Webinar

<Dr. Angelica Gomes Ueltschy>

Welcome, everybody, to Trailhead’s second webinar of 2025. My name is Dr. Angelica Gomes Ueltschy, Scientific Director here at Trailhead Biosystems.  

Before we begin, I would like to take a moment to let everyone know that today’s webinar is being recorded and will be available shortly on our website. All attendee microphones have been disabled for this presentation.  

We will have a short Questions and Answers session at the end of today’s presentation –you can submit your questions to our team through the chat/question submission button in your Teams navigation bar, and we will try to get through as many questions as possible within our time. If you have any questions after the live webinar is over, you can reach out directly to our team at support@TrailBio.com 

Today I have the privilege of introducing Dr. Michael Elias, our Field Applications Scientist at Trailhead Biosystems, who will be presenting today’s topic: “iPSC-Derived HPCs: Enabling Scalable and Standardized Blood Cell Production”. 

Dr. Michael Elias earned his PhD in Nanoscience from UNC Greensboro, where he focused on stem cell differentiation for cancer therapy. He is a stem cell biologist with expertise in regenerative medicine, immunology, and translational research.  

After completing postdoctoral work at the Cleveland Clinic, where he studied inflammatory diseases and fibrosis, he joined Trailhead Biosystems, where he has helped develop and scale protocols for iPSC-derived hematopoietic progenitor cells over the past 4 years.  

His work bridges cutting-edge cell biology with real-world therapeutic applications.  

Michael, thank you for presenting today. 

<Dr. Michael Elias>

Here’s a quick overview of what we’ll cover today.​

First, I’ll introduce Trailhead Biosystems and then touch on hematopoiesis as the foundation of blood development.​

Next, we’ll look at why iPSC-derived HPCs are valuable compared to donor sources.​

I’ll then walk through Trailhead’s approach, the iPSC-derived HPCs that we developed at Trailhead using our HD-DoE® platform.​

And finally, we’ll wrap up with key applications of these cells.​

Trailhead Biosystems, founded in 2015 and based in Ohio, focuses on generating specialized cells derived from the mesoderm, endoderm, and ectoderm. ​

Pictured here is our facility. We are located in Beachwood, Ohio, just outside of Cleveland. ​

Since our mission is to create specialized cells from stem cells, it’s important to highlight where the real challenges in the field lie. Many years of research have gone into reprogramming iPSCs, and we now know how to reliably bring them back to a versatile state where they can become any cell type.​

The real hurdle isn’t reprogramming, it’s guiding these iPSCs into the right specialized lineages. That’s where Trailhead comes in. Our work focuses on solving this differentiation challenge, using iPSCs as a customizable platform to generate functional, specialized cells.​

These cells can then be applied across multiple areas, from cell therapy and drug discovery to disease modeling and tissue repair.​

Let’s talk about some of the major challenges with iPSC-derived cells today.​

First, the demand for high-quality human cells is enormous, but right now the options are limited. Researchers and companies alike are eager to use these cells for therapy, disease modeling, and drug discovery — but the field continues to run into the same problems.​

Second, obtaining pure populations can be a challenge. Many of the available cells simply don’t meet the standards needed for consistent and reliable results.​

Also, there’s a lack of consistency from batch to batch. That means a researcher might get one set of results from one vial, and then something completely different from the next.​

Fourth, supply is a bottleneck. These cells just aren’t available in the quantities that the market truly demands.​

And finally, much of the development and production is still being done manually. This slows everything down and introduces opportunities for error, which makes it very difficult to scale.​

Together, these challenges create a major roadblock for the field, and solving them is the key to unlocking the full potential of iPSC-derived cells​

Now that we’ve looked at the problems, let’s move into how we solve them​

At Trailhead, our approach is to fundamentally change how stem cell discovery and manufacturing are done.​

Rather than relying on slow and traditional iterative processes, we leverage machine enablement to accelerate discovery. This allows us to test and optimize conditions at a scale that simply isn’t possible by hand.​

We also use this approach to efficiently explore the high-dimensional space of regulatory inputs: the combinations of growth factors, small molecules, and culture conditions that control cell fate. By doing this, we can fine-tune differentiation pathways in a way that drives both precision and consistency.​

The result is vastly improved cell purity and the ability to generate specialized subtypes that meet the needs of researchers and clinicians. With identified critical process parameters, these cells can then be manufactured reproducibly and at scale.​

And because this entire system is built on a flexible production platform, it can be applied to multiple cell types while remaining cost-effective. The result is broader access, more reliable results, and ultimately, real impact for patients and the field as a whole.​

So how do we actually make all of this possible? The answer is our HD-DoE platform.​

HD-DoE stands for High-Dimensional Design of Experiments, and it’s the core technology that drives everything we do at Trailhead.​

Instead of relying on trial and error, we use proprietary software tools that we’ve developed in-house to design experiments at a scale and complexity that would otherwise be difficult to achieve. These experiments are then executed using computerized, robotic systems, which means we can achieve a remarkable level of speed, precision, and scalability.​

All the data generated through these experiments is novel, giving us a unique and expanding knowledge base. And because everything is data-driven, we can determine critical process parameters in an unbiased, empirical way.​

This combination of advanced software, robotics, and data ownership is what allows us to exponentially accelerate cell protocol development and reliably generate specialized cell types.​

So here is a visual example of our HD-DoE platform. If we want to look at 12 factors and how they affect the cells, traditionally, that would require about 4100 experiments. With HD-DoE, we can compress that large resource-intensive 4100 experiments to 96, collecting the same amount of data, modeling that data, and predicting the cell fate outcome. This allows us to generate a lot of robust and reproducible protocols at an incredible pace. ​

Let’s move into the background of hematopoiesis​

To understand the foundation of blood development, we need to start with hematopoietic stem cells, or HSCs – the rare population of cells at the very top of the blood hierarchy.​

HSCs are unique because they are the only cells that can enable long-term and secondary engraftment. In other words, they don’t just reconstitute the blood system once; they can sustain blood production for a very long time. ​

They also have the ability to generate any blood lineage. From red cells and platelets to myeloid and lymphoid lineages, HSCs sit at the very top of the hematopoietic hierarchy.​

A critical property of HSCs is their self-renewal capacity. This allows them to persist and maintain the stem cell pool within the specialized environment of the bone marrow.​

However, it’s important to remember that HSCs come with significant challenges. ​

Outside the bone marrow niche, they are difficult to expand and maintain while preserving stemness. This is one of the biggest barriers in translating HSC biology into scalable therapies.​

Finally, long-term HSCs, which is the population found in the bone marrow with self-renewal capacity, can be identified by a well-defined set of surface markers, including CD34⁺, CD90⁺, CD45RA⁻, and CD38⁻.​

These markers are used in both research and clinical contexts to distinguish HSCs from progenitor populations.​

So, in conclusion, hematopoietic stem cells represent the gold standard for long-term blood formation, but they also illustrate why in vitro differentiation approaches like the ones we’ve discussed are so important. They give us tools to study, model, and eventually harness HSC biology in a way that overcomes the limitations of donor-derived material.​

Now that we’ve looked at the unique properties of HSCs, let’s look at how hematopoiesis happens during development. There are two major processes: primitive hematopoiesis and definitive hematopoiesis.​

The first hematopoietic progenitor cells (HPCs) emerge during primitive hematopoiesis, which is extra-embryonic and takes place in the yolk sac. This wave mainly generates red blood cells along with early erythroid and myeloid progenitors, providing oxygenation and temporary blood support for the growing embryo.​

Later, within the embryo itself, we see the onset of definitive hematopoiesis. This begins in the aorta–gonad–mesonephros region, or AGM, where hemogenic endothelium gives rise to the first hematopoietic stem cells, or HSCs.​

HSCs emerge into the bloodstream and migrate to the fetal liver, where they expand and mature, developing a distinct transcriptomic profile.​

As development continues, HSCs move into the bone marrow, which becomes their lifelong home. In the marrow, they stay in a quiescent state under hypoxic conditions. When the body needs new blood cells, these HSCs are activated and differentiate into the full range of hematopoietic lineages.​

So overall, hematopoiesis begins with a short-lived primitive wave in the yolk sac, but the definitive wave in the AGM is what establishes the HSCs that persist for life.​

In the embryo, the first long-term hematopoietic stem and progenitor cells, or HSPCs, arise in the AGM. Within the ventral wall of the dorsal aorta, a specialized group of endothelial cells called hemogenic endothelium develops the capacity to generate blood cells.​

During a process known as the endothelial to hematopoietic transition, these hemogenic endothelial cells begin to change identity. They maintain endothelial markers such as VE-cadherin and CDH5, while at the same time switching on hematopoietic transcription factors, including RUNX1. Along with this transcriptomic reprogramming, the cells also undergo a striking change in morphology. They round up, loosen the tight junctions that hold them in the vessel wall, and eventually detach. As they pull away from the endothelium, they bud into the aortic lumen and form what are known as intra-aortic hematopoietic clusters.​

The cells in these clusters are the newly specified progenitors. They can be identified by surface markers such as CD34 and CD43. More importantly, they gain the ability to generate multiple blood lineages.​

The AGM-derived HSPCs produced by this process are the very first cells with true long-term self-renewal and multilineage potential. These cells go on to seed other hematopoietic sites, first the fetal liver and eventually the bone marrow, where they will establish the foundation of the lifelong blood system.​

So why iPSC-derived HPCs?​

On this slide, I want to emphasize where hematopoietic progenitor cells are typically sourced from and why these sources are limiting.​

First, the three major donor sources are cord blood, bone marrow, and mobilized peripheral blood. Each of these has been critical for both research and clinical use for decades. But all of them present challenges.​

Cord blood is limited by the volume that can be collected per birth. That means the number of cells per unit is small, and there’s a lot of variability in yield and quality between different units. Even with cord blood banks, the supply is ultimately finite.​

Bone marrow is a more traditional source, but collection is invasive for donors, and it isn’t always easy to find suitable matches. The quality and expansion capacity of the cells can also vary from one donor to another.​

Mobilized peripheral blood requires treating donors with mobilizing agents to move stem and progenitor cells out of the bone marrow and into the bloodstream. Not all donors respond the same way, and the mobilization process itself adds cost, complexity, and regulatory hurdles.​

Another challenge with primary cells is donor compatibility. For allogeneic use, immune rejection and the need for HLA matching are constant concerns. For autologous use, sourcing patient-specific cells is limited and not always feasible, which restricts how broadly this approach can be applied. Finally, it is difficult to create a bank of edited cells.​

These limitations make it very hard to achieve the kind of standardization and reproducibility that modern research and industry demand.​

​Induced pluripotent stem cells address many of the shortcomings we see with donor-derived HPCs.​

First, they bring consistency. Because iPSCs can be banked and used as a starting material, differentiation runs can be repeated under controlled protocols. This minimizes lot-to-lot variability, which is a major issue when working with donor material where every lot can behave differently.​

Second, iPSCs allow for customization. You can generate lines from specific patients, or even engineer them to model a genetic disease. This opens the door to disease-specific applications. ​

Third, they provide an unlimited source of cells. Unlike cord blood or bone marrow, which are finite, iPSCs can be expanded indefinitely in culture. This ensures that the supply of HPCs is renewable and scalable to any level of demand.​

Another key benefit is reproducibility. With standardized manufacturing, iPSC-derived HPCs provide consistent populations that make data comparable across experiments, labs, and even across institutions. This is critical for advancing both research and preclinical pipelines.​

iPSCs are also scalable. They can be adapted to large-scale production systems, making them useful not only in the research lab but also in industrial platforms, high-throughput drug screening, and preclinical testing.​

Finally, the applications are broad. iPSC-derived HPCs can be used to study hematopoietic differentiation, model blood cancers, bone marrow failure syndromes, autoimmune disorders, test drugs for toxicity, and explore immunology through differentiation into downstream cell types like T cells, NK cells, or myeloid cells. In regenerative medicine, they represent a potential source for therapeutic development.​

Altogether, iPSC-derived HPCs provide a consistent, reproducible, and scalable solution to many of the barriers faced with donor-derived sources.​

​On this slide, we’re looking at donor-derived HPCs compared directly with iPSC-derived HPCs.​

For donor-derived HPCs, the biggest limitation is availability. Whether we’re talking about cord blood, bone marrow, or mobilized peripheral blood, the supply is finite and often hard to scale. There’s also high donor-to-donor variability, which makes reproducibility difficult across experiments. Collection itself can be invasive or logistically challenging, and on top of that, regulatory complexity adds further barriers. Another important point is that donor HPCs are hard to customize — you can’t easily match them to a specific disease state or patient background.​

Now, compare that with iPSC-derived HPCs. The first major advantage is supply. Once you establish a line, iPSCs represent an unlimited, renewable source of progenitors. They can be manufactured into standardized batches under controlled protocols, which improves reproducibility. Instead of invasive procedures, these cells are produced entirely in the lab, enabling scalable and controlled manufacturing. And importantly, they can be customized — whether it’s patient-specific iPSCs, disease models, or engineered controls.​

One more point to highlight is maturity. Donor-derived HPCs are naturally more mature, reflecting adult hematopoietic biology, while iPSC-derived HPCs often resemble a more fetal-like state. This is an area of active research; improving the maturation and functional capacity of iPSC-derived cells is a key step for both translational research and eventual therapeutic use.​

So in summary, while donor HPCs have been foundational, their limitations make it difficult to move the field forward. iPSC-derived HPCs offer scalability, consistency, and customization and represent the next generation of hematopoietic progenitor cell technology.​

That brings us to the next question: how do we actually recreate blood development in the lab using iPSCs?​

First, we begin with iPSCs, which at the earliest stage are pushed into mesoderm. At this stage, you see the activation of genes like Brachyury and marker KDR, which is a hallmark of primitive streak mesoderm.​

Once mesoderm is specified, WNT signaling plays an important role in guiding cells toward a hemogenic fate. Additional signals then reinforce this trajectory toward the lateral plate mesoderm, which is the developmental origin of both blood and vascular lineages.​

As the cells progress, they form what we call hematopoietic mesoderm, which can be identified by markers such as KDR and CD235a. From there, they transition into hemogenic endothelium, marked by CD34 positivity and absence of CD43. This stage is pivotal; these endothelial-like cells are sitting right on the edge of becoming blood.​

At this point, the culture conditions guide cells toward an endothelial identity, while others adopt hematopoietic fates. From there, the population can branch into two programs. ​

In the primitive program, cells differentiate into early erythroid and myeloid lineages, supporting oxygen delivery and innate immune function during early development.​

In the definitive program, cells generate multipotent progenitors that can give rise to both myeloid and lymphoid lineages, and ultimately to hematopoietic stem cells with long-term repopulating potential.​

So this figure gives us a conceptual roadmap: pluripotent stem cells, through cytokine cues, move stepwise through mesoderm, hematopoietic mesoderm, and hemogenic endothelium before splitting into primitive or definitive hematopoietic pathways.​

​Let’s move on to the trailhead approach. ​

Now that we’ve covered the biology and background of HPCs, let’s talk about how Trailhead approaches the problem of generating HPCs from iPSCs.​

We follow a three-stage workflow. Starting with pluripotent stem cells, we first induce mesoderm, then specify those cells into hemogenic endothelium, and finally guide them into hematopoietic progenitor cells.​

The most critical point in this workflow is Stage 2, the transition into hemogenic endothelium. This stage is the developmental gateway to blood, and getting it right is essential for producing functional HPCs.​

To do this, we use our proprietary HD-DoE platform. This method systematically tests and refines combinations of small molecules and proteins to fine-tune pathway activity in vitro. By controlling signaling dynamics at just the right time and dose, we can precisely direct differentiation into the hemogenic endothelium. We have screened more than 250 factors for this project.​

The outcome is a robust and reproducible process that mirrors embryonic development, but with the scalability and control required for research and translational use. This sets the stage for consistent, high-quality HPC production at Stage 3.​

​First, we confirmed mesoderm identity by immunocytochemistry, using two key markers — CD309, also known as VEGFR2, and the transcription factor Brachyury. That data isn’t shown, but it gave us confidence that mesoderm was successfully established. The next step now is to confirm progression into stage 2 – the hemogenic endothelium.​

On this slide is Stage 2, and as I mentioned earlier, it’s really the developmental gateway to blood.​

At this stage, we expose the mesodermal cells to our optimized Stage 2 media, which induces the expression of a panel of genes and markers that define hemogenic endothelium. These include RUNX1, CD31, FLI1, and CD34.​

On the slide, you can see representative ICC images showing several of these markers, for example, SOX17, CD309, RUNX1, GATA2, CD31, and CD144. This confirms their expression at the protein level.​

​We also validated this population using flow cytometry, which showed strong marker expression across the majority of cells. For example, about 82% of cells express CD31, 43% express RUNX1, and 86% express CD34. These results demonstrate that the cells are not just partially transitioning, but that we’re generating a robust and reproducible population of hemogenic endothelial cells.​

​We dove deeper and validated our stage 2 cells using bulk RNA-seq.​

On the right, you can see a heatmap of gene expression across the workflow. The genes highlighted in red are important transcription factors for hematopoiesis, including RUNX1, SOX17, GATA2, and SPI1. These are essential regulators that mark cells with hemogenic potential.​

In contrast, the genes in blue are endothelial markers, such as CDH5, PECAM1, and KDR. These confirm that the cells retain an endothelial identity.​

What’s important here is the co-expression of both gene sets. We don’t just see endothelial markers or just hemogenic markers — we see them together. That transcriptional profile is the hallmark of hemogenic endothelium, distinguishing it from the generic vascular endothelium.​

This confirmation is critical because hemogenic endothelium is the developmental gateway to blood. Once established, it sets the stage for the emergence of hematopoietic progenitor cells in Stage 3​

We dove deeper and validated our stage 2 cells using bulk RNA-seq.​

On the right, you can see a heatmap of gene expression across the workflow. The genes highlighted in red are important transcription factors for hematopoiesis, including RUNX1, SOX17, GATA2, and SPI1. These are essential regulators that mark cells with hemogenic potential.​

In contrast, the genes in blue are endothelial markers, such as CDH5, PECAM1, and KDR. These confirm that the cells retain an endothelial identity.​

What’s important here is the co-expression of both gene sets. We don’t just see endothelial markers or just hemogenic markers — we see them together. That transcriptional profile is the hallmark of hemogenic endothelium, distinguishing it from the generic vascular endothelium.​

This confirmation is critical because hemogenic endothelium is the developmental gateway to blood. Once established, it sets the stage for the emergence of hematopoietic progenitor cells in Stage 3​

Now that we’ve established the marker profile of our HPCs, let’s take a closer look at how our HD-DoE-driven TrailBio recipe compares to a standard literature-based, control recipe.​

We tested two approaches: a stage 3 control recipe, which uses commonly applied cytokine combinations, and a stage 3 TrailBio, HD-DoE–optimized recipe. The TrailBio Recipe was designed specifically to enrich for HSC signature genes, identified by Calvanese and colleagues as defining early hematopoietic stem cell identity.​

To validate this, we measured expression of these genes in our cells. The Calvanese panel includes HLF, SPINK2, HOXA9 and MECOM. ​

In Batch 1, we performed RNA sequencing, which confirmed higher expression of these genes in cells differentiated using our Trailbio recipe compared to the control. You can see this across all six genes.​

In order to confirm our data, we performed qPCR validation in a second batch of cells. Again, we saw significantly higher expression in cells generated with our recipe, confirming the enrichment of HSC-associated transcriptional programs.​

Together, these results show that the HD-DoE-driven TrailBio recipe produces cells with a stronger HSC identity compared to a cytokine stage 3 media.​

This bulk RNA-seq analysis compares our differentiated cells to the starting iPSCs. What we see is exactly what you would hope to see in properly specified progenitors: a clear loss of pluripotency markers like NANOG and SOX2, alongside strong induction of hematopoietic genes such as RUNX1, PTPRC, and SPN.​

Importantly, we also observe upregulation of HSC-associated genes, including HOPX, HOXA9, and HLF, ​

Finally, these cells turn on key transcription factors like GATA1, TAL1, and SPI1. These are the regulators that drive lineage specification into blood.​

Altogether, this profile validates that our TrailBio HPCs are not partially differentiated. They are molecularly aligned with true hematopoietic commitment.​

Here we have our product overview. ​

On the right, you can see brightfield images of the culture showing healthy, viable cells. Flow cytometry confirms that viability remains high, with recovery consistently stronger than what we see in competitor products. This is illustrated in the bar graph on the left, where TrailBio HPCs demonstrate excellent survival following thaw.​

Importantly, these cells display an HSC-like marker profile, CD34⁺, CD90⁺, CD45RA⁻, and CD38⁻-.​

Overall, what this demonstrates is that our HPCs are not only durable post-thaw but also maintain the characteristics needed for reliable research use.​

​Let’s move into the applications section​

To begin the Applications section, let’s look at one of the most widely used functional assays for hematopoietic progenitors, the colony-forming unit, or CFU, assay.​

Here, TrailBio HPCs were seeded into methylcellulose-based media and cultured for 14 days. At the end of this period, we observed the formation of multiple distinct colony types.​

On the right, you can see examples: a granulocyte colony (CFU-G), a macrophage colony (CFU-M), and an erythroid burst-forming unit (BFU-E). These represent both myeloid and erythroid lineages, demonstrating that our HPCs retain broad differentiation capacity.​

The bar graph summarizes colony counts, showing robust output across multiple lineages. ​

In summary, TrailBio HPCs not only display the expected marker profile, but they also demonstrate functional multipotency in colony-forming assays, validating their utility in downstream applications.​

​Here we are looking at the ability of TrailBio HPCs to commit to the monocyte lineage. After Stage 4 differentiation, we analyzed cells by flow cytometry, and you can see strong populations expressing monocyte markers, CD14 together with CD33. The same observation is made with CD14 and CD16. ​

In addition to these, we also looked at other markers, including CD163 and CD45. ​

The bar graph shows that TrailBio cells expressed these markers at high levels, indicating robust differentiation into monocytes.​

When compared side-by-side with a competitor’s HPCs, you’ll notice that the number of positive cells is similar across the markers shown. This data indicates that our protocol produces cells with a reliable commitment to the monocyte lineage. Additionally, we have conducted studies showing that these cells can differentiate into functional macrophages and dendritic cells.​

We found an interesting trend where our flow cytometry showed that CD14/CD33 double positivity and CD14/CD16 were on a higher proportion of our cells compared to a competitor product. We are exploring this further and welcome any comments and questions on this on our Q&A session. ​

This example highlights the functional utility of TrailBio HPCs. Not only can they generate multiple colony types in assays like CFU, but they can also be pushed into specific immune lineages like monocytes, opening the door to studying innate immune biology and related applications.​

​On this slide, I want to highlight the lineage-specific differentiation potential of our TrailBio HPCs.​

On the left side, you can see differentiation into the myeloid lineage. Our HPCs were guided through Stage 4 into myeloid progenitors and further into neutrophils at Stage 5. Flow cytometry analysis confirms the presence of a robust CD11b⁺ and CD15⁺ population. This is characteristic of a neutrophil identity.​

On the right, we have erythroid differentiation. Here, TrailBio HPCs were directed into erythroid progenitors and then into erythroid cells. This differentiation was done in the presence of dexamethasone. Flow cytometry analysis shows clear co-expression of CD71 and CD235, confirming erythroid identity.​

Together, these results demonstrate that TrailBio HPCs can be directed into multiple hematopoietic lineages, both myeloid and erythroid, providing strong functional evidence of their differentiation capacity.​

This flexibility is critical because it shows not only that the cells remain multipotent, but also that we can fine-tune their developmental trajectory for specific applications.​

​To wrap up, let me highlight a few key points.​

First, our HD-DoE platform gives us a powerful, data-driven way to guide iPSCs into committed lineages with precision and reproducibility.​

Second, our iPSC-derived HPCs are scalable, customizable, and minimize lot-to-lot variation, making them a strong alternative to donor-derived sources.​

Third, these cells retain important stemness markers like CD90, maintain a classical HSC profile, show low spontaneous differentiation, and have high post-thaw viability.​

And finally, we’ve shown their functional applications — forming myeloid and erythroid colonies, and differentiating into multiple mature blood cell types.​

This combination of innovation, quality, and functionality positions TrailBio HPCs as a reliable tool for both research and translational work.​

​Thank you for joining today’s webinar. We covered how TrailBio HPCs are generated, their robust characterization, and their applications across multiple lineages.​

For more details, you can visit our website to access product information, data sheets, blogs, and FAQs. And if you’d like to discuss specific applications or larger-scale projects, please reach out at support@trailbio.com.​

Now we will move into Q&A with my colleague Angelica, a scientific director at Trailhead who spearheaded the scientific development of these cells and is an expert in immune biology.​

With that, we would be happy to take any questions.

<Dr. Tom Allison>

Thank you, Michael, for that great presentation!  

We’ve received a few questions for the team, so let’s start with the Q&A. 

What kind of quality control or validation testing is performed on each batch? 

<Dr. Angelica Gomes Ueltschy>

Hi Tom thank you for the questions, we follow a bunch of different experiments to qualify our cells, first we measure sterility and mycoplasma to make sure our cells are clean. Second, we do a viability test by flow cytometry and stain our cells with sytox dyes to make sure that our viability is high, as you saw its around 80% on the batches of cells we have in stock. We also make sure the clients will receive the exact number that it says on the vial, approximately 1M cells / vial. Additionally, we measure markers by flow cytometry such as CD34, CD43, CD90, and CD235.  And we also do functionality studies like colony forming unit assays to make sure our cells are functional. 

<Dr. Tom Allison>

How consistent are the cells across different lots or batches? 

<Dr. Angelica Gomes Ueltschy>

Sure thank you for the question, so we have 4 batches in stock right now and measuring the consistency across these batches. We are hare happy to say that the batches are really consistent. We use Bulk RNA–seq analysis to make sure he cells have a similar profile when compared across different batches. Additionally, we do functional studies and compare the performance of the cells side by side. For instance, we measure monocyte differentiation of the cells, red blood cell differentiation, all at the same time from the different batches that we have and the cells behave really consistently in a similar range in the tests that where preformed.  

<Dr. Tom Allison>

Are there plans to offer lineage-committed derivatives?

<Dr. Angelica Gomes Ueltschy>

Yeah definitely in the future we have plans to offer specialized blood cell types. In the moment we are in the R&D phase. I would say that the most advanced protocols are macrophages and dendritic cells. We have used our HPCs to differentiate into monocyte than into macrophages and also monocytes into dendritic cells. And than if these cells are functional we conduct functional tests both on the macrophages and dendritic cells. So yeah in the future we will have specialized cell types,  in the moment we are in R&D.  

<Dr. Tom Allison>

Have you been able to maintain these HPCs for any period of time post thaw and maintain the HSC marker expression that was presented? 

<Dr. Angelica Gomes Ueltschy>

That is a really good question. It is a big challenge for the whole field in the HSCs, right, to expand them and maintain their stemness. I haven’t done these studies yet, but I am confident to say that it is really hard to expand the cells and maintain the state. Whenever the cells are cultured in some cytokine cocktail they start differentiating. So yeah i haven’t done that and this is possibly a challenge for the whole field.  

<Dr. Tom Allison>

Have you tested your HPCs with cancer organoids from patient samples 

<Dr. Angelica Gomes Ueltschy>

So yeah we have done differentiation of HPCs using 2 cell lines that we have in house.  And the differentiation protocol that we have was robust on the 2 cell lines tested. Additionally, we have tested 2 other cell lines being 1 diseased – a disease related cell line from a collaborator. So basically he shipped the  cells for us and we conducted our differentiation protocol in house and we got good HPC differentiation so far for different cell lines.  So yeah we are open for differentiation services in which we are going to receive your iPSC cell line and differentiate them to the lineage you are looking for.  

<Dr. Tom Allison>

Have you ever tried to engraft these cells? 

<Dr. Angelica Gomes Ueltschy>

Thank you for this question since this is a really hot topic and really popular topic right now. I haven’t done that but I think its interesting and I am open to test that, I just haven’t had the time yet. 

<Dr. Tom Allison>

What cell lines have you generated HPCs on and is it possible to perform the same differentiation on my cell line of interest? 

<Dr. Angelica Gomes Ueltschy>

This is a really important question – we are looking for the answer. We have started animal studies with these, but we are in the middle of it, we haven’t got any data yet, so yeah, we are waiting for the data, and we are excited to see that.  

<Dr. Tom Allison>

That concludes the questions that came in for this webinar, thank you Angelica for answering them and thank you again Michael for the presentation today. If you have any additional questions, please feel free to reach out to us at support@TrailBio.com. 

Again, this webinar will be hosted on the Trailhead website later this week. 

Thank you again for joining us today, and have a great rest of your day!