Micro - ch.15 - Adaptive Immune Response

what is the adaptive immune response?

slower

• specific to a pathogen

antigen

any molecule or molecule structure that can be specifically recognized by immune system  

• any pathogen or “self-antigens”

antibodies

“immunoglobulins”

• proteins bind to antigens to signal other immune cells to destroy it

What are the types of immunoglobulin?

IgG, IgD, IgE, IgA, IgM

IgG

most abundant antibody in blood

IgD

B cells

found in small amounts in blood 

IgE

allergic reactions

defense against parasite

histamine and basophils

IgA

found in mucus membrane secretion of tears and saliva

protects body surfaces that are exposed

“first line defense”

IgM

“flower shape”

first antibody produced to new infection

clumps 5 antigens at once

mast cells

release histamine when allergic reactions are triggered

histamine

dilates blood vessels to response of inflammation

speed up immune response

sometimes it overreacts to harmless substances 

• allergen - hypersensitive 

B cells

lymphocytes - type of WBCs

produces antibodies

recognize antigens → differentiate into plasma cells that secrete antibody and bind to antigens 

humoral immunity

type of adaptive immunity

involves production of antibodies by B cells

T cells

developed in thymus

recognize and respond to antigens 

what are the type of T cells?

helper T, cytotoxic T, regulatory T

Helper T cell

activities and turn immune system on

cytotoxic T cell

kill virus - infected cells, cancer cells or transplanted cells 

regulatory/suppressor cells

suppress overactive immune reactions or prevent autoimmunity

Cell mediated immunity

branch of adaptive immune response in which T cells recognized and respond to infection/abnormal/foreign cells by destroying them or activating other immune cells

lymphokines

signaling molecules (cytokines) secreted by lymphocytes especially T cells to attract other immune cells

primary immune response

initial response of immune system when it encounters antigen for first time

*7-10 days

specific

What is the first step to primary immune response?

microbe enters the body

What do macrophages do when the microbe enters the body?

they engulf (eat) the microbe (step 2)

What does the macrophage do after eating the microbe?

It displays pieces of the microbes (antigens) on its surface (step 3)

What type of T cells recognize antigens on macrophages?

helper T cells (step 4)

What happens when a helper T cell recognizes an antigen?

they become activated and divide to form “active T cells” (step 5)

What do active T cells do?

they stimulate other immune cells such as memory T cells  (step 5)

What are memory T cells?

they remain in the body for future encounters

What happens with active T cells?

they activate B cells that bound to the same antigen (step 6)

What happens when active T cells activate B cells?

The B cells divide into plasma cell and memory B cells (step 7)

What do plasma cells produce?

IgM antibodies first then IgG (step 8)

What do antibodies do?

bind the microbes to neutralize or mark them for destruction

What happens after antibodies bind to a microbe?

phagocytes destroy the pathogen (step 9-10)

What is the purpose of memory cells in the primary immune response?

they allow the immune system to respond faster and stronger during a second exposure to the same antigen

What happens in a secondary immune response?

it occurs when re-exposed to microbes but its faster and stronger because it “has the recipe” 

• relies on memory B and T cells 

What is Natural Active Immunity?

formation of antibodies and memory cells after exposure

What is Artificial Active immunity?

stimulated to produce a response by exposure through vaccines 

What is Natural Passive immunity?

receiving antibodies naturally through mother (placenta or breastmilk) - maternal 

What is Artificial Passive immunity?

made by another person or animal via injection (temporary)