# Circulating subpopulations of non-cytotoxic ILCs in diffuse large B-cell lymphoma

## TL;DR

The study found that certain types of innate lymphoid cells (ILCs) are less frequent in patients with diffuse large B-cell lymphoma compared to healthy individuals, suggesting a potential role in tumor immunity.

## Contribution

The paper reports novel findings on the frequency and subset distribution of non-cytotoxic ILCs in diffuse large B-cell lymphoma patients.

## Key findings

- DLBCL patients had significantly lower levels of total ILCs, ILC1, and ILCp NCR- compared to healthy controls.
- A statistically significant decrease in NKp46+ ILC3 cells was observed in lymphoma patients.
- The distribution of ILC subpopulations correlated with tumor stage and location.

## Abstract

Non-cytotoxic innate lymphoid cells (ILCs) have been added to the list of immune cells that may contribute to the tumor microenvironment. Elevated levels of total ILCs and their subgroups have been reported in peripheral blood and tissue samples from patients with solid tumors, but their frequency in non-Hodgkin lymphomas, particularly diffuse large B-cell lymphoma (DLBCL), has not been clearly established. This study examined frequency and subset distribution in newly diagnosed DLBCL patients (nodal and extra-nodal) and compared it with blood specimens from healthy donors. The percentage of total ILCs (Lin − CD127+) was assessed by flow cytometry, as well as the four ILC subsets, defined as ILC1 (Lin − CD127 + cKit − CRTH2−), ILC2 (Lin − CD127 + cKit+/- CRTH2+), ILCp NCR- (Lin − CD127 + cKit + CRTH2- NKp46-) and NCR + ILC3 (Lin − CD127 + cKit + NKp46+). In the studied group of patients (n = 54), significantly lower levels of circulating total ILCs, ILC1, and ILCp NCR- were observed compared to the control group (n = 43). Similarly, there was a statistically significant decrease in the median frequency of NKp46 + ILC3 cells in lymphoma patients. Analysis of the ILC2 subpopulation showed no significant differences. The correlation of the distribution of individual subpopulations of ILCs with the stage and location of the tumor was also demonstrated. Our results suggest that circulating ILCs are activated and differentiated and/or differentially recruited to the lymph nodes or tumor microenvironment where they may be involved in antitumor defense. However, our observations require confirmation in functional studies.