Mar21 M2-Adaptive Immunity 1 Flashcards
concept of biological medications and how they work in general (for Crohn’s, asthma, etc.)
slow or block the immune system
main actions of T lymphocytes
- coordinators of immunity and make cytokines
- anticancer**
- antiviral action
- antiTB action
- cytotoxic action
main actions of B cells
- produce abs
- produce cytokines
- present antigens**
how B and T cell change once exposed to an antigen
their progeny will change its Rs so that it has better affinity to the antigen (but the cell itself doesn’t do that tho)
how innate vs adaptive recognition of antigen differs
innate: patterns (lipopolysaccharides (LPS), viral DNA or RNA, etc.).
adaptive: specific peptides + can change recognition to make it better (the clone of B and T cells)
mucosal immune responses mechanism
- cold or allergy or invader destroys mucosa
- invader picked by surveillance cells (often dendritic cells) and presented to B and T cells in lymph nodes
(IMPORTANT) what T cells receptors recognize
peptides (broken down, native form of the protein. not the invader itself)
MHC class 1 found on what cells and interacts with what
all NUCLEATED cells of the body. MHC class 1 recognized by CD8+ T cells. ALWAYS on cell surface.
MHC class 2 found on what cells and interacts with what
found on APCs. present antigen to CD4+ T cells.
7 APCs in the body
monocytes, macrophages, B cells, dendritic cells, Langerhans cells (skin), Kupffer cells (liver), astrocytes (brain)
dendritic cells: how they recognize foreign substances and recognize what else
- with TLRs 1 to 11
- also recognize antibody coated antigens and complement coated antigens
dendritic cell goal
engulf and digest antigens to make them peptides and show them to T cells
what dendritic cell does at same time as it digests antigenic peptide to present it on MHC class 2
- becomes activated
- produces cytokines to help activate T cells like IL-12 and IFN-gamma
MHC class 1 vs class 2 when they’re on cell surface
- class 1 only on surface where there’s an invader
- class 2 always there. will present an antigen if there is one.
how MHC class 1 works to present an antigen
- viral invaders and other pathogens degraded in PROTEASOME
- MHC 1 + peptide complex together (assembled) in ER
- exported together to plasma membrane in a vesicle
how MHC class 2 works to present an antigen
- MHC 2 complex assembled in ER
- exported in acidic environment in endosomic vesicle
- pathogens degraded in same vesicle by acid + enzymes. peptide bind
reaction to allergen: what cell does the dendritic cell present antigen to
to CD4+ effector T cells in lymph nodes
WBCs distribution in the blood (%) and lymphocytes distribution
neutrophils 55% lymphocytes 33% (80% is T cells. 20% is B cells) monocytes-macrophages 5% band neutrophils 5% eosinophils 3% basophils 1%
biggest lymph node in the body + biggest collection of lymphocytes in the body
spleen
GIT biggest collection of lymphocytes
T lymphocytes recognition ability
- we’re born with limited repertoire of antigens that T cells can recognize
- exposure helps mature and refine the responses
lymphocytes mostly where in body
neck, tonsils, groin, spleen
lymph node vs peripheral B:T cells ratio
lymph node: 50-50
peripheral blood: more T cells (80%)
3 things T cells must have to recognize antigens + the one that’s a T cell marker
- CD3 (signaling complex) ***T cell marker
- CD4 OR CD8 (immature T cells have both)
- receptor for a peptide (TCR = T cell R)
one therapy knocking out T cells used in transplants to avoid rejection
anti-CD3 therapy. spleen recognizes T cells and removes them. get temporary immune deficiency that grows back
