Immunology lecture 1 02.12.2019
At the end of the course, the student is able to:
1. Describe the cellular and molecular structure of the immune system.
2. Explain the function of primary, secondary and tertiary immune organs.
3. Outline the structure and function of the HLA system.
4. Discuss the recognition of intracellular and extracellular antigens by the adaptive immune
system.
5. Explain the use of gene fragment rearrangements in the generation of diversity of T and B
cell repertoire.
6. Outline the sequence of events during activation of adaptive immune cells.
7. Compare the basis for specificity, diversity and memory function between the innate and
adaptive immune system.
8. Contrast the acquisition and maintenance of tolerance versus the induction of immunity
Key concepts in Immunology
- Innate versus adaptive immune system
- Specific versus aspecific immune responses
- Self versus non-self
- Immunological memory
- Immunity versus Tolerance
- Cellular versus Humoral Immunity
- Differentiation and specialization of leukocytes (white blood cells)
- Antibodies: Specificity, selectivity, affinity
History of Immunity
Koch’s postulates
1. The germ is found in diseased but not in healthy organisms
2. The germ can be isolated from the diseased organism
3. The germ causes disease when transferred
4. The germ can be isolated again
Nevertheless, this is not complete
Infectious diseases
- Diphtheria
- Measles
o Immunity in isolated communities is less specific than in big groups.
- Polio – viral disease causing paralysis
- Meningococcal disease – caused by a bacteria that can inhabit the mouth and throat. In rare
occasions, the bacteria can enter the circulations leading to sepsis and meningitis.
o Type C has been nearly eradicated by vaccins in 2002
o Type W has seen a strong increase since 2017, very aggressive, leading to a new
vaccination program for this disease which seems to be effective.
- RSV (respiratory syncytial virus) – a cause of common cold with yearly seasonal epidemics.
o In preterm infants, RSV can cause very severe complications contributing to asthma
inception. Can lead to bronchitis. Seen the fact that it mostly happens in preterm
babies, is due to the fact that the immune system is not fully developed in the lungs.
o No vaccin available yet
Most are treated right now with vaccins
Hepatitis B is hard to treat with vaccins
,Cells of immune system – all originated from the bone marrow
- The hematopoietic cells are not of interest in imm unology, they are crucial in stem cell
formation.
- Tissue-resident leukocytes
The immune response
- Starting with an infection, leading to the innate immune response
o Dendritic cells – inducing adaptive immune response
o NK cells
o Neutrophilic granulocytes – start killing microbes
, - Inducing an adaptive immune response after 12 hours
o Creating memory
The adaptive immune system only recognises proteins (MC proteins). The innate immune system can
recognize DNA (as ssDNA, dsRNA) and many more.
During the adaptive immune response, a large number of receptors is made. In the innate response,
only a limited number of receptors are present.
ILCs: innate lymphoid cells – part of the innate immune system whereas B and T cells are part of the
adaptive immune system.
Antibodies are adaptive
Anti-microbial and complement systems are adaptive
Together they form the humoral immune system
Lymphocyte lymphoblast once getting activated
- Size of cytoplasm increases
- The nucleus is very large in the lymphocyte
Neutrophilic granulocytes kill the microbes themselves, macrophages can also take up microbes by
phagocytosis, but present them to T-cells.
Dendritic cell inducing…
- Cytotoxic lymphocytes antiviral immune response
- Helper T cell immune response
- Regulatory T cell maintenance of tolerance
Lecture 2 cells and tissues of the immune system
Killing of removal of microbes by
- Phagocytosis
- Netosis
o Cells expel their nucleir DNA and form a net
o Formation of neutrophil extracellular traps (NETs). These molecules have
antimicrobial activity. The process is being carried out by neutrophils.
o Deficiencies (in clearing the nets) may lead to SLE or other autoimmune diseases.
- Lysis
- ADCC
Microbes are recognised by the innate immune system via PPRs present on the immune cells.
The PPR detect PAMPs – structures only present in microbes or damaged/dead cells (LPS,
ssDNA, dsRNA etc).
Some PPRs are secreted and present in the serum where they can bind to PAMPs.
They are expressed on the surface of the innate immune cell, the endosome or the cytosolic
compartment. Receptors present in the endosome detect microbial parts that are released
after breakdown.
The main example are the Toll-like Receptors (TLRs)
Way of detecting microbes via TLRs
- Phagocytosis
- IFN
- Production of pro-inflammatory cytokines and chemokines
At the end of the course, the student is able to:
1. Describe the cellular and molecular structure of the immune system.
2. Explain the function of primary, secondary and tertiary immune organs.
3. Outline the structure and function of the HLA system.
4. Discuss the recognition of intracellular and extracellular antigens by the adaptive immune
system.
5. Explain the use of gene fragment rearrangements in the generation of diversity of T and B
cell repertoire.
6. Outline the sequence of events during activation of adaptive immune cells.
7. Compare the basis for specificity, diversity and memory function between the innate and
adaptive immune system.
8. Contrast the acquisition and maintenance of tolerance versus the induction of immunity
Key concepts in Immunology
- Innate versus adaptive immune system
- Specific versus aspecific immune responses
- Self versus non-self
- Immunological memory
- Immunity versus Tolerance
- Cellular versus Humoral Immunity
- Differentiation and specialization of leukocytes (white blood cells)
- Antibodies: Specificity, selectivity, affinity
History of Immunity
Koch’s postulates
1. The germ is found in diseased but not in healthy organisms
2. The germ can be isolated from the diseased organism
3. The germ causes disease when transferred
4. The germ can be isolated again
Nevertheless, this is not complete
Infectious diseases
- Diphtheria
- Measles
o Immunity in isolated communities is less specific than in big groups.
- Polio – viral disease causing paralysis
- Meningococcal disease – caused by a bacteria that can inhabit the mouth and throat. In rare
occasions, the bacteria can enter the circulations leading to sepsis and meningitis.
o Type C has been nearly eradicated by vaccins in 2002
o Type W has seen a strong increase since 2017, very aggressive, leading to a new
vaccination program for this disease which seems to be effective.
- RSV (respiratory syncytial virus) – a cause of common cold with yearly seasonal epidemics.
o In preterm infants, RSV can cause very severe complications contributing to asthma
inception. Can lead to bronchitis. Seen the fact that it mostly happens in preterm
babies, is due to the fact that the immune system is not fully developed in the lungs.
o No vaccin available yet
Most are treated right now with vaccins
Hepatitis B is hard to treat with vaccins
,Cells of immune system – all originated from the bone marrow
- The hematopoietic cells are not of interest in imm unology, they are crucial in stem cell
formation.
- Tissue-resident leukocytes
The immune response
- Starting with an infection, leading to the innate immune response
o Dendritic cells – inducing adaptive immune response
o NK cells
o Neutrophilic granulocytes – start killing microbes
, - Inducing an adaptive immune response after 12 hours
o Creating memory
The adaptive immune system only recognises proteins (MC proteins). The innate immune system can
recognize DNA (as ssDNA, dsRNA) and many more.
During the adaptive immune response, a large number of receptors is made. In the innate response,
only a limited number of receptors are present.
ILCs: innate lymphoid cells – part of the innate immune system whereas B and T cells are part of the
adaptive immune system.
Antibodies are adaptive
Anti-microbial and complement systems are adaptive
Together they form the humoral immune system
Lymphocyte lymphoblast once getting activated
- Size of cytoplasm increases
- The nucleus is very large in the lymphocyte
Neutrophilic granulocytes kill the microbes themselves, macrophages can also take up microbes by
phagocytosis, but present them to T-cells.
Dendritic cell inducing…
- Cytotoxic lymphocytes antiviral immune response
- Helper T cell immune response
- Regulatory T cell maintenance of tolerance
Lecture 2 cells and tissues of the immune system
Killing of removal of microbes by
- Phagocytosis
- Netosis
o Cells expel their nucleir DNA and form a net
o Formation of neutrophil extracellular traps (NETs). These molecules have
antimicrobial activity. The process is being carried out by neutrophils.
o Deficiencies (in clearing the nets) may lead to SLE or other autoimmune diseases.
- Lysis
- ADCC
Microbes are recognised by the innate immune system via PPRs present on the immune cells.
The PPR detect PAMPs – structures only present in microbes or damaged/dead cells (LPS,
ssDNA, dsRNA etc).
Some PPRs are secreted and present in the serum where they can bind to PAMPs.
They are expressed on the surface of the innate immune cell, the endosome or the cytosolic
compartment. Receptors present in the endosome detect microbial parts that are released
after breakdown.
The main example are the Toll-like Receptors (TLRs)
Way of detecting microbes via TLRs
- Phagocytosis
- IFN
- Production of pro-inflammatory cytokines and chemokines
