Chapter 16 (Specific Defenses) Flashcards
Describe the properties and classes of antigens.
o Define “antigenic determinant” (or “epitope”)
a 3-D shapes antigen that the immune system recognizes
Describe the structure and functions of antibodies.
o Name and describe the six potential results that can occur when an antibody binds to an antigen.
NEUTRALIZATION: cover pathogen/toxin so that it cannot bind
OPSONIZATION: phagocytes bind Fc region (receptor protein) of antibody
OXIDATION: enzyme function makes reactive oxygen that kills bacteria
AGGULATION: binding pathogen together to prevent spread & escape from immune cells
ANTIBODY-DEPENDENT CELLULAR CYTOTOXICITY
What is the major histocompatibility complex?
o What cells have MHC-I?
o What cells have MHC-II?
o What are these used for?
Allow body cells to alert the immune system that there is an invader present
MHC-I: all nucleated cells
displays ENDOGENOUS antigens to cytotoxic T cells
Message: INTRACELLULAR (virus, bacteria, tumor cell) pathogen present
Result: Activation to Cell-Mediates Immune Response
MHC-II: Antigen Presenting Cells (APCs) [B cells, phagocytic cells {dendritic cells, macrophages}]
displays EXOGENOUS antigens to helper T cells
Message: EXTRACELLUAR pathogen of TOXIN present
Result: activation of Humoral Immune Response
What are the different types of lymphocytes?
o Distinguish between the functions of inactive B lymphocytes and plasma cells.
B lymphocytes mature in BONE MARROW found in LYMPH NODES
each active B cell secretes an antibody that can stick to a particular antigenic determinant/ epitope. Active B cells are called plasma cells. Antibodies circulate through lymph & blood
What are the different types of lymphocytes?
o Distinguish between the functions of the three types of T lymphocytes.
Mature in the THYMUS
CYTOTOXIC T CELLS
secretes cytokines to induce itself to reproduce= self stimulation
kill “bad” cells-abnormal cells (cancer) -infected cells (virus, bacterium)
HELPER T CELLS( TH1 & TH2)
used to activate Tcyt cells & B cells
secrete protein messengers called CYTOKINES (interleukins [IL] & Interferons)
TH1:assist Tcyt cells
TH2: assist B cells → in becoming plasma cells
What are the different types of lymphocytes?
o What are memory cells? How are they used?
What are the different types of lymphocytes?
o What is clonal deletion?
all B cells receptors get checked for binding of autoantigens (body cells) any that bind are destroyed
Describe the Humoral Response
o What is the main lymphocyte involved? (B cell or cytotoxic T cell?)
o What type of Helper T cell is required?
o Which MHC is/are involved?
o What types of antigens does it respond to?
o What is the result of the immune response? (i.e.: do the activated cells make something or do something?)
o Describe the overall process used to activate the response.
o What is clonal selection?
B cells: plasma cells & memory cells
T cells: TH2 - converting naïve B cells to plasma
MHC-II
Exogenous antigens
PROCESS:
1. antigen presentation-APC takes invader by phagocytosis
2. TH→ TH2 -TH clones itself APC secretes a cytokine (interleukin) to activate the helper T cell. TH to changes to a TH2
3. Clonal selection- selecting for the B cell “clone” that can recognize the antigen
4. B cell Activation Memory
5. Immunological Memory
TH2 secretes a cytokine (another interleukin) B cell activates
1. lots of PLASMA CELLS are made → secrete antibody
2. some MEMORY CELLS made
Name and describe the 4 different methods in which humans gain immunity.
ACTIVE/NATURALLY AQUIRED: Immune response to antigens that enter body naturally
ACTIVE/ ARTIFICALLY AQUIRED: Immune response to antigens that enter body via vaccine
PASSIVE/ NATURALLY AQUIRED: Antibodies passed from mom to child (placenta & breast milk)
PASSIVE/ ARTIFICALLY AQUIRED: Antibodies received as antisera or antitoxin (gamma globulin for Hep A)
Compare/contrast active and passive immunity.
ACTIVE immune system generates response to make memory
PASSIVE: receive antibodies
the end
Define Specific Immunity
the body’s ability to detect & react to distinct invaders AKA adaptive immunity/response
Describe the Cell-Mediated Response.
o What is the main lymphocyte involved? (B cell or cytotoxic T cell?)
o What type of Helper T cell is required?
o Which MHC is/are involved?
o What types of antigens does it respond to?
o What is the result of the immune response? (i.e.: do the activated cells make something or do something?)
o Describe the overall process used to activate the response.
o What is clonal selection?
No B cells used
T cells: TH ; Tcyt
MHC-1 & MHC-II
ENDOGENOUS ANTIGENS
PROCESS:
Antigen presentation ( TH →TH1)
Clonal Selection
Tcyt cell activation & memory cells
RESULT: T cyt releases chemicals that cause infected cell to undergo APOPTISIS (self destruct) CHEMICALS:
PERFORIN- create pore in infected or abnormal cell
GRANZYME- enters cells through pore & activates self-destruct proteins
DEFINE ENDOGENOUS
found in invader that are inside of body cells
the immune system cannot “see” these directly
DEFINE AUTOANTIGENS
found on body cells
precents your immune system from attacking YOUR HEALTHY cells
