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

IL-2 (CD122-Directed) Provides Increased and Sustained CD4+/CD8+ T Cell Proliferation in Side-by-Side Testing with the Standard IL-2 Protein

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 3.6 or 14.3 ng/mL 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.

T Cells Expanded with the IL-2 (CD122-Directed) Protein Display Enhanced Expression of Naive Phenotypic Markers and Reduced Expression of T Cell Exhaustion Markers Compared to T Cells Expanded with 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 14.3 ng/mL. 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.

Affinity Measurements and Binding Kinetics of the Interaction between IL-2 R beta and the IL-2 (CD122-Directed) Protein by SPR

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 K_d=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 K_d=544 nm.