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Background Whether viral coinfections cause more severe disease than Bordetella pertussis (B. pertussis) alone remains unclear. We compared clinical disease severity and sought clinical and demographic differences between infants with B. pertussis infection alone and those with respiratory viral coinfections. We also analyzed how respiratory infections were distributed during the 2 years study. Methods We enrolled 53 infants with pertussis younger than 180 days (median age 58 days, range 17–109 days, 64.1% boys), hospitalized in the Pediatric Departments at “Sapienza” University Rome and Bambino Gesù Children’s Hospital from August 2012 to November 2014. We tested in naso-pharyngeal washings B. pertussis and 14 respiratory viruses with real-time reverse-transcriptase-polymerase chain reaction. Clinical data were obtained from hospital records and demographic characteristics collected using a structured questionnaire. Results 28/53 infants had B. pertussis alone and 25 viral coinfection: 10 human rhinovirus (9 alone and 1 in coinfection with parainfluenza virus), 3 human coronavirus, 2 respiratory syncytial virus. No differences were observed in clinical disease severity between infants with B. pertussis infection alone and those with coinfections. Infants with B. pertussis alone were younger than infants with coinfections, and less often breastfeed at admission. Conclusions In this descriptive study, no associations between clinical severity and pertussis with or without co-infections were found. Trial registration Policlinico Umberto I: protocol 213/14, 3085/13.02.2014, retrospectively registered. Bambino Gesù Children’s Hospital: protocol n. RF-2010-2317709.

BACKGROUND Pertussis infection can be severe in unvaccinated infants. A case-control study was conducted to investigate the potential role of breastfeeding in protecting young, unvaccinated infants from pertussis. METHODS Hospitalized infants

This study was planned to collect evidences of familial pertussis transmission to infants younger than 6 months of age. Understanding the dynamics of transmission of pertussis in families is essential to plan effective prevention strategies that could be integrated in pertussis control.The seroprevalence of IgG antibodies to pertussis toxin (PT-IgG) and prolonged cough symptoms were evaluated in parents of 55 infants aged6 months hospitalized for confirmed pertussis. Parents of 33 infants with lower respiratory tract infection (LRTI) and parents of 57 healthy infants admitted as outpatients for hip ultrasound examination (HE) were enrolled as controls.Parents of pertussis cases had PT-IgG levels significantly higher as compared to LRTI and HE parents. More than 40 % were compatible as transmitters of pertussis to their babies, since they had a level of PT-IgG ≥ 100 IU/ml, which is considered diagnostic for a recent pertussis episode. Based on serology, the percentage of pertussis cases that had at least one parent as source of infection was 49.1 %. When cough symptoms were taken into account, the percentage of parents putative transmitters of the infection to their infants increased to 56.4 %.Parents are scarcely aware of the household transmission of pertussis to their newborns. Our study highlights the need to advise parents about the likelihood of transmission to the newborn and to be particularly aware of coughing symptoms in the household. Since infection can be asymptomatic, a serological survey of family members should also be considered.

Several in vitro assays have been proposed to identify cancer stem cells (CSCs), including immunophenotyping, sphere assay and side population (SP) assay. CD133 antigen has been proposed as a CSC marker in colon cancer (CC). However, no functional data are available to date and conflicting results have been reported regarding its role as true CSC marker. Here we set out to identify a molecular signature associated with potential CSC. CD133(+) cells isolated from the CaCo-2 CC cell line were analysed by microarray molecular profiling compared to CD133(-) counterparts. Various differentially expressed genes were identified and the most relevant transcripts found to be over-expressed in CD133(+) cells were evaluated by quantitative RT-PCR in the CD133(+) fractions isolated from several CC cell lines. In the attempt to find a correlation between putative CSCs, isolated by means of CD133 immunophenotyping and the SP approach, we demonstrated a significant enrichment of CD133(+) cells within the SP fraction of CC cells, and comparison of the gene expression profiles revealed that Endothelin-1 (END-1) and nuclear receptor subfamily 4, group A, member 2 (NR4A2) transcripts are highly expressed in both CD133(+) and SP fractions of CC cells. Moreover, depletion of CD133 by siRNA induced a significant attenuation of END-1 and NR4A2 expression levels in CaCo-2 cells, while expression of all three molecules decreased during sodium butyrate-induced differentiation. In conclusion, we have identified a molecular signature associated with potential CSCs and showed for the first time the existence of a functional relationship between CD133, END-1 and NR4A2 expression in colon cancer cells.

To date there has been limited head-to-head evaluation of immune responses to different types of COVID-19 vaccines. A real-world population-based longitudinal study was designed with the aim to define the magnitude and duration of immunity induced by each of four different COVID-19 vaccines available in Italy at the time of this study. Overall, 2497 individuals were enrolled at time of their first vaccination (T0). Vaccine-specific antibody responses induced over time by Comirnaty, Spikevax, Vaxzevria, Janssen Ad26.COV2.S and heterologous vaccination were compared up to six months after immunization. On a subset of Comirnaty vaccinees, serology data were correlated with the ability to neutralize a reference SARS-CoV-2 B strain, as well as Delta AY.4 and Omicron BA.1. The frequency of SARS-CoV-2-specific CD4+ T cells, CD8+ T cells, and memory B cells induced by the four different vaccines was assessed six months after the immunization. We found that mRNA vaccines are stronger inducer of anti-Spike IgG and B-memory cell responses. Humoral immune responses are lower in frail elderly subjects. Neutralization of the Delta AY.4 and Omicron BA.1 variants is severely impaired, especially in older individuals. Most vaccinees display a vaccine-specific T-cell memory six months after the vaccination. By describing the immunological response during the first phase of COVID-19 vaccination campaign in different cohorts and considering several aspects of the immunological response, this study allowed to collect key information that could facilitate the implementation of effective prevention and control measures against SARS-CoV-2.

Lam et al. characterize a novel hematological/autoinflammatory disorder due to a de novo recurrent missense mutation of CDC42. The authors use in silico, in vitro, and in vivo analyses to correlate the molecular mechanisms altering CDC42 function to the observed phenotype., Hemophagocytic lymphohistiocytosis (HLH) is characterized by immune dysregulation due to inadequate restraint of overactivated immune cells and is associated with a variable clinical spectrum having overlap with more common pathophysiologies. HLH is difficult to diagnose and can be part of inflammatory syndromes. Here, we identify a novel hematological/autoinflammatory condition (NOCARH syndrome) in four unrelated patients with superimposable features, including neonatal-onset cytopenia with dyshematopoiesis, autoinflammation, rash, and HLH. Patients shared the same de novo CDC42 mutation (Chr1:22417990C>T, p.R186C) and altered hematopoietic compartment, immune dysregulation, and inflammation. CDC42 mutations had been associated with syndromic neurodevelopmental disorders. In vitro and in vivo assays documented unique effects of p.R186C on CDC42 localization and function, correlating with the distinctiveness of the trait. Emapalumab was critical to the survival of one patient, who underwent successful bone marrow transplantation. Early recognition of the disorder and establishment of treatment followed by bone marrow transplant are important to survival., Graphical Abstract

Bone marrow (BM)-derived mesenchymal stromal cells (MSCs), endowed with immunosuppressive and anti-inflammatory properties, represent a promising tool in immunoregulatory and regenerative cell therapy. Clarifying the interactions between MSCs and B-lymphocytes may be crucial for designing innovative MSC-based strategies in conditions in which B cells play a role, including systemic lupus erythematosus (SLE) and rejection of kidney transplantation. In this study, we show that, both in healthy subjects and in patients, in vitro B-cell proliferation, plasma-cell differentiation, and antibody production are inhibited by BM-derived MSCs when peripheral blood lymphocytes are stimulated with CpG, but not when sorted B cells are cultured with MSCs+CpG. Inhibition is restored in CpG+MSC cocultures when sorted T cells are added to sorted B cells, suggesting that this effect is mediated by T cells, with both CD4(+) and CD8(+) cells playing a role. Moreover, cell-cell contact between MSCs and T cells, but not between MSCs and B cells, is necessary to inhibit B-cell proliferation. Thus, the presence of functional T cells, as well as cell-cell contact between MSCs and T cells, are crucial for B-cell inhibition. This information can be relevant for implementing MSC-based therapeutic immune modulation in patients in whom T-cell function is impaired.

Hematopoietic cell transplantation (HCT) provides a curative therapy for severe forms of primary immunodeficiencies (PID). While the timing and extent of T-cell reconstitution following transplant for PID has been studied in depth, less is known about the kinetics of B-cell development and long-term restoration of humoral functions, which been often reported to be suboptimal after HCT. We studied longitudinally B-cell development and function in a cohort of 13 PID patients transplanted between 1997 and 2010, with a follow-up ranging from 0.7 to 15 years. Flow cytometric analysis of naive and antigen-experienced B-cell subsets and in vitro functional responses to CpG were compared with data from healthy children and correlated with the degree of B-cell chimerism and in vivo antibody production. We found that total memory B-cells count remained below normal levels for the first 2 years of follow up and progressively normalized. Switched memory B-cells (CD19+CD27+IgD-IgM-) were restored early and better than IgM memory B-cells (CD19+CD27+IgD+IgM+), which remained significantly reduced long-term. The recovery of memory B-cells correlated with good in vivo humoral function and normalization of CpG-response. A complete B-cell reconstitution was usually associated with donor B-cells chimerism and pre-transplant conditioning. Donor source and the underlying genetic defect represented also important variables. Monitoring of phenotypic and functional changes on B-cells following HCT may prove clinically relevant to tailor patients’ care. In particular the analysis of IgM memory and switched memory B-cells in addition to in vitro B-cells stimulation are recommended before Ig replacement therapy (IgRT) discontinuation.

In both Crohn’s disease (CD) and ulcerative colitis (UC), the gut is massively infiltrated with B cells and plasma cells, but the role of these cell types in the pathogenesis of gut tissue damage remains largely unknown. Human B cells express granzyme B (GrB) when cultured with IL-21, a cytokine overproduced in CD and UC mucosa. We therefore examined whether mucosal B cells express GrB and have cytotoxic activity in inflammatory bowel disease (IBD). GrB-expressing CD19+ and IgA+ cells were seen in the normal intestinal mucosa, but they were significantly more frequent in both CD and UC. In contrast, only a minority of CD19+ and IgA+ cells expressed perforin with no difference between IBD and controls. GrB-producing CD19+ cells expressed CD27 and were CD38high and CD20 negative. CD19+ B cells from IBD patients induced HCT-116 cell death. IL-21 enhanced GrB expression in control CD19+ B cells and increased their cytotoxic activity. These data indicate that IBD-related inflammation is marked by mucosal accumulation of cytotoxic, GrB-expressing CD19+ and IgA+ cells, suggesting a role for these cells in IBD-associated epithelial damage.

Twenty-three children with nonmalignant disorders received HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) after ex vivo elimination of αβ(+) T cells and CD19(+) B cells. The median number of CD34(+), αβ(+)CD3(+), and B cells infused was 16.8 × 10(6), 40 × 10(3), and 40 × 10(3) cells/kg, respectively. No patient received any posttransplantation pharmacologic prophylaxis for graft-versus-host disease (GVHD). All but 4 patients engrafted, these latter being rescued by a second allograft. Three patients experienced skin-only grade 1 to 2 acute GVHD. No patient developed visceral acute or chronic GVHD. Cumulative incidence of transplantation-related mortality was 9.3%. With a median follow-up of 18 months, 21 of 23 children are alive and disease-free, the 2-year probability of disease-free survival being 91.1%. Recovery of γδ(+) T cells was prompt, but αβ(+) T cells progressively ensued over time. Our data suggest that this novel graft manipulation strategy is safe and effective for haplo-HSCT. This trial was registered at www.clinicaltrials.gov as #NCT01810120.

Splenectomized patients are exposed to an increased risk of septicemia caused by encapsulated bacteria. Defense against infection is ensured by preformed serum antibodies produced by long-lived plasma cells and by memory B cells that secrete immunoglobulin in response to specific antigenic stimuli. Studying a group of asplenic individuals (57 adults and 21 children) without additional immunologic defects, we found that spleen removal does not alter serum anti-pneumococcal polysaccharide (PnPS) IgG concentration, but reduces the number of PnPS-specific memory B cells, of both IgM and IgG isotypes. The number of specific memory B cells was low in splenectomized adults and children that had received the PnPS vaccine either before or after splenectomy. Seven children were given the 13-valent pneumococcal conjugated vaccine after splenectomy. In this group, the number of PnPS-specific IgG memory B cells was similar to that of eusplenic children, suggesting that pneumococcal conjugated vaccine administered after splenectomy is able to restore the pool of anti-PnPS IgG memory B cells. Our data further elucidate the crucial role of the spleen in the immunological response to infections caused by encapsulated bacteria and suggest that glycoconjugated vaccines may be the most suitable choice to generate IgG-mediated protection in these patients.

The establishment of gut microbiota immediately after birth is modulated by different mechanisms that can be considered specific determinants of temporal and spatial variability. Over the last few years, molecular methods have been offering a complementary support to the classical microbiology, often underpowered by its inability to provide unbiased representation of gut microbiota. The advent of high-throughput-omics-based methods has opened new avenues in the knowledge of the gut ecosystem by shedding light on its shape and modulation. Such methods may unveil taxa distribution, role and density of microbial habitants, hence highlighting individual phenotyping (physiological traits) and their relationship with gut dysbiosis, inflammation processes, metabolic disorders (pathological conditions). Synergic meta-omics or "systems biology"-based approaches may concur in providing advanced information on microbiota establishment and pathogen control. During early-life stages this massive amount of data may provide gut microbiota descriptive and functional charts which can be exploited to perform a good practice in childcare and pediatrics, thus providing nutraceutical benefits and endorsing healthy development and aging. This article is part of a Special Issue entitled: Translational Proteomics.

Estrogens have been postulated to exert a detrimental effect on spermatogenesis in vivo. Since mouse male germ cells express estrogen receptors, we have investigated whether molecular pathways are activated by estrogen stimulation of these cells. Our results demonstrate that estrogen receptor beta is expressed in mitotic and meiotic male germ cells as well as in the spermatogonia derived GC-1 cell line. By using this cell line, we show that 17-beta-estradiol triggers activation of a transcriptional response that requires a functional estrogen receptor. Moreover, GC-1 cells respond to estrogens by transiently activating a signal transduction pathway that impinges on the mitogen-activated protein kinases (MAPK) ERK1 and -2. A similar dose-dependent transient activation of ERKs was also observed in primary mouse spermatocytes in culture. Activation by the estrogen was specific because other steroids such as progesterone and dihydrotestosterone were ineffective and because it could be blocked by the selective inhibitor of the ERK pathway and by competitive inhibitors of the estrogen receptor. Finally, we observed that 17-beta-estradiol does not affect spontaneous or induced apoptosis in cultured mouse spermatocytes, indicating that the apoptotic effects observed in vivo require additional testicular components.

Transient hypogammaglobulinemia of infancy (THI) is a heterogeneous disorder characterized by reduced serum IgG levels in early infancy. A putative diagnosis is initially made after exclusion of other causes of hypogammaglobulinemia while a definitive diagnosis of THI can only be made a posteriori in patients with normalization of IgG levels. The aim of this study is to characterize clinical and immunological features of children with an initial diagnosis of THI in correlation to natural outcome, and to assess predictive laboratory parameters of clinical evolution for this disorder. We prospectively analysed clinical and immunological characteristics of 77 THI children at initial diagnosis and of 57 patients at follow-up. Memory B cell subsets and in vitro immunoglobulin production were evaluated. Seventy patients (91 percent) showed clinical symptoms. Patients suffered from infections (91 percent), allergies (47 percent) and autoimmune disease (4 percent). During follow-up 41/57 children (72 percent) normalized IgG values, mostly within 24 months of age (p less than 0.001), allowing the diagnosis of THI. The 16 children who did not normalize their IgG levels showed a higher frequency of severe infections and autoimmune disease (p less than 0.01). Moreover, they expressed a reduced frequency of IgM and switched memory B cells (p less than 0.01) and an inability to produce IgG in vitro (p less than 0.02). We conclude that most patients with an initial diagnosis of THI spontaneously recover within 24 months of age and have a benign clinical course, while a subgroup of children with undefined hypogammaglobulinemia share a clinical and immunological profile with other primary immunodeficiencies. Early recognition of children with hypogammaglobulinemia during infancy who are likely to suffer from permanent immunodeficiencies later in life would allow prompt and appropriate laboratory and clinical interventions.