ADAPTIVE INMUNE SYSTEM Flashcards
Cellular inmunity refers to Inmunity mediated by
T-CELLS
Humoral inmunity refers to Inmunity mediated by
B-CELLS
Functions of Adaptive Inmune System
- Identification of SPECIFIC antigen and its destruction
- Inmune Memory for SPECIFIC antigen
- Clonal Expantion
- Lymphocyte repertorie
- Prevention of self-injury (Non-reactivity)
Clonal expantion stands for
A high number of Lymphocytes for a unique specific antigen
Lymphocyte Repertoire refers to
The sum of T-Cell and B-Cells RECEPTORS
Lympochytes with T-Cell Receptors are known as
T-Cells
T-Cell is in charge of _____________________ and are activated by ________
Cell mediated Inmunity / Via APCs
Where do T-Cells are born and where do they mature?
Born: Bone Marrow
Mature: Thymus
Final location of T-Cells
Spleen and Lymph Nodes
T-Cells can only identify Protein antigens located in ______
MHC Molecules
What is TCD4 cell?
T-Helper Cell
TCD4 cells bind to ________
MHC II
Activated TCD4 cells activates ___________
B-Cells and Cytotoxic T-Cells
What is a TCD8 cell?
T-Cytotoxic Cell
TCD8 cells bind to __________
MHC I
Activated TCD8 cells function
Kill infected cells by production of Granzymes and Perforins
What is a Regulatory T-Cell?
T-cell in charge of the down regulation of inumne response
What does a T-Cell receptor need for ACTIVATION
FIRST SIGNAL:
Binding of Antigen on APCs (TCR to MHC)
SECOND SIGNAL (Costimulatory signal)
Binding of CD28 (T-cell) and B7 (APCs)
The B7 receptor in APCs is also known as
CD 80/86
B-cells are characterized for containing ____________ on its surface
Antibodies
B-cells are in charge of
Humoral-mediated inmunity
How long do activation of B-Cell receptors take?
2-7 days
B-cells are produced in _________
Bone Marrow
B-Cells final destination once mature
Spleen and Lymphoid nodules
B-Cells only secrete Antibodies in response of
SPECIFIC ANTIGEN
B-cells that does not secrete antibodies are known as
Naive B-Cells
How is B-Cell receptor known?
ANTIBODY or INMUNOGLOBULIN
How does B-Cell activation occur?
1) B-Cells find a specific antigen and bind to it and charge it in its MHC II molecule
2) MHC II on B-Cells bind to TCR on TCD4 (FIRST SIGNAL)
3) CD40 on B-Cells bind to CD40L on TCD4 (SECOND SIGNAL)
Activated B-Cells functions:
- Production and secretion of Antibodies
- Classtype Switching
- Maduration for affinity
What is an Antibody?
Receptors on B-Cells (also called Inmunoglobulins) that identify and neutralize pathogens.
Antibody structure
Made of a Light Chain (L) and a Heavy Chain (H)
Regions in the Antibody
1) Constant Region (Fc): Determines TYPE OF ANTIBODY and BIND TO COMPLEMENT
2)Antigen-finding region (Fab): Unique and BIND TO ANTIGEN
Which region of Inmunoglobulins bind to complement?
Constant region (Fc)
Which region of Inmunoglobulins bind to antigen?
Antigen-Finding region (Fab)
What kind of antibodies there are?
Monomers: IgD, IgE, IgG
Dimers: IgA
Pentamers: IgM
Most abundant Inmunoglobulin in blood
IgG
IgG is produced by _________
Activated B-Cells
Function of IgG
- Fixes complement (Classical pathway)
- Opsonizes bacteria
- Neutralizes toxins and viruses.
Which Inmunoglobulin can cross the placenta?
IgG
IgA is primarily found in
MUCOSAL SURFACES and SECRETIONS to prevent colonization
Which Inmunoglobulin does not fix to complement
IgA
Where are IgM found?
Surface of B-Cells
Which is the first Antibody produced by inmature B-Cells?
IgM
Why in T-Cell affecting diseases there is only IgM?
Because lack of T-Cells mean no B-Cell activation = No class switching = Only IgM
Fc Region of IgE binds to
Mast cells and Basophiles
Exposure of IgE to Antigen produce
CROSS-LINKING and Release of inflammatory mediators
IgE is associated with ______ Hypersensitivity and is the defense mechanism against ___________
Type I / Parasytic infection
What is V(D)J Recombination?
Process that generates diversity of T-Cell and B-Cell Receptors
V(D)J Recombination needs:
- RAG 1
- RAG 2
- TdT
