Cellular Immune Response, Part III Flashcards
CD8+ cells are asssociated with killing cells that are infected. What other roles do they have?
- Eradication of tumors
- Cytokine production
- Acute rejection of organ allografts
What is contained within cytotoxic T cells?
Modified lysosomes with perforins and granzymes
What is cytokine is predominantly produced by TC cells?
IFN gamma
What TF’s, or transcription factors are associated with cytotoxic T cells?
T-bet and Oesodermin
Tumor antigen can be presented via cross-presentation by a small subset of antigen presenting cells. What is meant by cross-presentation?
APC’s that are capable of expressing an antigen without becoming infected and don’t endogenously produce viratl antigens
In weak innate immune responses, CD_+ T helper cells are required. They also may be required for CD_+ T cell responses to latent viral infections.
CD4+
CD8+
Proliferation and differentiation of CD8+ T cells into effector CTL’s and Memory CTL’s, is the reaction stemming from recognition of what interleukin by CD8+ cells?
IL-2
In order for Memory CD8+ T cells to survive, what interleukin is required?
IL-15
What interleukin is produced by CD4+ Tcells to induce CD8+ T cell memory?
IL-21
IL-12 and Type I IFN’s are associated with what response to naive CD8+ cells?
Stimulation and differentiation into effector CTL’s
What are the functions of CD8+ CTL’s?
Secretion of IFN gamma, and eliminating intracellular microbes by killing infected cells
What steps are involved in the process of CTL-mediated cytotoxicity?
- Antigen recognition
- Activation of CTL’s
- Granule exocytosis to target cell
- Release or detachment of CTL’s
While an immunological synapse must be present, what adhesion molecules bound together?
ICAM-1 of the target cell to the LFA-1 of the CTL
Describe the pathway involved with CTL eliminating target cells with their granules?
Granzyme B and Perforin are released into the target cell via an endosome, where they are then released into the cytosol to activate caspases leading to apoptosis
Describe the Fas/FasL killing pathway of CTL’s.
The recognition of CTL’s Fas ligand on the target cells Fas receptor, which leads to apoptosis
In chronic viral infections, CD8+ T cells are initated but fail to eliminate target cells. How does this “exhaustion” occur?
Due to a decreased in IFN gamma production, and increased expression of inhibitory receptors on CD8+ T cells
Feline viral rhinotracheitis, feline calcivirus, canine distemper, and feline leukemia, are all examples of -?
Chronic viral infections
