Presentation on theme: "Cytokines Cytokines and their Receptors in Inter-Cellular Communication Cytokines-Based Diseases and Cytokine Therapy Folder: Cytokine Cells in the immune."— Presentation transcript:
1 CytokinesCytokines and their Receptors in Inter-Cellular CommunicationCytokines-Based Diseases and Cytokine TherapyFolder: CytokineCells in the immune response must communicate with each other and with their environment in order to carry out their complex regulated functions throughout the host ("systemically'). The cells communicate by contact in some cases, and also by sending and receiving protein signals, the cytokines.Cytokines are signal molecules produced by cells to communicate with receptors on other cells. When cytokines are produced by lymphocytes, they are also called "lymphokines".Updated: November 15, 2012Folder title: Cytokine
2 Key Hematopoietic Growth Factors and Their Targets (Presented in Part 2 under “Cells of the Immune Response”)Key Hematopoietic Growth Factors and Their TargetsRelatively Multi-Specific:Granulocyte-Macrophage Colony-Stimulating Factor GMCSFInterleukin III - IL3Relatively Mono-Specific:Granulocyte Colony Stimulating Factor - GCSFMacrophage Colony Stimulating Factor - MCSFErythropoietin - EPOFolder: CellThis is a repeat of a slide shown in the folder "Cells". Interleukin 3 is an example of a cytokine. The other factors shown here are called growth factors, although they are functionally indistinquishable from cytokines. In fact, one often fudges by calling them "cytokine growth factors".This is the Speaker Note that appeared in "Cells":Some cytokine growth factors exert their effects on a variety of cellular targets. These multiple functions make it more difficult to use such cytokines as pharmaceutical agents because it is more difficult to predict and control their effects.Other cytokines such as erythropoietin have fairly specific cellular targets and produce more predictable effects. Erythropoietin is an important biopharmaceutical produced by AMGEN for the treatment of red-blood cell anemias.
3 Cytokine Table P l eo t r o pic R e d u n d a n t Folder: Cytokine This slide is also a repeat from "Cells".It shows the potential target cells for specific cytokines and growth factors. It reminds us that the cytokines have specific functions to perform, and sometimes they have multiple specific functions. It also reminds us that cytokine signal must be received by potential target cells. In fact it is the presence of specific cytokine receptors that make these cells the cytokine "targets". We saw earlier that IL3 and GMCSF are pleiotropic cytokines. They do multiple functions (reading down the columns). G-CSF, M-CSF, and EPO (Erythropoetic) are more selective and specific in what they do.
4 Activities of Cytokines: What They Do Cytokines in Hematopoiesis Cytokines in Innate and Adaptive immunity
5 Hematopoiesis Lymphocytes Hematopoietic Cytokines and Hematopoiesis: Stem Cell Factor from Bone Marrow Stromal CellsHematopoiesisLymphocytesHematopoietic Cytokines and Hematopoiesis:Immunology, 5th Edition, Figure 12-16,p. 297Myelocytes
6 Stem Cell ProductionMyelocyte ProductionLymphocyte Production
8 The Complexity of Cytokine-Receptor Signaling and Effects What cytokine is being made?When is it being made?At what concentration?How long will it be around?Is it being modified by other proteins?Activated?Degraded?What other cytokines are being made?Do they affect the first cytokine?Do they activate or inhibit the first cytokine?Is the cytokine receptor available on the target cell or cells?Is the receptor being activated or inhibited?Is the receptor defective?Does the receptor have a high enough affinity for the cytokine?
9 Where They Come From: The Discovery of IL1 Cytokines:Where They Come From: The Discovery of IL1How They Work
10 Macrophage to T-Helper Folder: CytokineThe paracrine effect of a cytokine such as IL-1 is enhanced by bringing the cytokine producing cell, in this case the activated macrophage, into close proximity to its target cell, in this case the Helper T-cell. The ideal way to achieve this specific proximity is to have the antigen-presenting activated macrophage physically bonded to the antigen-specific T-cell Receptor of the "correct" T-cell clone. This specific physical bonding involves antigen presentation on a class II MHC protein by the activated macrophage. The activated macrophage is also producing and secreting IL-1. The attached Helper-T-cell naturally experiences the highest concentration of IL-1 at the earliest point simply because the T-cell is close by.
11 Discovery of IL1“PHA” (Phytohemagglutinin) is a mold product that is a T-cell mitogen. That means it stimulates T-cell activation the way an antigen-presenting macrophage would. However, PHA is a polyclonal mitogen, meaning it stimulates T-cells regardless of their antigen specificity. That means that PHA stimulates almost all of the T-cells, not just a small sub-set.PHA = phytohemagglutinin (poly-clonal t-cell mitogen from fungi
18 Table of Redundancy and Pleiotropy Folder: CytokineExamples of pleiotropic effects are seen by reading down the columns for IL-1, Tumor Necrosis Factor alpha, or IL-6.Examples of redundant effects are seen by reading across the rows. For example, all three cytokines can affect the production of pyrogens, agents that elevate body temperature. Allthree affect vascular permeability, or activate B or T-Cells.See Table 15-3, Immunology, 5th Edition, p. 350
19 Cytokines and TH1 and TH2 Helper T-Cell Subsets: Immunological and Pathobiological Effects
20 TH1 and TH2 in Disease Blocked Blocked Folder: Cytokine This is a repeat of a slide shown earlier where two types of helper T-cells are pictured. TH2 cells support the humoral immune response, and TH1 cells support the cellular response. The levels of antagonistic cytokines IL-4 and Interferon gamma affect which type of Helper T-cell is functionally predominant.
21 Dashed -------- arrow indicates blocking response Roles of TH1 and TH2
22 Cytokines and TH1 and TH2 See Table 12-4, p. 315, Top Half Immunology, 6th Edition
23 Functions of TH1 and TH2See Table 4-4, p. 96 for structures and functions of IgG subtypesThe sub-set of Helper T-cells activated (TH1 vs TH2) has a profound effect on the nature of the immune response supported. The outcome of a disease process (leprosy) based on TH1 vs TH2 cell response is shown on the next slide.See Table 12-4, Bottom Half, p315, 6th Edition
24 TH1 and TH2 Helper Cell Subsets in the Pathology and Progression of Infection with Mycobacterium leprae Tuberculoid (Cell-mediated) and Lepromatous (Humoral response) Leprosy (Figure 12-14, Immunology, 6th Edition, p. 318) M-RNA from Tuberculoid or lepromatous lesions analyzed for types of cytokines being producedTH1 activity supports a cellular immune response that keeps the bacterial infection localized into tuberculoid lesions that limit the effects of the disease. TH2 activity supports a humoral response that is ineffective against the disease and that allows the disease to spread to distant sites.
25 Cytokine Receptors in Normal immune Response and in Pathobiology The Specific Cytokines that are present, and their concentrations matter in how the immune response reacts.The presence and structure of cytokines receptors matter just as much as the cytokines themselves.
26 Receptors for IL2 Gamma subunit is used by other cytokine receptors (IL15, IL7, IL9, IL4)
27 General model of cytokine receptors for interleukin and interferon types of cytokines. See figure 12-6 (b) and (c) p. 308, for interleukin (“hematopoietin”) and interferon class of cytokinesSTAT = signal transducers and activators of transcription.See Table 12-2, p. 313 for STAT family of transcription factors associated with different cytokines of the interleukin and interferon series
32 Cytokines, Cytokine Receptors, and Human Disease (Part 3) Cytokine Receptor BlockingChagas Disease (Trypanosoma Cruzi)Severe Immunosuppression of Infectious EtiologyBlocked Expression of IL-2R Alpha SubunitExample organisms potentially producing endotoxins:Neisseria meningitidis, E coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella pneumoniaeExample organisms producing super-antigens:Staphylococcus aureus, Streptococcus pyrogenesSee pages 291 and 292, Kuby, Edition 5
33 Cytokines, Cytokine Receptors, and Human Disease (Part 4) Cytokine Mimics Anti-inflammatory and Immunosuppressive Viral Products as Mimics of Cytokines and Cytokine ReceptorsXSCID
34 Viral Mimics of Cytokines and Receptors Immunosuppression andAnti-inflammatoryEffects of Viral Mimicsof Cytokines and ofCytokine Receptors.(Kuby, 6th Ed., p. 314)Viral Mimics of Cytokines and ReceptorsMacrophage inflammatory proteinChemokines: Small molecular weight polypepetide (90 to 130 amino acid residues) cytokines attracting cells to inflammatory sites. (See pages 329 to 332, Edition 6, Kuby Immunology)See Chapter 15, p. 346, Kuby Edition 5RANTES: Regulated upon activation, T-Cell expressed and secretedMCP: Monocyte chemoattractant proteinMIP: Macrophage inflammatory proteinAlso see complement-protein breakdown productsFor information on chemokines,See Table 13-2, p. 330,and footnotes to Table 13-2,Kuby, 6th Edition.Chemokines are small MW cytokinesthat mostly regulate leukocyte traffickingand adherence but also regulatenon-leukocyte cellular interactions.Monocyte chemoattractantprotein
35 Other Sources of Cytokines used in Host Response to Pathogens: e.g. Mediators in Type I Immediate Hypersensitivity
36 Overview of Mast Cell Mediated Type I Immediate Hypersensitivity: Triggering of Sensitized Cells and Release of Early and Late Mediators: How Do We Treat This???IgEOView
38 Cytokines in Therapy of Diseases Since cytokines have potent activities at low concentrations in controlling responses of host cells to normal and pathological events, can we use Cytokines deliberately in therapy?
43 Turning Down Helper T-Cell and Cytotoxic T-Cell Mediated Auto-immune Responses
44 IL2 is needed to activate T-cells IL2 is needed to activate T-cells. If these are autoreactive T-cells causing autoimmune disease, the effect of IL2 (illustrated with the Black Dots) can be blocked by using an antibody that blocks the IL2 receptor.Similarly, and analog of IL2 that binds to the receptor with high affinity but does not trigger T-cell differentiation and T-cell production of cytokines can prevent the authentic IL2 from reaching its receptor thus turning down the autoimmunity.
45 Autoreactive T-cells can also be shut down and destroyed with toxins bound to IL2 that are brought to the T-cell by the IL2. This is much like antibody-based immuno-toxins where an antibody bring a toxin to a cancer cell based on an antigen that the cancer cell is expressing.
46 Cytokine Activation of Leucocytes in Anti-Leukemia Treatments
47 LAK CellsThis and the next slide show an approach to using IL2 to activate lymphocytes to attack a cancer in a patient. These approaches were developed by Stephen Rosenberg in the 1990’s. You can check to see whether they have been successful in clinical applications over the succeeding years.
49 On a scale of -2 to +2 rate: 1 = -2 = I’m totally lost; 2 = -1 = I’m having a hard time but I get some of it 3 = 0 = I’m doing OK. I get a lot of it. I’ll figure the rest out later 4 = +1 = I’m doing fine. I get most of it; 5 = +2 = This is no problem. Please get moving before I get totally bored