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
Article
Dans Anglais
| 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.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Lymphocytes T
/
Molécules d'adhérence cellulaire
/
Cytokines
/
Dengue
/
Virus de la dengue
Type d'étude:
Étude observationnelle
/
Facteurs de risque
Limites du sujet:
Adolescent
/
Adulte
/
Adulte très âgé
/
Femelle
/
Humains
/
Mâle
langue:
Anglais
Texte intégral:
Mem. Inst. Oswaldo Cruz
Thème du journal:
Médecine tropicale
/
Parasitologie
Année:
2006
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Fundação Oswaldo Cruz/BR
/
Universidade Federal Fluminense/BR
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