B and T cell Cytokines Flashcards
What are the two main groups of chemokine
CC = which bind to receptors CCR1 to 9 CXC = which bind to CXCR1 to 5
Chemokine IL-8
its source is from (Micheal makes fucking Klass elephants) Monocytes Macrophages Fibroblasts Keratinocytes Endothelial cells TARGETS: - neutrophils - Naive T cells CAUSE: - angiogenesis - activates, mobilises and degranulates neutrophils
chemokine IL-2
Sources:
- THO, TH1 and some CTL
Had large impacts in T cells as they stimulate growth (multiplication and expansion in numbers)
- stimulates growth in NK cells
Chemokine IL-4
Source: - TH2 molecules Has large impacts on B cells such as: - Growth - Activation of IgG1 and IgE - Increase in MHC II induction Also effect T cells by: - Growth - Survival IMMUNOGLOBULIN SWITCHING
Interferon Gamma
Source: - TH1, CTL has a large effect on macrophages: - Activation - increase in MHC I and MHC II representation Causes mass up-regulation
tumour necrosis factor alpha (TNF-alpha)
SOURCE:
- TH1 and TH2 and some CTL
This is a pro-inflammatory which is present in the serum and the joint of people with rheumatoid arthritis
IL8
chemotactic factor, recruits neutrophils and T cells to site of infection
IL2
activates Tcells, proliferation
IL4
activates B cells, switches them to produce
IgE, therefore important in allergy
IFN-gamma
activates strong cell mediated responses, eg CTL
TNF-alpha
activates vascular endothelium and increases vascular permeability
IL1
- pyrogenic
- activates vascular endothelium
- activates lymphocytes
- local tissue destruction
- increases access to effector cells
IL12
activates natural killer cells
induces the differentiation of CD4 T cells into TH1 cells
what is diapedesis
the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation
THIS IS ENCOURAGES BY THE IL8 CHEMOKINE
T cells secrete IL-2 that induces self proliferation - describe
the naive T cells express, at first a low affinity for the IL-2 receptor
However once the cell has been activated this then presents a high affinity for the IL2 receptor and itself secretes the IL2 which then binds to the receptors on the surface
- this then sends a signal to the T cells and induces T cell proliferation
what are the two types of cd4 cells
TH1: cell mediated immunity
- macrophage activation
- B cell proliferation
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- production of opsonising antibodies such as IgG1
TH2: antibody responses
- general activation of B cells to make antibodies
how do TH2 cells activate B cells
the antigen recognition induces expression of CD40 ligand and cytokines by the TH2 cell, this then activates the B cell which leads to proliferation and differentiation to antibody-secreting plasma cells
dendritic cells
thee are located at the interface between the innate and the adaptive immune response
these are found on the surface f most surface epithelia
- these are highly phagocytic as their role is to sample the external environment and once they are stimulated the cease phagocytosis and migrate to lymph nodes
the main names I must know them by are:
- langherans cells in the skin
- follicular dendritic cells FDC
- when they migrate in to the circulation they are known as veiled cells
when the dendrtiic cells are in the lymph nodes then what do they do
- recruiting B cells they enter the lymph organs through high endothelial venules
- the antigen specific B cells are trapped by the antigen specific TH2 cells and are stimulated to proliferate
- B cells migrate to the medulla and differentiate into plasma cell
- then antigen complexes bind to FDC
- a few activated B cells migrate into a nearby follicle forming a germinal centre where rapid proliferation and somatic mutation occur
- mutated B cells that retain the capacity to bind antigen on follicular dendritic cells survive whereas other die
- activated B cells producing high-affinity Ig migrate in blood and becomes plasma cells in the bone marrow
once the FDC is bound to the antigen what happens
these can hold them for an extended period of time, possibly days.
This antigen. is in the form of antigen-antibody-complement complexes
- these are bound to the Fc and complement receptors on the FDC surface
what is the differences between immature and mature dendritic cells
immature = expresses molecules mature = expresses more molecules
what systems allow the recognition of non-self antigens
Pattern recognition receptors
Toll-like receptor family
TLR4
Lipopolysaccharide, heat shock proteins
