YILIMART - Human IL-33, research grade (25 μg)

IL-33 stands for interleukin 33. Human IL-33 is a recombinant protein optimized for use in cell culture, differentiation studies, and functional assays.

Applications

Human IL-33 can be used for a variety of applications, including:

Tʜ2 cell activation and maintenance.
Investigation of intracellular signaling of IL-1 family and apoptotic/necrotic pathways.
In vitro inhibition of osteoclast differentiation.

Background information

Interleukin 33 (IL-33) is a cytokine belonging to the IL-1 family. Similarly to other IL-1 family members, IL-33 exists in both an un-cleaved (full-length) and a cleaved form, although the proteins responsible of IL-33 maturation are still under investigation. IL-33 is expressed by several cell types including epithelial cells, endothelial cells, and fibroblasts, and binds a specific receptor, also known as IL1RL1, which is expressed on Tʜ2 cells and mast cells. Signaling via IL1RL1 involves receptor accessory protein (IL1RAP) and leads to the expression of type 2 cytokines, such as IL-4, IL-5, IL-13. Via enhancing the activation of Tʜ2 cells, mast cells, and eosinophils, IL-33 sustains the humoral response and contributes to adverse Tʜ2 reactions, such as dermatitis, asthma, and allergies. Besides its primary involvement in the immune system modulation, IL-33 is also expressed in blood epithelium and smooth muscle and plays a role in bone protection. It is unclear whether also the immature form of IL-33 could be biologically active after release, such as during necrosis. Moreover, it was suggested that the full length protein could co-localize in the nucleus and act as transcriptional factor. Recombinant Human IL-33 corresponds to the mature form of human IL-33.

Quality description

Research-grade

cytokines are suitable for a wide variety of cell culture applications. They are sterile-filtered prior to lyophilization. Generally, endotoxin levels are <0.1 ng/μg (<1 EU/μg), and purities are >95%. The biological activity is tested in appropriate bioassays.

Premium-grade

cytokines offer the convenience of high and well-defined biological activities and allow exact unit dosing for demanding applications. The biological activity is determined after lyophilization and reconstitution, and normalized to WHO/NIBSC standards whenever available. In general, endotoxin levels are <0.01 ng/μg (<0.1 EU/μg), and purities are >97%. Lot-specific certificates of analysis are available on request (macstec@miltenyibiotec.de).

Biological activity

Proliferation of D10.G4.1 cells
premium grade: ≥ 8×

10
⁵
U/mg
research grade: ≥ 4×

10
⁵
U/mg

Figure 1
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Figure 1

SDS-PAGE of Human IL-33, premium grade
under reduced (R) and non-reduced (NR) conditions.

SDS-PAGE of Human IL-33, premium grade
under reduced (R) and non-reduced (NR) conditions.
Figure 2
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Figure 2

Mass spectrometry analysis (ESI-MS) of Human IL-33, premium grade. The peak corresponds to the calculated molecular mass of 19437 Da.

Mass spectrometry analysis (ESI-MS) of Human IL-33, premium grade. The peak corresponds to the calculated molecular mass of 19437 Da.
Figure 3
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Figure 3

Human IL-33 biological activity.
Activity of Human IL-33, premium grade was determined without CD3ε pure – functional grade, mouse (clone: 145-2C11) (left bar) and co-stimulated with CD3ε pure – functional grade, mouse (clone: 145-2C11) (right bar).

Human IL-33 biological activity.
Activity of Human IL-33, premium grade was determined without CD3ε pure – functional grade, mouse (clone: 145-2C11) (left bar) and co-stimulated with CD3ε pure – functional grade, mouse (clone: 145-2C11) (right bar).
Figure 4
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Figure 4

Human IL-33 activity assay.
The biological activity of Human IL-33, premium grade was determined by proliferation assay using D10.G4.1 cells.

Human IL-33 activity assay.
The biological activity of Human IL-33, premium grade was determined by proliferation assay using D10.G4.1 cells.