Cross talk between cancer and immune cells: exploring complex dynamics in a microfluidic environment

Abstract

The reconstitution of a complex microenvironment on microfluidic chips is one of the cornerstones to demonstrate the improved flexibility of these devices with respect to macroscale in vitro approaches. In this work, we realised an on-chip model to investigate the interactions between cancer and immune system. To this end, we exploited mice deficient (Knock Out, KO) for interferon regulatory factor 8 (IRF-8), a transcription factor essential for the induction of competent immune responses, to investigate how IRF-8 gene expression contributes to regulate immune and melanoma cells crosstalk. In vivo, IRF-8 KO mice are highly permissive to B16 melanoma growth due to failure of immune cells to properly exert immunosurveillance. B16 cells and immune cells isolated from the spleen of wild type (WT) and IRF-8 KO mice were co-cultured for one week in a PDMS platform and monitored by fluorescence microscopy and time-lapse recordings. We observed that WT spleen cells migrated through microchannels connecting the culturing chambers towards B16 cells and tightly interacted with tumor cells, forming clusters of activation. In contrast, IRF-8 KO immune cells poorly interacted with melanoma cells. In parallel, B16 cells were more attracted towards microchannels, acquiring a more invasive behaviour in the presence of IRF-8 KO spleen cells, with respect to WT cells. Our results strongly confirm the in vivo observations and highlight the value of on-chip co-culture systems as a useful in vitro tool to elucidate the reciprocal interactions between cancer cells and host immune system, with relevant impact in the development of more effective anti-tumor therapeutic strategies.

A multidisciplinary study usingin vivotumor models and microfluidic cell-on-chip approach to explore the cross-talk between cancer and immune cells

“…The microfluidic co-culture platforms were fabricated in PDMS (polydimethyl siloxane; Silgard 184; Dow Chemical, Detroit, MI), a bio-compatible optically transparent silicone elastomer, using standard soft lithographic techniques. Details of the fabrication protocols of these systems were described previously (Businaro et al, 2013). Access reservoirs were created using a suite of 8-mm dermal biopsy punch tools (Kai Medical, Honolulu, HI) and the final molded PDMS bonded to a glass microscope slide.…”

“…Extravasation analyses were performed using ImageJ software (http://rsbweb.nih.gov.ij/). Briefly, an ROI plug-in was used to measure the maximum distance reached by the tumor cells (with respect to microchannel borders) inside the splenocyte chamber (Businaro et al, 2013).…”

Microfluidics in Malignant Glioma Research and Precision Medicine

“…[171] Preclinical testing currently relies on animal models before human studies, which are expensive and time consuming, and lack direct application to human physiology. [172] Recent studies incorporating microfluidics into the study of immune–tumor cell interactions have revealed the need for studying several cell types at the same time to evaluate the physiologically relevant interplay during the metastatic cascade, as the immune system dynamic changes over the course of tumor progression [172,173] (Figure 11).…”

Indirect Carcinoma-stromal Interaction Enhances Invasion of Both Fibroblast and Tumor Cells on a Microfluidic Co-culture Device

“…But physical removal of the cell monolayer could damage the cells, and thus could affect the detected result of cell migration. Businaro et al realized an on-chip model consisted of two center end-closed channels to investigate interactions between cancer and immune system (Businaro et al, 2013). This model elucidated the reciprocal interactions between heterogeneous but was difficult to process.…”