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, Mar. 2000. ilus, graf
Article
in English
| LILACS
| ID: lil-255052
RESUMO
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 + or - 2.7 per cent) as compared with lesions undergoing spontaneous healing (mean = 17.8 + or - 2.2 per cent). 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 + or - 3.8 and 15.3 + or - 3.0 per cent, 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.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
CD4-Positive T-Lymphocytes
/
Leishmaniasis, Cutaneous
/
Apoptosis
/
CD8-Positive T-Lymphocytes
Type of study:
Diagnostic study
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2000
Type:
Article
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