Adaptive immunity Flashcards
Define cell mediated immunity
- involves activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
- doesn’t involve antibodies.
- T-cells
Define humoral immunity
- involves antibodies B-cells.
What are the 2 cells involved in adaptive immunity?
Where do these cells develop?
How are these cells transported across the body?
Where do these cells reside?
- B & T cells (lymphocytes).
- both develop in primary lymphatic tissue e.g. red bone marrow.
- transported in lymph vessels.
- can reside in secondary lymphatic organs e.g. spleen & lymph nodes.
Where do T cells mature?
- T-cells mature in thymus.
Where do B cells mature?
- B-cells mature in the bone marrow.
What is the MHC? What is its role? What cells is it on?
- Major Histocompatibility Complex.
- involve with recognition of pathogens by B&T-cells.
What does the MHC bind to?
- peptide proteins, antigens, non-self material (and self).
Where is MHC 1 found? What pathogen is it used to detect? What immune cell does this recruit?
- MHCI = all nucleated body cells (not RBC).
- detect virus.
Where is MHC 2 found? What do these cells do?
- MHCII = antigen presenting cells (B cells (some t-cells), dendritic cells, macrophages).
What type of cell produces antibodies?
- plasma cells
Sketch and label an antibody
- see example
What do antibodies bind?
antigens of pathogens or foreign bodies in the blood, lymph or tissue.
What happens when a b cell binds a pathogen antigen? What chemicals are involved? What cells aid this?
- this activates the B-cell causing them to proliferate and differentiate into plasma or memory B-cells.
- t-helper cells, interleukin-4&6 encourage this .
What are the effector cells of this b cell pathway?
- plasma cells.
What enables the body to “remember a pathogen”?
- memory cells are long lived and contain specific antibodies (epitope) that will react in the case of a reinfection.
What are the 4 things an antibody can do?
- neutralise antigens, toxins.
- immobilise bacteria, prevent flagella or cilia movement.
- Agglutination, easier to be engulfed by phagocytes.
- activates the complement system.
What is the primary antibody produced? What are properties of this? What is the secondary and properties?
- IgM - less specific and titre is small.
- IgG - very specific and secreted in high amounts.
What are the types of T cell? What does each do?
- Cytotoxic killer cells: bind to MHCI complex and use CD-8 protein to form perforin and granzymes to lyse the infected cell.
- Helper t-cells: bind to MHC-TCR complex. this causes activation to produce memory t-cells (clonal selection).
they also produce cytokines and interleukins to stimulate B-cell activation.
How are T cells activated? What costimulation is needed?
- binding to MHC using T-cell receptors (TCR) and costimulation from interleukin-2.
What do T helpers bind to MHC Class ____ on the surface of APCs. They use ____________ to bind to the MHC-TCR complex. _________ also occurs and the cell is activated. ______________________ is the term used for proliferation and production of memory T cells.
-2, CD-4 protein, costimulation, clonal selection.
Active T cells produce ________ to stimulate _________ and other _________________ which costimulate the activation of B cells.
- cytokines, phagocytosis, interleukins.
What do cytotoxic T cells do? What MHC do they bind? What protein do they use to form a complex?
- elimination.
- Class I.
- CD-8 protein.
How do T cells eliminate infected cells (2)? Describe the chemicals involved
- apoptosis: release granzymes - digest proteins inducing apoptosis - any microbes release after are killed via phagocytosis.
- cytolysis: perforin & granulising from granules inside cell.
perforin is inserted = channels & granulising = holes - lyses membrane - fragments - phagocytosis.
How are T cells controlled for self-tolerance? Where?
- Thymus
- tests to see if self MHC complex is bound to - if so KILLED.
What occurs if T cells are not controlled for self-tolerance?
- autoimmunity - body attacks itself.
How are B cells controlled for self-tolerance? Where?
- bone marrow.
- test to make sure they don’t attack self MHC or antigens.
___________________ is the term used to describe proliferation of selected cells. And active and memory T cells are produced.
- clonal selection
