1 / 28

The Adaptive Immune Response

The Adaptive Immune Response. Jeffrey Tso Karen Ka Yan Ng Kaitai Ye Marina Simeonova. PHM142 Fall 2014 Instructor: Dr. Jeffrey Henderson. Time course of the Adaptive Immune Response. Janeway’s Immunobiology , 2012. Antigen Processing, Prep and Presentation.

konala
Télécharger la présentation

The Adaptive Immune Response

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. The Adaptive Immune Response Jeffrey Tso Karen Ka Yan Ng Kaitai Ye Marina Simeonova PHM142 Fall 2014 Instructor: Dr. Jeffrey Henderson

  2. Time course of the Adaptive Immune Response Janeway’sImmunobiology, 2012

  3. Antigen Processing, Prep and Presentation Janeway’sImmunobiology, 2012

  4. Dendritic Cell Path

  5. Stimulation of T cells by Dendritic Cells Janeway’sImmunobiology, 2012

  6. Stimulation of T cells by Dendritic Cells Janeway’sImmunobiology, 2012

  7. T Cell Proliferation and Differentiation Janeway’sImmunobiology, 2012

  8. Effector T cell Differentiation • Activated T cells become effector T cells, and differentiate to fill various roles. The role depends on the type of interleukins that the cells are exposed to. • Types of T cells include: Janeway’sImmunobiology, 2012

  9. Cytotoxic T cells Janeway’sImmunobiology, 2012

  10. T Helper Cells Janeway’sImmunobiology, 2012

  11. T Helper Cells Janeway’sImmunobiology, 2012

  12. T Regulatory Cells (Tregs) • Help regulate the immune response • Suppress activation of immune system when no infection present • Down-regulated in times of infection • Deficiencies in regulatory T cells can lead to autoimmune diseases

  13. T Cell Independent B Cell Activation • Naïve B Cell recognize free (soluble) antigen using their BCR or membrane bound-immunoglobulin. • Rapid response, no isotype switching, no affinity maturation

  14. T Cell Dependent Linked Recognition • For Thymus Dependent (TD) Antigens • Antigen-MHC Signal- B Cell Antigen MHC 2 – T Cell Receptor (TCR) • T Cell induced to express CD40 Ligand, CD30 Ligand- B Cell CD40, CD30 • T Cell secretes cytokines ie. IL4,5,6 and B Lymphocyte stimulator (BLyS) • Slower response, isotype switching, and affinity maturation Janeway’sImmunobiology, 2012

  15. Janeway’sImmunobiology, 2012

  16. Isotype Switching Janeway’sImmunobiology 2012

  17. Isotype Switching • Antibodies as know as immunoglobulins are molecules ranging from 146-188kDa and 980kDa for IgM. • Important to form tailored antibodies to the infection • Vh, Vl, C domain • Naive B Cells express primarily IgM and IgD, but serum levels of IgM are less than 10%, with IgG being the most abundant • Th Cell CD40 Ligand, IL4, TFG-Beta, INFy- alternate splicing of Ig mRNA • Light chain variable for every pathogen depending on the presented antigen

  18. Purpose of Antibodies • Opsonize Pathogens (IgGs) • Neutralize Toxins (IgG and IgA) • High affinity Ig’s may limit viral infectivity (IgA and IgG vs hemagglutininin influenza) • Activate complement

  19. TYPES OF ACTIVATED B CELLS PLASMA B CELLS MEMORY B CELLS B-1 CELLS B-2 CELLS Marginal Zone B cells Regulatory B cells

  20. Plasma B cells • Also known as Plasma cells, plasmocytes, effector B cells • Large B cells that have been exposed to antigen secrete large amounts of antibodies • Assists in the destruction of microbes  easier target for phagocyte + activation of complement system

  21. Plasma B cells • Sometimes referred to as antibody factories • Large amounts of Rough ER (to synthesize the antibody) • Short lived, undergo apoptosis when the inciting agent that induced immune response is eliminated.

  22. Memory B cells • Differentiate from activated B cells predominately from a germinal center. • Specific to the antigen encountered during the primary immune response • Able to live for very long time • Can respond quickly following a second exposure to the same antigen

  23. B-1 Cells • Express IgM in greater quantities than IgG • Low in numbers in the lymph nodes and spleen and are instead found predominantly in the peritoneal and pleural cavity

  24. B-2 Cells • Cells intended when using the unqualified “B cell” • Majority in the spleen and lymph • Cells are small, long lived resting cells that express low levels of surface IgM and high amounts of IgD • Unlike B-1 cells, these cells do not express CD4 antigen found on all T cells

  25. Regulatory B Cells • B cells involved in immune regulation via various mechanism • Also known as Breg cells • Positive regulators of immune because of capability to produce antibodies, including antibodies • Production of antibodies facilitate optimal CD4+ T-cell • Also negatively regulate the immune response by producing regulatory cytokines and directly interacting with pathogenic T cells via cell-to-cell contact

  26. 3 signals are needed in order for an Antigen Presenting Cells (APCs) to stimulate a naïve T cells: 1. Antigen Specific Signal: MHC Class II + TCR 2. Co-stimulatory Signal: B7 + CD28 3. Differentiation Signal: APC secretes a variety of cytokines promoting different effector T cell outcomes An absence of the antigen-specific signal will lead to anergic or clonally deleted T cells Types of Effector T-Cells Cytotoxic T cells (Tc/CD8): kills infected cells Helper T cells (Th/CD4): Th1, Th2, Th17- activates other immune cells ie. Naïve B Cells Treg:regulates immune response B Cells Naïve B cells are activated via T Cell independent or dependent route. Independent: pathogen phagocytosis using BCR, non-isotype switching antibody production Dependent:linked recognition: phagocytosis; display on MHC Class 2, interact with Th Cell which presents (CD40) Ligand and B Lymphoctyte stimulator (BLyS) Activated B Cells Plasma Cells: migrate to cite of infection and secrete antibodies Memory B Cells- assist in future response to the same antigen Regulatory B Cells- Secrete cytokines to regulate immune responses Antibody Isotype Switching 2 variable regions, light(VL) and heavy(VH) Primarily IgM, highest levels in serum IgG. Th Cell CD40L is necessary for Ig splicing and isotype switching to occur Antibodies can: opsonize pathogens, neutralize toxins, limit viral infectivity, activate complement pathway Summary slide

  27. References • Janeway et al. (2001), Immunobiology: Garland Publishing, New York • Neuberger, M. S.; Honjo, T.; Alt, Frederick W. (2004). Molecular biology of B cells. Amsterdam: Elsevier. pp. 189–191. ISBN 0-12-053641-2. • Lang ML (Aug 2009). "How do natural killer T cells help B cells?". Expert Rev Vaccines 8 (8): 1109–21. doi:10.1586/erv.09.56. PMC 2747240.PMID 19627191. • Martin F, Kearney JF. Marginal-zone B cells. Nat Rev Immunol. 2002;2(5):323–335. • Neuberger, M. S.; Honjo, T.; Alt, Frederick W. (2004). Molecular biology of B cells. Amsterdam: Elsevier. pp. 189–191. ISBN 0-12-053641-2. • Lang ML (Aug 2009). "How do natural killer T cells help B cells?". Expert Rev Vaccines 8 (8): 1109–21. doi:10.1586/erv.09.56. PMC 2747240.PMID 19627191. • Martin F, Kearney JF. Marginal-zone B cells. Nat Rev Immunol. 2002;2(5):323–335.

More Related