introduction to immunology, science of immunity
DESCRIPTION
Introduction to immunology, Science of ImmunityTRANSCRIPT
![Page 1: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/1.jpg)
Introduction to ImmunologyScience of Immunity
How we are ProtectedDr.T.V.Rao MD
1Dr.T.V.Rao MD
![Page 2: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/2.jpg)
Immunology• Immunology is the study of our
protection from foreign macromolecules or invading organisms and our responses to them.
• Host – e.g. me!!!!• Foreign macromolecule, antigen –
e.g. virus protein, worm, parasite (Everything that should not be in my body) 2Dr.T.V.Rao MD
![Page 3: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/3.jpg)
3Dr.T.V.Rao MD
![Page 4: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/4.jpg)
Dr.T.V.Rao MD 4
![Page 5: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/5.jpg)
Immunology
• Contains Basic science• Clinical Application Host defense reactions to foreign
Antigen Substance is not self Antigen recognizing Cell Mediated Host defense functions
5Dr.T.V.Rao MD
![Page 6: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/6.jpg)
Definitions• Immune system = cells, tissues, and
molecules that mediate resistance to infections
• Immunology = study of structure and function of the immune system
• Immunity = resistance of a host to pathogens and their toxic effects
• Immune response = collective and coordinated response to the introduction of foreign substances in an individual mediated by the cells and molecules of the immune system 6Dr.T.V.Rao MD
![Page 7: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/7.jpg)
Role of the immune system
• Defense against microbes• Defense against the growth of tumor
cells–kills the growth of tumor cells
• Homeostasis–destruction of abnormal or dead cells
(e.g. dead red or white blood cells, antigen-antibody complex)
![Page 8: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/8.jpg)
Jenner - Smallpox vaccine
• Noticed that milkmaids that had contracted cowpox did NOT get smallpox
• Test on an 8 year old boy, injected cowpox into him (NOT very nice……)
• Follwed by exposure to smallpox• Vaccine was invented (latin vacca
means ”cow”)
8Dr.T.V.Rao MD
![Page 9: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/9.jpg)
First insights into mechanics of immunity…
1880’s- Metchnikoff discovered phagocytic cells that ingest microbes and particles
cells conferred immunity
1890- von Behring and Kitasato discovered blood sera could transfer immunity
liquid of blood conferred immunity
Q: Which confers immunity… cells or serum?
Emil von Behring
S. Kitasato
Elie Metchnikoff9Dr.T.V.Rao MD
![Page 10: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/10.jpg)
Louis Pasteur watching as Joseph Meister receives attenuated rabies vaccine (1885)
10Dr.T.V.Rao MD
![Page 11: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/11.jpg)
Subjects In Immunology
• Cell mediated host defense functions• Antibody related defense mechanisms• Hypersensitivity reactions ( Including
Allergy )• Auto Immunity• Immunodeficiency• Transplantation
11Dr.T.V.Rao MD
![Page 12: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/12.jpg)
• Protect against pathogens
• Eliminate damaged or malignant cells
12Dr.T.V.Rao MD
![Page 13: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/13.jpg)
What is Response to Infection
• Immunity can be Innate ( Nonadapative )
• Adaptive - Acquired.
Dr.T.V.Rao MD 13
![Page 14: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/14.jpg)
Immunology is a ComplexSubject
14Dr.T.V.Rao MD
![Page 15: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/15.jpg)
Two types of immunity 1. Innate (non-adaptive)
– first line of immune response– relies on mechanisms that exist before
infection
2. Acquired (adaptive)– Second line of response (if innate fails)– relies on mechanisms that adapt after
infection – handled by T- and B- lymphocytes– one cell determines one antigenic determinant 15Dr.T.V.Rao MD
![Page 16: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/16.jpg)
Distinction Between Innate and Adaptive Immune Responses
• Innate immunity is non-adaptive and helps to initiate adaptive immune responses (= first line of defense – but LIMITED)– Immediate (0-4 hours)
• Adaptive immunity provides a more universal line of defense and has long-lived memory to provide protection upon re-infection– Second line of defense– Generation of Ag-specific effector cells– Early (4-96 hours)– Late (>96 hours) 16Dr.T.V.Rao MD
![Page 17: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/17.jpg)
THE EVOLUTION OF IMMUNITY
17
Immunity
Innate immunity Acquired immunity
Non-specific SpecificImmediate onset Delay onset
Humoral Immune Response
Cellular Immune Response
Antibodies production T-cell activationDr.T.V.Rao MD
![Page 18: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/18.jpg)
Basic classification of Immunity
Designed by Dr.T.V.Rao MD 18
![Page 19: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/19.jpg)
Different types of Immunity
A - Non specific 1 Species 2 Racial 3 Individual
B Specific 1.Species 2 Racial 3 Individual
19Dr.T.V.Rao MD
![Page 20: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/20.jpg)
The immune system
20
Immune system
• Anatomic barriers (Skin, mucous membranes)
• Physiological barriers (temperature, pH)
• Phagocytic Barriers (cells that eat invaders)
• Inflammatory barriers (redness, swelling, heat and pain)
• Antigen specificity • Diversity • Immunological memory • Self/nonself recognition
Innate (non-specific) immunityAdaptive (specific) immunity
Dr.T.V.Rao MD
![Page 21: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/21.jpg)
Innate, Surface Defenses• Skin
– physical barrier to microbes– Keratin resistant to most bacterial enzymes & toxins– secretions are acidic pH 3-5
• Mucosa – physical barrier & produces a variety of protective
chemicals• Gastric mucosa
– very acidic & produces proteolytic enzymes• Saliva & lacrimal fluid contain lysozyme• Mucous
– traps bacteria & moves them away from epithelial surface
![Page 22: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/22.jpg)
22Dr.T.V.Rao MD
![Page 23: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/23.jpg)
Different types of Immunity
A - Non specific 1 Species 2 Racial 3 Individual
B Specific 1.Species 2 Racial 3 Individual
23Dr.T.V.Rao MD
![Page 24: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/24.jpg)
Types of Immunity
Acquired Immunity A Active Natural Artificial B Passive Natural Artificial
24Dr.T.V.Rao MD
![Page 25: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/25.jpg)
Resistance to Infectious Disease
• Innate immunity (nonspecific resistance) protects us against all pathogens: “over-the-counter defenses”
• Adaptive immunity (specific resistance) is defenses against specific pathogens: “prescription defenses”
![Page 26: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/26.jpg)
Innate Immunity
Innate Immunity is resistance that is preexisting and is not acquired through contact with a foreign substance known as antigen
Individual has innate Immunity by genetic or constitutional Make Up
Non related to prior contact with Microorganisms or Immunization
26Dr.T.V.Rao MD
![Page 27: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/27.jpg)
Physical and Chemical Barriers
• Skin, mucus membranes• Cilia, mucus, reflexes• pH, lysozyme, fatty
acids, defensins• Normal flora• Genetic resistance
– species differences– individual differences
![Page 28: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/28.jpg)
It is Dependent on
• Species• Race
( Racial )• Individual
Dr.T.V.Rao MD 28
![Page 29: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/29.jpg)
Species and Immunity
• Immunity refers to total resistance to a Pathogen by all members of the species
• Eg Human do not get plant diseases Humans do not get some animal diseases• Dependent on Human configuration
physiology ? Biochemical difference29Dr.T.V.Rao MD
![Page 30: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/30.jpg)
Race - Immunity
• Genetic resistance Plasmodium falciparum malaria resistance in Africa
• In sickle cell anemia immune to malaria
30Dr.T.V.Rao MD
![Page 31: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/31.jpg)
Individual - Immunity
• Twins homozygous twins exhibit similar resistance
• Susceptibility similar in Leprosy
• Tuberculosis similar resistance
31Dr.T.V.Rao MD
![Page 32: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/32.jpg)
Factors Influencing Innate Immunity
• Placenta prevent infection
• But still can infected with Toxoplasmosis, Rubella, CMV and Herpes infection.
• Can produce congenital malformations
32Dr.T.V.Rao MD
![Page 33: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/33.jpg)
Immunity In Adults
• Polio infection , and Chickenpox highly severe in adults.
• Enlargement of prostate lead to UTI
Dr.T.V.Rao MD 33
![Page 34: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/34.jpg)
Hormonal Influence on Immunity
• Diabetes mellitus• Hypothyroidism in
adults• Adrenal
dysfunction• Stress increases
steroids predisposes to Infection
Dr.T.V.Rao MD 34
![Page 35: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/35.jpg)
Nutrition
•Some protection in some diseases
Dr.T.V.Rao MD 35
![Page 36: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/36.jpg)
Mechanism's of Immunity
• Epithelial surfaces
Skin and Epithelial surfaces cover the body and protects the individuals
Healthy skin poses bactericidal influence, salt, drying sweat , Long fatty acids
Wet hand predisposes to Mycotic and pyogenic infections
36Dr.T.V.Rao MD
![Page 37: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/37.jpg)
Mucous Membranes
•Respiratory tract Shape of Nose, Nasal orifice 37Dr.T.V.Rao MD
![Page 38: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/38.jpg)
Mechanism's of Immunity• Epithelial surfaces Skin and Epithelial surfaces cover
the body and protects the individuals
Healthy skin poses bactericidal influence, salt, drying sweat , Long fatty acids
Wet hand predisposes to Mycotic and pyogenic infections 38Dr.T.V.Rao MD
![Page 39: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/39.jpg)
• Cilia in Respiratory tract
• Propel the foreign particles
• Respiratory secretion contain 39Dr.T
.V.Rao MD
![Page 40: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/40.jpg)
Oral Cavity• Saliva• Stomach HCl• Large
intestine large number of bacteria
40Dr.T.V.Rao MD
![Page 41: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/41.jpg)
Conjunctiva• Contain lachrymal
secretions• Tears contains
antibacterial substances
• Lysozyme present except in CSF, Sweat, Urine
41Dr.T.V.Rao MD
![Page 42: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/42.jpg)
Other Mechanisms
• Flushing action of urination drives out Microbes in the Urethra
• Spermine in Semen
Dr.T.V.Rao MD 42
![Page 43: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/43.jpg)
Innate, Internal Defenses
• Phagocytes– Macrophages: derived from monocytes
• Free Macrophages: roam through tissues• Fixed Macrophages: Kupffer cells (liver) &
microglia (brain) • Ingest cellular debris, foreign material, bacteria,
fungi
– Neutrophils: ingest pathogens– Eosinophils: weakly phagocytic of pathogens.
Attack parasites (degranulation)– Mast Cells: phagocytic of various bacteria
![Page 44: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/44.jpg)
Antibacterial Substances
• May be present Blood as Complement
• Antibacterial substances in Blood
Betalysin,
Leukin
Lactoperoxidase in Milk
Dr.T.V.Rao MD 44
![Page 45: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/45.jpg)
Interferon's in Immunity• Interferon's (IFNs) are natural proteins
produced by the cells of the immune system of most vertebrates in response to challenges by foreign agents such as viruses, parasites and tumour cells. Interferon's belong to the large class of glycoproteins known as cytokines
• Interferon's are more useful than Antibodies
45Dr.T.V.Rao MD
![Page 46: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/46.jpg)
Microbial AntagonistsNormal flora Help us
• Normal Microbial flora
46Dr.T.V.Rao MD
![Page 47: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/47.jpg)
Normal flora Helps Us• We harbour near 1014 bacteria. This group
of organisms, traditionally referred to as "normal flora" (although they are not plants) is composed of a fairly stable set of genera, mostly anaerobes. While each person has a relatively unique set of normal flora, members of the Streptococcus and Bacteroides make up a large percentage of the inhabitants. These organisms contribute to our existence in several ways’ 47Dr.T.V.Rao MD
![Page 48: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/48.jpg)
Other Normal Flora
• Streptococcus and Bacteroides make up a large percentage of the inhabitants. These organisms contribute to our existence in several ways’
• Help us by competing with pathogens such as Salmonella
• Help us by providing vitamins or eliminating toxins (e.g. Bacteroides)
• Harm us by promoting disease (e.g. dental caries) • Cause neither help nor harm (e.g. "commensals").
Dr.T.V.Rao MD 48
![Page 49: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/49.jpg)
Normal Bacterial Flora of Conjunctiva
49Dr.T.V.Rao MD
![Page 50: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/50.jpg)
Cellular Factors in Innate Immunity
• Metchnikoff 1883• Cells called as Phagocytic cells Microphages, MacrophagesMicrophages Polymorph nuclear neutrophilsMacrophages Histiocytes wandering Amoeboid
cellsMonocytes in BloodCells in Reticuloendothelial System These cells remove foreign particles
50Dr.T.V.Rao MD
![Page 51: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/51.jpg)
Phagocytes• Phagocytes = eating cells
–Neutrophils (PMNs) are present in the highest numbers in blood
–Macrophages (“big eaters”) in the tissues encounter the pathogen first•Secrete cytokines ---> inflammation, systemic responses
![Page 52: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/52.jpg)
How Phagocytes act• Phagocytic cells
reach the site o Inflammation
• Attracted by Chemo tactic substances
• Ingest particle material
52Dr.T.V.Rao MD
![Page 53: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/53.jpg)
Cellular and Inflammatory Components of Innate Immunity
• Cellular–Phagocytic
cells• Inflammatory
–Vasodilation–Capillary
permeability53Dr.T.V.Rao MD
![Page 54: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/54.jpg)
54Dr.T.V.Rao MD
![Page 55: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/55.jpg)
Phagocytosis
![Page 56: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/56.jpg)
Capsule In Innate immunity
• Some bacteria have capsules
• Streptococcus pneumonia
• Klebsiella pneumonia• Bacteria with capsules
are not ingested by Phagocytes unless in the presence of opsonins
• Bacteria are fixed against fixed surface such as alveoli
56Dr.T.V.Rao MD
![Page 57: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/57.jpg)
Mechanism of Phagocytosis
• Bacteria are phagocycosed into vacuole (Phagosome)
• Forms phagolysosome
• Lytic enzymes destroy the Bacteria
• Brucella and Leprosy
57Dr.T.V.Rao MD
![Page 58: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/58.jpg)
Natural Killer cellsNK cells
58Dr.T.V.Rao MD
![Page 59: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/59.jpg)
Mediators of inflammationVasodilation, smooth muscle contractionIncreased vascular permeabilityEdema, extravasation
(histamines, prostaglandins, kinins)ExtravasationChemo taxis
(cytokines, chemokine's, complement)Systemic response- fever, acute-phase proteins
C-reactive protein
![Page 60: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/60.jpg)
Interferon and Function
![Page 61: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/61.jpg)
Anti-Viral Interferons• IFNa and IFNb made by virus-
infected cells• Not virus-specific• Bind neighboring host cells and
induce synthesis of anti-viral proteins to block virus replication
![Page 62: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/62.jpg)
Natural Killer Cells
• All nucleated cells in body have membrane MHC = tissue typing antigens
• In virus-infected cells, MHC is reduced in amount or contains virus peptides
• NK cells recognize this ‘altered’ MHC and kill virus-infected cells (also tumor cells)
![Page 63: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/63.jpg)
Role of Natural killer Cells
• Natural killer cells (or NK cells) are a type of cytotoxic lymphocyte that constitute a major component of the Innate immune system. NK cells play a major role in the rejection of tumours and cells infected by viruses. The cells kill by releasing small cytoplasmic granules of proteins called perforin and granzyme that cause the target cell to die by apoptosis
63Dr.T.V.Rao MD
![Page 64: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/64.jpg)
Inflammation• Tissue Injury• Irritation• Arterioles constrict initially and then
dilate• Slow the Blood flow and Margi nation
of Leucocytes • Escape into tissues by diapedesis
and accumulate in large numbers64Dr.T.V.Rao MD
![Page 65: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/65.jpg)
65Dr.T.V.Rao MD
![Page 66: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/66.jpg)
Inflammation
• Outpour plasma, and dilute the toxic material
• Produce fibrin barrier and localized the infection
66Dr.T.V.Rao MD
![Page 67: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/67.jpg)
Fever• Natural defense
Mechanisms• Destroy infectious
agents• Therapeutic –
Trepanoma palladium• Production of
Interferon's
67Dr.T.V.Rao MD
![Page 68: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/68.jpg)
Antibacterial substances in Blood and Tissues
• The complement system possess bacterial activity and plays role in the bactericidal activity and destroys the pathogenic bacteria
• Betalysin – anthrax• Leukins and Plakins• Lactic acid found in muscles • Lacto peroxidase in milk
Dr.T.V.Rao MD 68
![Page 69: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/69.jpg)
Acute Phase proteins too play a great role in Immunity
• Infection and Injury produces Acute phase proteins
• C- Reactive proteins CRP• Mann in binding proteins• CRP activates alternative pathway• Increases host defenses• Prevents issue injury• Repair inflamed lesions.
69Dr.T.V.Rao MD
![Page 70: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/70.jpg)
Acute Phase proteins
• Infection and Injury produces Acute phase proteins
• C- Reactive proteins CRP• Mann in binding proteins• CRP activates alternative pathway• Increases host defenses• Prevents issue injury• Repair inflamed lesions.
70Dr.T.V.Rao MD
![Page 71: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/71.jpg)
Adaptive immunity: second line of response
• Based upon resistance acquired during life• Relies on genetic events and cellular growth • Responds more slowly, over few days • Is specific
– each cell responds to a single epitope on an antigen
• Has anamnestic memory– repeated exposure leads to faster, stronger response
• Leads to clonal expansion
71Dr.T.V.Rao MD
![Page 72: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/72.jpg)
Adaptive immunity: mechanisms
• Cell-mediated immune response (CMIR)– T-lymphocytes– eliminate intracellular microbes that survive
within phagocytes or other infected cells• Humoral immune response (HIR)
– B-lymphocytes– mediated by antibodies– eliminate extra-cellular
microbes and their toxins Plasma cell
(Derived from B-lymphocyte, produces
antibodies)
72Dr.T.V.Rao MD
![Page 73: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/73.jpg)
Cell-mediated immune response
1.T-cell – recognizes peptide
antigen on macrophage in association with major histo-compatibility complex (MHC) class
– identifies molecules on cell surfaces
– helps body distinguish self from non-self
2. T-cell goes into effectors cells stage that is able to kill infected cells
73Dr.T.V.Rao MD
![Page 74: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/74.jpg)
Cell mediated immune response
Primary response – production of specific clones of effector T cells
and memory clones– develops in several days – does not limit the infection
Secondary response – more pronounced, faster – more effective at limiting the infection
Example - cytotoxic reactions against intracellular parasites, delayed hypersensitivity (e.g., Tuberculin test) and allograft rejection
Dr.T.V.Rao MD 74
![Page 75: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/75.jpg)
Humoral immune response1. B lymphocytes recognize
specific antigens – proliferate and
differentiate into antibody-secreting plasma cells
2. Antibodies bind to specific antigens on microbes; destroy microbes via specific mechanisms
3. Some B lymphocytes evolve into the resting state - memory cells
Dr.T.V.Rao MD 75
![Page 76: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/76.jpg)
Antibodies (immunoglobulin's)•Belong to the gamma-globulin fraction of serum proteins•Y-shaped or T-shaped polypeptides
–2 identical heavy chains–2 identical light chains
• All immunoglobulin's are not antibodies•Five kinds of antibodies
– IgG, IgM, IgA, IgD, IgE
![Page 77: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/77.jpg)
Measurement of Immunity
• It is not possible to measure the immunity accurately
• Detection of antibodies• Detected by agglutination tests,
Precipitation tests, complement fixation HI ELISA
• Skin Tests, Schick test , Dick Tests• Tuberculin Test – Delayed Hypersentivity
tests in TuberculosisDr.T.V.Rao MD 77
![Page 78: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/78.jpg)
Local Immunity
• Can be produced by Oral Vaccines• Sabin's vaccine for polio given orally X
Salk will not protect Local Immunity but produces systemic Immunity
• Locally produced Antibodies IgA protect the gut from entry of pathogens
• Local immunity antigen protects the individuals
Dr.T.V.Rao MD 78
![Page 79: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/79.jpg)
Herd Immunity• This indicates the overall level in the
community and important in control of infections in the community (HERD )
• When Herd immunity is low epidemics occur.
• Eradication of communicable diseases depends on the development of high level of herd immunity rather than high level of Individual Immunity
Dr.T.V.Rao MD 79
![Page 80: Introduction to immunology, Science of Immunity](https://reader031.vdocument.in/reader031/viewer/2022013011/554b1858b4c90562098b4eec/html5/thumbnails/80.jpg)
• Programme Created by Dr.T.V.Rao MD for Medical and Paramedical Students
in the Developing World • Email
Dr.T.V.Rao MD 80