Alessandro Camponeschi

The COVID‐19 pandemic began as a health crisis and quickly turned into an economic, social, and political crisis. It revealed the vulnerability of education systems to external changes and risks and challenged institutions and educators to transform and adapt at short notice. Following the COVID‐19 outbreak, one of the natural consequences was the unprecedented rise in online education. The transition from the in‐person teaching format to e‐learning exposed teachers and students to significant challenges. In the biomedical field, e‐learning forced teachers to rethink hands‐on wet lab teaching into a hands‐off virtual one; this digital transformation has continued in the post‐pandemic period and has resulted in the emergence of hybrid models trying to harmonize the benefits of e‐learning with those of in‐person teaching. In this narrative review, we analyzed articles published between 2020 and 2024 focusing on the teaching of molecular and cellular biology laboratory through online or blended learning formats. We focused on the impact that pedagogical innovation in laboratory e‐learning has had on student perceptions, experience, and outcomes. We have extracted five major themes that should be considered by educators involved in course design to enhance the benefits of exposing students to learning in a virtual lab: (1) the varying effectiveness of laboratory e‐learning, (2) the potential for online labs to foster self‐efficacy and confidence, (3) the reduced opportunities for social interaction in virtual settings, (4) students' perspectives on virtual, blended, and in‐person lab work, and (5) the importance of addressing student inequities in digital access.

Men develop larger infarct sizes than women after a myocardial infarction (MI), but the mechanism underlying this sex difference is unknown. Here, we demonstrated that blood neutrophil counts post-MI were higher in male than female mice. Castration-induced testosterone deficiency reduced blood neutrophil counts to the level in females and increased survival post-MI. These effects were mimicked by Osterix-directed ablation of the androgen receptor in bone marrow (BM). Mechanistically, androgens downregulated the leukocyte retention factor CXCL12 in BM stromal cells. Post-hoc analysis of clinical trial data showed that neutrophilia was greater in men than women after reperfusion of first-time ST-elevation MI, and tocilizumab, an interleukin-6 receptor inhibitor, reduced blood neutrophil counts and infarct size to a greater extent in men than women. Our work reveals a previously unknown mechanism connecting testosterone with neutrophilia and MI injury via BM and identifies the importance of considering sex when developing anti-inflammatory strategies to treat MI.

Females exhibit a more robust immune response to both self-antigens and non-self-antigens than males, resulting in a higher prevalence of autoimmune diseases but more effective responses against infection. Increased expression of X-linked immune genes in female T cells is thought to underlie this enhanced response. Here we isolate thymocytes from pediatric thymi of healthy males (46, XY), females (46, XX), a female with completely skewed X-chromosome inactivation (46, XX, cXCI) and a female with Turner syndrome (45, X0). Using whole exome sequencing, RNA sequencing and DNA methylation data, we present a sex-aware expression profile of T cell development and generate a high-resolution map of escape from X-chromosome inactivation (XCI). Unexpectedly, XCI is transcriptionally and epigenetically stable throughout T cell development, and is independent of expression of XIST, the lncRNA responsible for XCI initiation during early embryonic development. In thymocytes, several genes known to escape XCI are expressed from only one X-chromosome. Additionally, we further reveal that a second X-chromosome is dispensable for T cell development. Our study thus provides a high-resolution map of XCI during human development and suggests a re-evaluation of XCI in sex differences in T cell function.

Background Pediatric Burkitt's lymphoma (pBL) is the most common childhood non-Hodgkin's B-cell lymphoma. Despite the encouraging survival rates for most children, treating cases with relapse and resistance to current therapies remains challenging. CD38, a transmembrane protein highly expressed in pBL, is a promising therapeutic target. This study investigates the effectiveness of CD38-targeting monoclonal antibodies (mAbs), daratumumab (DARA) and isatuximab (ISA), in impairing crucial cellular processes and survival pathways in pBL malignant cells. Methods In silico analyses of pBL cell line and patient sample datasets, combined with in vitro experiments using the Ramos cell line model, were conducted to assess the impact of DARA and ISA on cellular proliferation, apoptosis, and the phosphoinositide 3-kinase (PI3K) pathway. Comparative approaches were utilized to evaluate the therapeutic potential of these mAbs, focusing on B-cell receptor signaling, calcium flux, metabolic shifts, and interaction of key proteins on the cell surface. Results ISA was found to be more effective than DARA in disrupting B-cell receptor signaling, reducing cellular proliferation, and inducing apoptosis. Additionally, ISA caused a significant impairment of the PI3K pathway and induced metabolic shifts in pBL cells, indicating its role in metabolic reprogramming. The study also revealed a correlation between CD38 and MYC expression levels in pBL patient samples, suggesting CD38's involvement in key oncogenic processes. Conclusions The study emphasizes the therapeutic potential of CD38-targeting mAbs, particularly ISA, in pBL. These findings suggest that targeting CD38 with mAbs may offer a novel approach for treating pBL, particularly in cases where patients show resistance or relapse after conventional therapies.

Objectives: Paediatric Burkitt's lymphoma (pBL) is the most common childhood non‐Hodgkin B‐cell lymphoma. Despite the encouraging survival rates for most children, treating cases with relapse/resistance to current therapies remains challenging. CD38 is a transmembrane protein highly expressed in pBL. This study investigates the effectiveness of CD38‐targeting monoclonal antibodies (mAbs), daratumumab and isatuximab, in impairing crucial cellular processes and survival pathways in pBL malignant cells.Methods: In silico analyses of patient samples, combined with in vitro experiments using the Ramos cell line, were conducted to assess the impact of daratumumab and isatuximab on cellular proliferation, apoptosis and the phosphoinositide 3‐kinase (PI3K) pathway.Results: Isatuximab was found to be more effective than daratumumab in disrupting B‐cell receptor signalling, reducing cellular proliferation and inducing apoptosis. Additionally, isatuximab caused a significant impairment of the PI3K pathway and induced metabolic reprogramming in pBL cells. The study also revealed a correlation between CD38 and MYC expression levels in pBL patient samples, suggesting CD38 involvement in key oncogenic processes.Conclusion: The study emphasises the therapeutic potential of CD38‐targeting mAbs, particularly isatuximab, in pBL.

B and T cells are integral parts of the immune system and are implicated in many diseases, e.g. autoimmunity. Towards understanding the biology of B and T cells and subsets thereof, their transcriptomes can be analyzed using single-cell RNA sequencing. In some studies, the V(D)J transcripts encoding the variable regions of the B- and T-cell antigen receptors have been removed before the analyses. However, a systematic analysis of the effects of including versus excluding these genes is currently lacking. We have investigated the effects of these transcripts on unsupervised clustering and down-stream analyses of single-cell RNA sequencing data from B and T cells. We found that exclusion of the B−/T-cell receptor genes prior to unsupervised clustering resulted in clusters that represented biologically meaningful subsets, such as subsets of memory B and memory T cells. Furthermore, pseudo-time and trajectory inference analyses of early B-lineage cells resulted in a developmental pathway from progenitor to immature B cells. In contrast, when the B−/T-cell receptor genes were not removed, with the PCs used for clustering consisting of up to 70% V-genes, this resulted in some clusters being defined exclusively by V-gene segments. These did not represent biologically meaningful subsets; for instance in the early B-lineage cells, these clusters contained cells representing all developmental stages. Thus, in studies of B and T cells, to derive biologically meaningful results, it is imperative to remove the gene sequences that encode B- and T-cell receptors.

CD38 is a multifunctional protein expressed on the surface of B cells in healthy individuals but also in B cell malignancies. Previous studies have suggested a connection between CD38 and components of the IgM class B cell antigen receptor (IgM-BCR) and its coreceptor complex. Here, we provide evidence that CD38 is closely associated with CD19 in resting B cells and with the IgM-BCR upon engagement. We show that targeting CD38 with an antibody, or removing this molecule with CRISPR/Cas9, inhibits the association of CD19 with the IgM-BCR, impairing BCR signaling in normal and malignant B cells. Together, our data suggest that CD38 is a new member of the BCR coreceptor complex, where it exerts a modulatory effect on B cell activation upon antigen recognition by regulating CD19. Our study also reveals a new mechanism where α-CD38 antibodies could be a valuable option in therapeutic approaches to B cell malignancies driven by aberrant BCR signaling.

Editorial: The B-Side of B Cells

Essential mixed cryoglobulinaemia (EMC) is a disorder of B-cells producing rheumatoid factor (RF), and is clinically and immunologically similar to mixed cryoglobulinaemia (MC) related to hepatitis C virus (HCV-MC). We report here the first comprehensive analysis of B-cell clonality, phenotype and function in EMC. The study population included 16 patients with EMC and 24 patients with HCV-MC. Molecular analysis was done for the detection of circulating clonal B cells and for B cell receptor sequencing. B-cell phenotype, proliferative response, apoptosis and ERK signaling were analysed by flow cytometry. Molecular analysis of immunoglobulin genes rearrangements revealed circulating B-cell clones in about half of patients, on average of smaller size than those found in HCV-MC patients. Sequence analysis showed usage of the same stereotyped RF-encoding B-cell receptors frequently expressed in HCV-MC and in primary Sjögren's syndrome. B-cells with low expression of CD21 (CD21low) and unusual homing and inhibitory receptors were increased in EMC and in HCV-MC, but at a significantly lower extent in the former. The CD21low B-cells of EMC and HCV-MC patients shared functional features of exhaustion and anergy, namely reduced proliferation upon ligation of Toll-like receptor 9, high constitutive expression of phosphorylated ERK, and proneness to spontaneous apoptosis. Our findings suggest a common pathogenetic mechanism in EMC, HCV-MC and primary Sjögren's syndrome, consisting of autoantigen-driven clonal expansion and exhaustion of selected RF-producing B-cells. The more massive clonal expansion in HCV-MC may be due to co-stimulatory signals provided by the virus.