INTRODUCTION TO HUMAN
IMMUNOLOGY
CBI-20803
,Learning goals
• Be able to understand the organization of the immune system
• Be able to understand the concepts of innate and adaptative immunity and their
communication and development
• Be able to understand processes underlying infection and inflammation
• Be able to understand the complex pathology of several chronic diseases such as
Celiac disease, IBD, and Diabetes
Lecture 1&2: Introduction to the immune
system
Main functions:
• Protection against infectious microbes, “non-self”
o Intracellular
▪ Viruses, some bacteria and parasites
o Extracellular
▪ Most bacteria and parasites, fungi
• Protection against modified “self”
o Cancer/tumor cells or transformed cells
Chapter 1: Overview of the immune system
Physical barriers
- Skin: 2m2
- Digestive, respiratory and reproductive tract (mucous membranes): 400 m2
With the help of mucus, tight junctions etc.
,Innate immunity
Any invader that breaches the physical barrier is greeted by the innate immune system: our
second line defense.
Phagocytosis: when an macrophage first
encounters a bacterium, it engulfs it in a vesicle
called a phagosome. The vesicle containing the
bacterium is then taken inside the macrophage,
where it fuses with another vesicle called
lysosome. Lysosomes contain powerful chemicals
and enzymes that can destroy the bacteria
(acidic).
Macrophages produce cytokines: hormone-like
messengers which facilitate communication
between cells of the immune system
The strategy of continual self-renewal insures that
there will always be blood stem cells in reserve to
carry on the process of making mature
blood cells.
Types of innate cells:
• Granulocytes: contain granules
inside that are toxic
o Neutrophil
o Eosinophil
o Mast cell
• Phagocytes: ‘eat’
o Macrophage
o Neutrophil
, Adaptive immune system
Adaptive immunity adapts to defend against specific invaders
- Jenner: Cow pox / vaccination
Antibody: also known as an immunoglobulin (Ig), is a large, Y-shaped protein produced
mainly by plasma cells that is used by the immune system to neutralize pathogens such as
pathogenic bacteria and viruses. They can tag viruses for phagocytic ingestion and can help
keep viruses away from infecting cells.
Antigen: the agent that caused the antibodies to be made, e.g. a virus
Adaptive cells are:
• B cell
o Antibodies are produced by plasma B cells
• Helper T cell
• Killer T cell
• NK cell
Different type of antibodies specific to combat specific pathogens
• IgM
• IgD
• IgG
• IgE
• IgA
Each kind of antibody is produced by B-cells.
Fc region: constant region which can bind to Fc
receptors on the surface of cells such as
macrophages
Fab region: consists of Heavy chain (Hc) and Light chain (Lc) proteins and can bind to
antigens. → antigen binding region
B-cells
B-cells can be activated and secrete antibodies.
In order to protect from every possible invader, we would need 100 million specificities.
B-cells have different DNA → They can re-arrange their DNA and cut parts out. By combining
different DNA segments, they can make specific combinations and cut out the rest. Due to
this, you need fewer genes to make a lot of different combinations
B-cells are made on demand
• Clonal expansion
• Each B-cell is specific for only 1 epitope
o = part of virus or bacterium
o BCR/ Antibody: BCR binds to cognate antigen → proliferation
IMMUNOLOGY
CBI-20803
,Learning goals
• Be able to understand the organization of the immune system
• Be able to understand the concepts of innate and adaptative immunity and their
communication and development
• Be able to understand processes underlying infection and inflammation
• Be able to understand the complex pathology of several chronic diseases such as
Celiac disease, IBD, and Diabetes
Lecture 1&2: Introduction to the immune
system
Main functions:
• Protection against infectious microbes, “non-self”
o Intracellular
▪ Viruses, some bacteria and parasites
o Extracellular
▪ Most bacteria and parasites, fungi
• Protection against modified “self”
o Cancer/tumor cells or transformed cells
Chapter 1: Overview of the immune system
Physical barriers
- Skin: 2m2
- Digestive, respiratory and reproductive tract (mucous membranes): 400 m2
With the help of mucus, tight junctions etc.
,Innate immunity
Any invader that breaches the physical barrier is greeted by the innate immune system: our
second line defense.
Phagocytosis: when an macrophage first
encounters a bacterium, it engulfs it in a vesicle
called a phagosome. The vesicle containing the
bacterium is then taken inside the macrophage,
where it fuses with another vesicle called
lysosome. Lysosomes contain powerful chemicals
and enzymes that can destroy the bacteria
(acidic).
Macrophages produce cytokines: hormone-like
messengers which facilitate communication
between cells of the immune system
The strategy of continual self-renewal insures that
there will always be blood stem cells in reserve to
carry on the process of making mature
blood cells.
Types of innate cells:
• Granulocytes: contain granules
inside that are toxic
o Neutrophil
o Eosinophil
o Mast cell
• Phagocytes: ‘eat’
o Macrophage
o Neutrophil
, Adaptive immune system
Adaptive immunity adapts to defend against specific invaders
- Jenner: Cow pox / vaccination
Antibody: also known as an immunoglobulin (Ig), is a large, Y-shaped protein produced
mainly by plasma cells that is used by the immune system to neutralize pathogens such as
pathogenic bacteria and viruses. They can tag viruses for phagocytic ingestion and can help
keep viruses away from infecting cells.
Antigen: the agent that caused the antibodies to be made, e.g. a virus
Adaptive cells are:
• B cell
o Antibodies are produced by plasma B cells
• Helper T cell
• Killer T cell
• NK cell
Different type of antibodies specific to combat specific pathogens
• IgM
• IgD
• IgG
• IgE
• IgA
Each kind of antibody is produced by B-cells.
Fc region: constant region which can bind to Fc
receptors on the surface of cells such as
macrophages
Fab region: consists of Heavy chain (Hc) and Light chain (Lc) proteins and can bind to
antigens. → antigen binding region
B-cells
B-cells can be activated and secrete antibodies.
In order to protect from every possible invader, we would need 100 million specificities.
B-cells have different DNA → They can re-arrange their DNA and cut parts out. By combining
different DNA segments, they can make specific combinations and cut out the rest. Due to
this, you need fewer genes to make a lot of different combinations
B-cells are made on demand
• Clonal expansion
• Each B-cell is specific for only 1 epitope
o = part of virus or bacterium
o BCR/ Antibody: BCR binds to cognate antigen → proliferation
