1 / 36

Cells, Tissues, & Organs of The Immune System

Cells, Tissues, & Organs of The Immune System. Pin Ling ( 凌 斌 ), Ph.D. ext 5632; lingpin@mail.ncku.edu.tw References: 1. Abbas, A, K. et.al, Cellular and Molecular Immunology (6th ed., 2007), Chapter 3

etta
Download Presentation

Cells, Tissues, & Organs of The Immune System

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, Tissues, & Organs of The Immune System • Pin Ling (凌 斌), Ph.D. ext 5632; lingpin@mail.ncku.edu.tw • References: 1. Abbas, A, K. et.al, Cellular and Molecular Immunology (6th ed., 2007), Chapter 3 2. Male D., J. Brostoff, D. B Roth, and I. Roitt Immunology (7th ed., 2006), Chapter 2

  2. Questions 1. Why is it necessary to vaccinate against tetanus only every 10 years, though antibodies against the toxoid disappear from the circulation within a year? 2. Why is the vaccine against tetanus always effective, whereas the vaccine against influenza protects on some occasions but not others? => Memory lymphocytes are still existed and reactivated instantly. => Toxoid is more stable but influenza changes frequently.

  3. Outline • Cells of the Immune System • Anatomy & Functions of Lymphoid Tissues & Organs • Pathways of Lymphocyte Activation, Recirculation & Homing • Summary & Question

  4. Key concepts about immune cells 1. The principle cells of the immune system: Antigen-presenting cells Lymphocytes => Effector cells 2. All immune cells are derived from “Hematopoietic stem cells” in Bone Marrow (BM) (& Fetal liver during fetus). 3. Immune cells are divided into two major lineages: => Lymphoid & Myeloid => Multiple cell types => express distinct “Surface molecules (markers)” => classification 4. Development and differentiation of different cell types depend on cell interactions and cytokines.

  5. Figure 1-3 Cells of the Immune System-I 1. Originated from Bone Marrow (BM) 2. Two major lineages: - Lymphoid - Myeloid 3. NK cells - Large Granular Lymphocytes (LGL) NK => LGL

  6. Cells of the Immune System-II T lymphocytes are first derived from BM and further developed in Thymus for maturation.

  7. Cells of Adaptive immunity 1. Lymphocytes are the key players of the adaptive immunity. 2. Lymphocytes are able to specifically recognize and respond to diverse antigens. => Antigen (Ag) receptors on lymphocytes => Specificity (Clone), Diversity (Repertoire: total number of Ag-specific lymphocytes in an individual; 107-9), & Memory 3. Lymphocytes are classified into three major groups: - B cells => Antibodies => Humoral immunity - T cells => Multiple subtypes => Cell-mediated immunity & Regulate other immune cells - NK cells => Innate immunity

  8. Classes of Lymphocytes 1. B cells => Plasma cells => Abs 2. T cells: - T helper cells - T cytotoxic cells - T regulatory cells => suppress immune responses 3. NK cells

  9. Identification of cell populations 1. Molecules on or in cells => Identification & Classification 2. Methods: (1) Immunofluorence (2) Flow cytometry & sorting (3) ELISPOT

  10. Lymphocytes

  11. Plasma Cells-Ab Secretion

  12. Cells of innate immunity 1. Innate immune cells are derived from Bone Marrow. 2. Their primary function is to identify and kill microbes. Antigen-presenting cells (APCs) additionally function to present Ag to and activate lymphocytes. 3. Innate immune cells recognize the common microbial structures PAMPs through Pattern-Recognition Receptors (PRRs) -limited diversity.

  13. Classes of innate immune cells Innate immune cells are classified as following: - Monocyte/Macrophage - Dendritic cell (DC) - Polymorphonuclear granulocyte (PMN; Neutrophil, Eosinophil, Basophil) - Mast cell - NK cells (lymphocyte) => Killing virus-infected cells & tumors

  14. Maturation of Macrophages Activated Macro

  15. Dendritic cells as Ag-presenting cells (APCs) APCs link the innate & adaptive immune systems.

  16. Dendritic cells as Ag-presenting cells-II

  17. Outline • Cells of the Immune System • Anatomy & Functions of Lymphoid Tissues & Organs • Pathways of Lymphocyte Activation, Recirculation & Homing • Summary & Question

  18. Primary lymphoid organs: BM & Thymus => Lymphocyte development, selection, & maturation. 2nd lymphoid organs: Lymphoid nodes & Spleen => Lymphocyte activation & effector functions • BM • Other immune cells Ex. DCs, Macrophages, PMNs

  19. The Lymphatic System Link to the blood circulation system

  20. Bone Marrow 1. The site of generation of all immune and blood cells <= Hematopoietic Stem Cell 2. Provides Cell-cell interactions and Cytokines for the development of all immune cells. <= Stromal reticular cells & other cells

  21. B cell development in the Bone Marrow

  22. Thymus-I 1. The site of T cell maturation => Thymus-dependent (T) lymphocytes or T cells => Thymocytes: developing T cells in thymus 2. Upper anterior thorax (above the heart). 3. Multiple lobules => Each has Outer Cortex => Dense T cells Inner Medulla => Sparse T cells Other cells: epithelial cells, DCs, Macrophages => Cell-cell interactions and Cytokines

  23. Thymus-II

  24. 2nd Lymphoid Organ-Lymph Node (LN) LNs => Small nodular organ => Body => Lymphocyte activation Lymphocytes => Segregated in the distinct regions of LN The outer cortex => B cell zone (follicle) => Germinal Center (2nd follicle)=>B cell activation The inner region => T cell zone

  25. Lymph Node (LN)-II

  26. Spleen 1. The site of immune responses to blood Ags => A filter of blood 2. White pulp marginal zone Red pulp 3. T cells => periarteriolar lymphoid sheaths B cells => follicle => marginal zone

  27. Outline • Cells of the Immune System • Anatomy & Functions of Lymphoid Tissues & Organs • Mechanisms of Lymphocyte Activation, Recirculation & Homing • Summary & Question

  28. Overview of Lymphocyte Generation & Activation-I

  29. Overview of Lymphocyte Generation & Activation-II

  30. Activation of Lymphocytes In general, lymphocyte activation requires “Two Signals” (from Antigen presenting cells (APCs)) Signal 1: Ag  Ag receptor on lymphocytes (T & B) Signal 2: Molecules (innate response) Costimulatory receptors on lymphocytes

  31. Migration of Lymphocytes-I 1. In LN, naïve lymphocytes  HEVs Rolling => Adhesion => Transmigration Adhesion molecules for cell-cell interactions 2. In peripheral infection sites, effector lymphocytes  blood vessels

  32. Migration of Lymphocytes-II

  33. Outline • Cells of the Immune System • Anatomy & Functions of Lymphoid Tissues & Organs • Mechanisms of Lymphocyte Activation, Recirculation & Homing • Summary & Question

  34. SUMMARY 1. Immune cells are derived from “Bone Marrow (BM)”. T-lineage progenitor cells are first derived from BM and move to “Thymus” for maturation. 2. Key cells in innate immune responses include - Macrophage & DCs => Ag presentation - Granulocytes (PMNs) - NK cells 3. Key cells in Adaptive immune responses include - B lymphocytes => Ab => Extracellular bacteria - Several T cell types => Fight intracellular microbes & Regulate the program of an immune response 4.Primary lymphoid organs (BM & Thymus)=> immune cell development 2nd lyphoid organs (LN & Spleen)=> Concentrate Ags from tissues or blood for lymphocyte activation.

  35. Question What effect you expect on the immune system if the thymus was removed?

More Related