The Potential of Attenuated Mycobacterium tuberculosis or BCG Vaccines to Enhance Oral SIV Acquisition in Infant Macaques IAS Meeting-Vancouver July 22, 2015 Kristina De Paris, PhD UNC Chapel Hill No Disclosures

Prevention of Mother-To-Child-Transmission of HIV-1 Infection rate: 3% of children / year Median age: mo. HIV-TB co-infection: 30-50% + Tuberculosis BCG - administration at birth (PO / ID) - immunogenic - risk of dissemination in HIV + infants Breast milk transmission of HIV-1

An auxotroph mutant of human-adapted M. tuberculosis H37Rv (i)is attenuated for replication and pathogenicity,  can be manipulated for increased immunogenicity, and  modified to express HIV antigens. Pediatric HIV-TB Combination Vaccine Auxotroph rMtb-HIV vaccines, administered at birth, may present a safe alternative to BCG that could protect against oral HIV-1 acquisition and TB infections. mc : ΔleuCDΔpanCDΔsecA2:pSIV Gag/pSIV Env/pSIV Pol Jensen et al., 2012 and 2013

Repeated Low-Dose Oral Challenge Model (SIVmac251) - recapitulate repeated exposure to HIV-1 in breast-feeding infants - start at 9 weeks of age Probability of infection / exposure = n=15 Vaccine Efficacy: sterilizing immunity or partial efficacy (No. of SIV exposures)

Challenge Outcome in Vaccinated Infant Macaques rMtb-SIV/ rMtb-SIVrMtb-SIV/ MVA-SIV - rMtb-SIV at birth (PO) - homologous boost (ID): wk. 3 - single rMtb-SIV at birth (PO) - heterologous boost (IM): wks /67/8 Vaccine-induced Enhancement of Infection?!

Independent of:strain, route, boost, and SIV inserts. Probability of infection / exposure: Mtb vaccines BCG0.353 Mtb Vaccine 15/19 Repeat and Confirm: BCG (ID) 6/7

Oral SIV Acquisition Biological Significance 1.4-fold risk enhancement NS STAT Trivia: To detect a 1.65-fold higher risk with 80% power, 45 animals/group are required.

Oral SIV Acquisition Risk - enhanced infection risk in two separate studies …and increased peak viremia (BCG) Peak Viremia

Systemic Immune Activation (TOC) 37-plex (NHP) - only 4 differ! sCD14sCD163 MCP-1

Increased Monocyte Activation + Function Target cells of mycobacteria: monocytes/ macrophages and DC CCR5CD69 Blood and Tissues Persistence up to 18 wks.! PBMC Ax.LNSubm.LN Tonsil TNF- 

Vaccine-induced CD4 + T Cell Activation Increased SIV target cells at TOC?! ( Ki67, CD69, PD-1 ) CCR5 + CD4 + T Potential Viral Entry Sites (16-18 wks.) ColonRetrophar.LN Ki-67 PBMC

Summary Mtb- and BCG-based vaccines  cause persistent immune activation of myeloid cells (monocytes/ mDC),  increase the numbers of potential SIV/HIV target cells, and thereby  may enhance risk of oral SIV/HIV acquisition, and  alter challenge outcome as immune activation persists even post-challenge.  Enhanced risk of oral SIV infection was not associated with genetic markers.

 BCG-induced “trained immunity” (Netea) - epigenetic changes in monocytes enhance functional capacity - increased responsiveness to mycobacterial and unrelated Ags for up to 1 yr! Supporting Evidence from HUMAN Studies consistent with the persistent increased functional capacity of monocytes and mDC in vaccinated infant macaques  BCG – risk factor for HIV? - BCG vaccination in SA infants results in increased CCR5+CD4+T cells (Jaspan) - Mtb-exposed CD4 + T cells show increased HIV-1 infection in vitro (Page) consistent with increased CD4 + T cell activation in blood and tissues of infant macaques vaccinated with Mtb or BCG vaccines

Potential Health Impact  TB vaccine development: - auxotroph BCG and auxotroph Mtb strains, similar to our strain - combination HIV-BCG vaccines are being tested (Hanke, Joseph, Williamson) Protective efficacy against TB infection  BUT: Safety risk for pediatric population? - increased susceptibility to oral HIV-1 infection - increased morbidity due to higher viremia and persistent immune activation - include testing for immune activation in TB vaccine safety assessment

THANK YOU to: Kara Jensen Myra dela Pena Maggie Conner Michael Mengual Neelima Choudhary Michael Hudgens Katie Mollan CNPRC Koen Van Rompay Veterinary Staff rMtb Vaccine Michelle Larsen Glenn Fennelly Bill Jacobs Uma Ranangathan Virology Mike Piatak Jeff Lifson Pam Kozlowski Robert Wilson Angela Amedee LSUHSC NIH: R01 DE and R01 DE S1 to ML, GF, and KDP De Paris Lab Histology Jake Estes Carissa Lucero NIH HIV/ AIDS and TB Program Officers