1. EFFECTS OF VIRUS INFECTION IN CD4+ T CELLS
Pavel Bostik
FMHS
Charles University Medical School
University Hospital
Hradec Kralove
Czech Republic

2. AICD OF CD4 T CELLS AND VIRUS INFECTION
Select viruses (HIV, VZV, measles, EBV, CMV..) directly infect immune effector cells
Some viruses infect CD4+ T cells and induce aberrant signaling and apoptosis
AICD – activated T cells undergo apoptosis
Effects of viruses can be direct (infection) or indirect (binding of virus derived proteins to cell receptors
Certain infections lead to chronic activation of immune system

3. SURVIVAL/APOPTOSIS of T CELLS
APC
Cytokine
TCR/
CD28
CD4
CD3
Receptor p
lck
ZAP
Thr308
Akt p 70
PDK1
Ser473
PTEN
PI3K
PIP3
GSK3
So now I investigated what happened when the T cells were stimulated.
Cot
MAPK
COX2
PGE2
NFkB
p53
Cell death
Transcription

4. VZV strain identification on the basis of genome variability
is an essential part of post immunization surveillance.
facilitates better analysis of VZV evolution and recombination and the effect of these on pathogenesis
Allows for better understanding of VZV epidemiology, including facilitating identification of the source of VZV outbreaks.

5. EFFECT of VZV on APOPTOSIS of T CELLS
Peripheral
blood
CD4+ T cells
FLOW ANALYSIS
CD3/CD28

6. EFFECT of VZV on APOPTOSIS of T CELLS

7. SURVIVAL/APOPTOSIS of T CELLS
APC
Cytokine
TCR/
CD28
CD4
CD3
Receptor
Thr308 p
lck
ZAP
Akt p 70
PDK1
Ser473
PTEN
PI3K
LY294002
PIP3
GSK3
LiCl
So now I investigated what happened when the T cells were stimulated.
Cot
MAPK
Niflumic Acid
COX2
PGE2
NFkB
p53
Cell death
Transcription

9. KINASES in VZV INFECTED CELLS

10. KINASES in VZV INFECTED CELLS

11. CONCLUSIONS
VZV infects CD4+ T cells and level of infection is dependent on the particular subtype-virulence
Infection of CD4+ T cells leads to the increase in apoptosis and VZV+ cells are apoptotic
Inhibition of prostaglandin pathway decreases VZV effects
VZV infection leads to the regulation of the Akt phosporylation independent of the PI3K stimulatory pathway
Inhibition of GSK3beta is not circumvented by VZV and activation

12. HIV-2 HIV-1 (M,N, O) ORIGIN OF HIV Cercocebus atys SIVsm
Pan troglodytes)
SIVcpz
Macacca mulata
HIV-2
HIV-1 (M,N, O)

13. APOPTOSIS OF CD4+ T CELLS**
APOPTOSIS OF CD4+ T CELLS
Here we measured apoptosis in CD4+ T cells from each of our cohorts via Annexin-V binding to phosphatidylserine expressed on the surface of cells. This is an indicator of early-stage apoptosis.
GSK3b is one of the kinases identified to be dysregulated in SIV+ RM
Bostik et al.,J Virol 2001.

14. EFFECT OF ACTIVATION ON pAKT

15. AKT Thr308 phosphorylation in CD4+ T cells from SIV+ RM

16. AICD **
***
p<0.05
p<0.001 *
No Change

17. CONCLUSIONS
GSK-3b transcription IS markedly reduced not only at the message level but also at the level of protein expression in CD4+ T cells from SIV+RM
Baseline levels of Akt and p-AktThr308 are comparable, the levels of phosphorylated AktSer 473 are significantly lower in cells from SIV+ SM compared to the SIV+ RM
Stimulation of CD4+ T cells leads to a marked increase in both total Akt and *p-AktThr308 in the SIV+RM, which correlates to increased susceptibility for AICD
Phosphorylation differences of Akt at Ser473 and Thr308 in anti-CD3/CD28 activated CD4+ T cells are both species and CD4+ T cell sub-population specific

18. Thank you for your attention
M. Schmidt
V. Bostik
R.Sleha
Emory University S. Stephenson F. Villinger
Support:
AZV CZ
GACR CZ
NIH

19. KINASES in VZV INFECTED CELLS