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IMIN 371, Introduction to Immunology Fall Term 2013. Dr. James Stafford CW319-A Biological Sciences Building Phone : (780) 492-9258 Email : stafford@ualberta.ca. The Immune System. http://virus-diseases.blogspot.ca/. Overview of The Immune System. Immune System
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IMIN 371, Introduction to Immunology Fall Term 2013 Dr. James Stafford CW319-A Biological Sciences Building Phone: (780) 492-9258 Email: stafford@ualberta.ca
The Immune System http://virus-diseases.blogspot.ca/
Overview of The Immune System Immune System -Protection from pathogenic invaders. -Pathogens can range from tiny intracellular viruses (~30 nm), to large parasitic worms (100 cm long / 10 mm wide). -Different recognition and destruction mechanisms. -Highly Adaptable and Interconnected System. Immune System Components -Various Molecules, Cells, Pathways, and Organs. -Tightly interconnected system. -Involves specialized microenvironments (i.e. immune organs/tissues). Different Branches of the Immune System -INNATE (Cellular and Humoral components) -ADAPTIVE (Cellular and Humoral components)
Two major branches of the Immune System Chapter 18 Immune Dysfunction in Autism Spectrum Disorder By Jonna B. Westover, Thayne L. Sweeten, Michael Benson, Patricia Bray-Ward and Anthony R. Torres DOI: 10.5772/22318
Historical Perspective of Immunology IMMUNITY -individuals who recover from certain infectious diseases are thereafter protected from the disease. -Immunis meaning “Exempt”; state of protection from disease. http://www.ebinrushed.com/history/7.php
Vaccination Studies and Immunology -Attempts to deliberately induce immunity lead to the emergence of the field of immunology. -VARIOLATION: Smallpox (Viriola major virus) Fatal in 30% of infections
Edward Jenner (1798) -Milkmaids that contracted cowpox were immune to the more severe smallpox disease. -Inoculation; introducing fluid from a cowpox pustule into people for protection from smallpox. Louis Pasteur -Induction of immunity to the bacterium VibrioCholerae. -Important concepts of; ATTENUATED: VACCINE: VACCINATION: http://www.ebinrushed.com/history/7.php
Examples of Attenuation From the following article, Viral attenuation by design. Harriet L Robinson Nature Biotechnology 26, 1000 - 1001 (2008) doi:10.1038/nbt0908-1000
Vaccination and Human Health Vaccine Challenges today: HIV, Malaria, Influenza
Immunity involves both Humoral and Cellular components Pasteur showed that vaccines work; but he did not understand how (processes and mechanisms??) Emil von Behring and Shibasaburo Kitasato (1890) -first insights into the mechanisms of immunity. -serum could transfer immunity to diptheria. Elie Metchnikoff (1883) -demonstrated that certain white blood cells, which he termed phagocytes, ingested (phagocytosed) microorganisms and other foreign material. ..Cells vs. Soluble agents in immunity. ….thus began the concepts of Cellular and Humoral Immunity. Immunization vs. Rabies
CELLULAR Immunity (1882; Elie Metchnikoff) (rose thorn inserted into starfish larvae)
HUMORAL and CELLULAR components of IMMUNITY Chapter 18 Immune Dysfunction in Autism Spectrum Disorder By Jonna B. Westover, Thayne L. Sweeten, Michael Benson, Patricia Bray-Ward and Anthony R. Torres DOI: 10.5772/22318
HUMORAL IMMUNITY SERUM -The liquid, noncellular component recovered from coagulated blood. -These soluble components could transfer immunity. -What are the active components in blood serum? -Neutralize toxins Antitoxin -Precipitate toxins Precipitin -Agglutinate (clump) bacteria Agglutinin Elvin Kabat (1930s) -A fraction of serum, Immunoglobulin, was responsible for all these activities. -These soluble serum proteins are now referred to as antibodies. -Discovery of these immune proteins led to their use in clinical practices. ANTISERUM: PASSIVE IMMUNITY: ACTIVE IMMUNITY:
Immunoglobulins / Antibodies bind Antigens http://www.daviddarling.info/encyclopedia/I/immunoglobulin.html
CELLULAR IMMUNITY IMMUNITY also mediated by specific CELLS and their responses -Immunity to some pathogens (but not all) can be conferred by transferring WBC’s between animals. -Merrill Chase (1940s) conferred immunity against Tuberculosis in guinea pigs. -LYMPHOCYTES identified as the major WBC’s responsible for cellular immunity. -Bruce Glick (MS State University) discovered; T Lymphocytes (T cells); cells derived from the Thymus -mature in the thymus. -express the T cell receptor (TCR) and CD4 or CD8. -participate in cellular immunity. -fight off intracellular pathogens. B Lymphocytes (B cells); cells derived from bursa of Fabricius in birds -develop in the Bone marrow in mammals. -express membrane-bound antibodies; called the B cell receptor (BCR). -activated B cells produce/secrete antibodies. -fight off extracellular pathogens.
Bursa of Fabricius http://partnersah.vet.cornell.edu/avian-atlas/search/lesion/375 http://www.onlineveterinaryanatomy.net/sites/default/files/original_media/image/asset_9202_45%20-%20bursa%20labelled%20avian.jpg http://askabiologist.asu.edu/b-cell
Following Slides deal with THREE important Concepts for Understanding the Mammalian Immune Response http://theibdimmunologist.com/learning/basic-immunology
1. Invading pathogens are diverse and must breach natural barriers prior to infection PATHOGENS -Any organism that causes disease. -Human pathogens are grouped into four major categories (Table 1-3). -Common characteristics attributed to groups of pathogens (but not the host), can be exploited by the immune system for pathogen recognition/destruction. -Immune system is not engaged until pathogen breaches physical barriers of the body such as; -Skin (epithelial layer) -Mucous Membranes (digestive, respiratory, urogenital tracts) -pH of secretions (stomach, tears, sweat, saliva) -When these barriers are breached, you get infected. -Animal bites; malaria (mosquitos), plaque (fleas), Lyme disease (ticks). -Burns; if lose the protective barrier skin are highly susceptible to disease. -Cuts; introduction of pathogens beneath epithelial layer.
2. The Immune Response Quickly Becomes Tailored to Suit the Specific Assault -Effective immune defenses are specific to the PATHOGEN that has breached the physical barriers of the host. -Activation of appropriate cells and molecules (anti-bacterial vs. anti-viral). -Influenced by; -Chemical structures present on pathogens (signatures; what is it?). -Location of the pathogen (inside or outside of cells; where is it?) -Location of the immune response (blood, tissues, lymph N., spleen). -Need pathogen RECOGNITION to initiate Effective immune responses. -HUMORAL Response (Extracellular Pathogens) -CELLULAR Response (Intracellular Pathogens)
http://medicinembbs.blogspot.ca/2011/03/process-of-immunity-images.htmlhttp://medicinembbs.blogspot.ca/2011/03/process-of-immunity-images.html
3. Innate Pathogen Recognition Molecules are Encoded in the Germline and allow for Pathogen ‘Profiling’ -Most pathogens express unique structures not found in mammals. -Pathogen Associated Molecular Patterns (PAMPs) -Pattern Recognition Receptors (PRRs) -PRRs are proteins encoded in the genome and expressed by many different cells. -Allow for rapid detection/profiling of the most common pathogens. -This early categorization of pathogens facilitates tailoring of the subsequent response to suit the assault. -Initiation of HUMORAL vs. CELLULAR responses.
Pathogen Recognition Molecules Can Be Encoded in the Germline or Randomly Generated Recognition of PAMPs from different classes of microbial pathogens. Mogensen T H Clin. Microbiol. Rev. 2009;22:240-273
Innate Acquired or Adaptive HumoralCell Mediated CD4+ CD8+ TH1 TH2
http://nfs.unipv.it/nfs/minf/dispense/immunology/lectures/files/evolution_immunity.htmlhttp://nfs.unipv.it/nfs/minf/dispense/immunology/lectures/files/evolution_immunity.html
http://medicinembbs.blogspot.ca/2011/03/process-of-immunity-images.htmlhttp://medicinembbs.blogspot.ca/2011/03/process-of-immunity-images.html
Differences in the primary and secondary response to injected antigen reflect the phenomenon of immunological memory
Clonal Selection (B cells; also applies for T cells) http://classes.midlandstech.edu/carterp/Courses/bio225/chap17/ss3.htm
The Antibody Responses IgG produced IgM produced