BIOL 1020 IMMUNOLOGY ASSIGNMENT

11 Jun BIOL 1020 IMMUNOLOGY ASSIGNMENT

Question
Immunology

Objectives

Understand the contents and origin of vaccines.
Discuss the relationship of the vaccine to primary and secondary immune responses of the body.
Evaluate the historical hypotheses that continue to be the working basis of immunization.

Introduction
The human body contains many B and T cells which together can respond to a multitude of antigens. Clonal selection theory explains the effectiveness in which the body can respond to an antigen. That is, there exists a variety of B cells within the human body each of which has a different kind of antigen receptor on their cell surface, and it is the activation of one of these that creates the selection for cloning. These B cells can produce effectors cells called plasma cells that will produce antibodies to fight this particular antigen. Plasma cells are short lived. These activated B cells will also produce memory cells, although at a much lower proportion, that can remain in the body for years. These memory cells can, when activated by the same specific antigen, divide quickly and produce more effectors.

Let us say that the body is exposed to a particular antigen for the first time. This antigen activates the lymphocytes to produce clones and in turn, these clones produce specific effectors and memory cells. Thus, the invader is destroyed and there are now memory cells of this specific invader. This is a primary immune response. The next time that the person is exposed to this particular antigen the response is much faster and will produce a higher level of antibodies. This secondary immune response is the direct result of memory cells produced during the primary immune response. It is because of these memory cells and their rapid response that we can immunize against diseases.

Vaccinations are simply the injection of small amounts of attenuated virus or bacteria or their protein into the body. This exposure to an antigen will cause the body to have a primary response that will not make them ill with the disease but will produce memory cells for that specific antigen. It is the production of memory cells that will protect the person against future illness since these B and T cells can quickly respond the invader and overwhelm it. During the late 1700s, an English physician named Edward Jenner observed that people, who had been ill with cowpox, would not become ill with smallpox, a related but much more harmful virus. He used cowpox to inoculate a small child in 1796. Later testing proved that the child was immune to both cowpox and smallpox. Although Jenner is given much credit for producing the first vaccine, there were others before him using the same principle to produce immunity

Laboratory ActivitiesExercise 1: Developing Immunity through Vaccinations

Protocol, Part I:

Read the historical documents from Lady Montague and Edward Jenner and answer the questions found on the data collection sheet that follows the historical information. Notice that the left side of the data sheet corresponds to the letter from Lady Montague and the right side to that of the journal entries of Edward Jenner.
PART ALetter from Lady Montague, 1717In 1717 Lady Montague arrived with her husband, the British ambassador, at the court of the Ottoman Empire (Modern day Turkey). She wrote much about her travels. The following is a letter that she sent to a friend back home in England.

A propos of distempers, I am going to tell you a thing that will make you wish yourself here. The small-pox, so fatal, and so general amongst us, is here entirely harmless, by the invention of engrafting, which is the term they give it. There is a set of old women, who make it their business to perform the operation, every autumn, in the month of September, when the great heat is abated. People send to one another to know if any of their family has a mind to have the small-pox; they make parties for this purpose, and when they are met (commonly fifteen or sixteen together) the old woman comes with a nut-shell full of the matter of the best sort of small-pox, and asks what vein you please to have opened. She immediately rips open that you offer to her, with a large needle (which gives you no more pain than a common scratch) and puts into the vein as much matter as can lie upon the head of her needle, and after that, binds up the little wound with a hollow bit of shell, and in this manner opens four or five veins. The Grecians have commonly the superstition of opening one in the middle of the forehead, one in each arm, and one on the breast, to mark the sign of the Cross; but this has a very ill effect, all these wounds leaving little scars, and is not done by those that are not superstitious, who choose to have them in the legs, or that part of the arm that is concealed. The children or young patients play together all the rest of the day, and are in perfect health to the eighth.

Then the fever begins to seize them, and they keep their beds two days, very seldom three. They have very rarely above twenty or thirty in their faces, which never mark, and in eight days time they are as well as before their illness. Where they are wounded, there remains running sores during the distemper, which I don’t doubt is a great relief to it. Every year, thousands undergo this operation, and the French Ambassador says pleasantly, that they take the small-pox here by way of diversion, as they take the waters in other countries. There is no example of any one that has died in it, and you may believe I am well satisfied of the safety of this experiment, since I intend to try it on my dear little son. I am patriot enough to take the pains to bring this useful invention into fashion in England, and I should not fail to write to some of our doctors very particularly about it, if I knew any one of them that I thought had virtue enough to destroy such a considerable branch of their revenue, for the good of mankind. But that distemper is too beneficial to them, not to expose to all their resentment, the hardy weight that should undertake to put an end to it. Perhaps if I live to return, I may, however, have courage to war with them. Upon this occasion, admire the heroism in the heart of

Your friend, etc. etc.

Source:

From Lady Mary Wortley Montague, Letters of the Right Honourable Lady M–y W–y M–e: Written During her Travels in Europe, Asia and Africa. . . , vol. 1 (Aix: Anthony Henricy, 1796), pp. 167-69; letter 36, to Mrs. S. C. from Adrianople, n.d.

PART A, II

JOURNAL ENTRIES OF EDWARD JENNER, 1796

CASE XVI

SARAH NELMES, a dairymaid at a Farmer’s near this place, was infected with the Cow Pox from her master’s cows in May, 1796. She received the infection on a part of the hand which had been previously in a slight degree injured by a scratch from a thorn. A large pustulous sore and the usual symptoms accompanying the disease were produced in consequence. The pustule was so expressive of the true character of the Cow Pox, as it commonly appears upon the hand, that I have given a representation of it in the annexed plate.

CASE XVII

THE more accurately to observe the progress of the infection, I selected a healthy boy, about eight years old, for the purpose of inoculation for the Cow Pox. The matter was taken from a sore on the hand of a dairymaid, who was infected by her master’s cows, and it was inserted, on the 14th of May, 1796, into the arm of the boy by means of two superficial incisions, barely penetrating the cutis, each about half an inch long.

…In order to ascertain whether the boy, after feeling so slight an affection of the system from the Cow-pox virus, was secure from the contagion of the Small-pox, he was inoculated the 1st of July following with variolous matter, immediately take from a pustule. Several slight punctures and incisions were made on both of his arms, and the matter was carefully inserted, but no disease followed. The same appearances were observable on the arms as we commonly see when a patient has had variolous matter applied, after having either the Cow-pox or the Small-pox. Several months afterwards, he was again inoculated with variolous matter, but no sensible effect was produced on the constitution.

…Thus far have I proceeded in an inquiry, founded, as it must appear, on the basis of experiment; in which, however, conjecture has been occasionally admitted in order to present to persons well situated for such discussions, objects for a more minute investigation. In the mean time I shall myself continue to prosecute this inquiry, encouraged by the hope of its becoming essentially beneficial to mankind.

Data Collection Sheet

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Letter from Lady Montague , 1717

Journal Entries of Edward Jenner, 1796

Note: Smallpox is a very contagious virus that causes swollen sores or “pox” on the skin. During the 1700’s, when this letter was written many died of smallpox particularly children

Background: Edward Jenner was an English Physician who worked in small farming villages during the late 1700’s.

1. Describe the actions of the women in the market.

1. With what did Sarah Nelmes become infected? And what in her daily routine exposed to this pathogen?

2. How often and when did they do this activity?

2. What symptoms did Jenner note?

3. What specifically happened to the person who received this treatment?

3. What did Jenner do on May 14, 1796?

4. Why would a person agree to have this treatment? Is there a benefit?

4. What did Jenner do on July 1, 1796?

5. Why do you think Lady Montague was so interested in the activity of the women in the market place?

5. What hypothesis do you think Jenner made and then tested?

When the human body is exposed to an antigen, the lymphocytes respond. One of these responses is to produce antibodies which will help eliminate the intruder. This first reaction to an invader is called the primary immune response and the cells that are producing the antibodies are short lived. However, a second set of cells are produced and they remember this particular antigen and can produce antibody when needed. These memory cells will respond when the body is invaded for a second or third or fourth time by the same invader. In fact these memory cells remain in the body for many years following the first invasion.

Protocol, Part II:

Using an Excel spread sheet, create a line graph that illustrates antibody production from the data in the table below. Time will be the independent variable on the X axis, while the number of antibody units is the dependent variable on the Y axis. You should assume that at time 0 the body was invaded by an unknown antigen. Then you can also assume that the person was exposed for a second time to the same antigen on day 40. You will submit the Excel spreadsheet as an attachment to this assignment as part of your grade for this lab.
Answer the questions that follow.
Table 1.

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Time

Antibody

Units

Time

Antibody

Units

Time

Antibody

Units

Time

Antibody

Units

0

0

16

80

32

0

48

150

4

10

20

24

36

0

52

300

8

70

24

20

40

0

56

260

12

120

28

0

44

40

60

200

*Adapted from The Science of HIV.

Questions:

How does the first part of the graph (days 0-28) compare to the second part of the graph (days 28-60)?

2. Which do you think is the response being made by the memory cells?

State a precise definition of a vaccine and include in your definition the term primary immune response.

Exercise 2: How Vaccinations Work

Protocol:

Examine the following chart and answer question 1below.

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Virus

Disease

Method of Vaccination

Poliovirus

polio

Salk vaccine(inactivated virus)

Sabbin vaccine(weakened virus)

Influenza virus

flu

inactivated virus

Rabies virus

rabies

inactivated virus

Hepatitis B virus

Hepatitis, liver cancer

surface antigen of virus

Rubella virus

German measles

weakened virus

HIV

Aids-related illness

none, yet

*1997, The Science of HIV

Questions:

Although there is no current vaccine for HIV, based on what you now know about vaccines and the immune response, predict the method of vaccination that might be developed in the future. Explain your prediction.

In 2003, a nasal-spray flu vaccine was licensed for use and now gives patients a choice other than the typical flu shot. This nasal-spray vaccine contains three different types of live viruses that are attenuated, cold-adapted, and temperature sensitive. Attenuated means the viruses are weakened and will not cause severe symptoms of influenza. Cold-adapted and temperature sensitive mean the viruses can grow inside the nose and throat, but not in the lungs where the temperature is higher. Based on your knowledge of immunity, how does this vaccine work?