An Atlas of Human Regulatory T Helper-like Cells Reveals Features of Th2-like Tregs that Support a Tumorigenic Environment

Regulatory T cells (Tregs) play a pivotal role in maintaining immunological tolerance, but they can also play a detrimental role by preventing antitumor responses. Here, we characterized T helper (Th)-like Treg subsets to further delineate their biological function and tissue distribution, focusing on their possible contribution to disease states. RNA sequencing and functional assays revealed that Th2-like Tregs displayed higher viability and autocrine interleukin-2 (IL-2)-mediated activation than other subsets. Th2-like Tregs were preferentially found in tissues rather than circulation and exhibited the highest migratory capacity toward chemokines enriched at tumor sites. These cellular responses led us to hypothesize that this subset could play a role in maintaining a tumorigenic environment. Concurrently, Th2-like Tregs were enriched specifically in malignant tissues from patients with melanoma and colorectal cancer compared to healthy tissue. Overall, our results suggest that Th2-like Tregs may contribute to a tumorigenic environment due to their increased cell survival, higher migratory capacity, and selective T-effector suppressive ability. Graphical Abstrac

Steroid regulation: An overlooked aspect of tolerance and chronic rejection in kidney transplantation.

Steroid conversion (HSD11B1, HSD11B2, H6PD) and receptor genes (NR3C1, NR3C2) were examined in kidney-transplant recipients with "operational tolerance" and chronic rejection (CR), independently and within the context of 88 tolerance-associated genes. Associations with cellular types were explored. Peripheral whole-blood gene-expression levels (RT-qPCR-based) and cell counts were adjusted for immunosuppressant drug intake. Tolerant (n = 17), stable (n = 190) and CR patients (n = 37) were compared. Healthy controls (n = 14) were used as reference. The anti-inflammatory glucocorticoid receptor (NR3C1) and the cortisol-activating HSD11B1 and H6PD genes were up-regulated in CR and were lowest in tolerant patients. The pro-inflammatory mineralocorticoid gene (NR3C2) was downregulated in stable and CR patients. NR3C1 was associated with neutrophils and NR3C2 with T-cells. Steroid conversion and receptor genes, alone, enabled classification of tolerant patients and were major contributors to gene-expression signatures of both, tolerance and CR, alongside known tolerance-associated genes, revealing a key role of steroid regulation and response in kidney transplantation

IFI27 transcription is an early predictor for COVID-19 outcomes, a multi-cohort observational study

PurposeRobust biomarkers that predict disease outcomes amongst COVID-19 patients are necessary for both patient triage and resource prioritisation. Numerous candidate biomarkers have been proposed for COVID-19. However, at present, there is no consensus on the best diagnostic approach to predict outcomes in infected patients. Moreover, it is not clear whether such tools would apply to other potentially pandemic pathogens and therefore of use as stockpile for future pandemic preparedness.MethodsWe conducted a multi-cohort observational study to investigate the biology and the prognostic role of interferon alpha-inducible protein 27 (IFI27) in COVID-19 patients.ResultsWe show that IFI27 is expressed in the respiratory tract of COVID-19 patients and elevated IFI27 expression in the lower respiratory tract is associated with the presence of a high viral load. We further demonstrate that the systemic host response, as measured by blood IFI27 expression, is associated with COVID-19 infection. For clinical outcome prediction (e.g., respiratory failure), IFI27 expression displays a high sensitivity (0.95) and specificity (0.83), outperforming other known predictors of COVID-19 outcomes. Furthermore, IFI27 is upregulated in the blood of infected patients in response to other respiratory viruses. For example, in the pandemic H1N1/09 influenza virus infection, IFI27-like genes were highly upregulated in the blood samples of severely infected patients.ConclusionThese data suggest that prognostic biomarkers targeting the family of IFI27 genes could potentially supplement conventional diagnostic tools in future virus pandemics, independent of whether such pandemics are caused by a coronavirus, an influenza virus or another as yet-to-be discovered respiratory virus

B cell regulation of the anti-tumor response and role in carcinogenesis

The balance between immune effector cells such as T cells and natural killer cells, and immunosuppressive Treg cells, dendritic, myeloid and monocytic sub-populations in the tumor microenvironment acts to calibrate the immune response to malignant cells. Accumulating evidence is pointing to a role for B cells in modulating the immune response to both solid tumors and hematologic cancer. Evidence from murine autoimmune models has defined B regulatory cell (Breg) subsets that express cytokines such as IL-10, TGF-β, and/or express immune regulatory ligands such as PD-L1, which can suppress T cell and/or natural killer cell responses. Multiple murine tumor models exhibit decreased tumor growth in B cell deficient or B cell depleted mice. In several of these models, B cells inhibit T cell mediated tumor immunity and/or facilitate conversion of T cells to CD4(+)CD25(+)FoxP3(+) T regs, which act to attenuate the innate and/or adaptive antitumor immune response. Mechanisms of suppression include the acquisition of inhibitory ligand expression, and phosphorylation of Stat3, and induction of IL-10 and TGF-β, resulting in a Breg phenotype. Breg suppressive activity may affect diverse cell subtypes, including T effector cells, NK cells, myeloid derived suppressor cells (MDSC) and/or tumor associated macrophages. B cells may also directly promote tumorigenesis through recruitment of inflammatory cells, and upregulation of pro-angiogenic genes and pro-metastatic collagenases. Breg infiltration has now been identified in a variety of solid tumor malignancies including but not limited to ovarian, gastric, non-small cell lung cancer, pancreatic, esophageal, head and neck, and hepatocellular carcinomas. Increasing evidence suggests that recruitment of B cells and acquisition of suppressive activity within the tumor bed may be an important mechanism through which B cells may modulate innate and/or adaptive anti-tumor immunity. B cell depletion in the clinic using anti-CD20 antibodies and/or inhibitors of BTK and/or other signaling pathways, may be a useful strategy for augmenting the anti-tumor immune response