Lecture 9 (exam 3) Flashcards
(26 cards)
What is the pathway of pathogen entrance to clearance? 1-5 steps
1-pathogens enter via mucosal surfaces (lungs, intestines, skin)
2- pathogen detected by resident phagocytic cells —> triggering innate immunity
3-free pathogen & some phagocytic cells eat the pathogen flow or migrate thru lymph vessels —> to secondary lymph structure (lymph structure)
4-intersect with lymphocytes, entering the blood
5–adaptive immunity is initiated in the secondary lymphoid structures, where T helper cells, T cytotoxic cells and B cells proliferate
What is pathways of pathogen enterance thru clearance? Steps 6-8
6– T and B cells migrate out of the lymph node
7– as they identify areas of infection migrate toward the infection—-> help and destroy remaining pathogens ( effector phase)
8— memory cells are generated
How do we generate immune cells? What are stem cells defined by?
Hematopoiesis —-> HSCs differtiate into mature blood cells—> myeloid and lymphoid
Ability to regenerate & ability to differentiate into divers cell types
What are the types of innate myleoid cells?
Granulocytes—-> mast, eosinophils, neutrophil, basophils (MENB)
Phagocytes—-monocytes, macrophages, dendritic cells
What do granulocytes do?
What do they do when activated?
First responders to pathogens—> like bacteria & worms
Release contents of granules (direct & indirectly impair pathogenic activity)
Release cytokines that allow adaptive immune response (contribute to allergic reactions)
what are phagocytes activated by?
Where are macrophages found?
What are the most potent?
Actived by antigen—> can activation T cell lymphocyte
In all tissues
Dendritic—->antigen presenting cells for naive T cells
What do lymphocytes include? (Lymphoid lineage)
B and T cells
What do B cells do?
What do they express on their surface ?
What do they ultimately differentiate into?
Main player in adaptive immune response—> source of immune memory
Antigen receptor—> BCR
**Activated B cells can present antigens to T cells
Antibody producing cells —-> called plasma cells
What do Tcells do?
What receptor?
What are examples?
Adaptive immune response—> immune memory
TCR receptor
CD4 helper—> recognize peptides bound to MHC class 2
CD8 cytoxic —> recognize peptides bound to MHC class 1
What are natural killer cells?
What cell type & immunity?
Can recognize cells lacking?
Defend against virus, bacteria, and tumor cells
Lymphocytes—> participates in innate immunity
Łyse cells lacking MHC class 1
Where do B cells develop?
What do they produce & structure?
Bursa of Fabricus
Develope in bone marrow
Antibodies & immunoglobin structure
Where do T cells develop?
What are the 2 kinds?
Thymus
Helper cd4
Cytoxic CD8
What type of stem cells are dendritic cells?
What do they do?
Both myeloid and lymphoid
Activate T cells as APC (antigen presenting cells)
Bridge innate immunity & adaptive
What are the 3 phases of immune responses?
Which are innate and which are adaptive?
Innate, early induced, and late
Innate—immediate and early
Adaptive—adaptive response
What is the pw of immediate?
Infection—> recognition by non specific effectors—> remove agent
What is the pw of innate response?
Infection—> recruit effector cells—-> recognize PAMPS (activation of effector cells)—>remove agent
What are the stages of late response?
Infection—>
transport of antigens to lymphoid
organs— >
recognition by naive B and T cells—>
clonal expansion & differentation—> removal
What are characteristics of innate immunity?
Cells involved?
Depends on?
How does it protect?
Immediate & constitutive
Myeloid cells, NK cells, complement
Ability ot distinguish molecules expressed by microbes
Neutralization or destruction of non self structure
Characteristics of adaptive immunity?
Types of cells?
Depends on?
Delayed & inducible
T and B cells
Diversity with the specificity of the receptors on B and T cells
Makes memory cells & responses
What are the 2 different types of pathogen recognition methods by immune cells?
Pattern detection: recognize—> innate cells—> innate immunity
Antigens specific: recogniztion—> adaptive cells —-> adaptive immunity
What cells express pattern recognition receptors for discrimination between self and non self?
Neutrophils and macrophages— innate
What are antimicrobial agents produced by phagocytes after taking up stuff?
Acidification
Toxic oxygen products
Toxic NO
Antimicrbial peptides
Enzymes
Compeptitors
What is clonal selection?
Individual lymphocytes are activated to produce a clone or deleted to prevent a clone from developing
What are 4 main principles that define clonal selection?
Lymphocyte expresses single antigen specifity
Recognition of that antigen results in lymphocytes activation
Activation—-> proliferation of that lymphocyte & form a clone ( all have same antigent specificity)
Self reactive lymphocytes are deleted during developement & not present in circulation
