AIDS-Acquired ImmunoDeficiency Syndrome

Lecturer: Adelheid Cerwenka, PhD, D080, Innate Immunity

Sources: Janeway: Immunobiology, 5th edition

AIDS

Definition:

AIDS is the end-stage disease caused by infection with the Human Immunodeficiency Virus (HIV)

First recognized in 1981

• General mechanisms for recognition of viruses by the immune system

• Groupwork• History of AIDS, Epidemiology• Structure of HIV • The Immune system and HIV• AIDS and other diseases (Karposi Sarcoma)• Treatment of AIDS• Perspectives

AIDS-Acquired ImmunoDeficiency Syndrome

The course of a typical acute infection

The time-course of infection of normal and immuno-deficient mice and humans

Innate immune response

Natural Killers

Macrophages

Dendritic Cells

T cells

A.) Direct recognition and elimination of

virus infected cells

Virus infected cell

Cytokines

Cell-cell contact

B.) Cross-talk with adaptive immunity

Immune response to invading viruses

• Since 1981 the syndrome known

• Los Angeles: 5 people in hospital with Pneumocystis Pneumonia.

• 1983 Virus identified HIV-1 (NIH: Robert Gallo, Luc Montagnier, Pasteur), HIV-2

History

1.) How many people in the world are infected with HIV?

2.) In which part of the world is the highest incidence?

3.) How does transmission of HIV take place?

4.) What goes wrong with the immune system?

5.) Ideas for prevention and cure?

Group work

HIV Infection is spreading over all continents

16 mio died

3.4 mio people alive with AIDS

Sahara Africa: 7% infBotswana: 30% inf

6 mio newly infected16 000 newly each day

Course of inf:10% 2-3 years AIDS80% progress in 10 years

Routes of transmission/risk groups

Hemophiliac

Intravenous drug abusers

Homosexuals

Heterosexuals

Babies of infected mothers

Routes of transmission/risk groups

Most HIV Infected people progress over a period of time

Typical course of untreated infection with HIV

The virion of HIV

2 strains of HIV-1

• CCR5: (ligands RANTES, MIP1a, MIP1b): DC, Macrophages

• CXCR4 (SDF-1): activ. T cells

• DC-Sign (possibly traps virus before encounter of susceptible cells)

Coreceptors for HIV

The infection of CD4 T cells with AIDS

Genes and proteins of HIV

Only activated cells become infected

The immuneresponse to HIV

• Problems: virus mutates, virus is hiding in storage sited (in mucosa, brain).

• CD4 T cells: help is missing

• CD8 T cells: Good in the beginning, later they can’t see the mutated virus,

• B cells: good, but Ab is directed against the initial virus

Immune response against HIV

• Lymphoid tissue

• Nervous system

• Gastrointestinal tract

• Cancer: Karposi Sarcoma

Organs affected with AIDS-lymphoid tissue