For each of the following, identify the antibody or antibodies (if more than one
ID: 253315 • Letter: F
Question
For each of the following, identify the antibody or antibodies (if more than one) that meet each of the following criteria. Briefly (about one sentence or less) answer the follow-up question.
f)________ Used to prevent Rh- moms from being sensitized against an Rh+ baby. Briefly explain how this type of hypersensitive reaction could kill subsequent babies.
g)________ Found on the surface of a naïve B cell. What is a “naïve” B cell?
h)________ Responsible for the allergic response What happens during the two exposures required for the allergic response? (>1 sentence is OK)
i)________ Used in artificial passive immunizations What is the difference between “active” and “passive” immunity? State some examples
Explanation / Answer
f. Anti-D (anti-Rh) antibodies are used to prevent Rh-negative moms from being sensitized against Rh-positive babies.
Explanation: Anti D antibodies bind to Rh antigens present in the maternal blood. Hence, the Rh factor from fetus are neutralized and will not cause a hypersensitivity reaction in subsequent pregnancy.
Answer to Question (one sentence): In subsequent pregnancies, Rh negative moms develop antibodies to Rh (Rheusus) antigen that cross the placenta and react with red blood cells of the mother, killing them resulting in hypersensitivity reaction.
g. IgM and IgD antibodies are expressed on the surface of naïve B cells.
IgD is monomeric immunoglobulin is expressed when immature B cells expressing IgM are differentiated into naïve cells. Its expression is abrogated when these naïve cells are activated by binding of antigen.
Answer to Question (one sentence): Naive B cells are B cells that are not exposed to any antigen.
h. IgE antibodies are responsible for allergic response.
IgE is one of the five antibodies produced by the B cells of immune system. It does not activate complement. It binds to the IgE receptor present on the surface of the mast cells to initiate a allergic response.
Answer to Question (> one sentence):
When an allergen first enters the body, the allergen contacts the B cells that differentiate and produce IgE antibody. The IgE is released into the bloodstream. It binds to Fc receptors on mast cells and basophils, sensitizing the sensitized, and await the second exposure. When the allergen contacts the second time, it binds to the IgE present on mast cells. The mast cells degranulate and release histamine, slow reacting substance of anaphylaxis (SRS-A), heparin, prostaglandins, platelet-activation factor (PAF), eosinophil chemotactic factor of anaphylaxis and proteolytic enzymes. These proteins trigger inflammation and other processes such as smooth muscle contraction, increased vascular permeability and mucous secretion.
i. IgG antibodies are used for artificial passive immunization.
IgG antibodies can pass the placental barrier. It is the most abundant antibody is produced and can protect against bacterial and viral infection.
Answer to Question:
Active immunity is generation of an adaptive immune response after exposure to an antigen, while passive immunity is the injection of short lived antibodies from another person or animal either naturally or artificially to combat an infection . Example of active immunity: Infection with hepatitis A virus generates and active immunity. Chickenpox viral infection leads to generation of an adaptive immune response.
Example of passive immunity: maternal tetanus Ig antibodies provide passive immunity to newborn. Hepatitis B IgG antibodies provide passive immunization against hepatitis B virus. Colstrum or first breast milk provide passive immunity to the newborn.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.