**Acknowledgements**

*Cells of the Immune System*

of not only the primary tumor but metastatic sites as well could be achieved thus improving long-term survival. Of note, similarly to our use of the tolerogenic TA1 in NOD mice (**Figures 4** and **5**), IA1 could be directly injected into the recipient yield-

*Schematic presentation of use and efficacy of the IA1 secretome therapeutic. Left panels: the enhanced efficacy of treated PBMC is supported by photomicrographs of allogenic PBMC responding to HeLa cells. As shown, after 72 hours incubation, resting (weak responders; left) PBMC show limited interaction when overlaid on HeLa cells. In contrast, the same PBMC, when treated for 24 hours with IA1, show a robust enhanced interaction (right) with the HeLa cell monolayer. Moreover, when IA1-treated PBMC are overlaid on SH-4 melanoma cells a greatly enhanced anti-cancer effect is noted relative to untreated PBMC. Shown are the growth profiles (as measured by electrical impedance) of SH-4 treated with either the SYN (derived from the secretome of resting PBMC) or IA1therapeutics. PBMC:SH-4 ratios included 50:1, 25:1 and 10:1. Right panels: bioreactor production of IA1 secretome is readily accomplished using an allogeneic MLR. Potential source materials include PBMC donors (A and B), autologous cells (dotted arrow), lymphocytic cell lines, or leukoreduction filters from blood collection bags. The secretome is collected at day 5 for processing into IA1 (Figure 4). IA1 is stable for months when aliquoted and frozen. Weak to absent immune response to both the primary tumor and metastatic sites allows for cancer progression. PBMC (D) from the patient can be treated* ex vivo *for 24 hours with IA1 and then reinfused into the individual where they show enhanced recognition and killing of the primary tumor and,* 

The immunomodulation of the endogenous immune system has become a major focus in treating a broad range of clinical conditions ranging from tissue/ organ engraftment, autoimmune disease and cancer therapy. While significant clinical advancements have been made in immunotherapy, substantial challenges remain. One target of interest is the biologic/clinical desire to induce a persistent systemic immunological reset that could reduce both the need for chronic therapy and reduce the potential toxicities associated with current immunomodulatory approaches. Recent studies have demonstrated that miRNA are key regulators of cellular processes involved in both tolerogenic and proinflammatory immune responses and mediate immune cell proliferation and differentiation. Using an alloresponse bioreactor secretome system we have demonstrated that miRNA-based therapeutics can be reproducibly manufactured that can systemically reorient the immune system to either a tolerogenic or proinflammatory state by simultaneously

ing a systemic proinflammatory reset of the immune system [40].

*potentially, improved immune surveillance at metastatic sites. Derived from Ref. [43].*

**82**

**7. Conclusions**

**Figure 6.**

This work was supported by grants from the Canadian Institutes of Health Research (Grant no. 123317; MDS), Canadian Blood Services (MDS) and Health Canada (MDS). The views expressed herein do not necessarily represent the view of the federal government of Canada. We thank the Canada Foundation for Innovation and the Michael Smith Foundation for Health Research for infrastructure funding at the University of British Columbia Centre for Blood Research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
