Lecture 1 – Ch1/2: adaptive immunity
The immune system = ensures we stay healthy
- It is a complex network of interacting cells, cell products, and cell-forming tissue which
protects the body from:
o Pathogens and other foreign substances
o Infected and malignant cells are destroyed (When it is in the beginning phase)
o Removes cellular debris in wound healing
!Without immune system you will not survive!
- It needs to discriminate between “self VS
non-self” and “harmful VS not harmful”
and a disbalance in the immunity
(between inflammation and tolerance)
can cause disease
o Non-self harmful = pathogens
- Infections = if the pathogen is so severe, the body cannot keep up and there
is no inflammation seen, this is called an infection.
o Non-self-harmless = microbiomes in us but also other things from the environment
coming into our body (i.e., pollen)
- Allergies = reaction of the immune system to something that is harmless
o Self harmless = our own healthy tissue and organs
- Auto-immune disease = when our body attacks our own cells
o Self harmful = cancer
- Our own cells frow unnaturally and uncontrollably
Part 1 – innate versus adaptive immunity: components
Our circulatory system consists of multiple immunological components
- White blood cells (leukocytes) = percentage of each in the blood is very different
o Neutrophils
o Eosinophils Hematopoiesis = development of immune cells
o Basophil with two important common precursor
- Hematopoietic stem cells become:
o Monocyte
o Common myeloid cell
o Lymphocyte
precursor = producing the
o Mast cells innate immune cells
- Plasma = complement molecules and o Common lymphoid cell
antibodies in the plasma which you need in precursor (reside in lymphoid
order to stay healthy tissue)= producing the
- Red blood cells adaptive immune cells + NK
- Platelets cells
Types of immune systems
- Circulatory system
o Innate immune system = existing from birth (fast)
- Physical barriers = the first defense mechanism of our body against
pathogens
, - Second line of defense = the cell types in the innate immune system that are
produced when the first line of defense is not enough:
• Granulocytes
o Basophils
o Eosinophil
o Neutrophils
o Mast cells
• Monocytes = Can become:
o Dendritic cells
o Macrophages
o (and mast cells)
! The amount of macrophages, dendritic cells, ( and mast
cells in the blood are very low but high in tissue because the
monocytes become these cells in the tissue and not in the
circulatory system !
• Lymphocytes
o NK cells are in the innate immune system
• Complement system = system of enzyme which complements the
ongoing response
• Dendritic cells
o Third line of defense = Adaptive immune system --> you are born with part of the
adaptive immune cells but during the course of life they adapt
- Lymphocytes =
• Antibodies
• B and T cells
- Dendritic cells = make the B and T cells
Lymphatic system = makes sure that the lymphocytes can go through your body
- Primary and secondary lymphoid organs = important in development and activation of the
adaptive immune system which are connected to the lymphoid system (which I of course
connected to the circulatory system)
, o Primary = for the development of the adaptive immune cells
- Bone marrow = B cells
- Thymus = T cells
o Secondary = activation of the adaptive immune cells
- Lymph nodes
• Are everywhere in our body and have specific sites for T cell and B
cell activation
- Spleen
- Gut associated lymphoid tissue (GALT) = they look like lymph nodes and are
connected to the lymph nodes
Questions part 1
What is correct concerning the innate immune system?
a) Composed of immune cells only
b) Response takes some days to occur
c) Forms first and second line of defense
d) Includes T cells, B cells and antibodies
Which statement is true about lymphocytes?
a) Have same common precursors as myeloid cells
b) Include T cells, B cells and NK cells
c) Can arise from monocytes
d) Are always adaptive immune cells
Part 2
Innate immune system
- Fast and immediate
- Equal in all of us because we are born with it
- Macrophages and neutrophils = induce the inflammation
o Macrophages are in the tissue
- They need the neutrophils because they can increase very fast in number
while the macrophages take some time because they are made from
monocytes (development takes longer)
o Neutrophils are in our blood and scan the environment for possible danger
, - Steps
o Normal healthy skin gets damages
o Bacteria come into the skin
o Macrophages are alerted and eat up the bacteria and secrete signaling molecules
- Release molecules that cause inflammation = fluids coming in, heat, swelling
• Vessels start to widen and they become leaky
• Massive number of neutrophils are recruited
- Neutrophils can now migrate into the tissue using signaling molecules
• Types of signaling molecules:
o Cytokines = molecules for activation
o Chemokines = signaling molecule for migration
o Both neutrophils and macrophages now eat the bacteria up
- The innate immune system uses innate immune cell receptors = they take in pathogens or
activate the immune cells when pathogen binds
o Each immune cell type has the same receptor
o The receptor distinguish self from non-self --> They can differentiate between major
pathogen species = i.e., bacterial VS virus
- They do not know which specific bacterial/viral infection it is
o The receptors use associated molecular patterns = they bind to
- Pathogens associated = PAMPS
- Danger associated = DAMPS
o !No SPECIFIC response --> pathogen will win!
Adaptive immune system
- Dendritic cells in our tissue take up the pathogen
- Migrate to the lymph nodes
- Activate the adaptive immune cells = B and T cells
People with no innate immunity = the
immune system did not work well -->
pathogen load increases
No adaptive immune system = for some time
the pathogen load is kept low, but you need
the adaptive immune system to remove the
pathogen in the long run, so we see an
increase in pathogen load after 1.5-2 weeks
The immune system = ensures we stay healthy
- It is a complex network of interacting cells, cell products, and cell-forming tissue which
protects the body from:
o Pathogens and other foreign substances
o Infected and malignant cells are destroyed (When it is in the beginning phase)
o Removes cellular debris in wound healing
!Without immune system you will not survive!
- It needs to discriminate between “self VS
non-self” and “harmful VS not harmful”
and a disbalance in the immunity
(between inflammation and tolerance)
can cause disease
o Non-self harmful = pathogens
- Infections = if the pathogen is so severe, the body cannot keep up and there
is no inflammation seen, this is called an infection.
o Non-self-harmless = microbiomes in us but also other things from the environment
coming into our body (i.e., pollen)
- Allergies = reaction of the immune system to something that is harmless
o Self harmless = our own healthy tissue and organs
- Auto-immune disease = when our body attacks our own cells
o Self harmful = cancer
- Our own cells frow unnaturally and uncontrollably
Part 1 – innate versus adaptive immunity: components
Our circulatory system consists of multiple immunological components
- White blood cells (leukocytes) = percentage of each in the blood is very different
o Neutrophils
o Eosinophils Hematopoiesis = development of immune cells
o Basophil with two important common precursor
- Hematopoietic stem cells become:
o Monocyte
o Common myeloid cell
o Lymphocyte
precursor = producing the
o Mast cells innate immune cells
- Plasma = complement molecules and o Common lymphoid cell
antibodies in the plasma which you need in precursor (reside in lymphoid
order to stay healthy tissue)= producing the
- Red blood cells adaptive immune cells + NK
- Platelets cells
Types of immune systems
- Circulatory system
o Innate immune system = existing from birth (fast)
- Physical barriers = the first defense mechanism of our body against
pathogens
, - Second line of defense = the cell types in the innate immune system that are
produced when the first line of defense is not enough:
• Granulocytes
o Basophils
o Eosinophil
o Neutrophils
o Mast cells
• Monocytes = Can become:
o Dendritic cells
o Macrophages
o (and mast cells)
! The amount of macrophages, dendritic cells, ( and mast
cells in the blood are very low but high in tissue because the
monocytes become these cells in the tissue and not in the
circulatory system !
• Lymphocytes
o NK cells are in the innate immune system
• Complement system = system of enzyme which complements the
ongoing response
• Dendritic cells
o Third line of defense = Adaptive immune system --> you are born with part of the
adaptive immune cells but during the course of life they adapt
- Lymphocytes =
• Antibodies
• B and T cells
- Dendritic cells = make the B and T cells
Lymphatic system = makes sure that the lymphocytes can go through your body
- Primary and secondary lymphoid organs = important in development and activation of the
adaptive immune system which are connected to the lymphoid system (which I of course
connected to the circulatory system)
, o Primary = for the development of the adaptive immune cells
- Bone marrow = B cells
- Thymus = T cells
o Secondary = activation of the adaptive immune cells
- Lymph nodes
• Are everywhere in our body and have specific sites for T cell and B
cell activation
- Spleen
- Gut associated lymphoid tissue (GALT) = they look like lymph nodes and are
connected to the lymph nodes
Questions part 1
What is correct concerning the innate immune system?
a) Composed of immune cells only
b) Response takes some days to occur
c) Forms first and second line of defense
d) Includes T cells, B cells and antibodies
Which statement is true about lymphocytes?
a) Have same common precursors as myeloid cells
b) Include T cells, B cells and NK cells
c) Can arise from monocytes
d) Are always adaptive immune cells
Part 2
Innate immune system
- Fast and immediate
- Equal in all of us because we are born with it
- Macrophages and neutrophils = induce the inflammation
o Macrophages are in the tissue
- They need the neutrophils because they can increase very fast in number
while the macrophages take some time because they are made from
monocytes (development takes longer)
o Neutrophils are in our blood and scan the environment for possible danger
, - Steps
o Normal healthy skin gets damages
o Bacteria come into the skin
o Macrophages are alerted and eat up the bacteria and secrete signaling molecules
- Release molecules that cause inflammation = fluids coming in, heat, swelling
• Vessels start to widen and they become leaky
• Massive number of neutrophils are recruited
- Neutrophils can now migrate into the tissue using signaling molecules
• Types of signaling molecules:
o Cytokines = molecules for activation
o Chemokines = signaling molecule for migration
o Both neutrophils and macrophages now eat the bacteria up
- The innate immune system uses innate immune cell receptors = they take in pathogens or
activate the immune cells when pathogen binds
o Each immune cell type has the same receptor
o The receptor distinguish self from non-self --> They can differentiate between major
pathogen species = i.e., bacterial VS virus
- They do not know which specific bacterial/viral infection it is
o The receptors use associated molecular patterns = they bind to
- Pathogens associated = PAMPS
- Danger associated = DAMPS
o !No SPECIFIC response --> pathogen will win!
Adaptive immune system
- Dendritic cells in our tissue take up the pathogen
- Migrate to the lymph nodes
- Activate the adaptive immune cells = B and T cells
People with no innate immunity = the
immune system did not work well -->
pathogen load increases
No adaptive immune system = for some time
the pathogen load is kept low, but you need
the adaptive immune system to remove the
pathogen in the long run, so we see an
increase in pathogen load after 1.5-2 weeks
