Transient low-dose methotrexate generates B regulatory cells that mediate antigen-specific tolerance to alglucosidase alfa.

Biologic drugs, including enzyme-replacement therapies, can elicit anti-drug Abs (ADA) that may interfere with drug efficacy and impact patient safety. In an effort to control ADA, we focused on identifying regimens of immune tolerance induction that may be readily available for clinical use. Data generated in both wild-type mice and a Pompe disease mouse model demonstrate that single-cycle, low-dose methotrexate can be as effective as three cycles of methotrexate in providing a long-lived reduction in alglucosidase alfa-specific ADA.

Transient low-dose methotrexate induces tolerance to murine anti-thymocyte globulin and together they promote long-term allograft survival.

Rabbit anti-thymocyte globulin (Thymoglobulin) effectively treats transplant rejection but induces anti-rabbit Ab responses, which limits routine readministration. Aiming to tolerize anti-rabbit responses, we coadministered a brief methotrexate regimen with a murine version of Thymoglobulin (mATG) for effects on anti-mATG Abs and cardiac allotransplantation in mice. Although both single and three courses of methotrexate could significantly inhibit anti-drug Ab titers to repeated mATG treatment, surprisingly, the single course given at the first mATG administration was most effective (>99% reduction).

A method for clonal analysis of epidermal growth factor-responsive neural progenitors.

Epidermal growth factor (EGF) responsive neural progenitors are defined by clonal growth from single cells. In previous studies we were unable to obtain clones at single cell densities using trypsinized cells and trituration alone always gave cellular aggregates. Here we report on single cell derived clones using a technique involving trituration of EGF responsive neurospheres, cell filtration, and single cell sorting using a MoFlo high speed fluorescence activated cell sorter.