Center for Biomedical Research HSV-2 infection of dendritic cells amplifies a highly susceptible HIV-1 cell target: implications for mucosal transmission Elena Martinelli Center for Biomedical Research Population Council © [2011] The Population Council, Inc.

HSV-2 infection increases the risk of HIV-1 acquisition ★ HIV-1 targets persist at the site of HSV-2 reactivation in absence of HSV-2 replication ★ Co-infection HIV/HSV-2 is associated with reduced HIV-specific response and immune activation ★ Macaque HSV-2-infected DCs stimulate weaker SIV-specific responses than uninfected in-vitro A macaque model to study vaginal HSV-2/immunodeficiency virus co-infection and the impact of HSV-2 on microbicide efficacy Crostarosa et al November 2009 Vol. 4 No 11

Which host-related factors are associated with higher susceptibility to HIV/SIV mucosal infection?

NHP Model of Rectal HSV-2 infection LIVE vs UV-inactivated HSV-2 Rectal Swabs Necropsy DAYS 3 6 ★ HSV-2 shedding in 9 of 11 animals challenged with live HSV-2 ★ No HSV-2 shedding in UV- HSV-2 treated animals (n=8)

Potential Role of α4β7high CD4+ T cells MEM CD3 CD95

HIV/SIV and α4β7 reduces SIV load and pro-viral DNA ★ 47 is essential for cell homing to the gut and co-localizes with CD4 and CCR5 on T cells and ★ gp120 binds 47 via the LDV motif of the V2 loop (early-transmitted has higher reactivity for α4β7) ★ 47high CD4+ T cells are preferentially infected ★ In vivo blockade of α4β7: reduces SIV load and pro-viral DNA preserves blood and gut CD4+ T cell dampens pDC recruitment to the colorectum, reducing immune activation

Increased frequency of α4β7high CD4+ T cells in HSV-2 infected animals Blood Rectum LNs ** ** * ** ** ** ** ** ** ** ** % α4β7high % α4β7high % α4β7high % α4β7high % α4β7 BL LIVE UV LIVE UV AX M ING ILIAC LIVE UV

HSV-2-infected DCs up-regulate α4β7 on CD4+ T cells *** % α4β7high (Fold) HSV moDC CD4+ T α4β7 CCR5 MOCK UV LIVE T ONLY CD4 CD4+ T

HSV-2 infected DCs enhance HIV replication in the DC-T milieu *** *** moDC HIV-1 /cell (Fold) HIV α4β7 CCR5 MOCK UV LIVE CD4 CD4+ T

Memory α4β7high CD4+ T cells: % of CD95+ that are α4β7high HIGH CD4 α4β7 MEM CD3 CD95

Frequency of memory α4β7high CD4+ T cells in blood appears to correlate with SIV acquisition DAY 0 DAY 3 DAY 10 POS at DAY 14 POS = positive by SIVgag PCR at DAY 10

Summary ★ Rectal HSV-2 infection of increases the frequency of 47high CD4+ T cells locally and systemically ★ HSV-2-infected DCs up-regulate 47 on CD4+ T cells and increase HIV replication in the DC-T milieu ★ Macaques with higher frequency of 47high CD4+ T cells in blood appear more susceptible to SIV rectal infection

Acknowledgements Melissa Robbiani Center for Biomedical Research Population Council Melissa Robbiani Meropi Aravantinou Nina Derby Ines Frank Joselin Galvez Mayla Hsu Edith Jasny Jessica Kenney Pavel Pugach Hugo Tharinger Filippo Veglia Loreley Villamide-Herrera Aaron Diamond AIDS Research Center Agegnehu Gettie Tulane National Primate Research Center James Blanchard Laboratory of Immunoregulation, NIAID James Arthos AIDS and Cancer Virus Program, NCI-Frederick Jeffrey D Lifson Michael Piatak Jr Julian Bess This work was supported by NIH grant R37 AI040877