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1.
Mol Psychiatry ; 28(1): 108-117, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36284159

RESUMO

Early life development and its divergence is influenced by multiple genetic, neurological, and environmental factors. Atypical neurodevelopment, such as that observed in autism spectrum disorder, likely begins in early gestation during a period of entwined growth between the brain and epithelial barriers of the skin, gastrointestinal tract, and airway. This review coalesces epidemiological and neuroinflammatory evidence linking cutaneous atopic disease with both reduced skin barrier integrity and determinants of neurodivergence. We consider the shared developmental origin of epidermal and neural tissue with related genetic and environmental risk factors to evaluate potential pre- and postnatal modifiers of the skin-brain connection. Initial postnatal skin barrier integrity may provide a useful marker for both cortical integrity and meaningful subgroups of children showing early neurodevelopmental delays. It may also modify known risk factors to neurodevelopment, such as pathogen caused immune system activation. These novel insights of a skin-brain-neurodevelopment connection may advance detection and intervention opportunities.


Assuntos
Transtorno do Espectro Autista , Transtornos do Neurodesenvolvimento , Criança , Humanos , Transtorno do Espectro Autista/genética , Encéfalo , Inflamação , Fatores de Risco
2.
J Dev Orig Health Dis ; 7(5): 433-439, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27118250

RESUMO

The evidence underpinning the developmental origins of health and disease (DOHaD) is overwhelming. As the emphasis shifts more towards interventions and the translational strategies for disease prevention, it is important to capitalize on collaboration and knowledge sharing to maximize opportunities for discovery and replication. DOHaD meetings are facilitating this interaction. However, strategies to perpetuate focussed discussions and collaborations around and between conferences are more likely to facilitate the development of DOHaD research. For this reason, the DOHaD Society of Australia and New Zealand (DOHaD ANZ) has initiated themed Working Groups, which convened at the 2014-2015 conferences. This report introduces the DOHaD ANZ Working Groups and summarizes their plans and activities. One of the first Working Groups to form was the ActEarly birth cohort group, which is moving towards more translational goals. Reflecting growing emphasis on the impact of early life biodiversity - even before birth - we also have a Working Group titled Infection, inflammation and the microbiome. We have several Working Groups exploring other major non-cancerous disease outcomes over the lifespan, including Brain, behaviour and development and Obesity, cardiovascular and metabolic health. The Epigenetics and Animal Models Working Groups cut across all these areas and seeks to ensure interaction between researchers. Finally, we have a group focussed on 'Translation, policy and communication' which focusses on how we can best take the evidence we produce into the community to effect change. By coordinating and perpetuating DOHaD discussions in this way we aim to enhance DOHaD research in our region.

3.
BJOG ; 123(2): 225-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26840907

RESUMO

OBJECTIVE: To assess maternal abdominal subcutaneous fat thickness (SFT) measured by ultrasound as an independent predictor of adverse pregnancy outcomes. DESIGN: A prospective longitudinal cohort study performed on pregnancies delivered between 2012 and 2014. SETTING: Sydney, Australia. POPULATION: About 1510 pregnant women attending routine obstetric ultrasounds. METHODS: Maternal SFT was measured on routine ultrasounds at 11-14 weeks' gestation (SFT1) and 18-22 weeks' gestation (SFT2). SFT measurements were assessed for estimating risks for obesity-related pregnancy outcomes using logistic regression modelling adjusted for maternal age, parity, smoking status and body mass index (BMI). MAIN OUTCOME MEASURES: Hypertensive disease, gestational diabetes, caesarean section, low birthweight, preterm delivery, neonatal respiratory distress, Apgar scores, and admission to a neonatal intensive care unit. RESULTS: SFT1 and SFT2 were measured on 1461 and 1363 women, respectively. Mean thickness (range) were 21.2 mm (6.9-73.9) for SFT1 and 20.3 mm (7.5-68.0) for SFT2. Complete outcome data were available for 1385 pregnancies. In all, 54% of the women were overweight/obese. The SFT measures decreased from early to mid-pregnancy in overweight/obese women. There was moderate correlation between BMI and SFT1 (R(2) = 0.56) and BMI and SFT2 (R(2) = 0.55). In a multivariate model, SFT1 and SFT2 were better predictors for adverse pregnancy outcomes than BMI. CONCLUSION: Maternal SFT is a significant independent predictor of adverse pregnancy outcomes. Incorporation of SFT into future models for adverse pregnancy outcome may prove valuable.


Assuntos
Obesidade/complicações , Complicações na Gravidez/etiologia , Gordura Subcutânea Abdominal/patologia , Adulto , Índice de Apgar , Austrália/epidemiologia , Índice de Massa Corporal , Cesárea , Feminino , Hospitais Privados , Humanos , Recém-Nascido , Estudos Longitudinais , Obesidade/fisiopatologia , Valor Preditivo dos Testes , Gravidez , Complicações na Gravidez/fisiopatologia , Resultado da Gravidez , Estudos Prospectivos , Fatores de Risco , Centros de Atenção Terciária
4.
Ultrasound Obstet Gynecol ; 37(4): 410-5, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21308839

RESUMO

OBJECTIVE: To determine whether the thymus is smaller in fetuses of pre-eclamptic mothers than in those of normal controls. METHODS: This was a cross-sectional, prospective, comparative study of sonographically determined fetal thymus measurements in 39 pregnancies with pre-eclampsia and 70 healthy pregnancies. RESULTS: Both the diameter and the perimeter of the fetal thymus were smaller in pregnancies with pre-eclampsia than in healthy controls. The means of the thymus diameters were 28.6 ± 5.9 and 32.9 ± 4.5 mm and of thymus perimeters 80.9 ± 16.5 and 93.1 ± 16.6 mm for pre-eclamptic and healthy pregnancies, respectively (P < 0.001). General linear models showed that smaller fetal thymuses in pre-eclampsia were independent of gestational age, estimated fetal weight, small for gestational age status and antenatal steroid use. CONCLUSIONS: Pre-eclampsia is associated with smaller fetal thymuses.


Assuntos
Pré-Eclâmpsia/diagnóstico por imagem , Timo/diagnóstico por imagem , Adolescente , Adulto , Estudos Transversais , Feminino , Feto , Idade Gestacional , Humanos , Tamanho do Órgão , Gravidez , Estudos Prospectivos , Fatores de Risco , Timo/embriologia , Timo/patologia , Ultrassonografia Pré-Natal/métodos , Adulto Jovem
5.
Arch Dis Child Fetal Neonatal Ed ; 95(4): F258-62, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20388645

RESUMO

BACKGROUND AND AIMS: Intrauterine growth restriction (IUGR) can lead to significant intellectual and behavioural problems in later life. IUGR represents a frequent feature of pregnancies of opioid-dependent mothers (ODMs), the causes of which are largely unknown. The objective of this study was to determine the independent risk factors for IUGR in ODMs. DESIGN AND SUBJECTS: We performed a retrospective study analysing maternal and neonatal parameters from pregnancies of ODM maintained on methadone (n=215). These were compared to smoking non-ODM and non-smoking non-ODM control groups matched for maternal age, gestational age at delivery, infant birth date and sex. Logistic regression analysis was performed on all parameters with the outcome of IUGR. RESULTS: Fifty-seven infants (27%) of ODMs showed IUGR. Compared to non-smoking non-ODMs, the risk of IUGR in non-smoking ODMs was almost four times higher (relative risk 3.48, 95% CI 1.70 to 7.14). Growth restriction was independent of the last maternal methadone dose and the cumulative methadone dose during pregnancy. In addition, whereas nicotine and female sex impacted on IUGR in non-ODMs (nicotine: OR 3.45, 95% CI 1.82 to 6.67; sex: OR 2.37, 95% CI 1.25 to 4.50), these parameters had no influence on IUGR in ODMs. Maternal body mass index (BMI) was identified as the only independent risk factor for IUGR in infants of ODMs (OR 1.15, 95% CI 1.03 to 1.28). CONCLUSIONS: IUGR in pregnancies of ODM is related to maternal BMI rather than to opiate dosing, nicotine use or infant sex. BMI may itself be an indirect marker of several other genetic, nutritional and/or social determinants of IUGR.


Assuntos
Retardo do Crescimento Fetal/etiologia , Transtornos Relacionados ao Uso de Opioides/reabilitação , Complicações na Gravidez/reabilitação , Adulto , Índice de Massa Corporal , Relação Dose-Resposta a Droga , Métodos Epidemiológicos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Masculino , Troca Materno-Fetal , Metadona/uso terapêutico , Entorpecentes/uso terapêutico , Gravidez , Fatores Sexuais , Adulto Jovem
7.
Klin Padiatr ; 214(5): 299-302, 2002.
Artigo em Alemão | MEDLINE | ID: mdl-12235547

RESUMO

We report an 18-months-old boy with congenital spleen hypoplasia and cardiovascular defects. Besides, several minor clinical manifestations such as facial anomalies, hypospadia glans penis, agenesis of the corpus callosum and iris anomalies were observed. A partial or complete lateralisation defect could be excluded. The patient's phenotype comprises a previously undescribed combination of major and minor clinical features of the Ivemark syndrome. The case indicates that a common genetic defect might be the cause of this syndrome, which shows a variable expression.


Assuntos
Anormalidades Múltiplas/diagnóstico , Baço/anormalidades , Seguimentos , Cardiopatias Congênitas/diagnóstico , Humanos , Lactente , Recém-Nascido , Masculino , Fenótipo , Infecções Pneumocócicas/diagnóstico , Choque Séptico/diagnóstico , Síndrome
8.
Ann Hematol ; 81(6): 332-5, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12107564

RESUMO

A boy of Caucasian origin with a new subtype of autoimmune lymphoproliferative syndrome (ALPS) is described. The clinical picture was dominated by chronic noninfectious lymphadenopathy, splenomegaly, and recurrent bacterial infections. At the age of 6 the patient died of pneumococcal meningitis. Laboratory investigation disclosed impaired apoptosis in both B- and T-lymphocyte subsets and expanded populations of CD3+CD4-CD8- T lymphocytes. Furthermore, marked dysregulation of humoral immune responses with transient expansion of monoclonal B cells, corresponding monoclonal gammopathy, and the presence of autoantibodies was found. Functional and molecular analysis revealed that Fas protein expression was normal, a mutation in the Fas gene was not found. Moreover, transcription of the downstream effector caspase-10 was unremarkable. This patient is unique compared to previously described patients as severe humoral immunodeficiency and monoclonal gammopathy are usually not described in patients with ALPS. This case points out the important role of apoptosis in regulating the degree of humoral immune responses at a clonal level in humans and gives further evidence for the phenotypic diversity of ALPS.


Assuntos
Doenças Autoimunes/complicações , Transtornos Linfoproliferativos/imunologia , Paraproteinemias/imunologia , Imunodeficiência Combinada Severa/complicações , Pré-Escolar , Humanos , Lactente , Linfócitos/metabolismo , Transtornos Linfoproliferativos/complicações , Masculino , Paraproteinemias/complicações , Fenótipo , Receptor fas/genética
9.
Vaccine ; 20(3-4): 498-504, 2001 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-11672915

RESUMO

In search for a parameter that is predictive of long-term immunity, we analysed the influence of booster immunisations on frequencies of circulating memory B-lymphocytes. Specific IgG-secreting B-cells were determined by ELISPOTassay in 13 healthy adults, using diphtheria and tetanus toxoid as model antigens. Our results show that memory B-cells accumulate with every immunisation dose and remain elevated over several years. In addition, secondary B-cell responses were studied during the first 90 days after diphtheria re-immunisation. A significant indirect correlation was found between the number of previous boosters and the magnitude of specific B-cell expansion. In contrast, effects of booster immunisations did not correlate likewise with antigen-specific serology. Hence, this study illustrates that frequencies of antigen-specific B-lymphocytes can be used as an indirect measure for immunological memory. This parameter could be helpful to find scientifically based immunisation strategies for currently available and novel vaccines.


Assuntos
Antígenos/imunologia , Linfócitos B/imunologia , Imunização Secundária , Memória Imunológica , Adulto , Feminino , Humanos , Contagem de Linfócitos , Masculino
10.
Ann Hematol ; 80(11): 674-6, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11757727

RESUMO

We report the case of an 18-month-old girl who died of overwhelming pneumococcal sepsis. Autopsy revealed a small spleen with unusual architecture. There was a marked rarefaction of the white pulp with only very few but florid germinal centers. Immunohistochemical staining showed a low number of T and B lymphocytes in the spleen, whereas normal numbers and distribution of lymphocytes were found in all other primary and secondary lymphatic organs. Whereas levels of IgM were normal, IgA and IgG levels were significantly lower than in age-matched controls. Consistent with serological data, B cells mainly expressed IgM and IgD, whereas IgG expression was lower than expected. Additionally, intestinal immunoglobulin distribution in B-cell areas of lymphofollicular hyperplasia showed normal expression of IgM, but almost no expression of IgA. A review of the literature failed to disclose a similar case of dysgammaglobulinemia associated with isolated structural spleen anomalies. We propose that the patient suffered from a defect of the B-cell differentiation pathway.


Assuntos
Disgamaglobulinemia/complicações , Infecções Oportunistas/mortalidade , Infecções Pneumocócicas/mortalidade , Sepse/mortalidade , Baço/anormalidades , Disgamaglobulinemia/imunologia , Feminino , Humanos , Imunoglobulinas/sangue , Lactente , Infecções Oportunistas/complicações , Infecções Oportunistas/patologia , Infecções Pneumocócicas/complicações , Infecções Pneumocócicas/patologia , Sepse/complicações , Sepse/patologia
11.
J Gen Virol ; 81(Pt 5): 1313-9, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10769074

RESUMO

Measles virus (MV), a single-stranded negative-sense RNA virus, is an important pathogen causing almost 1 million deaths annually. Acute MV infection induces immunity against disease throughout life. The immunological factors which are responsible for protection against measles are still poorly understood. However, T-cell-mediated immune responses seem to play a central role. The emergence of new single-cell methods for quantification of antigen-specific T-cells directly ex vivo has prompted us to measure frequencies of MV-specific memory T-cells. As an indicator for T-cell activation IFN-gamma production was measured. PBMC were analysed by intracellular staining and ELISPOT assay after stimulation with MV-infected autologous B-lymphoblastoid cell lines or dendritic cells. T-cell responses were exclusively seen with PBMC from MV-seropositive healthy adults with a history of natural measles in childhood. The median frequency of MV-specific T-cells was 0.35% for CD3(+)CD4(+) and 0.24% for the CD3(+)CD8(+) T-cell subset. These frequencies are comparable with T-cell numbers reported by other investigators for persistent virus infections such as Epstein-Barr virus, cytomegalovirus or human immunodeficiency virus. Hence, this study illustrates that MV-specific CD4(+) and CD8(+) T-cells are readily detectable long after the acute infection, and thus are probably contributing to long-term immunity. Furthermore, this new approach allows efficient analysis of T-cell responses from small samples of blood and could therefore be a useful tool to further elucidate the role of cell-mediated immunity in measles as well as in other viral infections.


Assuntos
Memória Imunológica , Vírus do Sarampo/imunologia , Sarampo/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/virologia , Linhagem Celular , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Complexo Principal de Histocompatibilidade
12.
Neuroradiology ; 42(11): 845-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11151694

RESUMO

We report a 14-year-old girl with an unusual pattern of leukoencephalopathy after intentional intoxication with morphine sulphate tablets. Toxicological analysis showed exceedingly high levels of morphine and its metabolites. MRI disclosed a leukoencephalopathy with high signal from the centrum semiovale, corpus callosum and cerebellar white matter on T2-weighted images. These findings could be only partially explained by a hypoxic-ischaemic event; neurotoxic effects must be considered in this atypical leukoencephalopathy.


Assuntos
Morfina/intoxicação , Entorpecentes/intoxicação , Síndromes Neurotóxicas/diagnóstico , Adolescente , Encéfalo/patologia , Isquemia Encefálica/complicações , Isquemia Encefálica/etiologia , Feminino , Humanos , Leucócitos , Imageamento por Ressonância Magnética , Necrose , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/patologia
13.
Am J Surg Pathol ; 23(7): 829-37, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10403307

RESUMO

The FAS (CD95/APO-1) receptor and its ligand play an important role in the initiation of apoptosis under many physiologic conditions. Loss of function mutations of the FAS gene have been described in lpr mice and in humans with autoimmune phenomena, recurrent lymphadenopathies, and hepatosplenomegaly. This syndrome is now called autoimmune lymphoproliferative syndrome type I (ALPS I). Recently, patients with similar clinical symptoms due to a functional FAS deficiency without FAS gene mutations have been distinguished. This disease has been termed autoimmune lymphoproliferative syndrome type II (ALPS II) or autoimmune lymphoproliferative disease (ALD). This report is the first description of the lymph node pathology and immunohistochemistry in a patient with ALPS II. After recurrent bacterial infections, a 4-year-old child developed cervical giant lymphadenopathy suggesting lymphoma. Lymph node histology resembled the findings in Epstein Barr virus-associated posttransplant atypical lymphoproliferations. Confluent sheets of immunoblasts, however, showed a monoclonal expression of IgG/lambda and a monoclonal rearrangement of the JH chain. The same clone was also present in the peripheral blood. Although high-grade lymphoma could not be excluded, the patient's parents insisted on the patient's leaving the hospital with only antibiotic treatment. Surprisingly, the giant lymphadenopathy completely resolved within 7 weeks, and the clone was no longer detectable in the peripheral blood. Twelve months later the patient was still free from lymphoma and was doing well. Retrospectively, transient monoclonal B-cell populations could be identified in an archival frozen blood sample taken when the patient was 3 years old. Increased FAS-independent spontaneous apoptosis was a feature of the patient's lymphocytes and could be the molecular basis for self-elimination of B-cell clones. We conclude that the diagnosis of a FAS-FAS-L deficiency should be considered in children with an otherwise unexplained atypical lymphoproliferation and that a diagnosis of lymphoma in patients with functional FAS deficiency should be made with considerable reservation.


Assuntos
Doenças Autoimunes/patologia , Regiões Determinantes de Complementaridade , Doenças Linfáticas/patologia , Transtornos Linfoproliferativos/patologia , Receptor fas/fisiologia , Antibacterianos/uso terapêutico , Antígenos CD/metabolismo , Apoptose/genética , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Células Cultivadas , Pré-Escolar , Células Clonais , Humanos , Cadeias alfa de Imunoglobulina/genética , Imuno-Histoquímica , Imunofenotipagem , Hibridização In Situ , Leucócitos Mononucleares/imunologia , Linfonodos/patologia , Doenças Linfáticas/tratamento farmacológico , Doenças Linfáticas/genética , Doenças Linfáticas/imunologia , Transtornos Linfoproliferativos/tratamento farmacológico , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/imunologia , Masculino , Reação em Cadeia da Polimerase , Receptor fas/genética
14.
J Clin Virol ; 12(3): 201-10, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10382817

RESUMO

BACKGROUND: Natural measles virus infection as well as vaccination with attenuated measles virus induce temporary immunosuppression, which is responsible for part of the morbidity and mortality associated with measles. The underlying molecular mechanisms are not known. Recently, in vitro studies have revealed a marked increase of LFA-1 expression of lymphocytes in the presence of infectious measles virus. OBJECTIVES: In order to further investigate immune dysfunction in measles we analyzed the expression of leukocyte function-associated antigen 1 (LFA-1) on ex vivo derived circulating human T cells. STUDY DESIGN: Expression of LFA-1 was measured by flow cytometry using monoclonal antibodies directed against CD11a and CD18. LFA-1 expression was followed in the course of infection in four adult seronegative vaccinees and in four patients with natural measles. RESULTS: There was a remarkable loss of LFA-1-bright cells during natural measles and after measles vaccination. The number of LFA-1-bright cells reached a minimum on day 7-14 after vaccination, and at the onset of rash during natural measles infection, and approached normal levels within 3-5 weeks. CONCLUSION: It is suggested that measles virus infection interferes with lymphocyte trafficking and reallocation. Disruption of recirculation and random homing of lymphocytes might contribute to the immunosuppression, which is characteristic for measles virus infection.


Assuntos
Antígeno-1 Associado à Função Linfocitária/biossíntese , Sarampo/imunologia , Linfócitos T/imunologia , Adulto , Humanos , Leucócitos Mononucleares/imunologia , Ativação Linfocitária , Depleção Linfocítica , Vacina contra Sarampo/imunologia , Vírus do Sarampo , Caxumba/imunologia , Vacina contra Caxumba/imunologia , Subpopulações de Linfócitos T/imunologia , Vacinação
16.
Clin Exp Immunol ; 102(1): 40-5, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7554397

RESUMO

CD8+ cytotoxic T lymphocytes (CTL) in measles virus infection have been difficult to investigate due to the strong immunosuppressive effects exhibited by infectious measles virus in vitro. In order to circumvent immunosuppression we used predicted peptide epitopes to induce measles virus-specific CTL. This was done by screening the structural proteins of measles virus for HLA-A2.1 peptide-binding motifs with valine in position 2 and leucine in position 9. Synthetic peptides np210-218, np226-234, and np340-348 from the nucleoprotein, peptide hp29-37 from the haemagglutinin protein, and peptide pp 519-527 from the polymerase protein were synthesized and used to expand measles virus-specific CD8+ CTL in vitro. Induction of CTL with synthetic peptides was restricted to HLA-A2-positive peripheral blood mononuclear cells (PBMC) from measles-seropositive individuals. We conclude that this method is a useful tool to demonstrate memory CD8+ CTL in measles-seropositive adults and to evaluate the role of structural proteins in CTL responses against measles.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica , Vírus do Sarampo/imunologia , Fragmentos de Peptídeos/imunologia , Adulto , Sequência de Aminoácidos , Linhagem Celular , Antígeno HLA-A2/análise , Antígeno HLA-A2/imunologia , Humanos , Dados de Sequência Molecular
17.
Ann Hematol ; 71(2): 101-2, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7654853

RESUMO

We report the case of a 12-year-old boy suffering from severe low-titer cold-hemagglutinin disease with excruciating colicky abdominal pain, jaundice, and acute hemolytic anemia requiring transfusion. Cold hemagglutinins of the IgM type and a positive direct antiglobulin test, predominantly against C3d, were found. Steroid pulse therapy with 20 mg/kg body wt. methylprednisolone for 3 consecutive days was given. Abdominal pain disappeared within 12 h of the first steroid infusion and hemolysis was halted. We conclude that a therapeutic trial with steroid pulse therapy in severe low-titer cold-hemagglutinin disease is warranted.


Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Metilprednisolona/uso terapêutico , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/imunologia , Autoanticorpos/sangue , Criança , Complemento C3d/imunologia , Teste de Coombs , Humanos , Imunoglobulina M/imunologia , Masculino , Metilprednisolona/administração & dosagem
18.
Eur J Immunol ; 25(4): 976-84, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7737301

RESUMO

CD46, the major component of the measles virus (MV) receptor complex and a member of the regulators of complement activity (RCA) gene cluster, is down-regulated in MV-infected cells. We investigated whether the reduction of surface CD46 correlates with enhanced sensitivity of lymphoid and monocytic cells to lysis by activated complement. On human U937 cells, acutely or persistently infected with MV-Edmonston (ED) vaccine strain, infection-dependent down-regulation of CD46 confers sensitivity to activated complement, regardless of the pathway of activation and the specificity of the activating antibodies. Interestingly, down-regulation of CD46 alone is sufficient to confer susceptibility of cells to complement lysis despite the continued surface expression of other RCA proteins such as CD35 and CD55. In primary cultures, both peripheral blood lymphocytes and macrophages are efficiently lysed in the presence of complement activated via the alternative pathway after MV infection. In contrast to the MV-ED infection, infection of cells with the lymphotropic MV wild-type strain WTF does not down-regulate CD46. Cells infected with MV-WTF do not exhibit enhanced susceptibility to complement lysis. These data suggest that MV strains similar to WTF that do not down-regulate CD46 may have an enhanced potential for replication and dissemination within the human host, whereas complement-mediated elimination of cells infected with CD46-down-regulating strains of MV, such as ED, may limit the spread of MV infection, and could thus represent an attenuating factor for MV.


Assuntos
Antígenos CD/biossíntese , Ativação do Complemento/imunologia , Leucócitos Mononucleares/imunologia , Vírus do Sarampo/imunologia , Sarampo/imunologia , Glicoproteínas de Membrana/biossíntese , Células Cultivadas , Regulação para Baixo , Humanos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/virologia , Sarampo/sangue , Proteína Cofatora de Membrana
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