Lecture: Infection and Immunity
Date: Thursday 22nd February
Time: 11am – 12pm
Immunopathology
This is where immunology causes us disease, due to the genotype, infection etc. We are
going to discuss several things, including:
- Hypersensitivity (type1 = allergy to pollen) – it can be serious or mild.
- Auto (self) immunity – building t cells against our own tissue, causing disease.
- 4 types of sensitivity
- Immunodeficiency disease – body can’t make t cells and need a bone marrow
transplant.
- Transplant rejection – matching donor and recipient but unless we have an identical
twin, we cannot have a 100% match.
Triggers for autoimmunity
Figure 1: Genetic factors depend on what our parents have given us, exposure to the
environment. In some cases, we may have an immune dysregulation. We produce t
regulatory cells that may not work in that individual.
Figure 2: Venn diagram of 4 important factors: Environmental, Genetic, and immune
regulation, which influence autoimmune disease.
Four main causes of autoimmune reactions:
1) Release of normally hidden antigens.
2) Molecular mimicry between foreign and self-antigens.
3) Inappropriate MHC class 2 expression on non-antigen presenting cells (due to high
levels of IFN – gamma present in the tissue.
4) Super antigens that cause a cytokine storm, which activate polyclonal T cells and V
cells.
5) Gender: 78% of autoimmune diseases in the US are in women.
Pathways used in the induction of autoimmunity.
Yellow: represents reasons for setting off an autoimmune response (release of antigens,
molecular mimicry, or inappropriate expression of MHC class 2).
(image on slide)
Sequestered self-antigens.
Example 1: Trauma to your eye socket causes interocular antigens to be released into the
blood stream. The antigens enter local lymph node and activates T cells. T cells migrate out
1
Date: Thursday 22nd February
Time: 11am – 12pm
Immunopathology
This is where immunology causes us disease, due to the genotype, infection etc. We are
going to discuss several things, including:
- Hypersensitivity (type1 = allergy to pollen) – it can be serious or mild.
- Auto (self) immunity – building t cells against our own tissue, causing disease.
- 4 types of sensitivity
- Immunodeficiency disease – body can’t make t cells and need a bone marrow
transplant.
- Transplant rejection – matching donor and recipient but unless we have an identical
twin, we cannot have a 100% match.
Triggers for autoimmunity
Figure 1: Genetic factors depend on what our parents have given us, exposure to the
environment. In some cases, we may have an immune dysregulation. We produce t
regulatory cells that may not work in that individual.
Figure 2: Venn diagram of 4 important factors: Environmental, Genetic, and immune
regulation, which influence autoimmune disease.
Four main causes of autoimmune reactions:
1) Release of normally hidden antigens.
2) Molecular mimicry between foreign and self-antigens.
3) Inappropriate MHC class 2 expression on non-antigen presenting cells (due to high
levels of IFN – gamma present in the tissue.
4) Super antigens that cause a cytokine storm, which activate polyclonal T cells and V
cells.
5) Gender: 78% of autoimmune diseases in the US are in women.
Pathways used in the induction of autoimmunity.
Yellow: represents reasons for setting off an autoimmune response (release of antigens,
molecular mimicry, or inappropriate expression of MHC class 2).
(image on slide)
Sequestered self-antigens.
Example 1: Trauma to your eye socket causes interocular antigens to be released into the
blood stream. The antigens enter local lymph node and activates T cells. T cells migrate out
1
