Hit-and-Run Action of Stem Cells Exploited for Targeted Drug Delivery

jack1381818

Scientists have inserted mRNA into mesenchymal stem cells (MSCs) to produce a drug-delivery vehicle. Following systemic administration, the modified MSCs targeted and adhered to sites of inflammation, then released interleukin-10 that significantly reduced local swelling.5 e7 t8 J+ `& x* E6 f8 I9 d
2 Z+ a: E- t# E& w% M5 p
Historically, MSC-based treatments have had mixed results. MSCs exert their therapeutic effects in hit-and-run style. That is, MSCs are rapidly cleared after entering the bloodstream, typically within a few hours or days. Yet, despite the transience of MSC therapeutic action, a team of scientists reports that it has engineered MSCs that rapidly localized at a distant site of inflammation in an in vivo model, and delivered therapeutically relevant concentrations of the drug. The MSCs had been engineered enhanced homing and the expression of interleukin-10, which is not inherently produced by MSCs.
2 M% B+ `6 o; @+ w. `
5 C$ D+ C4 P6 g& rThe team of scientists included members representing Brigham and Women’s Hospital, the Harvard Stem Cell Institute, MIT, and Massachusetts General Hospital. The team, which published the results of its proof-of concept study in the October 3 issue of Blood, notes that its work is already drawing interest from biopharmaceutical companies.
( ?6 L7 s! t1 n* h! w
$ Z2 y7 c6 {. _9 o  A7 X“This opens the door to thinking of mRNA transfection of cell populations as next-generation therapeutics in the clinic, as they get around some of the delivery challenges that have been encountered with biological agents,” said Oren Levy, Ph.D., co-lead author of the study and instructor of medicine in the laboratory of research leader Jeffrey Karp, Ph.D. Dr. Karp, a Harvard Stem Cell Institute principal faculty member and associate professor at the Brigham and Women's Hospital, is also affiliated with Harvard Medical School and MIT.4 W( N% f2 T; `: A/ K0 N( F1 c) S

2 k( {, e$ d0 v# Y, j6 j& E“If you think of a cell as a drug factory, what we’re doing is targeting cell-based, drug factories to damaged or diseased tissues, where the cells can produce drugs at high enough levels to have a therapeutic effect,” said Dr. Karp.
' Y3 W8 A% W$ g, X. A$ d1 r8 @: a& L
7 K* i0 P# A3 g( A2 [* SThe key to success was the use of triple-transfected MSCs. In addition to expressing interleukin-1-, the cells expressed, in the team’s words, “functional rolling machinery.” This machinery consisted of P-selectin glycoprotein ligand-1(PSGL-1) and Sialyl-Lewisx (SLeX). Basically, the cells expressed both the immunomodulating agent and adhesive surface proteins.8 y' T( I; F& t& n% Q