Lect 34 - adaptive immunity

Flashcards covering topics from Lecture 34 on Adaptive Immunity, including leukocytes, antigen presentation, dendritic cells, T cells, MHC molecules, and the processing of antigens.

Leukocytes

White blood cells that are the main cells involved in immunity.

infection and inflammation of tissue

1. Bacteria introduced to the skin where dendritic cells reside

2. Dendritic cells capture bacteria and antigens engulfing them via phagocytosis

3. The dendritic cells carry the remnants of microbes via the lymphatic vessel to the lymph node

   • During this the microbes are processed by dendritic cells into peptides (10-20 amino acids long)

   • These peptides contain a unique code from the microbe which can be used to help the immune system defend itself

4. In the lymph node, T and B cells are activated producing cytotoxic T cells and antibodies

Dendritic Cell is the ____ antigen presenting cell

most potent

Adaptive immunity

• Dendritic cells present peptides on MHC to T cells

• CD4 T cells help B cells make antibody

• CD8 T cells become cytotoxic and kill virus infected cells (through MHC interactions) and cancer cells

What type of T cells help B cells make antibodies?

CD4 T cells

What type of T cells become cytotoxic and kill virus-infected cells and cancer cells?

CD8 T cells

What is the purpose of antigen uptake?

Clearance of pathogens and presentation to T cells

Invertebrates have what type of immunity?

Innate immunity only

vertebrates have what type of immunity

innate and adaptive

vertebrate with special case of innate and adaptive systems

jawless fish

• adaptive system based on different structures compared to other vertebrates

Where are microbes degraded into peptides in the context of exogenous antigens?

Phagolysosome

Where are MHC-II molecules located?

Inside the phagolysosome

Where does peptide loading of MHC-II take place?

Phagolysosome

Where do endogenous antigens originate?

Cell body

Cytoplasmic proteins are degraded here.

Proteasome

Where do peptides produced by the proteasome move to?

ER (Endoplasmic Reticulum)

Peptides are loaded onto this for detection by a CD8 T cell.

MHC-I

what is the process for endogenous antigens

1. viral proteins are overproduced in the cell

2. proteasome recognises overproduction and the proteins are fed into proteasome

3. peptides (10-20 amino acids long) are produced

4. peptides move to ER then to MHC-I for detection by CD8 T cell

what is the process for exogenous antigens

1. virus is taken in via endocytosis

2. microbe degraded in phagolysosome into peptides

3. MHC-II molecules are located in phagolysosome and undergo peptide loading

4. MHC-II move to cell surface for T cell recognition