In vivo dendritic cell reprogramming for cancer immunotherapy. Science (New York, N.Y.) Immunotherapy can lead to long-term survival for some cancer patients, yet generalized success has been hampered by insufficient antigen presentation and exclusion of immunogenic cells from the tumor microenvironment. Here, we developed an approach to reprogram tumor cells in vivo by adenoviral delivery of the transcription factors PU.1, IRF8, and BATF3, which enabled them to present antigens as type 1 conventional dendritic cells. Reprogrammed tumor cells remodeled their tumor microenvironment, recruited, and expanded polyclonal cytotoxic T cells; induced tumor regressions; and established long-term systemic immunity in multiple mouse melanoma models. In human tumor spheroids and xenografts, reprogramming to immunogenic dendritic-like cells progressed independently of immunosuppression, which usually limits immunotherapy. Our study paves the way for human clinical trials of in vivo immune cell reprogramming for cancer immunotherapy. 10.1126/science.adn9083

Distinct roles of TREM2 in central nervous system cancers and peripheral cancers. Cancer cell Glioblastomas (GBM) are incurable central nervous system (CNS) cancers characterized by substantial myeloid cell infiltration. Whether myeloid cell-directed therapeutic targets identified in peripheral non-CNS cancers are applicable to GBM requires further study. Here, we identify that the critical immunosuppressive target in peripheral cancers, triggering receptor expressed on myeloid cells-2 (TREM2), is immunoprotective in GBM. Genetic or pharmacological TREM2 deficiency promotes GBM progression in vivo. Single-cell and spatial sequencing reveals downregulated TREM2 in GBM-infiltrated myeloid cells. TREM2 negatively correlates with immunosuppressive myeloid and T cell exhaustion signatures in GBM. We further demonstrate that during GBM progression, CNS-enriched sphingolipids bind TREM2 on myeloid cells and elicit antitumor responses. Clinically, high TREM2 expression in myeloid cells correlates with better survival in GBM. Adeno-associated virus-mediated TREM2 overexpression impedes GBM progression and synergizes with anti-PD-1 therapy. Our results reveal distinct functions of TREM2 in CNS cancers and support organ-specific myeloid cell remodeling in cancer immunotherapy. 10.1016/j.ccell.2024.05.001

Targeting CD39 in cancer. Moesta Achim K,Li Xian-Yang,Smyth Mark J Nature reviews. Immunology The ATP-adenosine pathway functions as a key modulator of innate and adaptive immunity within the tumour microenvironment. Consequently, multiple clinical strategies are being explored to target this pathway for the treatment of cancer; in particular, recent clinical data with CD73 antagonists and inhibitors of A receptors have demonstrated the therapeutic potential of modulating this pathway. Now, inhibitors of the ectonucleotidase CD39, the rate-limiting enzyme in the conversion of ATP to immunomodulatory adenosine, are entering clinical trials. Consequently, there is currently a focus on understanding the impact of CD39 enzymatic function on innate and adaptive immunity and how therapeutic modulation of this pathway alters their functional potential within the tumour microenvironment. Recent findings reveal multipronged mechanisms of action of CD39 antagonism that rely not only on preventing the accumulation of adenosine but also on the stabilization of pro-inflammatory extracellular ATP to restore antitumour immunity. Here, we review the impact of CD39 expression and ectonucleotidase activity on immunity with a focus on the setting of oncology. Additionally, we discuss the implications for immunotherapy strategies targeting CD39, including their inclusion in rational combination therapies. 10.1038/s41577-020-0376-4

Immune imprinting and next-generation coronavirus vaccines. Nature microbiology Vaccines based on historical virus isolates provide limited protection from continuously evolving RNA viruses, such as influenza viruses or coronaviruses, which occasionally spill over between animals and humans. Despite repeated booster immunizations, population-wide declines in the neutralization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have occurred. This has been compared to seasonal influenza vaccinations in humans, where the breadth of immune responses induced by repeat exposures to antigenically distinct influenza viruses is confounded by pre-existing immunity-a mechanism known as imprinting. Since its emergence, SARS-CoV-2 has evolved in a population with partial immunity, acquired by infection, vaccination or both. Here we critically examine the evidence for and against immune imprinting in host humoral responses to SARS-CoV-2 and its implications for coronavirus disease 2019 (COVID-19) booster vaccine programmes. 10.1038/s41564-023-01505-9