Immunologist ___________________________
Date ______________
Immunological Malfunction? Reading Questions
Immunoglobulins
Background Information
Immunoglobulin is a type of protein that helps the body fight disease. Immunoglobulin,
abbreviated at Ig, is also referred to as antibody. The substance is located in various parts of the body,
depending on the type of immunoglobulin it is and its function. There are five different forms of the
antibody, each with a particular job.
IgA is located in the respiratory and digestive tract, the nose, ears, eyes, and vagina. IgA is
responsible for protecting the body from outside invaders. It is found in saliva, blood, and tears. IgG is
the smallest form of immunoglobulin, and is located in all body fluids. It is responsible for fighting
bacterial and viral infections, and is the only antibody that crosses the placenta to protect a fetus
during pregnancy.
IgM is the largest antibody. It is the first responder to infection, and is located in the blood and
lymph fluid. Along with mounting an initial response to foreign bodies, IgM also encourages other
immune system cells to fight the infection. IgD is located in the tissues of the torso and chest, and
researchers have not determined its function.
IgE is located in the various mucous membranes, in the skin, and the lungs. IgE is responsible for
the body's reaction to allergens such as pollen, fungus, dander, and spores. It may also trigger allergic
reactions when exposed to milk, medications, and poisons. People who suffer from allergies often have
high levels of IgE.
http://www.wisegeek.com/what-is-an-immunoglobulin.htm
1. List the different immunoglobulin types and explain where they are found and what their
functions are.
2. Looking over this list, do Daniel’s recurrent lung infections make sense? Why?
Isotype Switching (Use pgs. 1015-1016 for help)
3. What is an antigen? How does this help to fight an infection?
4. What is an antibody? How does this help to fight an infection?
5. What are lymphocytes? How do they help fight infection?
6. Are antigens and antibodies a specific or non-specific defense?
Pedigree (Use pg. 395 for help)
7. What is an X-linked genetic disorder?
8. Why did the genetic counselor suggest their daughters also be tested?
CD40 (Use pgs. 1016-1019 for help)
9. What is humoral immunity?
10. What is cell-mediated immunity?
11. How do T cells and B cells work together to defend your body against pathogens?
Treatment or Cure?
12. How can a bone marrow or cord blood stem cell transplant cure Daniel?
Home Again
13. Should they undergo prenatal testing (Testing a developing fetus before birth to determine if
it has a certain genetic condition)? Why or why not?
14. Do you know a way in which Susan and Joe would be able to select a child with matching
HLA (human leukocyte antigen)?