MLS Immunology/Serology

Antigen

foreign substance that induce host response

• something immune sys responds to

• doesn’t have to be living thing

• ex: dust, food, pollen

Antibody

protein molecule produced by certain lymphocytes in response to exposed to ag

• Antigen → stimulate response → Ab

Attenuation

process of making pathogen less virulent. weaken pathogen

• deliberately expose to individuals to stimulate response

• via heat, aging, chemical

• vaccines use attenuated orgs : pathogen that is viable but less virulent

  • stimulant immune response without causing infection/make sick

Hapten

small molecule bind to ab but doesn’t stimulate immune response itself

• antigenic but too small to be immunogenic alone

Adjuvant

substance added to vaccine to enhance immune response to ag

• boosts immune response

Opsonization

make microbes more attractive/easier for phagocytes to interact with

• coats/tags microbes so phagocytes can recognize/grab it

• speeds phagocytosis process

• process that facilitates contact bw microbes and phagocytic cells

• acute phase reactants participate in this

Cytotoxicity

ability to kill/destroy target cells

• Ex: NK cells - recognize abnormal/infected cell → release perforins and granzymes to eliminate/cause apoptosis (death)

Antibody Dependent Cellular Cytotoxicity - ADCC

when target cell coated with Ab, and immune cell binds to Ab and kills target

• mechanism for initiating killing of infected host cell

1. Foreign Particles on surface

2. Ab recognizes/binds those proteins

3. NK uses CD16 receptor to bind Ab

4. NK releases perforins and granzymes

5. Target cell undergo apoptosis

Ab tags cell → NK cell recognizes ab and kills

Chemotaxis

movement of cells toward chemical concentration gradient

• chemical signal tells cells where to go

• infection occurs → chemical messengers released → wbcs move toward infection by following signals

Pathogen Associated Molecular Pattern - PAMP

molecular component/pattern found on microorganisms that can be recognized by host PRRs

• Ex: peptidoglycan in bacterial cell walls

  • detected by PRR → phagocytic cell become activated → inflammatory response begins

• pathogen’s “signal” , detectable pattern

Pathogen Recognition Receptor - PRR

receptor encoded by host DNA that recognizes PAMPS on microorgs

• PAMP on pathogen → PRR on host cell recognizes it → phagocytic cell activated → cytokines/chemokines released → more immune cells recruited

Host’s detector

Immunology

study of immune response

Serology

lab science involving in vitro use of ags/abs to aid in diagnosis of diagnosis and treatment of disease

• lab use, a lab test

  • “t” in vitro for “tube”

Immunogenicity

ability of substance to induce immune response

immunity

condition of being resistant to infection

Compare and contrast immunity, immunology and serology

immunity: condition, protection

immunology: study of

serology: lab testing

Compare and contrast innate and adaptive immunity

Innate Immunity	Both	Adaptive Immunity
Natural Present at birth acts immediately Nonadaptive: ability to resist infection w/ processes normally present at birth Ex: phagocytosis, inflammation	Protect against infection Can respond to pathogens	Acquired Develops after antigen exposure
Fully functional at birth	Involve immune cells	Specificity for antigens
Nonspecific responses are the same for ALL pathogen/foreign substances	Work together/interact Interdependent	Has memory
Does not require previous antigen exposure		Stronger response upon repeated exposure
Includes phagocytosis, inflammation, NK cells		BOTH humoral + cellular components
Affected by: age, hereditary, stress, fatigue, nutritional		B and T lymphocytes are major players

List and describe the cells of the innate immune system

>Blood Cells

Neutrophils

• function: phagocytosis → destroy microbes

• leave circulating blood via diapedesis in response to chemical msgers

Eosinophils

• increased in parasitic & allergic reactions

• phagocytic but DONT kill, not good at it

• release proteins that damage parasite mmbs

  • effective way to kill: granules contain proteins. when granules released, some parasitic cell mmb are destroyed by those proteins

• most important role: regulation of adaptive immune response via cytokine release

Basophils

• important role in allergic reactions

• granules contain histamine and heparin

  • histamine: contracts smooth muscle. bv enlarge, leakier

  • heparin: anticoagulant

• regulate immune responses

  • regulate T helper cell responses

  • stimulate B cells to produce IgE

Monocytes

• phagocytic

• become macrophages or dendritic cells in tissues

>Tissue Cells

Macrophages (big eaters)

• phagocytosis

• Microbial killing

• Antitumor activity

• Intracellular parasite eradication

• Secrete mediators

• Can act as ag presenting cells (APCs): capture ag, present to T lypmh → adaptive immunity

• diff names based on location

  • alveolar macrophage: lungs, kupffer cells: lungs, microglial cell: brain, osteoclasts: bone, histocytes: ct

Mast Cells (resemble basophils)

• Located in tissues

• Contain histamine, heparin, proteases, etc.

• role in allergic reactions

  • Increase vascular permeability and blood flow to affected areas

• Can function as APCs

• Link innate and adaptive immunity (enhance and suppress adaptive)

Dendritic Cells

• long mmbranous extensions, resemble nerve cell dendrites

• classified according to their location like macrophages

  • Ex: Langerhans cells in all layers of dermis/skin

• MOST EFFECTIVE APC, MOST POTENT PHAGOCYTIC CELL

• Capture antigen → Present antigen to T lymphocytes → Initiate adaptive immune response

• Strong connection between innate and adaptive immunity

NK Cells

• kill abnormal cells w/o prior exposure

• target virus infected and tumor cells

List and describe the cells of the adaptive immune system