Bulgarian Academy of Sciences Institute of Microbiology, Sofia, Bulgaria
Petya Dimitrova
Dexamethasone and vitamin D3 expanded CD4+CD25+ T cells suppress disease activity in in MLR/lpr mice
Background
Reduced numbers of peripheral CD4+CD25+ T cells in SLE patients (Valencia X, Lipski P, J. Immunol. 2007, 178, 2579-2588); Low frequencies of CD4+CD25+ T cells in NZB/W lupusprone mice (Hsu WT, Clin. Exp. Immunol. 2006, 145, 513-519 ); Enhanced serum levels of anti-dsDNA antibodies and accelerated glomerulonephritis after the depletion of CD4+CD25+ T cells (Chiang BL, Clin. Exp. Immunol. 2006, 145, 513-519); Increased regulatory capacity of CD4+CD25+ T cells exposed to Dex & VitD3 (Barrat FJ, O’Garra A, J. Exp. Med. 2002, 195,
603-616).
Aim
To suppress the disease activity in MLR/lpr mice by Dex & VitD3 expanded CD4+CD25+ T cells.
CD4+CD25+ T cells in MLR/lpr mice
12 week-old
10
5
16 week-old
10
5
18 week-old
10
5
10
4
5.9%
10
4
6.6%
5 D 2
0 1
10
4
6.1%
% . 9 5
0 1 . % 6
C
0 1
C D 4
0 1
10
3
10
3
10
3
CD25
10
2
32.1%
10
2
10
2
35.4%
10
2
10
2
42.2%
10
2
10
3
10
4
10
5
10
3
10
4
10
5
10
3
10
4
10
5
CD4
T cell proliferation in vitro
Proliferation (cpm x 103)
CD4+CD25- T cells
40 80 60 40 20 0 VitD3 + Dex + + + PMA Yon * * * 30
CD4+CD25+ T cells
* 20 10 0
*
*
VitD3 + Dex -
+
+ +
-
PMA Yon
αCD3+αCD28 Abs α
αCD3+αCD28 Abs α
Regulatory capacity of CD4+CD25+ T cells
CD4+CD25+ T cells/CD4+CD25- T cells (5:1)
1.2
Index of suppression
1.0 0.8 0.6 0.4 0.2 0 CD25T cells + +
* *
+ +
-
Dex VitD3
CD25- + CD25+ T cells
Effect of Dex & VitD3 exposed CD25+ T cells on B cells
CD4+CD25+ T cells 120 Sup from T cell cultures
48 h
Dex ± VitD3
80
40
Spots/105 B cells
4 days
medium
CD25- T cells
0 120 Sup from T cell co-cultures * *
Supernatants (Sup) + CD19+ B cells
80 40
24 h Numbers of dsDNA-specific IgG producing B cells (ELISPOT) 0 VitD3 + Dex + + + -
Dex & VitD3 exposure: Effect on cytokines
10.0 Sup from T cell cultures 15 Sup from T cell co-cultures
IL-4 (pg/ml)
5.0
IL-4 (pg/ml)
10 * 5
2.5
0 15 **
0 20 ** * *
IL-10 (ng/ml)
10
IL-10 (ng/ml)
*
*
15 10
5
0
VitD3 + Dex -
+
+ +
-
0
VitD3 + Dex -
+
+ +
-
*p<0.05 **p<0.01
Dex & VitD3 exposure: Effect on p38 phosphorylation
IB: pp38 IB: p38 VitD3 Dex + + + + VitD3 Dex + + + +
IB: ppERK IB: β -actin
Dex & VitD3 exposure: T cell adoptive transfer data
Transfer groups
Serum levels of IgG anti-dsDNA antibodies (relative units) 48.4 ± 3.4*
Numbers of plasma cells producing IgG anti-dsDNA antibodies (spots/1x105) 54.3 ± 4.7*
CD4+CD25+ T cells (Dex+VitD3 exposed) CD4+CD25+ T cells (Medium pretreated) Control group (PBS injected)
75.6 ± 24.1
89.0 ± 15.2
100.0 ± 0.0
141.1 ± 14.2
*p<0.05 vs control group
Dex & VitD3 exposure: Summary
Dex & VitD3 exposure enhanced the suppressor activity of CD4+CD25+ T cells from MLR/lpr mice; This effect of Dex & VitD3-expanded CD25+ T cells was related to altered IL-10 and IL-4 production and to increased p38 phosphorylation; Adoptive transfer of Dex & VitD3-exposed CD25+ T cells decreased the serum levels of anti-dsDNA IgG antibodies and inhibited the number of dsDNA-specific IgG producing plasma cells.
Dex & VitD3 exposure: Conclusion
The adoptive transfer of Dex & VitD3exposed CD4+CD25+ T cells can be used as a novel therapeutic approach in SLE.
Acknowledgement
Institute of Microbiology, Sofia, Bulgaria
Prof. Dr. Tchavdar Vassilev
Institute of Infectious and Parasitic diseases, Sofia, Bulgaria
Dr. Maria Nikolova