midterm

specifically inherited in the genome (receptor characteristic)

innate

expressed by all cells of a particular type (receptor characteristic)

innate

triggers immediate response (receptor characteristic)

innate

recognizes broad classes of pathogens (receptor characteristic)

innate

interacts w/ a range of molecular structures of a given type (receptor characteristic)

innate

encoded in multiple gene segments (receptor characteristic)

adaptive

requires gene rearrangement (receptor characteristic)

adaptive

clonal distribution (receptor characteristic)

adaptive

able to discriminate between even closely related molecular structures (receptor characteristic)

adaptive

antibodies

bind to toxins and neutralize their activity

complement

component of serum that acts in conjugation w/ ab to destroy pathogenic bacteria

adaptive immunity is _

specific

innate immunity is _

nonspecific, engulfed and digested by phagocytic cells

hematopoietic →

myeloid

lymphoid

circulation in lymphatic system

drains extracellular fluid &immune cells from tissues and transfers them as lymph → emptied back into blood system

lymphocytes

recognize & target pathogenic microorganisms

categories of pathogens

virus

bacteria

archaea (fungi)

parasites

viruses kill by

inducing lysis during viral replication

intracellular/ mycobacteria kill cells by

directly or damaging cells by producing toxins

plasmodium (intracellular parasites) kill cells by

killing cells directly

parasitic worms/ helminths kill cells by

injuring tissues by forming cysts that induce cellular response

microbiome

archaea/ bacteria/ fungi but cause no damage (commensal)

avoidance

prevent exposure to microbes (anatomic barriers and behavior modifications)

resistance

reducing/ eliminating pathogens

eg effector mechanisms

tolerance

responses that enhance a tissue’s capacity to resist damage by induced microbes

both apative and innate immunity depend on

lymphocytes

mucosal surfaces produce a variety of

antimicrobial proteins that act as natural ABx

complement acts with

antibody to lyse bacteria

sensor cells

detect inflammatory induces through innate recognition receptors

innate recognition receptors encoded by genes

that remain constant

innate immune sensor cells produce

inflammatory mediators that act directly or on other cells

innate immunity is _ (time course)

rapid

adaptive immunity is _ (time course)

days but more efficient due to specificity of antigen recognition by lymphocytes

myeloid →

macrophages granulocytes, mast cells, dendritic cells

phagocytes are

macrophages, granulocytes, dendritic cells

macrophages are _

resident in all tissues

macrophages arise

during embryonic development but some arise from bone marrow in mature monocytes

monocytes

circulate in the blood and continually migrate into tissues

dispose pathogens and infected cells targeted by adaptive

induce inflammation

produce inflammatory mediators

monocytes are _

long-lived

most infections in tissues have more

macrophages > monocytes

local inflammation and phagocytosis can also be triggered by

complement scavenges → cleaning dead bodies/ debris

granulocytes

neutrophils, basophils, eosinophils

granulocytes are (survival)

short lived, only a few days

granulocytes mature in

bone marrow & production increases during immune response

neutrophils

phagocytic

destroy intracellular vesicles by degradative enzymes

most numerous innate immune response

neutrophils

eosinophils/ basophils

have granules containing a variety of enzymes & toxic proteins which are released when cells are activated

basophils/ eosinophils are important in

defense against parasites

allergic inflammatory reactions

mast cells develop in

bone marrow but mature in peripheral tissue (particularly skin, intestine, airway mucosa)

mast cell granules

contain inflammatory mediators such as histamine/ proteases → early sensors of infection/ initiation of inflammation

dendritic cells form in

bone marrow → migrate to tissue via blood stream

dendritic cells

phagocytosis

continually ingest large amounts of extracellular fluid (macrospinocytosis)

sensor cells → activate T lymphocytes of adaptive

adjuvant

intensify the response to the antigen

activate innate receptors on various types of sensor cells to help activate T cells in absense of infection

sensor cells

macrophages, dendritic cells, neutrophils

express PRRs which recognize PAMPs

NOD like

cytoplasmic proteins sense intracellular bacteria/ invasion

toll like receptors

detect PAMPS from extracellular bacteria or bacteria taken into vesicular pathways by phagocytosis

inflammatory mediators are

cytokines and chemokines

cytokines

protein secreted by immune cell that affect the behavior of nearby cells bearing appropriate receptors

approx 60

chemokines

secreted proteins that act as chemoattractants, attracting cells bearing chemokine receptors (neutrophils/ monocytes) out of blood stream → infected tissue organize lymphoid tissue into discrete regions where specialized responses can take place

inflammation

increase flow of lymph (carries microbes/ cells bearing their antigens from infected tissue to nearby lymphoid tissue) where adaptive response initiates

heat, swelling, redness, pain

increased permeability of blood vessels

endothelial cells also produce

cytokines

initial inflammatory response includes

macrophages/ neutrophils (also known as inflammatory cells)

monocytes differentiates

into macrophages

lymphoid progenitors →

NK cells

ILC (innate lymphoid cells)

NK cells

recognize/ kill tumor cells and cells infected w/ herpes virus

innate lymphoid cells

reside in peripheral tissue

mediators of inflammatory response

lymphocytes

T/ B lymphocytes

when T/ B lymphocytes have not been activated they are

naive

when T/ B lymphocytes have been activated they are

effector

have been differentiated

have met antigen

B cell receptor

same gene that encode antibody → Ig

antigen binds B cell receptor

B cell will proliferate and differentiate into plasma cells (effector form)

antigen binds T cell

proliferates into several types of effector T lymphocytes

types of effector T lymphocytes

cytotoxic T

Helper T

regulatory T

cytotoxic T cells

kill other cells infected w/ antigen

helper t cells

provide signals (cytokines) that activate other cells

regulatory T cells

suppress activity of other lymphocytes and limit damage of immune response

memory cells

some T/B cells → long lasting immunity

constant region

Fc

5 forms

variable region

Ab to recognize vast vantigens

antigen receptor comprised of

2 heavy chains and 2 identical light chain

variable region

antigen binding site

composed of heavy + light chain

constant region determines

effector

(function of AB)

T cell receptor

TCR alpha and beta chains

epitope

part recognized by antigen receptor

T cell receptor recognizes epitope

derived from a partially degraded protein but only if peptide is bound to specialized cell surface glycoproteins called MHC

Ig variable regions are inherited as

sets of gene segments

innate receptors

express many different PRRs

adaptive immunity receptors

each lymphocyte express one receptor specifically

antigen receptor expression is

clonal

each mature lymphocyte differs from others in specificity of Ag receptor → all progeny inherit the same receptor specific

lymphocytes are units of

clonal selection

clonal deletion

lymphocytes that are self reactive are removed before they can matture

anaergy

induction of inactive state

lymphoid organs

central

peripheral

central lymphoid organs are where

lymphocytes are generated

peripheral lymphoid organs are where

mature naive lymphocytes are maintained and adaptive immune responses are initiated

eg of central lymphoid

bone marrow

thymus

eg of peripheral lymphoid organ

lymph node

spleen

lymphoid tissue

lymph node goes to another lymph node via

lymphatic vessels

drain extracellular fluid from tissues, carry it through lymph node and deposit it back into blood

bone marrow produces

T cells

B cells