1. Understanding The Role Of SAMHD1 in HIV1/2 Pathogenesis
Maha Al-Mozaini, Ph.D.
Immunocompromised Host Research
King Faisal Specialist Hospital and Research Centre
Riyadh Saudi Arabia

2. Riyadh Saudi Arabia

4. King Faisal Specialist Hospital and Research Centre

5. Acquired Immune Deficiency Syndrome (AIDS)
Human Immunodeficiency Virus (HIV)

6. HIV vaccine development
Two major challenges
HIV vaccine development
Cure of HIV-1 infection

7. HIV in Saudi Arabia
Antiretroviral resistance in HIV-infected Saudi children failing first-line highly active antiretroviral therapy.
Al Hajjar SH1, Frayha H, Althawadi S.
Human immunodeficiency virus type 2 in two Saudi families
Reem S. Almaghrabi, Batool Ali, Sahar Al-Thawadi, Magid Abdel Halim, Abdulrahman A. Alrajhi .
HIV-associated nephropathy in Saudi Arabia.
Al-Sheikh H1, Al-Sunaid M, Alrajhi AA.
Isolation of a rare Nocardia wallacei from an HIV-positive patient with pulmonary infection in Southern Saudi Arabia.
Hamid ME1, Al Azraqi TA, Joseph MR, Al-Hakami AM.

8. HIV Research
One of the major barriers to HIV-1 vaccine development is a lack of understanding of the correlates of protective immunity against the virus.
A growing interest of the HIV scientific community is in studying a minority of HIV-1-infected patients who control virus replication and remain asymptomatic without any therapeutic intervention;
HIV-1 Long-term nonprogressors (LTNPs) or Elite Controllers (EC)
HIV-2
Simian Immunodeficiency Virus (SIV)

9. HIV
HIV-1
HIV-2

10. HIV-2/SIV Gene Sequence
HIV Genome
LTR
Pol
Gag
Vif
Vpr
Vpu
Env
Nef
HIV-1 Gene Sequence
Vpx
LTR
Pol
Gag
Vif
Vpr
Vpu
Env
Nef
HIV-2/SIV Gene Sequence
Ayinde et al. Retrovirology 2010.

11. Intracellular Transcription Factors
APOBEC3
Tetherin
TRIM
SAMHD1
Sheehy et al., 2002, Neil et al., 2008, Sebastian & Luban, 2005 & Laguette et al, 2011

12. SAMHD1 Cellular Protein encoded by SAMHD1 gene
Sterile Alpha Motif Domain And Histidine Aspartic Domain Containing Protein 1
Cellular Protein encoded by SAMHD1 gene
Found in myeloid cells and resting CD4 T cells
Phosphohydrolase Activity
Convert nucleotide triphosphate (NTP) to nucleoside & triphosphate
Deplete the pool of nucleotides available to
a reverse transcriptase for viral cDNA synthesis
Prevent viral replication
RNase Activity
Restrict the HIV-1 infection in Phosphorylation SAMHD1
Without decreasing cellular dNTP levels
Lahouassa et al, 2012 & Ryoo et al, 2014

13. SAMHD1
Vpx Blocks SAMHD1 .
St Gelais C & L Wu, 2011.

14. Aims
Evaluate the protein interaction of Vpx with SAMHD1 in transfected cell lines.
Analyze the protein expression of SAMHD1 in different HIV infected cells.
Profile the immune response in different HIV infected Patients and it relation to Vpx.
So we wanted to investigate the following ‘mention what's above’

15. HIV Patients HIV Patients Viral Load CD4 (copies/ml) (cells/mm3) HIV-1
214
200
HIV-2
<50
400

16. SAMHD1 and Vpx in Transfected Cells
pcDNA 3.1
72KD
36KD
14KD
Anti-SAMHD-1
Anti-GAPDH
Anti-Vpx
pcDNA 3.1 +VPX
THP-1 cells
THP-1 cells
DAPI
Anti-Vpx
Anti-SAMHD-1
pcDNA 3.1
Mock
VPX

17. SAMHD1 and Vpx in PBMCs Cells
HIV-2 PBMCs
(On Treatment)
72KD
36KD
14KD
Anti-SAMHD-1
Anti-GAPDH
Anti-Vpx
180KD
HIV-2
(A)
(B)
HIV-1
Neg
HIV-2 PBMCs
(Before Treatment)
72KD
36KD
14KD
Anti-SAMHD-1
Anti-GAPDH
Anti-Vpx
180KD
HIV-2
(A)
(B)
HIV-1
Neg

18. Monocyte Derived Dendritic Cell (MDDC)
SAMHD1 and Vpx in MDDC Cells
PBMCs
Monocyte
Monocyte Derived Dendritic Cell (MDDC)
MDDC Cells
72KD
36KD
14KD
Anti-SAMHD-1
Anti-GAPDH
Anti-Vpx
HIV-2
(A)
(B)
HIV-1
Neg

19. Transcription level of SAMHD1

20. Cytokine Analysis

21. Conclusion
Establish a transfected cell line to confirm SAMHD1 and Vpx interaction.
Our results confirmed the true interaction of Vpx and SAMHD1 using cells from HIV-2 infected patient.
The finding of immune modulator SAMHD1 as a restriction factor in DC opens a new area of investigation in DC-target vaccination strategies.
Preliminary data of cytokines expression in Vpx cell lines was established.
Established a transcription assay for Vpx gene.

22. HIV-2 serves an important model of natural attenuated lentivirus infection

23. Future prospective
Investigating the possible role of the mutated gene(s) in Aicardi–Goutieres syndrome in HIV infection.
Recent studies suggest that elite controllers maintain a steady level of HIV-1 replication without treatment because of overexpression of p21 & reduced CDK9.

24. Finding a cure for HIV will require innovation, collaboration and significant funding

25. COLLABORTERS Abdurahman Al-Rajhi Abdullah Al-Hokail Magid A Mohmed
Hail M Al-Abdely
Fahad A Al-Rabiah
Ali Omrani
Eric Rosenberg
Mathias Lichterfeld
Michael Mansour
Xu Yu
Bruce Walker
Nathaniel Landau
Uday Kishore

26. Acknowledgment RC Administration Dr. Sultan Al-Sedari
Immunocompromised Host
Research Department Of Infection
& Immunity
Mohammed Al-Ahdal
Walaa Al-Arnous
Ibtehaj Al –sharif
Ahlam Bokh
Jorge Bautista
Qais Dirar
Hanan Sharawi
Mureen Del Cruz