Immunology Flashcards
which cells are part of the innate immunity?
macrophage, mast cell, natural killer cell, complement protein, dendritic cell, neutrophil, basophil, eosinophil
which cells are part of the adaptive immunity?
B cell, antibodies, cytokines, T cells
which cells are part of both innate immunity and adaptive immunity?
y-delta T cell and natural killer T cell
cytokines
proteins used for communication between cells
triggers immune response
interleukins (ILs)
type of cytokine
made by WBCs and acts on other WBCs
interferons (IFNs)
type of cytokine
coordinate responses to infections, activates NK cells and macrophages, protects uninfected cells, “interferes” with tumor growth
what parts of the body make up the innate/passive or non-specific immunity?
skin/mm, normal flora (commensal bacteria), lysosomes (digestive enzymes), inflammatory response to antigens: phagocytes, natural killer cells secrete perforin
what are natural killer cells?
a type of lymphocyte
attacks antigens without stimulation from another cell type
secretes perforin: cell will die, capable of responding within hours
leukocyte (WBCs) description
part of innate immunity
neutrophils: phagocytic, release of antimicrobial substances, live for a few days
eosinophils: antiparasitic proteins, work with basophils and mast cells in allergic responses
basophils: coordinate inflammation response, allergies and parasites
natural killer cell description
part of innate immunity
infected cells in body release interferon which activates NK cells to release more interferon
interferon protects uninfected cells
interferon “interferes” with tumor growth
NK cells locate and recognize abnormal cells without “learning”
macrophage description
part of innate immunity
monocytes: circulate for a few days, develop into macrophages, phagocytic
macrophages: sentinels, phagocytic, removes dead/damaged cells, present pieces of antigens to T lymphocytes
dendritic cells
part of innate immunity
related to monocytes, long branched cells like a tree
present information to T-cells to initiate adaptive immune response
can take 24-72 hours to activate T-cells
bridge between innate and adaptive immunity: relays important information about pathogen to T-cells to mount a protective immune reponse
mast cells
found on skin and connective tissue
sentinels: signals (cytokines) waiting to be activated
granules release histamine and heparin
receptors for IgE
allergic and inflammatory response
mast cell activation
direct stimulation: ex. bee sting, cold exposure
when exposed to antigen IgE is primed for the mast cells degenerate
histamine and heparin: causes vasodilation leading to edema, warmth, redness, attraction of other inflammatory cells to site of release
adaptive/specific immunity
bone marrow stem cells: B and T lymphs
1. humoral/specific immunity
2. cell-mediated immunity
primary immune response = 1st time antigen is encountered
secondary immune response = subsequent encounters
humoral/specific immunity
B-lymphocytes
antibody response
cell-mediated immunity
T-lymphocytes
cellular response (phagocytic)
B-lymphocytes
differentiate into plasma cells which produce antibodies
memory B cells: long lived, “remembers” antigens, faster responses
B cells mature in bone marrow or Bursa of Fabricus in birds before moving to secondary lymphoid organs (spleen and lymph nodes)
each B cell develops a specific receptor to a specific antigen and produces antibody clones to that antigen
immunoglobulins
antibodies
part of humoral immunity
bind to epitope of antigens
adjuvant: substance added to vaccines to enhance antigenicity
5 classes or isotropes
epitope
marker molecule
how do antibodies bind to an antigen?
each antibody has 2 Fab regions that bind to the antigen
Fc is a constant region and has unique functions for different Ab classes
IgM
largest antibody
primary immune response
activates compliment (classical cascade)
IgG
secondary immune response
most abundant in blood
neutralizes microbes/toxins
crosses placental barrier (passive transfer)
IgA
body secretions (tears, mucus, colostrum)
IgE
hypersensitivity reactions, coats cell for eosinophil
too much = damage to self (allergies, anaphylaxis)
IgD
surface of lymphocytes, acts as an antigen receptor for B cells
how are antibody isotypes categorized?
according to differences in their amino acid sequence on the Fc of antibody
antigen-antibody complex or immune complex
actual molecule created by bound Ag and Ab
can play a beneficial role in eliminating disease but can damage tissue in certain conditions
what cells are included in cell-mediated immunity?
T-lymphocytes and phagocytes
cell-mediated immunity function
macrophage engulfs pathogen —> presents piece of pathogen to T-cell —-> T-cell communicates with B-cells and produces cytokines —> activates antibody production and cell destruction
T-lymphocytes produced in bone marrow but develop in thymus
helper T-cells
CD4+
produce cytokines, activate B-cells, activate macrophages
killer T-cells
cytotoxic
produces substances that “pop” holes in damaged cells
how do helper T-cells and B-cells work together?
antigen present —> T helper cells produce cytokines to activate B-cells —> B-cell divides and differentiates into antibody clones
AIDS/FIV
virus attaches to T helper cell and decreases number of them as well as impacts cytokine communication
when numbers of these cells get to a certain low level it is considered AIDS
regulatory cell
CD25+
suppressor T-cells
keep system from getting out of control, autoimmune disease overwhelms suppressor cells
ANA: anti-nuclear antibody test
complement system
proteins that “compliment” inflammatory (phagocytes) and antibody response
lysis of cells
integral to innate and adaptive immunity, can be activated early in infection even before antibody response
has 3 pathways that produce a cascade of reactions once activated
opsonization
“tags” pathogens for destruction and phagocytosis
performed by complement system
what are the pathways of the complement system?
lectin and alternate pathways (innate immune response)
classical pathway (adaptive immune response: antibodies)
immune tolerance
self discrimination: as lymphs develop antigen receptors, they will develop them for the body’s own cells; in healthy animals the immune system discriminates between self and non-self
suppressor or regulatory lymphocytes: prevent self reactive lymphs from differentiating and proliferating
lymphoma
proliferation of lymphocytes
which disease is immunosuppression seen in?
seen in FIV
hypersensitivity type 1
type 1: mast cells (allergies-IgE-anaphylactic shock)
immediate hypersensitivity when chemical mediators from mast cells are released
hypersensitivity type 2
autoimmunity (IMHA)
antibodies directed against the animal’s own cells
hypersensitivity type 3
increased AG (immune complex disease)
antigen-antibody complexes formed that deposit in vessels
hypersensitivity type 4
cell mediated disease (in tissues)
ex: dermatitis, doesn’t involve antibodies
antigenic drift and shift
antigenic drift: mutations
antigenic shift: new strain created
