Week 3 Flashcards
Antibodies AKA ______, are glycoproteins produced by plasma cells that help protect the body from foreign invaders called antigens.
Immunoglobulins
Name the five classes of antibodies: 1) ___ 2) ___ 3) ___ 4)___ 5)___
IgA, IgD, IgE, IgG, and IgM
The two heavy chains in antibodies are connected at the juncture via _____.
2 disulfide bonds
____, AKA Antigen binding fragment, where the arms of the Y are involved in antigen recognition.
Fab region
The lower base of the Y is involved in important biological activities of the antibody; it is named the crystallizable fragment ____.
Fc region
True/False: In antibodies, the heavy chains are called so, because they have a higher molecular mass than the light chain.
True.
Five heavy chains that represent the five different antibody classes: ___ (IgA), ___ (IgD) ___ (IgE) ___ (IgM) ___(IgG)
Alpha (IgA) delta (IgD) Epsilon (IgE) Mu (IgM) Gamma (IgG)
The three regions of the antibody 1) ____, 2) _____ and 3) _____
1) Antigen binding fragment Fab region 2) Crystallizable (Fc) region, 3) Hinge region
How does the Fab region recognize the unique antigen?
Together the two variable domains in the upper portion of the Fab create a pocket, so to speak, with a unique conformation that will accommodate the shape of its antigen.
The unique secondary structure of the variable region _______, actually creates the binding pocket.
Beta-pleated sheet
The unique amino acid sequence of the _______ determines the shape of the binding pocket at the Fab region.
Complementary determining regions (CDRs)
What region of an antibody is responsible for antigen recognition?
The antigen-binding fragment (Fab) region is responsible for antigen recognition.
True/False: The Fc region participates in antigen recognition.
False Comprises the bases of two heavy chains, responsible for the individual class functions of an antibody NOT for antigen recognition.
True/False: The Fc region has only constant domains.
True
What region of an antibody is responsible for complement fixation?
The Fc region is responsible for complement fixation.
____, is the unique amino acid sequence of the constant domains within an individual.
Allotype
_____, refers to the unique sequence of amino acids that composes the variable domain of the antibody. Determines the specificity of an antibody for its antigen.
Idiotype
Antigen binding Affinity vs. Avidity
Affinity is the strength required for an interaction between an antigen and a specific antigen binding site on the antibody.
Avidity is the binding between the antigen and the entire antibody molecule, not just a single site. More sites equals more avidity.
True/False: IgM has higher avidity for an antigen than IgG because its 5 monomers can associate with more antigens than IgG’s monomer.
True. IgM associates with 10 antigens (2 antigens per monomer x5)
IgG is a monomer, associating with only 2 antigens.
Mnemonic: The different classes of antibodies: _______
MADGE IgM IgA IgD IgG IgE
IgA exists as a dimer in the mucosa and a monomer in the blood. Its main function is ______.
Mucosal immunity
IgD exists as a monomer and is mainly involved in ______.
B-cell signaling
IgE is a monomer involved in ________ and _______.
Allergic reactions and Helminth defense
IgG is a monomer, most abundant, and crucial in the later stages of _______ to infections.
Immune response
IgM is a ______. Plays a major role in the early stages of the immune response to infections.
Pentamer.
What class of antibody can exist as a dimer?
IgA, but only mucosal surfaces. It’s a monomer in the blood.
IgE is found as a monomer on the surface of _____ and _____.
Mast cells and basophils
True/False: IgG is the predominate antibody of the late immune response.
True
Which class of antibody is generated earliest in an immune response?
IgM is generated first in the immune response. Later the body switches to producing primarily IgG.
___ antibodies are the most numerous antibodies in the serum and their main role is to serve as opsonins.
IgG
The only class of antibody that does not need T cells to be produced is ____.
IgM
___ antibodies are found on mature B cells and serve as a signal that they are ready to leave the bone marrow.
IgD
___ antibodies can be found in large quantities in breast milk.
IgA
The first immunoglobulin made in response to an infection is ____.
IgM
The alternative pathway of complement activation is considered to be part of the (innate/adaptive) _____ immune system because it is independent of antibody interactions.
Innate
The membrane attack complex compromises the integrity of microbial plasma membranes leading to (reversible/irreversible) ______ cell injury.
Irreversible
C3b and C4b are complement proteins that serve as _____ and enhance phagocytosis.
Opsonins
Anaphylatoxin activity in the complement cascade is regulated by ______ which cleave C3b and C5a.
Carboxypeptidases
C3 and C5 ____ are the enzyme components that cleave the complement components C3 and C5 respectively.
Covertases
_____ is a serine protease that cleaves C3b into inactive fragments.
Factor I
C3a and C5a are complement proteins known as ________ because they induce an increase in capillary diameter and attract other cells to sites of tissue damage.
Anaphylatoxins
The classical pathway of complement activation is considered part of the (adaptive/innate) _____ immune response because it is initiated by immune complexes.
Adaptive
____ is the complement protein that initiates the classical pathway of complement activation.
C1q
_____ refers to a collection of serum proteins that connects the innate and adaptive immune systems.
Complement
What is the goal of VDJ Rearrangement?
To create a massive amount of unique antigen receptors for T and B cells.
What is the gene that recognizes self-reactive B cells?
AIRE gene expressed in primary lymphoid tissue
B cells differentiate into _____ when they encounter an antigen at peripheral lymphoid tissue.
Plasma cells
In the fetus, the primary location of B-cell development is in the ____.
Liver
___ and ___ are two immunoglobulin isotopes expressed on the surface of mature naive B cells.
IgM and IgD
Immature B cells leave the bone marrow, becoming transitional B cells and complete the maturation process in the ____.
Spleen
____ is a lymphocyte characterized by CD19, CD20, CD21, and CD40 cell surface proteins.
B cell
(Pre/Pro/Immature) _____ B cells undergo negative selection.
Immature B cells
Negative selection meaning killed or inactivated.
The most important marker on B cells is CD___.
CD19
During B-cell development, a hematopoietic stem cell become a ___ cell.
Pro-B cell
The Pre-B cell checkpoint checks if the ______ is on the cell surface, and if it is not the cell undergoes apoptosis.
Pre-B cell receptor
The presence of ______ on B-cell receptors allow B cells to leave the bone marrow.
IgD constant region
B cells are positive for major histocompatibility complex class(es)?
MHC I and II
The ____ is the most abundant lymphocyte in a normal person.
T cell
___ is a type of T cell that MHC I binds to.
CD8+ T cell
The ___ is type of lymphoblast that can express CD2, CD3, CD4, CD5, CD6, CD7, CD8, and CD28 receptors.
T cell
___ is a type of lymphocyte associated with acute and chronic organ rejection.
T cell
_______ is a type of T cell that functions to maintain specific immune tolerance through the suppression of CD4+ and CD8+ T cell effector function.
Regulatory T cell
Once the naive B cell finds its antigen, it binds to it and is activated, becoming an ______.
Effector B cells OR a plasma cell
True/False: Unlike T cells, B cells can bind to antigens freely circulating in the blood.
True
Most antigens bound to B cells do not fully activate the cells. Full activation requires the B cell to bind a _____.
CD4+ helper T cell
Which immunoglobulin’s main function is to initiate the complement system?
IgM
What kind of plasma cell does IL-4 induce B cells to become?
IgE plasma cells
____ are special B cells whose goal in life is to remember this specific infection and then later become activated in a “quicker and better” fashion and fight it off.
Memory B cells
What two cell types does an activated B cell produce?
A plasma (effector) cell and a memory B cell
The T-cell dependent pathway relies on T cell receptors recognizing ____ antigen protein complexes on the surface of ____.
MHC II, B cells
True/False: Post-transcriptional processes like Alternative splicing do NOT affect DNA sequences as DNA recombination does.
True
True/False: In the process of ubiquitylation, you NEED a lysine residue in the substrate protein.
True
The growth factor for Hematopoietic stem cell is _____.
Stem cell factor (SCF or c-kit ligand)
Also, what is the receptor called for the Hematopoietic stem cell growth factor?
Tyrosine Kinase membrane receptor or c-kit
Do Lymphoid Progenitor cells give rise to cells like Neutrophils, Dendritic cells, and macrophages?
No. They give rise to T cells, B cells, and Natural Killer cells.
What is the factor that stimulates Neutrophil production?
Granulocyte Colony Stimulating Factor (G-CSF)
Where in the body can you find mature B cells?
Circulation of blood, lymph, and peripheral lymphoid organs (ex: spleen)
