Microbiology chapter 15 part 2
The following steps occur during the B-cell response to T-dependent antigens. Place them in the correct sequence, starting with the earliest at the top.
1. B cell receptor binds to antigen 2.b cell internalizes antigen 3. B cell degrades antigen into peptide fragments 4. Peptide fragments are presented on MCH class 2 molecules Th cell recognizes antigen fragments and activates cell.
What are the basic functions of helper T cells?
Activation of macrophages Activation of B cells Coordination of activities of B cells, macrophages, and other T cells
What are B cells responsible for
Antibody response
The term "Fab region" stands for "fragment of __________binding region."
Antigen
The main function of the lymphatic system is to allow to interact with ____________and activate lymphocytes
Antigens
Cytotoxic T cells (Tc cells) induce ______ in infected self cells and cancerous cells.
Apoptosis
Antibody-antigen binding can activate the complement cascade via the ______.
Classic pathway
The portion of antibody molecules that has a consistent amino acid sequence regardless of the epitope recognized is referred to as the __________ region
Constant
______ gather antigens using pinocytosis, phagocytosis, and sending tentacle-like extensions between epithelial cells to mucosal surfaces.
Dendritic cells
Most antigens are T- blank meaning that T-helper cells are required for confirmation.
Dependent
The process of antibody__________cellular cytotoxicity (ADCC) relies on IgG antibodies binding targets, allowing NK cells to bind to their exposed Fc regions.
Dependent
True or false: IgM is the main circulating antibody in the bloodstream.
False
True or false: Macrophages cannot function to eliminate antigen without assistance from helper T cells.
False They can function to eliminate antigen, but they do so more efficiently when they have been activated by helper T cells.
There are ________general types of constant regions that correspond to the major classes of immunoglobulin (Ig, aka antibody) molecules.
Five
The human immune system produces five main classes of antibodies. What are they?
IgD IgG IgA IgM IgE
IgG is the only antibody that is transported across the ____________into the fetus's bloodstream.
Placenta
Differentiated B lymphocytes that produce antibodies are called
Plasma cells
Which type of antigen is most common?
T-dependent
True or false: IgG accounts for approximately 80-85% of total antibody in the serum.
True
An antigen is a molecule capable of interacting with ______.
a B-cell receptor an antibody molecule '
Clonal selection is a critical theme in the adaptive immune response. The two main features are that ______.
a population of lymphocytes able to recognize a functionally limitless variety of antigens is generated each lymphocyte recognizes and responds to only a single epitope
When a macrophage receives assistance from a helper T cell in the form of cytokines, it ______.
activates more potent destructive mechanisms for the cell, enhancing its antigen clearing capacity
Helper T cells orchestrate the immune response by ______.
activating B cells and macrophages directing the activities of B cells, macrophages, and T cells
Before a B cell undergoing antigen-induced activation can proliferate, it must usually get help from ______.
another type of lymphocyte--a helper T cell (TH).
The presence of ______ can initiate the classical pathway of complement activation.
antibodies bound to antigen
The receptor on the surface of B cells is most similar to a(n) ______.
antibody molecule
Cells that produce MHC class II molecules are collectively referred to as ______.
antigen-presenting cells
The variable region on an antibody molecule is found ______.
at the end of the Fab regions
The function of the two arms of the Y-shaped antibody molecule is to ______.
bind to epitopes, or antigenic determinants
The lymphatic system's primary role is to _______.
bring antigens into contact with lymphocytes, allowing activation, proliferation, and differentiation of specific B and T cells into effector cells
What do T cells do
cellsInteract with target cells and then cause changes in those cells
The cell types that produce MHC class II molecules for exogenous antigen presentation include ______.
dendritic cells macrophages B cells
The basic functions of effector cytotoxic cells (TC cells) include ______.
destruction of cancerous self cells induction of apoptosis in infected self cells
Clonal selection is a critical theme in the adaptive immune response. The two main features are that ______.
each lymphocyte recognizes and responds to only a single epitope a population of lymphocytes able to recognize a functionally limitless variety of antigens is generated
Dendritic cells gather material by ______.
extending tentacle-like extensions between epithelial cells to mucosal surfaces phagocytosis pinocytosis
The major classes of immunoglobulin molecules correspond to the _______.
five general types of constant regions.
The cells that have the general role of interacting with target cells and then inducing changes in them are ______.
helper T cells cytotoxic T cells
The basic functions of effector cytotoxic cells (TC cells) include ______.
induction of apoptosis in infected self cells destruction of cancerous self cells
A T-cell receptor (TCR) is ______.
is similar (but not identical) in function to a B cell receptor is found on the surface of T cells only recognizes antigen that is presented by another cell
IgM ______.
is the first class of antibody produced during a primary response to an antigen
The clonal selection theory states that there are ______.
many lymphocytes produced, but each has only one specific epitope it will react with
A B cell in a lymph node is a(n) ______ type of lymphocyte, while a plasma cell is a fully ______ lymphocyte.
mature but naive; differentiated
An antigen interacting with a T-cell receptor ______.
must be broken down into peptide fragments and presented on an MHC molecule
All of the following are true of antigen processing and presentation in B cells EXCEPT ______.
peptide fragments are loaded into B cell receptor molecules for presentation to helper T cells
Dendritic cells gather material by ______.
phagocytosis extending tentacle-like extensions between epithelial cells to mucosal surfaces pinocytosis
When a helper T cell recognizes a peptide presented by a B cell or macrophage, it will ______.
secrete cytokines that will assist in the activation of the B cell or macrophage
