CHAPTER 27 Flashcards
ADAPTIVE IMMUNITY: HIGHLY SPECIFIC HOST DEFENSES
a molecule capable of interacting which specific components of the immune system and that often functions as an immunogen to elicit an adaptive immune response
ANTIGEN
a cell surface immunoglobin that acts as an antigen receptor a B cell
B CELL RECEPTOR (BCR)
a protein found on Th cells that interacts with MHCII on an antigen-presenting cell
CD4 CORECEPTOR
a protein found exclusively on Tc cells that interacts with MHCI on a target cell
CD8 CORECEPTOR
the inability to produce an immune response to specific antigens due to the neutralization of effector cells
CLONAL ANERGY
for T cell selection in the thymus or B cell selection in the bone marrow, the elimination by apoptosis of useless or self-reactive precursor lymphocytes
CLONAL DELETION
following its activation, the proliferation and differentiation of a naive T or B lymphocytes into a clone of effector cells
CLONAL EXPANSION
lymphocytes of identical antigen specificity that have arisen from a single, activated progenitor cell
CLONE
a varying amino acid sequence within the variable domains of immunoglobulins or T cell receptors where contacts with antigen are made up
COMPLEMENTARY-DETERMINING REGION (CDR)
the portion of an antigen that reacts with a specific antibody or T cell receptor
EPITOPE
an antigen-presenting protein encoded by a major histocompatibility complex gene in humans
HUMAN LEUKOCYTE ANTIGEN (HLA)
the ability to rapidly produce large quantities of specific immune cells or antibodies after subsequent exposure to a previously encountered antigen
IMMUNE MEMORY (MEMORY)
a molecule capable of eliciting an adaptive immune response
IMMUNOGEN
a family of genes that are evolutionarily structurally, and functionally related to immunoglobulins
IMMUNOGLOBULIN GENE SUPERFAMILY
a long-lived B or T lymphocyte responsive to a specific antigen
MEMORY CELL
an antigen-presenting molecule found on all nucleated vertebrate
MHC CLASS I PROTEIN
an antigen-presenting molecule found on macrophages, b cells, and dendritic cells
MHC CLASS II PROTEIN
in antigen presentation, a specific amino acid seqeunce found in all peptides that to a given MHC protein
MOTIF
in T cell selection, the deletion of T cells that interact strongly with self antigens in the thymus
NEGATIVE SELECTION
the occurrence of two or more genetically, structurally, and functionally related gene loci due to an evolutionary gene duplication event
POLYGENY
in a population, the occurrence of multiple alleles for a gene locus at higher frequency that can be explained by recent random mutations
POLYMORPHISM
in T cell selection, the growth and development of T cells that interact with self MHC-peptide in the thymus
POSITIVE SELECTION
the production of antibodies or immune T cells on first exposure to antigen; the antibodies are mostly of the IgM class
PRIMARY IMMUNE RESPONSE
the enhanced production of antibodies or immune t]T cells on second and subsequent exposures to antigen; the antibodies are mostly of the IgG class
SECONDARY IMMUNE RESPONSE
the mutation of immunoglobulin genes at rates higher than those observed in other genes
SOMATIC HYPERMUTATION
the ability of cells of the adaptive immune response to interact with particular antigens
SPECIFICITY
an antigen-specific receptor protein on the surface of T cells
T CELL RECEPTOR (TCR)
a lymphocyte that interacts with MHC-I peptide complexes through its T cell receptor and produces cytotoxins that kill the interacting target cell
T-CYTOTOXIC (Tc) CELL
a lymphocyte that interacts with MCH II-peptide complexes through its T cell receptor and produces cytokines that act on other cells. Th subsets include Th1 cells, which activate macrophages, Th2 cells, which activate neutrophils; and Th17 cells, which suppress adaptive immunity
T-HELPER (Th) CELL
the acquired inability to produce an immune response to particular antigens
TOLERANCE
the inoculation of a host with inactive or weakened pathogens or pathogen products to stimulate protective active immunity
VACCINATION (IMMUNIZATION)
major circulating antibody; four sub-classes: IgG1, IgG2, IgG3, IgG4; IgG1 and IgG3 activate complement
IgG
first antibody to appear in primary response to extracellular pathogens or after immunization; pentamer especially effective in agglutinating antigens; strong complement activator
IgM
important circulating and major secretory antibody
IgA
minor circulating antibody; mostly associated with mature B cells
IgD
facilitates parasite immunity but also triggers allergic reactions
IgE
True or False. Bloodborne pathogens/antigens are captured in the spleen, where IgM, IgG and serum IgA antibodies are produced.
TRUE
the MHC proteins in humans were first identified as the major antigens responsible for immune-mediated tissue transplant rejection
HUMAN LEUKOCYTE ANTIGEN (HLAs)
True or False. Tc cells express the CD8 coreceptor, and Th cells express the CD4 coreceptor
TRUE
True or False. MHC proteins in different individuals of the same species are not identical. Different individuals typically have subtle differences in the amino acids sequence of homologous MHC proteins.
TRUE
produce IL-2, a cytokine that promotes growth and activation of other cells, and also activate macrophages through the cytokines interferon gamma, tumor necrosis factor alpha, and granulocyte-monocyte colony-stimulating factor
Th 1 cells
play a pivotal role in B cell activation and antibody production
Th 2 cells
its function to produce IL-17, starting a cascade that draws neutrophils to infection sites
Th 17 cells
shut down the immune response and inhibit inflammation
Treg cells
