Topic 1- Introduction to Immunology (Historical background, Innate Immunity) PDF

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Page | 1I.) Introduction to Immunology(Historical background, InnateImmunity)ImmunologyIt is a study of host’s REACTION to foreign substances and RESISTANCE to diseases and infections CELLS, TISSUES, MOLECULES that mediate resistance to infections MEDICALLY related consequences when the immune syste...

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CLINICAL IMMUNOLOGY AND SEROLOGY Introduction to Immunology (Historical background, Innate Immunity)

I.)

Immunology It is a study of host’s REACTION to foreign substances and RESISTANCE to diseases and infections CELLS, TISSUES, MOLECULES that mediate resistance to infections MEDICALLY related consequences when the immune system: o FAILS to respond or, o RESPONDS in an EXAGGERATED form Immunity According to Taliaferro “The host is an island invaded by strangers with different needs, different food requirements, and different localities in which to raise their progeny” Derived from the Latin Word, ‘Immunis” which originally means, exemption from military service, tax payments The state of being resistant to infection Primary role – surveillance and destruction of substances that are foreign to the body o 1. Protection

2. Vast number of biological mechanisms used by the body o 3. Ability to resist foreign organisms plus their products o 4. Ability of the immune system to launch defense mechanism Divided in two (2) categories o INNATE Immunity  ability of an individual to resist infections by means of normally present body functions.  Present at birth o ADAPTIVE Immunity  type of resistance that is characterized by specificity for each individual pathogen or microbial gent  Involves both humoral and cellular immunity o

Type of Immunity Innate Immunity 1. Mechanisms involved are non-specific 2. Mechanisms that preexist the invasion of foreign agents 3. Components are preformed

Adaptive Immunity 1. Reinforcement 2. Inducibility 3. Specificity 4. Diversity 5. Memory 6. Specialization 7. Self-limitation

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4. They are non-adaptive, 8. Discrimination has a standardized magnitude of response 5. Lacks immunologic memory

Barrier

Innate Skin

Soluble Complement Protein Cells Phagocytes Mediators IL-1, TNF Immune System

Adaptive Mucosal Immunity Antibodies T and B cells y- interferon

Recognizes invading pathogens or foreign substances and defends the body by producing an immune response. In many species, can be classified into sub-systems: innate (non-specific) and adaptive (specific). How does the immune system recognize a pathogen? Invading pathogens have antigens (Ag) on their surface, which the immune system recognizes as nonself. Ag can be a cell surface protein, glycoprotein, liposaccharide, lipids. Non-specific innate immune cell receptors bind Ag directly.

CLINICAL IMMUNOLOGY AND SEROLOGY The presence of Ag causes immune response to be activated to destroy pathogen Components of Immune System Non specific Specific Enzymes (lysosomes) Organ ( Spleen, Mucous Lymph node, Cilia Thymus, etc.) Keratin layer of skin Cells ( Lymphocyte Macrophages (WBCs, monocyte, etc. Immunocytes cells found in the immune system. Ex. Lymphocytes, monocytes Lymphoid Organs structures or sites where lymph production, maturation or differentiation occurs. Immune Response refers to all interactions of the components of the immune system in response to antigens. Desirable effects of immune response II.) III.)

Immunity Recovery from diseases

Undesirable effects of immune response I.) Immunodeficiency II.) Allergic/Hypersensitivity reactions III.) Autoimmune Disorders IV.) Cell Lysis Properties of Immune Response I.) Recognition of self vs. non-self II.) Mediated by Lymphocytes III.) Acquired IV.) Specific V.) Transferable VI.) Memory Response Lymphokines released by activated lymphocytes, have the ability to affect activity of the other cells Monokines released by activated monocytes Sensitized cells already involved in immune response or a cell is exposed to antigen Antigen/Immunogen These are foreign substances/material that can induce an immune response It can be harmful/harmless

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Example of Antigens I.) Microbial antigens – harmful Ag II.) Cellular antigens harmless in III.) Autoantigens – immunocompetent individuals IV.) Major Histocompatibility Complex – important in organ transplantation Antibody serum factors in the blood formed in response to foreign substances, also known as immunoglobulin Serology Refers to the analytical procedures performed in the laboratory using blood samples particularly serum to look into the components of the immune response It focuses on: o Identifying antibodies o Identifying antigens o Investigate problems with the immune system o Determine organ, tissue, or fluid (blood) compatibility In vitro antigen-antibody reactions Study of antigen-antibody reactions that can be utilized in vitro

CLINICAL IMMUNOLOGY AND SEROLOGY I.1.) History Immunology

and

Milestone

in

Thucidydes (430 BC) A Greek Historian and General Believed to have written the first description of immunity when plague hit Athens "the sick and the dying were tended by the pitying care of those who had recovered, because they knew the course of the disease and were themselves free from apprehensions . For no one was ever attacked a second time, or not with a fatal result" Smallpox

Variolation Pioneered by the Chinese in the 10th Century Considered as an earliest attempt to induce immunity Healthy people were exposed from a material obtained from the smallpox lesion by inoculating it under the skin or inserting powdered scabs from smallpox pustules into the nose Goal – to induce a mild, but protective infection Downsideinoculum is not standardized, it often resulted to disfigurement or death from smallpox infection The practice was brought to Europe through the effort of Lady Mary Wortley Montague Series of experiments were conducted among condemned prisoners to establish the safety of the procedure It was widely accepted in Europe and the American continent

caused by Variola major & Variola minor Last naturally occurring case occurred in October 1977 The Greek historian Thucydides observed that those who survived the previous smallpox plague did not become re-infected with the disease Thus, the concept of immunity was VACCINATION: First safe vaccine for created by observing that smallpox individuals previously infected were protected from subsequent infection Benjamin Jetsy This led to variolation, the exposure An English farmer notable for his early to material derived from smallpox experiment in inducing immunity pustules. Individuals can still transmit against smallpox using cowpox in smallpox after variolation Page | 3 RIGIDOR S. PADAYHAG | MLS 3D |UNIVERSITY OF THE IMMACULATE CONCEPTION

1774. He inoculated his wife with lesion from cowpox caused by Vaccinia virus Edward Jenner (1749-1823) An English Physician, inoculated James Phipps, an 8 year old boy with a material from cowpox lesion obtained from the hand of a milkmaid o James developed mild infection of cowpox o Weeks after he recovered, he was injected by Jenner with lesion from smallpox – No disease developed WHO certified the eradication of the smallpox in 1980 Paved the way for a scientific breakthrough in immunology which is: VACCINATION Cross Immunity o was also demonstrated in his experiment SCI-BIT! The term vaccine was coined by Louis Pasteur in honor of Jenner ATTENUATION: Attenuation of Vaccine Attenuation The extract used for variolation was containing active smallpox pathogen but this was too risky but

CLINICAL IMMUNOLOGY AND SEROLOGY the pathogen in the extract was made in active by culturing the cells at 45 degrees Celsius ( 35 degreesnormal temperature) – in cases of sheep inoculated with attenuated Anthrax Another method of attenuation was passing the microorganism in an unusual host Louis Pasteur A French Biologist and the “Father of Immunology” discovered attenuation or “weakening” of virulence factors of microorganisms used for vaccination Performed experiments using: o Chicken cholera (first discovered through an unintended laboratory incidentt!) o Rabies – using infected dogs spinal cord

Demonstrated the process by inserting small splinters into starfish larvae, then found unusual cells surrounding the splinters

OTHER SIGNIFICANT MILESTONE

HUMORAL THEORY OF IMMUNITY Emil Adolph Shibasaburo

von

Behring

&

Kitasato

Showed that injections of serum from an animal with tetanus could confer immunity of the disease to the recipient animal Demonstrated transfer of immunity of diphtheria by a soluble anti-toxin present in the blood of infected persons ANTIBODY FORMATION THEORY Paul Ehrlich German Physician, predicted the existence of antibodies OPSONIZATION

CELLULAR THEORY OF IMMUNITY Through Phagocytosis

Elie Metchnikoff (1883-1905) A Russian Zoologist, the Father of Natural Immunity, discovered phagocytosis

recognized antigen are coated by an antibody and/or complement to trigger phagocytosis Almroth Wright (together with Stephen Douglas, Joseph Denys) British bacteriologist and immunologist, observed that opsonins coat bacteria so that they

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become susceptible to ingestion by phagocytic cells discovered opsonins and described its relation to phagocytosis

Year Scientist/s Research 1901 Emil von Antitoxins Behring Serum 1905 Robert Koch Cellular Immunity in TB 1908 Ellie Metchnikoff 1908 Paul Ehrlich 1913 Charles Richet 1919 Jules Bordet 1930 Karl Landsteiner 1960 Macfarlane Burnet, Peter Medawar 1972 Gerald Edelman, Rodney Porter 1977 Rosalyn Yallow 1980 George Snell , Jean Dausset Baruj Benacera

Phagocytosis Immunity Anaphylaxis Complement Human Blood Group Ags Immunologic Tolerance Structure Antibodies

of

Radioimmunoassay Major Histocompatibility Complex

CLINICAL IMMUNOLOGY AND SEROLOGY 1984 Niels Jerne .Georges Koehler Cesar Milstein 1987 Susumu Tonegawa 1991 E. Donnall Thomas, Joseph Murray 1996 Peter Doherty, Rolf Zinkermagel 1903 Almroth Wright

Immunoregulation Monoclonal Antibody

Antibody Diversity Transplantation

Cytotoxic T cellRecognition of virally infected cells Theory of Cellular and Humoral Immunity

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