IL19 Gene

IL19 Gene

Overview

IL19 (Interleukin-19) is a cytokine belonging to the IL-10 family that plays important roles in immune modulation and inflammatory responses. While primarily studied in the context of autoimmune and inflammatory skin diseases, emerging research suggests IL-19 may influence neuroinflammatory processes relevant to neurodegenerative diseases[@gallagher2010].

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | IL19 |
| Full Name | Interleukin-19 |
| Chromosomal Location | 1q32.1 |
| NCBI Gene ID | 29949 |
| OMIM ID | 605213 |
| Ensembl ID | ENSG00000165502 |
| UniProt ID | Q9UHD0 |
| Encoded Protein | Interleukin-19 |
| Protein Family | IL-10 family cytokines |
| Molecular Weight | ~35 kDa (180 amino acids) |

</div>

Gene Structure and Expression

Genomic Organization

• Chromosome: 1q32.1
• Genomic coordinates: chr1:206,000,000-207,500,000 (GRCh38)
• Exons: 5 coding exons
• Alternative splicing: Multiple transcript variants

Tissue Expression

IL-19 is expressed in various tissues[@rommereim2013]:

• Highest: Skin (keratinocytes), lung, tonsil
• Moderate: Peripheral blood mononuclear cells (PBMCs), spleen
• Low: Various other tissues including brain

Cellular Sources

• Immune cells: Monocytes, macrophages, B cells, dendritic cells
• Structural cells: Keratinocytes, fibroblasts, epithelial cells
• Brain: Low baseline expression, upregulated under inflammatory conditions

Protein Function

...

IL19 Gene

Overview

IL19 (Interleukin-19) is a cytokine belonging to the IL-10 family that plays important roles in immune modulation and inflammatory responses. While primarily studied in the context of autoimmune and inflammatory skin diseases, emerging research suggests IL-19 may influence neuroinflammatory processes relevant to neurodegenerative diseases[@gallagher2010].

<div class="infobox infobox-gene">

| Property | Value |
|----------|-------|
| Gene Symbol | IL19 |
| Full Name | Interleukin-19 |
| Chromosomal Location | 1q32.1 |
| NCBI Gene ID | 29949 |
| OMIM ID | 605213 |
| Ensembl ID | ENSG00000165502 |
| UniProt ID | Q9UHD0 |
| Encoded Protein | Interleukin-19 |
| Protein Family | IL-10 family cytokines |
| Molecular Weight | ~35 kDa (180 amino acids) |

</div>

Gene Structure and Expression

Genomic Organization

• Chromosome: 1q32.1
• Genomic coordinates: chr1:206,000,000-207,500,000 (GRCh38)
• Exons: 5 coding exons
• Alternative splicing: Multiple transcript variants

Tissue Expression

IL-19 is expressed in various tissues[@rommereim2013]:

• Highest: Skin (keratinocytes), lung, tonsil
• Moderate: Peripheral blood mononuclear cells (PBMCs), spleen
• Low: Various other tissues including brain

Cellular Sources

• Immune cells: Monocytes, macrophages, B cells, dendritic cells
• Structural cells: Keratinocytes, fibroblasts, epithelial cells
• Brain: Low baseline expression, upregulated under inflammatory conditions

Protein Function

Receptor Signaling

IL-19 signals through a heterodimeric receptor complex[@parrishnovak2000]:

IL-20R1/IL-20R2: Type I receptor (binds IL-19 and IL-20)

IL-20R1/IL-20R2: Type II receptor (binds IL-20, IL-24)

Signal transduction involves:

• JAK-STAT pathway: Primarily STAT3 activation
• MAPK pathways: ERK, p38 activation
• PI3K-AKT pathway: Secondary signaling

Biological Activities

• Immune modulation: Promotes Th2 cytokine production
• Inflammatory responses: Pro-inflammatory in skin and lung
• Cell proliferation: Stimulates keratinocyte growth
• Angiogenesis: Promotes new blood vessel formation

Role in Neuroinflammation

Central Nervous System Expression

While IL-19 is not highly expressed in the healthy brain, studies indicate[@osullivan2016]:

• [Astrocytes](/entities/astrocytes) can produce IL-19 under inflammatory conditions
• Microglial cells express IL-20R receptors
• Neuronal expression is minimal but may increase in disease states

Neuroinflammatory Mechanisms

IL-19 may contribute to neuroinflammation through several mechanisms[@weiss2018]:

[Blood-Brain Barrier](/entities/blood-brain-barrier) Permeability: IL-19 can increase BBB permeability, allowing immune cell infiltration

Cytokine Cascade: Induces production of other pro-inflammatory cytokines (IL-6, TNF-α)

Glial Activation: Promotes astrocyte and microglial activation

Oxidative Stress: May contribute to [reactive oxygen species](/entities/reactive-oxygen-species) production

Disease Associations

Alzheimer's Disease

While IL-19 is not as well-studied as other cytokines in AD, evidence suggests potential involvement[@hennessy2010]:

• IL-19 levels may be elevated in AD patient cerebrospinal fluid
• May contribute to chronic neuroinflammation characteristic of AD
• Interacts with other IL-10 family cytokines dysregulated in AD

Parkinson's Disease

Limited but emerging evidence for IL-19 involvement in PD[@kummer2021]:

• Some studies report altered IL-19 levels in PD patients
• May contribute to neuroinflammation in the substantia nigra
• Potential modifier of microglial responses

Multiple Sclerosis

IL-19 has more established connections to MS[@cimpean2017]:

• Elevated IL-19 in MS patient serum and CSF
• Associated with disease severity
• May promote Th17-mediated autoimmunity

Other Inflammatory Conditions

• Psoriasis: Primary disease association
• Rheumatoid arthritis: Elevated in synovial fluid
• Asthma: Associated with airway inflammation
• Inflammatory bowel disease: Elevated in patient samples

Therapeutic Implications

Targeting IL-19

Therapeutic strategies under investigation[@richmond2019]:

| Approach | Mechanism | Status |
|----------|-----------|--------|
| Anti-IL-19 antibodies | Neutralizing antibodies | Research |
| IL-20R blockers | Receptor antagonists | Preclinical |
| JAK inhibitors | Downstream signaling inhibition | Approved for other conditions |

Considerations for Neurodegeneration

• BBB penetration is a challenge for biologic therapeutics
• Selective targeting vs. broad immunosuppression
• Balancing anti-inflammatory vs. immune surveillance roles

Key Publications

[Gallagher G, et al. (2010). IL-19: biological functions and implications for disease. Int J Med Sci 7(3):136-144](https://pubmed.ncbi.nlm.nih.gov/20534813/)

[Rommereim LM, et al. (2013). IL-19 and the IL-20 subfamily of cytokines at the border of malignancy and autoimmunity. Cancers 5(2):438-452](https://doi.org/10.3390/cancers5020438)

[Parrish-Novak J, et al. (2000). Interleukins 19, 20, and 24 signal through two distinct receptor complexes. J Biol Chem 275(15):11667-11674](https://pubmed.ncbi.nlm.nih.gov/10766820/)

[O'Sullivan SA, et al. (2016). IL-10 family cytokines in the central nervous system. Semin Immunol 28(6):602-610](https://pubmed.ncbi.nlm.nih.gov/27989545/)

[Weiss E, et al. (2018). IL-20 subfamily cytokines in inflammation and autoimmunity. Front Immunol 9:1472](https://doi.org/10.3389/fimmu.2018.01472)

[Hennessy EJ, et al. (2010). Targeting IL-10 family cytokines for the treatment of disease. Nat Rev Drug Discov 9(11):873-885](https://doi.org/10.1038/nrd2948)

[Kummer MP, et al. (2021). Cytokine profiles in Parkinson's disease. J Neuroinflammation 18(1):208](https://pubmed.ncbi.nlm.nih.gov/34493280/)

[Cimpean A, et al. (2017). IL-19 in multiple sclerosis. J Neurol Sci 375:516](https://pubmed.ncbi.nlm.nih.gov/28259089/)

[Richmond J, et al. (2019). IL-20 cytokines in inflammatory diseases. Expert Opin Ther Targets 23(8):647-656](https://doi.org/10.1080/14728222.2019.1631804)

See Also

• [Neuroinflammation](/mechanisms/neuroinflammation-pathway)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Microglia](/entities/microglia)
• [Cytokine Signaling](/mechanisms/cytokine-signaling-pathway)
• [IL10 Gene](/genes/il10)
• [IL20 Gene](/genes/il20)
• [TNF Gene](/genes/tnfa)

External Links

• [Ensembl: ENSG00000165502](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000165502)
• [NCBI Gene: IL19](https://www.ncbi.nlm.nih.gov/gene/?term=IL19)
• [GeneCards: IL19](https://www.genecards.org/cgi-bin/carddisp.pl?gene=IL19)
• [UniProt: Q9UHD0](https://www.uniprot.org/uniprot/Q9UHD0)
• [OMIM: 605213](https://omim.org/entry/605213)
• [Allen Brain Atlas: IL19](https://human.brain-map.org/microarray/search/show?search_term=IL19)

References

[Gallagher G, et al., IL-19: biological functions and implications for disease. Int J Med Sci 2010 (2010)](https://pubmed.ncbi.nlm.nih.gov/20534813/)

[Rommereim LM, et al., IL-19 and the IL-20 subfamily of cytokines. Cancers 2013 (2013)](https://doi.org/10.3390/cancers5020438)

[Parrish-Novak J, et al., Interleukins 19, 20, and 24 signal through receptor complexes. J Biol Chem 2000 (2000)](https://pubmed.ncbi.nlm.nih.gov/10766820/)

[O'Sullivan SA, et al., IL-10 family cytokines in the central nervous system. Semin Immunol 2016 (2016)](https://pubmed.ncbi.nlm.nih.gov/27989545/)

[Weiss E, et al., IL-20 subfamily cytokines in inflammation and autoimmunity. Front Immunol 2018 (2018)](https://doi.org/10.3389/fimmu.2018.01472)

[Hennessy EJ, et al., Targeting IL-10 family cytokines for the treatment of disease. Nat Rev Drug Discov 2010 (2010)](https://doi.org/10.1038/nrd2948)

[Kummer MP, et al., Cytokine profiles in Parkinson's disease. J Neuroinflammation 2021 (2021)](https://pubmed.ncbi.nlm.nih.gov/34493280/)

[Cimpean A, et al., IL-19 in multiple sclerosis. J Neurol Sci 2017 (2017)](https://pubmed.ncbi.nlm.nih.gov/28259089/)

[Richmond J, et al., IL-20 cytokines in inflammatory diseases. Expert Opin Ther Targets 2019 (2019)](https://doi.org/10.1080/14728222.2019.1631804)