HIV Infection Chapter 30 Lesson One pg. 658

Global burden of HIV Over 25 million have died from AIDS leading cause of death in developing countries (WHO 2002) 4 th leading cause of death worldwide (WHO 2002) The infection is a co-factor for other diseases 42 million currently living with HIV (UNAIDS end 2002) 5 million people were newly infected with HIV in 2002, 800,000 of those under 15 years (UNAIDS end 2002)

Definitions HIV (Human Immunodeficiency Virus) Attacks the body’s immune system It replicates and kills the helper T cells AIDS (Acquired Immune Deficiency) HIV combined with severe immune deficiency final stage of infection with HIV

Definitions cont’d Lymphocytes- help your body fight disease causing organisms or pathogens B cells- mature in bone marrow T cells- mature in thymus gland T helper cells- stimulate B cells to produce antibodies  Antibodies- proteins that help destroy pathogens that enter the body

MissionSBRIGlobal Infectious DiseasesSBRIGlobal Infectious Diseases Envelope or “Env” Envelope protein is compact and “closed” HIV approaches a cell… Cell interior

MissionSBRIGlobal Infectious DiseasesSBRIGlobal Infectious Diseases Cell interior Binding Changes the Shape of Env …and exposes common regions shared by all Envelope proteins worldwide …and if not blocked, will enter the cell and become a permanent part of the DNA

MissionSBRIGlobal Infectious DiseasesSBRIGlobal Infectious Diseases Killer T cells kill HIV-infected cells …by recognizing HIV proteins expressed on cells making virus and delivering a death signal T-cell

MissionSBRIGlobal Infectious DiseasesSBRIGlobal Infectious Diseases Non-neutralizing Neutralizing Neutralizing antibodies block HIV …neutralizing antibodies that block infection are a major “missing component” in vaccines, despite 20 years of effort

Myths  You can get HIV from swimming in a pool with someone who is infected  You can get HIV from a mosquitoes bite if a mosquito has bitten an infected person  You can get HIV from being sneezed on

Facts  Even if an HIV-infected person bled into a swimming pool, the blood would be so diluted it would be harmless

Risky Behaviors  Sexual Intercourse  Sharing Needles  Blood transfusions  Mother-to–child birth

AIDS vaccines: good news  Vaccines block infection in some animal models for AIDS  Vaccines that do not block infection can slow disease & death in animal models  We have more tools to control HIV, buying us time for vaccine development  The world research community is beginning to work more effectively to bring vaccines to testing worldwide