Cytokines Flashcards
What drives the proliferation and differentiation of activated T cells
The cytokine interleukin -2
IL-2 receptor subunits
alpha (missing in naive T cell receptor), beta, gamma
Both B and T cell activation require
Antigen recognition, co-stimulatory signal, cytokines
The 3 different ways cytokines can act on a cell
Paracrine, autocrine, endocrine
What is pleiotropy
When one gene influences 2 or more seemingly unrelated phenotypic traits
What do activated Th cells secrete and what does it do?
IL-4 acts on B cells (activation, dy/dx and prolif), thymocyte (prolif), mast cell (prolif)
What 4 structurally distinct families do cytokines belong to?
Haematopoietins, interferons, chemokines, TNFs
What do haematopoietic cytokines do?
Support growth and differentiation of haematopoietic cells
What can cytokines do to B cells
Induce switch to different antibody isotype
What 5 structurally distinct families do cytokine receptors belong to?
- Immunoglobulin superfamily receptors 2. Class I cytokine recpetors (haematopoietin) 3. Class II cytokine receptors (interferon) 4. Chemokine receptors 5. TNF receptors
What helps save redundancy of action and antagonism (competition) between cytokines in subfamily?
Sharing subunits
What signal transduction pathway is used by most class I and class II cytokine receptors
JAK-STAT pathway
What affects CD4 T cell differentiation?
Cytokines elicited by pathogens
What promotes the differentiation into Th1
IFN-gamma
What promotes differentiation into Th2
IL-4 and IL-5
