Adaptive Immune System

adaptive immunity

acquired ability to recognize and destroy a specific pathogen or its products

innate response

usually takes several days to initially develop

antigens

molecules that can be seen and identified by the immune system

tolerance

the acquired inability to make an adaptive immune response to ones own antigens discrimination between foreign and host antigens

failure to develop tolerance can lead to what

autoimmunity

immunocompetence

ability of the body to react with countless foreign substances

developing immune memory

first exposure to an antigen generates a primary immune response, involves a lag period of 4-14 days

subsequent exposure to the same antigen generates:

a faster and stronger secondary immune response

memory

lymphocytes have been programmed to recall their first engagement with the invader and rush to the attach once again

humoral immunity

primarily involved B cells and neutralizes threats outside human cells, extracellular fluids

cellular immunity

primarily involves T-cells and deals with threats inside cells

antibody/immunoglobulin

soluble protein made by a B lymphocyte or a plasma cell in response to antigen exposure

IgG

inflammation, cross the walls of blood vessels and enter tissue fluids, protect against circulating bacteria and viruses, enhance effectiveness of phagocytic cells

IgM

class of antibody involved in the response to the ABO blood group antigens on the surface of red blood

IgE

can provoke allergic reactions

IgA

localized protection of mucosal surfaces

IgD

presence on B cells functions in initiation of immune response

natural immunity

any immunity that is acquired through the normal biological experiences of an individual

artificial immunity

protection from infection obtained through medical procedures such as vaccines and immune serum

immunity acquired actively

when an individual receives immune stimulus that activates B and T cells to produce immune substances such as antibodies

creates memory

requires several days to develop, lasts for a long time

immunity acquired passively

when antibodies are transferred from another human or animal to another

lack of memory for the original antigen

lack of antibody production against the disease

naturally acquired active immunity

develops from exposure to antigens, illness, and recovery ex) immune response to an active microbial infection

naturally acquired passive immunity

transfer of antibodies to a fetus during pregnancy and via breast milk

newborn will be temporarily resistant to illnesses that mother is immune to

artificially active immunity

receiving a vaccination shot and developing immunity

artificially passive immunity

involves the injection of antibodies into the body. these come from an animal or a human who is already immune to the disease (covid-19)

variolation

smallpox prevention procedure involving inoculation of material from dried smallpox scabs into the respiratory tract or skin

vaccine

suspension of organisms or fractions of organisms that induce immunity

herd immunity

immunity in most of the population

effects of vaccination

provokes a primary immune response

leads to the formation of antibodies and long-lived memory cells

produces rapid intense secondary response

attenuated vaccines

weakened pathogen-reduced virulence

mimic an actual infection

lifelong immunity

not given to immunocompromised patients

inactivated vaccines

whole microbes are killed or inactivated

safer than attenuated vaccines

require repeated booster doses

induce mostly humoral immunity

subunit vaccines

use antigenic fragments to stimulate an immune response

recombinant vaccines

subunit vaccines produced by genetic modification of yeast or insects

toxoids

inactivated toxins

virus-like particle vaccines

resemble intact viruses but do not contain viral genertic material

polysaccharide vaccines

made from molecules in pathogens capsule, not very immunogenic

conjugated vaccines

polysaccharide antigen is attached to a protein

DNA vaccines

injected naked or encapsulated DNA into muscle

mRNA vaccines

mRNA enclosed in a lipid nanoparticle is injected into muscle where it directs the synthesis of the encoded antigen

recombinant vector vaccines

avirulent viruses or bacteria are generically modified to deliver DNA coding for antigens

is there a link between vaccines and autism

No

certain vaccine-preventable diseases persist

lower rate or vaccination due to poverty and lack of health infrastructure

some vaccine formulations need extra boosters to remain effective

avoidance of vaccination due to safety concerns

immunodeficiency

absence of a sufficient immune response

hypersensitivity

antigenic response that results in undesirable effects

autoimmune disease

immune system responds to self-antigens, causing damage to the organs

congenital immunodeficiencies

due to defective or missing genes, present from birth of shortly after

acquired immunodeficiencies

develop during an individuals life, due to drugs cancers or infections

hypersensitivity

antigenic response that results in undesirable effects

type 1: immediate/anaphylactic reactions

occurs minutes after a person sensitized to an antigen is re-exposed

combine with IgE

localized anaphylaxis

associated with limited body regions

immediate, temporary, less severe

ingested antigens, inhaled, contact (pollen, nuts, seafood, animal fur)

systemic anaphylaxis

involves cardiovascular and respiratory systems causing shock and breathing difficulties or death

injected antigens or bee stings may produce more dramatic responses

food allergies (peanuts, milk, soy, fish)

treated with epinephrine

type 2: cytotoxic reactions

activation of complement by the combination

of IgG or IgM antibodies with an antigenic cell

causes cell lysis or damage by macrophages

type 3: immune complex reactions

involved antibodies against soluble antigens circulating in the serum instead of antigens on cell/tissue surfaces

serum sickness, rheumatoid arthritis, lupus

type 4: delayed cell-mediated

cell-mediated immune responses caused by T cells

reaction takes a day or more to develop after antigen exposure

delayed hypersensitivity (poison ivy)

alpha-gal syndrome

allergic reaction to a sugar called alpha-gal

spread by lone star ticks

multiple sclerosis

autoantibodies, t cells, macrophages attack myelin sheath of nerves

symptoms range from fatigue to severe paralysis

compromises nerve impulse transduction

celiac disease

inflammatory autoimmune condition of the small intestine, triggered by gluten

damages the villi in the small intestine

systematic lupus erythematosus

patients make antiantibodies against cellular components such as DNA, most damaging against the kidney

rheumatoid arthritis

immune complexes of IgG, IgM and complement are deposited into the joints, chronic inflammation severely damages cartilage and bone in joints

graves disease

abnormal antibodies mimic thyroid stimulating hormone causing the thyroid to produce excessive amounts of thyroid hormones, pounding of the heart, trembling, sweating, bulging eyes

psoriasis

autoimmune disorders of the skin and joints

insulin-dependent diabetes

t cells destruction of insulin secreting cells of the pancreas