Adaptive Immunity: T cells, MHC, and Antigens Flashcards
What do active T cells have the ability to do?
Kill cells of the body that have been infected by viruses or bacteria, as well as cancer cells
Adaptive immunity
Activation and expansion of specialized lymphocytes
Hematopoietic stem cells
- WBC
- RBC
- Platelets
Primary lymphoid organs
- Thymus gland
- Bone marrow
What cells mature in the thymus gland?
T cells
What cells mature in the bone marrow?
B cells
Secondary lymphoid organs
- Peripheral lymph nodes
- Mucosa Associated Lymphoid Tissue (MALT)
- Spleen
Mucosa Associated Lymphoid Tissue
- Site of approximately 80% of all lymphocytes
- Initiates immune responses to specific antigens encountered along all mucosal surfaces
Largest mammalian lymphoid organ system?
Mucosa Associated Lymphoid Tissue
3 important characteristics of adaptive immunity are…
- Self recognition
- Specific
- Memory
MHC allows for…
Recognition between self and non-self antigens
Human Leukocyte Antigen System
Responsible for genetically encoding our cells in humans for recognition by the immune system as either self or non-self
All nucleated cells have…
MHC type I
What cells are not nucleated and do not have MHC I?
RBCs or platelets
MHC is or is not unique?
Is unique
What cells are antigen presenting cells?
- B cells
- Macrophages
- Dendritic cells
Purpose of memory cells?
For a more robust second encounter for the same pathogen
Epitopes
Different shapes on top of antigen, that antibodies attach to
What are the three types of lymphocytes?
- T cells
- B cells
- NK cells
T cell lymphocytes
Protect our bodies against cancer and infected cells by pathogens
Effector
Activated cell
NK Cells are produced…
In bone marrow and stay in bloodstream
NK uses
Pattern recognition
NK attacks by…
Inducing apoptosis
NK cells also help to activate what type of cells? Who do they go and activate?
Help activate macrophages, which go and activate T cells
Macrophages
Recruited to the area, phagocytosis
Dendritic cells
- Constantly taking information from around them through pinocytosis until it finds a pathogen then will phagocytose
- Antigen presenting cell
Antigen presenting cells gives the antigen to the…
T cell receptor
CD4 Helper T cells function?
Activate macrophages to effectively kill ingested microbial pathogens
Do CD4 cells kill any other cells?
No, only help
Once T cells help activate macrophages, what is then activated?
B cells
CD8 Cytotoxic T cells
Act on infected cells (by viruses) and directly kills them
Helper T cells are activated by the recognition of antigens on what type of MHC molecule?
MHC II
Helper T cells help activate what? How do they do this?
Activates inflammation by releasing cytokines
Helper T cells helps what kind of cell mature?
Help activate B cells to secrete antibodies
What type of cells do helper T cells activate?
Activate the cytotoxic T cells
What does CD8 release?
Perforin and granzymes
Perforin
Poke holes
Granzymes
Stimulate apoptosis
What MHC class does CD8 pair with?
MHC I
Do CD8 cells need antigen-presenting cells to identify non-self cells?
No, because they recognize our self cells
Naive T cells
Release by the thymus but has not matured yet until it encounters corresponding antigen
T regulatory/T reg
Suppresses immune response, prevents allergy and autoimmune disease
How do T reg cells suppress the immune response?
- Anti-inflammatory cytokine release
- Cell lysis of immune cells
- Blocking immune signaling
Memory T cells are formed with
Clonal selection
Memory T cell function
Protect body from future invasion of the same antigen
Steps for form memory T cells or more effector cells
- Naive T cells finds dendritic antigen presenting cell, T cell is activated, activated T cells are cloned
- Either creates more effector cells or memory T cells
T cell receptors have…
Has antigen binding sites that are specific
How many types of T cell receptors are there?
2
Interleukins
Group of cytokines
How many T cells in the thymus do not enter circulation?
98%
TH1
- Direct all out response against intracellular pathogens
- Also activates CD8
TH2
Directs restrained containment response against chronic disease and extracellular parasites
TH17
- Directs response against extracellular microorganisms
- Bacterial and fungal
