Download presentation
Presentation is loading. Please wait.
Published byClemence McBride Modified over 9 years ago
1
THE IMMUNOPATHOGENESIS OF HIV INFECTION
5
THE HUMAN IMMUNODEFICIENCY VIRUS (HIV) 10359bp DNA gp120 gp41 CD4 binding Membrane fusion
6
Forrás: www.hopkins-aids.edu
21
RECEPTORS AND CO-RECEPTORS I. CD4 is a high affinity receptor for HIV gp120 CD4 CCR5 CCR5 co-receptor on monocytes, macrophages and T cells R5 strain of the virus in initial infection CD4 CXCR4 CXCR4 co-receptor on T cells X4 strain of the virus in initial infection Conformational change of gp120 Conformational change of gp41 MEMBRANE FUSION
22
MistakesEnzyme 1 Mutation in 10 5 bp Reverse Transcriptase DNA-Polymerase 1 Mutation in 10 8 bp THE CAUSE OF HIV VARIABILITY THE VIRAL REVERSE TRANSCRIPTASE LACKS PROOF READING MECHANISMS OF TYPE POSSESSED BY CELLULAR DNA NEW VIRAL VARIANTS (quasi species) CO-EXIST IN AN INDIVIDUAL NEGATIVE SELECTION OF NEUTRALIZING AND CYTOTOXIC EPITOPES
23
9% of the Caucasian population is heterozygous for a deletion mutant of the CCR5 gene, which results in an unfunctional protein People homozygous for an inherited defect of the CCR5 gene are resistant to HIV infection – 1% of the Caucasian population
24
DEPLETION OF CD4+ CELLS IN HIV INFECTION
25
CD4+ T CELL DEPLETION IN HIV INFECTION Loss of CD4+ T cells in lymphoid organs 1.Direct cytopathic effect of HIV – lytic cycle in activated CD4+ T cells 2.Killing by virus-specific CD8+ T lymphocytes – CD4+HIV+ targets 3.Uninfected CD4+ T cells bind gp120 – CD4 + TCR signaling apoptosis 4.Syncytia formation – gp120 of infected T binds to uninfected T fusion 5.Inhibited T cell development
26
THE COURSE OF HIV INFECTION
28
OPPORTUNISTIC INFECTIONS AND TUMORS IN HIV INFECTION
29
KAPOSI SARCOMA AND HERPES SIMPLEX VIRUS INFECTION IN HIV-INFECTED PATIENTS
30
Candia albicans infection
31
Three main transmission routes for HIV have been identified Sexual The risk of female-to-male transmission is 0.04% per act and male-to-female transmission is 0.08% per act.
32
Blood products Blood transfusion, intravenous drug users, piercings, tattoos
33
Mother-to-child The risk of transmission is 20-33 %. Perinatal > intrauterin > breast feeding
34
HIV-1-SPECIFIC CD4+ HELPER, CD8+ CYTOTOXIC T CELLS AND VIRAL LOAD PROGRESSIVENON-PROGRESSIVE HAART THERAPY PRIOR OR AT THE TIME OF SEROCONVERSION? Zidovudin can protect against transmission to the infant Goulder 1999, Altfeld &Rosenberg 2000
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.