Reprogramming Metastasis Infiltrating NK (MINKs) into tumor killers

In the present project, we will study the role of NK cells in the lymph node (LN) metastatic lesions of melanoma. Despite common knowledge assigns a potent anti-tumoral function to NK cells, some preliminary results from the applicant showed that the depletion of NK cells in a mouse model prevented the formation of melanoma metastatic lesions in the LN. Conversely, the primary tumor volume was not affected. These results suggest that NK cells play an essential role in the survival of LN metastasis of melanoma. We hypothesize that such a function is exploited by a subclass of metastasis infiltrating NK cells (MINK) with protumoral properties.

The aim of this project is to characterize the pro-tumoral MINK class and its function in melanoma metastasis, using mouse models and human samples. This study will be performed by analyzing the transcriptome of the MINK clusters at a single cell level (first aim). Importantly, a similar dataset has already been generated in our laboratory for an independent project not focusing on NK cells, but a detailed investigation of MINK has not been performed yet. Moreover, we will analyze the human counterparts of pro-tumoral MINK by using a spatial biology approach. The second aim of the study consists of reprogramming pro-tumoral MINK into tumor killing cells. This goal will be achieved by identifying the genes modulated in the pro-tumoral MINK, performing a connectivity map of this gene signature and comparing it with the signature of potential therapeutic compounds. Following this approach, we will be able to screen for candidate molecules able to reprogram pro-tumoral MINK and test them in vitro and in vivo.

The unconventionality of our approach resides in the identification of a novel NK subclass with pro-tumoral properties distinct from previously described mechanisms. Moreover, their mechanism appeared to be associated only with LN secondary lesions. A LN specific mechanism of cancer immune responses has not been observed before. Moreover, beside classical stimulation or CAR engineering, NK cells reprogramming from pro- to anti-tumoral has never been proposed so far.

The impact of the project consists in opening completely new scenarios on NK cells based immune responses in cancer. Moreover, NK reprogramming will offer the scientific community new strategies to re-shape NK cells based tumor immunotherapies. Finally, a LN specific mechanism will suggest new therapeutic pathways with high specificity for LN lesions, which are shared between almost all solid tumors and are critical for cancer progression and spread through the organism.

The project will ground on the expertise of the applicant and the other scientists involved in the project, which include scSeq analysis, mouse metastatic models, NK cells characterization, in vitro assays, and analysis of clinical samples from human patients.