Med Micro - quiz 5 study guide

what is the third line of immune defense?

adaptive immunity

what two responses are included in adaptive immunity?

cellular response and humoral response

what is specificity?

recognizes antigens of an invader

what type of antigens are recognized through specificity?

specific LPS and flagellin of E. coli O157:H7

what is O157?

antigen on the LPS of only that E. coli strain

what is H7?

antigen on the flagellin protein of only that E. coli strain

what does the adaptive immune response have the ability to recognize?

self vs non-self

the adaptive immune response is only made to what?

to foreign substances (does not harm self tissues)

the adaptive immune response minimizes what type of damage?

self damage

the adaptive immune response must be strong enough to eliminate the pathogen, but not cause what?

extensive damage to the tissues and organs of the body

what is immunological memory?

an amount of rapid and vigorious response to previously encountered pathogen

with immunological memory, the subsequent exposure to the same pathogen produces such a rapid/vigorious response that what happens?

the person is not even aware they were exposed?

what is immunological memory the basis for?

vaccination

what is humoral immunity?

antibody-mediated immunity

with humoral immunity, what are antibodies produced by?

plasma B cells

with humoral immunity, what do antibodies do?

they bind to specific foreign substances outside host cells

antibodies do what to microbes?

only bind to them (do not kill them)

where do antibodies circulate at?

in the blood (fluid, or humoral)

what is cell-mediated immunity?

for infected cells and other non-self cells

with cell-mediated immunity, T cells directly interact with what?

cells infected with a specific pathogen (cell mediated) or other non-self cells

what type of cells are used with cell-mediated immunity?

T helper and T cytotoxic cells

antigens are immunogenic, meaning what?

they trigger an immune response

what is immunogenicity impacted by?

size, complexity, and composition

what is most immunogenic to least?

proteins, polysaccharides, and then lipids

what is an antigen?

an antibody generator

what is a bacterial antigen?

specific sites on capsules, cell walls, flagella, fimbriae, toxins, and others

what are other types of antigens?

pollen, egg whites, RBC’s, tissues from transplants, serum proteins, viral coats, and others

where is the H7 antigen located on with E. coli?

flagellum

where is the O:157 antigen located at with E. coli?

cell wall (LPS side chains)

why do most bacterial species elicit an adaptive immune response?

because they have multiple antigens

the adaptive response of most bacterial species results in what?

the production of multiple different antibodies against the pathogen

what are antibodies also known as?

immunoglobulins

what are antibodies?

proteins made in response to an antigen by B cells (when the antigen is encountered outside host cells)

antibodies recognize and bind to what?

one specific antigen

antibodies are highly specific, meaning what?

they only recognize the antigen that stimulated their original formation

what does it mean when an antibody is bivalent?

it has two antigen-binding sites

with bivalent antobodies, all binding sites on the same antibody bind what?

the same antigen

with bivalent antibodies, some have what?

multiple subunits

B cells have antibodies on their surface which do what?

bind to antigens

what do antibodies do to antigens/pathogens?

they only bind to them and form antigen-antibody complexes (they do not kill or destroy them!)

what are the subunits of an antibody?

2 identical antigen-binding sites (Abs) and one Fc region

what does the Fc/stem region of an antibody bind to?

the surface of B cells and Fc receptors on phagocytes

B cell surface-bound antibodies occur as what?

monomers

why is each monomer referred to as bivalent?

because they each have 2 identical antigen-binding sites

what are examples of monomers?

IgD, IgE, and IgG

what is both monomers and dimers (1 and 2 subunits)?

IgA

what is made up of 5 monomers joined (a pentamer)

IgM

what is found as a monomer on B cells?

IgM

what is the structure if IgG?

monomer

what is the proportion of antibody pool with IgG?

most abundant

what is the neutralization of IgG?

strong

what is the complement activation with IgG?

strong

what is the opsonization with IgG?

strong

what are some notes over IgG?

crosses placenta; made later in infection

what is the neutralization of IgA?

strong

what are some notes of IgA?

main antibody in milk; resistant to destruction by stomach acid

what is the agglutination/precipitation of IgM?

strong

what are some notes of IgM?

made early in infection; large structure limits where it migrates

what type of antibody makes up 80% of serum antibodies (most abundant)?

IgG antibodies

what do IgG antibodies cross?

the walls of blood vessels to enter tissues

what do maternal IgG antibodies cross?

the placenta to help protect the newborn

what does IgG antibodies deal with?

opsonization, activates complement, neutralizes toxins

with IgG antibodies, their levels increase mostly after what?

the second exposure to antigens

IgG antibody presence indicates what?

the late stage of an initial antigen exposure, or a prior exposure to the antigen (infection or vaccination)

IgA antibodies are a monomer in what?

blood

IgA antibodies are dimers in what?

body secretion (sIgA)

why is the IgA antibody an important part of mucosal immunity?

it provides protection at all mucus membranes (MALT)

IgA antibodies prevent what?

attachment of antigens and neutralizes toxins

where are IgA antibodies found?

in tears, saliva, and breast milk (infant protection)

with IgA antibodies, the secretory component protects against what?

enzymatic degradation

what type of detection is MALT?

pathogen detection

what does MALT stand for?

mucosa-associated lymphoid tissue

what is the MALT?

a diffuse system of lymphoid tissue

secretory IgA helps provide what?

protection

MALT is found where?

in all mucosal linings (respiratory tract, GI tract, Peyer’s patches of ileum, GU tract..)

what are examples of MALT?

tonsils, appendix, and Peyer’s patches

MALT is often more specifically named based on what?

its location in the gut

what is GALT?

gut-associated lymphoid tissue

secretory IgA is secreted into what?

into the lumen to attach to pathogens, antigens

cells of the MALT sample the environment of the lumen by what?

phagocytosis

with the MALT, after phagocytosis, antigens/pathogens are then what?

presented to lymphocytes in the MALT

the MALT may become enlarged and inflamed due to what?

an infection

what is an example of neck region inflammation?

tonsillitis

what is an example of an enlargement/inflammation due to MALT infection?

buboes of plague

where are IgM antibodies found?

in blood and lymph

IgM antibodies are on what cells?

B cells (as a monomer)

IgM antibodies do what?

agglutinate microbes, activate complement, and neutralize toxins

what is the first antibody produced in response to infection?

IgM antibodies

the presence of IgM antibodies indicates what?

recent exposure to an antigen

IgM antibodies are normally what shape?

pentamer

IgD and IgE antibodies are both what?

monomers

what antibodies are found in very small amounts in the body?

IgD and IgE antibodies

what antibody serves as a B cell receptor?

IgD antibody

what antibody is bound to receptors on mast cells, eosinophils, and basophils?

IgE antibody

what do IgE antibodies cause?

the cells to release histamine (allergies)

IgE antibodies help control what?

infections by worms

what is the half-life of both IgD and IgE antibodies?

2 days

how do antibodies neutralize antigens?

antibodies block toxins or antigens from binding to host cells

how do antibodies activate complement?

cytolysis, opsonization, inflammation

how do antibodies increase phagocytosis?

as antibodies precipitate, agglutinate, or opsonize antigens