1. 2014 “Towards an HIV Cure” symposium Melbourne SIV infection of the macaque testis – an immune privileged site Wendy Winnall, University of Melbourne

2. ? HIV persistence in the testis? Does HIV persist in the testis? Why should we care? Transmission through seminal plasma? Reservoir during cART?

3. Is the testis a sanctuary for HIV? Possible mechanisms for HIV persistence in the testis: Blood testis barrier? Testicular immune privilege? ?

4. Cells of the testis Lumen blood vessel Seminiferous tubuleInterstitium lymphatic vessel

5. Cells of the testis Lumen blood vessel Seminiferous tubuleInterstitium lymphatic vessel Spermatocytes Spermatogonia Spermatids

6. Cells of the testis Lumen blood vessel Seminiferous tubuleInterstitium lymphatic vessel Sertoli cells

7. Cells of the testis Lumen blood vessel Seminiferous tubuleInterstitium lymphatic vessel Sertoli cells Blood-testis barrier Pgp

8. Cells of the testis Lumen blood vessel Seminiferous tubuleInterstitium lymphatic vessel Leydig cells Sertoli cells Leukocytes: macrophages T cells Blood-testis barrier Pgp

9. Is the testis a sanctuary for HIV? Possible mechanisms for HIV persistence in the testis: Blood testis barrier? Testicular immune privilege? ?

10. ? Is the testis a sanctuary for HIV? Possible mechanisms for HIV persistence in the testis: Blood testis barrier? Testicular immune privilege? Suppression of innate and acquired immune responses in the testis of rodents Predicted to protect immunogenic spermatids from immune responses and inflammation

11. Pigtailed macaque model for HIV infection SIV infects the pigtailed macaque testis Shehu-Xhilaga et al Retrovirology, 2007

12. Aims Are immune responses suppressed in the macaque testis? How does SIV infection affect the testis? Do testicular CD8 T cells respond to SIV infection?

13. SIV infection of pigtailed macaques Testes and blood taken from: 7 uninfected macaques 4 macaques infected with SIV mac239 10 weeks 24 to 30 weeks

14. Is there immunosuppression in the macaque testis? unstimulated mitogen stimulation

15. Is there immunosuppression in the macaque testis? unstimulated mitogen stimulation T cell responses in the testis are lower than in the blood Wilcoxon Signed Rank test

16. Aims Are immune responses suppressed in the macaque testis? How does SIV infection affect the testis? Do testicular CD8 T cells respond to SIV infection?

17. SIV damages the macaques testis uninfected SIV week 10

18. SIV alters testis leukocyte populations uninfected testis CD3+ SIV week 10 CD3+

19. SIV alters testis leukocyte populations uninfected testis CD3+ SIV week 10 CD3+ blood testis blood testis

20. SIV alters testis leukocyte populations uninfected testis CD3+ SIV week 10 CD3+ blood testis blood testis SIV infection lead to: Loss of CD4 T cells Influx of CD8 T cells Shift towards effector memory and away from central memory

21. Aims Are immune responses suppressed in the macaque testis? How does SIV infection affect the testis? Do testicular CD8 T cells respond to SIV infection?

22. Are there CD8 T cell responses in the SIV-infected testis? uninfected testis CD8+ SIV week 10 CD8+ KP9-ManeA*084 tetramer

23. Are there CD8 T cell responses in the SIV-infected testis? uninfected testis CD8+ SIV week 10 CD8+ SIV-specific CD8 T cells in testis and blood KP9-ManeA*084 tetramer SIV-specific CD8 T cells were detected in the testis blood testis

24. SIV inhibits CD8 T cell cytokine production SIV wk 10 testis CD8+ SIV wk 10 blood CD8+

25. SIV inhibits CD8 T cell cytokine production blood testis SIV infection inhibited cytokine production by CD8 T cells in response to mitogens SIV wk 10 testis CD8+ SIV wk 10 blood CD8+ Cytokine production after mitogen stimulation

26. Summary T cell responses to mitogens are relatively low in the macaque testis Evidence for immune privilege in the primate testis SIV infection affects the macaque testis: Damage to the testis architecture Influx of effector memory CD8 T cells Loss of CD4 T cells

27. Summary SIV-specific CD8 T cells were detected in the testis However cytokine production in response to mitogens was inhibited by SIV infection Immunosuppression in the macaque testis reduces the ability of CD8 T cells to respond to infection, making the testis vulnerable to persistent SIV infection and damage. Testicular immune privilege

28. Acknowledgements Kent Lab, Doherty Institute University of Melbourne Stephen Kent Rob De Rose Sarah Lloyd Vinca Alcantara Thakshila Amarasena Marit Kramski Shayarana Gooneratne Hyon-Xhi Tan Monash University Mark Hedger Dept of Obstetrics and Gynaecology, University of Melbourne Jane Girling CSIRO AAHL Geelong Megan Schepers Lisa Reid