Microbio Ch 15

Microbio Ch 15 - "adaptive, specific, immunity and immunization"

Specific Immunity

The Adaptive Line of Defense

Antigen

Molecules that stimulate a response by T and B cells

CD8 Cytotoxic T-lymphocyte

Required for antigen presentation and T cell activation

Migrate to the thymus to mature to become naïve T cells expressing CD4 or CD8 receptors

T cells

Function of their receptors is in surveillance and recognition

Lymphocyte Receptors

Bind processed antigens together with the MHC molecules on the cells that present antigens to them

T-cell receptors

Found on T-helper cells and help with binding

CD4 receptor

Found on Cytotoxic T-cells

CD8 receptors

Cytotoxic T cell that kills infected cells.

CD8 T cell

Molecule presenting antigens to CD8 T cells.

MHC class I

B cells that secrete antibodies.

Plasma cells

Initial antibody production after first antigen exposure.

Primary response

Faster, stronger response upon re-exposure to antigen.

Secondary response

Rapid antibody production on subsequent antigen encounters.

Anamnestic response

Specific site on an antigen recognized by antibodies.

Epitope

Small molecules that become antigenic when bound.

Haptens

Type of immunoglobulin used for passive immunity.

Gamma Globulin

Duration of Passive Immunity

2-3 months

Insert microbial DNA into host cells for immunity.

DNA Vaccines

Injects mRNA to produce antigens in cells.

mRNA Vaccines

Specific parts of antigens recognized by immune system.

Antigenic Determinants

Toxins used in vaccines like diphtheria and tetanus.

Exotoxins

“antibodies produced function only against the antigen they were produced in response to”

specificity

“lymphocytes are programmed to “recall” their first encounter with an antigen and respond rapidly to subsequent encounters”

memory

Major Histocompatibility complex (MHC) class I receptors are found on =

all cells except RBCs

Major Histocompatibility complex (MHC) class II receptors are found on =

immune cells only

another term for Major Histocompatibility complex (MHC) =

human leukocyte antigen (HLA)

protein that presents endogenous self antigens and intracellular foreign antigens, regulates immune reactions, required for CD8 cytotoxic T-lymphocyte antigen presentation and CD8 T cell activation =

MHC class I

regulatory receptors found on macrophages, dendritic cells, and B cells =

MHC class II

lymphocyte stem cells differentiate into pre-T cells or pre-B cells in the ____

bone marrow

B cells stay in the _____ to mature to become naive B cells

bone marrow

T cells migrate to the _____ to become naive T cells expressing CD4 or CD8 receptors

thymus

both B and T cells migrate to secondary lymphoid tissues to encounter antigens and become 1. _____, 2. _____

activated T cells, plasma B cells

B cell receptors function to

bind free antigens

T cell receptors function to

bind processed antigens together with MHC molecules

large glycoproteins that serve as specific receptors of B cells

immunoglobulins

when a B cell receptor (immunoglobulin) is secreted, it is called =

antibody

T cell receptors for antigens are arranged in =

two parallel polypeptide chains

T cell receptor most commonly come as =

alpha chain and beta chain

1-5% T cell receptors come as =

gamma chain and beta chain

CD4 T cell receptors are found on =

helper T cells

CD8 T cell receptors are found on =

cytotoxic T cell/lymphocyte

mature T cells migrate to lymphoid tissues to be activated by

antigen presentation

memory CD4 T cell functions to

remember pathogens, activate cells if they return

helper CD4 T cell functions to

help activate other cells by secreting cytokines

regulatory CD4 T cell functions to

regulate immune response

T helper 17 T cell functions to

recruit neutrophils and kill helminths

memory B cell functions to

remember pathogens and make antibodies if they return

Plasma B cell functions to

make antibodies now

memory CD8 T cell functions to

remember pathogens and kill infected cells if they return

cytotoxic CD8 T cell/Killer T cells function to

lyse infected cells

punch holes in target cells and are good at identifying cancer cells

perforins

eliminate infected or cancerous cells by inducing programmed cell death (apoptosis)

granzymes

programmed cell death

apoptosis

antibodies fill the surface receptors on a virus or the active site on a microbial enzyme to prevent it from attaching

neutralization

process of coating microorganisms with specific antibodies so they are more readily recognized by phagocytes

opsonization

increases the rate of phagocytosis

antibody tagging

activation of the classical complement pathway can result in the specific rupturing of cells and some viruses

complement fixation

the 5 glasses of immunoglobulins

igg, iga, igm, igd, ige

immunoglobulin produced upon first encounter with an antigen, can serve as B cell receptor

igm

most prevalent immunoglobulin, produced by plasma cells in primary response and memory cells in secondary response

igg

immunoglobulin that circulates in blood, dimer in mucous and serous secretions, found in GI and respiratory tract, passed to newborns in breast milk

iga

immunoglobulin that serves as B-cell receptor for antigens on B cells

igd

immunoglobulin involved in allergic responses and parasitic worm infections

ige

the third line of defense

antibody-mediated immunity by B cells

after first exposure to an antigen, immune system produces IgM and gradual increase in antibody titer with production of IgG

primary response

after second contact with same antigen, immune system produces a more rapid, stronger response due to memory cells

secondary response

renewed rapid production of an antibody on the second or subsequent encounter with the same antigen

anamnestic response

all antibodies in the IgA class =

have identical Fc regions

property of behaving like an antigen

antigenicity

antigenic determinant, small molecular group that is recognized by lymphocytes/antibodies

epitope

antigenic determinant, small simple molecules, or large with several repeating units. this is recognized by lymphocytes/antibodies

immunogens

small foreign molecules that consist only of a determinant group, not antigenic unless attached to a larger carrier

haptens

potent T cell stimulators; provoke an overwhelming response

superantigens

antigen that evokes allergic reactions, IgE

allergen

molecules on self tissues for which tolerance is inadequate

autoantigens

results when a person is challenged with an antigen that stimulates production of antibodies, created memory, takes time and is lasting

active immunity

preformed antibodies are donated to an individual, does not create memory, acts immediately, and is short lived

passive immunity

immunity required as part of normal life experiences

natural immunity

immunity acquired through a medical procedure such as a vaccine

artificial immunity

diphtheria, botulism, and snake bites are treated with

sera derived from horses

immune serum globulin (ISG), gamma globulin, contains immunoglobulins extracted from pooled blood

immunotherapy

deliberately exposing someone to material that is antigenic but not pathogenic

artificial active immunity

cultivate the desired strain, treat it with an agent that kills the microorganism but does not destroy its antigenicity, often require a larger dose and more boosters

killed/inactivated vaccine

process that substantially lessens or negates the virulence of a virus or bacteria, eliminates virulence factors, long lasting protection, fewer doses and boosters. cons: require special storage and can mutate back to virulent strain

live attenuated vaccine

isolated antigen molecules used for vaccine, no intact pathogen present, can be taken from cultures or synthesized

acellular/subcellular vaccine (subunit if a virus)

genetic material from a pathogen is inserted into a live carrier nonpathogen, the recombinant expresses the foreign genes causing an immune response

Trojan horse/genetically engineered vaccine

a substance that enhances immunogenicity and prolongs retention of an antigen

adjuvant

concept that immune individuals will not harbor a pathogen, thus reducing the occurrence of pathogens

herd immunity

molecules that stimulate a response by t and B cells

antigen