RESUMO
Las larvas musculares (LM) de T. spiralis alteran la agregación eritrocitaria. El objetivo del trabajo fue estudiar la cinética de desialización eritrocitaria producida por LM vivas de T. spiralis. Se realizaron 3 experiencias en las que se incubaron 60 larvas con 30 μL de eritrocitos en 1 mL de solución salina durante 1, 2, 3, 4, 5, 6, 7, 10, 15, 18, 20, 22 y 24 horas. Se aplicó el Método de Titulación de la Agregación por Polibrene y se calculó Título, Score Total y CexpCASP en los eritrocitos Control e incubados con LM. Los resultados mostraron que en la primera hora no hubo captación de ácido siálico. A las 2 horas el coeficiente comenzó a decrecer y a las 3 horas el Título disminuyó en una dilución y el coeficiente fue 0,62±0,021. En los siguientes tiempos el Título se mantuvo y el valor del coeficiente presentó pequeñas disminuciones, hasta alcanzar el valor de 0,45±0,010 a las 22 horas, tiempo en que se produjo la disminución significativa del Título. A las 24 horas hubo una nueva disminución del Título del Control y CexpCASP fue 0,13±0,093. Se concluye que las LM vivas durante incubación in vitro con eritrocitos comenzarían a captar ácido siálico a partir de las 2 horas de contacto logrando la desialización casi completa del eritrocito a las 24 horas.
T. spiralis muscle larvae (ML) alter erythrocyte aggregation. The objective of this work was to study erythrocyte desialylation kinetics produced by living T. spiralis ML. Three experiments were conducted in which 60 larvae were incubated with 30 μL of erythrocytes in 1 mL of saline solution for 1, 2, 3, 4, 5, 6, 7, 10, 15, 18, 20, 22 and 24 hours. Titration of Aggregation by Polybrene Method was used and Title, Total Score and CexpCASP were calculated in Control erythrocytes and erythrocytes incubated with ML. The results showed that in the first hour there was no capture of sialic acid. The coefficient began to decrease at 2 hours, and at 3 hours the Title decreased in one dilution and the coefficient was 0.62±0.021. The title was maintained at the following times and the coefficient value presented small decreases, until reaching 0.45±0.010 value at 22 hours. It was then that, a significant decrease in Title occurred. Within 24 hours, there was a further decrease of Control Title, and CexpCASP was 0.13±0.093. It can be concluded that living ML during in vitro incubation with erythrocytes began to capture sialic acid after 2 hours of contact, getting almost complete desialylation of erythrocytes at 24 hours.
As larvas musculares (LM) de T. spiralis alteram a agregação eritrocitaria. O objetivo do trabalho foi estudar a cinética de dessialização eritrocitária produzida por LM vivas de T. spiralis. Realizaram-se 3 experiências nas quais foram incubadas 60 larvas com 30 μL de eritrócitos em 1 μL de solução salina durante 1, 2, 3, 4, 5, 6, 7, 10, 15, 18, 20, 22 y 24 horas. Foi aplicado o Método de Titulação da Agregação por Polibreno e se calculou Título, Pontuação Total (ST) e CexpCASP. Os resultados mostraram que na primeira hora não houve captura de acido siálico. Às 2 horas o coeficiente começou a decrescer e às 3 horas o Título diminuiu numa diluição e o coeficiente foi 0,62±0,021. Nos tempos seguintes o Título se manteve e o valor do coeficiente apresentou pequenas diminuições, até atingir o valor de 0,45±0,010 às 22 horas, tempo em que se produziu a diminuição significativa do Título. Às 24 horas houve uma nova diminuição do Título do Controle e o CexpCASP foi 0,13±0,093. Conclui-se que as LM vivas durante incubação in vitro com eritrócitos, começariam a captar ácido siálico a partir das 2 horas de contato conseguindo a dessialização quase completa do eritrócito às 24 horas.
Assuntos
Animais , Trichinella spiralis/microbiologia , Eritrócitos/virologia , Cinética , Trichinella spiralis , LarvaRESUMO
Triatoma virus is the only virus whose genome has been sequenced and studied in triatomines. It belongs to the family Dicistroviridae. In order to detect whether TrV has the ability to agglutinate erythrocytes of domestic and laboratory animals, we performed a hemagglutination assay. Positive hemagglutination was found for red blood cells of guinea pigs. The HA assay could be used as a titration method, at least for purified viral particles obtained from triatomine stool. This is the first record of hemagglutinating properties for Dicistroviridae.
Assuntos
Dicistroviridae/fisiologia , Eritrócitos/virologia , Hemaglutinação , Animais , CobaiasRESUMO
BACKGROUND: Aedes aegypti is the main vector of dengue, a disease that is increasing its geographical range as well as incidence rates. Despite its public health importance, the effect of dengue virus (DENV) on some mosquito traits remains unknown. Here, we investigated the impact of DENV-2 infection on the feeding behavior, survival, oviposition success and fecundity of Ae. aegypti females. METHODS/PRINCIPAL FINDINGS: After orally-challenging Ae. aegypti females with a DENV-2 strain using a membrane feeder, we monitored the feeding behavior, survival, oviposition success and fecundity throughout the mosquito lifespan. We observed an age-dependent cost of DENV infection on mosquito feeding behavior and fecundity. Infected individuals took more time to ingest blood from anesthetized mice in the 2(nd) and 3(rd) weeks post-infection, and also longer overall blood-feeding times in the 3(rd) week post-infection, when females were around 20 days old. Often, infected Ae. aegypti females did not lay eggs and when they were laid, smaller number of eggs were laid compared to uninfected controls. A reduction in the number of eggs laid per female was evident starting on the 3(rd) week post-infection. DENV-2 negatively affected mosquito lifespan, since overall the longevity of infected females was halved compared to that of the uninfected control group. CONCLUSIONS: The DENV-2 strain tested significantly affected Ae. aegypti traits directly correlated with vectorial capacity or mosquito population density, such as feeding behavior, survival, fecundity and oviposition success. Infected mosquitoes spent more time ingesting blood, had reduced lifespan, laid eggs less frequently, and when they did lay eggs, the clutches were smaller than uninfected mosquitoes.
Assuntos
Aedes/virologia , Vírus da Dengue , Fertilidade , Oviposição , Fatores Etários , Animais , Comportamento Animal , Dengue/transmissão , Eritrócitos/virologia , Comportamento Alimentar , Feminino , Insetos Vetores , Camundongos , CoelhosRESUMO
Bovine anaplasmosis is a hemoparasitic disease that causes considerable economic loss to the dairy and beef industries. Cattle immunized with the Anaplasma marginale MSP1 outer membrane protein complex presents a protective humoral immune response; however, its efficacy is variable. Immunodominant epitopes seem to be a key-limiting factor for the adaptive immunity. We have successfully demonstrated that critical motifs of the MSP1a functional epitope are essential for antibody recognition of infected animal sera, but its protective immunity is yet to be tested. We have evaluated two synthetic vaccine formulations against A. marginale, using epitope-based approach in mice. Mice infection with bovine anaplasmosis was demonstrated by qPCR analysis of erythrocytes after 15-day exposure. A proof-of-concept was obtained in this murine model, in which peptides conjugated to bovine serum albumin were used for immunization in three 15-day intervals by intraperitoneal injections before challenging with live bacteria. Blood samples were analyzed for the presence of specific IgG2a and IgG1 antibodies, as well as for the rickettsemia analysis. A panel containing the cytokines' transcriptional profile for innate and adaptive immune responses was carried out through qPCR. Immunized BALB/c mice challenged with A. marginale presented stable body weight, reduced number of infected erythrocytes, and no mortality; and among control groups mortality rates ranged from 15% to 29%. Additionally, vaccines have significantly induced higher IgG2a than IgG1 response, followed by increased expression of pro-inflammatory cytokines. This is a successful demonstration of epitope-based vaccines, and protection against anaplasmosis may be associated with elicitation of effector functions of humoral and cellular immune responses in murine model.
Assuntos
Anaplasma marginale/imunologia , Anaplasmose/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Epitopos/imunologia , Imunidade Celular , Imunidade Humoral , Motivos de Aminoácidos/imunologia , Anaplasmose/prevenção & controle , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Proteínas da Membrana Bacteriana Externa/química , Bovinos , Citocinas/genética , Citocinas/imunologia , Modelos Animais de Doenças , Epitopos/genética , Eritrócitos/imunologia , Eritrócitos/virologia , Feminino , Imunização , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Mediadores da Inflamação/imunologia , Camundongos , Peptídeos/síntese química , Peptídeos/imunologia , Baço/citologia , Baço/imunologia , Transcrição GênicaRESUMO
BACKGROUND: HIV binding has been demonstrated in erythrocytes from HIV-positive and HIV-negative individuals. However, the presence of immunoglobulins G anti-HIV (IgG anti-HIV) in erythrocytes from HIV-positive individuals is still to be elucidated. Moreover, the capacity of erythrocytes from HIV-positive individuals to capture an additional amount of HIV has not been studied. Indeed, it is unknown if HIV binding to erythrocytes in HIV-positive persons could have consequences on the cell-free infectious virus available. METHODOLOGY/PRINCIPAL FINDINGS: IgGs anti-HIV associated to erythrocytes were found in 77.3% (58/75) of the HIV-positive individuals studied and the IgGs anti-gp160 and anti-p24 were the most frequently found. We found a positive association between detectable plasma viral load (pVL) and presence of IgGs anti-HIV associated to erythrocyte (p<0.005), though the anti-p24/160 were present with or without detectable pVL. The HIV capture capacity was higher in erythrocytes from HIV-positive than HIV-negative individuals (p<0.0001). Furthermore, among the HIV-positive individuals the higher viral capture capacity was associated with the presence of anti-gp160/gp120 on erythrocytes. Moreover, the viral capture by erythrocytes was independent of pVL (rho=0.022, p=0.8817). Additionally, reduction of cell-free infectious virus and available viral load was observed in the presence of erythrocytes from HIV-positive individuals. CONCLUSIONS/SIGNIFICANCE: Results suggest that in HIV-positive individuals, erythrocytes are capable of capturing high amounts of HIV by the presence of IgGs anti-gp160/120 on their membranes and this may produce a reduction in the available free virus. Finally, the current measurement of pVL would underestimate the real viral quantity due to the HIV binding through specific antibodies to erythrocytes.
Assuntos
Eritrócitos/virologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp160 do Envelope de HIV/metabolismo , Infecções por HIV/imunologia , Imunoglobulina G/imunologia , Adulto , Idoso , Estudos de Casos e Controles , Linhagem Celular Tumoral , Proteínas do Sistema Complemento , Eritrócitos/citologia , Infecções por HIV/metabolismo , Soropositividade para HIV , Humanos , Imunoglobulina G/química , Pessoa de Meia-Idade , Modelos Estatísticos , Carga ViralRESUMO
Rhabdoviruses infect a variety of hosts, including non-avian reptiles. Consensus PCR techniques were used to obtain partial RNA-dependent RNA polymerase gene sequence from five rhabdoviruses of South American lizards; Marco, Chaco, Timbo, Sena Madureira, and a rhabdovirus from a caiman lizard (Dracaena guianensis). The caiman lizard rhabdovirus formed inclusions in erythrocytes, which may be a route for infecting hematophagous insects. This is the first information on behavior of a rhabdovirus in squamates. We also obtained sequence from two rhabdoviruses of Australian lizards, confirming previous Charleville virus sequence and finding that, unlike a previous sequence report but in agreement with serologic reports, Almpiwar virus is clearly distinct from Charleville virus. Bayesian and maximum likelihood phylogenetic analysis revealed that most known rhabdoviruses of squamates cluster in the Almpiwar subgroup. The exception is Marco virus, which is found in the Hart Park group.
Assuntos
Répteis/virologia , Infecções por Rhabdoviridae/virologia , Rhabdoviridae/genética , Animais , Austrália , Eritrócitos/virologia , Lagartos/virologia , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Rhabdoviridae/classificação , Rhabdoviridae/isolamento & purificação , Rhabdoviridae/ultraestrutura , Infecções por Rhabdoviridae/patologia , América do SulRESUMO
BACKGROUND: HIV adherence to erythrocytes has been demonstrated in vitro, and it has been suggested that erythrocytes may be carriers of the virus. However, the association between HIV particles or viral proteins and erythrocytes in HIV-infected individuals is still to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: HIV-positive participants (n =112) were classified into two groups according to values of three plasma viral loads (pVL) determined during the 12-month period prior to the study. The first group included 71 individuals with detectable pVL, whereas the second group included 41 individuals with undetectable pVL. Plasma viral load, erythrocyte-associated p24-antigen and p24-antigen in plasma were determined at the moment of the study. A total of 51 out of the 71 patients with detectable pVL showed erythrocyte-associated p24-antigen whereas 13 showed p24-antigen in plasma. Twenty-two out of the 51 patients with erythrocyte-associated p24-antigen showed pVL<10,000 copies/ml and undetectable p24-antigen in plasma. The data indicates that the amount of erythrocyte-associated p24-antigen was not related to p24-antigen in plasma or pVL levels in this group. Among the 41 patients with prior undetectable pVL, eight presented detectable pVL and erythrocyte-associated p24-antigen at the moment of the study. The other 33 showed undetectable pVL and five of these presented erythrocyte-associated p24-antigen. A positive relationship was found between the presence of erythrocyte-associated p24-antigen and the detectable pVL at the moment of the study (p<0.00001). Even more, in another series of assays, a detectable viral load associated to erythrocytes was determined and it was always accompanied by erythrocyte-associated p24-antigen detection. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the presence of erythrocyte-associated p24-antigen in HIV-infected individuals. Since erythrocyte-associated p24-antigen is not always related to pVL or p24-antigen in plasma, erythrocyte-associated p24-antigen showed viral expression not represented in plasma. Therefore, the determination of erythrocyte-associated p24-antigen may contribute to better understand the kinetics and/or evolution of HIV infection.
Assuntos
Eritrócitos/virologia , Proteína do Núcleo p24 do HIV/metabolismo , Infecções por HIV/sangue , Carga Viral , Antígenos Virais , Proteína do Núcleo p24 do HIV/sangue , Infecções por HIV/virologia , Soropositividade para HIV , HumanosRESUMO
BACKGROUND: WBC depletion by filtration may prevent the transmission of HTLV-I, which requires cell-to-cell contact. The removal of HTLV-I-infected cells in routinely filtered blood cell components was measured. STUDY DESIGN AND METHODS: The study was conducted in Martinique where systematic screening for HTLV-I and -II and universal leukoreduction are mandatory. HTLV-I was quantified by use of real-time PCR in 8 RBC units and 4 PLT concentrates before and after filtration. HTLV-I proviral load in PBMNCs was determined in five of the eight HTLV-I-infected blood donors. RESULTS: The amount of MNC-associated HTLV-I DNA in RBC units before filtration was 21 x 10(6)+/- 29 x 10(6) copies (mean +/- SD). HTLV-I was detected in 4 of 8 RBC units after filtration, with a number of copies in the MNC fraction ranging from 20 to 140, following a 4.9 to 5.8 log reduction. Flow cytometry analysis performed in 2 of the filtered RBC units containing detectable HTLV-I showed suboptimal and out-of-range leukoreduction (0.56 x 10(6) and 1.22 x 10(6) residual WBCs). HTLV was not detected in filtered RBCs from the blood donor with the highest percentage of HTLV-I-infected PBMCs (9%). CONCLUSION: This study confirms that HTLV-I-infected cells can be detected in filtered blood cell components and shows that optimal leukoreduction is critical for HTLV-I removal.
Assuntos
Células Sanguíneas/virologia , Doadores de Sangue , Infecções por Deltaretrovirus/virologia , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Leucaférese , Carga Viral , Plaquetas/virologia , Sistemas Computacionais , DNA Viral/análise , Infecções por Deltaretrovirus/sangue , Eritrócitos/virologia , Filtração , Citometria de Fluxo , Vírus Linfotrópico T Tipo 1 Humano/genética , Humanos , Monócitos/virologia , Reação em Cadeia da Polimerase , Controle de Qualidade , Sensibilidade e EspecificidadeRESUMO
Blood erythrocytes of Brazilian tree-frogs, Phrynohyas venulosa were found to frequently contain single, small, densely staining inclusions. Electron microscopy showed these to be icosahedral viral particles which measured from 250-280 nm in diameter: they were devoid of an envelope, and thus differed from previously described viruses of frog erythrocytes. The infected erythrocytes lacked a crystalline body.