4NN5, 4NN6, 4NN78548053603ENSG00000145777ENSMUSG00000024379Q969D9Q9JIE6NM_033035NM_138551NM_021367NP_149024NP_612561NP_067342Thymic stromal lymphopoietin (TSLP) is an interleukin (IL)-2-like cytokine, alarmin, and growth factor involved in numerous physiological and pathological processes, primarily those of the immune system.

TSLP mRNA expression is upregulated by certain Toll-like receptor (TLR) ligands such as flagellin and poly(I:C), but not by lipopolysaccharide (LPS) or macrophage-activating lipopeptide 2 (MALP-2).

[11] As the name suggests, TSLP was initially discovered as a growth factor derived from the supernatant of a mouse thymic stromal cell line that was found to promote the survival and proliferation of B lymphocytes.

[14] Similarly, sfTSLP reduces the severity of dextran sulphate sodium (DSS)-induced colitis in mice, a model of inflammatory bowel disease (IBD), and prevents endotoxic shock and sepsis resulting from bacterial infections.

[15] TSLP's pivotal role in initiating immune responses begins with its release by epithelial or stromal cells of the lungs, skin, or gastrointestinal tract as an alarmin following mechanical cell injury, pattern recognition receptor (PRR) and protease-activated receptor (PAR) activation, stimulation by certain cytokines, chemical irritation, or infection.

[18] As mentioned, TSLP serves as an alarmin following TLR binding by certain pathogen-associated molecular patterns (PAMPs), including viral and bacterial ones, rather than just irritation by allergens.

TSLP also holds considerable promise as a novel vaccine adjuvant and anti-cancer immunotherapy due to its broad and potent alarmin functionality, as is evidenced by numerous animal studies.

[citation needed] The TH2 cells then release factors promoting an inflammatory reaction following the repeated contact with a specific antigen in the airways.

[22] Additional approaches towards TSLP/TSLPR inhibition include peptides derived from the TSLP:TSLPR interface,[32] natural products [33] and computational fragment-based screening.