IMMUNOLOGY
LECTURE 1. CHAPTER 1
Martijn Nawijn
Immunology is the scientific discipline that studies the immune system, which serves to protect your
body from infectious agents and cancer. The immune system is an organ, with its cells all over the
body.
The immune system is the organ that should protect you against infectious diseases. The infectious
diseases can be caused by:
• Extracellular bacteria
• Intracellular bacteria
• Viruses
• Fungi
• Parasites
Vaccination is used since 1798. One of the most important
understandings of immunology is understanding that specific
germs can cause specific diseases. A person who participated in
this understanding is Robert Koch. He did a postulate which is a
critical step forward in identifying causal agents:
• The germ is found in diseased but not healthy organisms
• The germ can be isolated from the diseased organism
• The germ causes disease when transferred
• The germ can be isolated again
Infectious diseases:
• Polio: highly contagious virus: paralysis and deformation in 1/200 patients
• Diphtheria: bacterial infection, most common cause of pediatric death before a vaccin became
available. After diagnosis: 10% of patients die with and 50% die without treatment
• Measles: highly contagious virus, with very severe complications and often resulting in death
Studying and understaning the interactions between
infectious agents and the immune system has led to
eradiction of the viral disease smallpox and strong reductions
in the incidence of a large series of other infectious diseases.
With loss of confidence in vaccines, infectious diseases
reappear.
,The 2020 disease Covid-19 caused by the infectious agent SARS-CoV-2.
Severe phenotype in elderly people. This severe stat is associated with acute respiratory
distress syndrome → people cant get oxygen because there lung structure is destroyed by the
immune response to the virus. The fluid will start leaking in the lungs, so you will drown in your
own fluid.
Do vaccines actually help?
Meningococcal disease: caused by a bacteria that can inhabit the mouth and throat. In rare occasions,
the bacteria can enter the circulation leading to sepsis and meningitis, with a death rate of around 10%
and severe complications with the survivors including neurological symptoms, deformations and
amputations. In 202 a vaccination program against type C has nearly eradicated this meningococcus
type
More vaccines are needed. Respiratory Syncytial Virus, a cause of common cold with yearly seasonal
epidemics around the globe. Inpreterm infants, RSV can cause very severe complications, in
susceptible children, also those carried to term, RSV infectionsin the firt year contribute to asthma
inception. In non-western countries, RSV epidemics completely congest the healthcare system. Most
important cause of death in children
Covid 19 vaccine. Mostly directed to the Spike
protein, the protein that the virus uses to enter the
cell in the nose or the airways. This vaccine can be
delivered in various ways. Also inactivated virions
might be used as vaccine. The current vaccines seem
effective in clinical studies.
A successful SARS-CoV-2 vaccine might work through a variety of
immunological mechanisms, involving the innate immune system
and activation of the adaptive immune response and
establishment of meory B cells (antibody production) and
memory T cells (mediated virus response).
,Features of the immune system: specificity, diversity, memory, clonal expansion, specialization,
contraction and homeoastasis, nonreactivity to self
White blood cells, or leucocytes are the most important cells in
the immune system. However, other cells also play an important
role, including epithelial and endothelial cells.
Leucocytes originate from the hematopoietic stem cell.
Mature leucocytes often circulate the body using blood and lymph
system. However, tissue also harbor a large number of specialized
tissue-resident leucocytes.
<<< Important
figure of the immune response
Early response: innate immunity
Adaptive immunity: takes longer
The immune response goes through different phases:
• Anatomic barriers: skin, oral mucosa, respiratory epithelium, intestine
• Complement/ antimicrobial proteins: C3, defensins, RegIII
• Innate immune cells: macrophages, granulocytes, natural killer cells
o Inflammatory inducers: bacterial lipopolysaccharides, ATP, urate crystals
o Sensory cells: macrophages, neutrophils, dendritic cells
o Mediators: cytokines, cytotoxicity
o Target tissues: production of antimicrobial proteins, induction of intracellular antiviral
proteins, killing of infected cells
• B cells/ antibodies, T cells
Innate immune
system vs
acquired/
adaptive immune
system >>>
The different
steps in the immune response start at different moments after
infection and are then active for different time periods as well.
Immunological memory of the adaptive immune system can offer
lifelong protection.
, The immunological memory is dependent on the adaptive immune response. Exam question: which
cells are important for immunological memory: B and T cells
The innate immune response depends on: All of those will immediately start attacking the microbes
as soon as they see them and it will last for hours/days. A typical response of the innate system is an
inflammation, this gives redness, and swelling.
• Epithelial barriers
• Phagocytes
• Dendritic cells
• NK cells
• Complement: soluble proteins that are part of the innate immune system
Slow response is the adaptive immunity. Two parts of this system are B and T lymphocytes, they need
to be educated to recognize the microbe. And will then produce antibodies (case of B cells) or become
effector T cells that kill the infected cells or activate the innate immune cells.
Both the innate and the adaptive immune system
have specificity, although through a different
mechanism. Both the innate and the adaptive
immune system are not responsive to self. The
adaptive immune system has a greater degree of
diversity and has a specific memory response
The immune system can also be divided by
humoral and cellular ^^^^
Cells of the immune system are >>>
LECTURE 1. CHAPTER 1
Martijn Nawijn
Immunology is the scientific discipline that studies the immune system, which serves to protect your
body from infectious agents and cancer. The immune system is an organ, with its cells all over the
body.
The immune system is the organ that should protect you against infectious diseases. The infectious
diseases can be caused by:
• Extracellular bacteria
• Intracellular bacteria
• Viruses
• Fungi
• Parasites
Vaccination is used since 1798. One of the most important
understandings of immunology is understanding that specific
germs can cause specific diseases. A person who participated in
this understanding is Robert Koch. He did a postulate which is a
critical step forward in identifying causal agents:
• The germ is found in diseased but not healthy organisms
• The germ can be isolated from the diseased organism
• The germ causes disease when transferred
• The germ can be isolated again
Infectious diseases:
• Polio: highly contagious virus: paralysis and deformation in 1/200 patients
• Diphtheria: bacterial infection, most common cause of pediatric death before a vaccin became
available. After diagnosis: 10% of patients die with and 50% die without treatment
• Measles: highly contagious virus, with very severe complications and often resulting in death
Studying and understaning the interactions between
infectious agents and the immune system has led to
eradiction of the viral disease smallpox and strong reductions
in the incidence of a large series of other infectious diseases.
With loss of confidence in vaccines, infectious diseases
reappear.
,The 2020 disease Covid-19 caused by the infectious agent SARS-CoV-2.
Severe phenotype in elderly people. This severe stat is associated with acute respiratory
distress syndrome → people cant get oxygen because there lung structure is destroyed by the
immune response to the virus. The fluid will start leaking in the lungs, so you will drown in your
own fluid.
Do vaccines actually help?
Meningococcal disease: caused by a bacteria that can inhabit the mouth and throat. In rare occasions,
the bacteria can enter the circulation leading to sepsis and meningitis, with a death rate of around 10%
and severe complications with the survivors including neurological symptoms, deformations and
amputations. In 202 a vaccination program against type C has nearly eradicated this meningococcus
type
More vaccines are needed. Respiratory Syncytial Virus, a cause of common cold with yearly seasonal
epidemics around the globe. Inpreterm infants, RSV can cause very severe complications, in
susceptible children, also those carried to term, RSV infectionsin the firt year contribute to asthma
inception. In non-western countries, RSV epidemics completely congest the healthcare system. Most
important cause of death in children
Covid 19 vaccine. Mostly directed to the Spike
protein, the protein that the virus uses to enter the
cell in the nose or the airways. This vaccine can be
delivered in various ways. Also inactivated virions
might be used as vaccine. The current vaccines seem
effective in clinical studies.
A successful SARS-CoV-2 vaccine might work through a variety of
immunological mechanisms, involving the innate immune system
and activation of the adaptive immune response and
establishment of meory B cells (antibody production) and
memory T cells (mediated virus response).
,Features of the immune system: specificity, diversity, memory, clonal expansion, specialization,
contraction and homeoastasis, nonreactivity to self
White blood cells, or leucocytes are the most important cells in
the immune system. However, other cells also play an important
role, including epithelial and endothelial cells.
Leucocytes originate from the hematopoietic stem cell.
Mature leucocytes often circulate the body using blood and lymph
system. However, tissue also harbor a large number of specialized
tissue-resident leucocytes.
<<< Important
figure of the immune response
Early response: innate immunity
Adaptive immunity: takes longer
The immune response goes through different phases:
• Anatomic barriers: skin, oral mucosa, respiratory epithelium, intestine
• Complement/ antimicrobial proteins: C3, defensins, RegIII
• Innate immune cells: macrophages, granulocytes, natural killer cells
o Inflammatory inducers: bacterial lipopolysaccharides, ATP, urate crystals
o Sensory cells: macrophages, neutrophils, dendritic cells
o Mediators: cytokines, cytotoxicity
o Target tissues: production of antimicrobial proteins, induction of intracellular antiviral
proteins, killing of infected cells
• B cells/ antibodies, T cells
Innate immune
system vs
acquired/
adaptive immune
system >>>
The different
steps in the immune response start at different moments after
infection and are then active for different time periods as well.
Immunological memory of the adaptive immune system can offer
lifelong protection.
, The immunological memory is dependent on the adaptive immune response. Exam question: which
cells are important for immunological memory: B and T cells
The innate immune response depends on: All of those will immediately start attacking the microbes
as soon as they see them and it will last for hours/days. A typical response of the innate system is an
inflammation, this gives redness, and swelling.
• Epithelial barriers
• Phagocytes
• Dendritic cells
• NK cells
• Complement: soluble proteins that are part of the innate immune system
Slow response is the adaptive immunity. Two parts of this system are B and T lymphocytes, they need
to be educated to recognize the microbe. And will then produce antibodies (case of B cells) or become
effector T cells that kill the infected cells or activate the innate immune cells.
Both the innate and the adaptive immune system
have specificity, although through a different
mechanism. Both the innate and the adaptive
immune system are not responsive to self. The
adaptive immune system has a greater degree of
diversity and has a specific memory response
The immune system can also be divided by
humoral and cellular ^^^^
Cells of the immune system are >>>
