Regulation of The Immune Response Flashcards
Regulation of the Immune Response (7)
Antigen Antibody Idiotype anti-idiotype network Cytokines Neuroendocrine regulaiton Regulatory T-Cells Microbiome
Cooperation
Dysfunction of the system could cause patho processes 3 systems: 1. NS- neurotransmitters 2. Immune system- cytokines 3. Endocrine system- hormone
Antigen: factors influencing
Amount Quality Presentation Epitopes Intake (route of admin)
Antigen: amount
Decreasing the conc will help in selection of antibody with higher affinity
Antigen: quality
T independent Can be super Atg!! Endogenous: Tc Exogenous: processed: Atg-Th extracellular Atg-B-cell Can be Atg competition Atg aggregation Cross-reactivity- most frequently with lipid and polysaccharide antigens
Comparing antigens and superantigens
Antigens:
- activate T-Cells specifically
- bound to the paratope of the TCR
- can activate less than 0.01% of T-Cells
Superantigens:
- activate T-Cells non-specifically
- bound to Vbeta part of TCR
- can activate 20-30% of T-cells
Antigen: Presentation
MHCI, MHCII, CD1
Dominant epitops
Antigen: Epitops
Conformation
Linear
Immune regulatory effect of antibodies
Blocking of feedback mechanism Ab-mediated suppression BCR-Ig-Atg complex Idiotype, allotype, isotype suppression Maternal abs- vaccination IVIG= intravenous Ig therapy
Antibody mediated Immunosuppression
Atg eliminated due to the immune response decreases the amount of Atg
Decreasing the Atg will also reduce the specific immune response
Idiotype network
The variable part of the Ig has 2 functions:
- paratope: portion of antibody that recognises and binds to specific antigen
- Idiotope: is the unique set of epitopes on the variable region of the antibody
Cytokines
Small glycoproteins
Small number of specific receptors- has large affinity to these
Regulates the immune response, transmits info
-affects the amount and isotype of antibodies
-affects the production of other cytokines
-transcription, transactivation of genes
-antagonistic, additive or synergistic effect
Effects can be: autocrine, paracrine, juxtacrine, endocrine, pleoitropic, redundant etc
Common feature of Lymphokines
Produced by lymphocytes
Are proteins with no Ab activity and no Atg specificity
Short half-life
Hormone-like effect- but only within a short range
Interleukin- allows for communication btw leucocytes
Interleukin 2 IL-2
Source: activated Th, maybe NK or B-Cells
Vit E increases production
Always produced together with IL-2R- autocrine and paracrine
Effect:
1.B-cell: proliferation so ab synth also increases
2.T-Cell: proliferation, cytokine production, cytotoxicity
display of Fas-FasL- ACID
Treg activation and growth
3.NK
4.Macrophage
Interferons
Type 1: plasmocytoid DC
- IFN alpha- 20 different glycoproteins, synth by virus infected leucocytes
- IFN beta- 1 protein, synth by virus infected fibroblasts and epithelial cells
Type 2:
-IFN gamma: immune interferon, synth by activated T-cells and NK cells
TNF beta
T-Cells!!! mainly
B-Cell and lymphotoxin alpha to a lesser degree
TNF- Acts through receptors
over 50 receptors Monomer, dimer and trimer receptors Not on RBC's 500-1000 copies on other cells IL-1 decreases receptor expression IFN increases receptor expression
TNFR-1
Death domain
Apoptosis
On every cell
TNFR-2
On myeloid cells
Sometimes on activated T and B cells
TNFR-3
Liver cells
Only binds TNF alpha
Soluble TNF receptor molecules
Bind TNF outside the cell
Regulate their function
TNF alpha: Induction
LPS Virus Tumour Toxin C5a IFN-gamma IL-2
TNF alpha: Production
Macrophages
CD4+ T-Cell
NK
TNF alpha: Effect
Thrombosis, vasculitis (IL-1) Oncogen activation Ne phagocytosis incr Anti-tumor Fibroblast prolif B-Cell diff Catabolism incr
