Adaptive Immunity Flashcards
Explain cell mediated immunity
-cells that are infected present antigen to cytotoxic T cells (this activates them)
-cytotoxic T cells can destroy cells by perforin
Or by….
Macrophages present to T-helper cells that activate cytotoxic T cells
Explain humoral immune response
- macrophages consume the pathogen and then present the antigen on the surface
- this then binds to helper T cell
- this then stimulates a B cell (B cells can also be activated by free antigens)
- B cells make antibodies that deactivate the pathogen
- these antibodies can also signal to macrophages to get them
Memory T cells can….
Activate cytotoxic T cells to go after infected cells
Memory B cells…
Has a memory of the antigen, activates plasma B cells that then produce antibodies
Where do B cells originate and mature?
In the bone marrow
B cells are ______ in blood and lymph.
When exposed to the pathogen they multiply and become _______ cells, and then _________.
Naive,
Effector cells,
Memory B cells
Is cellular or Humoral defenses associated with T cells?
Cellular defenses
Is humeral or cellular defenses associated with white blood cells and antibodies?
Humoral
What would happen if cells lost MCH 1?
Natural killer cells would poke it
What are phagocytes in the immune system?
Neutrophils
Monocytes) —-> macrophages (macrophages can do it over and over again unlike neutrophils
What are the antigen presenting cells? And what MCH class are they?
Dendritic cells, B cells, macrophages
MCH class two
Can helper T cells kill directly?
No but they activate cells that deal. They raise the alarm to tell other immune cells there is a problem. The release cytokines that activate T cells and finish training of the cells
Can cytotoxic T cells kill cells?
Can kill cells by granzymes and perforans
This is another type of effector cell. Tell other immune cells to stand down when the initial threat is handled
Regulatory T cells
Humoral is ________ mediated. B cells/ _______cells
Cell mediated involves ____ cells
Antibody
Plasma cells
T
What are the attributes of adaptive immunity?
- unresponsiveness to self
- specificity
- inducible
- clonality
- memory
Protein or polysaccharide on or in cells and viruses
Epitope or antigenic determinate
What is an antigen?
Substance perceived as foreign that can stimulate a response by T & or B cells
This is an antigen that has the potential to induce immune response. They are so small that they usually do not induce an immune response on their own. If engulfed and presented on a cell it would then be large enough to activate an immune response
Haptens
What factors influence antigenicity/immunogenicity?
- foreigness
- size of dose/threshold does
- size of antigen
- Chemical composition
- physical form
- degradability
How do you cells differentiate cell from non-self?
MHC major histocompatibility complex (integral membrane proteins)
human leukocyte antigen (HLA) complex
Group of jeans on chromosome six. Important in determining histocompatibility
On the surface of all nucleated body cells. Allows for regeneration of self and regulate immune reactions against all tissues of the body. Unique to person
Endo or exo?
MHC-1
Comes from inside the cell (endo)
On antigen presenting cells (macrophages, dendritic cells, B cells) presentation of antigens on these antigen presenting cells to these T cells
Not RBC
Exo or endo?
MHC-2
Exo (outside the cell)
Proteins that are involved in the complement system includes red blood cells
MHC- 3
B cells differentiate into ______ cells which is full of rough ER to synthesize proteins/antibodies
Plasma
MHC1 binds to antigen peptides that originate in cytoplasm and present antigen to …
CD8 T cells
MHC 2 binds to antigen fragments that come from outside cell and present to….
APC’s= macrophages, dendritic cells,
and B cells
CD 4 T helper cells
Response to each individual epitope is clonal, meaning….
Gives rise to a population of cells that originate from a single cell and are clones
What happens when a B cell is stimulated?
Generate plasma cells that secrete antibodies against the antigen
Humoral immune response requires several cell types and ________ interactions
Cell-to-cell
Cross-reactivity to similar epitopes can happen, what is an example?
Cowpox and smallpox
Discovered by Edward Jenner
Describe the structure of immunoglobulins
- Glycoproteins
- two functionally distinct fragments (FAb fragment: variable regions of heavy and light chains)(hyper variable region, the site on antibody where epitope binds)
- Fc fragment: Constant region
Four polypeptide chains connected by disulfide bonds
Glycoproteins
The site on the antibody were the epitope binds
Hypervariable region
Determines isotype
Binds cells, antibodies and molecules of immune system (complement)
Fc fragment
We can synthesize _____ different unique antibodies
10^11
Antibody diversity attributed to combinatorial joining (5 million) in the human germ line
- _________ aka hypermutation
- _________ at the junctions of VJ and VDJ
Somatic mutation
Recombinantorrial splicing
Shared by all members of a species
Isotypes
Shared by some, but not all members
Allotypes
Changes within the same antibody class, in the same individual
Idiotypes
75% or 20% of all plasma proteins, main isotype class in the blood
- monomer
- two binding sites
- in blood, length, and intestine
- Fix compliment, opsonin, neutralize toxins in viruses, may cross placenta protecting fetus and newborn
IgG
What is the second antibody isotype to respond?
IgG
4 (as dimer) or 2 as monomer
- 15-20% serum antibodies
- mucosal protection, in tears, milk, saliva, mucus
- only antibody isotype found in breastmilk
IgA
- pentamer in serum, monomer on B cells as a receptor
- in blood, in length, and on B cells
- first antibody produced (first to respond)
- can activate the classical pathway
IgM
- not well understood antibody isotype
- in blood, in length, and I’ll be sauce. Tends to buy into mass cells at the Fe region
- BCR, innate immune responses on B cells
IgD
- found on mass cells, basophils and in blood
- acute hypersensitivity/allergic reactions, lysis of parasitic worms
- antibodies are secreted by plasma cells, they do not directly kill they eliminate or inactivate the target
IgE
How do you antibodies eliminate/inactivate their targets?
- neutralization
- opsonization (antibodies place tag on it, to signal that phagocytes need to come)
- oxidation
- agglutination
- complement activation
- ADCC(when bound to the target it activates other cells like natural killer and eosinophils to come in and kill) final reaction
B cell development begins and ends in __________ (hematopoiesis)
Red bone marrow
B cells are primarily in …
Spleen, lymph nodes, and MALT
The cells differentiate into _________ and __________.
Antibody producing plasma cells
Memory cells
Humoral immune response to antigen occurs when…
The antigen is recognized by the host’s B cells for the first time
During a secondary exposure immune response, secrete more _____ than ____
IgG, igM
T independent antigens:
Antigens stimulate the cells to make only ____
This is weaker than T dependent response
IgM
-doesn’t include maturation response that leads to class switching Poor memory induction to T independent antigens
T- ___________ : antigens presented on MHC 2 to T helper cell
- most protein antigens are of this type
- t-helper cells produce cytokines activate activate B cells
- all antibody types produced
T- dependent
What cells are the link between humoral and cell mediated immunity?
T cells
They respond to intracellular pathogen‘s and abnormal body cells
What are the locations of T cells?
Begin development in red bone marrow and completed in time is gland. Localized in secondary lymphoid tissue
Mature T cells are naïve until….
Once activated proliferate into ________ cells and _______ cells
They are activated by antigen presentation
Requires MHC recognition
Effector cells and memory cells (clonal expansion)
-all produce cytokines with a spectrum of biological effects
What do cytotoxic T cells do?
- kills infected or cancerous host cells
- upon activation cytotoxic T cells leave lymph node and find host cells presenting same antigen
Where does T cell education in deletion occur?
What does negative selection test for?
Thymus
Self tolerance (If T cell binds to strongly or binds south MHC that isn’t presenting antigen, or presenting self antigen, it will fail negative selection —-> apoptosis -it should only weekly bind to Self MHC presenting foreign antigen
_________ cells Block activation of harmful self reactive lymphocytes. They prevent auto immune disease
Regulatory T cells
All nucleated cells have MHC one, and can be killed by _____ cells
Cytotoxic T cells
Of the four types of hyper sensitive reactions which ones are cell mediated and which ones are antibody mediated?
Type 1-3 are antibody mediated
Type 4 is cell mediated
Type of hypersensitivity reaction
- results from a release of inflammatory molecules often called allergy
- immediate
Type one (immediate)
Associated with mast cells, basophils, and eosinophils
Explain the process of a type one hypersensitivity reaction
- B cells are activated in differentiate into plasma cells
- release IGE antibodies
- bind to FC receptors on the surface of mast cells
- degranulation – a Denteley cyclase
- mass cells release granules causing allergies
Type of hypersensitivity reaction
-due to IgG and IgM (complement)
Ex?
Type two cytotoxic reactions
Ex: blood type incompatibility, transfusion reactions, hemolytic disease of newborns
Type of hypersensitivity reaction
- antibodies to soluble antigens, immune complex reactions
- injection of antiserum
- Recruit neutrophils
Type three hypersensitivity
Ex: lupus, arthritis, Arthrus
Type of hypersensitivity reaction
- delayed delayed, cell mediated immunity response
- involved with tissue transplants
- hapten is presented on the cells surface to cytotoxic T cells
Type four hypersensitivity (delayed)
Tissue transplant from one part of the individual to another part…
Transfer between identical twins…
Autograft
Isograft
Tissue Transferred from same species…
Tissue transplant from a different species..
Allograft
Xenograft
