slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Background PowerPoint Presentation
Download Presentation
Background

Loading in 2 Seconds...

play fullscreen
1 / 1

Background - PowerPoint PPT Presentation


  • 107 Views
  • Uploaded on

PBMCs. Gate: lymphocytes. Gate :CD4 + T cells. Side scatter. Activated Th1 and Th2-committed central memory CD4 +  T Cells are over-represented in HIV-infected patients , and have proliferative defects. Ki-67-FITC. Forward scatter. CD4-APC-Cy7. CD38 + pre-Th1 * 16.8%.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Background' - questa


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

PBMCs

Gate: lymphocytes

Gate :CD4+ T cells

Side scatter

Activated Th1 and Th2-committedcentral memory CD4+ T Cells are over-represented in

HIV-infected patients, and have proliferative defects

Ki-67-FITC

Forward scatter

CD4-APC-Cy7

CD38+pre-Th1*

16.8%

CD38+ pre-Th1

4.9%

CD38+pre-Th2

2.5%

CD38+pre-Th2**

12.2%

Gate: CD4+ T cells

Other CD38-

17.1%

CD45RA-PE-Texas-Red

Other CD38-

35.5%

CCR7-PE-Cy-7

S. Perez-Patrigeon1, E. Espinosa2,A. Mondragón-Eguiluz1, G. Olvera García2, U. Orbe2

1 Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico

2 Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico

Gate: non-committed

Gate: TcmCD4+

Ki-67-FITC

CXCR5-PerCP-Cy5.5

Gate: CXCR3- CCR4+

Gate: CXCR3+ CCR4-

Committed

Pre-Th2 CD38-

4.6%

Other CD38+

45.1%

Ki-67-FITC

Ki-67-FITC

Pre-Th2 CD38-

6.2%

Other CD38+

46.1%

Figure 1.- Activated pre-Th1 cells and activated pre-Th2 cells are over-represented within CD4+ TCM of HIV infected patients

Pre-Th1 CD38-

8.4%

Figure 4.- % CD38+ pre-Th1 of CD4+ TCM cells correlated with proliferative response of CD4+ T cells to CMV

Pre-Th1 CD38-

2.6%

Background

The mechanisms linking chronic immune activation and CD4+ T cell depletion in HIV infection remain poorly understood. In chronic HIV infection, loss of remnant critical levels of effector memory CD4+T cells has been related to a failure of central memory CD4+ T cells (TCM) to replenish this cell pool by proliferation and differentiation [1-4]. We hypothesized that TCM cells from HIV-infected patients would show an activation-driven commitment to differentiate to effector memory cells instead of proliferating upon TCR stimulation.

3.5

CD38-PerCP-Cy5.5

CD38-PerCP-Cy5.5

3

2.5

2

Percent Ki67+of total CD4+T cells

R=0.76, p=0.005

1.5

1

HIV-

0.5

HIV+

0

0

5

10

15

20

25

30

35

40

Materials and methods

Using flow cytometry, CD4+ TCM were identified among PBMCs of 6 untreated HIV infected patients and 5 controls. Pre-Th1 and pre-Th2 effector-committed cells were identified as CXCR5- and either CXCR3+ or CCR4+, respectively. Activation was determined by CD38 expression. Proliferative responses to SEB and HIV and CMV peptides were determined by Ki67 induction. Groups were compared with Mann-Whitney’s U test. Variables within groups were compared using Wilcoxon’s signed rank test. Correlations between variables were determined by linear regression.

Results

CD4+ TCMcells from patients had higher %activated Th1-committed cells and activated Th2-committed cells than controls (p= 0.037, p=0.025 correspondingly) (Fig.1). CD4+ TCM cells with a phenotype indicating pre-Th2 differentiation commitment had a decreased polyclonal proliferative response to SEB compared with uncommitted TCM cells (p=0.043 in patients, p=0.046 in controls) (Fig.2), while pre-Th1 CD4+ TCM cells from controls proliferated less frequently than uncommitted cells in response to SEB (p=0.028) (Fig. 3).

% CD38+Pre-Th1 ofTCM CD4+

3.5

3

2.5

Figure 5.- %CD38+ pre Th2 of TCM CD4+ cells correlated with proliferative response of CD4+ T cells to CMV

HIV-

2

Percent Ki-67+of total CD4+ T cells

HIV+

Total CD4+ TCM of Healthy donors

Total CD4+ TCM of HIV infected Patients

1.5

1

R=0.78, p=0.005

.5

0

0

1

2

3

4

5

6

7

8

9

Gating strategy

Figure 2.- Pre-Th2 CD4+ TCM proliferated less frequently than uncommitted cells upon polyclonal stimulus

# events

# events

% CD38+pre-Th2 of TCMCD4+

*p=0.043

  • Conclusions
  • Activated central memory CD4+ T cells with a phenotype indicating commitment to differentiate to Th1 and Th2 effector memory cells are over-represented among CD4+ TCM cells from HIV+patients. Their lower proliferative responses to TCR engagement could render CD4+ TCM less capable of regenerating the CD4+ T cell pool.
  • The correlation between the frequency of activated and committed CD4+ TCM cells and anti-CMV response suggests that activation-associated commitment in HIV infection is partially driven by CMV infection.

*p=0.046

40

35

30

25

% Ki-67+cells

HIV-

20

HIV+

15

Pre-Th2

Uncommitted

10

5

Proliferative responses of Tcm CD4+ with pre-Th2 (CXCR3- CCR4+) and uncommitted (CXCR5-) phenotype to SEB.

0

Figure 3.- Pre-Th1 CD4+ TCMproliferated less frequently than uncommitted cells upon polyclonal stimulus only in healthy controls

References

1. S. F. Sieg, C. V. Harding and M. M. Lederman, "HIV-1 infection impairs cell cycle progression of CD4(+) T cells without affecting early activation responses", Journal/J Clin Invest, vol. 108, no.5, pp. 757-764, 2001

2. M. Guadalupe, E. Reay, S. Sankaran, et al., "Severe CD4+ T-cell depletion in gut lymphoid tissue during primary human immunodeficiency virus type 1 infection and substantial delay in restoration following highly active antiretroviral therapy", Journal/J Virol, vol. 77, no.21, pp. 11708-11717, 2003

3. S. Mehandru, M. A. Poles, K. Tenner-Racz, et al., "Primary HIV-1 infection is associated with preferential depletion of CD4+ T lymphocytes from effector sites in the gastrointestinal tract", Journal/J Exp Med, vol. 200, no.6, pp. 761-770, 2004

4. A. Okoye, M. Meier-Schellersheim, J. M. Brenchley, et al., "Progressive CD4+ central memory T cell decline results in CD4+ effector memory insufficiency and overt disease in chronic SIV infection", Journal/J Exp Med, vol. 204, no.9, pp. 2171-2185, 2007

.

CXCR3-PE

*p=0.028

40

CCR4-AF647

35

30

25

HIV-

% of Ki-67+cells

20

HIV+

15

10

5

0

Pre-Th1

Uncommitted

Contact

espinosa@iner.gob.mx,ppsyago@gmail.com

Proliferative responses of TCMCD4+ with pre-Th1 (CXCR3+ CCR4-) phenotype and uncommitted (CXCR5-) phenotype to SEB.