T cells Flashcards
Signal 3, cytotoxic T lymphocytes, cytokine patterns, cross-regulation, chemokines, receptors, homing, Th1 cells, Th2 cells, Th17 cells, T(FH) negative regulation and Tregs
How do T cells get to the site of infection?
Efferent lymphatic vessels -> thoracic duct -> blood stream
What do Th1 cytokines promote?
Tc killing and macrophage ROS killing
What are the resulting differentiated T cells from activated T cells?
Effector T cells
Does an effector T cell require co-stimulation to act?
No
What are the signal 3 cytokines that regulate differentiation of T helper cell subsets?
Polarizing cytokines
How are different cytokines produced in the presence of PAMPs?
Different PRRs are engaged by different PAMPs
What T cell subsets do IL-12 and IL-4 induce?
IL-12 -> Th1
IL-4 -> Th2
How does signal 3 exert its effect?
Cytokines bind their receptor and induce signaling through STAT proteins
What are some examples of master transcription regulators?
T-Bet (Th1) and GATA-3 (Th2)
What do the master transcription regulators do?
Transcribe genes that code for specific cytokines
Where are Fas ligand and CD40 ligand expressed?
Surface of effector T cells
Fas ligand is used by ______ T cells to exert _________ effect
CD8; cytotoxic
CD40 ligand is used to _________ B cells and innate immune cells
Activate
Do CD8 T cells require co-stimulation?
Yes
IL-2 can be autocrine and paracrine from a Th__ or Th__ cell
1; 17
What do CTLs do?
Recognize and kill infected cells via recognition with their TCR
How are CD8 T cells activated to become cytotoxic effector cells?
By dendritic cells that have high co-stimulatory activity OR by help from CD4 effector T cells and license DCs to cross present
Signaling of which co-stimulatory receptor leads to DC licensing?
CD40
How does cell death occur via CTL?
Fas-FasL mediated killing causes signaling cascade involving cleavage of procaspases -> caspases lead to apoptosis of target cell
What granules do CTLs release to kill infected cells?
Perforin, granzymes
_____________ is a pore-forming protein and punches holes in the membranes and _________ enters to induce apoptosis
Perforin; granzyme
Once granzyme B enters the cytoplasm, it initiates signaling through _____________ cleavage to caspases, leading to cell death
Procaspases
What are important anti-viral cytokines?
Type I IFN