 Longitudinal analysis of mucosal immune quiescence and impact of commercial sex work in HIV Exposed Seronegative (HESN) sex workers from Nairobi, Kenya Boily-Larouche G., Kirwan S., Lajoie J., Kimani J., Fowke K.R.

A global view of HIV infection 34 million people living with HIV, with Sub-Saharan Africa being the most heavily affected with 72% of new infections. From: WHO/UNAIDS, 2011

HIV infection  HIV preferentially establishes a productive infection in activated CD4+ T cells.  Infection of a small funder population at site of entry that is fuelled by local activation of immune cells.  Acting on the initial inflammation prevent SIV acquisition (Li et al Nature 2009)

Natural correlates of protection  HIV Exposed Seronegative (HESN)  Sub-group of women from the Pumwani CSW cohort in Nairobi, Kenya remain uninfected by HIV-1 despite intense exposure Defined as: HIV PCR & serology neg still active in sex work 7 years or more of follow up remaining uninfected  HESN individuals provide a unique opportunity to study natural correlates of protection against HIV infection

Immune quiescence (IQ)  HESN CSWs harboured immune quiescent phenotype  Systemic IQ  Generalized lower gene expression (McLaren JID 2010)  Lower levels of activated T cells and higher frequency of Treg in the blood (Card JID 2009)  Mucosal IQ  Low levels of chemokines (IP-10 and MIG) and cytokines (Lajoie et al. Mucosal Immunol 2012)  Higher levels of anti-inflammatory proteins (Burgener et al. J Proteome Res )

Immune activation and HIV targets  Immune activation correlates with infection Card CM et al. (2012) PLoS ONE Altered HIV susceptibility : IQ limits the available targets for HIV replication

Impact of Sex Work  Sex derived antigens are powerful immune stimulants  Induced cytokines/chemokines expresionn and immune cells recruitment at the FGT (Sharkey et al. JI 2012)  Triggered peripheral allo-immune response (Peters et al. Lancet 2004)  Interindividual variability in sex-derived antigens response (activation vs tolerance) (Kingsley et al. Plos One 2009)  Sex work  Constant immune pressure  Better control of sex-derived immune activation = Protection  Sex work alters immune activation at the female genital tract, therefore cell susceptibility to HIV.

Pilot Sex Break Study  Pilot Sex Break Study to determine if  Reduced sexual activity impact activation levels of the immune system  Better regulation of activation levels could contribute in protection against HIV acquisition

Pilot Sex Break Study  Designed to characterize immune activation before and immediately following a break from regular sexual activity among sex workers on sabbatical. SE. Kirwan

Impact of Sex Work Controls Continued active sex work Interruption in sex work 7 weeks (mean, 3-16) 1.Determine the impact of sex work on the level of immune systemic and mucosal activation

Regulation of Immune activation in HESNs HESN (>3y) New Negative (< 3 y) HIV positive Interruption in sex work 7 weeks (mean, 3-16) 2. Determine the difference in the regulation of the levels of immune activation upon interruption in sex work and resumption of commercial sexual activity

CD4+ and CD8+ T cells CD38, HLA-DR, CD69, CD107A, CCR5, CD95 Compare the proportion of expressing cells for each marker SE. Kirwan CD4+ T cells CD8+ T cells Phenotyping

Impact of Sex Work CD4+ T cellsCD8+ T cells Vaginal Mucosa : HIV+ P=0.030P=0.016 P=0.0018

Impact of Sex Work CD4+ T cells CD8+ T cells Blood : HIV+ P=0.079 P=0.053 P=0.007 P=0.006 P= Interruption in commercial sexual activity alter the level of immune activation (CCR5, CD95)

Regulation upon sex interruption Vaginal Mucosa : HESN vs New Neg P=0.036 CD8+ T cells P= HESN Interruption in commercial sexual activity is differently regulated between HESN and New Neg New Neg

Regulation following resumption to sex work * Cervical CD69+ CD4+ T cells P= HESN New Neg HIV More targets in the vaginal tract of new negatives following resumption of sex work…

Summary  Interruption in commercial sexual activity affects the levels of immune activation, especially within the HIV-positive CSWs.  Immune activation levels in genital tract of HESNs remain constant even upon return to sex work.  HESNs maintain low level of activation of CD4+ T cells in the genital tract following resumption of sex work. This would mean less target cells at the site of entry.

Acknowledgments  University of Winnipeg  Dr Keith Fowke and lab members  Dr Sheryl Kirwan  Dr Julie Lajoie and Jennifer Juno  Dr Frank Plummer, Dr Blake Ball & Lab Members  University of Nairobi  Dr Joshua Kimani  Dr Makobu Kimani, Charles Wachihi, Catherine Kago & other Majengo Clinic staff  Women of the Majengo Cohort  Funders UNIVERSITY OF MANITOBA UNIVERSITY OF NAIROBI