Transcript Immune Response to HIV Infection

Immune Response to HIV
Infection
June 28, 2001
Ms. Jane Coyle-Morris
Wyeth-Ayerst Research
Immune Response to HIV
Infection
 Immunology
 HIV Biology
 Immune Response to HIV Infection
Role of Antibodies
Antibody interaction with Complement Proteins
Cytotoxic T-Cells
Central Role of Helper T-Cells
Macrophage
Large, irregularly-shaped
phagocytic cells that act as
the body’s scavengers.
Macrophages engulf and
consume foreign material
such as bacteria and
viruses.
T Cells
Arise from stem cells
in the bone marrow
then migrate to the
thymus gland where
they develop the
ability to recognize
foreign antigens in a
specific manner.
Helper T Cells (TH)
Detect infection and initiate both humoral
and cell-mediated responses (CD4 cells)
Cytotoxic T Cells (TC)
Recruited by TH to lyse infected body cells
(CD8 cells)
Cell Marker Proteins
 CD4:
cell marker found on the surface of TH
and macrophages; acts as a receptor for
HIV
 CD8: cell marker found on the surface of TC
B Cells and Plasma Cells
 B Cells:
precursors of plasma
cells, specialized to
recognize particular foreign
antigens
 Plasma Cells: derived from B
cells, they produce
antibodies to specific
antigens marking them for
destruction
Major Histocompatibility
Complex (MHC)
 Proteins markers found on the surface of
the body’s cells to signal “self” from “nonself”. MHC-I can be found on every cell in
the body while MHC-II is found only on B
cells, T cells and macrophages.
Cytokines
 Soluble proteins secreted by the cells of
the immune system to signal activation and
proliferation of the appropriate
components of the immune response. IL-1
is released from macrophages and signals
activation of T cells. Activated T cells
produce IL-2 which signals proliferation of
T cell clones and also helps B cells to start
secreting antibodies.
Cytokines
The Immune Response
Central Role of CD4 T Cell
HIV Biology
HIV in Action
Natural Course of HIV Infection
Overview
Immune Response to HIV
Infection
 Immunology:
humoral vs. cell-mediated
 HIV biology: complex series of events
leading to viral entry and course of
infection; evasion of immune system
 Immune response to HIV: weak humoral
response, strong cell-mediated response
diminished over time by depletion of helper
T-cells
AIDS/HIV Internet Sites
Www.ama-assn.org/special/hiv/hivhome.htm
 www.planetq.com/aidsvl/index.html
 www.thebody.com/cgi-bin/body.cgi
 www.cdc.gov/
 www.pbs.org/wgbh/nova/aids/
 www.roche-hiv.com/default.htm
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