Lecture 3 Flashcards
Neutrophils recreuited due to…
Vasolidation
Margination
Sticky cell wall
Dendritic cells
MHC class II molecules
Puts peptide(antigen) onto it’s surface, travels to regional lymph node, puts it in contact with lymphocyte which has matching receptors
Specific adaptive immunity
Defends against specific microbes and foreign substances
Invloves memory for previously encountered antigents
B and T lymphocytes
Must recognize the specific antigen to be activated
Helper T cells
Activate B and cytotoxic T cells
B cells
Transform into plasma cells to produce and secrete antibodies
Humoral response: With Antibodies and Complement
Cytotoxic T cells
Attack infected body cells, cancer cells, foreign cells
Cell-mediated response
Macrophage presents antigen to Helper T cell
Puts MHC class 2 molecules to find helper T-cells that have appropriate receptor/connector
Activates helper T-cell
B-cell needs…
Assistance from Helper T cell via release of cytokines for full activation of B-cells so they produce plasma cells which release antibodies and also memory cells
Activation of Helper T Cells
Specific Recognition
- MHC-II + Peptide - T cell receptor
Co-reception
-CD28 - B7
Cytokine Release from APC
-Stimulates
3 stages of adaptive immune response
1) recognition of an antigen by lymphocytes
2)Lymphocyte activation
3) Attack launched by the activated lymphocytes and their secretions
Humoral
B cells:
- transform into plasma cells and produce and secrete antibodies
- Use antibodies and Complement to kill
Helper T-cells are necessary for….
Activation of of B-cells to plasma cells
Activation of Cytotoxic T cells
APC presents antigen and finds B-cell and T-cell with right receptor on it’s surface to start the process… how does it recognize the antigen???
MHC-II molecule bears an antigen which has to be recognized by specific T-cell receptor on helper T cell
B7 - surface of dendtritic cell
CD28 on surface of T helper cell - makes sure we are activating the right cells
Checkpoint Inhibition - why 2 key mechanism is so important
All biological systems need a way to shut off their actions
Need displacement of CD28 from B7
Uses CTL4A or PD1 on T cell surface (It’ll outcompete binding of B7 and replace the binding)
That tells the cell that the threat is over (stop killing)