IL7 (Interleukin-7) <table class="infobox infobox-gene">Symbol </td>NCBI Gene ID </td>Chromosome </td>Protein Class </td>Molecular Weight </td>
Overview
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IL7 (Interleukin-7) <table class="infobox infobox-gene">Symbol </td>NCBI Gene ID </td>Chromosome </td>Protein Class </td>Molecular Weight </td>
Overview
Mermaid diagram (expand to render)
IL7 (Interleukin-7) is a critical cytokine for lymphocyte development and homeostasis. Originally discovered for its role in B and T cell development, IL-7 is now recognized as an important factor in the immune system and has emerging roles in neurobiology. In the nervous system, IL-7 is expressed in various cell types and influences neuroinflammation, neural precursor cell function, and has been implicated in neurodegenerative and psychiatric disorders["@jiang2005"][@michaelsson2016].
Gene Overview
Function IL-7 has essential functions in immune development and homeostasis:
Immune System
T cell development : Essential for T cell development in the thymus - the "T cell survival factor"[@sportes2008]Homeostasis : Critical for maintenance of naive and memory T cellsB cell development : Important for early B cell precursorsNervous System
Neural precursor cells : IL7R expressed on neural stem/progenitor cellsNeuroinflammation : Modulates inflammatory responses in CNS[Blood-brain barrier](/entities/blood-brain-barrier) : May influence BBB functionNeuropsychiatric effects : IL-7 pathways implicated in depression and schizophreniaReceptor Complex IL-7 signals through a heterodimeric receptor:
IL7Rα (IL7RA): High-affinity binding subunit (CD127)Common γ chain (IL2RG): Signal-transducing subunit (shared with IL-2, IL-4, IL-9, IL-15, IL-21)Signaling Pathways IL-7 activates multiple signaling cascades:
JAK/STAT pathway : JAK1/JAK3 and primarily STAT5, also STAT3PI3K/Akt pathway : Critical for cell survival signalsMAPK/ERK pathway : Cell proliferation and differentiationPLC-γ pathway : Additional activation signals
Disease Associations
Neurodegenerative Diseases
Alzheimer's Disease : IL-7 and IL7R genetic variants associated with AD risk; altered expression in AD brain[@huang2019]Parkinson's Disease : IL-7 may modulate neuroinflammation in PDMultiple Sclerosis : IL-7R polymorphisms associated with MS susceptibility; IL-7 drives pathogenic T cell responses[@lundmark2007]ALS : Altered IL-7 signaling in ALS modelsOther Conditions
Severe combined immunodeficiency (SCID) with T cell deficiency
HIV/AIDS (T cell depletion)
Autoimmune diseases (rheumatoid arthritis, lupus)
Cancer (certain lymphomas)
Expression IL-7 expression is primarily in stromal cells:
Therapeutic Targeting IL-7 pathway is being explored:
Recombinant IL-7 : In clinical trials for immunodeficiency and as cancer immunotherapy adjuvantIL-7R antagonists : Potential for treating autoimmune diseasesBiomarkers : IL-7 and IL7R as disease markersCross-References
[Alzheimer's Disease](/diseases/alzheimers-disease)
[Parkinson's Disease](/diseases/parkinsons-disease)
[Multiple Sclerosis](/diseases/multiple-sclerosis)
[Neuroinflammation](/mechanisms/neuroinflammation)
[JAK/STAT Pathway](/mechanisms/jak-stat-pathway)
[T cells](/cell-types/t-cells)
See Also
[Alzheimer's Disease](/diseases/alzheimers-disease)
[Parkinson's Disease](/diseases/parkinsons-disease)
[Multiple Sclerosis](/diseases/multiple-sclerosis)
[Neuroinflammation](/mechanisms/neuroinflammation)
[JAK/STAT Pathway](/mechanisms/jak-stat-pathway)
External Links
[NCBI Gene: 3564](https://www.ncbi.nlm.nih.gov/gene/3564)
Brain Atlas Resources
Allen Brain Atlas
[Allen Human Brain Atlas](https://human.brain-map.org/microarray/search/show?search_term=IL7) - Gene expression data
[Allen Mouse Brain Atlas](https://mouse.brain-map.org/) - Mouse brain gene expression
[BrainSpan Atlas](https://www.brainspan.org/) - Developmental transcriptome data
[Allen Cell Type Atlas](https://celltypes.brain-map.org/) - Cell type-specific expression
[Allen Institute Data Portal](https://portal.brain-map.org/) - Neuroscience data resources
References
[Jiang et al., IL-7 in immune system (2005) (2005)](https://doi.org/10.1038/nri1630)
[Michaelsson et al., IL-7 in CNS (2016) (2016)](https://doi.org/10.1016/j.neuropharm.2015.12.020)
[Sportes et al., IL-7 in T cell homeostasis (2008) (2008)](https://doi.org/10.1182/blood-2007-11-125203)
[Huang et al., IL-7R and Alzheimer's disease (2019) (2019)](https://doi.org/10.1038/s41598-019-46125-8)
[Lundmark et al., IL-7R in multiple sclerosis (2007) (2007)](https://doi.org/10.1038/nm1620) Show full description