Epitope of dengue virus E protein detect human antibodies associated with mild disease: a potential peptide for vaccine development

ABSTRACT The antigenic potential of seven immunogenic peptides of the dengue virus was evaluated in the sera of patients with dengue confirmed by IgM/IgG serology. Antibodies IgM and IgG against dengue virus peptides were analyzed by ELISA in 31 dengue sero-positive and 20 sero-negative patients. The P5 peptide showed significant IgG immunoreactivity mostly in the sera of patients with dengue without warning signs in comparison with patients with dengue with warning signs, correlating with mild disease. This finding suggests that the low antibody response against P5 epitope could be a risk factor for higher susceptibility to dengue virus infection with warning signs, and that P5 could be a potential antigen for vaccine development.

Use of a commercial ELISA kit specific for glycoprotein E peptides to indirectly detect Caprine Herpesvirus 1 (CpHV-1) in the state of São Paulo, Brazil / Uso de kit ELISA comercial específico para peptídeos da glicoproteína E para detecção indireta de Herpesvírus Caprino tipo 1 (CpHv-1) no estado de São Paulo, Brasil

Caprine herpesvirus 1 (CpHV-1) infection is associated with clinical manifestations related to animal age, with high mortality in kids and infertility in adults. Given the scarcity of research about the epidemiological situation of this infection in Brazilian flocks, we aimed to conduct a cross-sectional descriptive study to detect antibodies against CpHV-1 in goats in the state of São Paulo, Brazil. Fifty-five male and female goats ­ kids and adult ­ were assessed in this study. Blood serum was analyzed by a commercial ELISA kit to detect antibodies against CpHV-1, which had not been used in Brazil before. No animals were reactive. Brazil lacks information about CpHV-1 infection in goat flocks. Continuing the study is crucial to understand the epidemiological situation of the disease and establish protocols for infection control.(AU)

A infecção pelo Herpesvírus Caprino tipo 1 (CpHv-1) está associada a manifestações clínicas relacionadas à idade dos animais, com alta mortalidade em filhotes e infertilidade em adultos. Diante da escassez de estudos sobre situação epidemiológica dessa infecção nos rebanhos brasileiros, a presente pesquisa teve como objetivo realizar um estudo transversal e descritivo para a detecção de anticorpos anti-Herpesvírus Caprino tipo 1 em caprinos do estado de São Paulo, Brasil. Foram avaliados 55 caprinos machos e fêmeas, filhotes e adultos. O soro sanguíneo foi analisado por um kit ELISA comercial para detecção de anticorpos contra CpHv-1, de utilização inédita no Brasil. Nenhum animal estudado foi sororreagente. O Brasil carece de informações acerca da infecção pelo Herpesvírus Caprino tipo 1 nos rebanhos caprinos do país. A continuidade do estudo é imprescindível para compreender a situação epidemiológica da enfermidade e estabelecer protocolos para controle da infecção.(AU)

Péptidos inmunogénicos del gluten en deposiciones: nuevo método para evaluar la adherencia a la dieta en pacientes celíacos / Immunogenic gluten peptides in stools: new method to evaluate in the dietary adherence in celiac patients

Celiac disease (CD) is an autoimmune pathology caused by the ingestion of gluten in genetically susceptible people, currently considered multisystemic. The treatment of CD is a lifelong strict Gluten-Free Diet (GFD), which allows a symptomatic improvement in most patients and achieve intestinal mucosa healing confirmed with histological study. The adherence to the GFD is variable, arguing as possible factors related to failure the economic, cultural, social aspects and the consumption of gluten inadvertently. The management of celiac patients contemplates instructing in the proper follow-up of GFD and evaluating their adherence. So far, the only way to assess adherence to GFD is through surveys, self-reports of eating habits and serology, being the main disadvantage the subjectivity factor. Recently the immunogenic gluten peptides have acquired relevance for the objective evaluation of the adherence to the GFD and the measurement appears as an efficient and sensitive option to determine the gluten intake, providing relevant information for the clinical management.

Pesticide exposure and health conditions of terrestrial pesticide applicators in Córdoba Province, Argentina / Exposición a plaguicidas y condiciones de salud de agroaplicadores terrestres de la Provincia de Córdoba, Argentina / Exposição aos agrotóxicos e condições de saúde dos aplicadores de pesticidas da Província de Córdoba, Argentina

Agricultural workers represent a population that is highly vulnerable to the toxic effects of pesticide exposure. This cross sectional study aimed to describe the health conditions of terrestrial pesticide applicators in Córdoba Province, Argentina, their work practices and socio-demographic characteristics, by means of a standardized self-administered questionnaire (n = 880). A descriptive analysis reported a high prevalence of occasional or frequent symptoms: 47.4% had symptoms of irritation, 35.5% fatigue, 40.4% headache and 27.6% nervousness or depression. Using logistic regression models, risk and protective factors were found for symptoms of irritation, medical consultation and hospitalization. Among the occupational exposure variables, marital status, length of time in the job, low level of protection with regard to the use of personal protective equipment, combined use of different pesticides and the application of the insecticide endosulfan, were associated with a higher frequency of reported symptoms and higher consultation rates and hospitalization.

Los trabajadores agrícolas son una población altamente vulnerable a los efectos tóxicos de la exposición a plaguicidas. Con el objetivo de describir las condiciones de salud de agroaplicadores terrestres de plaguicidas de la Provincia de Córdoba, Argentina, sus prácticas laborales y características sociodemográficas, se realizó un estudio transversal, mediante cuestionario (n = 880). Un análisis descriptivo reportó alta prevalencia de sintomatología ocasional o frecuente: 47,4% síntomas irritativos, 35,5% cansancio, 40,4% cefalea y 27,6% ansiedad o depresión. Mediante modelos logísticos se detectaron factores protectores y de riesgo que explican la presencia de síntomas irritativos, la consulta médica y la hospitalización. El estado civil, la antigüedad en la tarea, el nivel de protección considerando uso de equipo de protección personal, la exposición múltiple a plaguicidas y la aplicación del insecticida endosulfán, se asociaron a mayor frecuencia de reporte de síntomas, consultas médicas y hospitalizaciones por causas relacionadas con la exposición a plaguicidas.

Os trabalhadores agrícolas são uma população altamente vulnerável aos efeitos tóxicos da exposição a pesticidas. Este estudo transversal teve o objetivo de descrever as condições de saúde de aplicadores terrestres de pesticidas da Província de Córdoba, Argentina, suas práticas de trabalho e características sociodemográficas, por meio de um questionário padronizado autoadministrado (n = 880). A análise descritiva relatou alta prevalência de sintomas ocasionais ou frequentes: 47,4% sintomas irritativos, 35,5% fadiga, 40,4% dor de cabeça e 27,6% ansiedade ou depressão. Mediante modelos logísticos foram detectados os fatores protetores e do risco que explicam a presença de sintomas irritativos, consulta médica e hospitalização. O estado civil, anos de trabalho, o nível de proteção considerando o uso de equipamentos de proteção individual, a exposição a vários pesticidas e aplicação do inseticida endosulfan, foram associados com maior frequência de sintomas, consultas médicas e hospitalização por causas relacionadas à exposição ao agrotóxico.

Immunologic evaluation and validation of methods using synthetic peptides derived from Mycobacterium tuberculosis for the diagnosis of tuberculosis infection

The goal of this study was to demonstrate the usefulness of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of pulmonary tuberculosis (PTB) and extrapulmonary TB (EPTB). This assay used 20 amino acid-long, non-overlapped synthetic peptides that spanned the complete Mycobacterium tuberculosis ESAT-6 and Ag85A sequences. The validation cohort consisted of 1,102 individuals who were grouped into the following five diagnostic groups: 455 patients with PTB, 60 patients with EPTB, 40 individuals with non-EPTB, 33 individuals with leprosy and 514 healthy controls. For the PTB group, two ESAT-6 peptides (12033 and 12034) had the highest sensitivity levels of 96.9% and 96.2%, respectively, and an Ag85A-peptide (29878) was the most specific (97.4%) in the PTB groups. For the EPTB group, two Ag85A peptides (11005 and 11006) were observed to have a sensitivity of 98.3% and an Ag85A-peptide (29878) was also the most specific (96.4%). When combinations of peptides were used, such as 12033 and 12034 or 11005 and 11006, 99.5% and 100% sensitivities in the PTB and EPTB groups were observed, respectively. In conclusion, for a cohort that consists entirely of individuals from Venezuela, a multi-antigen immunoassay using highly sensitive ESAT-6 and Ag85A peptides alone and in combination could be used to more rapidly diagnose PTB and EPTB infection.

Development of a peptide based latex agglutination assay for serotype identification of foot and mouth disease virus.

Out of 200 serum samples collected from cattle (142) and buffaloes (58) of various ages and sexand subjected to latex agglutination test (LAT) using serotype specific peptides (O, A, Asia 1) and also with peptide for non-structural protein 2B (NSP-2B), 114 (70%) samples were positive against FMDV type ‘O’, 102 (51%) against serotype ‘A’ and 104 (52%) against serotype ‘Asia 1’. With NSP-2B peptide a total of 71 (35.5%) samples were positive. The results suggest that LAT could be used for the diagnosis of foot and mouth disease virus as it is easy, cheap and effective test.

Anti-peptide antibodies: a tool for detecting IL-8 in salmonids

Background: Interleukin 8 is a chemokine that is produced by several types of cells, like macrophages and has chemotactic activity in particular on neutrophils, playing a key role during the inflammatory process. It has been demonstrated at the molecular level that this molecule is present and conserved in several vertebrate groups, pointing its importance. Analysis of the amino acid sequence of IL-8, projected from cDNA of Salmo salar, presents homology with the sequences of mammals, poultry and lamprey, indicating the presence of a homologous molecule in higher fish. However, there is no information at protein level, which allows characterizing the regulatory role of this molecule during the immune response in fish. Results: In this work, we designed and synthesized an epitope peptide of 10 residues with a purity of 95 percent and mass of 1158.7 kDa, which showed a random coil structure. From this peptide it was able to generate a polyclonal mono-specific antibody which was capable of detecting the whole molecule of IL-8 in tissue and cellular model of salmonids. Conclusions: The resulting antibody is a versatile tool for detecting IL-8 by different immune techniques such as ELISA, dot blot, western blotting and immunocytofluorescence. Analysis of IL-8 at proteomic level is a useful method for characterizing immune properties of this molecule in fish.

Aprimoramento da anotação N-terminal de proteínas através da predição de peptídeo sinal em proteínas ortólogase desenvolvimento de uma ferramenta automática para a identificação de grupos ortólogos contendo erros deanotação

O peptídeo sinal é um motivo encontrado, geralmente, na extremidade N-terminal deproteínas e a sua presença determina a entrada na via clássica de transporte intracelular,após a translocação da proteína para o lúmen do retículo endoplasmático. Portanto, apresença ou ausência do peptídeo sinal influencia a função biológica de uma proteína ao serum fator determinante da sua localização subcelular. Como a conservação de função entreproteínas ortólogas é esperada, foi hipotetizado que a localização subcelular e,consequentemente, a presença do peptídeo sinal deveriam, também, se apresentarconservadas. Partindo desta premissa, as predições de peptídeo sinal em proteínasortólogas de cinco espécies de Plasmodium foram analisadas.Predições de peptídeo sinal (SignalP) e informações de ortologia (OrthoMCL-DB)para proteínas de cinco espécies do gênero Plasmodium (Plasmodium falciparum,Plasmodium vivax, Plasmodium knowlesi, Plasmodium berguei e Plasmodium yoelii) foramcombinadas em uma estratégia inovadora, visando a identificação de grupos de proteínasortólogas que apresentam predições de peptídeo sinal divergentes (grupos Mistos).

Asproteínas pertencentes a estes grupos foram submetidas a uma análise comparativabaseada na inspeção visual de alinhamentos múltiplos e de modelos gênicos e regiõesgenômicas flanqueadoras da extremidade N-terminal. Novos modelos gênicos foramsugeridos para aquelas proteínas que apresentavam prováveis erros de anotação desequência, especialmente na região N-terminal. Alguns dos novos modelos gênicos foramvalidados por RT-PCR. Os resultados da inspeção visual foram usados para treinar umaMáquina de Suporte de Vetores (Support Vector Machine) com o objetivo de classificargrupos Mistos em: (1) Com erros de anotação ou (2) Sem erros de anotação. O SVM foiaplicado para classificar os grupos Mistos de cinco bancos de dados, montados a partir devinte e duas espécies.Os grupos contendo proteínas com predições de peptídeo sinal divergentesapresentaram uma alta taxa de erros de anotação. Um total de 478 proteínas dePlasmodium foram reanotadas sendo que a maioria apresentou inversões das suaspredições de peptídeo sinal originais, representando um impacto significativo no conjuntofinal de proteínas destinadas à via clássica de transporte intracelular, principalmente paraPlasmodium vivax e Plasmodium yoelii. O classificador baseado nos dados da inspeçãovisual se mostrou bastante flexível e robusto, apresentando uma performance boa econsistente mesmo frente a cenários variados de agrupamento de espécies.A metodologia proposta introduz uma abordagem simples, porém promissora, para arealização de tarefas de curadoria e controle de qualidade dos dados de anotação desequências proteicas em uma escala genômica. Os resultados do classificador definem a base para seu desenvolvimento em uma ferramenta computacional e os resultados dasreanotações em Plasmodium impactarão a busca por novos alvos vacinais equimioterápicos.

Aprimoramento da anotação N-terminal de proteínas através da predição de peptídeo sinal em proteínas ortólogase desenvolvimento de uma ferramenta automática para a identificação de grupos ortólogos contendo erros deanotação / Improved annotation of N-terminal protein through the prediction of signal peptide in orthologous proteins and developing a tool for automatic Identification of orthologs groups containing errors annotation

O peptídeo sinal é um motivo encontrado, geralmente, na extremidade N-terminal deproteínas e a sua presença determina a entrada na via clássica de transporte intracelular,após a translocação da proteína para o lúmen do retículo endoplasmático. Portanto, apresença ou ausência do peptídeo sinal influencia a função biológica de uma proteína ao serum fator determinante da sua localização subcelular. Como a conservação de função entreproteínas ortólogas é esperada, foi hipotetizado que a localização subcelular e,consequentemente, a presença do peptídeo sinal deveriam, também, se apresentarconservadas. Partindo desta premissa, as predições de peptídeo sinal em proteínasortólogas de cinco espécies de Plasmodium foram analisadas.Predições de peptídeo sinal (SignalP) e informações de ortologia (OrthoMCL-DB)para proteínas de cinco espécies do gênero Plasmodium (Plasmodium falciparum,Plasmodium vivax, Plasmodium knowlesi, Plasmodium berguei e Plasmodium yoelii) foramcombinadas em uma estratégia inovadora, visando a identificação de grupos de proteínasortólogas que apresentam predições de peptídeo sinal divergentes (grupos Mistos).

Asproteínas pertencentes a estes grupos foram submetidas a uma análise comparativabaseada na inspeção visual de alinhamentos múltiplos e de modelos gênicos e regiõesgenômicas flanqueadoras da extremidade N-terminal. Novos modelos gênicos foramsugeridos para aquelas proteínas que apresentavam prováveis erros de anotação desequência, especialmente na região N-terminal. Alguns dos novos modelos gênicos foramvalidados por RT-PCR. Os resultados da inspeção visual foram usados para treinar umaMáquina de Suporte de Vetores (Support Vector Machine) com o objetivo de classificargrupos Mistos em: (1) Com erros de anotação ou (2) Sem erros de anotação. O SVM foiaplicado para classificar os grupos Mistos de cinco bancos de dados, montados a partir devinte e duas espécies.Os grupos contendo proteínas com predições de peptídeo sinal divergentesapresentaram uma alta taxa de erros de anotação. Um total de 478 proteínas dePlasmodium foram reanotadas sendo que a maioria apresentou inversões das suaspredições de peptídeo sinal originais, representando um impacto significativo no conjuntofinal de proteínas destinadas à via clássica de transporte intracelular, principalmente paraPlasmodium vivax e Plasmodium yoelii. O classificador baseado nos dados da inspeçãovisual se mostrou bastante flexível e robusto, apresentando uma performance boa econsistente mesmo frente a cenários variados de agrupamento de espécies.A metodologia proposta introduz uma abordagem simples, porém promissora, para arealização de tarefas de curadoria e controle de qualidade dos dados de anotação desequências proteicas em uma escala genômica. Os resultados do classificador definem a base para seu desenvolvimento em uma ferramenta computacional e os resultados dasreanotações em Plasmodium impactarão a busca por novos alvos vacinais equimioterápicos.

Prolonged expression of MHC class I - peptide expression in bone marrow derived retrovirus transfected matured dendritic cells by continuous centrifugation in the presence of IL-4.

Background & objectives: Dendritic cells (DCs) are potent antigen presenting cells which proceed from immature to a mature stage during their differentiation. There are several methods of obtaining long lasting mature antigen expressing DCs and different methods show different levels of antigen expressions. We investigated bone marrow derived DCs for the degree of maturation and genetically engineered antigen presentation in the presence of interleukin-4 (IL-4) as a maturity enhancer. Methods: DCs and transfected retrovirus were cultured together in the presence of granulocyte-macrophage colony stimulating factor (GMCSF)-IL4, GMCSF +IL4, lipopolysaccharide (LPS). B 7.1, B7.2 and CD11c were measured by the degree of immune fluorescence using enhanced green fluorescent protein (EGFP) shuttled retrovirus transfected antigen. Degree of MHC class I molecule with antigen presentation of antigen was also evaluated by fluorescence activated cell sorting. The antigen presenting capacity of transfected DCs was investigated. Bone marrow DCs were generated in the presence of GMCSF and IL-4 in vitro. Dividing bone marrow cells were infected with EGFP shuttled retrovirus expressing SSP2 by prolonged centrifugation for three consecutive days from day 5, 6 and 7 and continued to culture in the presence of GMSCF and IL-4 until day 8. Results: IL-4 as a cytokine increased the maturation of retrovirus transfected DCs by high expression of B 7-1 and B 7-2. Also, IL-4 induced DC enhanced by the prolonged centrifugation and it was shown by increased antigen presentation of these dendric cells as antigen presenting cell (APC). Cytolytic effects were significantly higher in cytotoxic T cell response (CTLs) mixed with transfected DCs than CTLs mixed with pulsed DCs. Interpretation & conclusions: There was an enhanced antigen presentation by prolonged expression of antigen loaded MHC class I receptors in DCs in the presence of IL-4 by prolonged centrifugation.

Evaluation of IgG4 and total IgG antibodies against cysticerci and peptide antigens for the diagnosis of human neurocysticercosis by ELISA.

To support the clinical diagnosis of human neurocysticercosis (NCC), we evaluated two peptides, HP6-3 and Ts45W-1, as well as crude saline extract (SE) of Tenia solium cysticerci as antigens for the detection of specific IgG4 subclass and total IgG antibodies by an enzyme-linked immunosorbent assay (ELISA). The sera of definitive diagnosed NCC patients, patients infected with other parasitoses and healthy controls were examined. The diagnostic sensitivity for IgG4 and total IgG detection of the ELISA against SE antigen was 100% and 64.3% with a high amount of cross-reactions to taeniasis saginata at 88.9% (8/9) and 100% (9/9), respectively. The SE-based IgG4-ELISA showed the highest specificity (80.9%). Both peptide-based IgG4-ELISAs provided a superior sensitivity (78.6%) to the total IgG tests whereas their specificity was 66.7% for HP6-3 and 69.8% for Ts45W-1 only. The SE-based ELISA for the detection of specific IgG4 antibody can be used for the diagnosis of neurocysticercosis as well as for serological surveys of NCC endemic areas. The peptide-based IgG4 ELISAs potentially provide a reliable and cost effective alternative method independent from live parasite supply.

The importance of the interaction between leukocyte integrin Mac-1 and platelet glycoprotein Ib-a for leukocyte recruitment by platelets and for the inflammatory response to vascular injury / Importância da interação entre a integrina Mac-1 dos leucócitos e a glicoproteína Iba das plaquetas para o recrutamento de leucócitos pelas plaquetas e para a resposta inflamatória à lesão vascular

OBJETIVO: Avaliar a importância da interação entre a integrina Mac-1 dos leucócitos (a Mb 2) e a glicoproteína (GP) Iba das plaquetas para o recrutamento de leucócitos após a lesão vascular e o efeito da neutralização da interação Mac-1-GPIba sobre a proliferação celular e a hiperplasia neointimal desencadeadas por lesão vascular. MÉTODOS: Um peptídeo denominado M2 ou anticorpo anti-M2 foi desenvolvido para bloquear a interação Mac-1-GPIba . Esse peptídeo foi injetado e comparado com anticorpo-controle em camundongos C57B1/6J submetidos a lesão vascular da artéria femoral com corda-guia. Um, cinco ou 28 dias após a lesão vascular, as artérias femorais foram retiradas para a realização de morfometria e imuno-histoquímica. RESULTADOS: O bloqueio da interação Mac-1-GPIba promoveu uma redução estatisticamente significativa do número de leucócitos na camada média no primeiro dia após a lesão vascular (controle: 7,9±5,0 por cento do total de células versus anti-M2: 2,0±1,6 por cento, p=0,021), bem como determinou uma diminuição estatisticamente significativa do acúmulo de leucócitos na neoíntima em cinco e 28 dias (controle: 42,3±12,9 por cento versus anti-M2: 24,6±10,8 por cento, p=0,047 e controle: 7,9±3,0 por cento versus anti-M2: 3,3±1,3 por cento, p=0,012; respectivamente). A proliferação celular na camada média do vaso em cinco dias pós-lesão foi reduzida com o bloqueio da interação Mac-1-GPIba (controle: 5,0±2,9 por cento do total de células versus anti-M2: 1,8±0,5 por cento; p=0,043), assim como houve diminuição significativa da proliferação celular na camada íntima do vaso em 28 dias (controle: 3,8±1,7 por cento versus anti-M2: 2,0±1,2 por cento; p=0,047). O bloqueio da interação Mac-1-GPIba também determinou uma redução estatisticamente significativa do espessamento intimal em 28 dias pós-lesão (controle: 10.395±3.549 µm² versus anti-M2: 4.561±4.915 ...

OBJECTIVE: To assess the importance of the interaction between leukocyte integrin Mac-1 (a Mb 2) and platelet glycoprotein (GP) Ib-a for leukocyte recruitment after vascular injury and the effect of the neutralization of the Mac-1-GPIba interaction on cell proliferation and the neointimal hyperplasia triggered by the vascular injury. METHODS: A peptide called M2 or anti-M2 antibody was developed to block the Mac-1-GPIba interaction. This peptide was injected and compared to a control-peptide in C57B1/6J mice submitted to vascular injury of the femoral artery with a guide wire. One, five or 28 days after the vascular injury, the femoral arteries were removed for morphometric and immunohistochemical analyses. RESULTS: The blocking of the Mac-1-GPIba interaction promoted a statistically significant reduction in the number of leukocytes in the neointimal layer on the first day after the vascular injury (control: 7.9±5.0 percent of the cell total versus anti-M2: 2.0±1.6 percent, p=0.021), as well as determined a statistically significant decrease in leukocyte accumulation in the neointimal layer on days 5 and 28 (control: 42.3±12.9 percent versus anti-M2: 24.6±10.8 percent, p=0.047 and control: 7.9±3.0 percent versus anti-M2: 3.3±1.3 percent, p=0.012; respectively). Cell proliferation in the neointimal layer of the vessel five days post-injury was reduced with the blocking of the Mac-1-GPIba interaction (control: 5.0±2.9 percent of the cell total versus anti-M2: 1.8±0.5 percent; p=0.043), along with a significant decrease in cell proliferation in the vessel neointimal layer 28 days post-injury (control: 3.8±1.7 percent versus anti-M2: 2.0±1.2 percent; p=0.047). The blocking of the Mac-1-GPIba interaction also determined a statistically significant decrease of the intimal thickening 28 days post-injury (control: 10,395±3,549 µm² versus anti-M2: 4,561±4,915 µm²; ...

Taenia solium metacestode immunodominant peptides recognized by IgG antibodies in cerebrospinal fluid and serum paired samples from patients with active and inactive neurocysticercosis

The aim of this study was to test if serological distinction between patients with active and inactive neurocysticercosis (NCC), could be accomplished by the recognition of immunodominant peptides in total saline antigenic extract of Taenia solium metacestodes by IgG antibody in cerebrospinal fluid (CSF) and serum paired samples. CSF and serum samples of 10 each, active NCC patients, inactive NCC, and individuals with other neurological disorders, were used to recognize the antigenic peptides by western blot (WB). In the active NCC the 28-32 and 39-42 kDa peptides were more frequently detected in CSF than in sera (p < 0.05). The 47-52, 64-68, and 70 kDa antigens showed high frequencies in both samples from patients with active NCC. All the CSF samples of inactive NCC and other neurological disorder (control) patients tested negative, while serum samples from these last two groups recognized mainly the 80, 86, 95, and 98 kDa bands. This finding eliminates the use of the high molecular weigh bands (> 80 kDa) for diagnosis of NCC. The final conclusions were that the difference between active and inactive NCC may be done with the detection of peptides only in the CSF samples and that the 47-52, 64-68, and 70 kDa bands may be included as specific markers for active NCC when detected in CSF samples by WB using total saline extract of T. solium metacestode.

HIV-1 subtyping using gag/env heteroduplex mobility assay and peptide enzyme-linked immunosorbent assay.

Two HIV-1 subtypes have accounted for virtually all infections in Thailand: subtype B', found mainly in injection drug users (IDUs), and CRF01_AE (initially subtype E), found in over 90% of sexually infected persons and increasingly in IDUs in recent years. During 1997-1998, 227 blood samples were collected from HIV-1 infected individuals consisting of 92 mothers, 35 children and 100 IDUs. The blood samples were subtyped by heteroduplex mobility assay (HMA) and peptide enzyme-linked immunosorbent assay (PEIA). Using gag and env HMA, CRF01_AE and subtype B' accounted for 96-97% and 3-4% of both the mothers and the children, respectively. In the IDU group, 10% of the plasma samples could only be performed by gag HMA and gave the result as CRF01_AE. CRF01_AE and subtype B' using PEIA accounted for 67% and 33% of the IDUs. There was 100% concordance of the results between gag HMA and env HMA. Ninety-five percentages of concordant results were observed between HMA and PEIA. Of the 6/134 (5%) subjects with discordant results, nucleotide sequencing, used as a gold standard, confirmed the HMA result. In this study, HIV-1 was successfully genotyped by HMA and PEIA. However, a comparison of the subtyping results between HMA and PEIA revealed that HMA was slightly more accurate than PEIA.

Preparation and characterization of polyclonal antibodies against VLDL receptor / 华中科技大学学报（医学）（英德文版）

The polyclonal antibodies against VLDL receptor were prepared and identified. Rabbits were immunized with polypeptide fragment of VLDL receptor as antigen. The collected blood serum of the immunized rabbits was analyzed and identified by using ELISA and Western Blot. The results showed that the rabbit against mouse and human VLDL receptor antibodies were obtained with high titer and could recognize the natural VLDL receptors through Western blot. The prepared polyclonal antibodies against VLDL receptor provide a new tool to study the protein of VLDL receptor.

A role for extracellular amastigotes in the immunopathology of Chagas disease

In spite of the growing knowledge obtained about immune control of Trypanosoma cruzi infection, the mechanisms responsible for the variable clinico-pathological expression of Chagas disease remain unknown. In a twist from previous concepts, recent studies indicated that tissue parasitism is a pre-requisite for the development of chronic myocarditis. This fundamental concept, together with the realization that T. cruzi organisms consist of genetically heterogeneous clones, offers a new framework for studies of molecular pathogenesis. In the present article, we will discuss in general terms the possible implications of genetic variability of T. cruzi antigens and proteases to immunopathology. Peptide epitopes from a highly polymorphic subfamily of trans-sialidase (TS) antigens were recently identified as targets of killer T cell (CTL) responses, both in mice and humans. While some class I MHC restricted CTL recognize epitopes derived from amastigote-specific TS-related antigens (TSRA), others are targeted to peptide epitopes originating from trypomastigote-specific TSRA. A mechanistic hypothesis is proposed to explain how the functional activity and specificity of class I MHC restricted killer T cells may control the extent to which tissue are exposed to prematurely released amastigotes. Chronic immunopathology may be exacerbated due the progressive accumulation of amastigote-derived antigens and pro-inflammatory molecules (eg. GPI-mucins and kinin-releasing proteases) in dead macrophage bodies.

Liposomes: from biophysics to the design of peptide vaccines

Liposomes (lipid-based vesicles) have been widely studied as drug delivery systems due to their relative safety, their structural versatility concerning size, composition and bilayer fluidity, and their ability to incorporate almost any molecule regardless of its structure. Liposomes are successful in inducing potent in vivo immunity to incorporated antigens and are now being employed in numerous immunization procedures. This is a brief overview of the structural, biophysical and pharmacological properties of liposomes and of the current strategies in the design of liposomes as vaccine delivery systems

Diagnostico serologico de la enfermedad celiaca: anticuerpos anti-pepticos de sintesis de gliadina y anti-transglutaminasa de tejido / Serological diagnosis of disease: anti-gliadin peptide antitibodies and tissue anti-transglutaminase

Los marcadores serológicos comúnmente utilizados en el diagnóstico de la enfermedad celíaca son los anticuerpos antigliadina (AG) y antiendomisio (AE). Recientemente (1997) se identificó a la transglutaminasa de tejido (tTG) como el principal autoantígeno de los anticuerpos AE. El objetivo de este trabajo fue determinar la sensibilidad y especificidad de testes de ELISA desarrollados en base a la utilización de estructuras moleculares definidas como antígenos de captura para los anticuerpos AG y AE. Como antígenos inmovilizados para los anticuerpos AG se ensayaron tres péptidos de sínteses correspondientes a la región amino terminal de la alfa gliadina y para los AE, la transglutaminasa de hígado de cobayo. Se examinaron un total de 80 sueros correspondientes a: pacientes celíacos, no tratados y tratados, controles enfermos no celíacos y controles sanos. Rango de edad: 7 meses a 14 años. Se obtuvo una sensibilidad del 97 por ciento y una especificidad 86 por ciento para la IgG determinada utilizando como antígeno uno de los tres péptidos de síntesis (correspondiente a los residuos 31-55 de la alfa gliadina). Este péptido aparece como un antígeno altamente sensible y más específico que la gliadina. El mejor resultado, con un 100 por ciento de especificidad y sensibilidad, se obtuvo en la determinación de la IgA anti-tTG, lo que destaca la relevancia de estos anticuerpos como marcadores serológicos de la enfermedad celíaca.