CD8+ T-Cell Non-Cytotoxic Antiviral Response (CNAR) Suppresses SIV Replication

Meenakshi Vanka

Emory University, Class of 2013

Sacha Lab, Oregon National Primate Research Center

Overview Introduction to HIV/AIDS epidemicCD8+ T-cells and HIV infection CD8+ T-cell Non-Cytotoxic Antiviral Response

(CNAR)

HIV: A Global Epidemic

• CD4+ T-cells

• CD8+ T-cells

HIV infection

• SIV

• HIV

Course of infection

Matano et al. (1998), Jin et al. (1999), Schmitz et al. (1999), Metzner et al. (2000)

plas

ma

vira

l con

cent

ratio

n

Weeks Years

Role of CD8+ T-Cells H

IV-s

peci

fic C

D8

freq

uenc

y

plas

ma

vira

l con

cent

ratio

n

Matano et al. (1998), Jin et al. (1999), Schmitz et al. (1999), Metzner et al. (2000)

Weeks Years

Cytotoxic CD8+ T-cell function

CD4+ T-cellSIV

CD8+ T-cell

CD8+ T-Cell Non-Cytotoxic Antiviral Response (CNAR)

CD8+ T-cell suppression of viral replication without killing infected cells.

Mediated by soluble Cell Antiviral Factor (CAF).Does not depend on cell contact.Present in HIV infected individuals, but not naive

individuals. Positively correlated with an asymptomatic

clinical state.

Non-Cytotoxic CD8+ T-cell function

CD4+ T-cellSIV

CD8+ T-cell

CAF

ObjectivesTo optimize assay set up and test CNAR activity in

the rhesus macaque model. To better characterize protective CD8+ T-cell anti-SIV

activity.

HypothesisViremic controllers and SIV vaccinated (CMV

vector) animals will exhibit CNAR activity.

Methods1. Isolate lymphocytes from animal blood.

Activation

CD4+ T-cell CD8+ T-cell

2. Isolate CD4 T-cells and CD8 T-cells.

3. Activate CD4 and CD8 T-cells in vitro.

Methods (continued)

Add CD8+effectors

SIV

SIV-infected CD4+ T-cells (Targets)

CD4+ T-cells

Infect CD4+ T-cells with SIV.

Co-culture CD8+ Effectors and CD4+ Targets.

Stain for virus.

Cell Population Analysis

Gag p27

CD4

Uninfected 7 days Post Infection

.013 31.9

Viral Suppression

Gag p27

CD4

No CD8+ T-cells added CD8+ T-cells added

39.9 15.7

CNAR activity in viremic controllers

0

10

20

30

40

50

60

70

80

90

100

Viremic Controller 1 (22559)Viremic Controller 2 (22642)

Effector:Target Ratio

Perc

ent G

ag p

27 S

uppr

essio

n

.25:1 .5:1 1:1 2:1

CNAR activity in SIV vaccinated (CMV vector) animals

0

10

20

30

40

50

60

70

80

90

100

23716

24513

24552

Effector:Target Ratio

Perc

ent G

ag p

27 S

uppr

essio

n

.25:1 .5:1 1:1 2:1

CNAR activity in naïve animals

.25:1 .5:1 1.:12:1

0

10

20

30

40

50

60

70

80

90

Naïve Animal 1 (30673)Naïve Animal 2 (30674)

Effector:Target Ratio

Perc

ent G

ag p

27 S

uppr

essio

n

CNAR activity in MHC mismatched animals

0

10

20

30

40

50

60

70

80

90

100

22559 E/28401 T22559 E/27603 T22642 E/28401 T22642 E/27603 TViremic Controller 1 (22559)Viremic Controller 2 (22642)

Effector:Target Ratio

Perc

ent G

ag p

27 S

uppr

essio

n

.25:1 .5:1 1:1 2:1

Summary The CD8+ T-Cell Non-Cytotoxic Antiviral

Response (CNAR) best suppresses SIV replication in viremic controllers and SIV vaccinated (CMV vector)/SIV protected animals.

These findings reinforce CNAR activity seen in HIV infected individuals.

Future DirectionsPerform transwell assays to confirm that CNAR

is mediated by soluble Cell Antiviral Factor

(CAF). non-cytolytic in nature.

Screen more naïve animals to determine whether CNAR is an SIV specific response.

Acknowledgements

Ben Burwitz Jonah SachaJason ReedEnrique LeonSilver Family Foundation