Distribution of Primed T Cells and Antigen-Loaded Antigen Presenting Cells Following Intranasal Immunization in Mice

Priming of T cells is a key event in vaccination, since it bears a decisive influence on the type and magnitude of the immune response. T-cell priming after mucosal immunization via the nasal route was studied by investigating the distribution of antigen-loaded antigen presenting cells (APCs) and primed antigen-specific T cells. Nasal immunization studies were conducted using the model protein antigen ovalbumin (OVA) plus CpG oligodeoxynucleotide adjuvant. Trafficking of antigen-specific primed T cells was analyzed in vivo after adoptive transfer of OVA-specific transgenic T cells in the presence or absence of fingolimod, a drug that causes lymphocytes sequestration within lymph nodes. Antigen-loaded APCs were observed in mediastinal lymph nodes, draining the respiratory tract, but not in distal lymph nodes. Antigen-specific proliferating T cells were first observed within draining lymph nodes, and later in distal iliac and mesenteric lymph nodes and in the spleen. The presence at distal sites was due to migration of locally primed T cells as shown by fingolimod treatment that caused a drastic reduction of proliferated T cells in non-draining lymph nodes and an accumulation of extensively divided T cells within draining lymph nodes. Homing of nasally primed T cells in distal iliac lymph nodes was CD62L-dependent, while entry into mesenteric lymph nodes depended on both CD62L and α4β7, as shown by in vivo antibody-mediated inhibition of T-cell trafficking. These data, elucidating the trafficking of antigen-specific primed T cells to non-draining peripheral and mucosa-associated lymph nodes following nasal immunization, provide relevant insights for the design of vaccination strategies based on mucosal priming

Enterococcus hirae Mitral Valve Infectious Endocarditis: A Case Report and Review of the Literature

Enterococcus hirae is a rare pathogen in human infections, although its incidence may be underestimated due to its difficult isolation. We describe the first known case of E. hirae infective endocarditis (IE), which involves the mitral valve alone, and the seventh E. hirae IE worldwide. Case presentation: a 62-year-old male was admitted to our department with a five-month history of intermittent fever without responding to antibiotic treatment. His medical history included mitral valve prolapse, recent pleurisy, and lumbar epidural steroid injections due to lumbar degenerative disc disease. Pre-admission transesophageal echocardiography (TEE) showed mitral valve vegetation, and Enterococcus faecium was isolated on blood cultures by MALDI-TOF VITEK MS. During hospitalization, intravenous (IV) therapy with ampicillin and ceftriaxone was initiated, and E. hirae was identified by MALDI-TOF Bruker Biotyper on three blood culture sets. A second TEE revealed mitral valve regurgitation, which worsened due to infection progression. The patient underwent mitral valve replacement with a bioprosthetic valve and had an uncomplicated postoperative course; he was discharged after six weeks of IV ampicillin and ceftriaxone treatment

Immunization with the conjugate vaccine Vi-CRM197 against Salmonella Typhi induces Vi-specific mucosal and systemic immune responses in mice

AbstractTyphoid fever is a public health problem, especially among young children in developing countries. To address this need, a glycoconjugate vaccine Vi-CRM197, composed of the polysaccharide antigen Vi covalently conjugated to the non-toxic mutant of diphtheria toxin CRM197, is under development. Here, we assessed the antibody and cellular responses, both local and systemic, following subcutaneous injection of Vi-CRM197. The glycoconjugate elicited Vi-specific serum IgG titers significantly higher than unconjugated Vi, with prevalence of IgG1 that persisted for at least 60 days after immunization. Vi-specific IgG, but not IgA, were present in intestinal washes. Lymphocytes proliferation after restimulation with Vi-CRM197 was observed in spleen and mesenteric lymph nodes. These data confirm the immunogenicity of Vi-CRM197 and demonstrate that the vaccine-specific antibody and cellular immune responses are present also in the intestinal tract, thus strengthening the suitability of Vi-CRM197 as a promising candidate vaccine against Salmonella Typhi

Immunogenicity of a Bivalent Adjuvanted Glycoconjugate Vaccine against Salmonella Typhimurium and Salmonella Enteritidis

Salmonella enterica serovars Typhimurium and Enteritidis are the predominant causes of invasive non-typhoidal Salmonella (iNTS) disease. Considering the co-endemicity of S. Typhimurium and S. Enteritidis, a bivalent vaccine formulation against both pathogens is necessary for protection against iNTS disease, thus investigation of glycoconjugate combination is required. In the present work, we investigated the immune responses induced by S. Typhimurium and S. Enteritidis monovalent and bivalent glycoconjugate vaccines adjuvanted with aluminum hydroxide (alum) only or in combination with cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG). Humoral and cellular, systemic and local, immune responses were characterized in two different mouse strains. All conjugate vaccines elicited high levels of serum IgG against the respective O-antigens (OAg) with bactericidal activity. The bivalent conjugate vaccine induced systemic production of antibodies against both S. Typhimurium and S. Enteritidis OAg. The presence of alum or alum + CpG adjuvants in vaccine formulations significantly increased the serum antigen-specific antibody production. The alum + CpG bivalent vaccine formulation triggered the highest systemic anti-OAg antibodies and also a significant increase of anti-OAg IgG in intestinal washes and fecal samples, with a positive correlation with serum levels. These data demonstrate the ability of monovalent and bivalent conjugate vaccines against S. Typhimurium and S. Enteritidis to induce systemic and local immune responses in different mouse strains, and highlight the suitability of a bivalent glycoconjugate formulation, especially when adjuvanted with alum + CpG, as a promising candidate vaccine against iNTS disease

Sustainable and Health-Protecting Food Ingredients from Bioprocessed Food by-Products and Wastes

Dietary inadequacy and nutrition-related non-communicable diseases (N-NCDs) represent two main issues for the whole society, urgently requesting solutions from researchers, policy-makers, and other stakeholders involved in the health and food system. Food by-products and wastes (FBPW) represent a global problem of increasing severity, widely recognized as an important unsustainability hotspot, with high socio-economic and environmental costs. Yet, recycling and up-cycling of FBPW to produce functional foods could represent a solution to dietary inadequacy and risk of N-NCDs onset. Bioprocessing of FBPW with selected microorganisms appears to be a relatively cheap strategy to yield molecules (or rather molecules mixtures) that may be used to fortify/enrich food, as well as to formulate dietary supplements. This review, conjugating human health and sustainability in relation to food, describes the state-of-the-art of the use of yeasts, molds, and lactic acid bacteria for producing value-added compounds from FBPW. Challenges related to FBPW bioprocessing prior to their use in food regard will be also discussed: (i) loss of product functionality upon scale-up of recovery process; (ii) finding logistic solutions to the intrinsic perishability of the majority of FBPW; (iii) inserting up-cycling of FBPW in an appropriate legislative framework; (iv) increasing consumer acceptability of food and dietary supplements derived from FBPWThis research was funded by the project SYSTEMIC “an integrated approach to the challenge of sustainable food systems: adaptive and mitigatory strategies to address climate change and malnutrition”, Knowledge hub on Nutrition and Food Security, that has received funding from national research funding parties in Belgium (FWO), France (INRA), Germany (BLE), Italy (MIPAAF), Latvia (IZM), Norway (RCN), Portugal (FCT), and Spain (AEI) in a joint action of JPI HDHL, JPI-OCEANS and FACCE-JPI launched in 2019 under the ERA-NET ERAHDHL (n° 696295). Francisca Rodrigues (CEECIND/01886/2020) is thankful for her contract financed by FCT/MCTES—CEEC Individual 2020 Program Contractinfo:eu-repo/semantics/publishedVersio

Trajectory of Spike-Specific B Cells Elicited by Two Doses of BNT162b2 mRNA Vaccine

: The mRNA vaccines for SARS-CoV-2 have demonstrated efficacy and immunogenicity in the real-world setting. However, most of the research on vaccine immunogenicity has been centered on characterizing the antibody response, with limited exploration into the persistence of spike-specific memory B cells. Here we monitored the durability of the memory B cell response up to 9 months post-vaccination, and characterized the trajectory of spike-specific B cell phenotypes in healthy individuals who received two doses of the BNT162b2 vaccine. To profile the spike-specific B cell response, we applied the tSNE and Cytotree automated approaches. Spike-specific IgA+ and IgG+ plasmablasts and IgA+ activated cells were observed 7 days after the second dose and disappeared 3 months later, while subsets of spike-specific IgG+ resting memory B cells became predominant 9 months after vaccination, and they were capable of differentiating into spike-specific IgG secreting cells when restimulated in vitro. Other subsets of spike-specific B cells, such as IgM+ or unswitched IgM+IgD+ or IgG+ double negative/atypical cells, were also elicited by the BNT162b2 vaccine and persisted up to month 9. The analysis of circulating spike-specific IgG, IgA, and IgM was in line with the plasmablasts observed. The longitudinal analysis of the antigen-specific B cell response elicited by mRNA-based vaccines provides valuable insights into our understanding of the immunogenicity of this novel vaccine platform destined for future widespread use, and it can help in guiding future decisions and vaccination schedules

Analytic and Dynamic Secretory Profile of Patient-Derived Cytokine-Induced Killer Cells

Adoptive immunotherapy with cytokine induced killer (CIK) cells has shown antitumor activity against several kinds of cancer in preclinical models and clinical trials. CIK cells are a subset of ex vivo expanded T lymphocytes with T-NK phenotype and MHC-unrestricted antitumor activity. The literature provides scant information on cytokines, chemokines and growth factors secreted by CIK cells. Therefore, we investigated the secretory profile of CIK cells generated from tumor patients. The secretome analysis was performed at specific time points (d 1, d 14 and d 21) of CIK cell expansion. Mature CIK cells (d 21) produce a great variety of interleukins and secreted proteins that can be divided into three groups based on their secretion quantity: high (interleukin [IL]-13, regulated on activation normal T cell expressed and secreted [RANTES] chemokine, MIP-1 alpha and 1 beta), medium (IL-1Ra, IL-5, IL-8, IL-10, IL-17, IP-10, INF-gamma, vascular endothelial growth factor [VEGF] and granulocyte-macrophage colony-stimulating factor [GM-CSF]) and low (IL-1 beta, IL-4, IL-6, IL-7, IL-9, IL-12, IL-15, eotaxin, platelet-derived growth factor-bb, basic fibroblast growth factor, G-CSF and monocyte chemoattractant protein [MCP]-1). Moreover, comparing peripheral blood mononuclear cells (PBMCs) (d 1) and mature CIK cells (d 14 and 21) secretomes, we observed that IL-5, IL-10, IL-13, GM-CSF and VEGF were greatly upregulated, while IL-1 beta, IL-6, IL-8, IL-15, IL-17, eotaxin, MCP-1 and RANTES were downregulated. We also performed a gene expression profile analysis of patient-derived CIK cells, showing that mRNA for the different cytokines and secreted proteins was modulated during PBMC-to-CIK differentiation. We highlight previously unknown secretory properties and provide, for the first time, a comprehensive molecular characterization of CIK cells. Our findings provide a rationale to explore the functional implications and possible therapeutic modulation of CIK secretome

B cell response after SARS-CoV-2 mRNA vaccination in people living with HIV

Background: Limited longitudinal data are available on immune response to mRNA SARS-CoV-2 vaccination in people living with HIV (PLWHIV); therefore, new evidence on induction and persistence of spike-specific antibodies and B cells is needed. Methods: In this pilot study we investigated the spike-specific humoral and B cell responses up to six months after vaccination with two doses of mRNA vaccines in 84 PLWHIV under antiretroviral therapy compared to 79 healthy controls (HCs). Results: Spike-specific IgG persisted six months in PLWHIV with no significant differences compared to HCs, even though a significantly lower IgG response was observed in patients with CD4+ T cells < 350/mmc. The frequency of subjects with antibodies capable of inhibiting ACE2/RBD binding was comparable between PLWHIV and HCs a month after the second vaccine dose, then a higher drop was observed in PLWHIV. A comparable percentage of spike-specific memory B cells was observed at month six in PLWHIV and HCs. However, PLWHIV showed a higher frequency of spike-specific IgD- CD27- double-negative memory B cells and a significantly lower rate of IgD- CD27+ Ig-switched memory B cells compared to HCs, suggesting a reduced functionality of the antigen-specific memory B population. Conclusions: The mRNA vaccination against SARS-CoV-2 elicits humoral and B cell responses quantitatively similar between PLWHIV and HCs, but there are important differences in terms of antibody functionality and phenotypes of memory B cells, reinforcing the notion that tailored vaccination policies should be considered for these patients

Characteristics, comorbidities and laboratory measures associated with disease severity and poor prognosis in young and elderly patients with COVID-19 admitted to medical wards in Emilia-Romagna region, Italy: a multicentre retrospective study

Background and Objectives. A relatively small number of studies have investigated the characteristics, comorbidities and laboratory measures associated with prognosis in patients with COVID-19, admitted to Internal Medicine Units (IMU) in Italy. Therefore, we performed a retrospective multicentre study to identify baseline features, predisposing to severe disease and poor outcomes, in adult individuals with SARS-CoV2 infection, hospitalized in 5 IMUs in the Emilia-Romagna region (Italy). Materials and Methods. We included 129 consecutive patients (male 75, median age 68 years) from 1st March 2020 to 31st October 2021. Patients' baseline characteristics, comorbidities, laboratory measures, and outcomes were collected. Results. At admission, the factors significantly associated with a higher risk of in-hospital mortality included: age (median 68 vs. 83 years in survived vs. dead patients, P=0.000), diabetes [Odds Ratio (OR) 4.00, P=0.016], chronic obstructive pulmonary disease (OR 4.60, P=0.022), cancer (OR 5.81, P=0.021), acute- (OR 9.88, P=0.000) and chronicrenal failure (OR 6.76, P=0.004). During the study period, 16 individuals died (12.4%), all over 70 years old. In deceased vs. non-deceased patients were detected: i) more elevated white blood cells and neutrophils-counts and lower lymphocytes count; ii) higher levels of total/direct bilirubin, creatinine, C-reactive-protein, lactate-dehydrogenase, ferritin, but only a slight Interleukin-6 increase; iii) a trend of lower vitamin D values. Conclusions. We proposed a new I index, a modified form of the Age-Adjusted Charlson Comorbidity Index, by considering pO(2)/FiO(2) ratio, to better characterize the severity of COVID-19. Furthermore, we critically discuss our results with the current assumption which considers COVID-19 as a pathological condition associated with cytokine storm

Heterologous Prime-Boost Combinations Highlight the Crucial Role of Adjuvant in Priming the Immune System

The induction and modulation of the immune response to vaccination can be rationally designed by combining different vaccine formulations for priming and boosting. Here, we investigated the impact of heterologous prime-boost approaches on the vaccine-specific cellular and humoral responses specific for a mycobacterial vaccine antigen. C57BL/6 mice were primed with the chimeric vaccine antigen H56 administered alone or with the CAF01 adjuvant, and boosted with H56 alone, or combined with CAF01 or with the squalene-based oil-in-water emulsion adjuvant (o/w squalene). A strong secondary H56-specific CD4+ T cell response was recalled by all the booster vaccine formulations when mice had been primed with H56 and CAF01, but not with H56 alone. The polyfunctional nature of T helper cells was analyzed and visualized with the multidimensional flow cytometry FlowSOM software, implemented as a package of the R environment. A similar cytokine profile was detected in groups primed with H56 + CAF01 and boosted with or without adjuvant, except for some clusters of cells expressing high level of IL-17 together with TNF-α, IL-2, and IFN-γ, that were significantly upregulated only in groups boosted with the adjuvants. On the contrary, the comparison between groups primed with or without the adjuvant showed a completely different clusterization of cells, strengthening the impact of the formulation used for primary immunization on the profiling of responding cells. The presence of the CAF01 adjuvant in the priming formulation deeply affected also the secondary humoral response, especially in groups boosted with H56 alone or o/w squalene. In conclusion, the presence of CAF01 adjuvant in the primary immunization is crucial for promoting primary T and B cell responses that can be efficiently reactivated by booster immunization also performed with antigen alone