TIBETAN PERSONALITY TEST

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HIV BIOLOGY
Pr. Justin Wane Project Officer
HIV/AIDS Association of African
Universities jwane_at_aau.org
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BASIC VIROLOGY

• VIRUSES
• Smallest known infective organisms
• Reproduce by using mechanisms of host cells
• Genetic material either DNA or RNA
• Several families of Viruses
• Have affinity for specific host cell
• HIV
• Human Immunodeficiency Virus

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HUMAN IMMUNODEFICIENCY VIRUS

• Belongs to the Family Retroviruses
• Retro ? backward
• RNA ? DNA (usual flow is DNA-RNA)
• Genus Lentivirus
• Involvement of nervous system
• Clinical latency
• Weak humoral immune response

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HIV-1 Structure
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HIV TYPES
HIV 2
HIV 1
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SIMILARITIES
HIV TYPES

• Both associated with AIDS,
• Tendency to cause slowly progressive but lethal
  disease,
• Ability to persist within cells

DIFFERENCES

• Differ by 60 in genetic make-up
• Major difference in envelop glycoproteins
• HIV1 (gp120 gp41) HIV2 (gp105 gp36)

? Co-infection by both viruses is possible
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DIFFERENCES (contd)
HIV TYPES
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HIV-1 GENOME

• Consist of 3 major genes
• gag ? P24, P18, P15
• env ? gp120, gp41 (gp160)
• pol ? enzymes (RT, PRT, INT)
• Other 6 minor genes
• vif, vpu, vpr,tat, rev, nef

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STRUCTURE OF THE HIV GENOME
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HIV SUBTYPES

• HIV-1
• Three groups
• Group M (Major) 9 subtypes (A-D, F-H, J, K)
• Group N (Non-M, Non-O or New)
• Group O (Outlier)

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Geographic distribution of HIV 1
A
B
C
CRF1_AE
CRF2_AG
CRF3 AB
CRF4_CP
D
F
G
H
J
O
Complex
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LIFE CYCLE OF HIV
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1. Attachment
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2. Reverse Transcription
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 3. Integration
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4. Transcription
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5. Translation
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6. Viral Assembly
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Natural History of HIV Infection
Two different parameters

• Viral load evolution speed
• CD4 count Distance to the Term

Viral load
CD4 COUNT
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THANK YOU !