Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos...
-
Upload
dennis-scott -
Category
Documents
-
view
220 -
download
4
Transcript of Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos...
![Page 1: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/1.jpg)
Universidade Federal do Rio de JaneiroCentro de Ciências da Saúde
Instituto de Biofísica Carlos Chagas Filho
The importance of apoptosis for immune regulation in Chagas’ disease
George A. DosReis
![Page 2: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/2.jpg)
Fabrício Montalvão. IBCCF-UFRJLandi V. Guillermo. IBCCF-UFRJ
Geisy M. de Almeida. IBCCF-UFRJElizabeth M. Silva. IBCCF-UFRJ
Marise P. Nunes. IOC-Fiocruz-RJJuliana de Meis. IOC-Fiocruz-RJ
Christina M. Takiya. Dept. Histologia-UFRJRichard Siegel. NIAID-NIH, USA
Celio Freire-de-Lima. IBCCF-UFRJMarcela F. Lopes. IBCCF-UFRJ
![Page 3: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/3.jpg)
Lopes MF et al. Immunol. Today 21; 489-494, 2000Freire-de-Lima CG et al. Nature 403; 199-203, 2000
Phagocytosis of apoptotic cells (efferocytosis) inactivates macrophages and exacerbates parasite replication through TGF-β, ODC and polyamine synthesis
X
Efferocytosis
![Page 4: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/4.jpg)
T. cruzi infection: Consequences of apoptosis
Efferocytosis
![Page 5: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/5.jpg)
Apoptosis in T. cruzi infection
Modify efferocytosis by:
1. Caspase inhibition2. Anti-FasL treatment3. Antibodies to apoptotic cells
Efferocytosis
![Page 6: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/6.jpg)
Blocking apoptosis in T. cruzi infection
Caspase inhibition
Efferocytosis
![Page 7: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/7.jpg)
Caspase inhibition reduces lymphocyte apopotosis in vivo
Silva, E. M. et al. Caspase inhibition reduces lymphocyte apoptosis and improves host immune responses to Trypanosoma cruzi infection. Eur. J. Immunol. 2007, 37 (3), 738-746.
![Page 8: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/8.jpg)
Treatment with zVAD reduces parasitemia
10 15 20 25 30 35 400
10
20
30
40
50
60
70
80
90
100
zVAD
zFA
control
Days post infection
Par
asit
es x
10
4/m
l
10 15 20 25 30 35 400
10
20
30
40
z-VAD
z-FAcontrol
Days post infectionP
aras
ites
x 1
04/m
l
Silva, E. M. et al. Caspase inhibition reduces lymphocyte apoptosis and improves host immune responses to Trypanosoma cruzi infection. Eur. J. Immunol. 2007, 37 (3), 738-746.
![Page 9: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/9.jpg)
Treatment with zVAD in vivo increases macrophage activation
![Page 10: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/10.jpg)
The general caspase inhibitor zVAD
reduces apoptosis of T lymphocytes in vitro
and in vivo
Treatment with zVAD increases immunity
to T. cruzi infection
![Page 11: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/11.jpg)
Blocking apoptosis in T. cruzi infection
Anti-FasL
Efferocytosis
![Page 12: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/12.jpg)
Increased immunity to T. cruzi after treatment with anti-FasL in vivo
Guillermo, L.V. et al. The Fas death pathway controls coordinated expansions of type 1 CD8 and type 2 CD4 T cells in Trypanosoma cruzi infection. J. Leukoc. Biol. 2007, 81, 942-951.
![Page 13: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/13.jpg)
Anti-FasL in vivo accelerates and increases type 1 cytokine responses
![Page 14: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/14.jpg)
Anti-FasL reduces apoptosis of CD4 and CD8 T cells
Anti-FasL increases type 1 cytokine responses, increases macrophage NO production and reducesparasitemia
Lymphocyte apoptosis is deleterious for T. cruziInfection in vivo
![Page 15: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/15.jpg)
Modifying immune regulation throughopsonization of apoptotic cells
Antibodies
Efferocytosis
![Page 16: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/16.jpg)
Differential reaction of chagasic IgG with apoptotic lymphocytes
1 10 100 1000
0
20
40
60
80
100
% o
f M
ax
Annexin V+
CHACT - 26.1%
CHA - 36.3%
IgG (H+L)
A
10000
OD (Arbitrary Units)
Migration Distance (Arbitrary Units)
CT
400 600 800 1000
50
40
30
20
10
0
B
C
Position 403
Pea
k va
lues
(A
U)
Position 901 Position 1055Position 1022
Cha
![Page 17: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/17.jpg)
0
2
4
6
8
10Parasite number (x104)
CT CHA CT CHA
None IgG IgM
None APO
**
Opsonization of apoptotic cells with chagasic IgG reduces the effect of efferocytosison replication of T. cruzi
IgG purified from T. cruzi infection(90 days) or age matched serum
![Page 18: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/18.jpg)
Control of parasite replication is mediated by increased TNF-α production
Apoptotic cells opsonized with chagasic IgGincrease TNF-α production
02468
101214
NoneAnti-TNF-Rat IgG1
Parasite number (x10 5)
CT CHA None IgG
None APO
** **
0
200
400
600
800
1000
1200
NoneAPOAPO/CT IgGAPO/CHA IgG
TNF- (pg/ml)
**
A
B
![Page 19: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/19.jpg)
Control of parasite replicationrequires engagement of FcγRs
0
3
6
9
12
15
ControlChagasic
Parasite number (x104)
IgG IgG F(ab') 2
None APO
**
0
4
8
12
16
20Control FabCD16/CD32 Fab
Parasite number (x104)
Control Chagasic
None IgG APO
**
A
B
![Page 20: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/20.jpg)
Previous immunization with apoptotic cells reduces parasitemia in vivo
0 5 10 15 200
1020304050607080
Saline/Al(OH)3APO/Al(OH)3
Parasitemia (x104/mL)
**
Dm28c
dpi
![Page 21: Universidade Federal do Rio de Janeiro Centro de Ciências da Saúde Instituto de Biofísica Carlos Chagas Filho The importance of apoptosis for immune regulation.](https://reader035.fdocuments.us/reader035/viewer/2022062421/56649dd35503460f94aca325/html5/thumbnails/21.jpg)
Conclusions Chagasic IgG opsonizes apoptotic cells and reduces the effect of efferocytosis on parasite replication
The protective effect is mediated by increased TNF-α production
The protective effect requires FcγRs
Generation of autoantibodies against apoptotic cell antigens could play a protective role against parasite infection