Immunology week 6 Flashcards
What is the specific effect that TLR have on MHC molecules
TLR are a sensing system. APCs use them to detect pathogens and initiate immune
responses by 1. Production of cytokines that activate the APCs themselves, hence the
increase in expression of MHC molecules, 2. Production of chemokines and recruitment
of other immune cells to sites of infection, 3. Increased uptake of pathogens for antigen
processing and presentation.
Are superantigens T dependent AG?
Superantigens are not T-dependent. They interact directly with T cells. Their direct
interaction with B cells (a different mechanism) does not lead to antibody production,
instead leads to B cell apoptosis. I do not teach superantigen effect on B cells, as it is not
very clear what the mechanism is, and moreover it is limited to certain Staphylococcal
antigens, and does not elicit a protective mechanism but rather an immune evasion of
Staphylococcal pathogens such as S. aureus.
The first part is a duplicate of wk 5
specifically
AG processing &
Presentation see wk 5 cards 2-44
Cytokines,
Chemokines,
receptors
Immune response is only possible when ?
Interxn is coordinated by?
Immune response is only possible when interxn between hematopoietic,
lymphoid, & inflammatory cells is possible
○ Interxn is coordinated by cytokines
Definitions:
cytokines=
cytokines= low molecular weight proteins or glycoproteins mainly
produced by lymphocytes and other cells in the body
Definitions:
chemokines=
chemokines= recruit and activate leukocytes
Definitions:
chemotaxis=
chemotaxis= phenomenon in which cells move from an area of low chem
signal to an area of high chem signal
Properties of cytokines
They bind to their receptors on target cells with ?
They bind to their receptors on target cells with high affinity
Properties of cytokines
what is Autocrine?
Autocrine- cytokines can bind to a receptor located on the same cell
Properties of cytokines
What is Paracrine?
Paracrine- cytokines can bind to a receptor found on a neighboring cell
Properties of cytokines
What is Endocrine?
Endocrine- cytokine can bind to a receptor found on a distant target cell
Properties of cytokines
what is: Pleiotropic action-
Pleiotropic action- one cytokine can have different biological effects on
target cells
Properties of cytokines
What is Redundant action?
Redundant action- 2+ cytokines exert the same effect on the same cell
Properties of cytokines
What is Synergistic action?
Synergistic action-effect of 2+ cytokines is greater than the additive
effect of individual cytokines
Properties of cytokines
What is Antagonistic action?
Antagonistic action-action of 1 cytokine inhibits the effects of another
cytokine
Properties of cytokines
What is Cascade action?
Cascade action- action of a cytokine leads to the induction of 1 or more
cytokines which activate others (domino effect)
Properties of cytokines
can they act in a specific or nonspecific manner?
They can act in a nonspecific manner
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
Growth factors- ?
how expressed?
Growth factors- expressed constitutively
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
Hormones and cytokines are expressed in response to ?
Hormones and cytokines are expressed in response to discrete stimuli
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
are cytokines short or long lived?
Cytokines- short- lived
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
Hormones- are they endocrine, autocrine, paracrine?
cytokines-are they endocrine, autocrine, paracrine?
Hormones- endocrine manner
cytokines-endocrine, autocrine, paracrine
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
Hormones- produced by what?
Hormones- produced by special glands
Cytokines, hormones, growth factors
All 3=secreted factors but they have different expression
Cytokines- produced by what?
Cytokines- produced by many different cells
Cytokines, hormones, growth factors
Functions of cytokines:
(5)
Functions of cytokines
○ Cellular and humoral immunity
○ Inflammatory response
○ Hematopoiesis- what is this?
○ Reg. of intensity and duration of IR
○ Wound healing