Fill-In-The-Blank: these statements are conceptual; as such there may be other correct answers in addition to the ones provided.
Lymphocytes that have not be activated by an antigen are often called resting or .
After an infection, a few antigen-specific T- and B-cells remain as lymphocytes.
are B-lymphocytes that pump out antigen-specific serum antibody.
Specialized mucosal immunity organs include the Peyer patches, , and .
Commensal bacteria make up our . Perturbations of this (e.g., through antibiotic use) can lead to .
Post-antibiotic overgrowth by C. Difficile bacteria can lead to .
Allergies, including food allergies, are often caused by the inappropriate production of antibodies.
A primary role of immunity is to regulate innate immunity.
Age-related involution of the reduces the number of naive T-cells over time, leading to .
T-cells slow down immune reactions and help prevent the development of diseases.
The injection of pre-made antibodies is called immunization.
Mass produced antibodies are often referred to as antibodies, or when used to treat diseases, .
a.k.a. leads to the development of active immunity.
Artificial PAMPs found in vaccinations are known as .
Multiple Choice Questions:
1) Monoclonal antibodies can target cancer cells that express a specific target antigen. Which of the following classes of proteins do you think make the best targets? (p.s. we didn't cover this in lecture!) Surface Receptors Nuclear Transcription Factors Mitochondrial Proteins Lysozomal Enzymes
Explanation: Unfortunately antibodies are far too large to get across the cell membrane of living cells, so they can only target surface proteins.
2) A rare genetic disorder prevents patients from producing regulatory T-cells. These patient die in infancy of: Cancers Infections Autoimmune Diseases Anemia
Explanation: When activated, T-regs inhibit immune responses. They play an important role in preventing autoimmune diseases.
3) You are treating a patient with early symptoms of Covid-19; you suspect the patient's symptoms will worsen over the next few days. Which of the following treatments would be of the most use: Monoclonal antibody against Covid-19 (passive immunity) Covid-19 vaccination (active immunity) Chloroquine (too soon??) Plasmapheresis (to remove existing serum antibodies)
Explanation: Passive immunity can provide immediate immunity against a pathogen. Active immunity (vaccination) takes weeks/months to develop.
4) Interestingly, patients who have received the diphtheria / pertussis / tetanus (DPT) vaccination can be asymptomatic carriers of any of those three diseases, and potentially able to infect non-vaccinated individuals (diphtheria and pertussis). What is the most likely reason: The vaccines are actually against the toxins these bacteria produce, rather than to the organisms themselves The efficacy of the vaccination declines over time Vaccinating for 3 diseases rather than just 1 decreases immune effectiveness The vaccine has a short shelf life and its efficacy declines as it approaches its expiration date
Explanation: DPT vaccinates agains the toxins that make a patient sick, they don't necessarily prevent a patient from becoming asymptomatically infected.
5) Dysbiosis refers to... The ejection of phagocytosed and digested debris from a phagocyte The inhibitory effect of regulatory T-cells Perturbations in our microbiome The binding of antibody to antigen
Explanation: Microbiome perturbations, particularly in the gut can cause dysbiosis.
6) Which of the following ONE OR MORE are true about IgA: Promotes the retention of commensal (beneficial) bacteria (our microbiome) Inactivates pathogenic bacteria with the gut lumen Leads to food allergies
Explanation: IgA both promotes commensal bacterial growth and inhibits pathogenic bacteria. IgE is the antibody primarily responsible for food allergies.
7) Pseudomembranous colitis, an overgrowth of the harmful bacterium C difficile in the gut... Is primarily the result of antibiotic use Is an example of symbiosis Is an example of a subclinical infection that does not typically stimulate an immune reaction All of the above
Explanation: Pseudomembranous colitis is a severe inflammatory reaction to dysbiosis typically caused by antibiotics that kill off our commensal microbiome.
8) RoGAM, the reagent given to prevent Rh disease (erythroblastosis fetalis) provides... Passive Immunity Active Immunity Both
Explanation: RoGam is an anti-Rh factor antiserum which confers passive immunity
9) Systemic mastocytosis is a rare disorder where mast cells proliferate. In severe forms, patients bone marrow can become packed with mast cells. In such cases, which TWO of the following do you think patients suffer from: Pancytopenia (decreases in the number of all leukocytes in the blood) Selective neutropenia (decrease in the number of neutrophils, but normal numbers of other leukocytes) Gammaglobulinemia (increases in the amount of antibody protein in the blood) Elevated levels of histamine
Explanation: Since the bone marrow is the birthplace of all leukocytes, bone marrow packed with any type of cell that doesn't belong there cannot effectively produce leukocytes resulting in pancytopenia. Since mast cells produce histamine, these patient can have systemically elevated amounts of histamine, which can lead to severe hives or even anaphylactic shock. We will talk about anaphylaxis in the next lecture.
10) Herd immunity refers to... (we didn't cover this, but it is worthwhile knowing) Immunizations given to beef cattle to prevent their being infected with pathogens The percent of infectious individuals within a population required to spread a disease The percent of immune/immunized people required to prevent a disease from spreading
Explanation: Herd immunity is dependent upon the number of people that are immune to infection, either by being infected or through immunization. The required percentage depends upon the infectiousness of the pathogen.