1 / 39

Cells and Organs of the Immune System Chapter 2

Cells and Organs of the Immune System Chapter 2. Hematopoiesis. HSC (Hematopoietic Stem Cell) Reside in Bone Marrow Pluripotent 1 HSC Per 50,000 BM Cells (~3x10 8 cells in Mouse Bone Marrow) Extremely Proliferative If Need Arises

americus-witt
Download Presentation

Cells and Organs of the Immune System Chapter 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cells and Organs of the Immune SystemChapter 2

  2. Hematopoiesis • HSC (Hematopoietic Stem Cell) • Reside in Bone Marrow • Pluripotent • 1 HSC Per 50,000 BM Cells (~3x108 cells in Mouse Bone Marrow) • Extremely Proliferative If Need Arises • HSC Differentiates to LPC (lymphoid progentor cell) or MSC (myeloid stem cell) • Growth Factors and Cytokines Determine Path • Once LPC or MSC, Committed • Stromal Cells Are Supporting Cells In BM (endothelial, fat cells, fibroblasts, macrophages)

  3. Hematopoietic Growth Factors • Colony Stimulating Factors • 4 types • Multi-CSF (IL-3) • M-CSF (Macrophage CSF) • G-CSF (Granulocyte CSF) • GM-CSF (Granulocyte Monocyte CSF) • EPO (erythropoietin) • Induces production of RBCs

  4. Cell Death • Orderly Self Destruction and Disorderly • Neutrophils (5.0 x 1010) Last For a Few Days • Aberrant Apoptosis Can Give Rise To Leukemia • Apoptosis (orderly) • Reduction In Cell Volume • Chromatin Condensation • DNA Degradation • M Ingest Membrane Bound Bodies • No Inflammation • Necrosis • Bursting of Cell Due To Injury • Contents Released To Environment • Inflammation

  5. Genes Regulating Apoptosis

  6. Detecting Apoptosis Using Flow Cytometry Ceramide Treatment Propidium Iodide Annexin V-FITC

  7. Cells of the Immune System • Lymphoid Cells • B-cells, T-cells and Null cells (NK cells) • 20-40% of body’s leukocytes • 99% of lymph node • If inactivated said to be naïve • Nucleus occupies almost entire cell • 6 m diameter

  8. Lymphoid Cells

  9. Lymphoid Cells

  10. Identifying Cell Using the CD Nomenclature • CD Cluster Of Differentiation • Over 300 CD Markers • T cells, CD4 or CD8 and CD3 • B cells, CD19 • NK cells, CD56 • Monocytes/Macrophages CD14 • Dendritic Cells, CD1c (Human), CD11c (mouse)

  11. Null Cells • Do Not Express Classical Lymphocyte Markers • Predominantly NK Cells (CD56) • Eliminate Tumor Cells and Virally Infected Cells • Express Low Affinity FcRIII (CD16) • Using CD16 They Can Carry Out ADCC • Reduction of MHC I Can Activate Them

  12. Mononuclear Cells Mononuclear Cells • Monocytes in Blood, M in Tissues • Monocytes 5-10 times smaller than M • M Increases Phagocytic Ability • Secretes cytokines and Produces Hydrolytic Enzymes • Named Based on Tissue They Reside • Alveolar (lungs), Kupffer (liver), Microglial (brain), Osteoclasts (bone) • Activated By Phagocytosis or Cytokines (IFN) • Antigen Presenting Capacity Thru MHC II

  13. Monocyte vs M

  14. M Effective APC

  15. M Capturing Bacteria

  16. Dendritic Cells • Professional APCs • Several Types • Langerhans (LC) found in skin • Circuilating DCs • Myeloid (MDC1 and MDC2) • Plasmacytoid • Interstitial DCs, populate organs such as heart, lungs, liver, intestines • Interdigitating DCs, T-cell areas of lymph nodes and Thymic medulla

  17. Dendritic Cells • Scarce Cell Type • Discovered in 1972 • Early 90s Using GM-CSF/IL4 and Later flt-3 limitation Was Overcome • Intense Area of Research • Seemed Promising for Tumor Treatment • Maybe Better for Tolerance

  18. http:www.coleypharma.com Dendritic Cells

  19. Developmental Pathway of DCs

  20. Follicular DCs • Do Not Express MHC II Molecules • Found in Lymph Follicles (Rich in B Cell) • Express FcR For Antibodies and Complement • Ag-Ab Complex Shown To Last Very Long (weeks to months)

  21. Organs Of Immune System • Primary Lymphoid Organs • Bone Marrow and Thymus • Maturation Site • Secondary Lymphoid Organs • Spleen, lymph nodes, • MALT (mucosal associated lymph tissue) • GALT (gut associated lymph tissue) • Trap antigen, APC, Lymphocyte Proliferation

  22. Thymus • Bilobed Organ on Top of Heart • Reaches Max. Size During Puberty • 70g infants, 3 g in adults • 95-99% Of T Cells Die in Thymus • self reactivity or no reactivity to Ag • Consists of Cortex and Medulla • Rat Thymocytes Sensitive to Glucorticoids

  23. Thymus

  24. Lymphatic System • Plasma From Blood Seeps Into Tissue • Interstitial Fluid Either Goes Back or Becomes Lymph • Lymph Enters Lymphatic Vessels • Thoracic Duct Is Largest Lymphatic Vessel Empties Into Left Subclavian Vein • Lymphatic Vessel Depends On Muscle Contractions For Movement • One Way Valves Ensure One Direction • Lymph Nodes Act As Filters For Antigens

  25. Lymphatic System

  26. Lymph Node

  27. Lymph Node • Multiple Afferent Lymphatics • Cortex • B-cells, Follicular DCs, M, GCs, Primary Follicles • Paracortex • TH, M, DCs • Medulla • Plasma Cells • Post Capillary Venule • Allow Lymphocyte Migration From Circuilation Into Lymph Node • One Efferent Lymphatic • Rich In Abs and Lymphocytes

  28. Mucosal Associated Lymphoid Tissue (MALT) • Mucous Membranes S.A=400m2 • Mucous Membr. Most Common Pathogen Entry Site • M.M Protected by MALT • Organization Varies (most organized P.P, Tonsils, appendix • GI Tract, IEL Unique  TCRs • Lamina Propia (below epithelium) M, B cells, TH • M Cell Allows Ag Entry, Unique Architecture

More Related