1. Adj. Assistant Professor, UCLA Department of Medicine
HIV Cure Research Updates
Dr. Matthew Marsden
Adj. Assistant Professor, UCLA Department of Medicine
9/3/14

3. Why is HIV difficult to cure?
Documented cases of apparent cures
New gene therapy/transplant approaches
Additional therapeutic approaches

4. HIV persistence during therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)

5. HIV persistence during therapy
Antiretroviral therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)

6. HIV persistence during therapy
Short-lived infected cell
Long-lived infected cell
(latently infected)

7. Lerner et al. J Virology 2011: Patient undergoing STI
Alexander et al. JAIDS 2003
Patient undergoing multiple STI

8. Untreated HIV infection
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle

9. Prevents disease progression but no cure (rare infected cells persist)
Untreated HIV infection
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
Treated with optimal antiretroviral therapy
Prevents disease progression but no cure
(rare infected cells persist)

10. Prevents disease progression but no cure (rare infected cells persist)
Untreated HIV infection
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
Treated with optimal antiretroviral therapy
Latently infected CD4+ T lymphocytes are rare in vivo:
Approximately 1 per 106 total resting CD4+ T cells
Probably constitute around cells per patient
Prevents disease progression but no cure
(rare infected cells persist)

11. Marsden & Zack: Bioorg Med Chem Lett. 2013 Jul 15;23(14):4003-10. 

12. Marsden & Zack, Bioorg Med Chem Lett. 2013

13. Approximately 1 per million resting CD4+ T cells harbor a latent provirus.
Rose Bowl Capacity = 92,542

14. Approximately 1 per million resting CD4+ T cells harbor a latent provirus.
Rose Bowl Capacity = 92,542
Like finding one person in 11 football stadiums.
To cure the infection we need to do this with 1,000,000 (one million) cells hidden in this way.

15. Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells

16. Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells
Ablative therapy (destroys immune system)
Followed by transplant with HIV-resistant cells
Might allow cure of infection
(elimination of all replication-competent virus)

17. Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells
Ablative therapy (destroys immune system)
Followed by transplant with HIV-resistant cells X
Might allow cure of infection
(elimination of all replication-competent virus)

18. The “Berlin Patient”

19. HIV enters cells by binding to CD4 and a “corecepter” (often CCR5).
CCR5 is not functional in approximately 1% of Caucasians, which means they are highly resistant (but not completely immune) to infection with most strains of HIV.
This mutation is called CCR532.

20. The “Berlin Patient” was HIV positive and also developed leukemia.
He underwent aggressive chemotherapy to clear the leukemia, and in the process almost all the HIV+ cells in his body were also killed.
This patient then received two bone marrow transplants from a CCR5-32 individual.
The new immune cells were not susceptible HIV, and the virus in currently undetectable more than seven years post-transplant.

21. Cells of the Immune System
Macrophage
Mast cell
Eosinophil
Erythrocytes
Marrow
Marrow
Basophil
Monocyte
Megakaryocyte
Bone
Hematopoietic stem cell
Multipotential
stem cell
Myeloid progenitor cell
Neutrophil
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from :

22. Cells of the Immune System
Macrophage
Mast cell
Eosinophil
Erythrocytes
Marrow
Basophil
Monocyte
Megakaryocyte
Bone
Hematopoietic stem cell
Multipotential
stem cell
Myeloid progenitor cell
Neutrophil
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from :

23. Cells of the Immune System
Macrophage
Mast cell
Eosinophil
Erythrocytes
Marrow
Basophil
Monocyte
Megakaryocyte
Bone
Hematopoietic stem cell
Multipotential
stem cell
Myeloid progenitor cell
Neutrophil
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from :

24. Cells of the Immune System
Macrophage
Mast cell
Eosinophil
Erythrocytes
Marrow
Basophil
Monocyte
Megakaryocyte
Bone
Hematopoietic stem cell
Multipotential
stem cell
Myeloid progenitor cell
Neutrophil
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from :

25. Cells of the Immune System
Macrophage
Mast cell
Eosinophil
Erythrocytes
Marrow
Basophil
Monocyte
Megakaryocyte
Bone
Hematopoietic stem cell
Multipotential
stem cell
CCR5-32
Myeloid progenitor cell
Neutrophil
Platelets
Lymphoid progenitor cell
T lymphocyte
Dendritic cell
CD4+ T cell
CD8+ T cell
B lymphocyte
Natural killer cell
Modified from :

26. Figure 1. Timeline for clinical treatments and study samples.
Yukl SA, Boritz E, Busch M, Bentsen C, et al. (2013) Challenges in Detecting HIV Persistence during Potentially Curative Interventions: A Study of the Berlin Patient. PLoS Pathog 9(5): e doi: /journal.ppat

27. Table 4. Summary of virologic measures.
Yukl SA, Boritz E, Busch M, Bentsen C, et al. (2013) Challenges in Detecting HIV Persistence during Potentially Curative Interventions: A Study of the Berlin Patient. PLoS Pathog 9(5): e doi: /journal.ppat

28. Why can’t we use this approach for everybody?
The chemotherapy and bone marrow transplant procedure was very risky (the patient nearly died).
Matching donors that are also CCR5-32 are very hard to find.
The procedure is very expensive, time consuming, and requires excellent medical facilities (not feasible in many parts of the world) .
The patient will have to take immunosuppressive drugs for the rest of their life to avoid problems with the transplant (this may be worse than just taking the anti-HIV drugs).

29. The “Boston Patients”
Dr. Timothy Henrich of Brigham and Women's Hospital

30. Bone marrow transplant with unprotected (not HIV-resistant)
donor cells “the 2 Boston Patients” delayed viral rebound…..
But did not prevent it...

31. The “Boston Patients” were HIV positive and also developed leukemia.
They underwent reduced-intensity chemotherapy to clear the leukemia (stayed on antiretroviral therapy during this process).
They then received a bone marrow transplants (not HIV-resistant cells).
Stayed on ART for 2.6 and 4.3 years and virus was not detectable.
Upon treatment interruption, viral rebound occurred after 3 and 8 months.

32. Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells

33. Delayed virus rebound after stopping therapy but did not prevent it
Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells
Conditioning therapy (destroys most immune cells)
Followed by transplant with non-HIV resistant cells
Delayed virus rebound after stopping
therapy but did not prevent it

34. The “Mississippi baby”

35. Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Infection in the Child.
Persaud D et al. N Engl J Med 2013;369:
“An infant was born by spontaneous vaginal delivery at 35 weeks of gestation to a woman who had received no prenatal care. Rapid HIV-1 testing in the mother was positive during labor. Delivery occurred before antiretroviral prophylaxis was administered. Maternal HIV-1 infection was confirmed by means of Western blot testing.” 
“ART was initiated in the infant at 30 hours of age. A three-drug regimen of zidovudine (at a dose of 2 mg per kilogram of body weight every 6 hours), lamivudine (at a dose of 4 mg per kilogram twice daily), and nevirapine (at a dose of 2 mg per kilogram twice daily) was selected to provide prophylaxis for high-risk HIV-1 exposure and to minimize the likelihood of generating resistant viral variants in the event that the infant had been infected in utero.”

36. Persaud D et al. N Engl J Med 2013;369:1828-1835.
Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Infection in the Child.
Persaud D et al. N Engl J Med 2013;369:
Figure 1. Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Infection in the Child. Panel A shows HIV-1 RNA levels indicating confirmed HIV-1 infection, with positive values for HIV-1 RNA in plasma at four time points before and after the initiation of antiretroviral therapy (ART). The decline in the viral load was biphasic, which is typically seen during effective ART. Panel B shows HIV-1 RNA levels indicating sustained control of HIV-1 replication during ART and after the discontinuation of therapy. The solid arrow indicates the last time that prescriptions for ART were filled (at 15 months of age, according to pharmacy records), and the dashed arrow the time of the last administration of ART (at 18 months of age, according to maternal report). In both Panel A and Panel B, solid circles indicate detectable HIV-1 RNA, and open circles undetectable HIV-1 RNA; the shaded area indicates the limit of detection of the plasma viral-load assay. Panel C shows the percentage of CD4+ T cells from the child's birth until 30 months of age. The shaded area indicates the CD4+ T-cell percentage in the normal range (10th to 90th percentiles); fluctuations in the normal range are due to age-related changes.6 3TC denotes lamivudine, AZT zidovudine, and NVP nevirapine.
Solid arrow = Last prescription for ART filled
Dashed arrow = Time of last ART administration

37.
The “LA Baby” has a similar story to the “Mississippi baby”, but has yet to undergo ART treatment interruption.
“The girl was delivered at Miller Children's Hospital in Long Beach, California, last summer to a mother with HIV who had not received antiretroviral drugs during pregnancy. Doctors gave the baby high doses of three drugs -- AZT, 3TC and Nevirapine -- four hours after birth. Eleven days later, the virus was undetectable in her body and remained undetectable eight months later.”

38. Untreated HIV infection in newborn- Limited reservoir cells?
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle

39. Untreated HIV infection in newborn- Limited reservoir cells?
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
Early treatment with potent antiretroviral therapy
Still under investigation- Perhaps the early treatment
reduced latent reservoir size

40. The “VISCONTI cohort” “Functional cure” for some patients?
Viro-Immunologic Sustained COntrol after Treatment Interruption
“Functional cure” for some patients?

41. “we have observed that some HIV-infected patients interrupting a prolonged antiretroviral therapy initiated close to primary infection are able to control viremia afterwards. We present here 14 of such post-treatment controllers.” 
“Finally, we estimated the probability of maintaining viral control at 24 months post-early treatment interruption to be ~15%, which is much higher than the one expected for spontaneous control.”
Sáez-Cirión A, Bacchus C, Hocqueloux L, Avettand-Fenoel V, et al. (2013) Post-Treatment HIV-1 Controllers with a Long-Term Virological Remission after the Interruption of Early Initiated Antiretroviral Therapy ANRS VISCONTI Study. PLoS Pathog 9(3): e doi: /journal.ppat

42. Table 1. Characteristics of PTC included in the study.
Sáez-Cirión A, Bacchus C, Hocqueloux L, Avettand-Fenoel V, et al. (2013) Post-Treatment HIV-1 Controllers with a Long-Term Virological Remission after the Interruption of Early Initiated Antiretroviral Therapy ANRS VISCONTI Study. PLoS Pathog 9(3): e doi: /journal.ppat

43. The immune response during acute HIV-1 infection: clues for vaccine development
Andrew J. McMichael, Persephone Borrow, Georgia D. Tomaras, Nilu Goonetilleke & Barton F. Haynes
Nature Reviews Immunology 10, 11-23 (January 2010)

44. Periods where patients received therapy
Figure 1. Long-term control of viremia and stable CD4+ T cell counts in fourteen patients after interruption of antiretroviral treatment initiated in primary HIV-1 infection.
Grey Shading =
Periods where patients received therapy
Sáez-Cirión A, Bacchus C, Hocqueloux L, Avettand-Fenoel V, et al. (2013) Post-Treatment HIV-1 Controllers with a Long-Term Virological Remission after the Interruption of Early Initiated Antiretroviral Therapy ANRS VISCONTI Study. PLoS Pathog 9(3): e doi: /journal.ppat

45. New experimental gene
therapy/transplantation
cure approaches

46. Marsden & Zack, Bioorg Med Chem Lett. 2013

47. Treated with optimal antiretroviral therapy
Non-infected cell
Short-lived infected cell
Long-lived infected cell
(latently infected)
Virus particle
HIV-resistant cells
Conditioning therapy (destroys most immune cells)
Followed by transplant with HIV-resistant cells
Might prevent disease progression or create “functional cure”
(some virus still present but contained without drugs)

48. Experimental activation-elimination approaches to deplete latent HIV
“Kick and Kill”

49. Marsden MD, Zack JA. Future Virol. 2010 Jan 1;5(1):97-109.

50. Activation of latent provirus expression
A) Induce latently-infected cell to produce viral proteins
Activation of latent provirus expression

51. B) Kill resultant productively-infected cell
Marsden & Zack, Bioorg Med Chem Lett. 2013

52. Headlines often don’t tell the full story!

54. Take-home points:
HIV cure research is a major focus of the scientific community and governmental funding agencies.
It is hard to definitively prove that a person is cured of HIV because virus may emerge from rare infected cells many years after stopping therapy.
However, there is a single case in which HIV might have been cured (Berlin Patient).
The circumstances of this cure is highly unusual (ablative therapy, GVHD, and bone marrow transplant with resistant cells), and therefore cannot be directly applied to all infected people.
Important as proof of concept for HIV cure.
More studies are being performed to develop new cure approaches that can be more widely used.

55. Thank You!
Questions?