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1.
Public Health ; 183: 126-131, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32497780

RESUMEN

OBJECTIVE: Obesity is one of the most common risk factors for cardiometabolic diseases in Australia and worldwide. Recent studies show that people with normal body mass index (BMI) but with central obesity are at increased risk of morbidity and mortality from cardiometabolic diseases. This risk has not been explained well. The aim of this study was to examine the magnitude, correlates and effects of normal BMI central obesity in the Australian adult population. STUDY DESIGN: Longitudinal study with data linkage. METHODS: We used the Baker Biobank, which contains sociodemographic, behavioural, clinical and mortality data. Data were collected between 2000 and 2011 from 6530 adults who were between 18 and 69 years of age. Biobank data were linked to the National Death Index. A matrix of BMI and waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR) were used to create adiposity categories. For analysis, we used descriptive statistics, logistic regression and cox regression models. RESULTS: The overall prevalence of normal BMI central obesity was 13.4% by WHtR and 14.4% by WHR. Gender, age, BMI and physical activity were associated with normal BMI central obesity. Higher odds of multimorbidity and increased hazards of all-cause and cardiovascular mortality were associated with WHR. CONCLUSION: WHtR and WHR, when each used with BMI, provided similar estimates of prevalence of normal BMI central obesity. However, WHR is a better predictor of all-cause and cardiovascular mortality.


Asunto(s)
Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Peso Corporal Ideal , Obesidad Abdominal/epidemiología , Adolescente , Adulto , Anciano , Australia/epidemiología , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Prevalencia , Factores de Riesgo , Relación Cintura-Estatura , Relación Cintura-Cadera , Adulto Joven
2.
Eur Heart J ; 38(30): 2340-2348, 2017 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-28531281

RESUMEN

AIMS: To determine if an intensified form of heart failure management programme (INT-HF-MP) based on individual profiling is superior to standard management (SM) in reducing health care costs during 12-month follow-up (primary endpoint). METHODS AND RESULTS: A multicentre randomized trial involving 787 patients (full analysis set) discharged from four tertiary hospitals with chronic HF who were randomized to SM (n = 391) or INT-HF-MP (n = 396). Mean age was 74 ± 12 years, 65% had HF with a reduced ejection fraction (31.4 ± 8.9%) and 14% were remote-dwelling. Study groups were well matched. According to Green, Amber, Red Delineation of rIsk And Need in HF (GARDIAN-HF) profiling, regardless of location, patients in the INT-HF-MP received a combination of face-to-face (home visits) and structured telephone support (STS); only 9% (`low risk') were designated to receive the same level of management as the SM group. The median cost in 2017 Australian dollars (A$1 equivalent to ∼EUR €0.7) of applying INT-HF-MP was significantly greater than SM ($152 vs. $121 per patient per month; P < 0.001), However, at 12 months, there was no difference in total health care costs for the INT-HF-MP vs. SM group (median $1579, IQR $644 to $3717 vs. $1450, IQR $564 to $3615 per patient per month, respectively). This reflected minimal differences in all-cause mortality (17.7% vs. 18.4%; P = 0.848) and recurrent hospital stay (18.6 ± 26.5 vs. 16.6 ± 24.8 days; P = 0.199) between the INT-HF-MP and SM groups, respectively. CONCLUSION: During 12-months follow-up, an INT-HF-MP did not reduce healthcare costs or improve health outcomes relative to SM.


Asunto(s)
Insuficiencia Cardíaca/terapia , Anciano , Australia/epidemiología , Enfermedad Crónica , Femenino , Costos de la Atención en Salud , Insuficiencia Cardíaca/economía , Hospitalización/economía , Hospitalización/estadística & datos numéricos , Humanos , Masculino , Grupo de Atención al Paciente/economía , Grupo de Atención al Paciente/estadística & datos numéricos , Resultado del Tratamiento
3.
Clin Exp Immunol ; 183(3): 419-30, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26439909

RESUMEN

Killer immunoglobulin-like receptors (KIRs) interact with human leucocyte antigen (HLA) class I ligands and play a key role in the regulation and activation of NK cells. The functional importance of KIR-HLA interactions has been demonstrated for a number of chronic viral infections, but to date only a few studies have been performed in the context of acute self-limited viral infections. During our investigation of CD8(+) T cell responses to a conserved HLA-B57-restricted epitope derived from dengue virus (DENV) non-structural protein-1 (NS1), we observed substantial binding of the tetrameric complex to non-T/non-B lymphocytes in peripheral blood mononuclear cells (PBMC) from a long-standing clinical cohort in Thailand. We confirmed binding of the NS1 tetramer to CD56(dim) NK cells, which are known to express KIRs. Using depletion studies and KIR-transfected cell lines, we demonstrated further that the NS1 tetramer bound the inhibitory receptor KIR3DL1. Phenotypical analysis of PBMC from HLA-B57(+) subjects with acute DENV infection revealed marked activation of NS1 tetramer-binding natural killer (NK) cells around the time of defervescence in subjects with severe dengue disease. Collectively, our findings indicate that subsets of NK cells are activated relatively late in the course of acute DENV illness and reveal a possible role for specific KIR-HLA interactions in the modulation of disease outcomes.


Asunto(s)
Virus del Dengue/química , Dengue/inmunología , Células Asesinas Naturales/inmunología , Fragmentos de Péptidos/inmunología , Receptores KIR3DL1/inmunología , Receptores KIR3DL1/metabolismo , Proteínas no Estructurales Virales/inmunología , Enfermedad Aguda , Adolescente , Niño , Preescolar , Dengue/fisiopatología , Dengue/virología , Virus del Dengue/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Antígenos HLA-B/inmunología , Humanos , Lactante , Células Asesinas Naturales/fisiología , Leucocitos Mononucleares/inmunología , Masculino , Fragmentos de Péptidos/metabolismo , Unión Proteica , Proteínas no Estructurales Virales/metabolismo
4.
Intern Med J ; 44(4): 345-53, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24877253

RESUMEN

BACKGROUND: Weight gain and hypoglycaemia are common adverse effects associated with anti-diabetic treatments. AIM: Our aim was to evaluate the long-term effects of adjunctive exenatide therapy on weight loss and glycaemic control in patients with type 2 diabetes. METHODS: A review of medical records in a specialist diabetes clinic over 5 years identified 446 patients who were prescribed exenatide therapy. We examined change in glycosylated haemoglobin (HbA1c), weight, albumin-creatinine ratio and hypoglycaemic medication during 24 months follow up. RESULTS: Subjects were aged 59 ± 10 years (49% women) and received exenatide in combination with oral agents and insulin (47%). During an average of 17 ± 14 months follow up, 51% (more women than men; odds ratio 1.69, 95% confidence interval 1.14­2.49) remained on treatment. Lack of efficacy (33%) and/or gastrointestinal (27%) side-effects were the main reasons for treatment cessation. At 24 months, there was a reduction in HbA1c of 0.7 ± 1.2% and weight loss of 4.3 ± 5.2 kg. Change in HbA1c was similar regardless of concurrent insulin therapy, yet insulin was associated with greater weight reduction (4.8 ± 5.3 vs 3.8 ± 5.1 kg, P = 0.016). Independent predictors of HbA1c response were higher baseline HbA1c, longer duration of diabetes and use of insulin or sulfonylureas at study end. Predictors of weight response were baseline use of insulin or thiazolidinediones, increased age, female sex and sulfonylurea or thiazolidinediones at study end. Longer exenatide treatment duration was favourable for reducing HbA1c and weight. CONCLUSIONS: Exenatide is effective in reducing HbA1c and weight, regardless of concurrent insulin, and in a specialist diabetes outpatient clinic, is recommended for use in clinical practice.


Asunto(s)
Instituciones de Atención Ambulatoria , Glucemia/metabolismo , Peso Corporal/efectos de los fármacos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Tolerancia a Medicamentos , Péptidos/administración & dosificación , Ponzoñas/administración & dosificación , Diabetes Mellitus Tipo 2/sangre , Relación Dosis-Respuesta a Droga , Exenatida , Femenino , Estudios de Seguimiento , Péptido 1 Similar al Glucagón , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemiantes/administración & dosificación , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
5.
Genes Immun ; 14(5): 330-5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23636221

RESUMEN

Human leukocyte antigen (HLA) genotype has been associated with the probability of spontaneous clearance of hepatitis C virus (HCV). However, no prior studies have examined whether this relationship may be further characterized by grouping HLA alleles according to their supertypes, defined by their binding capacities. There is debate regarding the most appropriate method to define supertypes. Therefore, previously reported HLA supertypes (46 class I and 25 class II) were assessed for their relation with HCV clearance in a population of 758 HCV-seropositive women. Two HLA class II supertypes were significant in multivariable models that included: (i) supertypes with significant or borderline associations with HCV clearance after adjustment for multiple tests, and (ii) individual HLA alleles not part of these supertypes, but associated with HCV clearance in our prior study in this population. Specifically, supertype DRB3 (prevalence ratio (PR)=0.4; P=0.004) was associated with HCV persistence, whereas DR8 (PR=1.8; P=0.01) was associated with HCV clearance. Two individual alleles (B*57:01 and C*01:02) associated with HCV clearance in our prior study became nonsignificant in analysis that included supertypes, whereas B*57:03 (PR=1.9; P=0.008) and DRB1*07:01 (PR=1.7; P=0.005) retained their significance. These data provide epidemiologic support for the significance of HLA supertypes in relation to HCV clearance.


Asunto(s)
Antígenos HLA/inmunología , Antígenos HLA-B/inmunología , Subtipos Serológicos HLA-DR/inmunología , Cadenas HLA-DRB1/inmunología , Hepacivirus/inmunología , Hepatitis C/inmunología , Femenino , Antígenos HLA/clasificación , Antígenos HLA/genética , Antígenos HLA-B/genética , Subtipos Serológicos HLA-DR/genética , Cadenas HLA-DRB1/genética , Hepatitis C/genética , Hepatitis C/virología , Humanos , Análisis Multivariante , Literatura de Revisión como Asunto
6.
Haemophilia ; 19(1): 113-8, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22958194

RESUMEN

Ancestral background, specifically African descent, confers higher risk for development of inhibitory antibodies to factor VIII (FVIII) in haemophilia A. It has been suggested that differences in the distribution of FVIII gene (F8) haplotypes, and mismatch between endogenous F8 haplotypes and those comprising products used for treatment could contribute to risk. Data from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort were used to determine the association between F8 haplotype 3 (H3) vs. haplotypes 1 and 2 (H1 + H2) and inhibitor risk among individuals of genetically determined African descent. Other variables known to affect inhibitor risk including type of F8 mutation and human leucocyte antigen (HLA) were included in the analysis. A second research question regarding risk related to mismatch in endogenous F8 haplotype and recombinant FVIII products used for treatment was addressed. Haplotype 3 was associated with higher inhibitor risk among those genetically identified (N = 49) as of African ancestry, but the association did not remain significant after adjustment for F8 mutation type and the HLA variables. Among subjects of all racial ancestries enrolled in HIGS who reported early use of recombinant products (N = 223), mismatch in endogenous haplotype and the FVIII proteins constituting the products used did not confer greater risk for inhibitor development. Haplotype 3 was not an independent predictor of inhibitor risk. Furthermore, our findings did not support a higher risk of inhibitors in the presence of a haplotype mismatch between the FVIII molecule infused and that of the individual.


Asunto(s)
Inhibidores de Factor de Coagulación Sanguínea/sangre , Factor VIII/genética , Haplotipos/genética , Hemofilia A/genética , Autoanticuerpos/sangre , Estudios de Cohortes , Análisis Mutacional de ADN , Factor VIII/antagonistas & inhibidores , Predisposición Genética a la Enfermedad , Hemofilia A/inmunología , Humanos , Mutación
7.
Nat Genet ; 15(1): 83-6, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8988174

RESUMEN

In higher eukaryotes, cell cycle progression is controlled by cyclin dependent kinases (Cdks) complexed with cyclins. A-type cyclins are involved at both G1/S and G2/M transitions of the cell cycle. Cyclin A2 activates cdc2 (Cdk1) on passage into mitosis and Cdk2 at the G1/S transition. Antisense constructs, or antibodies directed against cyclin A2 block cultured mammalian cells at both of these transitions. In contrast, overexpression of cyclin A2 appears to advance S phase entry and confer anchorage-independent growth, and can lead to apoptosis. A second A-type cyclin, cyclin A1 has been described recently which, in the mouse, is expressed in germ cells but not somatic tissues. To address the possible redundancy between different cyclins in vivo and also the control of early embryonic cell cycles, we undertook the targeted deletion of the murine cyclin A2 gene. The homozygous null mutant is embryonically lethal, demonstrating that the cyclin A2 gene is essential. Surprisingly, homozygous null mutant embryos develop normally until post-implantation, around day 5.5 p.c. This observation may be explained by the persistence of a maternal pool of cyclin A2 protein until at least the blastocyst stage, or an unexpected role for cyclin A1 during early embryo development.


Asunto(s)
Ciclo Celular/fisiología , Ciclina A , Ciclinas/fisiología , Desarrollo Embrionario y Fetal/fisiología , Animales , Blastocisto/fisiología , Ciclo Celular/genética , Clonación Molecular , Ciclinas/genética , Embrión de Mamíferos/citología , Embrión de Mamíferos/fisiología , Desarrollo Embrionario y Fetal/genética , Femenino , Muerte Fetal/genética , Marcación de Gen , Genes Letales , Masculino , Ratones , Células Madre
8.
Immunogenetics ; 64(2): 143-52, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21850526

RESUMEN

The activity of natural killer cells depends on the balance between activating and inhibitory signals coming from their receptors. Among these are the killer cell immunoglobulin-like receptors (KIR) that recognize specific HLA class I allotypes. Here we characterized KIR genetic diversity and their HLA ligands in the population of Curitiba, Paraná State (n = 164), and compared it with other worldwide populations. The distribution of 2DL4 alleles was also analyzed. The Curitiba population did not differ significantly from European and Euro-descendant populations, but as an admixed population showed higher genetic diversity. We found 27 KIR profiles, many of them uncommon in European populations, in agreement with the elevated historically recent gene flow in the study population. The frequencies of KIR genes and their respective HLA ligands were distributed independently and none of the analyzed individuals lacked functional KIR-HLA ligand combinations. KIR gene frequencies of 33 worldwide populations were consistent with geographic and ethnic distribution, in agreement with demography being the major factor shaping the observed gene content diversity of the KIR locus.


Asunto(s)
Variación Genética , Receptores KIR/genética , Población Urbana/estadística & datos numéricos , Brasil , Etnicidad/genética , Frecuencia de los Genes , Haplotipos , Humanos , Familia de Multigenes
9.
J Clin Microbiol ; 50(6): 2173-5, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22495564

RESUMEN

We report a fatal case of Brucella suis endocarditis initially misdiagnosed by automated identification systems as Ochrobactrum anthropi infection in a patient with a history of Marfan syndrome and recreational feral swine hunting. This report emphasizes the need to consider brucellosis as a part of the differential diagnosis of acute febrile illness, particularly in patients with known risk of exposure.


Asunto(s)
Brucella suis/aislamiento & purificación , Brucelosis/diagnóstico , Errores Diagnósticos , Endocarditis Bacteriana/diagnóstico , Síndrome de Marfan/complicaciones , Automatización/métodos , Técnicas Bacteriológicas/métodos , Brucelosis/microbiología , Brucelosis/patología , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/patología , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad , Ochrobactrum anthropi/aislamiento & purificación
10.
Bioact Mater ; 8: 325-340, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34541404

RESUMEN

Ag/Ga were incorporated into resorbable orthopaedic phosphate bioactive glasses (PBG, containing P, Ca, Mg, Na, and Fe) thin films to demonstrate their potential to limit growth of Staphylococcus aureus and Escherichia coli in post-operative prosthetic implantation. Dual target consecutive co-sputtering was uniquely employed to produce a 46 nm Ag:PBG composite observed by high resolution TEM to consist of uniformly dispersed ~5 nm metallic Ag nano-particles in a glass matrix. Ga3+ was integrated into a phosphate glass preform target which was magnetron sputtered to film thicknesses of ~400 or 1400 nm. All coatings exhibited high surface energy of 75.4-77.3 mN/m, attributed to the presence of hydrolytic P-O-P structural surface bonds. Degradation profiles obtained in deionized water, nutrient broth and cell culture medium showed varying ion release profiles, whereby Ga release was measured in 1400 nm coating by ICP-MS to be ~6, 27, and 4 ppm respectively, fully dissolving by 24 h. Solubility of Ag nanoparticles was only observed in nutrient broth (~9 ppm by 24 h). Quantification of colony forming units after 24 h showed encouraging antibacterial efficacy towards both S. aureus (4-log reduction for Ag:PBG and 6-log reduction for Ga-PBG≈1400 nm) and E. coli (5-log reduction for all physical vapour deposited layers) strains. Human Hs27 fibroblast and mesenchymal stem cell line in vitro tests indicated good cytocompatibility for all sputtered layers, with a marginal cell proliferation inertia in the case of the Ag:PBG composite thin film. The study therefore highlights the (i) significant manufacturing development via the controlled inclusion of metallic nanoparticles into a PBG glass matrix by dual consecutive target co-sputtering and (ii) potential of PBG resorbable thin-film structures to incorporate and release cytocompatible/antibacterial oxides. Both architectures showed prospective bio-functional performance for a future generation of endo-osseous implant-type coatings.

11.
J Virol ; 84(11): 5540-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20335261

RESUMEN

Effective HIV-specific T-cell immunity requires the ability to inhibit virus replication in the infected host, but the functional characteristics of cells able to mediate this effect are not well defined. Since Gag-specific CD8 T cells have repeatedly been associated with lower viremia, we examined the influence of Gag specificity on the ability of unstimulated CD8 T cells from chronically infected persons to inhibit virus replication in autologous CD4 T cells. Persons with broad (>or=6; n = 13) or narrow (

Asunto(s)
Linfocitos T CD8-positivos/inmunología , VIH-1/inmunología , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/inmunología , Linfocitos T CD4-Positivos/virología , Células Cultivadas , Infecciones por VIH/inmunología , Humanos , Especificidad del Receptor de Antígeno de Linfocitos T , Replicación Viral
13.
Nat Med ; 2(4): 405-11, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8597949

RESUMEN

Major histocompatibility complex (MHC) genes (HLA in humans) regulate the immune response to foreign antigens. Molecular and serologic techniques were used to identify products of HLA class I, class II and transporter (TAP) genes (also part of the MHC) in homosexual seroconverters to human immunodeficiency virus type 1 (HIV-1). Comprehensive statistical analysis produced an HLA profile that predicted time from HIV-1 infection to the onset of AIDS. The profile was developed in a cohort of 139 men and evaluated in a second unrelated cohort of 102 men. In the evaluation cohort, the profile discriminated a sixfold difference between groups with the shortest and longest times to AIDS (P = 0.001). These findings support current theory about control of antigen processing by HLA genes and have implications for immunopathogenesis of HIV-1 and other infections.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/inmunología , Infecciones por VIH/genética , VIH-1/aislamiento & purificación , Complejo Mayor de Histocompatibilidad/genética , Estudios de Cohortes , Ligamiento Genético , Infecciones por VIH/inmunología , Infecciones por VIH/mortalidad , Antígenos de Histocompatibilidad Clase I/análisis , Antígenos de Histocompatibilidad Clase II/análisis , Humanos , Masculino , Análisis de Supervivencia
14.
Nat Commun ; 12(1): 1153, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608536

RESUMEN

Zaire ebolavirus (EBOV) is a highly pathogenic filovirus which can result in Ebola virus disease (EVD); a serious medical condition that presents as flu like symptoms but then often leads to more serious or fatal outcomes. The 2013-16 West Africa epidemic saw an unparalleled number of cases. Here we show characterisation and identification of T cell epitopes in surviving patients from Guinea to the EBOV glycoprotein. We perform interferon gamma (IFNγ) ELISpot using a glycoprotein peptide library to identify T cell epitopes and determine the CD4+ or CD8+ T cell component response. Additionally, we generate data on the T cell phenotype and measure polyfunctional cytokine secretion by these antigen specific cells. We show candidate peptides able to elicit a T cell response in EBOV survivors and provide inferred human leukocyte antigen (HLA) allele restriction. This data informs on the long-term T cell response to Ebola virus disease and highlights potentially important immunodominant peptides.


Asunto(s)
Ebolavirus/inmunología , Epítopos de Linfocito T/inmunología , Glicoproteínas/inmunología , Fiebre Hemorrágica Ebola/inmunología , Linfocitos T/inmunología , África Occidental/epidemiología , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Ebolavirus/genética , Ensayo de Immunospot Ligado a Enzimas , Epidemias , Glicoproteínas/genética , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Inmunidad Celular , Interferón gamma , Sobrevivientes
15.
Genes Immun ; 11(4): 334-42, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20072141

RESUMEN

We have conducted a comprehensive case-control study of a nasopharyngeal carcinoma (NPC) population cohort from Guangxi Province of Southern China, a region with one of the highest NPC incidences on record. A total of 1407 individuals including NPC patients, healthy controls, and their adult children were examined for the human leukocyte antigen (HLA) association, which is so far the largest NPC cohort reported for such studies. Stratified analysis performed in this study clearly demonstrated that while NPC protection is associated with independent HLA alleles, most NPC susceptibility is strictly associated with HLA haplotypes. Our study also detected for the first time that A(*)0206, a unique A2 subtype to South and Southeast Asia is also associated with a high risk for NPC. HLA-A(*)0206, HLA-B(*)3802 alleles plus the A(*)0207-B(*)4601 and A(*)3303-B(*)5801 haplotypes conferred high risk for NPC showing a combined odds ratio (OR) of 2.6 (P<0.0001). HLA alleles that associate with low risk for NPC include HLA-A(*)1101, B(*)27, and B(*)55 with a combined OR of 0.42 (P<0.0001). The overall high frequency of NPC-susceptible HLA factors in the Guangxi population is likely to have contributed to the high-NPC incidence in this region.


Asunto(s)
Antígenos HLA/genética , Haplotipos , Neoplasias Nasofaríngeas/genética , Alelos , Estudios de Casos y Controles , China/epidemiología , Estudios de Cohortes , Humanos , Incidencia , Neoplasias Nasofaríngeas/epidemiología , Neoplasias Nasofaríngeas/etnología
16.
J Exp Med ; 193(6): 671-8, 2001 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-11257134

RESUMEN

The discovery of dendritic cell (DC)-specific intercellular adhesion molecule (ICAM)-3-grabbing nonintegrin (DC-SIGN) as a DC-specific ICAM-3 binding receptor that enhances HIV-1 infection of T cells in trans has indicated a potentially important role for adhesion molecules in AIDS pathogenesis. A related molecule called DC-SIGNR exhibits 77% amino acid sequence identity with DC-SIGN. The DC-SIGN and DC-SIGNR genes map within a 30-kb region on chromosome 19p13.2-3. Their strong homology and close physical location indicate a recent duplication of the original gene. Messenger RNA and protein expression patterns demonstrate that the DC-SIGN-related molecule is highly expressed on liver sinusoidal cells and in the lymph node but not on DCs, in contrast to DC-SIGN. Therefore, we suggest that a more appropriate name for the DC-SIGN-related molecule is L-SIGN, liver/lymph node-specific ICAM-3-grabbing nonintegrin. We show that in the liver, L-SIGN is expressed by sinusoidal endothelial cells. Functional studies indicate that L-SIGN behaves similarly to DC-SIGN in that it has a high affinity for ICAM-3, captures HIV-1 through gp120 binding, and enhances HIV-1 infection of T cells in trans. We propose that L-SIGN may play an important role in the interaction between liver sinusoidal endothelium and trafficking lymphocytes, as well as function in the pathogenesis of HIV-1.


Asunto(s)
Antígenos CD , Antígenos de Diferenciación , Moléculas de Adhesión Celular/metabolismo , Proteína gp120 de Envoltorio del VIH/metabolismo , VIH-1/fisiología , Lectinas Tipo C , Lectinas/fisiología , Hígado/metabolismo , Receptores de Antígenos/fisiología , Receptores del VIH/fisiología , Receptores Virales/fisiología , Animales , Secuencia de Bases , Línea Celular , Células Cultivadas , Mapeo Cromosómico , ADN Complementario , Células Dendríticas , Endotelio/citología , Exones , VIH-1/metabolismo , Humanos , Lectinas/genética , Lectinas/metabolismo , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Polimorfismo Genético , Receptores de Antígenos/genética , Receptores de Antígenos/metabolismo , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores del VIH/genética , Receptores del VIH/metabolismo
17.
J Virol ; 83(3): 1228-39, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19019964

RESUMEN

Human immunodeficiency virus type 1 (HIV-1) can evade immunity shortly after transmission to a new host but the clinical significance of this early viral adaptation in HIV infection is not clear. We present an analysis of sequence variation from a longitudinal cohort study of HIV adaptation in 189 acute seroconverters followed for up to 3 years. We measured the rates of variation within well-defined epitopes to determine associations with the HLA-linked hazard of disease progression. We found early reversion across both the gag and pol genes, with a 10-fold faster rate of escape in gag (2.2 versus 0.27 forward mutations/1,000 amino acid sites). For most epitopes (23/34), variation in the HLA-matched and HLA-unmatched controls was similar. For a minority of epitopes (8/34, and generally associated with HLA class I alleles that confer clinical benefit), new variants appeared early and consistently over the first 3 years of infection. Reversion occurred early at a rate which was HLA-dependent and correlated with the HLA class 1-associated relative hazard of disease progression and death (P = 0.0008), reinforcing the association between strong cytotoxic T-lymphocyte responses, viral fitness, and disease status. These data provide a comprehensive overview of viral adaptation in the first 3 years of infection. Our findings of HLA-dependent reversion suggest that costs are borne by some escape variants which may benefit the host, a finding contrary to a simple immune evasion paradigm. These epitopes, which are both strongly and frequently recognized, and for which escape involves a high cost to the virus, have the potential to optimize vaccine design.


Asunto(s)
Epítopos/inmunología , Infecciones por VIH/inmunología , Antígenos HLA/inmunología , Secuencia de Aminoácidos , Estudios de Cohortes , Progresión de la Enfermedad , Epítopos/química , Genes MHC Clase I , Genes gag , Genes pol , VIH/genética , Humanos
18.
Tissue Antigens ; 75(6): 724-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20210918

RESUMEN

This study represents the first report on the distribution of KIR genes in 205 unrelated healthy mestizo Venezuelan individuals. Genotyping analysis showed that all KIR genes are present in this population. Frequency of inhibitory killer cell immunoglobulin-like receptors (KIRs) exceeded 0.69, except for KIR2DL2 (0.29) and 2DL5 (0.37). Activating KIRs showed low frequencies (0.11-0.29), except for KIR2DS4 (0.68). Forty-five different KIR genotypes were identified, with a predominance of three genotypes found in 50.7% of the population of which 25.9% were individuals homozygous for haplotype A. The frequencies of KIR genes reflect the ethnic admixture existing in the mestizo Venezuelan population.


Asunto(s)
Frecuencia de los Genes , Población/genética , Receptores KIR/genética , Humanos , Filogenia , Venezuela
19.
J Cell Biol ; 139(1): 103-14, 1997 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-9314532

RESUMEN

In the mammalian host, the cell surface of Trypanosoma brucei is protected by a variant surface glycoprotein that is anchored in the plasma membrane through covalent attachment of the COOH terminus to a glycosylphosphatidylinositol. The trypanosome also contains a phospholipase C (GPI-PLC) that cleaves this anchor and could thus potentially enable the trypanosome to shed the surface coat of VSG. Indeed, release of the surface VSG can be observed within a few minutes on lysis of trypanosomes in vitro. To investigate whether the ability to cleave the membrane anchor of the VSG is an essential function of the enzyme in vivo, a GPI-PLC null mutant trypanosome has been generated by targeted gene deletion. The mutant trypanosomes are fully viable; they can go through an entire life cycle and maintain a persistent infection in mice. Thus the GPI-PLC is not an essential activity and is not necessary for antigenic variation. However, mice infected with the mutant trypanosomes have a reduced parasitemia and survive longer than those infected with control trypanosomes. This phenotype is partially alleviated when the null mutant is modified to express low levels of GPI-PLC.


Asunto(s)
Glicosilfosfatidilinositoles/fisiología , Parasitemia/enzimología , Trypanosoma brucei brucei/enzimología , Tripanosomiasis Africana/enzimología , Fosfolipasas de Tipo C/fisiología , Animales , Modelos Animales de Enfermedad , Glicosilfosfatidilinositoles/genética , Ratones , Ratones Endogámicos , Mutagénesis Insercional , Parasitemia/genética , Parasitemia/parasitología , Fenotipo , Eliminación de Secuencia , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/crecimiento & desarrollo , Tripanosomiasis Africana/genética , Tripanosomiasis Africana/parasitología , Fosfolipasas de Tipo C/biosíntesis , Fosfolipasas de Tipo C/genética
20.
Science ; 283(5408): 1748-52, 1999 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-10073943

RESUMEN

A selective advantage against infectious disease associated with increased heterozygosity at the human major histocompatibility complex [human leukocyte antigen (HLA) class I and class II] is believed to play a major role in maintaining the extraordinary allelic diversity of these genes. Maximum HLA heterozygosity of class I loci (A, B, and C) delayed acquired immunodeficiency syndrome (AIDS) onset among patients infected with human immunodeficiency virus-type 1 (HIV-1), whereas individuals who were homozygous for one or more loci progressed rapidly to AIDS and death. The HLA class I alleles B*35 and Cw*04 were consistently associated with rapid development of AIDS-defining conditions in Caucasians. The extended survival of 28 to 40 percent of HIV-1-infected Caucasian patients who avoided AIDS for ten or more years can be attributed to their being fully heterozygous at HLA class I loci, to their lacking the AIDS-associated alleles B*35 and Cw*04, or to both.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/inmunología , Genes MHC Clase I , Infecciones por VIH/inmunología , VIH-1 , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Síndrome de Inmunodeficiencia Adquirida/genética , Adulto , Alelos , Presentación de Antígeno , Estudios de Cohortes , Progresión de la Enfermedad , Etnicidad , Predisposición Genética a la Enfermedad , Infecciones por VIH/genética , Sobrevivientes de VIH a Largo Plazo/estadística & datos numéricos , Antígenos HLA/genética , Heterocigoto , Homocigoto , Humanos , Células Asesinas Naturales/inmunología , Pérdida de Heterocigocidad , Modelos de Riesgos Proporcionales , Riesgo
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