[eng] During last decade cancer therapies have undergone constant progress, as reflected in
the development of novel histological methods for diagnosis, personalized chemotherapy and
targeted therapy. Despite progress made in colorectal cancer (CRC) field, little can be done to
improve overall survival, even on early CRC stages (II-III), besides surgical resection in
combination with chemotherapy. Therefore, new biomarkers for early detection of the disease,
more innovative methods for patient stratification and the development of new
immunotherapeutic treatments become essential. Importantly, several studies have shown that
the tumor microenvironment plays a crucial role in CRC progression. In this context, this study
aimed to lay the groundwork for the first characterization of the membrane lipid fingerprint of
sorted immune cells, which eventually may infiltrate the tumor. For that end, our purpose was
to establish the lipidome of each cell type using MALDI-IMS technology, which exhibits a much
higher sensitivity compared to other MS technologies. Unexpectedly, this approach could not
be directly applied in sorted cells, as the spectra obtained were lacking the most relevant peaks.
Consequently, the study aims was reevaluated and it was focused on investigating the reason of
such failure and on setting up a successful procedure. The latter is essential for the optimal
development of one of the current research lines of the group. Thus, the procedure described
here should allow us characterizing the lipidome of any type of immune cells, even for rare
populations, of which there is no information available yet. The thorough description of immune
cells lipidome will also help for a better comprehension of the complex network of interactions
prevailing within the tumor microenvironment.