1. Microbiology B.E Pruitt & Jane J. Stein AN INTRODUCTION EIGHTH EDITION TORTORA FUNKE CASE Chapter 19, part B Disorders Associated with the Immune System

2. Acquired Immunodeficiency Syndrome (AIDS) 1981In U.S., cluster of Pneumocystis and Kaposi's sarcoma in young homosexual men discovered. The men showed loss of immune function. 1983Discovery of virus causing loss of immune function.

3. Acquired Immunodeficiency Syndrome (AIDS) Figure 19.12a

4. Crossed the species barrier into humans in Africa in the 1930s Patient who died in 1959 in Congo is the oldest known case Spread in Africa as a result of urbanization Spread in world through modern transportation and unsafe sexual practices Norwegian sailor who died in 1976 is the first known case in Western world The Origin of AIDS

5. HIV Infection Figure 19.12b

6. HIV Infection Figure 13.19 Retrovirus penetrates host cell. Virion penetrates cell and its DNA is uncoated The new viral DNA is tranported into the host cell’s nucleus and integrated as a provirus. The provirus may divide indefinitely with the host cell DNA. 1 2 3 DNA Transcription of the provirus may also occur, producing RNA for new retrovirus genomes and RNA that codes for the retrovirus capsid and envelope proteins. 4 Mature retrovirus leaves host cell, acquiring an envelope as it buds out. 5 Capsid Reverse transcriptase Virus Two identical + stands of RNA DNA of one of the host cell’s chromosomes Provirus Host cell Reverse transcriptase Viral RNA RNA Viral proteins Identical strands of RNA

7. HIV Infection Figure 19.13

8. HIV Infection Figure 19.14

9. Category AAsymptomatic or persistent lymphadenopathy Category BPersistent Candida albicans infections Category CClinical AIDS. CMV, TB, Pneumocystis, toxoplasmosis, Kaposi's sarcoma The Stages of HIV Infection

10. Figure 19.15

11. Some Common Diseases Associated with AIDS Table 19.5

12. Seroconversion takes up to 3 months HIV antibodies detected by ELISA HIV antigens detected by Western blotting Plasma viral load is determined by PCR or nucleic acid hybridization Diagnostic Methods

13. HIV survives 6 hours outside a cell HIV survives >1.5 days inside a cell Infected body fluids transmit HIV via: –Sexual contact –Breast milk –Transplacental infection of fetus –Blood-contaminated needles –Organ transplants –Artificial insemination –Blood transfusion HIV Transmission

14. Modes of HIV Transmission Figure 19.17

15. U.S., Canada, western Europe, Australia, northern Africa, South America –Injecting drug use, male-to-male sexual contact Sub-Saharan Africa –Heterosexual contact Eastern Europe, Middles East, Asia –Injecting drug use, heterosexual contact AIDS Worldwide

16. Figure 19.16

17. HIV-1 is the most common. It has 11 clades: –90% of U.S. infections caused by clade B –Clade C predominates in sub-Saharan African –Clades B, C, & E are in south and southeast Asia HIV-2 is seen in western Africa Clades

18. Use of condoms and sterile needles Health-case workers use universal precautions –Wear gloves, gowns, masks, goggles –Do not recap needles –Risk of infection from infected needlestick injury is 0.3% Prevention of AIDS

19. Whole-cell Salmonella with gp120 gene Subunit vaccine using gp120 expressed in Saccharomyces Canarypox virus with HIV capsid protein genes Naked DNA consisting of tat (transcription factor) or gag (capsid protein) genes Vaccines in Clinical

20. Nucleotide Reverse Transcriptase Inhibitors Non- Nucleoside Reverse Transcriptase Inhibitors Protease Inhibitors Virus decoys Chemotherapy

21. Combinations of nucleoside reverse transcriptase inhibitors + –Non-nucleoside reverse transcriptase inhibitor or –Protease inhibitor Highly Active Antiretroviral Therapy (HAART):