1. The document discusses innate and acquired immunity, including both active and passive forms of acquired immunity. 2. It describes antigens and antibodies, including the five classes of antibodies and their structures and functions. 3. The mechanisms of humoral and cell-mediated immunity are summarized, including antigen processing, lymphocyte activation, antibody production, and effector functions.

1. Dr Ambika Jawalkar

2. IMMUNITY
INNATE
NON-SPECIFIC
SPECIFIC
-Species
- Racial
-Individual
ACQUIRED
ACTIVE
Natural Artificial
PASSIVE
Natural Artificial

5.  Epitopes /
determinant sites
 Paratope
 Hapten /
Incomplete antigen

6. Immunogenicity of antigen is determined by,
 Size of molecule
 Foreignness
 Chemical structure
 Susceptibility of the substance to the tissue
enzymes
 Genetic constitution of the host
 Dosage, route & timing of administration

7.  Antigens present on the plasma membrane of
cells of each individual of a species
 Encoded by genes called histocompatability
genes which are collectively called as
MHC – Major Histocompatability Complex
 Genes for MHC are located on chromosome 6,
clustered in a multigene complex of classes I, II, III

9. 9
 Class I – markers that display unique
characteristics of self molecules & regulation
of immune reactions
 Required for T lymphocytes
 Class II – receptors that recognize & react
with foreign antigens. Located primarily on
macrophages & B cells
 Involved in presenting antigen to T cells
 Class III – secreted complement
components, C2 and C4

10. No two persons except identical twins have
the same MHC Proteins
No two persons can have same MHC
proteins on plasma membranes of their
cells
HLA Tissue Typing

11.  Gamma Globulins
 All antibodies are Igs, but all Igs are not
antibodies

14. Structure: Monomer
Percentage serum
antibodies: 80%
Location: Blood, lymph,
intestine
Half-life in serum: 23 days
Complement Fixation: Yes
Placental Transfer: Yes
Known Functions:
Enhances phagocytosis,
neutralizes toxins and
viruses, protects fetus and
newborn.

15. Structure: Dimer
Percentage serum antibodies:
10-15%
Location: Secretions (tears,
saliva, intestine, milk), blood and
lymph.
Half-life in serum: 6 days
Complement Fixation: No
Placental Transfer: No
Known Functions: Localized
protection of mucosal surfaces.
Provides immunity to infant
digestive tract

16. Structure: Pentamer
Percentage serum antibodies:
5-10%
Location: Blood, lymph, B cell
surface (monomer)
Half-life in serum: 5 days
Complement Fixation: Yes
Placental Transfer: No
Known Functions: First
antibodies produced during an
infection. Effective against
microbes and agglutinating
antigens

17. Structure: Monomer
Percentage serum
antibodies: 0.2%
Location: B-cell surface,
blood, and lymph
Half-life in serum: 3 days
Complement Fixation: No
Placental Transfer: No
Known Functions: In
serum function is unknown.
On B cell surface, initiate
immune response

18. Structure: Monomer
Percentage serum
antibodies: 0.002%
Location: Bound to mast
cells and basophils
throughout body. Blood.
Half-life in serum: 2 days
Complement Fixation: No
Placental Transfer: No
Known Functions: Allergic
reactions. Possibly lysis of
worms

20. Role of AMI
 Provides defence against most extracellular
antigens
 Participates in type I, II & III
hypersensitivity reactions
 Associated with certain autoimmune
diseases

21.  Primary Humoral response
 Secondary Humoral response

23. 1. Antigen processing & presentation
2. Recognition of Antigen by
Lymphocytes
3. Lymphocyte activation
4. Production of antibodies
5. Inactivation of antigen / attack phase
/ effector phase

24.  APCs
- Macrophages
- B-lymphocytes
- Dendritic cells / Langerhans cells

25.  B-cells contain surface Igs as receptors
 T-cells contain TCRs
Epitope-binding site
 chain  chain
Variable region
Constant region
Transmembrane region

26.  Blast
transformation
 T-B cooperation
 B- cells form clones
- Plasma cells
- memory B-cells

27. Theories of antibody
production
 Instructive / template
theories
- Direct template theory
- Indirect template theory
 Selective theories
- Side chain theory
-Natural selection theory
-Clonal selection theory

28.  Direct attack on invading agents
* Agglutination
* Precipitation
* Neutralization
* Cytolysis
 Attack through Complement system

29. CLASSICAL PATHWAY
ALTERNATIVE PATHWAY

30. Role of CMI
• Protects against fungi, most of viruses &
intracellular bacteria
• Participates in allograft rejection & GVHD
• Participates in delayed hypersensitivity
reaction
• Provides immunological surveillance &
immunity against cancer

31. 1. Antigen processing & presentation
2. Recognition of Antigen by
Lymphocytes
3. T lymphocyte differentiation /
activation
4. Attack phase

32.  APCs
- Macrophages
- B-lymphocytes
- Dendritic cells / Langerhans cells
 Processing of phagocytosed material
MHC-I (bacterial antigens)
 Processing of antigen derived within cell
MHC-II (viral antigens)

33. Mature T-cells
CD8+ cells
(MHC-I)
CD4+ cells
(MHC-II)

34. Mature T-cells
CD8+ cells
Cytotoxic
T-cells (Tc)
Supppressor
T-cells (Ts)
CD4+cells
Helper
T-cells (TH)
Delayed type
hypersensitivity
T-cells (TD)
T-T Cooperation

35. Role of Tc cells
* perforin mediated killing
* Lysis through cytotoxic substances
* Induction of apoptosis
Role of TH cells
*TH-1 cellssecrete cytokines like IL-2, INF-γ
& TNF-β
*TH-2 cells secrete IL-4,5,6,10 &13
Role of Ts cells
*regulate activity of Tc cells
CMI is a balance between Tc cells & Ts cells

37.  Immune Tolerance
 Immune Modulation
 Autoimmunity
 Hypersensitivity
 Immunodeficiency diseases

38.  Systemic lupus erythematosus
 Rheumatoid arthritis
 Endocrine autoimmunities
 Myasthenia gravis
 Multiple sclerosis

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