Highlights d GMPs are heterogeneous at the transcriptomic and proteomic level d An early committed neutrophil progenitor (proNeu1) exists within GMPs d proNeu1 gives rise to proNeu2, sequentially differentiating into mature neutrophil d proNeu1 specifically expands during emergency granulopoiesis

T cell receptor (TCR) stimulation and cytokine cues drive the differentiation of CD4+ naïve T cells into effector T cell populations with distinct proinflammatory or regulatory functions. Unlike adult naïve T cells, human fetal naïve CD4+ T cells preferentially differentiate into FOXP3+ regulatory T (Treg) cells upon TCR activation independent of exogenous cytokine signaling. This cell-intrinsic predisposition for Treg differentiation is implicated in the generation of tolerance in utero; however, the underlying mechanisms remain largely unknown. Here, we identify epigenetic and transcriptional programs shared between fetal naïve T and committed Treg cells that are inactive in adult naïve T cells and show that fetal-derived induced Treg (iTreg) cells retain this transcriptional program. We show that a subset of Treg-specific enhancers is accessible in fetal naïve T cells, including two active superenhancers at Helios. Helios is expressed in fetal naïve T cells but not in adult naïve T cells, and fetal iTreg cells maintain Helios expression. CRISPR-Cas9 ablation of Helios in fetal naïve T cells impaired their differentiation into iTreg cells upon TCR stimulation, reduced expression of immunosuppressive genes in fetal iTreg cells such as IL10, and increased expression of proinflammatory genes including IFNG. Consequently, Helios knockout fetal iTreg cells had reduced IL-10 and increased IFN-γ cytokine production. Together, our results reveal important roles for Helios in enhancing preferential fetal Treg differentiation and fine-tuning eventual Treg function. The Treg-biased programs identified within fetal naïve T cells could potentially be used to engineer enhanced iTreg populations for adoptive cellular therapies.

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Lactating women can produce protective antibodies in their milk after vaccination, which has informed antenatal vaccination programs for diseases such as influenza and pertussis. However, whether SARS-CoV-2-specific antibodies are produced in human milk as a result of COVID-19 vaccination is still unclear. In this study, we show that lactating mothers who received the BNT162b2 vaccine secreted SARS-CoV-2-specific IgA and IgG antibodies into milk, with the most significant increase at 3–7 days post-dose 2. Virus-specific IgG titers were stable out to 4–6 weeks after dose 2. In contrast, SARS-CoV-2-specific IgA levels showed substantial decay. Vaccine mRNA was detected in few milk samples (maximum of 2 ng/ml), indicative of minimal transfer. Additionally, infants who consumed post-vaccination human milk had no reported adverse effects up to 28 days post-ingestion. Our results define the safety and efficacy profiles of the vaccine in this demographic and provide initial evidence for protective immunity conferred by milk-borne SARS-CoV-2-specific antibodies. Taken together, our study supports recommendations for uninterrupted breastfeeding subsequent to mRNA vaccination against COVID-19.

Importance: To examine the impact of SARS-CoV-2 vaccination of lactating mothers on human milk Objective: (1) To quantify SARS-CoV-2-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) in human milk of lactating mothers who received the BNT162b2 vaccine, with reference to a cohort convalescent from antenatal COVID-19, and healthy lactating mothers. (2) To detect and quantify vaccine mRNA in human milk after BNT162b2 vaccination. Design: Gestational Immunity For Transfer 2 (GIFT-2) is a prospective cohort study of lactating mothers who were due to receive two doses of BNT162b2 vaccine, recruited between 5th February 2021 and 9th February 2021. Setting: Lactating healthcare workers living in Singapore Participants: Convenience sample of ten lactating healthcare workers. Human milk samples were collected at four time points: pre-vaccination, 1 to 3 days after dose one, 7 to 10 days after dose one, and 3 to 7 days after dose two of the BNT162b2 vaccine. Exposure: Two doses of the BNT162b2 vaccine 21 days apart. Main Outcome and Measure: (i) SARS-CoV-2-specific IgA and IgG in human milk of lactating mothers who received BNT162b2 vaccine, (ii) Detection and quantification of vaccine mRNA in human milk after BNT162b2 vaccination. Results: Ten lactating healthcare workers aged 32.5 years (range 29 to 42) were recruited, with 40 human milk samples collected and analysed. SARS-CoV-2-specific IgA was predominant in human milk of lactating mothers who received BNT162b2 vaccine. The sharpest rise in antibody production was 3 to 7 days after dose two of the BNT162b2 vaccine, with medians of 1110 picomolar of anti-SARS-CoV-2 spike and 374 picomolar of anti-Receptor Binding Domain IgA. Vaccine mRNA was detected only on rare occasions, at a maximum concentration of 2 ng/mL. Infants had no reported adverse events, up to 28 days after ingestion of post-vaccination human milk. Conclusions and Relevance: In this cohort of ten lactating mothers following BNT162b2 vaccination, nine (90%) produced SARS-CoV-2 IgA, and ten (100%) produced IgG in human milk with minimal amounts of vaccine mRNA. Lactating individuals should continue breastfeeding in an uninterrupted manner after receiving mRNA vaccination for SARS-CoV-2.

PURPOSE. MicroRNAs are a class of small noncoding RNAs that negatively regulate gene expression by binding to complimentary sequences of target messenger RNA. Their roles in corneal lymphangiogenesis are largely unknown. This study was to investigate the specific role of microRNA-184 (mir-184) in corneal lymphangiogenesis (LG) in vivo and lymphatic endothelial cells (LECs) in vitro. METHODS.Standard murine suture placement model was used to study the expressional change of mir-184 in corneal inflammatory LG and the effect of synthetic mir-184 mimic on this process. Additionally, a human LEC culture system was used to assess the effect of mir-184 overexpression on cell functions in vitro.RESULTS. Expression of mir-184 was significantly downregulated in corneal LG and, accordingly, its synthetic mimic suppressed corneal lymphatic growth in vivo. Furthermore, mir-184 overexpression in LECs inhibited their functions of adhesion, migration, and tube formation in vitro.CONCLUSIONS. These novel findings indicate that mir-184 is involved critically in LG and potentially could be used as an inhibitor of the process. Further investigation holds the promise for divulging new therapies for LG disorders, which occur inside and outside the eye.

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Background: Ratios of differential blood counts (hematological indices, HIs) had been identified as prognostic variables in various cancers. In primary central nervous system lymphomas (PCNSLs), higher baseline neutrophil-lymphocyte ratio (NLR) in particular was found to portend a worse overall survival. However, it was often observed that differential counts shift drastically following steroid administration. Moreover, steroids are an important part of the arsenal against PCNSL due to its potent lymphotoxic effects. We showed that the effect of steroids on differential blood cell counts and HIs could be an early biomarker for subsequent progression-free (PFS) and overall survival (OS). Methods: This study retrospectively identified all adult patients who received a brain biopsy from 2008 to 2019 and had histologically confirmed PCNSL, and included only those who received chemoimmunotherapy, with documented use of corticosteroids prior to treatment induction. Different blood cell counts and HIs were calculated at three time-points: baseline (pre steroid), pre chemoimmunotherapy (post steroid) and post chemoimmunotherapy. Tumor progression and survival data were collected and analyzed through Kaplan–Meier estimates and Cox regression. We then utilized selected variables found to be significant on Kaplan–Meier analysis to generate a decision-tree prognostic model, the NNI-NCCS score. Results: A total of 75 patients who received chemoimmunotherapy were included in the final analysis. For NLR, OS was longer with higher pre-chemoimmunotherapy (post-steroid) NLR (dichotomized at NLR ≥ 4.0, HR 0.42, 95% CI: 0.21–0.83, p = 0.01) only. For platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR), OS was better for lower post-chemoimmunotherapy PLR (dichotomized at PLR ≥ 241, HR 2.27, 95% CI: 1.00 to 5.18, p = 0.05) and lower pre-chemoimmunotherapy (post-steroid) LMR (dichotomized at LMR ≥ 25.7, HR 2.17, 95% CI: 1.10 to 4.31, p = 0.03), respectively, only. The decision-tree model using age ≤ 70, post-steroid NLR > 4.0, and pre-steroid (baseline) NLR < 2.5 and the division of patients into three risk profiles—low, medium, and high—achieved good accuracy (area-under-curve of 0.78), with good calibration (Brier score: 0.16) for predicting 2-year overall survival. Conclusion: We found that post-steroid NLR, when considered together with baseline NLR, has prognostic value, and incorporation into a prognostic model allowed for accurate and well-calibrated stratification into three risk groups.