R5 p 2.9% X4 p

1. CCR5-dependence prevents X4-tropic HIV-1 rebound post CCR5-Δ32-SCT in the “Berlin Patient” Patient viruses and control viruses NheI patient V3-HXB2 ΔV3 HXB2 Patient V3 BmgBI Jori Symons1, Steven Deeks2, Gero Hütter3, Annemarie Wensing1, Jeff Martin2, Petra van Ham1, Linos Vandekerckhove4, Monique Nijhuis1 R5-predicted X4-predicted 1 Department of Virology, Medical Microbiology, University Medical Center Utrecht, the Netherlands. 2 Department of Medicine, University of California, San Francisco, California, USA. 3 Institute of Transfusion Medicine and Immunology, Heidelberg University, Germany. 4 Department of Internal Medicine, Infectious Diseases and Psychosomatic Medicine, Ghent University Hospital, Ghent, Belgium. cbal, R5-predicted patient derived variant cHXB2, X4-predicted patient derived variants Co-receptor usage in cell lines Infectivitytested in PBMCswith co-receptor inhibitors Infectivitytested in patientderived post-SCT PBMCs Introduction, Objective and Methods Why is there no X4 virus rebound observed? R5p 2.9% X4p X4p?

2. Genotypic vs Phenotypic results X4-predicted variants CCR5 dependence R5, X1-X5 replication competent X4-predicted variants inhibited by MVC R5-phenotype X4-predicted variants unable to infect post- SCT CCR5-Δ32/Δ32 cells

3. Evolution Results + p24 + p24 + p24 100/0 70/30 40/60 10/90 + p24 + p24 U373-MAGI-CCR5E U373-MAGICXCR4CEM MT-2 MT-2 Hütter et al., N Engl J Med, 2009. Allers. et al., Blood, 2011 Proviral-DNA  remaining reservoir CCR5 expressing macrophages  target cells • Conclusion • The X4-predicted variants are fully dependent on CCR5 for replication. • No co-receptor switch was observed, suggesting a relatively high genetic barrier towards CXCR4-usage. • In the target cell selection assay no co-receptor switch was observed.