Howard Hughes Medical Institute Holiday Lecture Series - The Immune System - Friend And Foe - Lecture Three - How the Host Avoids 'Friendly Fire' by John W. Kappler, Ph.D. Lecture 3 of 4.
John W. Kappler, Ph.D., HHMI Investigator, National Jewish Medical and Research Center
Philippa Marrack, Ph.D., HHMI Investigator, National Jewish Medical and Research Center
The immune system is usally a very good friend - protecting the body from disease. Sometimes, however, it is exploited by an invader that attacks the body. How does the immune system defend itself so successfully against a constant onslaught of bacteria and viruses? How do some invaders occasionally trick the immune system?
In four lectures, two noted scientists who have advanced our understanding of the immune system explore its secrets. John W. Kappler, Ph.D., and Philippa Marrack, Ph.D., explain how receptors on two kinds of lymphocytes - B cells and T cells - recognize invading organisms in fundamentally different ways. Normally these cells do not attack thier host, but some lymphocytes escape screening to cause serious autoimmune diseases such as juvenile diabetes and rheumatoid arthritis. The scientists also discuss the novel ways that some infectious agents have evolved to circumvent the immune system.
Demonstrations and questions from a student audience enhance the lectures.