Term
How are adaptive immune responses initiated? |
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Definition
When the antigen receptors of lymphocytes recognize antigens |
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Term
List examples of macromolecules recognized by B lymphocytes |
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Definition
Proteins, polysaccharides, lipids, nucleic acids |
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Term
B cell mediated humoral immune responses may be generated against many types of ______ and _______ |
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Definition
B cell mediated humoral immune responses may be generated against many types of microbial cell wall and soluble antigen |
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Term
Most T lymphocytes only see peptide fragments of ______ and only when these peptides are presented by___________ |
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Definition
Most T lymphocytes only see peptide fragments of protein antigens and only when these peptides are presented by specialized peptide display molecules |
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Term
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Definition
It functions as the peptide display molecules of the immune system |
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Term
What does MHC restriction mean? |
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Definition
It refers to the property of T cell, in which different clones of T cells can see peptides only when these peptides are displayed by individual's MHC molecules |
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Term
What 2 things does T cell receptors recognize? |
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Definition
Residues of peptide antigen and MHC molecule |
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Term
What type of cell is necessary to activate Naive T lymphocytes? |
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Definition
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Term
After capture by professional APCs, where do the protein antigens of microbes go? |
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Definition
They are concentrated in the peripheral lymphoid organs |
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Term
Name the main 3 ways microbes enter the body |
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Definition
Skin, GI, Respiratory tract |
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Term
The professional APCs that are found in the epithelia are of which lineage? |
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Definition
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Term
IN the skin, epidermal dendritic cells are called_________ |
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Definition
IN the skin, epidermal dendritic cells are called Langerhans Cells |
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Term
Lymph node captures antigens from ____ and ______ |
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Definition
Lymph node captures antigens from epithelium and connective tissue |
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Term
Blood borne antigens are captured by APCs in the ________ |
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Definition
Blood borne antigens are captured by APCs in the spleen |
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Term
How does dendritic cells capture the antigens of microbes that enter the epithelium? |
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Definition
By phagocytosis and pinocytosis |
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Term
How does epithelial dendritic cells mature? |
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Definition
TNF and IL-1 ,secreted by macrophages and epithelial cells that have encountered microbes, cause the dendritic cells to round up and lose their adhesiveness for the epithelium. |
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Term
How do mature dendritic cells reach the lymph nodes? What path does it take? What occurs as it travels? |
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Definition
By chemokines normally produced in the T cell-rich areas. Travels via lymphatic vessels. Matures into APCs capable of exciting T lymphocytes by expressing more MHC molecules |
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Term
How many times do every naive T cells in the body cycle through some lymph nodes each day? |
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Definition
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Term
After a microbial antigen has been introduced to the body, how long does is approximately take for T cells to respond? |
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Definition
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Term
Name the most potent APCs for activating naive T lymphocytes |
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Definition
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Term
What are the 2 functions of dendritic cells? |
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Definition
Initiate T cell responses, and influences the nature of the response |
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Term
What cells play a role in cross presentation? |
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Definition
Professional APCs ingest infected cells and display the antigens present in the infected cells for recognition by CD8 T lymphocytes |
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Term
Can individuals with identical MHC locus accept grafts? |
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Definition
Yes, they will not reject it. |
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Term
Human MHC proteins are called ___________ |
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Definition
Human MHC proteins are called Human Leukocyte antigen |
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Term
The peptide binding cleft in MHC Class I and II are found in ________ |
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Definition
The peptide binding cleft in MHC Class I and II are found in amino-terminal end |
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Term
What part of the Class 1 MHC molecule forms the peptide binding cleft? |
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Definition
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Term
What part of the MHC class 1 molecule is polymorphic ( amino acids that differ among different individuals)? |
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Definition
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Term
Which domain of the MHC class 1 molecule is invariant and contains the binding site for the T cell co-receptor CD8? |
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Definition
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Term
Class 2 MHC molecule consists of what chains? |
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Definition
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Term
Why can only Class I MHC molecules present to CD8 T cells? |
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Definition
Only MHC class 1 contains the alpha 3 chain which is needed to present to CD8 T cells |
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Term
IN class 2 MHC, which 2 chains form the peptide binding cleft? |
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Definition
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Term
What is the difference between Class 1 and 2 peptide binding clefts? |
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Definition
Class 1 accommodates peptides of 8 to 11 Amino acids Class 2 accommodates peptides of 10 to 30 amino acids |
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Term
What chains are polymorphic in Class 2 MHC? |
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Definition
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Term
IN class 2 MHC, which chain contains the binding site for the T cell coreceptor CD4? |
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Definition
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Term
What is the reason CD4 T cells only respond to MHC 2? |
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Definition
Because MHC 2 has the Beta 2 chains |
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Term
What is the reason CD4 T cells only respond to MHC 2? |
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Definition
Because MHC 2 has the Beta 2 chains |
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Term
How are MHC genes expressed? |
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Definition
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Term
MHC molecules are not induced by what? |
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Definition
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Term
Which cells express Class 1 MHC? |
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Definition
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Term
Which cells express class 2 MHC? |
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Definition
Professional APCs like dendritic, macrophages, B-cells |
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Term
What fits into the MHC pockets and is responsible for anchoring the peptides in the cleft? |
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Definition
side chains of amino acids of the peptide antigens |
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Term
MHC molecules are said to have a _____ specificity for peptide binding |
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Definition
MHC molecules are said to have a broad specificity for peptide binding |
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Term
Peptide binding to the MHC clefts has a _____ and a ______ |
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Definition
Peptide binding to the MHC clefts has a low affinity and a slow off rate |
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Term
When do MHC molecule acquire their peptide cargo? |
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Definition
During their biosynthesis and assembly inside cells |
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Term
Class 1 MHC molecules acquire peptides from where? Class 2? |
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Definition
Class 1: Cytosolic proteins Class 2: intracellular vesicles |
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Term
What happens to MHC that do not acquire peptides to display? |
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Definition
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Term
Where in the cell are MHC made? |
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Definition
Endoplasmic reticulum of APCs |
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Term
Newly synthesized class II MHC have what in their peptide binding clefts? |
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Definition
CLIP, Class 2 Invariant Chain Ceptide |
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Term
What removes CLIP from Class 2 MHC? |
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Definition
Class 2 like protein called DM in the endosomal vesicle |
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Term
What is responsible for bringing the antigenic peptides to the newly synthesized MHC 1? |
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Definition
Transporter associated with antigen processing (TAP). Pumps antigen peptides into the ER lumen |
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