Chapter 4: Altered Immunity Flashcards
immunity
the process by which the body recognizes foreign substances and neutralizes them to prevent damage
specificity
the immune cells seek out and destroy targeted foreign invaders
memory
the immune cells produce substances that remember and more easily destroy return offenders
immunology
the study of the structure and function of the immune system, immunity, induced sensitivity, and allergy
adaptive immunity
immune response that is stimulated when specialized cells come in contact with an antigen
antigen
a substance that induces a state of sensitivity or immune response
lymphoid progenitor
precursor cell to natural killer cells, T lymphocytes, and B lymphocytes
myeloid progenitor
precursor to monocytes, dendritic cells, granulocytes, and mast cells
T lymphocytes
mature and fully differentiate in the thymus; require contact with antigen to proliferate and differentiate into cytotoxic, helper, or suppressor T cells
suppressor T lymphocytes
limit/inhibit humoral and cell-mediated immune responses
T cell receptor (TCR)
receptor unique to an antigen that is able to bind to that specific antigen and promote and specific immune response
B lymphocytes
develop in the bone marrow and migrate to peripherla lymphoid tissues when they are activated by an antigen to differentiate to plasma cells or become memory cells
B-cell receptor (BCR)
antigen-specific receptor on the plasma membrane of B cells
immunoglobulin (Ig)
globular proteins which are secreted antibodies that detect antigens
natural killer (NK) cells
large, granular lymphocytes that are active in innate immunity and kill infected or tumor cells
granulocytes
polymorphonuclear, phagocytic WBCs with granules
neutrophils
most common granulocyte that rapidly responds to bacterial infection and responds first in inflammatory response
eosinophils
protect against parasites
basophils
compliment mast cells and are important for allergic reactions
monocytes
large, mononuclear leukocytes that are immature until activated by an antigen
macrophage
mature monocyte that digest antigen-carrying cells and antigens
dendritic cells
mature dendritic cells take antigens to lymph nodes for B and T cell activation
langerhans cells
immature dendritic cells in the skin
lymph
liquid filtration product of extracellular fluid from tissues that is returned to blood
lymph nodes
joined segments of lymphatic vessels
naive lymphocytes
lymphocytes that have not yet encountered the antigen
apoptosis
programmed cell death
innate immunity
first responder to injury that is rapid and nonspecific
antigen-presenting cells (APCs)
cells that present digested antigens on the outside
humoral immunity
adaptive immunity that involves antibodies
antibodies
immunoglobulins that react with an antigen in a specific way
effector cells
plasma cells that secrete antibodies
memory cells
activated, mature B cells that remain after the antigen is eliminated
immunologic memory
ability of the immune system to recognize antigens
clonal selection
clones of B cells carrying specific BCRs for specific antigens
clonal expansion
B cell clones differentiate into plasma cells
neutralization
binding of antigen to the antibody so that the antigen cannot infect cells
opsonization
promoting phagocytosis and destruction of the pathogen through the phagocyte’s ability to recognize that constant region of the antibody
cell-mediated immunity
a component of the adaptive immune response that results in the recognition and destruction of cells with non-self antigens
epitope
the part of the antigen to which an antibody attaches
clusters of differentiation (CDs)
membrane surface molecules that determine functions and responses of T cells
cytotoxic T lymphocytes (CD8 T cells)
T cells that destroy infected or tumor cells
helper T lymphocytes (CD4 T cells)
T cells that enhance the cell-mediated response
TH1 cells
T helper cells that activate macrophages, secrete chemokines and cytokines to attract macrophages, promote fusion of lysosomes with vesicles containing bacteria, and stimulate phagocytosis
TH2 cells
T helper cells that activate B cells to produce antibodies
human leukocyte antigens (HLAs)
MHC molecules that display antigens
MHC class I molecule
found on nucleated body cells and is recognized by cytotoxic CD8 lymphocytes
MHC class II molecule
found on APCs and is recognized by helper CD4 T lymphocytes
host
person on which the pathogen lives
antigenic variation
when pathogens have multiple variations of antigens that trick T and B lymphocytes and make recognition difficult
latency
a period of inactivity for viruses where it is not being replicated and remains undetected
immunodeficiency
immunosuppression due to impaired immune responsiveness
hypersensitivity
excessive immune responses to allergens
allergens
antigens commonly considered to be harmless
immediate hypersensitivity reactions/type I reactions
immediate IgE-mediated reactions to soluble antigens that induce allergic response of inflammation or anaphylaxis
atopic
IgE responses are stimulated from exposure to typically benign substances
anaphylaxis
edema and vasodilation that leads to hypotension
type II antibody-mediated reactions
IgG or IgM mediated, tissue-specific response to normal antigens on cells or drugs
type III immune complex-mediated reactions
IgG and IgM mediated cellular and tissue damage caused by complement activation stimulated by antigen-antibody complexes that clog vessels and tissue
serum sickness
local signs and symptoms of rash and itching with systemic edema and fever due to antigen-antibody complexes clogging blood vessels and tissue
Arthus reaction
complex-mediated immune response results in localized tissue necrosis in the skin
type IV cell-mediated hypersensitivity reactions
T cell-mediated reactions that cause in inflammatory response that results in cell lysis
direct cell-mediated toxicity
damage to cells and tissues as a direct response to CD8 cytotoxic T cell destruction of cells with recognized antigens, which can be more harmful than the pathogen
delayed hypersensitivity reactions
CD4 helper T cells respond to antigens to stimulate response against unharmful molecules
sensitization phase
phase of delayed hypersensitivty that begins when the antigen crosses the skin and are presented to T helper cells to activate them and produce memory cells
elicitation phase
memory T cells in the dermis are stimulated by subsequent exposure to the antigen and cytokines and chemokines are released to attract macrophages and T cells, which produces local swelling and contact dermatitis
autoimmunity
immune response directed at one’s own tissues
lymphocyte ignorance
converting lymphocytes from nonresponsive to self-reactive
molecular mimicry
close resemblance between foreign and self-antigen
familial tendency
propagation of autoimmunity among family members
regulatory T cells
suppressor T cells that are able to suppress autoreactive lymphocytes and regulate the immune response
alloimmunity
when an immune response is stimulated in response to the presence of cells from another individual of the same species
grafts
unattached tissues or organs used for implantations
polymorphic
occurring in more than one form
polygenic
containing several MHC class I and II genes
autograft
grafts from different sites on the same person
syngenic
grafts from genetically identical individuals/monozygotic twins
allograft
graft between unrelated individuals
alloantigens
proteins that vary between individuals
alloantibodies
antibodies produced against alloantigens
hyperacute graft rejection
rapid rejection of grafts due to alloantibodies
graft versus host disease (GVHD)
when the T cells of the donor recognize the recipient’s body as being different or foreign and mount and attack
hematopoietic stem cells
cells that can differentiate into healthy blood cells
vaccines
stimulating immunity through exposure to antigen
attenuated
reduced ability to cause disease
conjugated vaccines
vaccines that promote activations of more than one cell type
acquired immunodeficiency syndrome (AIDS)
the loss of cell-mediated and humoral immunity due to the loss of CD4 Th1 lymphocytes caused by HIV
human immunodeficiency virus (HIV)
enveloped retrovirus that infects CD4 helper cells, dendritic cells, and macrophages and results in a loss of CD4 T cells
seroconversion
asymptomatic period when one develops antibodies to HIV
urticaria
itching
angioedema
sudden subcutaneous swelling
systemic lupus erythematosus (SLE)
autoimmune disease that is a result of persistent antibody-antigen complex deposition and inflammation
quiescence
decreased symptoms
Rh isoimmunization
direct antigen-antibody hypersensitivity reaction between a mother and her fetus that results in cell destruction of the fetal red blood cells
hemolytic disease of the newborn (HDN)
cell destruction of the fetal red blood cells that causes hemolytic anemia in the fetus or newborn
hydrops fetalis
swollen fetal tissues
kernicterus
brain damage caused by unconjugated bilirubin deposits in the basal ganglia and brainstem nuclei
