NTRODUCTION TO IMMUNOLOGY, MHC & ANTIGEN I Flashcards
Substance capable of
stimulating an immune
response, whether humoral
or cell-mediated, or both
leads to immune response
immunogen
Substance recognized
by the immune system;
serves as target of an
immune response
does not necessarily lead to an immune response
antigen
directly stimulate B cells to produce antibodies
polysaccharides (bacterial capsule)
t-independent
T-dependent
requires help of CD4+T cells to stimulate antibody production
usually proteins
T-dependent
molecule that is not immunogenic by itself but can react with specific antibody
a low MW substance which by itself cannot stimulate immune response
hapten
Antigenic determinant
Actual molecular structure that interacts with a single antibody
molecule or T cell receptor
epitope
region recognized by immunoglobulins
3-20 amino acids or sugar residues
b-cell epitope
Region recognized by T cell receptor
8 – 15 amino acid residues long
Recognized by T lymphocytes only after being processed and
presented in association with an MHC protein
b-cell epitope
Substance, which when mixed
with an antigen, enhances the
magnitude and duration of the
immune response
adjuvan
TWO MAJOR PHAGOCYTIC LINEAGE
M
P
mononuclear phagocytes
polymorphonuclear granulocytes
TWO MAJOR PHAGOCYTIC LINEAGE
Remove particulate matter of foreign origin (e.g. microbes) or self-origin (e.g. aged RBC)
mononuclear phagocytes
Monocytes express _______ and ________ MHC molecules
can present antigens to helper T cells
with pattern recognition receptors
CD14 and Class II MHC molecules
TWO MAJOR PHAGOCYTIC LINEAGE
With pattern recognition receptors
Play an important role in acute inflammation
Phagocytosis and destruction of pathogens
polymorphonuclear
granulocytes
TYPE OF POLYMORPHONUCLEAR GRANULOCYTES
multi lobed nucleus
acute inflammation
majority of bacteria especially pyogenic microorganisms
neutrophils
POLYMORPHONUCLEAR
GRANULOCYTES
mediates tissue damage in type I hypersensitivity (allergy)
release chemicals (major basic protein) that kill parasitic worms and their eggs
present antigens in vitro
eosinophils
AUXILLARY CELLS
allergy or type I hypersensitivity
secretions: heparin, histamine, chondroitin, proteolytic enzymes, and cytokines
play a role in parasitic infections
basophils
AUXILLARY CELLS
functionally similar with basophils but not mobile circulating cells
lie close to blood vessels in all tissues
mast cells
AUXILLARY CELLS
cell fragments derived from megakaryocytes in bone marrow
with granules, microtubules and actin/myosin filaments/ clot retraction
platelets
AUXILLARY CELLS
Link innate and adaptive immunity
Take up and process antigens for recognition by T cell
produce cytokines
antigen presenting cells
DENDRITIC CELLS
__________: process and present foreign protein antigens to T Cells
___________: passively presents immune complexes to B cells in lymphoid follicles
classical dendritic cells
follicular dendritic cells
___________
Located in epidermis
Carry antigen from skin and mucosa to the TH cells
Migrate via afferent lymphatics into paracortex of draining LN called interdigitating DCs
rich in class II MHC molecules
Langerhan’s cells
Natural Killer Cells/NK Cells/Null Cells/Large Granular Lymphocytes
Innate host defense; 10 – 15% of lymphocytes in
circulating blood; functional NK found in spleen
lymphocytes
Adaptive, cell-mediated immunity
60-80% of circulating lymphocytes in the body
includes T helper cells and Cytotoxic T cells
T lymphocytes or T cells
type of T lymphocytes
stimulate differentiation of B cells into plasma cells
activate cytotoxic T cells
T helper cells
type of T lymphocytes
virus infected cells. tumor cells, and foreign cells (e.g. tissue grafts)
cytotoxic T cells
________ or (B cells)
adaptive, humoral immunity
differentiate into plasma cells
cell surface contains
Immunoglobulins (IgM, IgD)
Class II MHC molecules
receptors for C3b (CD35), and C3d (CD21)
B lymphocytes
__________________ –
recognition of self and non
-self (peripheral tolerance);
suppress excessive
immune response
used by CD4+CD25 regulatory t cells
immune surveillance
