Chapter 14
Which of the following statements is/are true regarding viral delivery for gene therapy? To be marked correct, you'll need to select all applicable statements, as there may be more than one correct answer.
-Adenoviruses are less likely than retroviruses to integrate into a host genome, providing less potential for gene editing. -Engineered adenoviruses and retroviruses are the most common viruses used in gene therapy.
Fluorescent antibodies are also used in immunofluorescence assays
.
Western blotting and complement fixation assays are immunodiagnostic techniques that less common in clinical settings.
.
In the practice of variolation, how were patients exposed to the smallpox pathogen?
.They were exposed to dried scabs from smallpox lesions.
Which of the following statements concerning vaccinations correct?
.Vaccinations stimulate immunological memory, allowing for a strong secondary response.
How long before vaccine reaches peak of protection
2 weeks
Advantages that immunological diagnostics have over biochemical testing include except
detection of an organism that has not been previously identified.
While performing an ELISA, a lab technician fails to rinse away unbound detection antibody from the wells before adding the substrate for the reporter enzyme What is the likely outcome of this error?
All wells, including controls, will indicate a positive result
Two adjuvants approved for inclusion in routine vaccines
Aluminum salts Monophosphoryl lipid
How are vaccines catgorized
By how they are made
flow cytometry.
Cells can be stored by this method relies on FACS
fluorescence-activated cell sorter (FACS).
Counts tagged cells and sorts then from nontagged
Innactive vaccines are stable at room temp why is this a plus
Easy to ship and store Also they are noninfectious making them safe for immune compromised patients
Who discovered the method of vaccination
Edward Jenner
ELISA
Enzyme-linked immunosorbent assays
The risk of a vaccine for an immunocompromised individual is higher for inactivated vaccines than for live attenuated vaccines.
False
Interferon gamme release assays
Fast and reliable way to detect TB in the early stages
plaque reduction neutralization test
In this test the patient's serum is extracted from a blood sample and seri- ally diluted. Next, a purified preparation of the suspected virus is added to the various tubes of diluted serum. Each serum/virus mixture is then added to separate petri plates of cultured cells and incubated for a few days. If the serum lacks antibodies to the virus then the virus infects the cultured cells at a level similar to controll sample
variolation
In variolation, the practitioner blew a powder made from the dried scabs of smallpox lesions into a healthy individual's nose. The resulting smallpox infections tended to be milder
Who developed early version of rabies vaccine
Louis Pasteur
How was vaccination discovered
Milkmaids infected with cowpox became immune to smallpox
For best results in an enzyle linked immunosorbent test the detection antibody should be ...
Monoclonal antibody
Conjugate vaccines
Practice of linking polysaccharides to a protein antigen to generate immunogenicity
Which of the following statements provides the best definition for the term herd immunity?
Provided that a sufficient percentage of the rest of the population is vaccinated, non-vaccinated individuals, such as premature babies and immune- compromised patients, have protection against various diseases.
Human Immunodeficiency Virus-1 (HIV-1) is an RNA virus with a long incubation period. Due to the long time needed for disease symptoms to develop, disease progression can alternatively be measured by detection of HIV genetic material in the bloodstream of infected patients. Which of the following molecular methods would be most appropriate for disease detection of HIV-1 in patient's bloodstream?
Reverse-transcriptase polymerase chain reaction
Which of the following statements concerning restriction enzymes is true?
Some restriction enzymes generate overhangs in the target DNA sequence upon digestion, whereas other restriction enzymes perform blunt cuts.
Herd immunity
The fewer disease-susceptible people in a community, the harder it is for a pathogen to be transmitted to a susceptible host who could then spread the disease
Double immunodiffusion test
This gel diffusion test is useful for testing a patient sample for diverse antibodies or antigens all at one time.
Radial immunodiffusion test
This test helps to quantify the amount of a particular antigen present in a sample.
Which of the following statements concerning adjuvants is true?
The precise mechanisms that adjuvants use to increase immunogenicity are not yet understood, adjuvants may stimulate cytokine release and encourage antigen uptake and processing by antigen-presenting cells
Which of the following statements regarding immunoprecipitation reactions is true?
The zone of equivalence in an immunoprecipitation reaction is the area where there is an equal or roughly equal amount of antigen and antibody molecules.
The more closely a vaccination agent resembles the actual infectious agent, the more likely a strong adaptive immune response will be elicited.
True
What has caused an outbreak of vaccine preventable diseases
a drop in childhood vaccination rates
A major factor in the re-emergence of vaccine-preventable diseases in the early 21st century has been
a flawed research study incorrectly linking vaccination to autism was published in the late 1990s.
How is recombinant vaccine made
a gene that encodes a protein antigen (such as a viral surface protein) is inserted into a cell that will make large quanti- ties of the protein-usually a bacterial mammalian cell culture line is used for this purpose. The desired protein is then harvested and purified for inclusion in the vaccine.
fear of vaccinations re-erupted because of what
a paper published in The Lancet (a medical journal) described a study of just 12 patients and claimed a correla tion between the measles, mumps, and rubella (MMR) vaccine and the develop- ment of autism.
A DNA vaccine involves placing genes into a plasmid and introducing the plasmid into human cells. Human cells then transcribe and translate the genes to produce antigen which immunize the recipient. What is the source of the genes being introduced?
a pathogen
Drawback of attenuated vaccines
agents in them could cause disease in an immune-compromised host. can mutate to an infectious form and cause disease.
Direct ELISA
allows for identification of antigen in a sample
Agglutination tests make use of the fact that
antibodies have two antigen-binding sites and will cause clumping when bound to antigen
monoclonal antibody
antibody that recognizes just one epitope of particular antigen.
How can a non vacinated person put someone who is at risk
any time an agent causes an infection, it has the potential to mutate and render our current vaccines and/or drugs ineffective, putting vaccinated people at risk
Live attenuated vaccines
are the closest to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen
zone of equivalence
area where there is an equal or roughly equal amount of antigen and antibody molecules
agglutination reactions typically used for what ?
blood typing, to identify infection, and identify noninfectious immune disorders
complement fixation assays
detect patient antibodies in a serum.
Inactivated vaccines
consist of whole inactivated pathogens, such as killed bacteria or inactivated viruses, or parts of pathogens.
Live attenuated vaccines
contain pathogens that have been altered so that they do not cause disease (are not pathogenic), but are still infectious.
whole-agent vaccines
contain the entire pathogen, which has been rendered inactive by heat, chemicals, or radiation.
How are attenuated agents developed
cultivating the pathogen in cell culture in such a way that it loses its pathogenicity or by genetic manipulation.
Reverse transcription PCR is used specifically to
detect the presence of RNA viruses.
polymerase chain reaction (PCR)
detect viral genetic material
Genome mapping
documents the position of every nucleotide, provides a blueprint for the proteins and regulatory RNAs produced by a cell, and may reveal the presence of "pathogenicity islands as well as information about genes for basic cellular functions.
how many binding sites does each antibody have
each antibody molecule has two antigen binding sites
Taq polymerase
enzyme from the hot springs bacterium Thermus aquaticus;
Recombinant vector vaccines
genetic material from the pathogen is packed inside a harmless virus or bacterium, which is then introduced into the body
main benefit of live attenuated vaccines
is that these vaccines are the closest to the actual agent encountered in nature
centrifuge
machine used to remove serum from blood by spinning at high speeds
gel electrophoresis.
molecules are separated based on their size. Because electrophoresis can take several hours,
For vaccination to be effective they must...
must stimulate immunological memory without causing the disease they aim to protect against.
adjuvants
pharmacological additives that enhance the body's natural immune response to an antigen. Required in subunit vaccines
The aspect of the immune response that vaccines are based on is
production of memory cells and high antibody titers from pathogen exposure.
Toxoid vaccines
protein toxins. can be purified and inactivated to make a class of subunit vaccine
immunogenic
proteins on a pathogen stimulate an immune response
Western blotting
protocol that detects specific proteins in a sample,
immunofluorescence microscopy,
protocol where fluorescent-tagged antibodies that recognize a specific antigen incubated with tissue or cell samples, followed by observing the sample with a specialized microscope.
recombinant vaccines.
purified from a genetically engineered expression system
three main groups of subunit vaccines
purified subunit vaccines, toxoid vaccines, conjugate vaccines
Most common antibody precepitation methods
radial immunodiffusion test and double immunodiffusion test
indirect ELISA.
requires two antibodies. The first antibody recognizes the antigen bound at the bottom of the plate wells and the second antibody is linked to an enzyme and serves as the detection antibody
sandwich ELISA
requires two antibodies: a capture antibody and a detection antibody
Which aspect of the polymerase chain reaction (PCR) is mismatched with its description?
template DNA: the DNA to be copied; must be present at a igh concentration for the procedure
benefit of whole-agent vaccines
the agent is essentially the same as what would be encountered in nature, but they can't cause disease in a weak host or mutate to cause disease
The technique of vaccination as developed by Jenner was an improvement over variolation because
the cowpox virus used by Jenner was not fatal to humans but provided protection against smallpox.
Plaque reduction neutralization tests are based on the fact that
the presence of antibodies in a patient's serum will prevent viral infection of cells in culture
Plaque reduction neutralization tests are based on the fact that
the presence of antibodies in a patient's serum will prevent viral infection of cells in culture.
Serology
the study of what is in patients serum
Cons of inactivated vaccines
their lack of infectivity also means they are quickly cleared from the body, which limits exposure to the antigens
A drawback of all inactivated vaccines is that
they are quickly cleared from the body, limiting antigen exposure
Subunit vaccines
they consist of purified antigens or parts of the infectious agent.
goal of serology
to determine if patient has certain antigens and/or antibodies in their blood.
vaccinate
trigger the body's immune response against infections
reverse transcriptase
used in conjunction with primers to build DNA that is complementary to RNA molecules in a sample.
Reverse Transcription PCR (RT-PCR)
useful for detecting RNA in a sample-such as the genome of an RNA virus.
Immunoprecipitation reactions are used for what?
useful for determining what antibodies or antigens are present in a patient's sample.
real-time PCR
uses fluorescence imaging to visualize DNA copies as they are made
DNA vaccines
vaccine approach is to use a pathogen's DNA to stimulate an immune response.
seroconversion period
weeks between infection and the production of antibodies
agglutination
when antibodies bind antigens into a clump
DNA microarrays reveal
which genes are being expressed in a given cell.
