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Up-regulated S100 calcium binding protein A8 in Plasmodium-infected patients correlates with CD4(+)CD25(+)Foxp3 regulatory T cell generation.

Lee HW, Kim TS, Kang YJ, Kim JY, Lee S, Lee WJ, Sohn Y - Malar. J. (2015)

Bottom Line: A higher amount of S100A8 was detected in vivax-infected patients (141.2 ± 61.849 ng/ml, n = 40) compared with normal control group (48.1 ± 27.384 ng/ml, n = 40).The level of S100A8 did not coincide with that of anti-malarial antibody measured by indirect fluorescent antibody test (IFAT) using parasite-infected red blood cells as antigen.However, the serum levels of S100A8 decreased with increase in parasitaemia.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, 32610, USA. rainlee67@naver.com.

ABSTRACT

Background: The pro-inflammatory S100 calcium binding protein A8 (S100A8) is elevated in the serum of patients with Plasmodium falciparum malaria, but its function in Plasmodium vivax malaria is not yet clear. This function was investigated in P. vivax-infected patients in this study.

Methods: The level of S100A8 in the serum was measured with ELISA. Full amino acids of S100A8 were synthesized to verify the functions for maturation of immature dendritic cell (iDC) and evaluation of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) generation by mature DC (mDC).

Results: A higher amount of S100A8 was detected in vivax-infected patients (141.2 ± 61.849 ng/ml, n = 40) compared with normal control group (48.1 ± 27.384 ng/ml, n = 40). The level of S100A8 did not coincide with that of anti-malarial antibody measured by indirect fluorescent antibody test (IFAT) using parasite-infected red blood cells as antigen. Programmed death-ligand 1 (PD-L1) was up-regulated on the surface of iDCs following treatment with synthetic S100A8, not with synthetic MSP-1, AMA-1 and CSP, as compared to the expression seen for non-treated iDCs. The addition of red blood cells of infected patients to iDCs also elevated their surface expression of CD86. However, the serum levels of S100A8 decreased with increase in parasitaemia. DCs matured by sera containing S100A8 generated Treg cells from naïve T cells. The ratio of Treg cells generated was inversely proportional to the concentration of S100A8 in sera.

Conclusions: Treg cells suppress the activity of cytotoxic T cells, which kill malaria parasites; therefore, the up-regulation of S100A8 in malaria patients may contribute to pathogen immune escape or tolerance.

No MeSH data available.


Related in: MedlinePlus

Comparison of the DC maturation state between LPS and synthetic peptides, S100A8, CSP, AMA-1, and MSP-1. DC maturation as determined by the expression levels of CD86, HLA-DR, and PDL-1 by several synthetic peptides. The relative increase in surface expression is expressed as the mean fluorescence intensity (MFI) of matured DCs over the MFI of iDCs. A representative result of three repeated experiments is shown for FACS analysis. Significant differences were determined using one-way ANOVA followed by Bonferroni’s multiple comparison tests (*P < 0.05, **P < 0.01, ***P < 0.001)
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Fig5: Comparison of the DC maturation state between LPS and synthetic peptides, S100A8, CSP, AMA-1, and MSP-1. DC maturation as determined by the expression levels of CD86, HLA-DR, and PDL-1 by several synthetic peptides. The relative increase in surface expression is expressed as the mean fluorescence intensity (MFI) of matured DCs over the MFI of iDCs. A representative result of three repeated experiments is shown for FACS analysis. Significant differences were determined using one-way ANOVA followed by Bonferroni’s multiple comparison tests (*P < 0.05, **P < 0.01, ***P < 0.001)

Mentions: To determine the effect of S100A8 on DC maturation, immature myeloid DCs were generated by culturing CD14+ PBMCs in the presence of GM-CSF and IL-4 for 3 days, followed by incubation with synthetic S100A8, MSP-1, AMA-1, CSP, and LPS for 48 h. Expression of the DCs’ maturation markers, CD86, HLA-DR and PD-L1, were then assessed by flow cytometric analysis. When comparing the expression levels of HLA-DR and PD-L1, 14.3 % of the untreated controls were found to be double-positive, whereas LPS induced high levels of expression on the iDC surface, with 82.5 % of cells being double-positive, followed by 45.5 % cells showing positivity for S100A8, 35.8 % for CSP, 29.0 % for AMA-1, and 19.5 % for MSP-1 (Fig. 4). LPS (P < 0.001) and synthetic S100A8 (P < 0.05) displayed significant elevations of CD86, HLA-DR and PD-L1; however, the CSP, MSP-1 and AMA-1 synthetic peptides were found to have no significant effect on induction on comparison with control, untreated iDCs (Fig. 5). The effect of parasite-infected RBCs (Fig. 6) containing S100A8, as verified by ELISA, were then tested on DC maturation. Notably, infected RBCs’ crude antigen significantly increased the expression of CD86 on iDCs (P = 0.0019, n = 5, Fig. 6b). It means that some components of malaria parasites may directly affect DC maturation or induce the expression of S100A8 in iDC, which is used in DC maturation as self-feeding manner to be matured DC.Fig. 4


Up-regulated S100 calcium binding protein A8 in Plasmodium-infected patients correlates with CD4(+)CD25(+)Foxp3 regulatory T cell generation.

Lee HW, Kim TS, Kang YJ, Kim JY, Lee S, Lee WJ, Sohn Y - Malar. J. (2015)

Comparison of the DC maturation state between LPS and synthetic peptides, S100A8, CSP, AMA-1, and MSP-1. DC maturation as determined by the expression levels of CD86, HLA-DR, and PDL-1 by several synthetic peptides. The relative increase in surface expression is expressed as the mean fluorescence intensity (MFI) of matured DCs over the MFI of iDCs. A representative result of three repeated experiments is shown for FACS analysis. Significant differences were determined using one-way ANOVA followed by Bonferroni’s multiple comparison tests (*P < 0.05, **P < 0.01, ***P < 0.001)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4594961&req=5

Fig5: Comparison of the DC maturation state between LPS and synthetic peptides, S100A8, CSP, AMA-1, and MSP-1. DC maturation as determined by the expression levels of CD86, HLA-DR, and PDL-1 by several synthetic peptides. The relative increase in surface expression is expressed as the mean fluorescence intensity (MFI) of matured DCs over the MFI of iDCs. A representative result of three repeated experiments is shown for FACS analysis. Significant differences were determined using one-way ANOVA followed by Bonferroni’s multiple comparison tests (*P < 0.05, **P < 0.01, ***P < 0.001)
Mentions: To determine the effect of S100A8 on DC maturation, immature myeloid DCs were generated by culturing CD14+ PBMCs in the presence of GM-CSF and IL-4 for 3 days, followed by incubation with synthetic S100A8, MSP-1, AMA-1, CSP, and LPS for 48 h. Expression of the DCs’ maturation markers, CD86, HLA-DR and PD-L1, were then assessed by flow cytometric analysis. When comparing the expression levels of HLA-DR and PD-L1, 14.3 % of the untreated controls were found to be double-positive, whereas LPS induced high levels of expression on the iDC surface, with 82.5 % of cells being double-positive, followed by 45.5 % cells showing positivity for S100A8, 35.8 % for CSP, 29.0 % for AMA-1, and 19.5 % for MSP-1 (Fig. 4). LPS (P < 0.001) and synthetic S100A8 (P < 0.05) displayed significant elevations of CD86, HLA-DR and PD-L1; however, the CSP, MSP-1 and AMA-1 synthetic peptides were found to have no significant effect on induction on comparison with control, untreated iDCs (Fig. 5). The effect of parasite-infected RBCs (Fig. 6) containing S100A8, as verified by ELISA, were then tested on DC maturation. Notably, infected RBCs’ crude antigen significantly increased the expression of CD86 on iDCs (P = 0.0019, n = 5, Fig. 6b). It means that some components of malaria parasites may directly affect DC maturation or induce the expression of S100A8 in iDC, which is used in DC maturation as self-feeding manner to be matured DC.Fig. 4

Bottom Line: A higher amount of S100A8 was detected in vivax-infected patients (141.2 ± 61.849 ng/ml, n = 40) compared with normal control group (48.1 ± 27.384 ng/ml, n = 40).The level of S100A8 did not coincide with that of anti-malarial antibody measured by indirect fluorescent antibody test (IFAT) using parasite-infected red blood cells as antigen.However, the serum levels of S100A8 decreased with increase in parasitaemia.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, 32610, USA. rainlee67@naver.com.

ABSTRACT

Background: The pro-inflammatory S100 calcium binding protein A8 (S100A8) is elevated in the serum of patients with Plasmodium falciparum malaria, but its function in Plasmodium vivax malaria is not yet clear. This function was investigated in P. vivax-infected patients in this study.

Methods: The level of S100A8 in the serum was measured with ELISA. Full amino acids of S100A8 were synthesized to verify the functions for maturation of immature dendritic cell (iDC) and evaluation of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) generation by mature DC (mDC).

Results: A higher amount of S100A8 was detected in vivax-infected patients (141.2 ± 61.849 ng/ml, n = 40) compared with normal control group (48.1 ± 27.384 ng/ml, n = 40). The level of S100A8 did not coincide with that of anti-malarial antibody measured by indirect fluorescent antibody test (IFAT) using parasite-infected red blood cells as antigen. Programmed death-ligand 1 (PD-L1) was up-regulated on the surface of iDCs following treatment with synthetic S100A8, not with synthetic MSP-1, AMA-1 and CSP, as compared to the expression seen for non-treated iDCs. The addition of red blood cells of infected patients to iDCs also elevated their surface expression of CD86. However, the serum levels of S100A8 decreased with increase in parasitaemia. DCs matured by sera containing S100A8 generated Treg cells from naïve T cells. The ratio of Treg cells generated was inversely proportional to the concentration of S100A8 in sera.

Conclusions: Treg cells suppress the activity of cytotoxic T cells, which kill malaria parasites; therefore, the up-regulation of S100A8 in malaria patients may contribute to pathogen immune escape or tolerance.

No MeSH data available.


Related in: MedlinePlus