Role of Natural Killer Cells in Vaccine-Elicited Control of HIV/SIV Infections
Download
1 / 21

Role of Natural Killer Cells in Vaccine-Elicited Control of HIV - PowerPoint PPT Presentation


  • 231 Views
  • Uploaded on

Role of Natural Killer Cells in Vaccine-Elicited Control of HIV/SIV Infections R. Keith Reeves, Ph.D. Division of Immunology NEPRC, Harvard Medical School November 19, 2009. Natural cytotoxicity.

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 'Role of Natural Killer Cells in Vaccine-Elicited Control of HIV' - Mercy


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 l.jpg

Role of Natural Killer Cells in Vaccine-Elicited Control of HIV/SIV Infections R. Keith Reeves, Ph.D. Division of Immunology NEPRC, Harvard Medical SchoolNovember 19, 2009


Slide2 l.jpg

Natural cytotoxicity HIV/SIV Infections

Killing of virus-infected and tumor cells

Two-signal killing


Slide3 l.jpg

In human peripheral blood, 2 primary NK subsets HIV/SIV Infections

CD56brightCD16-/dim,CD56dimCD16+

NK cells in rhesus macaques Poorly defined – CD3-CD16+

Webster & Johnson, Immunology, 2005


Natural killer cells in tissues l.jpg
Natural killer cells in tissues HIV/SIV Infections

  • Little is known about the phenotype of NK cells in tissues other than blood of humans and macaques

    • CD56bright NK cells in human LNs, placenta, and gut mucosa

  • Transmission and replication of lentiviruses primarily take place at mucosal sites and associated secondary lymphoid tissues


Objectives l.jpg
Objectives HIV/SIV Infections

  • To characterize NK cell subsets in blood and tissues of normal rhesus macaques and correlate functionality with discrete cellular phenotypes

  • To examine NK cell function in blood and tissues of macaques infected with wild-type or live attenuated SIV


Nk cell gating l.jpg
NK cell gating HIV/SIV Infections

DC/B cell exclusion

HLA-DR

SSC

FSC

CD45

CD8αα

T cell exclusion

Macaque NK phenotype in PBMC/tissues:

CD45+CD8αα+CD3- NKG2A+ CD20-/dim

NKG2A

CD8αα

CD20

CD3


Slide7 l.jpg

NK cell heterogeneity HIV/SIV Infections

Mucosal

Lymph Nodes


Natural killer cell subset distribution in tissues of rhesus macaques l.jpg
Natural killer cell subset distribution in tissues of rhesus macaques

CD56

“Standard” NK cells nearly absent from mucosae and LN

CD16


Slide9 l.jpg

NK cell subset functionality macaques

Up to 4-function polychromatic flow cytometry assay measuring activity against the MHC-devoid cell line 721.221


Slide10 l.jpg

NK cell subset functionality macaques

CD16+

CD56+

DN

% responding cells

IFN-γ

TNF-α

MIP-1β

CD107a

Similar division of labor as seen in human subsets

- Unique functionality of undescribed DN subset

Underappreciated complexity


Summary and conclusions l.jpg
Summary and Conclusions macaques

  • Rigorous definition of macaque NK cells (CD3-CD8+NKG2A+) only achievable by polychromatic flow cytometry

  • NK subsets vary dramatically in different compartments:

  • PB: CD16+

  • LN: CD56+≈DN

  • Mucosal tissues: CD56+>DN

  • Function of NK cell subsets vary significantly

  • CD16+: primarily cytotoxic effectors

  • CD56+: primarily cytokine-secreting cells

  • DN: cytokine secretion and cytotoxic capacity

  • Standard CD16+ definition of NK cells misses > 80% of those in tissues and in lymph nodes

  • CD16hiCD56– and CD 56hiCD16– macaque NK subsets are analogous to human NK cells in phenotype, function and tissue distribution


Objectives12 l.jpg
Objectives macaques

  • To characterize NK cell subsets in blood and tissues of normal rhesus macaques and correlate functionality with discrete cellular phenotypes

  • To examine NK cell function in blood and tissues of macaques infected with wild-type or live attenuated SIV



Slide14 l.jpg

NK cells during HIV/SIV infections macaques

Alter and Altfeld, J Intern Med, 2008


Slide15 l.jpg

SIV infection modulates distribution of NK cell subsets macaques

Viral Load Correlation

R = 0.5494

p = 0.0224


Slide16 l.jpg

SIV infection increases NK cell activation and macaquescytotoxic markers

SIV infection increases activation and cytotoxic capacity


Slide17 l.jpg

SIV perturbs NK trafficking markers macaques

(CD62L)

Mackay, 1999, Nature


Summary and conclusions18 l.jpg
Summary and Conclusions macaques

  • Wild-type SIV infection results in:

  • Expansion of the numbers of circulating CD16+ and DN NK cells

  • Upregulation of activation and cytotoxic markers during SIV infection

  • Downregulation of lymph node trafficking molecules during SIV infection


Slide19 l.jpg

View of earliest transmission events macaques

Rhesus macaque model

Hypothesis

NK cells can interrupt early HIV/SIV replication prior to onset of adaptive responses


Future directions l.jpg
Future Directions macaques

  • Comprehensive phenotypic and functional assessments of NK cells in lymphoid and mucosal tissues:

  • Study groups:

  • Normal, WT SIV- and SIV∆nef-infected macaques

  • Intensive sampling of lymphoid and GALT tissue

  • Assays:

  • Cytoxicity assays vs 721 and SIV-infected cells

  • Viral suppression

  • Intracellular cytokine staining

  • Quantitative RT-PCR of NK receptors

  • Hypotheses to be addressed:

  • Acute SIV infection induces a rapid influx of NK cells to sites of virus replication (i.e., gut mucosa) that precedes virus-specific adaptive immune responses.

  • Acute SIV infection results in activation of NK cells associated with increased cytotoxicity and ability to inhibit SIV replication.

  • NK cell activity is a correlate of control and protection against wild-type and attenuated lentiviruses.


Acknowledgements l.jpg
Acknowledgements macaques

New England Primate Research Center, Harvard Medical School

  • Primate Medicine

  • Angela Carville

  • Pathology

  • Kate Hammerman

Immunology

  • Jackie Gillis

  • Tristan Evans

  • Michelle Connole

  • Fay Eng Wong

  • Yi Yu

  • Paul Johnson

  • Miti Kaur

FUNDING

  • Ragon Institute

  • Galit Alter

  • Marcus Altfeld

  • NCI-Frederick

  • Mike Piatak

  • Jeff Lifson

  • U. Minnesota

  • Ashley Haase

  • SFBR

  • Luis Giavedoni


ad