RESUMO
We report the first study on prevalence of antiretroviral drug-associated resistance mutations in Venezuela. Protease and reverse transcriptase (RT) coding regions were analyzed in DNA samples obtained from 100 HIV-1-infected individuals. Primary resistance mutations to RT inhibitors were identified in 26% of patients treated with these drugs. Transmission of HIV-1-resistant strains was detected in a drug-naive patient (3%). Primary resistance mutations to protease inhibitors (PIs) were present in 9% of the 44 PI-treated patients and in 1 PI-naive individual. Phylogenetic analysis of these samples has resulted in the most extensive survey, to date, of HIV-1 genetic forms circulating in Venezuela. Ninety-nine samples clustered with subtype B, and 1 individual harbored the first B/F recombinant virus reported in Venezuela, with protease clustering with subtype F and RT with subtype B. In addition, this isolate had a new insertion (Glu-34 duplication) in the protease gene.
Assuntos
Infecções por HIV/virologia , Protease de HIV/genética , Transcriptase Reversa do HIV/genética , HIV-1/genética , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Resistência Microbiana a Medicamentos , Quimioterapia Combinada , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , HIV-1/efeitos dos fármacos , Humanos , Masculino , Dados de Sequência Molecular , Mutação , Filogenia , Inibidores de Proteases/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Venezuela/epidemiologiaRESUMO
A polyclonal CD3(+), CD8(+) T-cell line, G2, was derived from the peripheral blood of a seropositive, PCR-positive, HTLV-IIB infected Guahibo Indian from Venezuela. The cell line is productively infected with HTLV-IIB. The entire HTLV-II G2 proviral DNA was sequenced via PCR using overlapping HTLV-II primer pairs. Phylogenetic analyses indicate that HTLV-II G2 is the most divergent HTLV-IIB strain identified to date. Characterization of its deduced proteins and its relationship to other members of the PTLV/BLV genus of retroviruses are discussed.
Assuntos
Genoma Viral , Vírus Linfotrópico T Tipo 2 Humano/genética , Indígenas Sul-Americanos , Sequência de Aminoácidos , Células Cultivadas , DNA Viral/análise , Vírus Linfotrópico T Tipo 2 Humano/classificação , Vírus Linfotrópico T Tipo 2 Humano/isolamento & purificação , Humanos , Imunofenotipagem , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , VenezuelaRESUMO
The peripheral blood of 41 Yaruro and Guahibo Indians from Venezuela was examined for HTLV antibodies and DNA. Twenty-five samples (61%) were found to be infected with HTLV-IIB. The sensitivities of the serologic and DNA polymerase chain reaction (PCR) analyses were 80% and 96%, respectively. Epidemiologic studies supported both sexual and perinatal transmission of the virus. Sequence analyses of the HTLV-IIB strains from these Indians indicate that they are unique relative to HTLV-II detected in other groups of humans. HTLV-IIB-G2 isolated from a Guahibo Indian is the most divergent HTLV-IIB strain relative to the prototype HTLV-II NRA.
Assuntos
Infecções por HTLV-II/etnologia , Vírus Linfotrópico T Tipo 2 Humano/genética , Indígenas Sul-Americanos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Cricetinae , Transmissão de Doença Infecciosa , Infecções por HTLV-II/genética , Infecções por HTLV-II/transmissão , Vírus Linfotrópico T Tipo 2 Humano/classificação , Humanos , Transmissão Vertical de Doenças Infecciosas , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Homologia de Sequência do Ácido Nucleico , Estudos Soroepidemiológicos , Venezuela/epidemiologiaRESUMO
Sera from 166 Guahibo Indians (55% of the population) living in southwest Venezuela were screened by enzyme-linked immunoassay for antibodies to human T-cell lymphotropic virus (HTLV) I and II. Positive samples were confirmed by immunofluorescence and Western blot. Forty-one Guahibos (24.8%) were found to be seropositive. Polymerase chain reaction (PCR) analysis of proviral DNA in mononuclear cell lysates revealed the virus to be HTLV-II. Prevalence increased with age, and sexual contact with HTLV-II-seropositive partners was identified as a risk factor for infection. PCR amplification of a region of the pol gene, utilizing the primer pair SK110/SK111, with subsequent digestion of the 140-base-pair amplification products with HinfI and MseI restriction enzymes, showed an HTLV-II subtype-b restriction pattern in all cases. These data suggest that the substrain infecting this Guahibo community belongs to the b subtype, the most frequent among Paleo-Amerindian populations.
Assuntos
Infecções por HTLV-II/epidemiologia , Vírus Linfotrópico T Tipo 2 Humano/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Idoso , Western Blotting , Criança , Pré-Escolar , DNA Viral/análise , Feminino , Genes pol , Infecções por HTLV-II/genética , Infecções por HTLV-II/imunologia , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Vírus Linfotrópico T Tipo 2 Humano/genética , Vírus Linfotrópico T Tipo 2 Humano/imunologia , Humanos , Indígenas Sul-Americanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos , Comportamento Sexual , Venezuela/epidemiologiaRESUMO
We describe for the first time the presence of human T lymphotropic virus type II (HTLV-II) infection in Venezuela, among the Pume Amerindians living in the southern plains of the country. Antibodies to HTLV-II antigens were assessed by enzyme immunoassays (Elisa), Western blot, radioimmuno-precipitation, and immunofluorescence; titration studies against HTLV-I- and HTLV-II-infected cell lines were very useful in the differentiation of HTLV-I and HTLV-II antibodies. The HTLV-II general prevalence was 5%; however, there is a striking difference in prevalence between the truly isolated villages (0%) when compared to those living along the riverside and thus in contact with outsiders (9%). Preliminary evidence suggests sexual contact as the main source of transmission. These findings might suggest that HTLV-II in Venezuela originated through contact with outsiders rather than ancient infection related to the origins of the Pume.
Assuntos
Infecções por HTLV-II/etnologia , Indígenas Sul-Americanos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Imunofluorescência , Anticorpos Anti-HTLV-I/sangue , Anticorpos Anti-HTLV-II/sangue , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , Ensaio de Radioimunoprecipitação , Venezuela/epidemiologiaRESUMO
A group of Venezuelan patients with SLE showed an increased proportion of responders to Leu-4, an anti-CD3 MoAb of the IgG1 class, compared with ethnically matched non-SLE patients and healthy controls. The rate of proliferative responses or IL-2 production induced by MoAb Leu-4, and the helper effect of macrophages from Leu-4 responders on T cells from a third-party donor were comparable in patients and controls. No significant differences in the binding of murine IgG1 molecules by macrophages from SLE patients and controls were observed. The proportion of monocytes/macrophages expressing Fc gamma RI was significantly higher in SLE patients. However, the expression of FcRII, the type capable of supporting Leu-4-mediated responses, and of Fc gamma RIII was comparable in monocytes from SLE patients and controls. Our results suggest that Venezuelan patients with SLE may have a genetic predisposition for the expression of the phenotypic variant of Fc gamma RII capable of binding murine IgG1 molecules.
Assuntos
Anticorpos Monoclonais/imunologia , Complexo CD3/imunologia , Imunoglobulina G/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Adolescente , Adulto , Animais , Feminino , Humanos , Imunoglobulina G/classificação , Interleucina-2/biossíntese , Ativação Linfocitária , Macrófagos/imunologia , Masculino , Camundongos , Monócitos/imunologia , Receptores Fc/biossíntese , Receptores de IgG/imunologia , Linfócitos T/imunologiaRESUMO
Natural killer (NK) cytotoxic activity was simultaneously investigated in bone marrow mononuclear cells (BMMC) and peripheral blood lymphocytes (PBL) from nine Hodgkin's disease (HD) and 15 non-Hodgkin lymphoma (NHL) untreated patients. Twenty-five PBL samples and seven bone marrow specimens from healthy individuals were also included as control group (C). NK cell activity was evaluated in basal condition and post-stimulation with human recombinant IL-2 (rIL-2). Data were expressed in K values (number of BMMC or PBL needed to lyse 50% of the target cells). In basal condition, both HD and NHL patients showed a NK cell activity comparable to the C group, both in BMMC (HD, K = 2.48 +/- 1.3; NHL, K = 3.8 +/- 2.0; C, K = 3.2 +/- 0.7) and PBL (HD, K = 2.0 +/- 1.0; NHL, K = 2.3 +/- 1.0; C, K = 2.2 +/- 0.2). Stimulation with rIL-2 induced a significant and comparable enhancement of the NK activity in PBL from HD, NHL and C while the response to rIL-2 of the BMMC in most of the HD and NHL patients was significantly greater than the C group. Responder cells were characterized by negative selection with specific MoAb plus complement as a CD3-, CD16+, CD56+ cytotoxic cell and further confirmed by flow cytometry. We postulate that IL-2 activation of bone marrow NK cell precursors, in addition to enhancing the activity of circulating NK, may be of value for the therapeutic rationale of IL-2 in patients with lymphoma.
Assuntos
Medula Óssea/imunologia , Interleucina-2/farmacologia , Células Matadoras Naturais/imunologia , Linfoma/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos T/fisiologia , Complexo CD3 , Antígeno CD56 , Criança , Citotoxicidade Imunológica , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/fisiologia , Proteínas Recombinantes/farmacologiaRESUMO
Nonfractionated peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed enhanced proliferative responses when stimulated via the CD3 pathway. In contrast, proliferative responses induced by phytohemagglutinin were diminished in SLE patients. Levels of CD3-induced interleukin-2 production and interleukin-2 receptor expression were comparable with normal levels. Highly purified T cells also showed augmented CD3 responses, but only in the presence of phorbol myristate acetate or a combination of phorbol myristate acetate plus calcium ionophore A23187, and not with calcium ionophore alone. The data suggest integrity of the T cell receptor/CD3 pathway for T cell activation in patients with SLE, as examined in cultures stimulated with specific anti-CD3 monoclonal antibodies rather than with multivalent lectins. An increased response via the CD3 complex could contribute to the autoimmune activity in human SLE.
Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Ativação Linfocitária , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/imunologia , Adolescente , Adulto , Anticorpos Monoclonais/farmacologia , Complexo CD3 , Divisão Celular , Humanos , Interleucina-2/biossíntese , Lúpus Eritematoso Sistêmico/metabolismo , Muromonab-CD3 , Receptores de Interleucina-2/metabolismo , Linfócitos T/metabolismo , Linfócitos T/patologiaRESUMO
This study examined the role of human recombinant interferon-gamma (rIFN-gamma) in the expression of interleukin-2 receptors (IL-2R) by human T lymphocytes. rIFN-gamma enhanced total numbers of IL-2R in mitogen-activated but not resting T cells. Scatchard plot analysis indicated that rIFN-gamma increased both high- and low-affinity receptors, with a predominant effect on the latter. Phytohaemagglutinin (PHA)-activated T cells treated with IFN-gamma showed higher IL-2 binding and greater IL-2 internalization and degradation than cells treated with PHA alone. There was a corresponding increase of mitogen-driven proliferative responses, indicating an increase of functional receptors in IFN-treated cultures. IFN-gamma may influence T-cell activation and proliferation by enhancing expression of IL-2R and promoting IL-2 uptake by mitogen-activated lymphocytes.
Assuntos
Interferon gama/farmacologia , Ativação Linfocitária , Receptores de Interleucina-2/metabolismo , Linfócitos T/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Células Cultivadas , Humanos , Interleucina-2/metabolismo , Fito-Hemaglutininas , Proteínas Recombinantes , Linfócitos T/metabolismoRESUMO
En el presente estudio se evaluó la SP y MO de 21 pacientes, no tratados con diagnóstico de linfoma y provenientes de la Unidad de Linfomas del Hospital Universitario de Caracas. El protocolo de investigación incluyó parámetros clínicos e histológicos. En los grupos estudiados se evaluó el porcentaje de células killer naturales (NK) mediante el uso de anticuerpos monoclonales, así como la actividad NK basal postestimulación in vitro con 500/ml de IL 2. Los resultados muestran que los porcentajes de células en SP y MO son similares en pacientes con EH y LNH en relación al grupo de control
Assuntos
Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Anticorpos Monoclonais/imunologia , Células Matadoras Naturais/imunologia , Linfoma/diagnósticoRESUMO
We examined the effect of treatment with piroxicam, a nonsteroidal antiinflammatory drug (NSAID), on immunoglobulin (Ig) and IgM-rheumatoid factor (IgM-RF) synthesis in vitro by lymphocytes of patients with rheumatoid arthritis (RA). Oral treatment with piroxicam induced a progressive decrease of spontaneous IgM-RF production by unstimulated lymphocyte cultures during 12 weeks of observation. Also, pokeweed mitogen (PWM)-driven Ig synthesis was significantly diminished and the effect on total IgM production was sustained until the end of the study. This modulation of humoral responses is consistent with the drop in RF sera level. In addition, we also showed that treatment with NSAIDs can decrease RF levels in the synovial space. NSAIDs may have a long-term beneficial effect in patients with RA due to their modulatory role of lymphocyte responses.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Reumatoide/metabolismo , Imunoglobulina M/biossíntese , Imunoglobulinas/biossíntese , Fator Reumatoide/biossíntese , Administração Oral , Artrite Reumatoide/sangue , Células Cultivadas , Humanos , Imunoglobulina G/biossíntese , Leucócitos Mononucleares/metabolismo , Piroxicam/uso terapêutico , Mitógenos de Phytolacca americana/farmacologia , Líquido Sinovial/metabolismoRESUMO
In the present study we have examined the effect of human large granular lymphocytes (LGL) from healthy donors on Ig synthesis by autologous B lymphocytes. The results showed that this cell population has a consistent helper activity in pokeweed mitogen-activated cultures even when added at very low numbers. LGL can mediate their effect by secreting soluble helper factors capable of modulating B-cell responses as evidenced by the enhancement of IgG and IgM production by supernatants obtained from LGL cultures. Preincubation with interferon gamma further potentiated the helper activity by LGL.