Transcript immunesystem

Path of a
Pathogen!
Diseases
Michelle DAlleva
Jennifer
Cunningham
l
Michelle DAlleva
Antibodies
/ Vaccines
Catherine Flynn
Body’s
Defenses
Information on Path of Pathogen
The immune system is the body's defense against infectious organisms.
immune response- the immune system attacks the harmful organisms that
invade our bodies.
The cells that are part of this defense system are white blood cells, or
leukocytes. Two types:
1. phagocytes, cells that “eat” invading organisms
2. lymphocytes, “memory cells” that allow the body to remember and
recognize previous invaders and help the body destroy them
There are two kinds of lymphocytes: TEAM WORK!!!
1. B lymphocytes, “target” invading organisms for destruction.
2. T lymphocytes, destroy the invaders the “B” cells indentified
Path of a Pathogen Through the Body!
WATCH this funny presentation about the path of a
pathogen and then go on the the activity.
http://www.youtube.com/watch?v=3o3Iq-d6Roc
(Copy and Paste)
1. In the video presentation which two cells worked together
to identify and destroy the pathogen?
2. Humans have three types of immunity, explain each one;
innate, adaptive, and passive.
3. Antibodies activate a group of proteins called “complement”
to assist in the killing of what?
4. In the video presentation you saw a cell ingest and destroy
the invading pathogen. What was this cell’s name and what
process did use to destroy the pathogen?
Resource for help:
http://kidshealth.org/parent/general/body_basics/immune.html
Resources
1. Dowshen, Steven., MD “What the Immune System
Does.” Nemours Foundation Copyright November 2007.
http://kidshealth.org/parent/general/body_basics/immune.ht
ml
2. http://www.youtube.com/watch?v=3o3Iq-d6Roc
Disease Effect on the Immune System
AIDS – attacks cells that bear CD4 molecules on their surface, once inside a cell it reverse transcripts
itself and integrates the newly formed DNA into the host cell genome.
Allergies - are a result of an immune system that responds to a "false alarm." When a harmless
substance such as dust, mold, or pollen is encountered by a person who is allergic to that substance,
the immune system may react dramatically, by producing antibodies that "attack" the allergen.
Asthma - a respiratory disorder that can cause breathing problems, frequently involves an allergic
response by the lungs. If the lungs are oversensitive to certain allergens (like pollen), it can trigger
breathing tubes in the lungs to become narrowed, leading to reduced airflow and making it hard for
a person to breathe.
Burkitt lymphoma - is able to survive and ‘transforms’ the normal B-lymphocytes into cancerous cells.
The C-myc oncogene, it is responsible for the uncontrolled production of B-lymphocytes. It results
from a translocation, or exchange, of genetic material between the long arm of human chromosome
8 and the long arm of human chromosome 14.
Diabetes, type 1 - occurs when the body's immune system attacks and destroys certain cells in the
pancreas, these cells are beta cells which produce insulin.
DiGeoge Syndrome - is caused by a large deletion from chromosome 22, produced by an error in
recombination at meiosis.
Disease Review Sheet
What disease is a chronic inflammatory disorder of the airways?
What disease is a birth defect where children are born without a thymus gland?
Explain why the thymus gland is important.
Explain how HIV becomes AIDS and discuss how a newborn can have HIV.
How is the gene HGM-I/Y involved with the development of Burkitt’s lymphoma.
In type 1 Diabetes, explain what happens when beta cells are destroyed.
Sources:
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=gnd.chapter.51
http://www.kidshealth.com/parent/general/body_basics/immune.html
http://findarticles.com/p/articles/mi_gGEC/is_0010/ai_2699001070
Resources
Genes and Diseases, Diseases of the Immune System;
National Library of Medicine. Revised March 21, 2008
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=gnd.chapter.51
Steven Dawshen, MD “Immune System (Article)”. Nemours Foundation.
Kisdhealth.caom. November 2007.
http://www.kidshealth.com/parent/general/body_basics/immune.html
Ph.D. Rebecca J. Frey "Burkitt's lymphoma". Encyclopedia of Cancer.
none. FindArticles.com. 03 May 2008.
http://www.findarticles.com/p/articles/mi_gGEC/is_0010/ai_2699001070
University of Virginia “Allergies and the Immune System”. University of Virginia
Health System. Healthsystem.virginia.edu. 12 February 2004.
http://www.healthsystem.virginia.edu/uvahealth/adult_allergy/system.cfm
Juvenile Diabetes Research Foundation International “What is Diabetes?”. JDRFC
Jdrf.org. 2008.
http://www.jdrf.org/index.cfm?page_id=101982
Watch this presentation on the
Defense Mechanisms!
Then go to the activity!
http://www.youtube.com/watch?v=IQ_s4QUnCK0
(copy and paste)
• What is the 1st line of defense as shown in the video
presentation? Give three explains that were shown.
• What is the body’s 2nd line of defense as shown in the
video presentation? What is the inflammatory response?
• What is an interferon?
• What is the body’s 3rd line of defense as shown in the
video presentation?
·The Humoral Response- B cells make antibodies against
extracellular pathogens.
·Antigen- a foreign particle that enters the body.
·Antibody- a protein made by the immune system in response
to the invading antigen.
-They react with specific antigens (there is an antigenantibody complex based on shape)
-make up a group of globular serum proteins called
immunoglobins (Igs: IgM, IgA, IgG, IgE, IgD).
• Immunity- can be achieved naturally or artificially.
• Active Immunity- is dependent on the response of the infected person’s
own immune system.
-acquired by recovering from the infectious disease
(i.e. chicken pox)
-can be artificially acquired through a vaccine/immunization (inactivated
bacterial toxins, pieces of or killed/weakened microbes, or genes encoding
microbial proteins.)
• Vaccines- created to stimulate the body to produce antibodies against a
specific disease or antigen.
-Expose the vaccinated person to the disease and creates immunological
memory.
-The body remembers the antibodies and can make them faster if there is a
second exposure to the disease.
• Passive immunity- occurs when antibodies are transferred from one
individual to another (ex: from mother to fetus)
-Can be artificially transferred by injecting antibodies from an animal that
is already immune to a disease into another animal.
Types of Antigens
• May or may not need the help of helper T cells to trigger a
humoral immune response
-T-dependent antigens; ex: proteins
-T-independent antigens; ex: polysaccharides and proteins
with identical polypeptides
-helper T cells secrete cytokines, which activates
B cells that turn into plasma cells which secrete antibodies.
-1 plasma cell secretes appx. 2,000 antibody molecules per
second
• Antigens that spark a humoral immune response: protein
and polysaccharide surface components of microbes,
incompatible transplanted tissues/transfused cells.
• Antibodies bind to antigens in order to rid the cell of the antigen.
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Techniques:
viral neutralization- occurs when antibodies bind to proteins on the
surface of a virus and prevent a virus from infecting a host cell.
Opsonization- occupied antibodies increase the intensity of phagocytosis
and macrophage attachment to the antigen microbe.
Each antibody molecule has at least 2 antigen-binding sites.
-Allows immunoglobins to link microbes together to be phagocytosed by
macrophages.
Precipitation- is the cross-linking of soluble antigen molecules
-forms unmoving “precipitates” which are expelled through phagocytosis
Membrane attack complex (MAC)- formed by complement proteins
-forms a pore in the bacterial membrane
-ends in the lysing of the cell.
• The immune system’s ability to distinguish self from nonself
limits tissue transplantation
• Differences between ABO blood groups and the Rh factor can
result in rejection of blood transfusions
• Major histocompatibility complex (MHC) moleculesstimulate rejection of tissue grafts and organ transplants.
-creates unique protein identification for each human
-makes foreign MHC molecules antigenic.
Real A.P. Bio Question
The defenses of the human body to the entry and
establishment of a pathogen (disease-causing organism)
can be divided into nonspecific responses and specific
responses.
(a) Explain how THREE types of nonspecific defenses can prevent the
entry and/or establishment of a pathogen in a person’s body
(b) Discuss how the immune system responds to an initial pathogenic
exposure, and how this initial exposure can lead to a quicker response
following a second exposure to the same pathogen.
• (c) Explain the biological mechanisms that lead to the rejection of
transplanted organs.