When our immune systems identify invaders – such as parasites, bacteria or viruses – it can spark inflammation, which brings fluid and immune cells to the area of infection. While this can be very effective in battling infection, it also has collateral damage on nearby healthy tissues. In our daily lives, just by eating or breathing, we are constantly exposing our immune systems to microbes and particulate matter that can elicit low level inflammatory responses. The impact of these events over time is not well understood.
Mononuclear phagocyte cells (MPs) are myeloid cells and key regulators in the inflammatory process. They are present in every tissue and are very diverse with multiple origins.
When did you first become interested in multiplex tissue microscopy?
When we read this paper from Dr. Garry Nolan’s group at Stanford University (USA), we got very excited because they presented a very solid and elegant strategy to detect more than 40 markers/antibodies, simultaneously, which they called CODEX Multiplexed Imaging. In 2019, we learned that Akoya Biosciences was creating a commercialized system and we decided to establish it in our group. An important element was selecting the proper microscope that could integrate with the Akoya Biosciences solution. Although there were several options in the market, the ZEISS Axio Observer microscope offered the best sensitivity and an optimal speed of acquisition. We can acquire the full left murine lung stained with 40 antibodies in less than 32 hours.
How has the Axio Observer microscope with CODEX workflow changed your research?
Before acquiring the Axio Observer microscope and the CODEX multiplex system, our findings were mainly based on high dimensional flow cytometry and single-cell transcriptomics. Although both approaches allow a deep understanding of immune responses at a single cell level, they lack spatial resolution and context.
However, cells do not live in isolation but are part of an intricate network of interactions and interdependence. We realized we needed to find a way to study the complexity of the innate immune system while keeping the context of the tissue.
The incorporation of a highly multiplexed imaging technique that allows visualizing at a single-cell level more than 40 cell markers in record time without compromising tissue morphology or image quality has brought our research to another level of understanding. With CODEX we want to (and have been able to) visualize major tissue morphological changes induced by different conditions, localize cells of interest, characterize the surrounding of these cells, look at their interaction partners and determine how the local environment shapes the function of a cell. It has been fascinating to see how using the CODEX technology with our Axio Observer microscope adds a whole new dimension/parameter to the insights we are able to obtain.
These datasets are just really amazing windows into cell biology!
Can you provide a teaser about your initial findings?
We have been using the system for a year and we keep finding ways to pull out more and better information through our analysis pipeline. Basically almost all of our current projects are profiting from the CODEX multiplex tissue microscopy system workflow! We have a couple of projects that have started with an exploration of the spatial distribution and diversity of myeloid cells using CODEX. For example, we have looked at macrophages and dendritic cells in the longitudinal axis of the murine large intestine and found that there is a gradient in their distribution. We are currently focusing on the characterization of macrophage populations that we observe in the different layers of the intestinal wall and would like to use spatial-omics in fate mapping mouse models to track their origin.