ch 21 immune system part 2 Flashcards
lymphocytes
B cells and T cells which must mature before doing immune response
steps of lymphocyte activation
hematopoietic stem cell origination, education, seeding/circulation, antigen exposure, proliferation
education of stem cells in lymphocyte activation
immunocompetence- lymphocytes recognize single antigen to act against, one lymphocyte per one antigen
self tolerance- lymphocytes realize self vs non self
seeding and circulation in lymphocyte maturation
B and T cells colonize secondary lymphoid organs, and circulate through the body. ensures many T cells per pathogen
antigen exposure In lymphocyte maturation
first antigen encounter is clonal selection, which is one lymphocyte making more of itself with the same antigen specificity
proliferation in lymphocyte maturation
advanced lymphocyte proliferates to form lymphocytes with same receptor, same antigen specificity
form effector and memory cells. effector- carries out immune response while reaction occurs
memory- remembers already encountered pathogens and immune system reacts better
antigen presenting cells (APCs) why good
engulf antigen and display fragments from it. able to activate defenses earlier than if happened on its own
3 APC cells
dendritic- transport antigen back to lymphoid organ and display to local lymphocytes EARLIER ANTIGEN RESPONSE ALERT
macrophages- T cells activate macrophages that can transport antigens, present antigen to T cells and continue immune response DISPLAY OF ANTIGEN
B lymphocytes- present antigens to helper T cells for activation
B Lymphocytes and humoral immunity
involves production of plasma cells that produce and secrete antibodies for. a specific antigen
steps to produce plasma cells and antibodies
primary response- B cells are activated by binding of an antigen to multiple receptors on B cell surface e
clonal selection- clones recognize antigen shape
clone differentiation into dif cell types- can be plasma (reproduce and secrete antibodie) or memory B cells (remember antigens so immune response can launch and actually do response)
secondary response/immunological memory - on another slide
memory B cells in B lymphocytes and humoral Immunity do what
ensure memory of past antigen allowing immune response to occur, won’t occur unless its remembered
secondary response and immunological memory in B lymphocytes and humoral Immunity
after exposure, faster and more effective, higher antibody concentration un secondary response, retain ability to produce massive plasma numbers
active humoral immunity
B cells encounter antigens, produce plasma cells, and antibodies to act against them
can be naturally or artificially acquired
natural active humoral immunity
bacterial or viral infection occurs in body illness and infection will occur
artificial active humoral immunity
uses vaccines. dead antigens to launch immune response but without infection, then actual exposure will recruit memory B cells to do secondary immune response
passive humoral immunity
antibodies are supplied to the body, not produced- immune system not active. B cells are not interdicted to antigen, so memory cells not produced.
can be naturally or artificially acquired
natural passive humoral immunity
antibodies passed from mother to fetus or infant, it is then protected from antigens mom has already been exposed to. ends when birth occurs or breastfeeding ends
artificial passive humoral immunity
antibodies supplied by immune donor, protects from antigens that can kill a person before body can produce antibodies. ex- snakebites rabies or tetanus
antibodies types
immunoglobulins, IgM IgA IgD IgG IgE
IgM antibody
first class that is secreted by plasma cells during primary response, largest in spleen
IgA antibody
found in body secretions, sweat or saliva, prevents pathogens from attaching to epithelial surfaces, such as skin and mucous membranes
IgD
functions as B cell antigen receptor, so it activates B cell
IgG
most abundant antibody, main one of primary and secondary responses
IgE
releases histamine, mediates inflammation and allergy reaction
4 mechanisms of antibody actions
neutralization, agglutination, precipitation, complement activation
what is neutralization in antibody action
masks dangerous bacterial parts, by blocking the receptors on tissue cells, n phagocytes will destroy antibody antigen complex. IDs antigen for other immune cells to do their job.
agglutination in antibody actin
cell bound antigens, multiple binding sites for many antigens. get clumped together for easy phagocyte access.
precipitation in antibody action
soluble antigens, molecules clumped together and settle out of solution. makes it insoluble and engulf precipitate
complement activation in antibody action
multiple antibody binding close to same cell activates complement. effect- antigen lysis, increase inflammatory response, promotes phagocytosis
T lymphocytes and cellular immunity
direct attack on cancer cells, virus infected cells, and foreign transplant cells. T cells can’t see free antigens they need MHC bind
what is required to antigen presentation to T cells
MHC proteins.
antigen presenation
how the T cell activates, when the MHC protein binds the non self antigen, so MHC complex beginsn
antigen MHC complex
MHC protein displays non self antigen, T cell activated and immune response begins
T lymphocyte types
Helper T cells, cytotoxic T cells, regulatory T cells
helper T cells, TH
helps with humoral immunity, mediates immune responses. activates B cells and makes them divide a lot to form antibodies. TH cells stimulative destrictube T cells. activates innate system, macrophages go and WBC comes
cytotoxic T cells,TC
directly kill cells, mobile af, TC cells bind targets tight and release perforin which inserts pore to target membrane, and granzyme pumped into the pore to trigger apoptosis
main difference between NK and killer T cells
NK don’t need antigen presented, can notice by itself.
regulatory T cells (TREG)
dampen immune response to prevent spiraling, prevent a cytotoxic T cell from going crazy with its immune response. can be used for organ transplants to prevent rejection and autoimmune conditions to lessen severity. SLOWS IMMUNE SYSTEM
immunodeficiencies
any condition which impairs production or function of immune cells or molecules. congenital or maybe. not
SCID severe combined immunodeficiency syndrome
genetic defects that result in reduced lymphocyte production. congenital, virtually no protection from stuff anything minor can be fatal. hematopoietic stem cell can be used to improve survival
AIDS autoimmune deficiency syndrome
disease that interferes with TH cell activity. caused by HIV which s passed thru body fluids. HIV uses reverse transcriptase to replicate and spread virus, killing helper T cells. AIDs is pretty drug resistant, and no cure exists but antivirals can be used
autoimmune disorders
any disease where the immune system cannot recognize self from non self
autoimmunity
auto antibodies and TC cells destroy body tissues.
autoimmune examples of disorders
rheumatoid arthrirtis (joints), multiple sclerosis (CNS), graves (thyroid), type 1 diabetes (pancreas)
what issue arises w drugs that suppressbthe immune system
just a treatment, if all slows an individual is more likely to get an infection. lose lose
