Are increased frequency of macrophage-like and natural killer (NK) cells, together with high levels of NK T and CD4+CD25high T cells balancing activated CD8+ T cells, the key to control Chagas'disease morbidity?.
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Data
2006
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Resumo
The immunological response during early human
Trypanosoma cruzi
infection
is not completely understood, despite its role in driving the development
of distinct clinical manifestations of chronic infection. Herein we report the
results of a descriptive flow cytometric immunophenotyping investigation of
major and minor peripheral blood leucocyte subpopulations in
T. cruzi
-
infected children, characterizing the early stages of the indeterminate clinical
form of Chagas’ disease. Our results indicated significant alterations by comparison
with uninfected children, including increased values of pre-natural
killer (NK)-cells (CD3
–
CD16
+
CD56
–
), and higher values of proinflammatory
monocytes (CD14
+
CD16
+
HLA-DR
++
). The higher values of activated B lymphocytes
(CD19
+
CD23
+
) contrasted with impaired T cell activation, indicated
by lower values of CD4
+
CD38
+
and CD4
+
HLA-DR
+
lymphocytes, a lower frequency
of CD8
+
CD38
+
and CD8
+
HLA-DR
+
cells; a decreased frequency of
CD4
+
CD25
HIGH
regulatory T cells was also observed. These findings reinforce
the hypothesis that simultaneous activation of innate and adaptive immunity
mechanisms in addition to suppression of adaptive cellular immune response
occur during early events of Chagas’ disease. Comparative cross-sectional
analysis of these immunophenotypes with those exhibited by patients with
late chronic indeterminate and cardiac forms of disease suggested that a shift
toward high values of macrophage-like cells extended to basal levels of proinflammatory
monocytes as well as high values of mature NK cells, NKT and
regulatory T cells, may account for limited tissue damage during chronic
infection favouring the establishment/maintenance of a lifelong indeterminate
clinical form of the disease. On the other hand, development of an adaptive
cell-mediated inflammatory immunoprofile characterized by high levels
of activated CD8
+
cells and basal levels of mature NK cells, NKT and
CD4
+
CD25
HIGH
cells might lead to late chronic pathologies associated with
chagasic heart disease.
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Palavras-chave
Flow cytometry, Peripheral blood, Recent infection
Citação
AVELAR, D. M. V. et al. Are increased frequency of macrophage-like and natural killer (NK) cells, together with high levels of NK T and CD4+CD25high T cells balancing activated CD8+ T cells, the key to control Chagas'disease morbidity?. Clinical and Experimental Immunology, v. 145, p. 81-92, 2006. Disponível em: <http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2249.2006.03123.x/abstract>. Acesso em: 20 jan. 2017.