ABSTRACT
Genetic variations in components of the immune response seem to be an important factor that contributes to the manifestation of symptoms of some diseases related to HTLV-1 infection. Nerve growth factor (NGF) and the p75 neurotrophin receptor (p75NTR) are related to the maintenance of neurons and the activation of the immune response. In this study, we evaluated the association of the NGF -198C/T, NGF Ala35Val, and p75NTR Ser205Leu polymorphisms with HTLV-1 infection and plasma cytokine levels in 166 samples from individuals infected with HTLV-1 (59 symptomatic and 107 asymptomatic). The genotyping and quantification of the proviral load were performed by real-time PCR, and cytokine levels were measured by ELISA. The NGF -198C/T and NGF Ala35Val polymorphisms were not associated with HTLV-1 infection. The frequency of the Ser/Leu genotype of p75NTR Ser205Leu was more frequent in the control group (p = 0.0385), and the Ser/Leu genotype and allele Leu were more frequent among the asymptomatic (p < 0.05), especially with respect to the HTLV-1-associated myelopathy (HAM) group (p < 0.05). The symptomatic showed a higher proviral load and higher TNF-α and IL-10 levels (p < 0.05). Asymptomatic carriers of the Ser/Leu genotype (p = 0.0797) had lower levels of proviral load and higher levels of TNF-α (p = 0.0507). Based on the results obtained, we conclude that the p75NTR Ser205Leu polymorphism may be associated with reduced susceptibility to HTLV-1 infection, a lower risk of developing symptoms, including HAM, and better infection control.
Subject(s)
HTLV-I Infections , Human T-lymphotropic virus 1 , Paraparesis, Tropical Spastic , Cytokines , Human T-lymphotropic virus 1/genetics , Humans , Nerve Growth Factor , Proviruses/genetics , Receptor, Nerve Growth Factor , Tumor Necrosis Factor-alpha , Viral LoadABSTRACT
Human T-lymphotropic virus type 1 (HTLV-1) deregulates the immune system and cell cycle, resulting in loss of immune tolerance and disease, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Three prime repair exonuclease 1 (TREX1) maintains innate immune tolerance of the host and host-cell permissiveness to retroviral infections. TREX1 polymorphisms may influence the course of infection and autoimmune manifestations. The influence of TREX1 531C/T polymorphism was investigated in HTLV-1 infection and development of symptoms among 151 persons infected with HTLV-1 (32 HAM/TSP, 19 rheumatologic manifestations, two dermatitis, five more than one diagnosis, two probable HAM/TSP, and 91 asymptomatic individuals) and 100 uninfected persons in the control group. Polymorphism genotyping and proviral load quantification were performed by real-time polymerase chain reaction (PCR) and antinuclear antibodies (ANAs) were screened by an indirect immunofluorescence assay. No statistically significant difference was found in polymorphism genotype and allele frequencies between the infected and control groups. HAM/TSP patients showed higher frequency of TT genotype than asymptomatic persons (p = 0.0339). Proviral load was significantly higher among individuals with CT/TT genotypes and CC genotype carriers had lower proviral load and higher levels of proinflammatory cytokines. ANAs were present only in the HAM/TSP group. TREX1 531C>T polymorphism seems to be associated with TREX-1 regulation and HTLV-1 infection.
Subject(s)
Exodeoxyribonucleases/genetics , Genetic Predisposition to Disease , HTLV-I Infections/genetics , HTLV-I Infections/virology , Human T-lymphotropic virus 1/physiology , Phosphoproteins/genetics , Polymorphism, Single Nucleotide , Viral Load , Alleles , Female , Gene Frequency , Genetic Association Studies , Genotype , Host-Pathogen Interactions/genetics , Humans , MaleABSTRACT
Foi realizado um estudo comparativo da reaçäo de imunofulorescência em eluatos de sangue de cäes infectados experimentalmente com diferentes tripanosomatídeos. Utilizaram-se como antígeno promastigotas de L. mexicana, L. braziliensis e L chagasi. Os resultados mostraram que a sensibilidade do método foi de 87,5%para o diagnóstico do calazr canino, independentemente do antígeno empregado; e que ocorre reaçäo cruzada com Leishmaniose tegumentar em 75%dos casos e com doença de Chagas em 83,3%. Levantamento epidemiológico em área de leishmaniose confirma que a reaçäo de imunofluorescência em eluatos de sangue canino fornece reaçöes cruzadas em cäes infectados com Leishmania brasiliensis e L. chagasi. Näo se verificou reaçäo cruzada pela RFC. Sugere-se a utilizaçäo da reaçäo de imunofluorescência nas campanhas de saúde pública mas é de se chamar a atençäo para o fato de que as taxas de positividade näo devem ser utilizadas como indicadores da prevalência do calazar canino
Subject(s)
Dog Diseases/blood , Leishmaniasis, Visceral/blood , Leishmaniasis, Visceral/veterinary , Dog Diseases/epidemiology , Epidemiologic Methods , Evaluation Study , Fluorescent Antibody Technique , Leishmaniasis, Visceral/epidemiologyABSTRACT
A influência da infecçäo esquistossomótica no desenvolvimento da leishmaniose por Leishmania mexicana amazonensis foi estudada tendo o camundongo como modelo experimental. Os animais foram infectados com a cepa LE de Schistosoma mansoni 45 dias antes da infecçäo leishmaniótica (105 promastigotas de cultura recentemente isolada de hamsters infectados). Os animais controle receberam apenas a infecçäo pelo protozoário. Verificou-se uma significativa diminuiçäo do período de incubaçäo das lesöes leishmanióticas no grupo de animais com esquistossomose prévia e, neste caso, tais lesöes também eram significativamente maiores que as observadas no grupo controle.
