Immunology Exam 6 Chapters 11 And 12 Study Guide
PCB Fall 14 Study guide
Chapter 11
1) Which T-cells decline in an HIV patient? What is the significant # of those cells for a transition to AIDs?
a. Massive reduction in CD4 T cells
b. Less than 200 CD4 T cells per ul.
c. HIV doesn't kill patient but cell mediated immunity is compromised and patient can die from infection
2) Know gp 120 and 41 and what they do? What is the precursor polypeptide these are created from?
a. One nucleocapsid protein is a protease used to cleave gp41 and gp120 envelope glycoproteins from a larger precursosr protein.
b. cleave a large precursor polyprotein (protein gp160)
c. binding and fusion of HIV into target cell takes place by interaction with 2 membrane glycoproteins (GP)
i. gp120- binding ii. gp41- fusion iii. major cellular receptor is CD4- TH cells are the prime targets.
3) What are tat, rev, protease, integrase and reverse transcriptase and what is the function of each? Are all of these brought (premade) by the virus when it infects the cell or are some made after the cell is infected? Which have to be made after infection?
a. Protease’s job is to cleave a large precursor polyprotein (protein gp160)
i. Gp41 and gp120 envelope glycoproteins.
b. RNA genome is copied using reverse transcriptase (cDNA)
c. Viral integrase then integrates the cDNA into the host’s genome (provirus now formed)
d. Provirus uses the hosts transcriptional and translational machinery to make viral proteins and RNA genomes. (Integrase, protease, reverse transcriptase come prepackaged with virus).
e. Tat amplifies transcription of viral RNA
i. T cell activation induces transcript ion of RNA transcripts, which are spliced to allow synthesis of Tat and Rev. ii. Binds to transcription activation region of viral mRNA and prevents transcription form shutting off.
f. Rev increases transport of singly spliced or unspliced viral RNA to cytoplasm. Delivers RNA that encodes proteins necessary to make virons.
4) How many RNA molecules make up HIV genome? How
Chapter 11
1) Which T-cells decline in an HIV patient? What is the significant # of those cells for a transition to AIDs?
a. Massive reduction in CD4 T cells
b. Less than 200 CD4 T cells per ul.
c. HIV doesn't kill patient but cell mediated immunity is compromised and patient can die from infection
2) Know gp 120 and 41 and what they do? What is the precursor polypeptide these are created from?
a. One nucleocapsid protein is a protease used to cleave gp41 and gp120 envelope glycoproteins from a larger precursosr protein.
b. cleave a large precursor polyprotein (protein gp160)
c. binding and fusion of HIV into target cell takes place by interaction with 2 membrane glycoproteins (GP)
i. gp120- binding ii. gp41- fusion iii. major cellular receptor is CD4- TH cells are the prime targets.
3) What are tat, rev, protease, integrase and reverse transcriptase and what is the function of each? Are all of these brought (premade) by the virus when it infects the cell or are some made after the cell is infected? Which have to be made after infection?
a. Protease’s job is to cleave a large precursor polyprotein (protein gp160)
i. Gp41 and gp120 envelope glycoproteins.
b. RNA genome is copied using reverse transcriptase (cDNA)
c. Viral integrase then integrates the cDNA into the host’s genome (provirus now formed)
d. Provirus uses the hosts transcriptional and translational machinery to make viral proteins and RNA genomes. (Integrase, protease, reverse transcriptase come prepackaged with virus).
e. Tat amplifies transcription of viral RNA
i. T cell activation induces transcript ion of RNA transcripts, which are spliced to allow synthesis of Tat and Rev. ii. Binds to transcription activation region of viral mRNA and prevents transcription form shutting off.
f. Rev increases transport of singly spliced or unspliced viral RNA to cytoplasm. Delivers RNA that encodes proteins necessary to make virons.
4) How many RNA molecules make up HIV genome? How