There is a new bug is sweeping the area, the symptoms are flu-like, may involve the GI and CNS systems, possible encephalopathy in a few cases. In the extreme, there have been reports of incidences of anaphylaxis upon second exposure. What is known is that it appears to be systemic. Mucus secretions from an individual that has successfully cleared the infection can reduce the infectivity of the “bug” in culture. The bug can be cultured. Mucus secretions from a host that is naïve, does not affect the virulence of the “bug”. Serum from individual’s displaying the array of symptoms is available.
We need diagnostic tests:
1. What immunoglobulins are you going to look for and why? Remember, we know it is systemic, the mucus has neutralizing properties and there appears to be an anaphylactic response possible:
2. Do you think the ability of the mucus to block infectivity is adaptive or innate? Explain your reasoning.
3. Why do you think there is anaphylaxis?
4. How could you enrich serum for Ig specific to the bug?
5. How could you prepare “bug” antigens?
6. Design assays for all the Ig’s you listed in question 1. (include controls needed!!)
More space to diagram your Ig assays.
7. How would you determine if there were NK or Tc involvment in the clearing of the infection?
Verified Expert
1. The immune-globulins to look for would be IgA, IgG and IgE. Secretory IgA acts as an important effector function at mucous membrane surfaces. These mucous membrane surfaces act as the main entry sites for most pathogenic organisms. By virtue of being polymeric, IgA cross links large antigens with multiple epitopes. Viral as well as bacterial infections are prevented when IgA binds to viral and bacterial surface antigens.
The IgG is the predominant class forming a maximum of 75% of the total immunoglobulin. It is produced as a secondary immune response to an antigen. It is associated with flu like symptoms and encephalopathy as well.
On the other hand, IgE antibodies mediate the immediate hypersensitivity reactions which are responsible for hay fever, asthma, hives as well as anaphylaxis. The primary role of IgE is to identify particular parts of harmful substances, known as antigens. The mast cells release inflammation causing substances like histamine, whenever there is a cross linking of IgE molecules.