Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 23 views

    Parham Ch. 1: An Overview of The Immune System: (Fig. 1.3) Pathogen An Organism That Causes Disease Eg: Bacteria

    Uploaded by

    Abhishek Isaac Mathew
    This document provides an overview of the immune system, summarizing its primary barriers, components of innate immunity like macrophages and complement proteins, and adaptive immunity involving lymphocytes. It describes the roles of leukocytes such as B cells, T cells, NK cells, granulocytes, macrophages, dendritic cells and mast cells. It also outlines the lymphoid tissues including primary organs like bone marrow and thymus, secondary tissues like lymph nodes and spleen, and mucosa-associated lymphoid tissue.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Parham Ch. 1: An Overview of The Immune System: (Fig. 1.3) Pathogen An Organism That Causes Disease Eg: Bacteria

    Uploaded by

    Abhishek Isaac Mathew
    23 views10 pages
    This document provides an overview of the immune system, summarizing its primary barriers, components of innate immunity like macrophages and complement proteins, and adaptive immunity involving lymphocytes. It describes the roles of leukocytes such as B cells, T cells, NK cells, granulocytes, macrophages, dendritic cells and mast cells. It also outlines the lymphoid tissues including primary organs like bone marrow and thymus, secondary tissues like lymph nodes and spleen, and mucosa-associated lymphoid tissue.

    Original Description:

    1

    Original Title

    Chapter_1_BW_(1)

    Copyright

    © © All Rights Reserved

    Available Formats

    PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    This document provides an overview of the immune system, summarizing its primary barriers, components of innate immunity like macrophages and complement proteins, and adaptive immunity involving lymphocytes. It describes the roles of leukocytes such as B cells, T cells, NK cells, granulocytes, macrophages, dendritic cells and mast cells. It also outlines the lymphoid tissues including primary organs like bone marrow and thymus, secondary tissues like lymph nodes and spleen, and mucosa-associated lymphoid tissue.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    23 views10 pages

    Parham Ch. 1: An Overview of The Immune System: (Fig. 1.3) Pathogen An Organism That Causes Disease Eg: Bacteria

    Uploaded by

    Abhishek Isaac Mathew
    This document provides an overview of the immune system, summarizing its primary barriers, components of innate immunity like macrophages and complement proteins, and adaptive immunity involving lymphocytes. It describes the roles of leukocytes such as B cells, T cells, NK cells, granulocytes, macrophages, dendritic cells and mast cells. It also outlines the lymphoid tissues including primary organs like bone marrow and thymus, secondary tissues like lymph nodes and spleen, and mucosa-associated lymphoid tissue.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 10

    2013-01-08

    Parham Ch. 1: An overview of the immune system


    Introduction:
    Us vs. them: pathogens
    (Fig. 1.3)
    pathogen = an organism
    that causes disease
    eg:

    Bacteria
    Viruses
    Fungi
    Parasites
    (unicellular protozoa,
    multicellular
    invertebrates)

    Us vs. us: cancer


    cancer: unregulated / ill-regulated
    cell growth
    Macrophages and Natural Killer cells
    have roles in combating malignant cells

    1o (primary) barriers to infection


    skin: numerous layers of keratinized cells
    form a strong barrier to invading microorganisms
    mucosal membranes (mucosa):
    continuous
    with the skin
    line respiratory,
    gastrointestinal
    and urogenital
    tracts
    secrete mucous

    2013-01-08

    1o (primary) barriers to infection

    Innate immunity
    innate = not acquired i.e. present at birth
    recognizes certain classes of molecules but not
    specific organisms
    rapid response, but constant (does not vary)
    provides no memory of the pathogen

    Innate immunity

    The complement protein system is used in


    innate immunity to attack bacteria

    2013-01-08

    Innate immunity
    The innate response is also responsible for
    inflammation

    Adaptive immunity
    has a delayed response (cells require stimulus for
    activation (see lectures on clonal stimulation)
    hugely variable (e.g. see antibody diversity)
    why is this a concern?
    how is this possible (given our limited
    genome size)?
    response is specific, and further tuned during
    the response itself (see somatic hypermuation)
    provides long term memory to pathogens - up
    to lifetime immunity (memory B cells)

    Compare and contrast adaptive vs. innate immunity (Fig 1.9)

    2013-01-08

    Adaptive immunity
    entails selective
    lymphocyte activation
    (Fig. 1.10)

    Adaptive immunity
    entails selective
    lymphocyte activation
    (Fig. 1.10)

    (Fig. 1.11)

    Leukocytes (white blood cells) Hematopoiesis (Fig 1.14)


    - all blood cells
    arise through the
    determination
    and differentiation
    of hematopoietic
    stem cell progeny
    - mechanisms?

    2013-01-08

    Lymphocytes Fig. 1.12


    Small lymphocytes
    B Cells - produce cell-surface immunoglobins,
    secrete soluble form after activation (antibody)
    T Cells - produce T-cell receptor

    NK Cells
    - destroy virus-infected cells
    - involved in cancer defense

    Granulocytes
    - Neutrophils - disposable (single-use)
    macrophages - engulf invaders to destroy
    them

    2013-01-08

    - Neutrophils are released from bone marrow


    as part of innate response
    - contribute to inflammation

    Granulocytes
    Eosinophils - act in parasitic infections, secrete
    granules
    Basophils (rare) act in parasite response?

    Macrophages
    - resident in tissues (derived from monocytes)
    - initiate the innate response (cytokine signaling)
    - recruit neutrophils

    2013-01-08

    Macrophages
    - resident in tissues (derived from monocytes)
    - initiate the innate response (cytokine signaling)
    - recruit neutrophils

    Macrophages act in the inflammatory response

    Dendritic Cells
    similarities with macrophages in that
    they are resident in tissues
    act as initiators of the adaptive response
    (compared to the inflammatory
    response for macrophages)
    travel from sites of infection with
    pathogens / antigens to lymphoid
    tissues

    2013-01-08

    Mast Cells
    resident in connective tissue
    carries histamine granules
    a major contributor to inflammation

    Lymphoid tissues
    1o lymphoid organs Fig 1.18
    bone marrow
    site of hematopoiesis
    B cells remain and
    mature here
    thymus
    T Cells migrate from
    bone marrow to
    thymus and mature here
    Determination? Differentiation?

    Lymphoid tissues
    2o lymphoid organs - lymphatic system and lymph nodes
    Figures 1.18 1.25
    - lymph nodes
    lymph vessels pick up excess plasma
    system has one-way valves
    excess plasma returns to vascular system
    through lymph nodes
    lymph nodes house macrophages that
    filter out pathogens (prevent sepsis)

    2013-01-08

    -lymph nodes are also sites for pathogen: lymphocyte


    interactions (adaptive immunity)

    2013-01-08

    2o lymphoid tissue: spleen


    - acts like a lymph node for the blood stream:
    filters out pathogens that gain direct entry
    into the bloodstream
    - also functions to removed damaged / spent
    erythrocytes

    Mucosa associated lymphoid tissue (MALT)


    - in the gut (GALT) - Peyers patches

    -M cells sample gut contents and deliver antigens /


    pathogens to the lymphoid tissue

    10

    You might also like