Morphology, functions and potential application of T Lymphocytes

Morphology, functions and potential application of T Lymphocytes GROUP Outline •Introduction •Morphology of T Lymphocyte •Functions of T Lymphocyte •Potential application of T Lymphocytes Introduction T lymphocyte is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity In this immunofluorescence image, a cytotoxic T cell (blue) A patch of signaling molecules (pink) Lytic granules (red), the microtubule cytoskeleton (green) Scanning electron micrograph of a human T lymphocyte (also called a T cell) from the immune system of a healthy donor Credit: NIAID Morphology of T Lymphocytes •T-Lymphocytes are a type of white blood cells that play a role in cell-mediated immunity.(1) •Blood T and B lymphocytes are indistinguishable by light and electron microscopy •The difference between T lymphocytes and B lymphocytes are difference of diameter Morphology of T Lymphocytes •T cells are about 7-8 micrometers •Small amount of light blue cytoplasm •Coarsely clumped chromatin •Nucleus is round oval in shape Morphology of T Lymphocytes The surface of each T cell also displays thousands of identical T cell receptors (TCRs) There are two types of T cells that differ in their TCR: ◦ Alpha/beta (αβ)  T cells ◦ Gamma/delta  (γδ) T cells Morphology of T Lymphocytes Alpha/beta (αβ) T cells Their TCR is a heterodimer of an alpha chain with a beta chain Morphology of T Lymphocytes Gamma/delta (γδ) T cells Their TCR is also a heterodimer of a gamma chain paired with a delta chain Morphology of T Lymphocytes Most of the T cells in the body belong to one of two subsets These are distinguished by the presence on their surface of one or the other of two glycoproteins designated: • CD4 • CD8 Morphology of T Lymphocytes CD8+T cell CD4+T cell DR.TV.Rao MD Perforin Cytotoxic T Cells Forming of perforin on surface of infected cell Cytotoxic T Cells Hole-forming and entering of granzyme Cytotoxic T Cells Cell death Memory T cells To be activated by antigens but not enter in circulation, remain in lymphoid organs A small fraction of active CD8+ T cell persist to generate pool of a long-lived memory Self-renew and protect against infection The basis of vaccination Memory T Cells Memory T cell make and store up triacylglycerols (TAGs/fat) in order to process long-term This storage of fat is enabled by sophisticated interplay of communication between T cell and IL-7 Memory T Cells  Chemical reaction with IL-7 stimulated T cell to express a glycerol channel called aquaporin-9  Aquaporin-9 imports glycerol and express enzyme for TAGs synthesis  Therefore memory T cell have raw material and enzyme need to make biofuels-> burn fat for making energy-> memory T cell survival and enable protect us from infection  Interleukin-7 keep memory T cell alive Summary T cells Helper T cell Suppressor T cell Cytotoxic T cell Memory T cell Functions Assist other white blood cells in immunologic processes Actively suppress activation of the immune system and prevent pathological self-reactivity Destroy virally infected cells and tumor cells Subset of infection Potentially cancer-fighting T cells Application • FURTHER RESEARCH FOR CANCER • MEDICAL RESEARCH REFERRING TO IMMUNE AND AUTOIMMUNE DISEASES, TRANSPLANTATION, DIABETES Further Research For Cancer • Cancers can be shut off by anti-tumor T-cells, thereby promoting their survival • To be able to prolong the time period a patient, but they have not been able to fully cure cancer • ACT is build from T-Cells, which in turn is engineered to produce receptors called Chimeric Antigen Receptors (CAR T -cell) • CAR T-cells are powerful tools that target and destroy cancer cells Chimeric antigen receptors (CARs): Anatomy and evolution of CAR design A CAR consists of a polypeptide that is the single-chain variable fragment (scFv) from an antibody, linked to the signaling machinery of a T-cell receptor, typically the ζ chain  The scFv binds to a defned target antigen and triggers effector cell activation upon target engagement Chimeric antigen receptors (CARs): Anatomy and evolution of CAR design CAR T cells can recognize a variety of cell surface antigens without the constraint of major histocompatibility complex (MHC) human leucocyte antigen (HLA) class restriction Medical Research Referring To Immune And Autoimmune Diseases, Transplantation, Diabetes Jeff Bluestone Altering positive signals delivered by T-cells (antigen specifc) and costimulatory signals controls T cell signaling pathways Research in more costimulatory molecules (4-1BB, PD-1, ICOS and CD40L) in organ transplantation and diabetes development Medical Research Referring To Immune And Autoimmune Diseases, Transplantation, Diabetes Abul Abbas Regulation of T cell responses and the signals that choose between effector and regulatory cells and between lymphocyte activation and tolerance Mike McCune Pathogenic mechanisms of HIV-1 and T cell repletion and depletion in living organisms (mice) aimed at protecting the body from HIV References  https://infogr.am/177d7eda-3f8f-4632-ad63-ee8f1abe0a86  https://www.youtube.com/watch?v=uwMYpTYsNZM  https://www.jax.org/news-and-insights/jax blog/2016/february /car-t-cell-therapy-are-we-there-yet  http://www.targetedonc.com/publications/targeted-therapies-cancer/2015/june -2015/engineered-t-cells-for-leukemia-a-review-of-current-approaches-and-applicati ons  D.I Strokotov, M.A Yurkin, K.V Gilev, D.R van Bockstaele, A.G Hoekstra, (2009) Is there a difference between T- and B-lymphocyte morphology? Journal of Biomedical Optics  Kimball, J W (2015, August 17) B Cells and T Cells Retrieved from Kimball's Biology Pages: http://www.biology-pages.info/B/B_and_Tcells.html  Ronald A Bergman, Adel K Aff, Paul M Heidger, Jr (n.d.) Atlas of Microscopic Anatomy Retrieved from Anatomy Atlases: http://www.anatomyatlases.org/MicroscopicAnatomy/Section04/Section04.shtml THANKS FOR YOUR ATTENTION