MCB 229 Spring 2000 Study Guide 23 Prof. Terry

Covers Lecture for May 4

This study guide is intended for you to use while you are doing the assigned text reading. Quiz questions will be made with reference to topics in this study guide.

NOTE: There will be no Quiz #23 – some questions on this material may be included in Quiz 24, which will cover the last lecture of the course.

Chapter 31: Immune response: B- and T-cell biology. Note: in general, this chapter contains much more detail than is needed for a microbiology course. Concentrate on the following questions.

What are: cytokines, lymphokines, interleukins, colony-stimulating factors? How are cytokines different from hormones? How are they similar?
To what class of receptor moleules do cytokines bind?
What are some of the cellular responses activated by cytokine binding? (see Fig. 31.3 and text)
Figure 31.2 summarizes a lot of information on the variety of cytokines secreted by different white blood cells, most of which we can safely ignore at present. But do look at the cytokines secreted by T-helper cells to note the astonishing complexity of control that such cells exert.
B-cells contain antibody-like molecules attached to their cell membranes, called B-cell antigen receptors (BCRs). How many BCRs are found on one B-cell? How many different antigens can these BCRs recognize?
What are the steps that activate a B-cell? Is it necessary that antigen binds to a B-cell? Is this sufficient? Study Fig. 31.4, which describes a typical sequence of stages of activation, involving (a) a macrophage (antigen-presenting cell), (b) a T-helper cell, and (c) a B-cell. Read the text on p. 633 (right column) carefully to accompany Fig. 31.4.
Are there any antigens which can stimulate antibody production without T-cell involvement? If so, what are some examples?
T-cells carry T-cell antigen receptors (TCRs) on their cell surface. These are not antibodies, but they have certain antibody-like properties; variable and constant regions, specific binding to antigen. TCRs must recognize antigen in order to produce cytokines necessary for stimulating B-cells.
What are MHC molecules? How do class I and class II MHCs differ?
What role do each of the following cell types play? T-helper cells, T-suppressor cells, cytotoxic T cells, natural killer cells.
What is a superantigen? What are some pathogens that secrete superantigens? What effect do they have on their hosts?
What is an autoimmune disease? How do microbial infections affect these diseases?
Skim sections on the following topics: hypersensitivities, transplant rejections, immunodeficiencies, human blood types, cell-associated differentiation antigens. I will not test you on this material.