MS and Autoimmunity

MS disease activity is believed to have an autoimmune component.1 Autoimmunity involves the loss of normal homeostasis and a failure in recognition of “self,” such that an abnormal immune response is mounted against self-tissue.2

The characteristics of autoimmunity include2,3:

  • Self reactive B and T cells image

    Self-Reactive B and T Cells

  • Auto antibodies image filename

    Auto-Antibodies

  • MS Inflammation image

    Inflammation

Normal immunity requires a clear connection between the innate and adaptive response.
The distinction between the body’s cells and unwanted pathogens becomes muddled in autoimmunity.4

Innate and Adaptive Immunity

Innate and adaptive immunity work together to protect the body against pathogens.4 Normal, healthy immunity requires cooperation between the innate and adaptive response.2

About Innate Immunity

About Adaptive Immunity

Innate immunity represents the first line of defense against intruding pathogens.2 It plays an important role in controlling infections before the adaptive immune response takes effect.2 Numerous cells engulf or phagocytose microbes and are involved in the innate immune response, including2:

  • Dendritic cells
  • Macrophages
  • Neutrophils

Dendritic cells and macrophages also function as antigen-presenting cells (APCs) to T cells. Dendritic cells act as messengers between innate and adaptive immunity.2

The Complement System

The complement system is a functional bridge between the innate and adaptive immune responses that allows an integrated host defense against pathogenic challenges.5 It has been shown to play a role in both B- and T-cell responses at the organismal level.5

Adaptive immunity functions include the recognition of foreign antigens in the presence of "self" antigens along with the generation of pathogen-specific immunologic response.5

Adaptive immunity also plays a role in immunologic memory, which enables a more rapid and efficient immune response upon subsequent exposure to an antigen.2

About B Cells

B cells are largely classified by their stage of maturation.2,4

Memory B cells have a long life span and can “remember” a pathogen and respond to it by creating cloned, short-lived plasma cells and activated B cells.6,7

  • Immature B Cells image

    IMMATURE B CELLS

    Immature B cells are produced in the bone marrow, migrate to secondary lymphoid structures, and then may develop into mature B cells.2,7

  • Mature B Cells image

    MATURE B CELLS

    Activated and mature B cells continue to circulate through the peripheral blood and tissues in response to specific antigens.2,6,7

  • Plasma Cells image

    PLASMA CELLS

    B cells can multiply and further mature into either plasma cells or memory B cells.7

  • Immature B Cells image

    IMMATURE B CELLS

    Immature B cells are produced in the bone marrow, migrate to secondary lymphoid structures, and then may develop into mature B cells.2,7

  • Mature B Cells image

    MATURE B CELLS

    Activated and mature B cells continue to circulate through the peripheral blood and tissues in response to specific antigens.2,6,7

  • Plasma Cells image

    PLASMA CELLS

    B cells can multiply and further mature into either plasma cells or memory B cells.7


About T Cells

T cells are classified by function and maturation.2,4

Mature T cells travel through the circulatory system until they are activated by antigen-presenting cells (APCs), including B cells.2 When stimulated by APCs, the T cell recognizes the foreign antigen and is activated to complete its specific function.2

  • T Helper Cells image

    T HELPER CELLS

    T helper cells establish and maximize the immune response through release of signals that enhance and mediate the activities of other cells.2

  • Effector T Cells Image

    EFFECTOR T CELLS

    Effector T cells are primarily involved in the destruction of cells presenting as foreign antigens.2

  • T Regulatory Cells image

    T REGULATORY CELLS

    T regulatory cells suppress activation of the immune system and help to maintain immune homeostasis.2

  • T Helper Cells image

    T HELPER CELLS

    T helper cells establish and maximize the immune response through release of signals that enhance and mediate the activities of other cells.2

  • Effector T Cells Image

    EFFECTOR T CELLS

    Effector T cells are primarily involved in the destruction of cells presenting as foreign antigens.2

  • T Regulatory Cells image

    T REGULATORY CELLS

    T regulatory cells suppress activation of the immune system and help to maintain immune homeostasis.2

Macrophages and Microglia

Macrophage precursors migrate into tissues in response to pathogens.6

About Macrophages

The functions of macrophages include engulfing or phagocytosing microbes.6 They are long-lived cells that are also involved in antigen presentation to T cells.2,4,6

About Microglia

Microglia are a type of resident macrophage.6 These are small, migratory interstitial cells that form part of the central nervous system.6,8

REFERENCES
1.
Pender MP, Greer JM. Immunology of multiple sclerosis. Curr Allergy Asthma Rep. 2007;7:285-292.
2.
Warrington R, Watson W, Kim HL, et al. An introduction to immunology and Immunopathology. Aller Asth Clin Immunol. 2011;7(Suppl 1):S1-S8.
3.
Yang M, Rui K, Wang S, et al. Regulatory B cells in autoimmune diseases. Cell Mol Immunol. 2013;10:122-132.
4.
Chaplin DD. Overview of the immune response. J Allergy Clin Immunol. 2010;125(2)(suppl 2):S3-S23.
5.
Dunkelberger JR, Song WC. Complement and its role in innate and adaptive immune responses. Cell Research. 2010;20:34-50.
6.
Owen JA, Punt J, Stranford SA, Jones PP. Kuby Immunology. 7th ed. New York, NY: WH Freeman and Company; 2013.
7.
Kalia V, Sarkar S, Gourley TS, Rouse BT, Ahmed R. Differentiation of memory B and T cells. Curr Opin Immunol. 2006;18:255-264.
8.
Hof PR, Nimchinsky EA, Kidd G, Claudio L, Trapp BD. Cellular components of nerve tissue. In: From Molecules to Networks. 2009;(2nd ed);1-17.