Transcript The Human Immune System: Basics and then some…

The Human Immune
System:
Basics and then some…
Basic Components of the Immune
System
• Pathogen, Bacteria, Viruses, Infections,
and parasites
• Leukocytes
• Antibodies
• Antigens
Virus
Pathogens and all the other stuff
• Any biological agent that causes illness and/or disease
to its host. Also known as a germs, simple as that!
Different types of pathogens
include the following:
White Blood Cells
Other Types of
WBC
lymphocytes
T cells
B Cells
Leukocytes
(White Blood Cells)
NK Cells
Eosinophils
Macrophages
Eosinophils and Macrophages
Eosinophils are a type of White
Blood Cell.
• Macrophage, “Big Eaters,” a form of
White Blood Cell.
They fight infection and parasites.
• Operates in both the Non-specific
They also play a role in Allergic
and Specific Immune Systems (to be
reactions.
explained later)
Eosinophils produce Interleukin 1
• Also a Phagocyte, which means it
and Interleukin 2 (To be explained
engulfs pathogens and cellular
later as well).
debris, and then proceeds to digest
it, this process is known as
Phagocytosis.
Macrophage!
Antibodies & Antigens
whenor
stimulated
• Antibodies
Antigens=area produced
fragmentbyofB acells,
protein
peptidebyfrom the
lymphokines from helper T cells. The antibody attaches to the
pathogen,
taken the
to the
surface
infected
antigen,
completing
signal,
codingof
thethe
infected
cells cell
for and
bound in .an MHC (major histocompatibility complex)
destruction
molecule.
Antibodies
are constructed of DNA fragments, making them so unique
innumerable.
• and
Thealmost
class
1 MHC complex molecule and the foreign
peptide form the antigen, which can be read by the
receptors on Killer T cells.
Antigen
Cell
Class 1 MHC molecule
Pathogen
Helper T cells- secrete
lymphokines that direct B cells
into producing antibodies and
also direct the Killer T cells as to
which cell they get to eliminate.
T cells!
Helper T cell (Th)
Killer T cells- They find
specifically coded infected
cells, and then destroy them
T cells with cytotoxins. They may be
directed by Helper T cells
Killer T cell (Tk)
Memory
T cellsMemory
T cellderived
Suppressor T cell
from Helper T cells,
have the same
properties as their
Suppressor T cells- in charge
Helper
T
cell
parent cell, and
of slowing and stopping the
circulates until the body
immune response after the
encounters the
foreign substance is destroyed.
pathogen its parent cells Killer T cell
were designer for.
B cells
•
•
•
•
B Plasma Cells- when the B cell
produces the antibody for a
specific antigen, it begins to clone
itself into B plasma cells, that
produce more of that particular
binding antibody.
These cells release
immunoglobulin, or antibodies.
B plasma cells have a 5 to 7 day
life-span
all its protein synthesis energy is
going into the production of
Antibodies, not self preservation.
•
B Memory Cells- These are the
same as B plasma cells, except
they remain inactive until the
secondary immune response
•
Secondary immune response is
considered anytime the body
encounters a pathogen after the
first time. Quicker response time.
•
Primary response is the first time
the body encounters a specific
pathogen, Lag period before B
cells respond.
NK Cells
• NK, stands for Natural Killers, meaning they do not need
to be activated by a class 1 MHC receptor
• NK cells play a major role in the Innate Immune System
• Activated by interferons and macrophage-derived
cytokines
• Contains a virus until killer T cells develop, and then kills
the virus.
Now, the pieces come together…
Immune System
Non-specific Response
Complement System
Interferon Response
Inflammatory Response
Fever Response
Specific Response
Anti-body Mediated Response
Cell Mediated Response
Non-Specific Immune Response
•
Also Known as the “Innate Immune
System
• Consists of:
Complement system, and three response
types:
Fever Response,
Inflammatory Response,
Interferon Response
Inflammatory Response
•
•
•
•
Occurs from Trauma.
Releases Bradykinin
Bradykinin
is
a
protein
Causing release of histamines.
that stimulates pain
Histamine causes increased capillary
sensors
as
well
as
causing
dilation, subsequently increasing capillary
the release of histamines
permeability.
• Increase in fluids causes inflammation!
Interferon Response
• As the name suggests, they
interfere…with viral replication!
• Once the virus infects the cell, the cell
creates a chemical protein called
Interferon!
• Interferon inhibits viral reproduction
between cells by binding to the receptors
of uninfected cells.
Fever Response
• The response to toxins in the body, produced by
bacteria, is to increase the internal temperature of the
body.
• This affect is enhanced when cells release Pyrogen, a
cytokine that resets the bodies temp. Also known as
Interleukin 1!
Complement System
• Main component of the Innate Immune
System
•Complements
3 primary
ways
to
dispose
of
pathogens.
can kill bacteria by punching a hole into their lipid
1.)Chemical stimulation causes the complement protein to bind with any
cell, like bacteria. Binding triggers activation of other complements, as
well as attracting phagocytes.
membrane and essentially drowning them in water.
2.) Some cells have sugar (polysaccharide)
capsule shells, complement can’t directly bind.
So they’re either eaten by macrophages, or 3)
bound to a macrophage that then releases
Foreign IL-6,
IL-6 goes to the liver and produces aCell
protein
called Mannose. Mannose binds to the bacteria,
allowing a complement to bind to it as well.
Interleukins
Of Note: Interleukin 1, 2, and 6
• AInterleukin
form of1: cytokine, they act like
-Responsible
for fever response
neurotransmitters
for the immune system,
Interleukin
6:
-Controls some lymphocytes
-Secreted
by macrophages,
and sent to liver to
relaying
messages.
-Increases the
number of bone marrow cells
produce Mannose, which is a protein that binds
-Causes degeneration of joints between bones
to sugars.
-Interleukin
Helps with2:inflammation, especially from burns
-Key in discriminating between Self and foreign cells
-Secreted by the binding of T cells to an antigen
- Stimulates growth, differentiation, and survival of killer T cells.
Specific Immune Response
• Also known as “Adaptive Immune System”
• Breaks down into two categoriesAntibody- Mediated Immune Response
(AMIR)
Cell-Mediated Immune Response (CMIR)
Antibody Mediated Immune
Response
• Also known as Humoral Immune Response
• The antibodies secreted by the B cells in AMIR
attach to antigens and effectively “tag” specific
cells for destruction, sparing the lives of the
healthy cells.
Flow of AMIR
Macrophages roam body, engulfing infected extracellular materials
Degrades engulfed material into peptides
Class 2 MHC presents the infected peptide
As an Antigen
Antigen received by Helper T cells
Macrophage returns to lymph nodes w/ antigen
Th Cells secrete lymphokines
Lymphokines direct B cells to release antibodies
And directs Tk cells to infected cells.
Tk kills infected cells tagged by antibodies
Flow of CMIR
Host cells carry class 1 MHC molecules to outside of cell
MHC binds to and displays peptide/protein fragment of pathogen
Antigen recognized by Killer T cell antigen receptors
Parasite and MHC form antigen
Killer T cell releases cytotoxins into infected cells, and kills them
Immunological Memory
• Vaccination
The reason why
make
is anvaccines
introduction
of sense,
a
and we eventually
build a tolerance
dormant
or dead pathogen,
which to
certainare
diseases…
allows
body to do its primary
immune response without the risk of
It’s because after every encounter with a
pathogen,
bothsickness.
the T cells and the B cells
actual
differentiate into an inactive form of their parent
cell. They remain inactive until the second
immune response for that specific pathogen.
Allergic reactions
• The allergy is the immune systems
response to a harmless foreign substance,
such as pollen or dust.
• Since the immune system is based
primarily off of DNA, then it can be inferred
that allergies are hereditary.
Self vs. Not Self
• Like most systems things can go wrong, such as when the immune
system attacks itself, not recognizing the proteins that code a cell as
“self.” When this happens it is known as an autoimmune disease.
• In the case of tissue implants, they may be rejected if the tissue cells
don’t have the proper proteins to inactivate the complement system
in a different humans body. So the complement kills the cells!
• In order for tissues to be accepted they also must have the proper
MHC complex to pass as human cells, these proteins must be on
the surface of the cells, as either of the two classes.
The Immune System presented differently
Immunological
memory
CMIR
AMIR
Bibliography-Information
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http://www.mmu.k12.vt.us/teachers/kefferm/humanbio/immune/how%20cells%20process%20Ag.pdf
http://www.mmu.k12.vt.us/teachers/kefferm/humanbio/immune/white%20blood%20cells%20writing.jpg
http://en.wikipedia.org/wiki/Immune_System
http://en.wikipedia.org/wiki/Pathogen
http://en.wikipedia.org/wiki/Cell-mediated_immunity
http://en.wikipedia.org/wiki/Humoral_immune_response
http://en.wikipedia.org/wiki/Cytokine
http://en.wikipedia.org/wiki/Interleukins
http://en.wikipedia.org/wiki/Interleukin_1
http://en.wikipedia.org/wiki/Interleukin_2
http://en.wikipedia.org/wiki/Lymphokine
http://en.wikipedia.org/wiki/Eosinophil_granulocyte
http://en.wikipedia.org/wiki/Natural_killer_cell
http://en.wikipedia.org/wiki/Lymphocyte
http://en.wikipedia.org/wiki/Macrophage#Phagocytosis
http://en.wikipedia.org/wiki/Allergy
The Human Biology Text book by Joseph Mannino
http://uhaweb.hartford.edu/bugl/immune.htm
http://en.wikipedia.org/wiki/Antibody
And many, many, many, many other wikipedia pages…
Bibliography-Pictures
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https://services.epnet.com/GetImage.aspx/getImage.aspx?ImageIID=2508
http://www.mmu.k12.vt.us/teachers/kefferm/humanbio/immune/how%20cells%20process%20Ag.p
df
http://mmsmineraldrops.com/images/pathogens3.jpg
http://en.wikipedia.org/wiki/Lymphocyte
http://www.bio-pro.de/imperia/md/images/artikelgebunden/stern/nk_tumor_338x319.jpg
http://uhaweb.hartford.edu/bugl/immune.htm
http://tell.fll.purdue.edu/JapanProj/FLClipart/Verbs/fever.gif
http://static.howstuffworks.com/gif/light-virus-1.jpg
http://www.lipidnutrition.com/Images/MPE_059_gs%20copy%20adjusted%20pixels_tcm73751.jpg
http://pathology.emory.edu/images/FacultyImages/CooperM.jpg
http://www.gtdtimes.com/files/2008/05/memory.jpg
http://upload.wikimedia.org/wikipedia/commons/4/4a/Hematopoiesis_simple.png
http://www.modernforager.com/blog/wp-content/uploads/2008/03/96500b.jpg
Words of the Day!
• Erythropoietin- glycoprotein that controls
red blood cell production.
• Haematopoiesis- the process of making
blood cells from hematopoietic stem cells.
• Agammaglobulinemia- the inability to
make antibodies
And then there’s this guy…