CD4 and CD8 distribution profile in individuals infected by Schistosoma mansoni.
BACKGROUND
Patients with chronic Schistosoma mansoni infection show lower anti-soluble egg antigen (SEA) proliferation responses and higher responses to soluble worm antigen preparation (SWAP).


OBJECTIVE
To compare the activation status and proliferation response of peripheral blood mononuclear cells (PBMC) of infected (XTO) and egg-negative individuals (NI) living in the same endemic area.


METHODS
XTO (n = 51) and NI individuals from the same geographical area (n = 37) and healthy blood donors (n = 22) were evaluated before and after stimulation with SEA and SWAP. The expression of activation markers (CD4(+) HLADR(+), CD8(high+)HLA-DR(+) and CD8(+) CD28(+)) and proliferation assay was assessed by flow cytometry.


RESULTS
PBMC from infected patients showed lower frequency of CD4(+) but no change in CD8(+) T cells when compared with the healthy donor group. The ratio CD4(+)/CD8(+) was 1.3, 0.6 and 0.5 in healthy donors, infected and non-infected individuals, respectively. The HLA-DR(+) expression on CD8(+) was higher in PBMC from infected and non-infected individuals than from healthy donors, but similar in both total lymphocytes and CD4(+) populations. No intergroup proliferation response differences were observed in CD4(+) and CD8(+) PBMC unstimulated and stimulated with SEA and SWAP. The SEA but not SWAP-stimulated cells showed a decrease in the expression of phosphorylated extracellular signal-regulated kinase (ERK1/2).


CONCLUSIONS
XTO and NI individuals living in the same area presented a smaller per cent of CD4(+) and a higher per cent of CD8(+) cells. The activation by either CD8(high+)HLA-DR(+) or CD8(high+)HLA-DR(+)/CD8(+) was enhanced and decreased in XTO and NI by CD8(+) CD28(+) and CD8(+) CD28(+)/CD8(+) when compared with healthy donor. ERK phosphorylation was attenuated in XTO and NI individuals when stimulated with SEA but not SWAP.
Oliveira-Prado
R
R
Department of Pathology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
Caldas
I R
IR
Teixeira-Carvalho
A
A
Andrade
M V
MV
Gazzinelli
A
A
Correa-Oliveira
R
R
Cunha-Melo
J R
JR
D000293:Adolescent; D000328:Adult; D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D019950:Mitogen-Activated Protein Kinase 1 / Q000276:immunology / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation; D012550:Schistosoma mansoni / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000947:Antigens, Helminth; D018106:CD28 Antigens; D006684:HLA-DR Antigens; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3