HIV - PowerPoint PPT Presentation

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HIV

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Title: PowerPoint-Pr sentation Author: Dept.Pathologie Last modified by: sham Created Date: 1/8/2003 8:19:49 AM Document presentation format: Bildschirmpr sentation – PowerPoint PPT presentation

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Title: HIV


1
HIV FIV - LCMV
  • Immune system viruses
  • Tricks of pers. VT deletion / escapenAb delay
    / escape
  • Re-encountered / persistent antigen maintains nAb
    (successful vaccines) and act. T (infection
    immunity no vaccine) for protection

2
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3
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4
LCMV-viremia control or nAb escape
Ciurea, Hunziker et al.
5
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8
  • Prevent penetration IgA
  • systemic neutr.-opson.IgM/G
  • adoptive transferable IgG
  • IgM 1-2d, regulated byAg-dose and structure(no
    negative selection)

B Ab
  • Control-elim. intracell parasites also in solid
    organs
  • regulate longterm IgG
  • cause imunopathology(negative selection)

T
9
reverse genetic glycoprotein exchange between
LCMV and VSV Pinschewer, de la Torre et al.
rLCMV/INDG
rVSV/LCMV-GP
glycoprotein LCMV-GP
glycoproteinIND-G
LCMV
VSV-IND
glycoprotein LCMV-GP
glycoproteinIND-G
10
Only VSVG expressing viruses induce a
neutralizing antibody response
11
Neutralising Ab GP structure
  • early TH independent IgM, germline high
    affinity / avidity
  • late immunosuppression ? affinity maturation?

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13
Hypergammaglobulinemia vs. neutralizing antibodies
Hypergammaglobulinemia
Neutralising antibodies
Neutralising antibodies
Recher, Lang, Hunziker 2004
14
  • Conclusion
  • Many nAb "specificities" control V, if "one" too
    slow/low V-escape!
  • Hypergammaglobulinemia and polyclonal B cell
    activation compete with nAb responses and seem to
    depend upon amount of virus-specific CD4T cells.
  • Mechanisms of B cell competition? (Cytokine
    receptor competition? Anatomic competition in
    germinal centers? Competition for anti-apoptotic
    cytokines?).

15
Why autoimmune disease inhumans mostly via
antibodies?
Memory vs. Protection
First infection kills hostno memory needed Host
survives first infectionmemory not necessary
  • Why gtgt !Why all vaccines that function
    protect via neutr. antibodies?

16
No protection by Memory B cells but protection by
immune serum in IFN-aBR_/_ against VSV
VSVIND immune spleen cells TB LCMV
immune spleen cells VSVIND Ab
Anti-VSV neutr. AB lt 1 40 lt 1
40 lt 1 2500
Survivors 0 0 100
17
Maintenance of protection
  • 1. Agent persists TB, leprosy, HIV, HCV, LCMV
  • Herpes viruses
  • crippled measles?
  • 2. Repetitive inf. polio, bact. toxins
  • 3. Antibody-antigen complex depots in lymph
    nodes and spleens

18
persistent virusfrom mother
19
Poliomyelitis age distribution in Massachusetts
1912 1952
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21
Memory / Pregnant Female
  • Academic earlier higher (AG )
  • Immune against cytopathic infectionsotherwise
    abortions / malformations
  • MHC-incompatibility offspring / mother
  • Maternal antibodies attenuate acute
    infectionsphysiological vaccinations (incl.
    malaria, eggs)
  • Non-cytophatic infections transferred via
    placenta / at birth / after birth (LCMV, HCV,
    Herpes)
  • Resistance via T cells HIV, HTV, TB Lepr. slow
  • "Emerging" infections

22
Conclusions
  • Persistent infections numbers / variability
  • T cell control immunopathology "tolerance"
  • nAb essential (affinity maturation?) or escape
  • antigen maintains nAb titers and act. T cells
    (but immunopathology!)
  • All successful vaccines nAb not successful
    should (also) maintain act.T (not achieved yet)

23
H. Hengartner
  • Battegay
  • Ciurea
  • Hunziker
  • M. Recher
  • U. Steinhoff
  • Odermatt
  • Th. Leist
  • Lang
  • Pinschewer
  • J. de la Torre

24
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26
IMMUNITY
  • innate resistance gt 95
  • Ab in eggs
  • protective memory via Ab (vaccines)
  • TB no vaccine
  • autoimmunity gt 30 y, female gt male 5 1
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