Oxime Click-crosslinked Cryogels to Quantify and Target Tumour-associated Macrophage Invasion in Hodgkin Lymphoma

Hodgkin lymphoma (HL) cancer cells account for less than 5% of the tumour microenvironment, yet drug screening and treatment strategies typically focus on targeting malignant cells. Tumour-associated macrophages (TAMs) are associated with poor prognosis and resistance to therapy; however, there remains an unmet need for a suitable pre-clinical model to identify macrophage-targeting therapeutics. We analyzed the HL extracellular matrix (ECM) in primary tumours and found a high abundance of hyaluronic acid, collagen, and fibronectin, which guided the design of our HL-tumour mimetic hydrogel: a cryogel comprised of gelatin, hyaluronan, and fibronectin-derived peptides crosslinked using oxime click chemistry. Primary human macrophages seeded thereon migrated to a greater depth in cryogels with greater porosity and pore size; with fibronectin-derived peptides enhancing macrophage migration. We then studied classically and alternatively activated polarized macrophages in these cryogels. While IL-4/IL-13-stimulated, alternatively-activated macrophages invaded more than IFNgamma +LPS-stimulated, pro-inflammatory macrophages, both states adopted a combination of matrix-metalloproteinase (MMP)-dependent and independent invasion mechanisms. We then studied the effect of HL co-culture on macrophage invasion and found that HL direct co-culture and HL conditioned media promoted macrophage invasion into cryogels to the same extent. HL CM-induced invasion was associated with a unique polarization phenotype and upregulation of matrix-metalloproteinase 9 (MMP9) activity. In an invasion inhibitor screen of 25 drugs, we identified 5 drug hits that significantly reduced HL TAM invasion; one of these drug hits, currently approved for treating autoimmune diseases, both decreased invasion and enhanced the percentage of M1-like, anti-neoplastic/pro-inflammatory macrophages; another has demonstrated recent success in HL clinical trials. Collectively, we have designed a platform to study TAMs in HL and 1) reveal immune effects of drugs currently under clinical investigation, 2) suggest the repurposing of approved drugs to treat HL, and 3) ultimately bridge the gap between standard 2D drug screening and complex clinical readouts.

Department dc:contributor.department

Biomedical Engineering

Year dc:date.issued

2022

Author dc:creator

• Bahlmann, Laura Christine

Advisor dc:contributor.advisor

• Shoichet, Molly S

• drug screening
• gelatin
• hyaluronan
• hydrogel
• lymphoma
• tumour-associated macrophage

Handle dc:identifier.uri

http://hdl.handle.net/1807/125633

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/125633