Activated peripheral lymphocytes with increased expression of cell adhesion molecules and cytotoxic markers are associated with dengue fever disease
Mem. Inst. Oswaldo Cruz
;
101(4): 437-449, June 2006. graf, tab
Artículo
en Inglés
| LILACS
| ID: lil-435307
ABSTRACT
The immune mechanisms involved in dengue fever and dengue hemorrhagic/dengue shock syndrome are not well understood. The ex vivo activation status of immune cells during the dengue disease in patients was examined. CD4and CD8 T cells were reduced during the acute phase. Interestingly, CD8 T cells co-expressing activation marker HLA-DR, Q, P, and cytolytic granule protein-Tia-1 were significantly higher in dengue patients than in controls. Detection of adhesion molecules indicated that in dengue patients the majority of T cells (CD4 and CD8) express the activation/memory phenotype, characterized as CD44HIGH and lack the expression of the naïve cell marker, CD62L LOW. Also, the levels of T cells co-expressing ICAM-1 (CD54), VLA-4, and LFA-1 (CD11a) were significantly increased. CD8 T lymphocytes expressed predominantly low levels of anti-apoptotic molecule Bcl-2 in the acute phase, possibly leading to the exhibition of a phenotype of activated/effector cells. Circulating levels of IL-18, TGF-b1 and sICAM-1 were significantly elevated in dengue patients. Early activation events occur during acute dengue infection which might contribute to viral clearance. Differences in expression of adhesion molecules among CD4 and CD8 T cells might underlie the selective extravasation of these subsets from blood circulation into lymphoid organs and/or tissues. In addition, activated CD8 T cells would be more susceptible to apoptosis as shown by the alteration in Bcl-2 expression. Cytokines such as IL-18, TGF-b1, and sICAM-1 may be contributing by either stimulating or suppressing the adaptative immune response, during dengue infection, thereby perhaps establishing a relationship with disease severity.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Linfocitos T
/
Moléculas de Adhesión Celular
/
Citocinas
/
Dengue
/
Virus del Dengue
Tipo de estudio:
Estudio observacional
/
Factores de riesgo
Límite:
Adolescente
/
Adulto
/
Anciano
/
Femenino
/
Humanos
/
Masculino
Idioma:
Inglés
Revista:
Mem. Inst. Oswaldo Cruz
Asunto de la revista:
Medicina Tropical
/
Parasitología
Año:
2006
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
Fundação Oswaldo Cruz/BR
/
Universidade Federal Fluminense/BR
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