Podcast
Questions and Answers
What type of immune response do T cells mediate?
What type of immune response do T cells mediate?
Which type of T cell is cytotoxic and kills cells directly?
Which type of T cell is cytotoxic and kills cells directly?
Which type of T cell activates macrophages and allows uptake of pathogens by phagocytosis?
Which type of T cell activates macrophages and allows uptake of pathogens by phagocytosis?
Which type of T cell mediates anti-parasitic response and allergic reactions?
Which type of T cell mediates anti-parasitic response and allergic reactions?
Signup and view all the answers
What do CD8+ T cells bind to?
What do CD8+ T cells bind to?
Signup and view all the answers
On which type of cell are MHC Class I proteins expressed?
On which type of cell are MHC Class I proteins expressed?
Signup and view all the answers
What do MHC Class II proteins display?
What do MHC Class II proteins display?
Signup and view all the answers
Which cells recognize soluble or extracellular pathogens?
Which cells recognize soluble or extracellular pathogens?
Signup and view all the answers
Study Notes
T Lymphocytes
- Cell mediated arm of the adaptive immune response
- Two main populations: CD4+ and CD8+
CD4+ T Cells
- Helper T cells (Th1, Th2, TFH)
- Activate macrophages and allow uptake of pathogens by phagocytosis
- Stimulate production of ROS and NOS
- Mediate destruction of pathogens ingested by macrophages
- Th2 cells: mediate anti-parasitic response, allergic reactions, and activate B cells
CD8+ T Cells
- Cytotoxic T cells (Tc/CTL)
- Cytotoxic and kill cells directly
- Respond to pathogens in the cytosol of target cells
- Prevent the spread of infection by inducing programmed cell death (apoptosis)
T Cell Receptors (TCR)
- Bind to Major Histocompatibility Complex (MHC) proteins
- Two classes of MHC proteins: Class I and II
- MHC proteins bind to peptide fragments from self- and non-self proteins
- Displayed on the cell surface and recognized by T cells
MHC Class I Proteins
- Expressed by all nucleated body cells
- Bind to peptide fragments from cytosolic proteins
- Recognized by CD8+ T cells (Tc)
MHC Class II Proteins
- Expressed by selected immune cells (macrophages, dendritic cells, activated B cells)
- Bind to peptide fragments from vesicular proteins
- Recognized by CD4+ T cells (Th1/Th2/TFH)
T Cell Recognition
- Recognize intracellular pathogens, either infecting a cell directly or taken up by a cell (e.g. macrophage)
- In contrast, B cells recognize soluble/extracellular pathogens
- Together, B and T cells recognize pathogens in all cellular locations
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the cell-mediated arm of the adaptive immune response, including CD4+ and CD8+ T-lymphocytes, their functions and populations such as helper T cells and cytotoxic T cells.
