This document provides an overview of the immune system and immunity. It defines key terms and outlines the history of immunology. It describes the two main types of immunity - innate and adaptive immunity - and compares their attributes. Innate immunity provides immediate response using physical and chemical barriers, while adaptive immunity has antigen-specific memory cells that mount faster responses. The details of innate immunity mechanisms like phagocytosis and complement system are explained. Adaptive immunity involves both cellular and humoral response mediated by T and B cells.

1. Presented By
Tasmina Ferdous Susmi
Dept. of Genetic Engineering and Biotechnology
Jessore University of Science and Technology,

3. Basic definition
History
Types of immunity
Innate and adaptive immunity
Details of innate immunity
Adaptive immunity
Cellular and humoral immunity
Active and passive immunity
Differences of innate and adaptive immunity

4. Immunology:
branch of biomedical that is concerned with
immune system and immunity.
Immune System:
the integrated body system of organs, tissues,
cells and cell products that differentiated self
from non-self and neutralize pathogenic
organism.
Immunity:
the ability of organism to resist a particular
infection or toxicity action.
Immune Response:
any reaction by immune system.

5. 430 B.C. Thucydides
People have been sicked free
from illness
1798 Jenner Vaccination
1880 Pasteur
Attenuated chicken cholera
vaccine
1890 Dehring/ Kitasato
Antitoxin- humoral immunity
hypothesis
1883 Metchnikoff
Endocytosis- cytoimmunity
hypothesis
1905 Pirquet/ Schick Horse serum sickness
1945 Owen/ Burnet Immune tolerance hypothesis
1959 Burnet Clonal selection hypothesis

6. Basic
Principle
• Innate Immune
System
• Adaptive Immune
System
Major
Types
• Humoral or
Antibody
mediated
• Cell mediated
May also
classified
• Active Immunity
• Passive Immunity

7. Innate immunity:
• most ancient line of defense,
some form found in all multi
cellular plants and animals.
Adaptive immunity :
• more recent evolutionary and
evolved in jawed vertebrates.
It complements innate
immunity.

9. Also called natural or native immunity.
Consists of cellular and bio-chemical defense mechanisms.
Responds to non-specific foreign substances
Principle components:
1. Physical and chemical barriers, such as epithelia and
antimicrobial chemicals produced at epithelial surfaces
2. Phagocytic cells (neutrophils, macrophage), dendritic cells
and natural killer (NK), cells and other innate lymphoid cells.
3. Blood proteins, including members of the complement system
and other mediators of inflammation.

11. Innate Immunity
Mainly two types of defense:
1. External Defense.
 Skin; Hairs; Cilia; Tears and
saliva; Cerumen or ear wax;
Mucus membrane etc.
2. Internal Defense.
 Phagocytes
 Natural killer cells
 Inflammation
 Acute-phase proteins
 Fever

13. A process by which certain ,living cells called phagocytes
ingest or engulf non-self particles.
Greek word phagein means “to eat” or “devour” and cyte, the
suffix in biology denoting “cell”.
Essential for fighting infections and for subsequent immunity.
This process depends on:
 Presence of strong electric charge.
 Presence of antibodies and complement components on the cell
surface.
 Surface of the particle.

14. Phagocytes includes:
Neutrophills
Monocytes
Macrophages
Mast cells
Dendritic cells

15. Are lymphocytes in the same family as T and B cells
Best for killing virally infected cells
In detection and controlling early sign of cancer
Activates through activating receptor recognize molecules
that express on the surface of cancer cells and infected cells.
Depends on balance of signals by activating and inhibitory
receptor.

16. Mechanism of
Action
Normal healthy cells express
MHC-I molecules to marks
them inhibited against NK
function.
• MHC-I + inhibitory receptor = no
killing action
 Tumor cells or infected cells
don’t have MHC-I.
• No MHC-I + inhibitory receptor=

17. Inhibition
Activation

18. The reaction of living tissue to either an injury or an infection.
Characterized by heat, redness, swelling and pain.
Process initiated by variety of tissue products such as
histamine, bradykinin, serotonin and prostaglandins.

21. A group of heterogeneous plasma proteins.
Includes C-reactive protein(CRP), serum amyloid A(SAA),
fibrinogen, manose binding proteins, complement
components etc.
In response to tissue damage, secretion of cytokines
stimulates the liver to produce APP.
Function:
 Stimulates phagocytosis.
 Act as opsonins.
 Activates complement system.
 Clumping the invading microbes.

22. The condition of an abnormally high body temperature,
accompanied by increase pulse rate and dry skin.
Physiological response to infection.
Component:
Monocyte
Pyrogens
Hypothalmus

23. Infection
Monocyte
activation
Pyrogen
(cytokines)
Hypothalmus
thermoregulatory
centre
Fever
Lipo-
polysaccharide

24. Entry of foreign substances.
Rushes of immune cell to the infectious site.
Recognition of antigens.
Phagocytosis and killing.
Inflammation induction.
Elimination of antigen or switch on adaptive immunity.
Repair and remodeling.

25. Always not required
whole pathogen.
A part of pathogen
enough for recognition.
Need to match molecular
pattern.
Example
• Specific cell wall
organization of bacteria

26. Responds to specific foreign substances.
Exhibits memory with an enhanced response to subsequent
challenge.
Requires priming specific cells help to start the acquired immune
response.
Cellular immunity: T and B cells.
Humoral immunity: Antibodies.

27. Immunity engage in a cell-to-cell contact.
Causing damage or death to the cells of pathogens, cancer
cells or infected cells.
Includes:
 Phagocytosis of bacteria by neutrophils.
 Action of NK cells.
 Attack of cytotoxic T-cells.

28. Cell Mediated
Immunity of T-cell.

29. Involves not so much of cells directly.
Secretion of antibody.
Neutralizing of toxin through antibody.
Antibody mediated pathway.
Main player B-cell.
Memory response.

30. Humoral or Antibody
Mediated Immunity of B-
cell

34. Attributes Innate Immunity Adaptive Immunity
Response time Minutes/hours Days
Specificity Mainly non-specific
Highly specific; discriminates between
even minor differences
Diversity
A limited number of conserved, germ-
line encoded receptors
Highly diverse; a large number of
receptors arising from genetic
recombination of receptor genes
Memory responses Not really
Persistent memory with, faster
response
Self/non self
discrimination
Perfect; no microbes specific self/ non
self patterns in host
Very good; rarely failure of
discrimination
Soluble component
of blood
Many antimicrobial peptides, proteins
and other mediators
Antibodies and cytokines
Major cell types
Phagocytes; NK cells; other
leukocytes etc
T cells; B cells. Antigen presenting
cells