Experiment Table CD4+ T lymphocyte counts and viral RNA Results Tetramer Staining Results Neutralizing Antibody Assays Results Viral Sequencing Results Peptide-binding Assays Results ELISPOT assays Results Conclusion   Navigation Home Methods Results Conclusion Quiz Links   Quiz MC 2p each T/F 1p each Match 5p set 25-21 Genius Probably wrote the paper 20-16 Sharp Reads way too much 15-11 Adequate Studies enough to get by 10-6 Poor Needs to hit the books 5-0 Abysmal Beyond the help of even this module	QUIZ   Multiple Choice 1. By replication breakthrough, the researchers mean... Burst of production of immune cells Wrong Herpes Induced Variability False Sudden increase in replication of virii True   2. The virus SHIV is a hybrid of HIV and SIV True A new previously unknown virus Wrong A monkey Wrong   3. The reseachers found that all subjects except for 798 maintained stable levels of CD4 cells and undetectable levels of viral RNA. What happened to 798 that didn't happen to the other subjects by the time the paper was written. Subject 798 died of unrelated complications False Subject 798 experienced replication breakthrough True Subject 798 continued to live past expectancy while other subjects died of SHIV False   4. After week 14 a single nucleotide substitution was observed in the segment encoding the Gag p11C epitope. It was concluded that this nucleotide substitution helped lower the affinity of p11C for the Mamu A*01 MHC molecule. What is the mostly likely reason for this? Even small changes can drastically alter viral proteins and prevent recognition. True The altered protein encoded an inhibitor that would compete for MHC binding False There is not enough information to make a hypothesis. False   5. Viruses like SHIV often are described as maintaining several 'quasispecies' or subpopulations in the body. This is due to the inherent instability of the viral genome. One advantage to this strategy is that the virus keeps around a large pool of genetic variability to help replace its numbers during immune and drug pressure. One of the disadvantages is... potentially having a number of virus that are defective or of reduced fitness True Killing off host before virus can spread to others in a population. False not being able to evolve complex mechanisms Possibly true, but first choice is a better answer
	True/False 1. SHIV was used instead of HIV because it was able to infect rhesus monkey cells. Answer True   2. Immune pressure does not cause mutations to appear but merely selects those that already are present. Answer True   3. The rapid replacement of SHIV quasispecies with new populations containing beneficial mutations shows that the immune system is unable to exert significant pressure, since the virus is able to evolve unhindered Answer False   4. Subdominant CTL epitopes Gag LW9 and Env p41A have high mutation rates comparable to background mutations since they are under high immune pressure. Answer False   5. The viral replication breakthrough in subject 798 indicated that even animals with undetectable levels of plasma SHIV RNA have enough replication continuing to develop epitopes that can evade the immune system.   Answer True
	Matching 1. 1. SHIV 2. Gag p11C 3. Rhesus Monkeys 4. Mamu A*01 5. Cytotoxic T lymphocytes Hybrid of HIV and SIV SHIV Cells that destroy infected tissue Cytotoxic T lymphocytes Binds foreign epitopes Mamu A*01 Location of nucleotide substitution Gag p11C Animals used in these experiments Rhesus Monkeys
	2. 1. ELISPOT 2. quasispecies 3. subdominant CTL epitopes 4. IL-2-immunoglobulin plasmid 5. chromogen Develops spots at end of ELISPOT Augments vaccine used on monkeys Pol p68A, Pol QV9, Env p41A Subpopulation of virus in the body Method measures response to epitopes
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