lecture 1 immune system

8/17/2019 Lecture 1 Immune System

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Cells and Tissues of Cells and Tissues of the lymphoid systemthe lymphoid system


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The immune system consists of cells and tissuesThe immune system consists of cells and tissues

responsible for protecting the host from invadingresponsible for protecting the host from invading

microbes and self transformed cells.microbes and self transformed cells.

The protection (immunity) is achieved through theThe protection (immunity) is achieved through the

existence of an several specific and non-specificexistence of an several specific and non-specific

cells that respond to antigen-dependent signals.cells that respond to antigen-dependent signals.

The protection is further strengthened by theThe protection is further strengthened by thestrategic distribution of specialized organsstrategic distribution of specialized organs

throughout the body. These organs are thethroughout the body. These organs are the

secondary lymphoid organs, which function assecondary lymphoid organs, which function as

meeting places! for antigens and the immune cellsmeeting places! for antigens and the immune cellsto interact.to interact.

ConceptsConcepts


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"mmunity is the mechanism of protection."mmunity is the mechanism of protection. There are two types of "mmunity#There are two types of "mmunity#

"nnate (natural) $daptive (specific)"nnate (natural) $daptive (specific)

%orne with the host "nducable%orne with the host "nducable non specific &pecificnon specific &pecific'as no memory "mprove on second'as no memory "mprove on second

exposureexposure

&hort duration ong duration protection&hort duration ong duration protection

ConceptsConcepts


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"nnate and $daptive "mmune"nnate and $daptive "mmune

esponsesesponses


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The Cellular *layers of innate immunityThe Cellular *layers of innate immunity

*olymorphonuclear eu+ocytes (*s) and onocytes.*olymorphonuclear eu+ocytes (*s) and onocytes.

ingest antigens and destroy through powerful intracellularingest antigens and destroy through powerful intracellular

mechanisms.mechanisms.

*s are the first cells to arrive at a site of inflammation.*s are the first cells to arrive at a site of inflammation.

cells die once antigen is removed.cells die once antigen is removed.

monocytes enter sites of inflammation later differentiatemonocytes enter sites of inflammation later differentiate

into macrophages and enhance antigen clearance.into macrophages and enhance antigen clearance.

atural /iller (/) Cellsatural /iller (/) Cells

large granular lymphocytes li+e cells.large granular lymphocytes li+e cells.

recognize target cells through alterations of cells.recognize target cells through alterations of cells.

+ill target cells through cytolytic mechanisms.+ill target cells through cytolytic mechanisms.


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$c0uired immunity#$c0uired immunity#

'umoral and Cellular "mmunity'umoral and Cellular "mmunity


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The Cellular *layersThe Cellular *layers

ymphocytesymphocytes express antigen-specific receptors.express antigen-specific receptors.

mediate effector and regulatory influences.mediate effector and regulatory influences.

confer long-term immunological memory.confer long-term immunological memory.


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ymphatic &ystemymphatic &ystem


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*rimary ymphoid 1rgans*rimary ymphoid 1rgans

&ites where cellular components of immunity are generated.&ites where cellular components of immunity are generated.

*recursor cells are generated in the fetal liver during prenatal*recursor cells are generated in the fetal liver during prenatal

development.development.

*recursor cells are generated in the bone marrow postnatally.*recursor cells are generated in the bone marrow postnatally.

% lymphocytes (antibody production) mature exclusively in% lymphocytes (antibody production) mature exclusively in

the bone marrow.the bone marrow.

T lymphocytes (damaged cell recognition) mature in theT lymphocytes (damaged cell recognition) mature in the

thymus.thymus.

atural +iller (/) cells (damaged cell recognition) mature inatural +iller (/) cells (damaged cell recognition) mature in

the bone marrow.the bone marrow.

yeloid cells ($*C precursors) mature in the bone marrow.yeloid cells ($*C precursors) mature in the bone marrow.


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'aematopoiesis'aematopoiesis


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aturation of the yeloid Cellaturation of the yeloid Cell

ineageineage


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ymphocyte aturation


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&tructure of the Thymus&tructure of the Thymus


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&econdary ymphoid Tissues&econdary ymphoid Tissues

*eripheral ymph odes*eripheral ymph odes

connected to lymphatic networ+.connected to lymphatic networ+.

drain peripheral tissues migration of antigen ordrain peripheral tissues migration of antigen or

$*Cs into the lymph node.$*Cs into the lymph node.

compartmentalized to optimize antigen lymphocytecompartmentalized to optimize antigen lymphocyteinteractions.interactions.

&pleen&pleen

acts as a filter of antigen from the blood.acts as a filter of antigen from the blood.

the white pulp! of the spleen is structurally similarthe white pulp! of the spleen is structurally similar

to peripheral lymph nodes.to peripheral lymph nodes.

also designed to optimize antigen lymphocytealso designed to optimize antigen lymphocyte

interactions.interactions.


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*eripheral ymph ode 2istribution*eripheral ymph ode 2istribution


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*eripheral ymph ode &tructure*eripheral ymph ode &tructure


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&pleen &tructure&pleen &tructure


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ucosal-associateducosal-associated

ymphoid Tissue ($T)ymphoid Tissue ($T)


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ucosal-associateducosal-associated

ymphoid Tissue ($T)ymphoid Tissue ($T)


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Cutaneous-associatedCutaneous-associated

ymphoid Tissueymphoid Tissue


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a3ve ymphocyte 4ntry intoa3ve ymphocyte 4ntry into

ymph odesymph odes

lecture 1 immune system

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