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Summary Kupffer cells (KCs) are highly abundant, intravascular, liver-resident macrophages known for their scavenger and phagocytic functions. KCs can also present antigens to CD8+ T cells and promote either tolerance or effector differentiation, but the mechanisms underlying these discrepant outcomes are poorly understood. Here, we used a mouse model of hepatitis B virus (HBV) infection, in which HBV-specific naive CD8+ T cells recognizing hepatocellular antigens are driven into a state of immune dysfunction, to identify a subset of KCs (referred to as KC2) that cross-presents hepatocellular antigens upon interleukin-2 (IL-2) administration, thus improving the antiviral function of T cells. Removing MHC-I from all KCs, including KC2, or selectively depleting KC2 impaired the capacity of IL-2 to revert the T cell dysfunction induced by intrahepatic priming. In summary, by sensing IL-2 and cross-presenting hepatocellular antigens, KC2 overcome the tolerogenic potential of the hepatic microenvironment, suggesting new strategies for boosting hepatic T cell immunity., Graphical abstract, Highlights • KCs are required for in vivo reinvigoration of intrahepatically primed T cells by IL-2 • KCs respond to IL-2 and cross-present hepatocellular Ags • Single-cell RNA-seq identifies two distinct populations of KCs • KC2s have enriched IL-2 sensing machinery and Ag presentation capacity, De Simone et al. delineate the mechanisms by which hepatocellularly primed HBV-specific CD8+ T cells acquire antiviral effector functions following IL-2 administration. These mechanisms rely on KCs and, in particular, on a hitherto unidentified KC subset, referred to as KC2, that is poised to respond to IL-2 and cross-present viral antigens.

Clonal cytopenia of undetermined significance (CCUS) is associated with an increased risk of developing a myeloid neoplasm with myelodysplasia (MN). To identify the features of the mutant clone(s) that is associated with clinical phenotype and progression, we studied the following cohorts of individuals: 311 patients with idiopathic cytopenia of undetermined significance (ICUS), 532 community-dwelling individuals without hematologic phenotype (n = 355) or with unexplained anemia (n = 177), and 592 patients with overt MN. Ninety-two of 311 (30%) patients with ICUS carried a somatic genetic lesion that signaled CCUS. Clonal hematopoiesis (CH) was detected in 19.7% and 27.7% of nonanemic and anemic community-dwelling individuals, respectively. Different mutation patterns and variant allele frequencies (VAFs) (clone metrics parameters) were observed in the conditions studied. Recurrent mutation patterns exhibited different VAFs associated with marrow dysplasia (0.17-0.48), indicating variable clinical expressivity of mutant clones. Unsupervised clustering analysis based on mutation profiles identified 2 major clusters, characterized by isolated DNMT3A mutations (CH-like cluster) or combinatorial mutation patterns (MN-like cluster), and showing different overall survival (HR, 1.8). In patients with CCUS, the 2 clusters had different risk of progression to MN (HR, 2.7). Within the MN-like cluster, distinct subsets with different risk of progression to MN were identified based on clone metrics. These findings unveil marked variability in the clinical expressivity of myeloid driver genes and underline the limitations of morphologic dysplasia for clinical staging of mutant hematopoietic clones. Clone metrics appears to be critical for informing clinical decision-making in patients with clonal cytopenia.

Antibody-mediated clearance of circulating HBsAg has minimal impact on the expansion of HBV-specific CD8+ T cells undergoing intrahepatic priming. It does not alter their differentiation into dysfunctional cells, nor does it enhance their functional restoration by immunotherapeutic strategies., Antibody-mediated clearance of hepatitis B surface antigen (HBsAg) from the circulation of chronically infected patients (i.e., seroconversion) is usually associated with increased HBV-specific T cell responsiveness. However, a causative link between serum HBsAg levels and impairment of intrahepatic CD8+ T cells has not been established. Here we addressed this issue by using HBV replication-competent transgenic mice that are depleted of circulating HBsAg, via either spontaneous seroconversion or therapeutic monoclonal antibodies, as recipients of HBV-specific CD8+ T cells. Surprisingly, we found that serum HBsAg clearance has only a minimal effect on the expansion of HBV-specific naive CD8+ T cells undergoing intrahepatic priming. It does not alter their propensity to become dysfunctional, nor does it enhance the capacity of IL-2–based immunotherapeutic strategies to increase their antiviral function. In summary, our results reveal that circulating HBsAg clearance does not improve HBV-specific CD8+ T cell responses in vivo and may have important implications for the treatment of chronic HBV infection., Graphical Abstract

Background Generic formulations of imatinib mesylate have been introduced in Western Europe since 2017 to treat patients with chronic myeloid leukemia (CML). However, results on the safety and efficacy of generic formulations are contrasting. The aim of this study was to investigate the safety and efficacy of generic imatinib in CML patients treated in 12 Italian institutes. Methods This is an observational, retro-prospective analysis of patients with CML for whom the treatment was switched from brand to generic imatinib. We analyzed and compared the variation in quantitative PCR values before and after the switch, and the proportion of patients who maintained molecular response after changing from brand to generic imatinib. Adverse events (AEs) were also evaluated. Results Two hundred patients were enrolled. The median PCR value after the switch was reduced by 0.25 compared to the values before the switch. A significant difference was found between median PCR values before and after the switch in favor of generic imatinib (P = 0.003). Molecular responses remained stable in 69.0%, improved in 25.5%, and worsened in 5.5% of patients. AEs were similar in the pre- and post-switch periods; however, a significant difference was found in favor of generic imatinib for muscular cramps (P < 0.0001), periorbital edema (P=0.0028), edema of the limbs (P

Differentiation of CD4+ T cells into either follicular helper T (TFH) or type 1 helper T (TH1) cells influences the balance between humoral and cellular adaptive immunity, but the mechanisms whereby pathogens elicit distinct effector cells are incompletely understood. Here we analyzed the spatiotemporal dynamics of CD4+ T cells during infection with recombinant vesicular stomatitis virus (VSV), which induces early, potent neutralizing antibodies, or recombinant lymphocytic choriomeningitis virus (LCMV), which induces a vigorous cellular response but inefficient neutralizing antibodies, expressing the same T cell epitope. Early exposure of dendritic cells to type I interferon (IFN), which occurred during infection with VSV, induced production of the cytokine IL-6 and drove TFH cell polarization, whereas late exposure to type I IFN, which occurred during infection with LCMV, did not induce IL-6 and allowed differentiation into TH1 cells. Thus, tight spatiotemporal regulation of type I IFN shapes antiviral CD4+ T cell differentiation and might instruct vaccine design strategies. Iannacone and colleagues show that the spatiotemporal regulation of type I interferon expression shapes the differentiation of antiviral CD4+ T cells into TFH or TH1 cells.

The aim of this paper is to disentangle the role of gender and partnership status in the caring commitments of older people (age 65 and over). Logistic and interval regression models are applied to individual records from the 2001 UK Census to estimate: (1) the impact of gender on the likelihood of being a carer; (2) the impact of gender on the hours of care provided; and (3) the impact of gender on the likelihood of being a carer for different groups defined by marital status. In the general population the share of women who provide care is higher than the corresponding share of men, but men have a higher probability of being carers among people aged 65 or above. This phenomenon is largely explained by gender differences in marital status. As older men are more likely to be married, and married people are more likely to be carers, we observe higher levels of caring among older men. Once differences in marital status are accounted for, the relationship between gender and care provision among older people is overturned. In particular, we find that, without controlling for household size, limiting long-term illness or marital status, the odds of being an informal carer are lower for older women than men [odds ratio (OR): 0.85; 95% confidence interval (CI): 0.83-0.87]. Once these factors are accounted for, older women have higher odds of caring than older men (OR: 1.12; 95% CI: 1.09-1.15). Restricting the sample to care providers, and controlling for the same factors, it is shown that older women supply on average 3.77 (95% CI: 3.14-4.40) more hours of care per week than older men. Gender differences in the provision of care among older people disappear only when considering married individuals and adjusting for the presence of other household residents affected by a limiting long-term illness.

The World Health Organization classification of myelodysplastic syndromes (MDS) is based on morphological evaluation of marrow dysplasia. We performed a systematic review of cytological and histological data from 1150 patients with peripheral blood cytopenia. We analyzed the frequency and discriminant power of single morphological abnormalities. A score to define minimal morphological criteria associated to the presence of marrow dysplasia was developed. This score showed high sensitivity/specificity (>90%), acceptable reproducibility and was independently validated. The severity of granulocytic and megakaryocytic dysplasia significantly affected survival. A close association was found between ring sideroblasts and SF3B1 mutations, and between severe granulocytic dysplasia and mutation of ASXL1, RUNX1, TP53 and SRSF2 genes. In myeloid neoplasms with fibrosis, multilineage dysplasia, hypolobulated/multinucleated megakaryocytes and increased CD34+ progenitors in the absence of JAK2, MPL and CALR gene mutations were significantly associated with a myelodysplastic phenotype. In myeloid disorders with marrow hypoplasia, granulocytic and/or megakaryocytic dysplasia, increased CD34+ progenitors and chromosomal abnormalities are consistent with a diagnosis of MDS. The proposed morphological score may be useful to evaluate the presence of dysplasia in cases without a clearly objective myelodysplastic phenotype. The integration of cytological and histological parameters improves the identification of MDS cases among myeloid disorders with fibrosis and hypocellularity.

We previously identified a cold shock domain (CSD)-containing protein (PIPPin), expressed at high level in brain cells. PIPPin has the potential to undergo different post-translational modifications and might be a good candidate to regulate the synthesis of specific proteins in response to extracellular stimuli. Here we report the effects of thyroid hormone (T3) on PIPPin expression in developing rat brain. We found that a significant difference among euthyroid- and hypothyroid- newborn rats concerns sumoylation of nuclear PIPPin, that is abolished by hypothyroidism. Moreover, T3-dependence of PIPPin sumoylation has been confirmed in cortical neurons purified from brain cortices and cultured in a chemically defined medium (Maat medium, MM), with or without T3. We also report that about one half of unmodified as well as all the sumoylated form of PIPPin could be extracted from nuclei with HCl, together with histones. Moreover, this HCl-soluble fraction remains in the nucleus even after treatment with 0.6 M KCl, thus suggesting strong interaction of PIPPin with nuclear structures and perhaps chromatin.

Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary endothelial cells in culture. In particular, we found that, in the presence of astrocytes, the neuron-induced synthesis and localization of occludin is precocious as compared to cells cocultured with neurons only.