Summary:Microbe Interactions

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SummaryMicrobe Interactions
In vivo, co-infection is the norm

• Does interaction primarily affect HIV, the
  coinfecting organism or both?
• Is the effect direct or indirect?
• Opportunity to interact?
• Is coinfection transient or persistent?
• What is geographic distribution?

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Meta-analysis GBV-C viremia measured later in
HIV Infection and survival in 1,294 individuals
HR (95 CI) 0.52 (0.32, 0.85) model 1 0.69 (0.40,
1.18) 0.36 (0.17, 0.75) 0.29 (0.20, 0.41) 0.15
(0.05, 0.40) 0.58 (0.15, 2.21) 0.37 (0.21, 0.64)
n 1294
Modified from Zhang et al.,. HIV Med, 2006
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Types of interactions

• Direct effects and transmission
• Indirect effect on cells
• A. Immunological recognition
• B. Activation
• C. Alter chemokines and cytokines
• D. Modulate HIV receptor density
• E. Alter HIV transcription
• F. MDM endosomal maturation
• G. Other unknown mechanisms?

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Examples from IAS Sydney

• Bacteria Gut bacteria, mycobacteria, syphilis,
  other STIs,
• Protozoa T cruzi, malaria
• Viruses HHV-6, HHV-7, HHV-8, vaccinia, HCV,
  HPV, HSV, GBV-C, Dengue HIV-2, BK/JC,
  HBV

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IAS 2007 HIV pathogenesis, treatment and
prevention

• 1. Better understand mechanisms
• A. Reproduce-stimulate known mechanisms e.g.
  receptors, chemokines, cytokines
• B. Identify new restriction factors
• C. OI prevention strategies
• 2. Evaluation of co-pathogens important in
  vaccine, Rx, and epidemiological studies
• 3. Directly test co-infection?

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Conclusions

• 1. Co-infection is the norm
• 2. Interactions negative or beneficial
• 3. May effect either microbe
• 4. Need to better understand the
  mechanisms of these interactions