Concepts inSpecific Host Immunity

A preparatory guide toconcepts in

Adaptive Immunityto accompany the lecture sequence

By Noel Ways

BodyCellTc

HemopoieticStem Cells

MyeloidStem Cells

LymphoidStem Cells

Erythrocytes Thrombocytes Basophils Eosinophils Neutrophils Monocytes

Macrophages

B Lymphocytes(Humeral Immunity)

T Lymphocytes(Cellular Immunity)

Gas Transport & Hemostasis Nonspecific Host Immunity

Conferance ofImmunocompotence

in Bone Marrow

Conferance ofImmunocompotence

in Thymus Gland

SpecifcHost

Immunity

Plasma B CellsAntibodies

Memory B Cells

Helper T Cells

Cytotoxic T Cells

Regulator T Cells

Memory T Cells

HematopoiesisFlow Chart

Page 2

ImmunocompetentLymphocyte Cell Lines

“General”Somatic

Cell Lines

ImmunocompetenceDevelopment

Th Cells Tc Cells B Cells

GrowthandDifferentiation

Genetic recombination events of approximately 60 genes results in vast array of receptors in lymphocyte cell lines.

However, lympho-cytes competent to recognize “self” molecular structures instructed to apop-tose.

With their elimina-tion complete, an autoimmune response / disease is not possible.

This “Oxford Dic-tionary” of receptors are competent to recognize huge num-bers of cell surface structures including many “self” molecu-lar structures.

Lymphocytes that have not apoptosed will migrate to and colonize lymphatic organs and wait ever ready to attack any non-self entity for which each is immu-nocompetent.

Lymphatic Organs

Bone MarrowThymus Gland Thymus Gland

Page 3

Endogenous AntigenDisplay

ImmunocompotentTc Cells

Cancer Cell:• Abnormal protein synthesis

• Abnormal protein ( ) displayed with Class I MHC

• Tc Cell is immuno- competent against it

• Tc Cell instructs cell to apoptose

Healthy Cell:• Normal protein synthesis

• Normal protein ( ) displayed with Class I MHC ( )

• No Tc Cell is immuno- competent against it

• No autoimmune response

Virally Infected Cell:• Viral Life Cycle begins

• Abnormal protein synthesis

• Abnormal viral protein ( ) displayed with Class I MHC

• Tc Cell is immuno- competent against it

• Tc Cell instructs cell to apoptose

ViralBiosynthesis

Page 4

Exogenous Antigen Display

ImmunocompetentTh Cells

PhagosomeLysosome

Phagolysosome

Antibody-antigencomplexes form

Plasma Cells

Antibodies

ClonalProliferation

• Immunocompotent Th Cell binds to Class II MHC / Antigen complex

• If the APC is a B Cell, Th cell will induce B cell differentiation into Plasma B cells, which then clonally proliferate and produce antibodies.

Page 5

• Phagocytosis

• Antigen processing within phagolysosome

• Antigen ( ) displayed in conjunction with Class II MHC ( )

• Cell is now an “Antigen Presenting Cell” Examples: Macrophages, Dendritic Cells, B Cells

Exogenous Antigen Display (Part 2)

ImmunocompetentTh Cells

ImmunocompetentTc Cells

Phagosome

Lysosomes

Phagolysosome

“Cast of Characters in the Immune Drama”

Th

Tc

Tr

Tm

B

Bp

Bm

Page 7

** In Progress **

Endogenous Antigens are made in the Cell Displayed in conjunction wtih Class I MHC Cytotoxic T Cells will respond to Class I MAC They can instruct your cell to Apoptose They can cause apoptosis of body cell

Exogenous Antigens are made outside of the Cell Displayed in conjunction wtih Class II MHC Helper T Cells and B Cells will respond to Class II MHC This will lead to antibody production and the destruction of pathogenic bacteria They can lyse offending bacteria

B

B

Th

AntibodiesDestroy Pathogen outside of body

TcTc

Induces ApoptosisDestroys Cell with pathogen within