immunology final-quizzes

Terms in this set (39)

Which is the best definition of immunity?
The state of being resistant to reinfection with a pathogen
PAMP stands for
pathogen associated molecular pattern
2 main early theories were proposed to explain how antigen-specific antibodies develop
Instructional theory, Selective theory
Instructional theory
False; Antigen receptors on lymphocytes adapt to configuration of the antigen during an immune response
Selective theory
Mostly correct; Proposed by Ehrlich; Lock and key: antigen receptors are specific for different antigens. Exposure to the antigen would induce production of more of that antigen receptor. Where he was wrong was assuming that each lymphocyte carried multiple receptors. This model was fine-tuned with clonal selection theory, which stated that any one lymphocyte has only one antigen receptor
Variolation
less lethal form of small pox was rubbed into skin. This didn't work. The expected results were that the individual would contract a weak form of small pox and the immune system would be strengthened.
Edward Jenner made an advancement from variolation.
He suggested that people should be inoculated with cowpox, and they would subsequently develop immunity to smallpox.
How do memory cells develop?
Correct: T cells and B cells from the primary response persist and become reactivated.
Which of the following BEST describes chemokines?
Correct: Soluble proteins that recruit specific cells to an area.
What is the name of the multipotent stem cell that gives rise to all blood cells?
Hematopoietic Stem Cell
Describe briefly what immune tolerance is, and how it is normally generated.
Tolerance is a mechanism for ensuring that the immune system does not react to selfantigens, which would lead to severe damage (autoimmunity; autoimmune diseases such as type I diabetes, lupus, rheumatoid arthritis, inflammatory bowel disease result in part from loss of tolerance). The primary mechanism is during lymphocyte development; autoreactive lymphocytes (those that recognize self antigens) undergo apoptosis. (We haven't discussed it yet, but there are other mechanisms for inducing tolerance to some non-self antigens, including members of the indigenous microbiota, mothers recognizing fetus, and some others).
Which of the following cell types is responsible for the secretion of immunoglobulins?
Correct: Plasma cell
Naïve lymphocytes enter the lymph nodes via which of the following structures?
Correct: high endothelial venules
Describe opsonization.
Opsonization is a process in which pathogens that have been coated by antibody or some complement components are better recognized by phagocytes than they are without such coating. This will lead to enhanced phagocytosis. a. Some notes here: The phagocyte is not opsonized; rather the pathogen/antigen is. Also, opsonization enhances recognition by phagocytes, of which macrophages and neutrophils are the best examples. b. B and T cells (lymphocytes) do not recognize opsonized objects better, and are not phagocytes. c. Be sure you understand terms like phagocyte, monocyte, lymphocyte, lymphoid cells, myeloid cells etc.
The group of secondary lymphoid tissues that includes the tonsils, adenoids, Peyer's patches are collectively referred to as
Mucosal Associated Lymphoid Tissue.
Receptors that are multivalent tend to bind to their ligands more strongly than receptors with a single binding site. What is the term used to describe this phenomenon?
Correct: Avidity
Which of the following isotypes of antibodies is the largest?
Correct: IgM
Although the cytokine response is not specific in the way that antigen-antigen receptors are, the response provoked by cytokine expression is often very fine-tuned, affecting a limited number of cells. Describe briefly one process that helps restrict the cytokine response to a smaller number cells.
Autocrine signaling can limit the signaling process to just one cell. The same cell sends the signal and also receives the signal. You could have described directional secretion (reorganization of the MTOC to secrete cytokine only in the direction of an adjoining cell), short half-life of cytokines, cell-specific expression of cytokine receptors (or up/downregulation of regulation) and a few more.
Which of the following is the correct relationship between PRRs, PAMPs, pathogens, and macrophages? (blank) on (blank) recognize (blank) on (blank).
Correct: PRRs (pattern recognition receptors); macrophages; PAMPs (pathogen-associated molecular patterns); pathogens
Which cytokine is known for its induction of the anti-viral protein response?
Correct: IFN-α (interferon-alpha)
C-reactive protein is a/an:
Correct: acute phase response protein
How do natural killer cells kill their targets?
Correct: by inducing apoptosis
Which of the following would you predict to result from a mutation in TLR-4 (Toll-like receptor) that prevents binding to LPS (Lipopolysaccharide)?
Correct: decreased susceptibility to septic shock
To which of the following is MBL (mannose-binding lectin) most structurally similar?
Correct: C1q
Which of the following complement fixation pathways can be initiated by a soluble C3 convertase?
Correct: Alternative
At what stage of T cell development is the pre-TCR expressed?
Correct: DN
In negative selection, cells that receive (blank) signal through their antigen receptors die.
Correct: a strong
The self renewing B cells that originally developed from fetal hematopoietic tissues, and which reside primarily in the peritoneal and pleural cavities, are called (blank) B cells.
Correct: B-1
For a naïve T cells to become activated signal 1 (recognition of MHC/peptide and CD3 signaling is not sufficient). CD80 or CD86 (B7.1 or B7.2) on the APC must also interact with (BLANK) on the T cell to deliver a second signal.
Correct: CD28
Refer to above question- If a T cell only receives signal 1, and does not receive signal 2, the T cell goes into a nonresponsive state called (blank).
Correct: anergy
Which cells that are found within germinal center light zones are generally NOT found in the GC dark zones?
Correct: FDCs (follicular dendritic cells)
To which compartment in the body can long-lived plasma cells potentially be retained for the lifetime of the individual?
Correct: bone marrow
The function of somatic hypermutation is BEST described by which of the following statements?
Correct: increasing the affinity of immunoglobulins for their antigen
Which of the following antigen types could be characterized as TI (T-independent) antigens?
Correct: bacterial cell wall components and capsular polysaccharides
Which of the following is the correct sequence of events? Assume the APC is a dendritic cell.
Correct: antigen uptake, antigen processing, APC migration to lymph nodes, antigen presentation
After production, naïve lymphocytes travel briefly through the blood to the:
Correct: spleen, peripheral lymph nodes, mucosal associated lymphoid tissue
Which of the following types of hypersensitivity reactions is associated with IgE?
Correct: Type I hypersensitivity
Name on of the primary mast cell granule products released during a type I hypersensitivity response.
Correct: histamine
What would would be a medical reason to see high concentrations of IgE in non-allergic individuals?
Correct: worm infection
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