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🦠microbiology review

TNF-α

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

TNF-α, or Tumor Necrosis Factor-alpha, is a pro-inflammatory cytokine produced primarily by activated macrophages and other immune cells. It plays a crucial role in the regulation of immune responses, inflammation, and cell death.

5 Must Know Facts For Your Next Test

  1. TNF-α is a key mediator of the inflammatory response, triggering the production of other pro-inflammatory cytokines and chemokines.
  2. In the context of Major Histocompatibility Complexes and Antigen-Presenting Cells, TNF-α enhances the expression of MHC class I and II molecules, promoting the presentation of antigens to T cells.
  3. TNF-α plays a role in the activation and differentiation of B cells, which is important for Polyclonal and Monoclonal Antibody Production.
  4. Excessive or dysregulated production of TNF-α has been implicated in the pathogenesis of various inflammatory and autoimmune diseases.
  5. Therapeutic targeting of TNF-α, using monoclonal antibodies or receptor antagonists, has proven effective in the treatment of conditions such as rheumatoid arthritis, Crohn's disease, and psoriasis.

Review Questions

  • Explain the role of TNF-α in the activation and function of antigen-presenting cells.
    • TNF-α is a key cytokine that enhances the expression of MHC class I and II molecules on the surface of antigen-presenting cells, such as macrophages and dendritic cells. This increased expression of MHC molecules allows for more efficient presentation of foreign antigens to T cells, triggering their activation and the subsequent adaptive immune response. Additionally, TNF-α promotes the maturation and migration of antigen-presenting cells to secondary lymphoid organs, where they can interact with and activate T cells.
  • Describe the involvement of TNF-α in the production of polyclonal and monoclonal antibodies.
    • TNF-α plays a crucial role in the activation and differentiation of B cells, which is essential for the production of both polyclonal and monoclonal antibodies. The binding of TNF-α to its receptors on B cells can stimulate their proliferation and induce class switching, leading to the production of different antibody isotypes. Additionally, TNF-α can enhance the survival and antibody secretion of plasma B cells, which are the effector cells responsible for antibody production. This cytokine-mediated regulation of B cell function is a key component in the humoral immune response and the generation of diverse antibody repertoires.
  • Analyze the potential therapeutic targeting of TNF-α in the treatment of inflammatory and autoimmune diseases.
    • The dysregulation of TNF-α production and signaling has been implicated in the pathogenesis of various inflammatory and autoimmune diseases, such as rheumatoid arthritis, Crohn's disease, and psoriasis. Therapeutic strategies that target TNF-α, either by blocking its interaction with receptors or by neutralizing the cytokine itself using monoclonal antibodies, have proven effective in reducing inflammation and improving clinical outcomes in these conditions. By inhibiting the pro-inflammatory effects of TNF-α, these therapies can help restore immune homeostasis and alleviate the symptoms associated with excessive or inappropriate immune responses. The success of TNF-α-targeted therapies highlights the importance of this cytokine in the regulation of the immune system and the potential for its modulation in the management of immune-mediated disorders.