Prof. Liliane Schoofs
Samenvatting
immunological
biotechnology
6 sp
KU Leuven
3e bach Biochemie & Biotechnologie
,Inhoudstabel
Inhoudstabel......................................................................................................................................................... 1
1: Basic concepts of immunology ............................................................................................................................ 2
2: Innate immunity: the first lines of defense ........................................................................................................... 12
3: Induced responses of innate immunity ............................................................................................................... 22
4: Adaptive immune system B cell receptor structure, diversity and expression .......................................................... 34
5: T cell receptor & MHC ....................................................................................................................................... 44
6: The diversity and function of MHC ...................................................................................................................... 54
7: Lymphopoiesis: the development of B and T lymphocytes..................................................................................... 60
8: T cell mediated immunity (cellular immune response) .......................................................................................... 78
9: B-cell mediated immune response (humoral immunity) ........................................................................................ 92
1
,1: Basic concepts of immunology
What do you know about the immune system?
1. Some common causes of disease in humans
Microbiology: viruses/bacteria/fungi ↔ Parasitology: worms/protozoa
Enormous variation between infectious organisms
Not all micro-organisms in the body are pathogenic: microbiome in our gut
o Immune system needs different mechanisms to attack and overcome different types pathogens
o Specificity needed
2 mechanisms:
1. Innate immune system: all animals; from birth
a. Works immediately
b. Can’t work without adaptive
2. Adaptive immune system: possible only vertebrates,
research ongoing in invertebrates; more specific
a. Takes a while before acquired (hours)
2. How do pathogens cause disease? How do they enter
the body? Where do they develop/grow/multiply?
↪ Depends on the pathogen and the organism
↪ Bacteria can be in or outside cells
Epithelium: skin, longs, digestive tract…, wounds
- First line of defense
- In contact with the outside
Interstitial space: between cells
Intracellular: can be in the cell or even in a vesicle in the cell
2
, 3. Can we develop the same disease more than once?
↪ Depends on the disease
↪ In most cases you are protected your whole life because you
have made memory-cells after the first infection
Infection – effective immune response – pathogen is cleared – most
effector cells are cleared: death by neglect (their spec Ag can no
longer stimulate their survival) apoptosis – macrophage removal
(membrane lipid phosphatidylserine)
Principles of innate immunity
Main 3 strategies against microbes by the host
1) Avoidance: prevent exposure to pathogens
2) Resistance: reducing or eliminating pathogens
3) Tolerance: prevent immune response against host’s own tissues
Tissue origin of immune cells
All cellular elements of the blood arise from pluripotent hematopoietic stem cells in the bone marrow
↪ It can generate all the possible immune cells
↪ Forms two progenitors: lymphoid and myeloid
Short lived, produced during immune response, leave
blood, migrate to place of infection or inflammation
- Red blood cells
- Platelets
- White blood cells
Both are phagocytic
Uptake of Ag: Release of substances that
- Phagocytosis affect vascular permeability
- Macropinocytosis (allergic responses, protection
of mucosal surfaces)
- Mature form of monocytes circulate in blood
- ILC = innate lymphocyte cell (sensor) - Distinct from tissue resident macrophages originate
- B-cell = bursafabricius in yolk and fetal liver: reside many tissues
- T-cell = thymus
o Not made here, in bone arrow, but they mature there
3
Samenvatting
immunological
biotechnology
6 sp
KU Leuven
3e bach Biochemie & Biotechnologie
,Inhoudstabel
Inhoudstabel......................................................................................................................................................... 1
1: Basic concepts of immunology ............................................................................................................................ 2
2: Innate immunity: the first lines of defense ........................................................................................................... 12
3: Induced responses of innate immunity ............................................................................................................... 22
4: Adaptive immune system B cell receptor structure, diversity and expression .......................................................... 34
5: T cell receptor & MHC ....................................................................................................................................... 44
6: The diversity and function of MHC ...................................................................................................................... 54
7: Lymphopoiesis: the development of B and T lymphocytes..................................................................................... 60
8: T cell mediated immunity (cellular immune response) .......................................................................................... 78
9: B-cell mediated immune response (humoral immunity) ........................................................................................ 92
1
,1: Basic concepts of immunology
What do you know about the immune system?
1. Some common causes of disease in humans
Microbiology: viruses/bacteria/fungi ↔ Parasitology: worms/protozoa
Enormous variation between infectious organisms
Not all micro-organisms in the body are pathogenic: microbiome in our gut
o Immune system needs different mechanisms to attack and overcome different types pathogens
o Specificity needed
2 mechanisms:
1. Innate immune system: all animals; from birth
a. Works immediately
b. Can’t work without adaptive
2. Adaptive immune system: possible only vertebrates,
research ongoing in invertebrates; more specific
a. Takes a while before acquired (hours)
2. How do pathogens cause disease? How do they enter
the body? Where do they develop/grow/multiply?
↪ Depends on the pathogen and the organism
↪ Bacteria can be in or outside cells
Epithelium: skin, longs, digestive tract…, wounds
- First line of defense
- In contact with the outside
Interstitial space: between cells
Intracellular: can be in the cell or even in a vesicle in the cell
2
, 3. Can we develop the same disease more than once?
↪ Depends on the disease
↪ In most cases you are protected your whole life because you
have made memory-cells after the first infection
Infection – effective immune response – pathogen is cleared – most
effector cells are cleared: death by neglect (their spec Ag can no
longer stimulate their survival) apoptosis – macrophage removal
(membrane lipid phosphatidylserine)
Principles of innate immunity
Main 3 strategies against microbes by the host
1) Avoidance: prevent exposure to pathogens
2) Resistance: reducing or eliminating pathogens
3) Tolerance: prevent immune response against host’s own tissues
Tissue origin of immune cells
All cellular elements of the blood arise from pluripotent hematopoietic stem cells in the bone marrow
↪ It can generate all the possible immune cells
↪ Forms two progenitors: lymphoid and myeloid
Short lived, produced during immune response, leave
blood, migrate to place of infection or inflammation
- Red blood cells
- Platelets
- White blood cells
Both are phagocytic
Uptake of Ag: Release of substances that
- Phagocytosis affect vascular permeability
- Macropinocytosis (allergic responses, protection
of mucosal surfaces)
- Mature form of monocytes circulate in blood
- ILC = innate lymphocyte cell (sensor) - Distinct from tissue resident macrophages originate
- B-cell = bursafabricius in yolk and fetal liver: reside many tissues
- T-cell = thymus
o Not made here, in bone arrow, but they mature there
3
