Something to think about

If you meet a very anxious mom of a young child at the local clinic and, on asking as what the medical problem of her child is, you get told: "She has a temperature", describe clearly what is wrong in that statement.
Sent via my BlackBerry from Vodacom - let your email find you!

"This e-mail is subject to our Disclaimer, to view click http://www.dut.ac.za"

immunology project 2011

Hi guys

I thought that I should give you a preview of what you will be expected to do in your immunology project this semester. I had another project in mind but due to the lost lecture time, I have had to make changes.

 

So I hope that all of you are familiar with youtube and have at least watched one video on the site. I also hope that you have access to a cellphone that has video recording capabilities. So you will video yourself describing a concept or procedure relevant to immunology and upload it to YouTube. I will download the video and after watching it, assess it using a rubric that you will be given shortly. So I guess you have to start sharpening your speaking skills and start doing some research. More details about the project will be provided once I see you. Good luck guys!

---

"This e-mail is subject to our Disclaimer, to view click http://www.dut.ac.za"

the specific immune response

characteristics of the specific immune response
1. specificity
IR is specific for specific Ag or specific component of Ag; epitopes/determinants = portion of Ag recognized by lymphocytes

2. memory
IS remembers Ag; therefore the second response = quicker, more intense

3. self regulation
feedback regulation of IR; normal IR wanes/decreases after time, return to dormant state

4. diversity
lymphocytes can respond to a very large number of Ag

5. distinguish self from non self i.e. recognizes foreign
IS can distinguish between foreign and self Ag (define self Ag)


The specific immune response has 2 components
1. primary IR
2. secondary IR


primary response
This can be illustrated in a graph showing the different stages as described below

specific Ab appear in blood after 3 – 14 days
latent period (lag phase) involves Ag recognition and development of lymphocyte clones
log phase shows a rise in [Ab] logarithmically until it reaches a peak
IgM is the principal Ab synthesized.
decline phase depicts a drop of [Ab] to very low levels

primary response vs secondary response
(Features of secondary IR that are different to primary IR)

1. more rapid than primary response
2. shorter latent period
3. decreased amount of Ag needed to invoke response
4. more Ab produced
5. decline phase is slower
6. predominant Ab is IgG
7. affinity of Ab increases

remember the above differences as we will be doing an in class exercise using this information.

questions for all students (mainstream and extended group)

Classify the following as either specific, non specific, primary, secondary, non immunogenic:

IV injection of penicillin; Anti diarrhoeal tablets; Inflammation; Sore throat
Fever; Sinusitis; Hay fever; WBC; neutrophils; urine; tears; lysozyme; tea; allergy; no symptoms on exposure to German measles; HIV; AIDS; food; lactose in lactose intolerant people;

lock and key mechanism contd

I can see that a few students are having a problem understanding this concept. Unfortunately I cannot add a picture to this blog. However I have asked you to consult with your matric life science notes. Or you can visit your local library and use their school textbooks or you could search the net. Don't be lazy people, use your initiative

http://www.biologyguide.net/unit1/2_enzymes.htm

http://www.chem4kids.com/files/bio_enzymes.html

try the websites above

APC's

So how many of you read Victorian novels/romances? Yeah I suppose not many of you are readers, right??? Okay so have any of you watched a like really old movie like Gone with the Wind? where debutantes were presented to society as having learnt all the social graces and are ready for marriage. Obviously all the eligible (rich and handsome helps here) bachelors were invited to these occasions. Rather like a cattle sale, I think..... women for sale (marriage) and men (buyers) on the lookout for the best. Sp how far have we come in South Africa with our interpretation of the debs ball??????
These women were presented and the bill paid by rich relatives, usually old dowager ladies.
So anyway the point I am trying to make here:
APC's (Ag presenting cells) are rather like these old ladies. They present Ag to immune cells (or the immune system) for processing. In most cases ( we will do exceptions later on), Ag will not stimulate an immune response without an APC. Now and APC is not a particular type of cell, but rather a function carried out be specific cells. B cells, monocytes, macrophages, phagocytes, neutrophils, dendritic cells all act as APC's.

who are you?

Hi
I have noticed that this blog is being viewed by people other than my intended audience. I have no problem with this. However, I would really appreciate you maybe introducing yourself to me and telling me what benefit you are deriving from this blog. I promise to keep all information confidential. Could you also tell me what field you are involved in?
warm regards
Sherlien

classification of specific immune responses

they can be divided into active or passive immunity, and natural or artificial immunity.
in active immunity, energy is expended or used up in creating antibodies. In passive immunity, antibodies are "inherited" or sourced from outside the host's immune system. In a natural immune response, things happen as consequences of day to day living. Artificial immunity refers to us forcing something to take place.
examples:
getting the flu, and recovering is active and natural
immunization is active and artificial
placental transfer is passive and natural
administration of antitoxin is artificial and passive

can you justify the above?
what is the difference between immunization and administration of antitoxin?
what is an antitoxin and in what way does it differ from an antibody?

FACTORS INFLUENCING IMMUNOGENICITY CHEMICAL NATURE OF IMMUNOGENS

A. Proteins -The vast majority of immunogens are proteins. These may be pure proteins or they may be glycoproteins or lipoproteins. In general, proteins are usually very good immunogens.
B. Polysaccharides - Pure polysaccharides and lipopolysaccharides are good immunogens.
C. Nucleic Acids - Nucleic acids are usually poorly immunogenic. However, they may become immunogenic when single stranded or when complexed with proteins.
D. Lipids - Lipids are non-immunogenic, although they may be haptens.

question
add these differences to the table you created in the previous post.
Write up the answers/table clearly, with your name and reg no, and bring to class when lectures begin, for assessment.

FACTORS INFLUENCING IMMUNOGENICITY Contribution of the Immunogen

1. Foreignness - The immune system normally discriminates between self and non-self such that only foreign molecules are immunogenic.
2. Size - There is not absolute size above which a substance will be immunogenic. However, the larger the molecule the more immunogenic it is likely to be.
3. Chemical Composition - The more complex the substance is chemically the more immunogenic it will be. The antigenic determinants are created by the primary sequence of residues in the polymer and/or by the secondary, tertiary or quaternary structure of the molecule.
4. Physical form - Particulate antigens are more immunogenic than soluble ones and denatured antigens more immunogenic than the native form.
5. Degradability - Antigens that are easily phagocytosed are generally more immunogenic. This is because for most antigens (T-dependant antigens) the development of an immune response requires that the antigen be phagocytosed, processed and presented to helper T cells by an antigen.

question
tabulate the differences between immunogenic and non immunogenic for each of the factors described above