativação Linfocitária , Pericitos/fisiologia , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Antígenos de Histocompatibilidade Classe I/biossíntese , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/biossíntese , Antígenos de Histocompatibilidade Classe II/imunologia , Interferon gama/farmacologia , Proteína Básica da Mielina/imunologia , Pericitos/citologia , Pericitos/efeitos dos fármacos , Pericitos/imunologia , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos Lew , Baço/imunologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system in which peripheral blood monocytes play an important role. We have previously reported that patients with chronic progressive MS (CPMS) have significantly increased numbers of circulating monocytes which express the urokinase plasminogen activator receptor (uPAR). In the present study, we examined the expression of uPAR on monocytes in patients with relapsing-remitting multiple sclerosis (RRMS) not currently participating in a clinical trial and in patients with RRMS who were enrolled in a double-blind multicenter clinical trial designed to examine the effect of glatiramer acetate (copolymer 1; Copaxone) on relapsing disease. Patients with CPMS have sustained high levels of circulating uPAR-positive (uPAR(+)) monocytes. In comparison, patients with RRMS displayed variable levels of circulating uPAR(+) monocytes. Mean values for uPAR in patients with RRMS were above those seen for controls but were not as high as those observed for patients with secondary progressive MS. Patients with RRMS in the clinical trial also had variable levels of monocyte uPAR. However, patients in the treatment group displayed lower levels following 2 years of treatment. In both placebo-treated and glatiramer acetate-treated patients, the percentage of circulating uPAR(+) monocytes, as well as the density of uPAR expressed per cell (mean linear fluorescence intensity), increased just prior to the onset of a clinically documented exacerbation. Values fell dramatically with the development of clinical symptoms. uPAR levels in all groups correlated with both clinical activity and severity. Results indicate that monocyte activation is impatient in MS and that glatiramer acetate may have a significant effect on monocyte activation in patients with RRMS.
Assuntos
Imunossupressores/uso terapêutico , Monócitos/metabolismo , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/imunologia , Peptídeos/uso terapêutico , Receptores de Superfície Celular/biossíntese , Anticorpos Monoclonais , Avaliação da Deficiência , Método Duplo-Cego , Feminino , Citometria de Fluxo , Acetato de Glatiramer , Humanos , Estudos Longitudinais , Masculino , Monócitos/química , Monócitos/imunologia , Esclerose Múltipla Crônica Progressiva/tratamento farmacológico , Esclerose Múltipla Crônica Progressiva/imunologia , Receptores de Superfície Celular/análise , Receptores de Superfície Celular/imunologia , Receptores de Ativador de Plasminogênio Tipo UroquinaseRESUMO
Any perturbation of the blood brain barrier, whether from changes in cell physiology or from direct injury, may result in microvascular dysfunction and disease. We examined, at the ultrastructural level, microvascular pericyte responses in a well-defined model of traumatic brain injury in the rat. In areas close to the site of impact cortical pericytes underwent a number of changes within the first hour. Approximately 40% of pericytes migrated from their microvascular location. Migration occurred concomitant with a thinning of the abluminal surface of the basal lamina and an accumulation of the receptor for the urokinase plasminogen activator on the leading surface of the migrating cell. Migrated pericytes appeared viable and remained in a perivascular location in the adjacent neuropil. Nonmigrating pericytes in the same section displayed cytoplasmic alterations and nuclear chromatin changes consistent with a rapid degenerative process.
Assuntos
Barreira Hematoencefálica/fisiologia , Lesões Encefálicas/patologia , Encéfalo/irrigação sanguínea , Pericitos/fisiologia , Animais , Capilares/patologia , Movimento Celular , Masculino , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Pericitos/ultraestrutura , Ratos , Ratos Sprague-Dawley , Receptores de Superfície Celular/fisiologia , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Regulação para Cima , Ferimentos não PenetrantesRESUMO
YAC lymphoma cells were treated with the mutagen N-methyl-N'-nitro-N-nitrosoguanidine and then cloned and subcloned. Of 51 clones, 3 were selected for further study. Ten-fold more natural killer (NK) effector cells were required to lyse YAC clone 6 and subclone 6-28 cells compared with clone 19 cells or the YAC parent cell line. The maximum plateau level of cytolysis of the NK-resistant (NKR) variants (20%) never approached that of the NK-sensitive (NKS) variants or YAC parental cells (60%) even after prolonged incubation (20 hr). NKR variants appeared with equal frequency (0.10) on cloning YAC cells that had not been treated with mutagen but these variants were highly unstable with respect to NK sensitivity and were not studied further. Cytolysis of both NKR and NKS lines was mediated by nylon-nonadherent asialo-GM1+ effector cells, and effectors from poly(I) . poly(C)-boosted mice preferentially lysed the NKS lines. The NKR alteration did not appear to change the NK target structure (NK-TS): (i) unlabeled NKR cells competed equally with NKS cells in reciprocal unlabeled-target competition assays; (ii) the frequency of target--effector conjugates was identical with NKR or NKS lines; and (iii) normal rabbit serum, which contains antibodies thought to react with the NK-TS, reacted equally against both NKR and NKS targets. The NKR alteration was selective for NK cells and did not result in a resistance to lysis in general; NKR and NKS variants were equally susceptible to (i) cytolysis mediated by alloimmune or lectin-dependent effector T cells and (ii) antibody- and complement-mediated lysis. These results are compatible with the hypothesis that the NKR variants have an altered acceptor site on the target cell membrane that normally binds the "lytic moiety" delivered by the effector cell.
Assuntos
Células Matadoras Naturais/imunologia , Leucemia Experimental/imunologia , Linfoma/imunologia , Animais , Linhagem Celular , Células Clonais/imunologia , Variação Genética , Metilnitronitrosoguanidina/farmacologia , Camundongos , MutaçãoRESUMO
The role of humoral immunity in controlling human immunodeficiency virus type 1 (HIV-1) is still controversial. The resistance of primary HIV-1 variants to neutralization by antibodies, sera from HIV-1-infected patients, and soluble CD4 protein has been suggested to be a prerequisite for the virus to establish persistence in vivo. To further test this hypothesis, we studied the neutralization sensitivity of two IIIB/LAV variants that were isolated from a laboratory worker who accidentally was infected with the T-cell-line-adapted neutralization-sensitive IIIB isolate. Compared to the original virus in the inoculum, the reisolated viruses showed an increased resistance to neutralization over time. The ratio of nonsynonymous to synonymous nucleotide substitutions in the envelope gene pointed to strong positive selection. The emergence of neutralization-resistant HIV preceded disease development in this laboratory worker. Our results imply that the neutralization resistance of primary HIV may indeed be considered an escape mechanism from humoral immune control.
Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Pessoal de Laboratório Médico , Sequência de Aminoácidos , Linhagem Celular , Progressão da Doença , Produtos do Gene env/química , Infecções por HIV/imunologia , Infecções por HIV/fisiopatologia , HIV-1/classificação , HIV-1/genética , Humanos , Macrófagos/virologia , Dados de Sequência Molecular , Testes de Neutralização , Exposição Ocupacional , Fenótipo , Filogenia , Receptores CCR5/metabolismo , Receptores CXCR4/metabolismo , Análise de Sequência de DNARESUMO
Prolonged exposure to low oxygen may induce adaptive changes which can be either beneficial or deleterious to cell survival. We examined the effect of prolonged moderate hypobaric hypoxia on CNS endothelial cell (EC) function. Exposure to hypoxia resulted in expression of EC activation markers, the cell surface adhesion proteins intracellular adhesion molecule-1 and E-selectin. Induction of the major histocompatibility complex (MHC) class II molecule as well as increased constitutive expression of the transferrin receptor and the glucose transporter-1 protein was also detected within 24 h of exposure to hypobaric hypoxia. Constitutive expression of the MHC class I molecule increased by 48 h. Expression of most EC activation markers increased with time from 0 to 2 weeks. By 3 weeks of exposure to hypobaric hypoxia, ECs returned to their quiescent state with the exception of sustained expression of E-selectin and elevated glut-1. Little to no significant increase in expression of vascular cell adhesion molecule-1 was seen at any time period.
Assuntos
Endotélio Vascular/fisiopatologia , Hipóxia/fisiopatologia , Adaptação Fisiológica , Animais , Córtex Cerebral/irrigação sanguínea , Selectina E/metabolismo , Endotélio Vascular/patologia , Transportador de Glucose Tipo 1 , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Hipóxia/patologia , Molécula 1 de Adesão Intercelular/metabolismo , Masculino , Microcirculação/patologia , Microcirculação/fisiopatologia , Proteínas de Transporte de Monossacarídeos/metabolismo , Pressão , Ratos , Ratos Wistar , Receptores da Transferrina/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismoRESUMO
The mechanism of tumour cell destruction by natural killer (NK) cells or other lymphocytes is not understood. NK cells appear to represent a primitive anti-tumour surveillance system more analogous to macrophages than lymphocytes. Free oxygen radicals (O-2, OH) and H2O2 are thought to be involved in cell destruction by macrophages and therefore we looked for similar cytocidal intermediates of oxygen in NK cells. These highly reactive molecular species can easily be detected in the presence of luminol by the emission of light. We show here that highly enriched human NK cells respond to NK-sensitive but not NK-insensitive tumour cells with a rapid burst of oxygen metabolites as detected both by chemiluminescence and cytochrome c reduction. Agents which can prevent chemiluminescence and cytochrome c reduction, such as superoxide dismutase (SOD), reduced NK-mediated cytolysis and agents which increased chemiluminescence, such as interferon, also increased NK-mediated cytolysis. These results suggest that the production of oxygen species may be the earliest event to occur in the NK cell following tumour cell contact, and these products are involved in NK-mediated cytolysis.
Assuntos
Células Matadoras Naturais/metabolismo , Oxigênio/metabolismo , Animais , Citotoxicidade Imunológica , Humanos , Técnicas In Vitro , Interferons/farmacologia , Linfócitos/metabolismo , Macrófagos/metabolismo , Camundongos , NADH Desidrogenase/metabolismo , Neoplasias Experimentais/imunologia , Superóxido Dismutase/farmacologia , Superóxidos/metabolismoRESUMO
Development of disease is extremely rare in chimpanzees when inoculated with either T-cell-line-adapted neutralization-sensitive or primary human immunodeficiency virus type 1 (HIV-1), at first excluding a role for HIV-1 neutralization sensitivity in the clinical course of infection. Interestingly, we observed that short-term in vivo and in vitro passage of primary HIV-1 isolates through chimpanzee peripheral blood mononuclear cells (PBMC) resulted in a neutralization-sensitive phenotype. Furthermore, an HIV-1 variant reisolated from a chimpanzee 10 years after experimental infection was still sensitive to neutralization by soluble CD4, the CD4 binding site recognizing antibody IgG1b12 and autologous chimpanzee serum samples, but had become relatively resistant to neutralization by polyclonal human sera and neutralizing monoclonal antibodies. The initial adaptation of HIV-1 to replicate in chimpanzee PBMC seemed to coincide with a selection for viruses with low replicative kinetics. Neither coreceptor usage nor the expression level of CD4, CCR5, or CXCR4 on chimpanzee PBMC compared to human cells could explain the phenotypic changes observed in these chimpanzee-passaged viruses. Our data suggest that the increased neutralization sensitivity of HIV-1 after replication in chimpanzee cells may in part contribute to the long-term asymptomatic HIV-1 infection in experimentally infected chimpanzees.
Assuntos
Infecções por HIV/virologia , HIV-1/patogenicidade , Leucócitos Mononucleares/virologia , Replicação Viral/fisiologia , Animais , Anticorpos , Antígenos CD4/imunologia , Antígenos CD4/metabolismo , Células Cultivadas , HIV-1/imunologia , HIV-1/fisiologia , Humanos , Leucócitos Mononucleares/metabolismo , Testes de Neutralização , Pan troglodytes , Fenótipo , Receptores CCR5/imunologia , Receptores CCR5/metabolismo , Receptores CXCR4/imunologia , Receptores CXCR4/metabolismo , Fatores de TempoRESUMO
The rosetting of sheep erythrocytes (SRBC) coated with non-haemagglutinating monoclonal antibodies rather than conventional haemagglutinating antisera revealed readily detectable FcR on most splenic natural killer (NK) cells since 76% of splenic lymphocytes forming conjugates with YAC also rosetted with SRBC coated with high concentrations of monoclonal anti-SRBC antibody of the IgG2b subclass and since Ficoll depletion or enrichment of splenic lymphocytes rosetting with IgG2b-coated SRBC resulted in a corresponding 4-fold decrease or increase in conjugate-forming cells and a 10-fold decrease or increase in NK cytolytic activity. NK cells bound much less readily to monoclonal IgG2a and not at all to monoclonal IgG1 or IgM, but the degree of binding was directly proportional to the amount of antibody on the erythrocytes and was not isotope-restricted. In addition, immunofluorescent studies revealed that YAC-1-conjugated lymphocytes were Lyt-1-, Lyt-2-, partially Thy-1+ (60%), asialo(GM1+ (80%). Qa-4+ (77%), Qa-5+ (79%), and Ly-5+ (94%). In comparison, a proportion (39%) of alloimmune peritoneal exudate cells which conjugated with P815-2 also stained by immunofluorescence with anti-asialo GM1 antisera. Most (greater than 90%) P815-conjugated cells were Thy-1+, Lyt-2%, and a subpopulation of Lyt-1+2+ conjugates was observed (25%). Qa-5 and Ly-5 were also expressed on most (two-thirds) cytolytic T lymphocytes (CTL) conjugates, whereas Qa-4 and FcR for IgG2b were not detected. The best phenotype distinctions between NK cells and CTL were therefore based on the presence or absence of Lyt-2, Qa-4, and FcR for IgG2b on most effector cells. Anti-asialo-GM1 or monoclonal anti-Qa-4 and complement treatment greatly diminished both the frequency of NK conjugates and the percentage of conjugates with detectable IgG2b FcR or asialo-GM1. These results confirm that NK cells co-express asialo-GM1 and Fc receptors, at the single-cell level, and provide a simple method for greatly enriching NK populations at least 10-fold.