Lecture 6: Dynamics of Adaptive Immunity, Autoimmunity and Autoimmune Disease Flashcards
What is immunological memory?
Immunity mediated by T-cells and B-cells. These cells will provide protection against reinfection.
The response of memory cells will be faster and and more specific to the pathogen that is infecting the host.
What are the three phases of immune response?
Innate immunity, involving barriers and non-specific immune cells such as neutrophils.
Early induced innate response, which includes responses such as inflammation and recruitment of adaptive cells.
Adaptive response, this involves lymphocytes and memory cells, helps fight pathogen faster than innate.
What happens when the MHCII gene in mice is deactivated?
This results in no MHCII protein and therefore, no CD4+ T cells. Without CD4+ T cells, the mice cannot use helper cells to establish an adaptive response and therefore deal with reinfection poorly.
What mainly handles the reaction to a secondary infection and subsequent infections involving the same pathogen?
Memory lymphocytes are mostly responsible.
What are the two locations where Memory T cells reside after infection?
Memory T cells can reside at the area of infection, these are known as effector memory T cells.
Memory T cells can reside in lymphoid tissues and thus be ‘dispatched’ to other areas of the body.
What is the difference between memory cells and plasma cells?
Plasma cells are terminally differentiated B cells.
CD27 is a marker of human memory B cells.
Memory B-cells need to be reactivated to exert their effects.
What forms of hypersensitivity reactions are caused by which immune components?
Type I: Antibodies (IgE + Mast cells)
Type II: Cytotoxic (IgG/IgM + complement)
Type III: Immune complexes (IgG/IgM + Antigen
Type IV: Delayed (CD8+ CD4+ (ThI))
What classifications of autoimmune diseases are there?
These diseases are single organ diseases or systemic diseases that can be caused by either genetics or an environmental trigger such as in rheumatoid arthritis.
What is the purpose of tolerance mechanisms in the body?
Tolerance systems in the body are designed to prevent autoimmune diseases from developing, by requiring lymphocytes to not react to self antigens in lymphatic nurseries.
How can autoimmune diseases be genetic?
The HLA alleles you have can determine the likelihood of developing an autoimmune disease.
What environmental triggers can cause the development of an autoimmune disease?
Mould (mycotoxin)
Asbestos, dioxins, silica, lead.
Drug induced lupus
Silicone
Pesticides
What mechanisms are linked with the development of autoimmune diseases?
- Over-active positive feedback loops
- Epitope-spreading
- The Toll hypothesis
Explain why over-active positive feedback loops cause autoimmune disease.
Explain how “epitope spreading” can cause autoimmune disease.
Explain what the “Toll hypothesis” is.
