IL-8/CXCL8 Protein, Human (72a.a)

Interleukin-8 (IL-8), also known as CXCL8 or NAP-1, is a pro-inflammatory CXC chemokine. IL-8 acts on human neutrophils via two receptors, CXCR1 and CXCR2. IL-8 has a conserved Glu-Leu-Arg (ELR) N-terminal motif, and is an agonist for CXCR1/CXCR2. IL-8 is produced by various cells including leukocytes, endothelial cells, and epithelial cells^[1][2][3]. IL-8/CXCL8 Protein, Human (72a.a) is produced in E.coil, and consists of 72 amino acids (S28-S99).

IL-8 (CXCL8) belongs to the ELR⁺ CXC chemokines family. IL-8 is initially produced as a protein of 99 amino acids that undergoes cleavage to form active IL-8 isoforms, a 77 amino acid peptide in non-immune cells or a 72 amino acid peptide in monocytes and macrophages. The gene encoding IL-8 is located on chromosome 4q13-q21. Dimerisation of IL-8 forms the structural basis for receptor binding. IL-8 is expressed by various cells including monocytes, macrophages, leukocytes, endothelial cells, and epithelial cells^[1][2][3].
Mature human IL-8/CXCL8 shares 75% amino acid sequence identity with canine IL-8/CXCL8. While, human IL-8 shares 94.95% aa sequence identity with Rhesus Macaque IL-8 protein.
IL-8 is responsible for the recruitment and activation of neutrophils and granulocytes to the site of inflammation. IL-8 is almost undetectable in physiological states, but is rapidly induced by pro-inflammatory cytokines such as TNFα and IL-1β. The function of IL-8 mainly relies on its interaction with specific cell surface GPCR, CXCR1 and CXCR2. In addition, IL-8 is reported to promote integrin β3 upregulation and the invasion of hepatocellular carcinoma cells through activation of the PI3K/Akt pathway. In odontogenic lesions, IL-8 has been proven to be highly expressed in ameloblastoma epithelial cells and irreversible pulpitis. In rheumatoid arthritis and other inflammatory joint diseases IL-8 could bring about the accumulation of neutrophils, which are considered a major source of cartilage-degrading enzymes. IL-8 stimulates the MAPK and tyrosine phosphorylation of cellular proteins. Tumour cells and fibroblasts communicate with each other, including autocrine and paracrine factors, including IL-8, resulting in the upregulation of MMP2 and MMP9 degradable extracellular matrix (ECM) components that trigger tumour invasion^[1][2][3][4].
  IL-8 is typically known to promote angiogenesis, but it also activates matrix metalloproteinase (MMP) that is involved in metastasisrelated tissue remodelling. IL-8 is induced in lipopolysaccharide (LPS)-stimulated monocytes and shown to induce neutrophil migration. IL-8 exerts multiple effects on biological activities of tumour cells including proliferation, invasion and migration. IL-8 also increases the expression of Akt in androgen-independent prostate cancer (AIPC) cell lines. IL-8 activates MAPK signalling via PI3K in neutrophils, and via transactivation of EGFR resulting in Ras-GTPase activation in ovarian and lung cancer cell lines. There is substantial amount of experimental data suggesting that IL-8 and receptors contribute to elimination of pathogens, but may also contribute significantly to disease-associated processes, including tissue injury, fibrosis, angiogenesis and tumorigenesis^[3][5].

Recombinant human IL-8 (10, 30, and 100 μg/kg; single intravenous injection) injected into rhesus monkeys (2-3 years; 2.5-4.5 kg). IL-8 injection results in instant neutropenia that was due to pulmonary sequestration. Within 30 minutes after IL-8 injection, neutrophilia developed with counts up to 10-fold greater than baseline levels. The numbers of hematopoietic progenitor cells (HPCs) increased of blood at 30 minutes after injection of 100 μg/kg IL-8^[7].

Recombinant human IL-8/CXCL8 (100 ng/mL; for 24-96 h) stimulation leads to enhancement of invasion and suppression of late stage apoptosis in MG-63 cells. Moreover, secretions of MMPs by MG-63 cells are also increased upon stimulation. CXCL8 induces the elevations of phosphorylated PI3K and Akt, but not PKC or FAK^[6].

The ED₅₀ is <20 ng/mL as measured by CHO cells transfected with human CXCR1, corresponding to a specific activity of >5 × 10⁴ units/mg.

Human

E. coli

Tag Free

P10145 (S28-S99)

3576  [NCBI]

SAKELRCQCIKTYSKPFHPKFIKELRVIESGPHCANTEIIVKLSDGRELCLDPKENWVQRVVEKFLKRAENS

Approximately 8.4 kDa

Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized after extensive dialysis against PBS.

<0.2 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. M Baggiolini, et al. Neutrophil-activating peptide-1/interleukin 8, a novel cytokine that activates neutrophils. J Clin Invest. 1989 Oct;84(4):1045-9.  [Content Brief]

  [2]. Baggiolini M, et al. Neutrophil-activating peptide-1/interleukin 8, a novel cytokine that activates neutrophils. J Clin Invest. 1989 Oct;84(4):1045-9.  [Content Brief]

  [3]. M Wolf, et al. Granulocyte chemotactic protein 2 acts via both IL-8 receptors, CXCR1 and CXCR2. Eur J Immunol. 1998 Jan;28(1):164-70.  [Content Brief]

  [4]. Koch AE, et al. Interleukin-8 as a macrophage-derived mediator of angiogenesis. Science. 1992 Dec 11;258(5089):1798-801.  [Content Brief]

  [5]. Qian Liu, et al. The CXCL8-CXCR1/2 pathways in cancer. Cytokine Growth Factor Rev. 2016 Oct;31:61-71.  [Content Brief]

  [6]. Jian-Feng Liu, et al. IL-8 Is Upregulated in the Tissue-Derived EVs of Odontogenic Keratocysts. Biomed Res Int. 2022 Jul 30;2022:9453270.  [Content Brief]

  [7]. Remo C Russo, et al. The CXCL8/IL-8 chemokine family and its receptors in inflammatory diseases. Expert Rev Clin Immunol. 2014 May;10(5):593-619.  [Content Brief]

  [8]. Hai Jiang, et al. CXCL8 promotes the invasion of human osteosarcoma cells by regulation of PI3K/Akt signaling pathway. APMIS. 2017 Sep;125(9):773-780.  [Content Brief]

  [9]. L Laterveer, et al. Rapid mobilization of hematopoietic progenitor cells in rhesus monkeys by a single intravenous injection of interleukin-8. Blood. 1996 Jan 15;87(2):781-8.  [Content Brief]