Although checkpoint inhibitors that block CTLA-4 and PD-1 have improved cancer immunotherapies, targeting additional checkpoint receptors may be required to broaden patient response to immunotherapy. PVRIG is a coinhibitory receptor of the DNAM/TIGIT/CD96 nectin family that binds to PVRL2. We report that antagonism of PVRIG and TIGIT, but not CD96, increased CD8 þ T-cell cytokine production and cytotoxic activity. The inhibitory effect of PVRL2 was mediated by PVRIG and not TIGIT, demonstrating that the PVRIG-PVRL2 pathway is a nonredundant signaling node. A combination of PVRIG blockade with TIGIT or PD-1 blockade further increased T-cell activation. In human tumors, PVRIG expression on T cells was increased relative to normal tissue and trended with TIGIT and PD-1 expression. Tumor cells coexpressing PVR and PVRL2 were observed in multiple tumor types, with highest coexpression in endometrial cancers. Tumor cells expressing either PVR or PVRL2 were also present in numbers that varied with the cancer type, with ovarian cancers having the highest percentage of PVR À PVRL2 þ tumor cells and colorectal cancers having the highest percentage of PVR þ PVRL2 À cells. To demonstrate a role of PVRIG and TIGIT on tumor-derived T cells, we examined the effect of PVRIG and TIGIT blockade on human tumor-infiltrating lymphocytes. For some donors, blockade of PVRIG increased T-cell function, an effect enhanced by combination with TIGIT or PD-1 blockade. In summary, we demonstrate that PVRIG and PVRL2 are expressed in human cancers and the PVRIG-PVRL2 and TIGIT-PVR pathways are nonredundant inhibitory signaling pathways. See related article on p. 244

The adult human liver is enriched with natural killer (NK) cells, accounting for 30-50% of hepatic lymphocytes, which include tissue-resident hepatic NK-cell subpopulations, distinct from peripheral blood NK cells. In murine liver, a subset of liver-resident hepatic NK cells have altered expression of the two highly related T-box transcription factors, T-bet and eomesodermin (Eomes). Here, we investigate the heterogeneity of T-bet and Eomes expression in NK cells from healthy adult human liver with a view to identifying humanliver-resident populations. Hepatic NK cells were isolated from donor liver perfusates and biopsies obtained during orthotopic liver transplantation (N = 28). Hepatic CD56 bright NK cells were Eomes hi T-bet lo , a phenotype virtually absent from peripheral blood. These NK cells express the chemokine receptor CXCR6 (chemokine (C-X-C motif) receptor 6), a marker of tissue residency, which is absent from hepatic CD56 dim and blood NK cells. Compared to blood populations, these hepatic CD56 bright NK cells have increased expression of activatory receptors (NKp44, NKp46, and NKG2D). They show reduced ability to produce IFN-γ but enhanced degranulation in response to challenge with target cells. This functionally distinct population of hepatic NK cells constitutes 20-30% of the total hepatic lymphocyte repertoire and represents a tissue-resident immune cell population adapted to the tolerogenic liver microenvironment. Eur. J. Immunol. 2016Immunol. . 46: 2111Immunol. -2120 less cytokines than the CD56 bright population [1,2]. Studies in knockout mice have identified a number of transcription factors essential for the developmental program of NK cells, such as Nfil3, Id2,, as well as the two highly related T-box transcription factors, T-bet and eomesodermin (Eomes) [6,7]. In the bone marrow (BM), T-bet expression is initially repressed, allowing the development of Eomes + NK-cell precursors, with T-bet expression subsequently increased during the final stages of NKcell maturation [6]. While conventional NK cells circulate in the PB, transiting through several organs, significant NK-cell populations also permanently reside in tissues such as the lung, gut, uterus, and liver and may develop there [8]. Among these tissue-resident NK-cell populations, the role of uterine NK cells in successful pregnancy is well described [9]; however, the functions of other heterogeneous tissue-resident NK-cell populations remain largely unknown. Within these tissue microenvironments, it is evident that the developmental, functional, and phenotypic features of NK-cell subsets are poorly characterized compared to their PB counterparts [10]. Keywords: CD56 bright natural killer (NK) cells Human liver Interferon MicroenvironmentThe adult human liver contains a unique and extensive lymphoid repertoire. There is a predominance of innate lymphoid cells including NK cells, NKT cells, mucosal-associated invariant T cells and γδ T cells in the liver, in addition to the presence of conventional CD4 + and CD8 + lymphocytes of ...

Poor myeloid engraftment remains a barrier to experimental use of humanized mice. Focusing primarily on peripheral blood cells, we compared the engraftment profile of NOD-scid-IL2Rγc(-/-) (NSG) mice with that of NSG mice transgenic for human membrane stem cell factor (hu-mSCF mice), NSG mice transgenic for human interleukin (IL)-3, granulocyte-macrophage-colony stimulating factor (GM-CSF), and stem cell factor (SGM3 mice). hu-mSCF and SGM3 mice showed enhanced engraftment of human leukocytes compared to NSG mice, and this was reflected in the number of human neutrophils and monocytes present in these strains. Importantly, discrete classical, intermediate, and nonclassical monocyte populations were identifiable in the blood of NSG and hu-mSCF mice, while the nonclassical population was absent in the blood of SGM3 mice. Granulocyte-colony stimulating factor (GCSF) treatment increased the number of blood monocytes in NSG and hu-mSCF mice, and neutrophils in NSG and SGM3 mice; however, this effect appeared to be at least partially dependent on the stem cell donor used to engraft the mice. Furthermore, GCSF treatment resulted in a preferential expansion of nonclassical monocytes in both NSG and hu-mSCF mice. Human tubulointerstitial CD11c(+) cells were present in the kidneys of hu-mSCF mice, while monocytes and neutrophils were identified in the liver of all strains. Bone marrow-derived macrophages prepared from NSG mice were most effective at phagocytosing polystyrene beads. In conclusion, hu-mSCF mice provide the best environment for the generation of human myeloid cells, with GCSF treatment further enhancing peripheral blood human monocyte cell numbers in this strain.

Background:Tumour gene expression analysis is useful in predicting adjuvant chemotherapy benefit in early breast cancer patients. This study aims to examine the implications of routine Oncotype DX testing in the UK.Methods:Women with oestrogen receptor positive (ER+), pNO or pN1mi breast cancer were assessed for adjuvant chemotherapy and subsequently offered Oncotype DX testing, with changes in chemotherapy decisions recorded. A subset of patients completed questionnaires about their uncertainties regarding chemotherapy decisions pre- and post-testing. All patients were asked to complete a diary of medical interactions over the next 6 months, from which economic data were extracted to model the cost-effectiveness of testing.Results:Oncotype DX testing resulted in changes in chemotherapy decisions in 38 of 142 (26.8%) women, with 26 of 57 (45.6%) spared chemotherapy and 12 of 85 (14.1%) requiring chemotherapy when not initially recommended (9.9% reduction overall). Decision conflict analysis showed that Oncotype DX testing increased patients' confidence in treatment decision making. Economic analysis showed that routine Oncotype DX testing costs £6232 per quality-adjusted life year gained.Conclusion:Oncotype DX decreased chemotherapy use and increased confidence in treatment decision making in patients with ER+ early-stage breast cancer. Based on these findings, Oncotype DX is cost-effective in the UK setting.

Key PointsQuestionIs the anti–interleukin-1β antibody canakinumab effective to treat patients hospitalized with COVID-19 and hyperinflammation?FindingThis randomized clinical trial included 454 patients hospitalized with severe COVID-19 not requiring invasive mechanical ventilation (IMV) and with elevated C-reactive protein or ferritin levels. Treatment with intravenous canakinumab vs placebo resulted in survival without IMV at 29 days of 88.8% vs 85.7%, a difference that was not statistically significant.MeaningAmong patients hospitalized with severe COVID-19, treatment with canakinumab, compared with placebo, did not significantly increase the likelihood of survival without IMV.