Adaptive immune system activation mastering Bio
What is the origin of the cytotoxic cells that attack other cells infected with a specific intracellular pathogen?
CD8+ T cells differentiate into cytotoxic T cells when they are activated by antigen-presenting dendritic cells, typically requiring cytokines released by activated CD4+ T cells. The cytotoxic T cells are deadly destroyers of invading pathogens.
How are cytotoxic T lymphocytes (CTLs) produced?
CD8+ T cells divide and differentiate into cytotoxic T lymphocytes. CD8+ T cells divide and differentiate into a clone of cytotoxic T lymphocytes.
Which of the following is a difference between class I and class II major histocompatibility complex (MHC) proteins?
Class I MHC proteins can be found on most cell types, whereas both class I and II MHC proteins are found on the antigen-presenting cells of the immune system
What is the final step in the cell-mediated response to a viral infection?
Cytotoxic T lymphocytes punch holes in the membranes of infected host cells. This step causes infected host cells to disintegrate and prevents the virus from spreading to other cells.
_____ interact with the antigen-class II MHC complex presented by macrophages.
Helper T cells Specific helper T cells recognize specific antigen-class II MHC complexes. The result of this is an activated helper T cell that stimulates both humoral and cell-mediated immune responses.
How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell?
Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies. Helper T cells recognize the receptor-antigen complex and activate the B cell, which divides and produces plasma and memory cells.
Concerning genes for MHC proteins, which individuals would you predict to be the healthiest?
Heterozygous Greater genetic diversity will allow a greater variety of peptides to be presented and recognized.
Which protein presents viral antigens on the outer surface of cells?
MHC protein. MHC proteins present antigens on the surface of infected host cells (cell-mediated response) or B cells (humoral response).
How is the cell-mediated immune response different from the humoral immune response?
The cell-mediated response involves cytotoxic T cells attacking other cells infected with an intracellular pathogen, while the humoral response involves B cells releasing secreted antibodies that bind to extracellular pathogens. The secreted antibodies bind to pathogens, preventing them from infecting additional cells and targeting them for phagocytosis.
What is clonal selection in lymphocytes?
The replication and persistence of B and T cells that have encountered the specific antigen match to their immunoglobulin receptor This is an important element of the "memory" of the immune system for some types of pathogens.
Why are antigen-presenting cells required for the differentiation of B cells into plasma cells?
They activate CD4 expressing Helper helper T cells. This is required for full activation of B cells.
Which structure is not a component of the adaptive immune system?
Tissues Lymphocytes of the adaptive immune system do not travel to tissues.
True or false? B cells were originally isolated from the bursa in chickens, and their function is to produce antibodies; T cells were originally isolated from the thymus in mice, and their functions include killing host cells that are being infected with a virus.
True
The major histocompatability (MHC) molecule is important in a T cell's ability to _____.
distinguish self from nonself
A cell type that interacts with both the humoral and cell-mediated immune pathways is a _____.
helper T cell
The activation of helper T cells is likely _____.
when an antigen is displayed by a dendritic cell
Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium?
macrophage Macrophages are phagocytic leukocytes.
If a patient is missing B and T cells, what would be absent from the immune response?
memory
If one was exposed to an antigen, and then exposed to a separate new antigen, what would likely occur?
A new primary immune response would occur. The response to the new antigen would be the same as the first.
A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over 20 years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell?
memory cell
Which of these cells is responsible for the rapidity of the secondary immune response?
memory cells Memory cells are responsible for the rapidity of the secondary immune response and for long-term immunity.
The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response.
perforin ... cell-mediated Perforin causes the lysis of pathogen-infected body cells; it is a component of the cell-mediated immune response.
Which of these cells produce and secrete antibodies?
plasma cells Plasma cells are clones of antibody-secreting B cells.
B cells that have been stimulated by interleukin-2 develop into _____.
plasma cells Plasma cells develop from B cells that have been stimulated by the interleukin-2 secreted by helper T cells.
Which of the following statements about the clonal-selection theory of immune system function is false?
Antigens are recognized by receptor proteins inside the lymphocyte. This statement is false; antigens are recognized by receptor proteins on the lymphocyte membrane.
Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____.
B cells ... plasma cells and memory cells The antigen-selected proliferation of B cells produces clones of plasma cells and memory cells.
Which of the following is associated with Class class II MHC?
Binds to CD4 This allows these Antigen antigen-presenting Cells cells to activate Helper helper T Lymphocytes-lymphocytes.
Which of the following is associated with Class class I MHC?
Binds to CD8 This allows it to interact with cytotoxic T cells.
