Consequences of adjusting cell density and feed frequency on serum-free expansion of thymic regulatory T cells.

Background: Given the promising results from phase 1/2 clinical trials of therapy involving regulatory T cells (Tregs), it is critical to develop Treg manufacturing methods that use well-defined reagents.

Methods: Seeking to maximize expansion of human thymic Tregs activated with anti-CD3/CD28 antibody-coated beads and cultured in serum-free medium, the authors investigated the effect of adjusting process parameters including cell density and cell concentration, and feeding strategy on Treg yield and quality.

Results: The authors found that levels of expansion and viability varied with cell density on the day of restimulation.

Eosinophils Decrease Pulmonary Metastatic Mammary Tumor Growth.

Metastatic breast cancer is challenging to effectively treat, highlighting the need for an improved understanding of host factors that influence metastatic tumor cell colonization and growth in distant tissues. The lungs are a common site of breast cancer metastasis and are host to a population of tissue-resident eosinophils. Eosinophils are granulocytic innate immune cells known for their prominent roles in allergy and Th2 immunity.