Introduction to the Immune Respose Flashcards
innate immunity
- variety of mechanisms that can prevent infection or eliminate a pathogen
- present in all individuals at all times
- recognizes groups of similar pathogens (not antigen specific)
- not increased with repeated exposure to a pathogen (no memory)
examples of innate immunity
- physical barriers
- biologically active substances
- cellular
- skin
- mucous membranes
- lysozyme in tears or skin
- anti-microbial proteins
- cytokines induce fever
- activation of compliment
- natural killer cells
- phagocytes
macrophages
- large, mononuclear phagocytes tht are present in most tissues
- derived from blood monocytes
neutrophils
- phagocytosis and activation of bactericidal mechanism
- polymorphonuclear neutrophillic leukocytes
- major class of white blood cell
- enter infected tissue to engulf and kill extracellular pathogens
eosinophil
- killing of antibody coated parasites
- kills parasites that are too large to be pahgocytosed
- when activated they release substances that are toxic to helminths
basophils
- release of granules containing histamine
- found in the blood and thought to have a similar function to mast cells
mast cells
- release of granules containing histame
- found in CT
- involved in responses to parasites (helminths) and in the allergic response
natural killer cells
-can kill some virus infected cells and some tumor cells
dendritic cells
- antigen uptake in peripheral sites
- antigen presentation to T cells
- bridges the innate and adaptive immune responses
PRR
- pattern recognition receptors
- cells of the innate immune response have this
PAMP
- pathogen associated molecular patter
- the microbial product recognized by PRR’s
adaptive (acquired) immunity
- host defences mediated by antigen specific lymphocytes (B and T cells)
- includes the clonal expansion and differentiation of lymphocytes
- requires sensitization by antigen
- response is antigen-specific
- results in immunological memory
adaptive immune responses can be classified as
humoral or cell mediated
humoral immunity
- mediated by antigen specific antibodies produced by activated b lymphocytes (plasma cells)
- antobodies can be transferred to non immune recipients (naive) by immune serum (antiserum)
sell mediated immunity
- adaptive immune response primarily involving antigen specific T lymphocytes
- can be transferred to naive recipient by T cell, but not by immune serum
clonal selection results in
-the expansion of antigen specific b and T cell clones
proiferation and differentiation of memory cells
- a dingle progenitor cell gives rise to a large number of lymphocytes, each with a different specificity
- cells that recognize self are removed
- pool of naive lymphocytes remain
clonal selection of B cells
- antigen binding
- proliferation into a pool of memory cells and a pool of plasma cell clones which are Ab secreting
primary lymphoid organs in adults
- bone marrow (B cell development)
- Thymus (T cell development)
secondary lymphoid organs
- adenoid
- tonsil
- lymph nodes
- spleen
- peyers patches
multiple myeloma
- plasma cell tumor (neoplastic antibody secreting)
- the tumor cells are almost always derived from a single cell
- these cells will only produce one Ab, called a monoclonal Ab
- the lamignant cells hone to bone marrow and disrupt hematopoiesis resulting in lower white blood cell counts with increased susceptibility to infection and decreased RBC formation leading to anemia
gel of malignant myeloma
-see a large spike in gama globulin which is associated with Ab’s
antibody structure
- two long H (heavy) chains flanked by two short L (light) chains
- this is considered the monomeric form
- the H chains and L chains are identical for a given Ab
- a monomeric Ab has two identical binding sites
- a disulfide bond links the two heavy chains
papain
- proteolytc enzyme
- creates two Fab and one Fc domains from one Ab
- each Fab domain contains one antigen binding site
N term vs C term of an Ab
- N term is where antigen binding takes place, this contains the VH and VL variable regions
- C term is the constant region which only includes the H chains
light chain domains
- consists of one variable and one constant
- each domain is a stable structure and is known as Ig folding
