Multimodal and spatially resolved profiling identifies distinct patterns of T cell infiltration in nodal B cell lymphoma entities.

The redirection of T cells has emerged as an attractive therapeutic principle in B cell non-Hodgkin lymphoma (B-NHL). However, a detailed characterization of lymphoma-infiltrating T cells across B-NHL entities is missing. Here we present an in-depth T cell reference map of nodal B-NHL, based on cellular indexing of transcriptomes and epitopes, T cell receptor sequencing, flow cytometry and multiplexed immunofluorescence applied to 101 lymph nodes from patients with diffuse large B cell, mantle cell, follicular or marginal zone lymphoma, and from healthy controls.

EOMES is essential for antitumor activity of CD8 T cells in chronic lymphocytic leukemia.

Genome-wide association studies identified a single-nucleotide polymorphism (SNP) affecting the transcription factor Eomesodermin (EOMES) associated with a significantly increased risk to develop chronic lymphocytic leukemia (CLL). Epigenetic analyses, RNA sequencing, and flow cytometry revealed that EOMES is not expressed in CLL cells, but in CD8 T cells for which EOMES is a known master regulator. We thus hypothesized that the increased CLL risk associated with the EOMES SNP might be explained by its negative impact on CD8 T-cell-mediated immune control of CLL.

Phosphoinositide 3-Kinase Signaling in the Tumor Microenvironment: What Do We Need to Consider When Treating Chronic Lymphocytic Leukemia With PI3K Inhibitors?

Phosphoinositide 3-kinases (PI3Ks) and their downstream proteins constitute a signaling pathway that is involved in both normal cell growth and malignant transformation of cells. Under physiological conditions, PI3K signaling regulates various cellular functions such as apoptosis, survival, proliferation, and growth, depending on the extracellular signals. A deterioration of these extracellular signals caused by mutational damage in oncogenes or growth factor receptors may result in hyperactivation of this signaling cascade, which is recognized as a hallmark of cancer.

EOMES and IL-10 regulate antitumor activity of T regulatory type 1 CD4 T cells in chronic lymphocytic leukemia.

The transcription factor eomesodermin (EOMES) promotes interleukin (IL)-10 expression in CD4 T cells, which has been linked to immunosuppressive and cytotoxic activities. We detected cytotoxic, programmed cell death protein-1 (PD-1) and EOMES co-expressing CD4 T cells in lymph nodes (LNs) of patients with chronic lymphocytic leukemia (CLL) or diffuse large B-cell lymphoma. Transcriptome and flow cytometry analyses revealed that EOMES does not only drive IL-10 expression, but rather controls a unique transcriptional signature in CD4 T cells, that is enriched in genes typical for T regulatory type 1 (T1) cells.

TBET-expressing Th1 CD4 T cells accumulate in chronic lymphocytic leukaemia without affecting disease progression in Eµ-TCL1 mice.

Chronic lymphocytic leukaemia (CLL) is associated with alterations in T cell number, subset distribution and function. Among these changes, an increase in CD4 T cells was reported. CD4 T cells are a heterogeneous population and distinct subsets have been described to exert pro- and anti-tumour functions.

CD8 T-cells of CLL-bearing mice acquire a transcriptional program of T-cell activation and exhaustion.

Chronic lymphocytic leukemia (CLL) is associated with an accumulation of oligoclonal CD8 effector T-cells, which control leukemia progression in mice, but gradually acquire a dysfunctional phenotype along with disease progression. Exhaustion of CD8 T-cells is characterized by increased expression of inhibitory receptors like PD-1, decreased proliferation, and reduced effector function such as cytokine production, which reduces anti-tumor control. Despite the accumulation of exhausted PD-1 CD8 T-cells in secondary lymphoid organs of CLL patients, immune checkpoint blockade as a means to reinvigorate anti-tumor T-cell activity has not shown the expected efficacy.

Tumor-derived exosomes modulate PD-L1 expression in monocytes.

In chronic lymphocytic leukemia (CLL), monocytes and macrophages are skewed toward protumorigenic phenotypes, including the release of tumor-supportive cytokines and the expression of immunosuppressive molecules such as programmed cell death 1 ligand 1 (PD-L1). To understand the mechanism driving protumorigenic skewing in CLL, we evaluated the role of tumor cell-derived exosomes in the cross-talk with monocytes. We carried out RNA sequencing and proteome analyses of CLL-derived exosomes and identified noncoding Y RNA hY4 as a highly abundant RNA species that is enriched in exosomes from plasma of CLL patients compared with healthy donor samples.