Recombinant Human IL-2 (CD122-Directed) Protein, CF

CD4+ and CD8+ T cells from two different donors were activated with anti-CD3-, anti-CD28-conjugated beads, and grown for 28 days in media containing either 50 or 200 international units (IU) of Animal-free Recombinant Human IL-2 Protein (BT-002-AFL) as the standard IL-2 protein or engineered Recombinant Human IL-2 (CD122-Directed) Protein (BT-002DBR), refreshed every 2-3 days. The average fold expansion of the cells was determined every 2-3 days. The IL-2 (CD122-Directed) Protein supports greater than 6x more CD4+/CD8+ T cell growth than the standard IL-2 protein.

CD4+ and CD8+ T cells from three different donors were activated with anti-CD3-, anti-CD28-conjugated beads, and grown in media containing 50 or 200 IU of Animal-free Recombinant Human IL-2 Protein (BT-002-AFL) as the standard IL-2 protein or Recombinant Human IL-2 (CD122-Directed) Protein (BT-002DBR), refreshed every 2-3 days. A) After 28 days, the phenotypes of the cells were compared by flow cytometry using a Brilliant Violet 711™ anti-human CD197 (CCR7) antibody and PE/Dazzle™ 594 anti-human CD45RA antibody to determine the number of CD4+ and CD8+ naive (CD45RA+/CCR7+) Tscm cells. The percentage of Tscm cells was found to be higher when the cells were expanded with the IL-2 (CD122-Directed) Protein at 200 IU. B) The number of cells expressing the T cell exhaustion markers, PD-1, LAG-3, and TIM-3 was determined by flow cytometry. The results showed that the percentages of CD4+/CD8+ T cells that were also PD-1, LAG-3, or TIM-3 positive were equivalent or reduced with the IL-2 (CD122-Directed) Protein. These results demonstrate that the IL-2 (CD122-Directed) Protein promotes increased T cell expansion with enhanced expression of naive phenotype markers and equivalent or reduced expression of cell exhaustion markers.

Recombinant Human IL 2 R beta Fc Protein (10919-2B) was captured on a Sensor Chip Protein AGL, and binding to Recombinant Human IL-2 (CD122-Directed) Protein (BT-002DBR) was measured at a concentration range between 0.097nM and 200 nM. The double-referenced sensorgram was fit to a 1:1 binding model to determine the binding kinetics and affinity, with an affinity constant of Kd=49.3 nM. Note: The IL-2 (CD122-Directed) Protein was modeled to engage only the IL-2 dimeric beta gamma receptor complex. In comparison, wild type recombinant human IL-2 (BT-002) affinity to Recombinant Human IL 2 R beta Fc Chimera (10919-2B) has a binding constant Kd=544 nm.

Recombinant Human IL-2 (CD122-Directed) Protein (Catalog # BT-002DBR) stimulates proliferation of NK-92 human natural killer lymphoma cells. The ED50 for this effect is 0.0500-0.500 ng/mL.

2 μg/lane of Recombinant Human IL-2 (CD122-Directed) Protein (Catalog # BT-002DBR) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 12‑14 kDa, under reducing conditions.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human IL-2 (CD122-Directed) Protein, CF Summary

• Additional Information: AI Modified Protein
• Details of Functionality: Measured in a cell proliferation assay using NK-92 human natural killer lymphoma cells. The ED₅₀ for this effect is 0.0500-0.500 ng/mL.
• Source: E. coli-derived human IL-2 protein
  Ala21-Thr153 (C145S) with and without an N-terminal Met
  Proprietary point mutations
• Accession #: P60568.1
• N-terminal Sequence: Ala21 & Met-Ala21
• Protein/Peptide Type: Recombinant Proteins
• Endotoxin Note: <0.20 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 15 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 12-14 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in Sodium Acetate with Trehalose.
• Reconstitution Instructions: Reconstitute the 10 μg size at 100 μg/mL in water. Reconstitute all the other sizes at 500 μg/mL in water.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human IL-2 (CD122-Directed) Protein, CF

• Aldesleukin
• IL2
• IL-2
• IL-2lymphokine
• interleukin 2
• interleukin-2
• involved in regulation of T-cell clonal expansion
• Proleukin
• T cell growth factor
• T-cell growth factor
• TCGF

Background

CD122 directed IL-2 has a 7-fold increased binding affinity to the human IL-2 beta receptor while exhibiting significantly reduced affinity for the IL-2 alpha receptor. According to research by Levin (2012), this configuration results in more effective expansion of effector cells and less Treg (1). Our findings show that CD122 directed IL-2 improves immune cell expansion for workflows requiring significant amounts of IL-2. One concern with improving T cell expansion is the possibility of increasing the number of terminally differentiated and exhausted T cells with reduced anti-tumor activity. However, our studies have shown that CD122 directed IL-2 significantly improves T cell expansion without changing T cell phenotype or the expression of exhaustion markers.

1. Levin, A., Bates, D., Ring, A. et al. (2012) Nature. 484:529.

Bioinformatics

• Uniprot:
  • P60568.1()