chapter 21 part B Flashcards
specific defensive system that eliminates almost any pathogen or abnormal cell in the body
- amplifies inflammatory response
- activates complement
- must be primed by initial exposure to specific foreign substance
adaptive immune system
recognizes and targets specific antigens
specific
not restricted to initial site
systemic
mounts an even stronger attack to “known” antigen (second exposure)
memory
two main branches or adaptive system
humoral (antibody mediated)
cellular (cell mediated)
- antibodies, produced by lymphocytes, circulate freely in body fluids
- bind temporarily to target cell (mark for destruction by phagocytes or complement)
- extracellular targets
humoral immunity
- lymphocyte act against target cell
-directly- kill infected cells (cytotoxic, NKC)
indirectly- release chemicals that enhance inflammatory response, or activate other lymphocytes/macros (tag em)
-CELLULAR tagets
cellular immunity
substances can mobilize adaptive defenses and provoke an immune response - target all adaptive immune response -usually seen as nonself complete/incomplete -antigenic deteminants -self antigen
antigens
incomplete antigen
-has to bin to protein or some part of us to attack
hapten
- can come in and start fuckin shit up
-immunogenicity
-reactivity
ex; pollen
complete antigen
immunogenicity
ability to come in an fuck shit up, able to stimulate proliferation
ability to react with activated lymphocytes and antibodies released by immunogenic reactions
reactivity
haptens
- involve molecules that are too small to be noticed alone, so they have to bind to us to become antigenic
ex; poision ivy, danders or gordy
-not complete till it attaches to us
-combo of protein and hapten is then seen as foreign
incomplete antigen
part of antigen that antibodies/ lymphos receptors bind to
- multiple factors to determine that antigen
- multifaceted
antigenic determinants
all cells covered w variety of proteins located on surface that are not antigenic to self, but may be antigenic to others in transfusions or grafts
-ex; blood transfusion and BC don’t match, my immune system will attack donor blood, creates widespread coagulation. self antigen was not evident, body regect, body attack
self antigen
important self proteins are a group of glycoproteins called______
the flagpole, flag is the self fragment
-displays the self fragment
-contain grove that can hold piece of self antigen or foreign antigen
- t lymphocytes can recognize only antigens that are presented on MHC proteins
MHC (major histocompatibility complex)
- do not respond to specific antigens
- SNITCHES
- take little fragment of antigen they ran into, and give it to T/B cell to fuck em up
APC- antigen presenting cells
both lymphocytes originate in red bone marrow
origin
lymphocytes can recognize only one specific antigen
immunocompetence
lymphocytes are educated and mature in primary lymphoid organs (thymus and red bone marrow)
maturation
lymphocytes must be unresponsive to own antigens
self- tolerance
t-cells mature in the thymus under neg. or pos. selection pressures
- positive; t cells capable of recognizing self- MHC proteins
- negative; apoptosis if bind to self-antigen displayed by self-MHC protein
maturation of T cells
in red bone marrow
- only immunocompetent B cells are allowed to mature
- those that are self reactive are eliminated by apoptosis
- clonal deletion
B cell maturation
immunocompetent B/T cells are called
naive
immunocompetent B/T cells are exported from primary lymphoid organs to “seed” secondary lymphoid organs
seeding secondary lymphoid organs and circulation
lymphocyte is selected to differentiate into active cell by binding to it’s specific antigen
- puts them front and center to battle with the antigen
clonal selection
lymphocyte that is now an effective/ active cell and forms exact copies of itself
clones
most clones become ________ _____ that fight infections
effector cells
a few remain as ____ cells
- able to respond to same antigen faster second time around
stay in seeding location (lymph nodes, spleen)
memory
engulf antigens and present fragments to T cells for recognition
dendritic, macros, B cells
- found in C.T and epidermis
- mobile sentinels of boundary tissue
- phagocytize pathogens that enter tissues, enter lymphs to present antigens to T cell in lymph node
- most effective antigen presenter known
- 1st and second line of defense
dendritic cells
- C.T and lymphoid tissue
-present antigen to t cells, activates macros and T cells
-macrophage activated- phagocytizer
trigger inflammatory response
macrophages
- do not activate naïve T cells
- present antigen to helper t cell to help their own activation
B lymphocytes
most clone cells become _____ ____, antibody secreting effector cells
- secrete 2000 antibodies per second for 4-5 days; then die
- antibodies circulate binding to free antigens, marking them for destruction
plasma cells
clone cells that done become plasma cells become ___ ___
- immunological memory
- immediate response to furture exposure to same antigen
memory cells
cell proliferation and differentiation upon exposure to antigen for lag time
- lag period; differentiation of b cell, antibodes are being secreted
- peak levels reached at 10 days
- then decline
- antibodies are tagging antigens for attack at 10 days
primary immune response
re-exposure to same antigen gives faster, more prolonged, more effective response
- sensitized memory cells provide immunological memory
- antibody peaks in 2-3 days
secondary immune response
active humoral immunity
formed in response to actual bacteria or viral infection
active humoral- naturally acquired
formed in response to vaccine of dead pathogens
- provide antigenic determinants that are immunodenic and reactive
- spare us symptoms of primary repsonse
artificially acquired- active humral
occurs when ready made antibodies are introduced into the body
- bcells aren’t challenged by antigens
passive humoral immunity
antibodies delivered to fetus via milk
naturally acquired- passive immunity
injection of serum, such as gamma globulin
artificially acquired- passive immunity
immunoglobulins (Igs) proteins secreted by plasma cells
- given in attempt to temporarily boost immunity
- derived from blood plasma (gamma globulin)
- can bind specifically w antigen detected by B cell
antibodies
____ is released during primary response, but plasma cell can switch to ____ for secondary response
IgM, IgG
almost all secondary responses are Ig_
IgG
antibodies don’t destroy antigens; they inactivate and tag them
- form _________
antigen-antibody (immune) complexes
defense mechanisms used by antibodies
neutralization
agglutination
precipitation
complement fixation
- simplest, but one of the most important defense mechanism
- antibodies block specific sites on viruses/ bacteria exotoxins
- prevent antigens from binding to receptor on tissue cell
neutralization
- antibodies can bind same determinant on 2 different antigens @ the same time
- each antibody has 2 arms
- allow for antigen-antibody complex to become crosslinked into clumps
aggultination
- soluble molecules are cross linked into complexes (not cells)
- complex precipitate out of solution
- precipitated complex easier for phagos to engulf
precipitation
- main body defense against cellular antigens
- several antibodies are bound close together on same antigen, complement binding sites on stem region align
- alignment- complement fixation- cell lysis-
complement fixation and activation
- 1st antibody secreted by plasma cells during primary response
- primary response antibody
IgM
- secretory antibody- found in body secretions
- saliva, intestinal juice
- try to stop initial contact w antigen
IgA
- found on surface of B cells
- antigenic determinant on B cell
IgD
- most abundant antibody
- all thru plasma content
- late primary and secondary response
IgG
- made in response to allergic reactions
- bind to mast cells, basophils
- full inflammatory response to pet danders
IgE
