module 4 Flashcards
purpose of immune system is to
identify self from non-self to protect
Innate immune system characteristics
(non-specific)
is the first line of defense
response time is immediate
cells are natural keller cells and simmilar
more widespread( found in other things)
Adaptive immunne system characteristics
(specific)
second line of defense
response time is long term
cells are T and B lymphocytes
3 steps of effective defense system
recognition
disposal
communication
Many microorganisms can be engulfed and digested by ____ un an unspecified way
phagocytes(macrophages)
macrophages are
- immediately available
- combat a wide range of microbes
- do not require prior exposure
- act the same way in all individuals
macrophages are phagocytes that
recognize engulf and digest foreign microbes
lipopolysaccharide(LPS) are found where
in bacterial cell wall
together Lipopolysaccharide(LPS) andDouble-stranded RNA collectivly make
PAMPs (pathogen-Associated Molecular Patterns)
adaptive immunity involves
the production of antibodies that are specific to a particular pathogen
two major categories of adaptive Immunity
humoral immunity and cellular immunity
humoral immunity coresponds to
B cell mediated response focusing on pathogens outside of cells also produce antibodies
cellular immunity coresponds to
T cell mediated response focusing on intracellular pathogens inside cells
an epitope
small molecular site within larger parasite molecule
an antigen
any part of a parasite that stimulates a specific immune response(contains 1 or more epitopes)
Immunoglobulins are
synthesized by a class of white blood cells called B lymphocytes that originate from stem cells in bone marrow
Antibodies
are complex proteins that cirulate extracellularly and bind to extracellular parasites
phagocytes vs lymphocytes
phagocytes are nonspecific lymphocytes are specific
regions of heavy chains
- Variable (V)
- diversity (D) genes
- joining (J) genes
regions of light chains
- V region
- J region
somatic recombination
brings together a V-D-J combination for the heavy chain (or V-J combination for the light chain
somatic hypermutation
mutations within individual lymphocytes only in B cells
Affinity Maturation
rapid clonal expansion of same antigen receptor increases mutation rate and variation(not in T cells)
negitive selection
clonal deletion/ removal of B ccells and T cells through apoptosis
positive selection
lymphocytes that encounter an antigen which their receptor binds
the inital infection is called
the primary response
MCH stands for
Major Histocompatibility complex
MHC class 1 molecules come from the
cytosol
MHC class 2 comes from
vesicles
antigenic variation
alterations in microbes proteins (antigens) in order to avoid a host immune response -> change in molecular structure of epitopes
benifits of antigenic variation
- extend length of infection and potentially increase R0
- Infect host with prior exposure that may be immune to a previous infection via immunological memory
escape mutants
pathogens with amino acid substitutions
Human leukocyte antigen(MCH in humans) is on what chromosome
chromosome 6
heterozygosity in MHC genes is
good and leads to larger variation of microbes targeted
durring antigenetic variation how is the length of infection extended
via rapid evolution and differential antigen expression
antigenic drift
regular evolution based on mutations arising in particular genes and natural selection acting on the most fit viruses
antigenic shifts
an entirely new gene enters the viruses that infect people
antigenic drift is caused by
point mutations in hemagglutinin and neuraminidase
