Rapid perforin upregulation directly ex vivo by CD8 + T cells is a defining characteristic of HIV elite controllers

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1 Rapid perforin upregulation directly ex vivo by CD8 + T cells is a defining characteristic of HIV elite controllers Adam R. Hersperger Department of Microbiology University of Pennsylvania

2 Evidence for a protective role by HIV specific CD8 + T cells Depletion of CD8 + T cells during SIV infection leads to increased viral load Jin, et al. JEM 1999; Schmitz, et al. Science Viral load can be contained in the presence of certain MHC class I haplotypes (e.g. HLA B27 and HLA B57) Migueles, et al. PNAS 2000; Goulder, et al. Nat. Med Temporal correlation between resolution of acute viremia and appearance of HIV specific CD8 + T cells Koup, et al. JV 1994; Borrow, et al. JV Selective pressure by CD8 + T cells leads to escape mutation Goulder, et al. Nat. Med. 1997; Borrow, et al. Nat. Med. 1997; Price, et al. PNAS 1997.

3 Human CD8 + T cells can rapidly upregulate perforin Perforin mrna can be upregulated with the same kinetics as cytokines Detectable in a standard 6 hour ICS assay without addition of exogenous cytokines or proliferation Newly produced perforin traffics directly to the immunological synapse largely bypassing cytotoxic granules Involved in the sustained lysis of target cells References: 1. Makedonas, et al. Journal of Immunology Hersperger, et al. Cytometry Part A

4 What is the role of rapid perforin expression by CD8 + T cells in the setting of HIV infection?

5 HIV infected patient cohort 10 8 Plasma Viral Load (copies/ml) weeks Viremic Nonprogressors (n=6) Chronic Progressors (n=24) Viremic Controllers (n=29) years Elite LTNP/Controllers (n=34) Majority of subjects were treatment naïve EC and VC had viral load within set range for a minimum of three determinations of plasma HIV RNA spanning at least a 12 month period CD4 + T cell counts not considered for inclusion criteria, except for the VNP group

6 Approach to assess HIV specific CD8 + T cell responses by polychromatic flow cytometry Stimulate cells with overlapping peptide pools encompassing the entire HIV (clade B) proteome: Gag, Pol, Env, Nef, TRVVV Incubate for 6 hours in presence of anti CD107a mab Surface stain cells for viability, lineage, and memory markers Stain cells for functional parameters (64 combinations): IFN γ IL 2 MIP1α TNFα Perforin Perforin (B-D48 clone) IFN-γ

7 The magnitude of the HIV specific CD8 + T cell response does not vary widely between groups

8 Differences in degranulation, cytokine expression, and chemokine production between groups

9 Perforin expression in polyfunctional CD8 + T cells

10 Poorly functional HIV specific CD8 + cells produce the majority of perforin

11 Monofunctional cells may also be important Five functions: Five functions plus perforin:

12 Perforin expression is independent of infection duration, progression status, or rate of CD4 + T cell decline

13 No association between protective HLA B alleles and perforin expression One way ANOVA followed by Dunn s multiple comparison test

14 Inverse correlation between HIV specific CD8 + T cell perforin expression and viral load Spearman correlation test

15 Conclusions Elite controllers have an increased capacity to express and rapidly upregulate perforin compared to patients who have detectable viremia This higher perforin expression is observed to all HIV antigens There is a strong inverse correlation between perforin expression and viral load No association between the presence of known protective HLA B alleles and perforin expression Perforin expression is not restored by HAART Majority of perforin is expressed in effector cells (CD27 neg CD45RO neg CD57±) These findings may be useful in the HIV vaccine field as a marker for an effective CD8 + T cell response

16 Acknowledgements Betts Lab (UPenn) Michael Betts George Makedonas Korey Demers Jay Gardner UPenn CFAR Ian Frank Debbie Gudonis Special thanks to the International HIV Controllers Study for providing a patient sample network and the patients themselves. Walker Lab (Harvard) Bruce Walker Florencia Pereyra Kaul Lab (Toronto) Rupert Kaul Prameet Sheth Lucy Shin Lederman Lab (Case Western) Michael Lederman Benigno Rodriguez Scott Sieg Leia Teixeira Johnson Goepfert Lab (UAB) Paul Goepfert FUNDING: NIAID R01 AI076066

17 What T cell response parameters could be important for the control of HIV replication? Frequency Specificity Clonotype Pattern of cytokine expression Avidity ( antigen sensitivity ) Phenotype Homing capability Effector capability such as perforin expression

18 Enhanced perforin expression is displayed in elite controllers across all HIV antigens

19 Elite controllers also display better perforin expression than progressors after CEF peptide stimulation

20 HIV specific perforin expression is not restored by short term HAART

21 Perforin expressing CD8 + T cells are effectors