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Virsuses: Human Immunodeficiency Syndrome & Acquired Immunodeficiency Syndrome. Outline. Introductory Comments Virus versus bacteria Examples of DNA and RNA containing viruses How RNA containing viruses can replicate Origins of HIV Dr. Hahn and colleagues Characteristics of HIV Particle
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Virsuses:Human Immunodeficiency Syndrome& Acquired Immunodeficiency Syndrome
Outline • Introductory Comments • Virus versus bacteria • Examples of DNA and RNA containing viruses • How RNA containing viruses can replicate • Origins of HIV • Dr. Hahn and colleagues • Characteristics of HIV Particle • Glycoproteins • Viral genes • Laboratory Diagnostic Tests • PCR • Western Blot • ELISA • -------------------------------------------------- Part 2 ------------------------- • Treatment • Transmission • Prevention
Note: These STDs are bacterial infections! • SYPHILIS • Bacterium: Treponema pallidum • GONORRHEA • Bacterium: Neisseria gonorrhoeae
Viruses • DNA containing • RNA containing
DNA containing viruses • Herpes virus • Small pox virus • Hepatitis B • adenovirus
RNA containing viruses • Hepatitis A and C • Rabies • Ebola • Measles • Mumps • Polio • HIV Rabies virus Measles on the back
Examples of how RNA viruses replicate Negative strand Positive strand Retro
HUMAN IMMUNODEFICIECY VIRUS • Family: retrovirus • Genus: lentivirus • Species: HIV 1 and HIV 2 • Groups and Subtypes: variety
Africa Americas China (southeast) Europe India Japan Thailand A;D;C B C B C B E “Predominant Subtypes of Group M”
Dr. Beatrice Hahn & colleagues: Drs. Li and Keele
Greater spot nose monkey Red Cap Mangabey monkey SIV cpz almost identical to HIV 1 Humans
Pan troglodytes troglodytes Simian Virus (SIV cpz) almost identical to HIV 1
Sooty mangabey monkey Simian Virus corresponds to HIV2
HIV: Structure and mechanism of replication
HIV Glycoproteins • Lipid Bilayer contains glycoproteins • Gp 160 • Gp 120 • Gp 41
HOST CELLS:helper T lymphocyte, macrophages HIV and helper T cells HIV-1 http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter24/animation__hiv_replication.html
Budding of HIV from T lymphocyte HIV HIV
Mechanism of Infection Infects Th cell VIRAL RNA Integrates into host DNA “activated” PROVIRAL DNA LYTIC STAGE storage LYSOGENIC STAGE
Co-Receptors Binds naturally occurring chemokines CCR5 or CXCR4 (fusin)
HIV Diagnostic Tests • Western Blot • PCR Directly measures HIV
Polymerase Chain Reaction • Measures proviral DNA within the host DNA
Western Blot Identifies HIV proteins Protein ladder
HIV Diagnostic Tests • ELISA measures Indirect evidence of HIV exposure
Enzyme Linked Immunosorbent Assay (ELISA) • A diagnostic test for Antibodies to HIV Antibodies
*Antibodies are proteins produced by our immune system that are directed against specific antigens.(Antibody interactions with antigens will also be discussed in our “immungenetics lecture”)
Antibodies Antigens Immune system Non-self
Now apply these concepts to the diagnostic test known as ELISA to detect antibodies against HIV from a biologic fluid.
ELISA MICROTITER PLATES Microtiter plate
The ELISA protocol sample Labelled 2nd Ab antigen 3 2 1 4 Color inducing substrate
Results POSITIVE ANTI-HIV COLOR CHANGE NEGATIVE ANTI-HIV NO COLOR CHANGE
FDA Approves Saliva OraQuick Rapid Test for HIV-1, HIV-2 Antibodies[March 29, 2004] (similar test is also available for blood samples, see next slides).
1 2 OraQuick Rapid Anti-HIV Blood Test 20 minute test Cost app. $15.00 3
Outline • Introductory Comments • Virus versus bacteria • Examples of DNA and RNA containing viruses • How RNA containing viruses can replicate • Origins of HIV • Dr. Hahn and colleagues • Characteristics of HIV Particle • Glycoproteins • Viral genes • Laboratory Diagnostic Tests • PCR • Western Blot • ELISA • -------------------------------------------------- Part 2 ------------------------- • Treatment • Transmission • Prevention