Immune System

Immune SystemImmune System

Immune SystemImmune System

► A collection of A collection of mechanisms within mechanisms within an organism that an organism that protects against protects against disease by disease by identifying and identifying and destroying destroying pathogens and pathogens and tumor cellstumor cells

PathogensPathogens

► Anything in an Anything in an organism that is not organism that is not “self”“self”

► Body can recognize Body can recognize “self” and identify “self” and identify pathogens based on pathogens based on cell receptorscell receptors

What happens when something What happens when something gets into the body?gets into the body?

► They would have They would have needed to first pass needed to first pass through our surface through our surface barrierbarrier

► This can happen.This can happen.►Our next level of Our next level of

immune system immune system now goes to worknow goes to work

Innate Immune systemInnate Immune system

►Workhorse of the Workhorse of the immune systemimmune system

►Nonspecific, will try Nonspecific, will try to defend against to defend against any intruder. any intruder.

► Include Include InflammationInflammation Complement systemComplement system Cellular barriersCellular barriers

InflammationInflammation

Complement SystemComplement System

►System of Proteins that help the body System of Proteins that help the body recognize and quickly rid itself of recognize and quickly rid itself of pathogenspathogens

► Includes 20 or proteinsIncludes 20 or proteins►Some are proteases and assist in Some are proteases and assist in

killing pathogenskilling pathogens

Cellular barriersCellular barriers

►White blood cellsWhite blood cells►Many different Many different

typestypes► Each type has a Each type has a

different role, or different role, or areaarea

► Engulf pathogens Engulf pathogens and break them and break them downdown

Adaptive ImmunityAdaptive Immunity

►Our bodies can Our bodies can remember remember pathogens, and pathogens, and make specific make specific defenses against defenses against themthem

► This is called an This is called an immunityimmunity

► Recognizes specific Recognizes specific antigensantigens

How does this work?How does this work?

► Antigen Antigen PresentationPresentation Phagocyte engulfs Phagocyte engulfs

pathogenpathogen Breaks it down into Breaks it down into

its pieces or antigensits pieces or antigens Phagocyte Phagocyte

“presents” antigens “presents” antigens to helper Tcellsto helper Tcells

► This leads to…..This leads to…..

Clonal SelectionClonal Selection

►When there is a When there is a match between match between Tcell and antigen….Tcell and antigen…. Tcell divides and Tcell divides and

multiplies rapidlymultiplies rapidly Produces B Cells Produces B Cells

which will produce which will produce antibodies, and other antibodies, and other memory Tcellsmemory Tcells

AntibodiesAntibodies

► Produced by BcellsProduced by Bcells► Lock onto antigens Lock onto antigens

and signal them for and signal them for destructiondestruction

► Antibodies also Antibodies also deactivate antigensdeactivate antigens

Induced fitInduced fit

► Antibodies act similar to enzymesAntibodies act similar to enzymes Specific for what they work onSpecific for what they work on

►Not lock and key model, but induced fitNot lock and key model, but induced fit

Immunological MemoryImmunological Memory

►Antibodies will remain in the Antibodies will remain in the bloodstream and circulate looking for bloodstream and circulate looking for their specific antigentheir specific antigen

►Memory cells will also continue to Memory cells will also continue to circulatecirculate

VaccinesVaccines

►Genetic material from a pathogen is removedGenetic material from a pathogen is removed► Injected into bodyInjected into body► Body produces antibodies against pathogenBody produces antibodies against pathogen► Body now has memory cells against pathogenBody now has memory cells against pathogen

Disorders of the Immune Disorders of the Immune SystemSystem

►Three major typesThree major types ImmunodeficiencyImmunodeficiency AutoimmunityAutoimmunity HypersensitivitiesHypersensitivities

ImmunodeficiencyImmunodeficiency

►When one or more components of the When one or more components of the immune system are missing or inactiveimmune system are missing or inactive

►Ability to respond to pathogens is Ability to respond to pathogens is diminisheddiminished

►CausesCauses ObesityObesity AlcoholismAlcoholism Nutrient deficiencyNutrient deficiency

AIDSAIDS

► Acquired Acquired ImmunodeficiencyImmunodeficiency Attacks ability to Attacks ability to

produce lymphocytes produce lymphocytes that are crucial to the that are crucial to the immune responseimmune response

With out these cells With out these cells patient becomes patient becomes susceptible to susceptible to oppurtunistic oppurtunistic infectionsinfections

AutoimmunityAutoimmunity

►When immune When immune system fails to system fails to recognize difference recognize difference between self and no between self and no selfself

► Ex: Systemic LupusEx: Systemic Lupus Immune system can Immune system can

attack any part of attack any part of the bodythe body

Heart, Lungs, Joints, Heart, Lungs, Joints, Blood Vessels, Liver, Blood Vessels, Liver, KidneysKidneys

HypersensitivitiesHypersensitivities

►The immune system has decided to The immune system has decided to produce a respond to an antigen that produce a respond to an antigen that is not dangerousis not dangerous

►ex:ex: Food allergiesFood allergies Seasonal allergiesSeasonal allergies