Immunology Medical - NURSING LIJAN

MedicalImmunology

Anas Abu-HumaidanM.D. Ph.D.

Lecture 1

• “These reports urge faculty to refrainfrom presenting science as a sea offacts and work towards ensuring thatstudents have a foundationalunderstanding in biology.”

Resources used for this course

• Lectures will provide a general outlineof main intended learning outcomes,but textbooks are essential for betterunderstanding of the subject.

• Immunity is defined as resistance todisease, specifically infectious disease.The collection of cells, tissues, andmolecules that mediate resistance toinfections is called the immune system,and the coordinated reaction of thesecells and molecules to infectiousmicrobes comprises an immuneresponse.

• Immunology is the study of the immunesystem, including its responses tomicrobial pathogens and damagedtissues and its role in disease.

Immunology introduction

• Immunology is the study of the immunesystem, including its responses tomicrobial pathogens and damagedtissues and its role in disease.

Immunology introduction

Biology of the immune system(e.g. Cells of the immune system,their activation and regulation)

Role of the immune system inhealth and disease. (e.g. Role

in fighting microbes,immunopathologies)

Applications of theimmunology (serology,

immunotherapy)

• Immunology and its applications helpedsave millions of lives, and futurebreakthroughs are expected to savemore!

Immunology introduction

• In Western society, it was not until the lateeighteenth century that a rational approach to theorigin of disease developed.

• In 1798, Edward Jenner, noticed that milkmaidswere protected from smallpox if they had beenfirst infected with cowpox .

Immunology introduction / history

Microbiology introduction / history

Robert Koch 1843 –1910

• Robert Koch was one of the main foundersof modern bacteriology, he identified thespecific causative agents of tuberculosis,cholera, and anthrax and gave experimentalsupport for the concept of infectiousdisease (germ theory), which includedexperiments on humans and other animals

• Pasteur is renowned for his discoveries ofthe principles of vaccination, microbialfermentation and pasteurization, he wasresponsible for disproving the doctrine ofspontaneous generation.

Ibn Sina 980 - 1037

Louis Pasteur 1822 –1895

• Paul Ehrlich and others, recognized that aspecific antigen elicited the production of aspecific antibody . Ehrlich hypothesized thatthese antibodies were specialized molecularstructures with specific receptor sites that fiteach pathogen like a lock and key. Thus, thefirst realization that the body had a specificdefense system was introduced.

• The idea that specific cells could be directlyinvolved with defending the body was firstsuggested in 1884 by Élie Metchnikoff .

• However, it was not until the 1940s that histheories were accepted and the cellmediated, as opposed to the humoral,immune response was recognized

Immunology introduction / history

The Nobel Prize inPhysiology or Medicine1908

• The immune system includes the role of physical, cellular, and chemical systems that arein place and that respond to all aspects of foreignness.

• The immune system targets any “foreign” object, so the first step is to recognize what isself and non- self.

• The second step is to restore homeostasis by eliminating the foreign object.

• The third step is to remember the invading pathogen to respond better the next time itis encountered .

• The immune system is not only active when danger arises, but is constantly sensingdanger and is important for normal physiology and homeostasis similar to thecardiovascular and renal systems.

Immunology introduction

• Mechanisms for discriminating "self" from "non-self"evolved to accomplish the task of fighting pathogens,launching a long history of host-pathogen co-evolution.

• Virtually all organisms have at least one form of defencethat helps repel disease-causing organisms.

• Pathogens evolve new strategies to over come immunemechanisms, and so the host defence becomes morecomplex to defend against invading pathogens.

• Jawed vertebrates have developed higher complexity ofdefence reflected in the adaptive immune response.

Transplantation of parts of sponge to othersponges is met by an immune response

Immunology introduction/ co-evolution

• Antibodies, also calledimmunoglobulins, Y-shapedmolecules are proteins manufacturedby the body that help fight againstforeign substances called antigens.

• Antigens are any substance thatstimulates the immune system toproduce antibodies. Antigens can bebacteria, viruses, or fungi that causeinfection and disease.

• Antigens may also originate fromwithin the body ("self-antigen"), butshould not be attacked by theimmune system in normal situations.

Immunology introduction / What is forgein?

• Host defenses are grouped under innate immunity, which provides immediate protectionagainst microbial invasion, and adaptive immunity, which develops more slowly andprovides more specialized defense against infections

Immunology introduction / INNATE AND ADAPTIVE IMMUNITY

Immunology introduction / INNATE AND ADAPTIVE IMMUNITY

• The immune system duty is to survey thewhole body so it should be presenteverywhere. But there are sites whereimmune cells collect to fulfil theirfunction (e.g. lymph nodes).

• For example, in the small intestine thereis lymphatic tissue that surveys intestinalpathogens called Peyer's patches.

• The bone marrow is an important placefor generation of immune and non-immune blood cells.

Immunology introduction / Location of the immune system

Immunology introduction / cellular components of the immune system

• Immunology is a relatively recent science with applications that extend to othermedical sciences, thus it is important for medical students.

• The immune system in an ancient defence mechanism composed of tissues, cells andmolecules that interact with each other with great complexity.

• Parts of the immune system are continuously active, and help in maintaininghomeostasis.

• Specialized immune cells are mainly in the bone marrow and then circulate the bloodor aggregate in lymph nodes.

• The immune system arms can be divided in general into innate and adaptive.

Immunology introduction / Conclusions

Further reading:

• BASIC IMMUNOLOGY Functions and Disorders of the Immune SystemFIFTH EDITION.Chapter 1. Introduction to the Immune System: Nomenclature, GeneralProperties, and Components