The Immune System: Nature's Silent Army


Note:  This is an updated SDG originally given in 2015 coordinated by Marilyn Slater and Bob Moore-Stewart. 

The immune system stands between us and a world of attackers who would otherwise kill us in short order.  What is it? – and how does it do its job?  All multicellular organisms such as sponges (Porifera) exhibit immune responses and mechanisms for discriminating self from non-self.  A long history of host-pathogen co-evolution (from sponges to humans) has brought about a variety of diseases and immune strategies. 

This SDG will focus on immunity in vertebrates with emphasis on mammals and the human immune response to disease. The selected core book by Lauren Sompayrac (5th edition, 2016) provides an excellent introduction for the non-scientist and non-professional healthcare professional PLATO member.

 How do immune cells distinguish between self and non-self?  Complexity and effectiveness are hallmarks of the immune system.  It is able to identify and dispatch most pathogens and yet spare our own tissues. It exhibits both innate and adaptive immunity, allowing immune cells to respond immediately to foreign invaders and then follow up the defense with fine-tuned warriors who search out specific pathogens in order to kill and devour them.  The fine-tuning is regulated by a complex series of chemical signals.  The detailed mechanisms of the immune response are only now becoming understood through state-of-the-art techniques in biochemistry and molecular biology. 

Diseases have many causes -- viruses, bacteria, parasites, fungi, mutations, allergens – to name some of the most common.  We will study the way in which the immune system provides surveillance and fights back in various diseases. Vaccines offer a way to train the immune system to fight disease more effectively.  In some cases, the immune system has harmful, even fatal, effects.  In autoimmune diseases, such as lupus and multiple sclerosis, immune cells attack the body that gave rise to them.  The greatest challenge to organ transplantation is attacks by the recipient’s immune system. We will explore emerging revelations about cancer immunotherapy, the human genome and microbiome, progress in AIDS therapy, and autoimmune treatments that impact millions of lives.

This SDG will enlighten and enable an enhanced understanding of the extraordinary immune system as "an elegant defense."

Weekly Topics

1)         Overview and evolution of the immune system

2)         The innate Immune system – the first line of immunological defense

3)         Adaptive immunity -- B cells & antibody production

4)         The magic of antigen presentation and T cells

5)          Secondary lymphoid organs and lymphocyte trafficking

6)           Restraining the immune system

5)         Tolerance induction and MHC restriction– mechanisms of self vs. non-self recognition

7)         Immunological memory

8)         Vaccination – preventative and therapeutic; memory in immune cells

9)         Organ transplants – overcoming rejection by the immune system

10)         Inborn errors in the immune system, e.g. SCID (The Boy in a Bubble); Autoimmune disorders (lupus, multiple sclerosis, rheumatoid arthritis                       

11)         Tumor immunology -- cancer and the immune system

12)      HIV and AIDS - - -example of immunodeficiency

13)      Allergies, hypersensitivity, anaphylactic shock

14)      Malaria, Ebola, Mycobacterial diseases (leprosy and tuberculosis) – challenges continue


Core Book

Sompayrac, Lauren.  How the Immune System Works,5th Ed.  John Wiley & Son, 2016.

Suggested Reading

Richtel, Matt. An Elegant Defense: The Extraordinary New Science of The Immune System (A Tale in Four Lives), HarperCollins, 2019 

General Web Sites with Immunology Articles:  The New York Times science section National Institute for Allergy and Infectious diseases  Full text books online in medicine and biology  Discover magazine online – many full text articles

Immunology Articles & Web Sites

Casanova, Jean-Laurent; Abel, Laurent.  "Inborn errors of immunity to infection: the rule rather than the exception.   J. Exp Med 2005 Jul 18;202(2):197-201

There are remarkably good websites on all aspects of immunology, from sponge to PLATO member, including excellent Ted Talks and lectures by leading immunologists.