An Alphanumeric Soup of Cytokine and Cytokine Receptor Families

Cytokines Families

Cytokines are signaling molecules that play a key role in cell communication, particularly in the immune system. They can be broadly categorized into different families, and within each family, there are cytokines with both pro-inflammatory and anti- or non-inflammatory functions. Here are major cytokine families with examples:

1. Interleukins (ILs):
   • Inflammatory ILs: IL-1, IL-6, IL-8
     • See below for more about the IL-1 and IL-17 families.
   • Anti- or non-inflammatory ILs: IL-10, IL-4, IL-13
2. Tumor Necrosis Factor (TNF) Family:
   • Inflammatory: Tumor Necrosis Factor-alpha (TNF-α), TNF-beta (TNF-β)
   • Anti- or non-inflammatory: TNF Receptor 1 (TNFR1), TNF Receptor 2 (TNFR2)
3. Interferons (IFNs):
   • Inflammatory: Interferon-gamma (IFN-γ)
   • Anti- or non-inflammatory: Interferon-alpha (IFN-α), Interferon-beta (IFN-β)
4. Chemokines:
   • Inflammatory: IL-8 (also classified as a chemokine), C-C motif chemokine ligand 2 (CCL2)
   • Anti- or non-inflammatory: Chemokine (C-C motif) ligand 18 (CCL18), C-X-C motif chemokine ligand 10 (CXCL10)
5. Transforming Growth Factor-beta (TGF-β) Family:
   • Inflammatory: TGF-β can have both pro-inflammatory and anti-inflammatory effects depending on the context.
   • Anti- or non-inflammatory: TGF-β (in certain contexts), TGF-β Receptor 2 (TGFBR2)
6. Interleukin-1 (IL-1) Family:
   • Inflammatory: IL-1α, IL-1β
   • Anti- or non-inflammatory: IL-1 Receptor Antagonist (IL-1RA)
7. Interleukin-17 (IL-17) Family:
   • Inflammatory: IL-17A, IL-17F
   • Anti- or non-inflammatory: IL-17E (IL-25)

These examples highlight the diversity of cytokines and their dual roles in promoting inflammation or other immune responses. It’s important to note that the functions of these cytokines are context-dependent, and their roles may vary in different physiological or pathological conditions. Additionally, the balance between pro-inflammatory and anti-inflammatory cytokines is crucial for maintaining immune homeostasis.

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Cytokine Receptor Families

Immune receptors play a crucial role in recognizing cytokines and initiating cellular responses. Different families of immune receptors are involved in recognizing specific cytokine families. Here are the major families of immune receptors and their association with the recognition of the cytokine families mentioned above:

1. Cytokine Receptor Superfamily:
   • Recognition of ILs: Members of the cytokine receptor superfamily, such as IL receptors, play a key role in recognizing interleukins (ILs). For example, IL-1 receptors, IL-6 receptors, and IL-10 receptors are part of this superfamily.
2. Tumor Necrosis Factor Receptor (TNFR) Superfamily:
   • Recognition of TNF Family: The TNFR superfamily includes receptors that recognize tumor necrosis factor (TNF) family cytokines. For instance, TNF receptors (TNFR1 and TNFR2) are members of this superfamily.
3. Interferon Receptor Family:
   • Recognition of IFNs: Interferons (IFNs) interact with receptors belonging to the interferon receptor family. For example, interferon-gamma (IFN-γ) interacts with its specific receptor.
4. Chemokine Receptor Family:
   • Recognition of Chemokines: Chemokine receptors are involved in recognizing chemokines. For instance, IL-8 (also classified as a chemokine) interacts with chemokine receptors, such as CXCR1 and CXCR2.
5. TGF-β Receptor Family:
   • Recognition of TGF-β Family: Transforming growth factor-beta (TGF-β) family cytokines interact with receptors belonging to the TGF-β receptor family. This family includes TGF-β receptors (e.g., TGFBR1 and TGFBR2).
6. IL-1 Receptor Family:
   • Recognition of IL-1 Family: IL-1 family cytokines, such as IL-1α and IL-1β, interact with receptors belonging to the IL-1 receptor family. IL-1 receptors, including IL-1R1 and IL-1R2, are part of this family.
7. IL-17 Receptor Family:
   • Recognition of IL-17 Family: IL-17 family cytokines interact with receptors belonging to the IL-17 receptor family. For example, IL-17A and IL-17F interact with IL-17RA and IL-17RC receptors.

These immune receptor families mediate the recognition of specific cytokines, allowing for the transmission of signals and the initiation of immune responses. The binding of cytokines to their respective receptors triggers intracellular signaling cascades that regulate various cellular functions in the immune system.

Next Topic: Chemokines: Cytokines…but Different

Source: ChatGPT response prompted and edited by Joel Graff.

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