Detection of early apoptosis and cell death in T CD4+ and CD8+ cells from lesions of patients with localized cutaneous leishmaniasis.
Braz J Med Biol Res
; 33(3): 317-25, 2000 Mar.
Article
em En
| MEDLINE
| ID: mdl-10719384
ABSTRACT
Human localized cutaneous leishmaniasis (LCL), induced by Leishmania braziliensis, ranges from a clinically mild, self-healing disease with localized cutaneous lesions to severe forms which can present secondary metastatic lesions. The T cell-mediated immune response is extremely important to define the outcome of the disease; however, the underlying mechanisms involved are not fully understood. A flow cytometric analysis of incorporation of 7-amino actinomycin D and CD4+ or CD8+ T cell surface phenotyping was used to determine whether different frequencies of early apoptosis or accidental cell death occur at different stages of LCL lesions. When all cells obtained from a biopsy sample were analyzed, larger numbers of early apoptotic and dead cells were observed in lesions from patients with active disease (mean = 39.5 +/- 2.7%) as compared with lesions undergoing spontaneous healing (mean = 17.8 +/- 2.2%). Cells displaying normal viability patterns obtained from active LCL lesions showed higher numbers of early apoptotic events among CD8+ than among CD4+ T cells (mean = 28.5 +/- 3.8 and 15.3 +/- 3.0%, respectively). The higher frequency of cell death events in CD8+ T cells from patients with LCL may be associated with an active form of the disease. In addition, low frequencies of early apoptotic events among the CD8+ T cells were observed in two patients with self-healing lesions. Although the number of patients in the latter group was small, it is possible to speculate that, during the immune response, differences in apoptotic events in CD4+ and CD8+ T cell subsets could be responsible for controlling the CD4/CD8 ratio, thus leading to healing or maintenance of disease.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
/
Leishmaniose Cutânea
/
Apoptose
/
Linfócitos T CD8-Positivos
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Braz J Med Biol Res
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Brasil