Department of Medicine University of Alberta Edmonton Alberta

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1 Department of Medicine University of Alberta Edmonton Alberta

2 Overview of Topics Impact of HAART on HIV neuroinvasion, neurotropism, neurovirulence. Emerging concepts derived from animal models, new technologies and recent studies in proteolytic activity Future perspectives

3 NEUROTROPIC RETROVIRUSES MuLV lentiviruses spumaviruses (HSRV) D-type (HERV-W-, SMRV) FIV EIAV HIV-1 CAEV VMV SIVagm HIV-2 SIVmac primate non-primate B-type (HERV-K, MMTV) ALV-like (RSV) HTLV-I/II LTR gag pol env LTR Power, Trends Neurosci (2001)

4 HIV-1 systemic disease course Infection Seroconversion Death Disease Progression Primary infection Asymptomatic AIDS Coreceptor use CCR5 CXCR4/CCR5 Molecular Distance from Founder Virus Viral/Host Variables CD4 + Lymphocytes Viremia 4-8 weeks 10 years 1-4 years

5 Primary HIV-induced neurological syndromes Seropositive Asymptomatic AIDS Acute meningitis Chronic meningitis GBS/CIDP Mononeuritis Neurocognitive impairment MCMD HAD Myelopathy Polyneuropathy DSP and ATN Myopathy

6 HIV neuropathology in the HAART era MGN HIV gp41 MNGC PVC

7 Depletion of HIV-1 p24-postive macrophages in brains of SCID mice by HAART Cook et al, Ann Neurol, 2005

8 AIDS-nondemented HIV Dementia MAP-2 p53 p53

9 HIV neuropathogenesis Astrocyte (activation/death) lymphocyte CD4 CCR5 Antibody response macrophage NO, QA Glutamate CXCR4 Neuroinvasion MMPs gp120, Tat Neurotropism neuron (injury/death) Neurovirulence macrophage CTL response Blood PVM Brain microglia Triggered Mechanisms: Inflammatory response Release of neurotoxic molecules Cell death/injury

10 Early brain injury in SIV-infected macaques Gonzalez et al, AIDS, 2000

11 HIV cell tropism in the CNS Gonzalez-Scarano and Martin-Garcia, Nat Rev Immunol, 2005

12 HIV-1 organ compartmentalization A subtype D subtype (B) (B) (M) (B) (B) (B) (B) (B) (M) (T) (T) (T) (T) (T) (T) B subtype Zhang et al, Virology 2001

13 Neurovirulence Mechanisms of neurodegeneration: Direct cytotoxic effects of viral proteins (gp120, gp41, Tat, Vpr) Indirect (bystander) effects of immune activation of brain monocytoid cells and/or astrocytes

14 Determinants of Neurovirulence Viral transcription Viral replication Neurotropism proviral DNA Apoptosis Apoptosis Neuroinflammation Neurotoxin induction LTR gag pol Vif Rev1 Vpu Vpr Tat1 env Rev2 Tat2 Nef LTR Tat Viral replication Neurotropism Viral variability Host transcription Neuroinflammation Apoptosis Apoptosis Neuroinflammation Neurotoxin induction

15 Direct effects of HIV proteins on neural cell viability and function Perruzi et al, BRRR, 2005

16 Indirect neurotoxicity mediated by supernatants from FIV-infected/activated macrophages % increase in neuronal death Health Disease Bragg et al, NBD, 2002

Activated microglia and macrophages: key players in brain innate immunity Normal immune sensors Activated phagocytosis chemotaxis antigen presentation cytotoxicity morphological changes proliferation

17 Activated microglia and macrophages: key players in brain innate immunity Normal immune sensors Activated phagocytosis chemotaxis antigen presentation cytotoxicity morphological changes proliferation respiratory burst MMPs, HSP proteases T CELL IFN- IL-1 ROS (NO) MMPs EAAs TNF Neuronal injury/death IL-1, IL-6, TNF MICROGLIA IL-1 IL-6 TNF ASTROCYTE microglia/ macrophage Complement components MHC II, adhesion molecules.

18 Astrocyte: the most abundant cell in the brain

19 Cell cycle genes perturbed by HIV infection of astrocytes Kim et al, JNI, 2004

20 CNS proteolytic activity: determinants of neuronal survival and death

21 Proteolytic cleavage of amyloid precursor protein (APP) I. APP 1 NH 2 II. Amyloidogenic cleavages BACE1 BACE1 671 A 770 COOH cytoplasmic -secretase EVKMDAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIATVIVITLVMLKKKQ 671 BACE1 -CTF -CTF C99 C89 -secretase A 1-40, 1-42 A 11-40, Neurotoxicity

22 Detection of intracellular -amyloid in brains of AIDS patients Green et al, AIDS 2005

23 upar is upregulated in HAD Cinque et al, Ann Neurol, 2004

24 Proteinase-activated receptors (PARs) Hollenberg et al. Pharmacol Rev. 2002

0 2.0 1.0 0.0 HIV-ND HAD * TNF- TNF-a IL-1 IL-1b * mrna RFC 7.

25 Proteinase activated receptor-2 is up-regulated on neurons in HIV-induced neuroinflammation mrna RFC HIV-ND HAD * TNF- TNF-a IL-1 IL-1b * mrna RFC HIV-ND * HAD PAR-2 Trypsinogen HIV-ND HAD

26 PAR-2 deficiency exacerbates HIV Tat-induced neuropathology and neurobehavioral deficits A KO NeuN GFAP Merged image NeuN GFAP Merged image WT B Reactivity/ Hpf WT KO * NeuN * GFAP Percent of ipsiversive rotations WT KO * Day 3 Day 7 Day 3 Day 7 Noorbakhsh et al, J. Immunol, 2005

27 Cleaved SDF-1 is highly neurotoxic and present in cortex of HAD patients SDF-1 SDF-1 SDF-1(5-67) Neuronal Death SDF-1(5-67) Control TUNEL Control SDF-1 ND HAD 40 Actin SDF (1-67) 50 SDF (5-67) * ** ** Chemokine (nm)

28 Neuropathological consequences of SDF-1 implantation PBS SDF 1-67 SDF 5-67 Microglia A B C Astrocytes D E F Neurons G H I Zhang et al, Nat Neurosci (2003)

29 Proteolysis of SDF-1 results in neuronal death HIV-infected or activated macrophage/microglia pro MMP-2 MMPI activated MMP-2 C-SDF SDF-1 Cytokines, RR, gp120 and Tat p53 G-PCR Apoptotic neuron Activated astrocyte

30 Minocycline is neuroprotective and reduces viral replication in SIV infection Zink et al, JAMA, 2005

31 Growth hormone is neuroprotective Neuronal death RFI (±SD) ** * *** *** NG108 LAN-2 *** *** % Ipsiversive rotations (±SD) Day 7 * 0 Control Tat +GH 0.1 +GH 1.0 +GH 10 +GH 100 Control Tat Tat-GH 0.5 mg/kg Tat-GH 0.05 mg/kg In vitro In vivo Silva et al, Ann Neurol, 2003

32 Growth hormone protects neural stem cells in vivo in FIV infection Fold increase * IDO Fold increase Nestin * Fold increase IGF-1 ** 0 FIV- FIV+ FIV+ &GH 0 FIV- FIV+ FIV+ &GH 0 FIV- FIV+ FIV+ &GH * P< 0.05

33 Growth hormone prevents FIV-induced immunosuppression and neurological deficits CD4 + cells 40 FIV+&GH % Cells ± SD *** FIV+ FIV Neurobehavioral score (week 12) 0 Week 8 Week 12 MDS 1 ** CD8 + cells *** 0 % Cells ± SD FIV+&GH FIV+ FIV- FIV(-) FIV(+) FIV(+) &GH *** P< ** P< Week 8 Week 12 van Marle et al, submitted

34 Future Perspectives Drug-resistant virus and neurological disease Effects of dual/suprainfections (HIV, HCV, HERVs) on neuropathogenesis Mechanisms of neurological disease in HIV-1 non-b clade infections New non-arv therapies for HIV-related neurological disorders

35 Acknowledgements NEUROVIROLOGY LAB: Guido van Marle, Farshid Noorbakhsh, Kunyan Zhang, David Vergote, Neda Sharief, Claudia Silva, Yu Zhu, Shuhong Liu COLLABORATORS: John Gill/John Wallace/Morley Hollenberg (UCal), Justin McArthur/Carlos Pardo (JHU), Chris Overall (UBC) Funds: Alberta Heritage Foundation for Medical Research (AHFMR) Canadian Institutes for Health Research (CIHR) Canadian Foundation for AIDS Research (CANFAR) National Institutes of Health (NIH)

Fayth K. Yoshimura, Ph.D. September 7, of 7 HIV - BASIC PROPERTIES

Fayth K. Yoshimura, Ph.D. September 7, of 7 HIV - BASIC PROPERTIES 1 of 7 I. Viral Origin. A. Retrovirus - animal lentiviruses. HIV - BASIC PROPERTIES 1. HIV is a member of the Retrovirus family and more specifically it is a member of the Lentivirus genus of this family.