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.
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
8.
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
12.
13.
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
19.
20. Role of AMI
Provides defence against most extracellular
antigens
Participates in type I, II & III
hypersensitivity reactions
Associated with certain autoimmune
diseases
25. B-cells contain surface Igs as receptors
T-cells contain TCRs
Epitope-binding site
chain chain
Variable region
Constant region
Transmembrane region
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
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)