Role of Adaptive vs. Innate Immune Activation in non-AIDS Morbidity Peter W. Hunt, MD Associate Professor of Medicine UCSF HIV/AIDS Division

A shift in focus… T cell activation as a target for interventions in the pre-ART era Monocyte activation and inflammation a target during treated HIV disease Why this shift is occurring –Important caveats Implications for future clinical trials

Pneumocystis carinii pneumonia and mucosal candidiasis in previously healthy homosexual men: evidence of a new acquired cellular immunodeficiency MS Gottlieb, R Schroff, HM Schanker, JD Weisman, PT Fan, RA Wolf, and A Saxon Dec 10, 1981 T10=CD38 Leu3=CD4

CD8+ T cell activation predicts survival better than VL in patients with AIDS (CD4<200) Janice Giorgi Giorgi, JID, 1999 (see also: Giorgi, JAIDS, 2002) Survival P=0.02 Survival P=0.001

T Cell Activation Declines with ART Hunt et al, JID, 2003; PLoS One, 2011

But Remains Abnormally High During ART-mediated Viral Suppresion Hunt et al, JID, 2003; PLoS One, 2011

Is T cell activation a cause of disease in treated HIV infection or simply a marker for some other process? Important for identifying targets for novel interventions

Low CD4 Count during ART Predicts non-AIDS Death Young et al for COHERE cohort, PLoS Med, 2012 (see also Baker, AIDS, 2008)

IL-2 Increases CD4 Counts in Treated Patients Abrams et al, NEJM, 2009 IL-2 also decreases HLA-DR and CD38 expression (Kovacs, NEJM, 1995)

However, IL-2 Had No Effect on AIDS/Death Abrams et al, NEJM, 2009 P=0.47 P=0.55 CD4 count (and CD38 / DR expression) is not 100% specific for the pathophysiologic pathway mediating disease.

Why didn’t IL-2 work? May have expanded the wrong type of CD4+ T cells (regulatory cells). –Impaired functional immune responses? Could CD4+ T cell count just be a marker for some other immunologic process?

What Specific Immunologic Pathways are Driving Disease during ART? Non-AIDS Morbidity / Mortality Innate Immune Activation (MØ/DC) CD4 Lymphopenia Inflammation T and B Cell Activation/ Dysfunction ? ? ? Coagulation ?

What Specific Immunologic Pathways are Driving Disease during ART? Non-AIDS Morbidity / Mortality Innate Immune Activation (MØ/DC) CD4 Lymphopenia Inflammation T and B Cell Activation/ Dysfunction ? ? ? Coagulation ?

Hunt et al, JID, 2003 (see also Goicoechea, JID, 2006; Gandhi, JAIDS, 2006) High T Cell Activation Associated with Blunted CD4 Recovery during ART

Lederman et al., JID, 2011 Inflammation and Innate Immune Activation are Increased in Patients with Poor CD4+ T cell Recovery on ART IL-6 sCD14 CD4<350 CD4>500 HIV- CD4<350 CD4>500 HIV-

How do we get a better sense of the specific immunlogic pathways driving disease?

Eden et al., JID, 2007 (see also: Burdo, AIDS, 2013; Lyons, JAIDS, 2011; Letendre, CROI 2012, Abstract #82) Abnormal CSF Neopterin Levels Persist Despite 4 Years of VL Suppression 60% Abnormal

Sinclair, JAIDS, 2008 CD8+ T Cell Activation is Not Persistently Elevated in CSF During Suppressive ART T cell activation in the CNS is unlikely to explain persistent neurocognitive dysfunction in ART-suppressed individuals

Baker, CROI 2013, Abstract #66LB Monocyte Activation Predicts Coronary Artery Calcium Progression: SUN Study T cell Activation Not Predictive

Do these markers predict clinical events?

SMART: Inflammatory Markers Strongly Associated with Mortality and CVD Events Biomarker All-Cause Mortality (N=85) Fatal or Non-fatal CVD (N=136) ORP-valueORP-value hs-CRP IL-612.4< Amyloid A Amyloid P D-dimer41.2< F Kuller L et al. PLoS Med, 2008; Duprez, Atherosclerosis, 2009 Even after adjusting for CD4 count!

Hunt, CROI 2012, Abstr #278 (see also : Tenorio, CROI 2013, Abstr# 790) Innate Immune Activation Predicts Mortality More Strongly than T Cell Activation: SOCA Gut Epithelial Barrier Dysfunction Inflammation / Coagulation Matched for age, gender, duration VL suppression, CMV retinitis, nadir CD4 IDO-1 Induction Monocyte Activation

Hunt, CROI 2012, Abstr #278 (see also : Tenorio, CROI 2013, Abstr# 790) Innate Markers Predict Mortality Independent of Nadir AND Current CD4 count Gut Epithelial Barrier Dysfunction Inflammation / Coagulation Also adjusted for current CD4 count IDO-1 Induction Monocyte Activation Current CD4 count no longer predictive of mortality after adjusting for innate markers

Why does T cell “senescence” not predict mortality in HIV infection?

Lee, CROI 2013, #294

HIV Disease Drives Expansion of CD28- CD8+ T Cells... All CMV+ Lee, CROI 2013, #309 P= P=0.10

But CD57 is inappropriately low on CD28- CD8+ T Cells in HIV infection All CMV+ Lee, CROI 2013, #309 P< P=0.0003

Low (Not High) CD57 on CD28- CD8+ T Cells Predicts Mortality in Treated HIV *Subjects matched on age, gender, duration of viral suppression, presence of CMV retinitis, and nadir CD4+ cell count Lee, CROI 2013, #309

Higher Monocyte Activation Associated with the Low CD57 CD8+ T cell Defect Lee, CROI 2013, #309 Monocyte activation may cause T cell proliferative defects in HIV by: PD1-driven IL-10 release (Said, Nat Med, 2010) IDO-1 induction (Boasso, Blood, 2007)

What Specific Immunologic Pathways are Driving Disease during ART? Non-AIDS Morbidity / Mortality Innate Immune Activation (MØ/DC) CD4 Lymphopenia Inflammation T and B Cell Activation/ Dysfunction ? ? Coagulation

Caveats…

T / B Cell Activation Predicts NHL (MACS) Breen, Cancer Epi Bio, 2011 Adjusted for age, duration HIV infection, and CD4 count

T Cell Activation may be an important contributor to HIV reservoir size… Hatano, JID, 2013

Implications for Clinical Trials

CD8 Activation is a Reproducible and Responsive Marker Hunt, Blood, 2013 Placebo Arm Std Dev of ∆ Wk 0-24: 0.13 log 10 % ~35% relative change

Lots of Within-subject Variability in IL-6 Std Dev of ∆ Wk 0-24: 0.38 log 10 pg/ml ~2.4-fold relative change Hunt, Blood, 2013

sCD14 is much better, comparable variability to T cell activation Std Dev of ∆ Wk 0-24: 0.11 log 10 ug/ml ~29% relative change Hunt, Blood, 2013

Several immunologic defects predict disease in treated HIV infection: –Innate immune activation and inflammation –CD4 lymphopenia –T cell / B bell activation and dysfunction Innate immune activation and inflammation independently predict disease, less consistent for other markers. Interventions designed to decrease activation of myeloid lineage cells may hold promise. –Statins, ASA? –Microbial Translocation interventions –Treating co-infections? Summary

Acknowledgements NIAID Jason Brenchley Danny Douek Irini Sereti Core Immunology Lab/DEM Elizabeth Sinclair Lorrie Epling Mike McCune SOCA Curtis Meinert Mark Van Natta ACTG Heather Ribaudo SCOPE/OPTIONS/UCSF Sulggi Lee Steve Deeks Jeff Martin Hiroyu Hatano Vivek Jain Rebecca Hoh Rick Hecht CWRU Wei Jiang Michael Lederman Nick Funderburg Brian Claggett U Minnesota Jason Baker R56AI100765, 1R21AI087035, 1R21AI07877, DDCF CSDA