Characterization of adolescents with functional respiratory disorders and prior history of SARS-CoV-2

BACKGROUND

The SARS-CoV-2 pandemic has caused significant pulmonary morbidity and mortality in the adult population. Children and adolescents typically show milder symptoms; however, a relevant proportion of them report persistent pulmonary symptoms even after mild SARS-CoV-2 infection. Functional respiratory disorders may be relevant differential diagnoses of persistent dyspnea. This study aims at characterizing functional respiratory disorders that may arise after SARS-CoV-2 infection regarding their clinical presentation and pulmonary function tests as well as gaining insights into the clinical course after initiation of appropriate therapy.

METHODS

This study retrospectively identified all patients referred to an outpatient clinic for pediatric pulmonology with functional respiratory disorders manifesting after proven SARS-CoV-2 infection between January 1, 2022, and October 31, 2022. Clinical history, thorough clinical examination regarding breathing patterns, and pulmonary function tests (PFTs) were taken into consideration to diagnose functional respiratory disorders.

RESULTS

Twenty-five patients (44% female) with mean (m) age = 12.73 years (SD ± 1.86) who showed distinctive features of functional respiratory disorders after SARS-CoV-2 infection (onset at m = 4.15 (± 4.24) weeks after infection) were identified. Eleven patients showed thoracic dominant breathing with insufficient ventilation, and 4 patients mainly had symptoms of inducible laryngeal obstruction. The rest (n = 10) showed overlap of these two etiologies. Most patients had a flattened inspiratory curve on spirometry and slightly elevated residual volume on body plethysmography, but values of PFTs were normal before and after standardized treadmill exercise testing. Patients were educated about the benign nature of the condition and were offered rebreathing training. All patients with follow-up (n = 5) showed normalization of the breathing pattern within 3 months.

CONCLUSIONS

Functional respiratory disorders are important differential diagnoses in persisting post-SARS-CoV-2 dyspnea in adolescents. A combination of clinical history, detailed examination of breathing patterns, and pulmonary function tests are helpful to correctly diagnose these conditions. Reassurance and rebreathing training are the mainstay of the therapy. The clinical course is favorable.

Phorbol-12-myristate-13-acetate is a potent enhancer of B cells with a granzyme B+ regulatory phenotype

Introduction

The infusion of ex-vivo-generated regulatory B cells may represent a promising novel therapeutic approach for a variety of autoimmune and hyperinflammatory conditions including graft-versus-host disease.

Methods

Previously, we developed a protocol for the generation of a novel population of regulatory B cells, which are characterized by secretion of enzymatically active granzyme B (GraB cells). This protocol uses recombinant interleukin 21 (IL-21) and goat-derived F(ab)'2 fragments against the human B cell receptor (anti-BCR). Generally, the use of xenogeneic material for the manufacturing of advanced therapy medicinal products should be avoided to prevent adverse immune reactions as well as potential transmission of so far unknown diseases.

Results

In the present work we demonstrated that phorbol-12-myristate-13-acetate (PMA/TPA), a phorbol ester with a particular analogy to the second messenger diacylglycerol (DAG), is a potent enhancer of IL-21-induced differentiation of pre-activated B cells into GraB cells. The percentage of GraB cells after stimulation of pre-activated B cells with IL-21 and PMA/TPA was not significantly lower compared to stimulation with IL-21 and anti-BCR.

Discussion

Given that PMA/TPA has already undergone encouraging clinical testing in patients with certain haematological diseases, our results suggest that PMA/TPA may be a safe and feasible alternative for ex-vivo manufacturing of GraB cells.

Multimodal analysis of granulocytes, monocytes, and platelets in patients with cystic fibrosis before and after Elexacaftor-Tezacaftor-Ivacaftor treatment

Cystic fibrosis (CF) is a monogenetic disease caused by an impairment of the cystic fibrosis transmembrane conductance regulator (CFTR). CF affects multiple organs and is associated with acute and chronic inflammation. In 2020, Elexacaftor-Tezacaftor-Ivacaftor (ETI) was approved to enhance and restore the remaining CFTR functionality. This study investigates cellular innate immunity, with a focus on neutrophil activation and phenotype, comparing healthy volunteers with patients with CF before (T1, n = 13) and after six months (T2, n = 11) of ETI treatment. ETI treatment reduced sweat chloride (T1: 95 mmol/l (83|108) vs. T2: 32 mmol/l (25|62), p < 0.01, median, first|third quartile) and significantly improved pulmonal function (FEV₁ T1: 2.66 l (1.92|3.04) vs. T2: 3.69 l (3.00|4.03), p < 0.01). Moreover, there was a significant decrease in the biomarker human epididymis protein 4 (T1: 6.2 ng/ml (4.6|6.3) vs. T2: 3.0 ng/ml (2.2|3.7), p < 0.01) and a small but significant decrease in matrix metallopeptidase 9 (T1: 45.5 ng/ml (32.5|140.1) vs. T2: 28.2 ng/ml (18.2|33.6), p < 0.05). Neutrophil phenotype (CD10, CD11b, CD62L, and CD66b) and function (radical oxygen species generation, chemotactic and phagocytic activity) remained largely unaffected by ETI treatment. Likewise, monocyte phenotype and markers of platelet activation were similar at T1 and T2. In summary, the present study confirmed a positive impact on patients with CF after ETI treatment. However, neither beneficial nor harmful effects of ETI treatment on cellular innate immunity could be detected, possibly due to the study population consisting of patients with well-controlled CF.

Effects of CFTR-modulator triple therapy on sinunasal symptoms in children and adults with cystic fibrosis

PURPOSE

Sinunasal symptoms and chronic rhinusinutitis are common in patients with cystic fibrosis. Cystic fibrosis transmembrane regulator (CFTR) modulators have led to dramatic improvements of respiratory symptoms and quality of life in patients with cystic fibrosis. This study aims to evaluate subjective and objective sinunasal symptoms after start of CFTR-modulator triple therapy.

METHODS

43 patients (n = 6 < 18 years), treated with highly effective CFTR-modulator therapy with elexacaftor-tezacaftor-ivacaftor (ELX/TEZ/IVA) were included, as were 20 controls with cystic fibrosis but without CFTR-modulator therapy (n = 6 < 18 years). All assessed their sinunasal symptoms retrospectively and the intervention group at a mean of 9.3 (2-16) months after start of ELX/TEZ/IVA.

RESULTS

Improvements in SNOT-22 overall score from m = 32.7 to m = 15.7 points (p < 0.0001) as well in the nasal, emotional, otologic, and sleep subdomains could be demonstrated in the intervention group. No changes were found in the control group. Children showed lower SNOT-22 scores than adults and a reduction of SNOT-22 total score from m = 9.4 to m = 2.2 (p = 0.25) was found. 8 patients were evaluated by an otorhinolaryngologist before and after start of ELX/TEZ/IVA and showed pronounced objective clinical improvement.

CONCLUSIONS

Highly effective CFTR-modulator therapy has a significant positive impact on both subjective and objective sinunasal symptoms in patients with CF and some improvement could be demonstrated in children < 18 years as well.

Serum neutralizing capacity and T-cell response against the omicron BA.1 variant in seropositive children and their parents one year after SARS-CoV-2 infection

Introduction

Durability of immune protection against reinfection with SARS-CoV-2 remains enigmatic, especially in the pediatric population and in the context of immune-evading variants of concern. Obviously, this knowledge is required for measures to contain the spread of infection and in selecting rational preventive measures.

Methods

Here, we investigated the serum neutralization capacity of 36 seropositive adults and 34 children approximately one year after infection with the ancestral Wuhan strain of SARS-CoV-2 by using a pseudovirus neutralization assay.

Results

We found that 88.9% of seropositive adult (32/36) and 94.1% of seropositive children (32/34) convalescents retained the neutralizing activity against the SARS-CoV-2 Wuhan strain (WT). Although, the neutralization effect against Omicron BA.1 (B.1.1.529.1) was significantly lower, 70.6% (24/34) of children and 41.7% (15/36) of adults possessed BA.1 cross-neutralizing antibodies. The spike 1 (S1)-specific T cell recall capacity using an activation-induced marker assay was analyzed in 18 adults and 16 children. All participants had detectable S1-specific CD4 T cells against WT, and 72.2% (13/18) adults and 81,3% (13/16) children had detectable S1 WT-specific CD8 T cells. CD4 cross-reactivity against BA.1 was demonstrated in all investigated adults (18/18), and 66.7% (12/18) adult participants had also detectable specific CD8 BA.1 T cells while we detected BA.1 S1 reactive CD4 and CD8 T cells in 81.3% (13/16) children.

Discussion

Together, our findings demonstrate that infection with the ancestral strain of SARS-CoV-2 in children as well as in adults induces robust serological as well as T cell memory responses that persist over at least 12 months. This suggests persistent immunological memory and partial cross-reactivity against Omicron BA.1.

Differentially induced immunity in buccal and nasal mucosae after vaccination for SARS–CoV–2: Prospects for mass scale immunity-screening in large populations

Introduction

Humoral immunity after SARS-CoV-2 vaccination has been extensively investigated in blood. Aim of this study was to develop an ELISA method in order to determine the prevalence of IgG and IgA SARS-CoV-2 domain 1 spike-protein (S) specific antibodies (Abs) in buccal and nasal mucosal surfaces of vaccinees.

Methods

To this end, we analyzed 69 individuals who received their first vaccine dose between February and July 2021. Vaccines administered were BNT162b2, mRNA-1273 or ChAdOx1-nCoV-19. Detection of IgG and IgA Abs was performed using commercial ELISA kits for both blood and swab samples after protocol modification for the latter.

Results

Anti-spike IgG and IgA Abs in the buccal and/or nasal swabs were detectable in &gt;81% of the study subjects after the second dose. The IgG measurements in buccal swabs appeared to correlate in a more consistent way with the respective measurements in blood with a correlation coefficient of r=0.74. It is of note that IgA Abs appeared to be significantly more prevalent in the nasal compared to the buccal mucosa. Optimal selection of the assay cut-off for the IgG antibody detection in buccal swabs conferred a sensitivity of 91.8% and a specificity of 100%. Last, individuals vaccinated with mRNA-based vaccines exhibited higher antibody levels in both blood and mucosal surfaces compared to those receiving ChAdOx1-nCoV-19 confirming previously reported results.

Conclusion

In conclusion, our findings show a differential prevalence of anti-S Abs on mucosal surfaces after vaccination for SARS-CoV-2, while they also set the basis for potential future use of IgG antibody detection in buccal swabs for extended immunity screening in large populations.

Long COVID symptoms in exposed and infected children, adolescents and their parents one year after SARS-CoV-2 infection: A prospective observational cohort study

Background

Long COVID in children and adolescents remains poorly understood due to a lack of well-controlled studies with long-term follow-up. In particular, the impact of the family context on persistent symptoms following SARS-CoV-2 infection remains unknown. We examined long COVID symptoms in a cohort of infected children, adolescents, and adults and their exposed but non-infected household members approximately 1 year after infection and investigated clustering of persistent symptoms within households.

Methods

1267 members of 341 households (404 children aged <14 years, 140 adolescents aged 14-18 years and 723 adults) were categorized as having had either a SARS-CoV-2 infection or household exposure to SARS-CoV-2 without infection, based on three serological assays and history of laboratory-confirmed infection. Participants completed questionnaires assessing the presence of long COVID symptoms 11-12 months after infection in the household using online questionnaires.

Findings

The prevalence of moderate or severe persistent symptoms was statistically significantly higher in infected than in exposed women (36.4% [95% CI: 30.7–42.4%] vs 14.2% [95% CI: 8.7–21.5%]), infected men (22.9% [95% CI: 17.9–28.5%] vs 10.3% [95% CI: 5.8–16.9%]) and infected adolescent girls (32.1% 95% CI: 17.2–50.5%] vs 8.9% [95%CI: 3.1–19.8%]). However, moderate or severe persistent symptoms were not statistically more common in infected adolescent boys aged 14–18 (9.7% [95% CI: 2.8–23.6%] or in infected children <14 years (girls: 4.3% [95% CI: 1.2–11.0%]; boys: 3.7% [95% CI: 1.1–9.6%]) than in their exposed counterparts (adolescent boys: 0.0% [95% CI: 0.0–6.7%]; girls < 14 years: 2.3% [95% CI: 0·7–6·1%]; boys < 14 years: 0.0% [95% CI: 0.0–2.0%]). The number of persistent symptoms reported by individuals was associated with the number of persistent symptoms reported by their household members (IRR=1·11, p=·005, 95% CI [1.03–1.20]).

Interpretation

In this controlled, multi-centre study, infected men, women and adolescent girls were at increased risk of negative outcomes 11-12 months after SARS-CoV-2 infection. Amongst non-infected adults, prevalence of negative outcomes was also high. Prolonged symptoms tended to cluster within families, suggesting family-level interventions for long COVID could prove useful.

Funding

Ministry of Science, Research and the Arts, Baden-Württemberg, Germany.

Short‐term effects of a novel bronchial drainage device: A pilot cohort study in subjects with cystic fibrosis

Background and Aims

Methods

Results

Conclusion

BNT162b2 Booster Vaccination Elicits Cross-Reactive Immunity Against SARS-CoV-2 Variants B.1.1.529 and B.1.617.2 in Convalescents of All Ages

In this prospective observational cohort study we analyzed cellular and serological immune response parameters against SARS-CoV-2 and current variants of concern (VOC) in 147 COVID-19-convalescent and 39 COVID-19-naïve individuals before and after BNT162b2 booster vaccination. No significant differences regarding immunological response parameters were observed between younger and older individuals. Booster vaccination induced full recovery of both cellular and serological response parameters including IFN-γ secretion and anti-spike antibody titers with strong neutralization capacities against wild type SARS-COV-2 and Delta. Surprisingly, even serological neutralization capacity against Omicron was detectable one month after second vaccination and four months before it had been first observed in South Africa. As a result, more than 90% of convalescent individuals exhibited detectable and 75% strong Omicron neutralization capacity after booster vaccination, compared with 72% and 46% of COVID-19-naïve individuals. Our results support the notion that broad and cross-reactive immune memory against SARS-CoV-2 including currently known VOCs can be established by booster vaccination with spike-based mRNA vaccines like BNT162b2, particularly in COVID-19-convalescent individuals of all ages. Nevertheless, especially in COVID-19-naïve individuals future variants escaping the memory immune response may require vaccine approaches such as inactivated whole virus vaccines, which include all antigenic components of the virus.

Role of ABO Blood Group in SARS-CoV-2 Infection in Households

An association between certain ABO/Rh blood groups and susceptibility to SARS-CoV-2 infection has been proposed for adults, although this remains controversial. In children and adolescents, the relationship is unclear due to a lack of robust data. Here, we investigated the association of ABO/Rh blood groups and SARS-CoV-2 in a multi-center study comprising 163 households with 281 children and 355 adults and at least one SARS-CoV-2 seropositive individual as determined by three independent assays as a proxy for previous infection. In line with previous findings, we found a higher frequency of blood group A (+ 6%) and a lower frequency of blood group O (−6%) among the SARS-CoV-2 seropositive adults compared to the seronegative ones. This trend was not seen in children. In contrast, SARS-CoV-2 seropositive children had a significantly lower frequency of Rh-positive blood groups. ABO compatibility did not seem to play a role in SARS-CoV-2 transmission within the families. A correction for family clusters was performed and estimated fixed effects of the blood group on the risk of SARS-CoV-2 seropositivity and symptomatic infection were determined. Although we found a different distribution of blood groups in seropositive individuals compared to the reference population, the risk of SARS-CoV-2 seropositivity or symptomatic infection was not increased in children or in adults with blood group A or AB versus O or B. Increasing age was the only parameter positively correlating with the risk of SARS-CoV-2 infection. In conclusion, specific ABO/Rh blood groups and ABO compatibility appear not to predispose for SARS-CoV-2 susceptibility in children.

Robust and durable serological response following pediatric SARS-CoV-2 infection

The quality and persistence of children's humoral immune response following SARS-CoV-2 infection remains largely unknown but will be crucial to guide pediatric SARS-CoV-2 vaccination programs. Here, we examine 548 children and 717 adults within 328 households with at least one member with a previous laboratory-confirmed SARS-CoV-2 infection. We assess serological response at 3-4 months and 11-12 months after infection using a bead-based multiplex immunoassay for 23 human coronavirus antigens including SARS-CoV-2 and its Variants of Concern (VOC) and endemic human coronaviruses (HCoVs), and additionally by three commercial SARS-CoV-2 antibody assays. Neutralization against wild type SARS-CoV-2 and the Delta VOC are analysed in a pseudotyped virus assay. Children, compared to adults, are five times more likely to be asymptomatic, and have higher specific antibody levels which persist longer (96.2% versus 82.9% still seropositive 11-12 months post infection). Of note, symptomatic and asymptomatic infections induce similar humoral responses in all age groups. SARS-CoV-2 infection occurs independent of HCoV serostatus. Neutralization responses of children and adults are similar, although neutralization is reduced for both against the Delta VOC. Overall, the long-term humoral immune response to SARS-CoV-2 infection in children is of longer duration than in adults even after asymptomatic infection.

Pulmonary Function and Persistent Clinical Symptoms in Children and Their Parents 12 Months After Mild SARS-CoV-2 Infection

BACKGROUND

Pulmonary involvement is the leading cause of morbidity and mortality after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Long-term impairment has been reported in adults with severe infection. However, most infections cause only mild symptoms or are even asymptomatic, especially in children. There is insufficient evidence regarding pulmonary outcome measures in mild SARS-CoV-2. The objectives of this study were to determine spirometry parameters after SARS-CoV-2 infection and correlate those with reported persisting symptoms in children, adolescents, and adults.

METHODS

Data on clinical symptoms during acute infection as well as SARS-CoV-2 serology results were recorded. Twelve months after infection, spirometry was performed and information on persisting symptoms was collected using a structured questionnaire. 182 participants (108 SARS-CoV-2 positive) from 48 families were included; 53 children (< 14 years), 34 adolescents and young adults (14-25 years), and 95 adults.

RESULTS

Spirometry values did not significantly differ between the particular subgroups of the cohort (adults, adolescents, children; infected and non-infected individuals). Adults reported more symptoms during acute infection as well more persisting fatigue (29.7% of participants), reduced physical resilience (34.4%), and dyspnea (25.0%) 12 months after infection than adolescents (fatigue 26.7%, reduced physical resilience 20%, and 0% dyspnea) and children (4%, 0%, 0%, respectively). There was no correlation between persistent subjective symptoms and spirometry results.

DISCUSSION

Children and adolescents are less affected than adults by acute SARS-CoV-2 as well as by post-infection persistent symptoms. Spirometry was not able to demonstrate any differences between healthy individuals and participants who had suffered from mild SARS-CoV-2 12 months after the infection.

Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 in Households with Children, Southwest Germany, May-August 2020

Resolving the role of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in households with members from different generations is crucial for containing the current pandemic. We conducted a large-scale, multicenter, cross-sectional seroepidemiologic household transmission study in southwest Germany during May 11-August 1, 2020. We included 1,625 study participants from 405 households that each had ≥1 child and 1 reverse transcription PCR-confirmed SARS-CoV-2-infected index case-patient. The overall secondary attack rate was 31.6% and was significantly higher in exposed adults (37.5%) than in children (24.6%-29.2%; p = <0.015); the rate was also significantly higher when the index case-patient was >60 years of age (72.9%; p = 0.039). Other risk factors for infectiousness of the index case-patient were SARS-CoV-2-seropositivity (odds ratio [OR] 27.8, 95% CI 8.26-93.5), fever (OR 1.93, 95% CI 1.14-3.31), and cough (OR 2.07, 95% CI 1.21-3.53). Secondary infections in household contacts generate a substantial disease burden.

Differential uptake of three clinically relevant allergens by human plasmacytoid dendritic cells

Background

Human plasmacytoid dendritic cells (pDC) have a dual role as interferon-producing and antigen-presenting cells. Their relevance for allergic diseases is controversial. and the impact of pDC on allergic immune responses is poorly understood.

Methods

This in vitro study on human pDC isolated from peripheral blood was designed to compare side by side the uptake of three clinically relevant representative allergens: fluorochrome-labeled house dust mite Der p 1, Bee venom extract from Apis mellifera (Api) and the food allergen OVA analyzed flow cytometry and confocal microscopy.

Results

We found that the internalization and its regulation by TLR9 ligation was significantly different between allergens in terms of time course and strength of uptake. Api and OVA uptake in pDC of healthy subjects was faster and reached higher levels than Der p 1 uptake. CpG ODN 2006 suppressed OVA uptake and to a lesser extent Der p 1, while Api internalization was not affected. All allergens colocalized with LAMP1 and EEA1, with Api being internalized particularly fast and reaching highest intracellular levels in pDC. Of note, we could not determine any specific differences in antigen uptake in allergic compared with healthy subjects.

Conclusions

To our knowledge this is the first study that directly compares uptake regulation of clinically relevant inhalative, injective and food allergens in pDC. Our findings may help to explain differences in the onset and severity of allergic reactions as well as in the efficiency of AIT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12948-021-00163-8.

BNT162b2 Vaccination Elicits Strong Serological Immune Responses Against SARS-CoV-2 Including Variants of Concern in Elderly Convalescents

Elderly residents of long-term care facilities (LTCFs) have long been underrepresented in studies on vaccine efficacy, particularly in light of currently emerging variants of concern (VOCs). In this prospective observational cohort study, we analyzed serological immune responses in 190 individuals before, 3 weeks after 1^st and 3 weeks after 2^nd vaccination with BNT162b2. Unvaccinated COVID-19-convalescent subjects served as reference. End points comprised serum anti-spike IgG and IgA titers as well as neutralization capacities against unmutated and mutated SARS-CoV-2 receptor binding domains including B.1.1.7, B.1.351 and P.1. We found that antibody titers and neutralization capacities up to 3 weeks after 2^nd vaccination with BNT162b2 were significantly higher in COVID-19-convalescent as compared to COVID-19-naive vaccinees. Moreover, pre-vaccination anti-NCP IgG titers, but not age or gender, had a high impact on the strength and kinetics of post-vaccination neutralization capacity development. Most importantly, BNT162b2-induced neutralization capacity was cross-reactive with VOCs. In contrast to unvaccinated convalescents, vaccinated convalescent individuals of all ages acquired strong neutralizing capacities against current VOCs. The present study suggests that COVID-19-convalescent individuals with a broad age range between 18 and 98 years benefit from BNT162b2 vaccination by developing strong and broad neutralizing immune responses against SARS-CoV-2 including current VOCs.

Diagnostic accuracy of MRI with MRCP and B-Mode-sonography with elastography of the pancreas in patients with cystic fibrosis: a point-to-point comparison

Objective

For patients with cystic fibrosis, the imaging of the pancreas is of crucial importance for the early detection of pancreatic carcinoma. Comparative studies between Magnetic Resonance Imaging (MRI) and sonographic pancreas sonography are not yet available. The aim of the study was to compare MRI, sonography and point-shearwave elastography (pSWE). A total of 19 patients were included (10 male, 9 female; age 29.7 ± 14.3 years) in the study. Ultrasonography with pSWE and contrast enhanced MRI with MRCP were performed.

Results

Significant differences between measurements of pancreatic body were registered in MRI with 1.4 ± 0.6 cm vs 1.0 ± 0.4 cm in ultrasound (p = 0.049), however not for pancreatic head and tail. In 10/19 patients (52.6%) pancreatic parenchyma did not show in MRI because of complete lipomatous transformation, but could be detected in ultrasound. pSWE-values showed no significant differences between the full and partial fatty transformation in pancreatic head (p = 0.968), body (p = 0.657) and tail (p = 0.840). pSWE-values did not correlate with measured signal intensity in T1w flash (p = 0.930, r = 0.025) and T2w HASTE sequences (p = 0.152, r = − 0.375). In patients with CF ultrasound is superior to MRI for displaying full fibro-fatty parenchymal transformation, pancreatic duct. Ultrasound elastography did not provide additional clinical relevant information.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4193-4) contains supplementary material, which is available to authorized users.

Point shear wave elastography of the pancreas in patients with cystic fibrosis: a comparison with healthy controls

PURPOSE

Manifestations of cystic fibrosis in the pancreas are gaining in clinical importance as patients live longer. Conventional ultrasonography and point shear wave elastography (pSWE) imaging are non-invasive and readily available diagnostic methods that are easy to perform. The aim of this study was to perform conventional ultrasonography and obtain pSWE values in the pancreases of patients with cystic fibrosis and to compare the findings with those of healthy controls.

METHODS

27 patients with cystic fibrosis (13 women/14 men; mean age 27.7 ± 13.7 years; range 9-58 years) and 60 healthy control subjects (30 women/30 men; mean age 30.3 ± 10.0 years; range 22-55 years) underwent examinations of the pancreas with conventional ultrasound and pSWE imaging.

RESULTS

Patients with cystic fibrosis have an echogenic pancreatic parenchyma. We found cystic lesions of the pancreas in six patients. pSWE imaging of the pancreatic parenchyma gave significantly lower shear wave velocities in patients with cystic fibrosis than in the control group (1.01 m/s vs 1.30 m/s; p < 0.001).

CONCLUSIONS

Using pSWE imaging in vivo, we have shown that the pancreas is considerably softer in patients with cystic fibrosis than in a healthy control population.

CD4+ T cell-derived IL-21 and deprivation of CD40 signaling favor the in vivo development of granzyme B-expressing regulatory B cells in HIV patients

IL-21 can induce both plasma cells and regulatory B cells. In this article, we demonstrate that untreated HIV patients display CD4(+) T cells with enhanced IL-21 expression and high in vivo frequencies of regulatory B cells overexpressing the serine protease granzyme B. Granzyme B-expressing regulatory B cells (GraB cells) cells from HIV patients exhibit increased expression of CD5, CD43, CD86, and CD147 but do not produce IL-10. The main functional characteristic of their regulatory activity is direct granzyme B-dependent degradation of the TCR-ζ-chain, resulting in significantly decreased proliferative T cell responses. Although Th cells from HIV patients secrete IL-21 in a Nef-dependent manner, they barely express CD40L. When culturing such IL-21(+)CD40L(-) Th cells with B cells, the former directly induce B cell differentiation into GraB cells. In contrast, the addition of soluble CD40L multimers to T cell/B cell cultures redirects B cell differentiation toward plasma cells, indicating that CD40L determines the direction of IL-21-dependent B cell differentiation. As proof of principle, we confirmed this mechanism in a patient lacking intact CD40 signaling due to a NEMO mutation. The majority of peripheral B cells from this patient were GraB cells and strongly suppressed T cell proliferation. In conclusion, GraB cells represent potent regulatory B cells in humans that are phenotypically and functionally distinct from B10 cells and occur in early HIV infection. GraB cells may contribute significantly to immune dysfunction in HIV patients, and may also explain ineffective Ab responses after vaccination. The use of soluble CD40L multimers may help to improve vaccination responses in HIV patients.

B-CLL cells acquire APC- and CTL-like phenotypic characteristics after stimulation with CpG ODN and IL-21

CpG oligodeoxynucleotides (CpG) and IL-21 are two promising agents for the treatment of B-cell chronic lymphocytic leukemia (B-CLL). Recently, we reported that the combination of CpG and IL-21 (CpG/IL-21) can induce granzyme B (GrB)-dependent apoptosis in B-CLL cells. Here, we demonstrate that treatment of B-CLL cells with CpG and IL-21 results in the development of antigen-presenting cell (APC)-like cells with cytotoxic features. These properties eventually give rise to B-CLL cell apoptosis, independently of their cytogenetic phenotype, whereas normal B-cell survival is not negatively affected by CpG/IL-21. APC- and CTL-typical molecules found to be up-regulated in CpG/IL-21-stimulated B-CLL cells include GrB, perforin, T-bet, monokine-induced by IFN-γ and IFN-γ-inducible protein 10 (IP-10), as well as molecules important for cell adhesion, antigen cross-presentation and costimulation. Also induced are molecules involved in GrB induction, trafficking and processing, whereas the GrB inhibitor Serpin B9 [formerly proteinase inhibitor-9 (PI-9)] is down-modulated by CpG/IL-21. In conclusion, CpG/IL-21-stimulated B-CLL cells acquire features that are reminiscent of killer dendritic cells, and which result in enhanced immunogenicity, cytotoxicity and apoptosis. Our results provide novel insights into the aberrant immune state of B-CLL cells and may establish a basis for the development of an innovative cellular vaccination approach in B-CLL.

Anti-viral vaccines license T cell responses by suppressing granzyme B levels in human plasmacytoid dendritic cells. (P4510)

Human plasmacytoid dendritic cells (pDC) are important modulators of adaptive T cell responses during viral infections. Recently, we found that human pDC produce the serine protease granzyme B (GrB), thereby regulating T cell proliferation in a GrB-dependent manner. Here, we demonstrate that intrinsic GrB production by pDC is significantly inhibited in vitro and in vivo by clinically used vaccines against viral infections such as tick-borne encephalitis (TBEV). We show that pDC GrB levels inversely correlate with the proliferative response of co-incubated T cells and that GrB suppression by a specific antibody or a GrB substrate inhibitor results in enhanced T cell proliferation, suggesting a predominant role of GrB in pDC-dependent T cell licensing. Functionally, we demonstrate that GrBhigh, but not GrBlow pDC transfer GrB to T cells, and may degrade the zeta-chain of the T cell receptor in a GrB-dependent fashion, thereby providing a possible explanation for the observed T cell suppression by GrB-expressing pDC. Modulation of pDC-derived GrB activity represents a previously unknown mechanism by which both anti-viral and vaccine-induced T cell responses may be regulated in vivo. Our results provide novel insights into pDC biology during vaccinations and may contribute to an improvement of prophylactic and therapeutic vaccines.

Interleukin-21-induced granzyme B-expressing B lymphocytes regulate T cells and infiltrate tumors (P1088)

The role of B cells in tumor infiltrations is controversially discussed. Different studies suggest that certain tumor-infiltrating B cell populations exhibit regulatory potential. Here, we demonstrate that the microenvironment of various solid tumors contains granzyme B (GrB)-expressing B cells adjacent to IL-21-providing T cells. Since GrB-mediated effector T cell modulation is known from regulatory T cells (Treg) and plasmacytoid dendritic cells, we hypothesized the existence of similar mechanisms in B cells. Here we show that IL-21 induces B cells expressing high levels of GrB and controlling T cell proliferation by GrB-dependent degradation of the T cell receptor ζ-chain. Detailed characterization of IL-21-induced GrB+ B cells reveals a CD19+CD38+CD1d+IgM+CD147+ phenotype and expression of additional regulatory molecules including IL-10, CD25 and IDO. Of note, IL-21-mediated GrB induction integrates both BCR- and TLR-mediated signals and is enhanced in the presence of B cell CD5 expression. This is the first report demonstrating that IL-21 induces GrB+ human regulatory B cells, which can be detected in tumor infiltrations, and which may contribute to the modulation of cellular adaptive immune responses by Treg-like mechanisms. Our findings may stimulate the development of novel diagnostic and cell therapeutic approaches to the management of malignant, autoimmune and graft-versus-host pathologies.

Interleukin 21-induced granzyme B-expressing B cells infiltrate tumors and regulate T cells

The pathogenic impact of tumor-infiltrating B cells is unresolved at present, however, some studies suggest that they may have immune regulatory potential. Here, we report that the microenvironment of various solid tumors includes B cells that express granzyme B (GrB, GZMB), where these B cells can be found adjacent to interleukin (IL)-21-secreting regulatory T cells (Treg) that contribute to immune tolerance of tumor antigens. Because Tregs and plasmacytoid dendritic cells are known to modulate T-effector cells by a GrB-dependent mechanism, we hypothesized that a similar process may operate to modulate regulatory B cells (Breg). IL-21 induced outgrowth of B cells expressing high levels of GrB, which thereby limited T-cell proliferation by a GrB-dependent degradation of the T-cell receptor ζ-chain. Mechanistic investigations into how IL-21 induced GrB expression in B cells to confer Breg function revealed a CD19(+)CD38(+)CD1d(+)IgM(+)CD147(+) expression signature, along with expression of additional key regulatory molecules including IL-10, CD25, and indoleamine-2,3-dioxygenase. Notably, induction of GrB by IL-21 integrated signals mediated by surface immunoglobulin M (B-cell receptor) and Toll-like receptors, each of which were enhanced with expression of the B-cell marker CD5. Our findings show for the first time that IL-21 induces GrB(+) human Bregs. They also establish the existence of human B cells with a regulatory phenotype in solid tumor infiltrates, where they may contribute to the suppression of antitumor immune responses. Together, these findings may stimulate novel diagnostic and cell therapeutic approaches to better manage human cancer as well as autoimmune and graft-versus-host pathologies.

Acute lymphoblastic leukemia cells treated with CpG oligodeoxynucleotides, IL-4 and CD40 ligand facilitate enhanced anti-leukemic CTL responses

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Although the majority of patients initially respond to upfront chemotherapy, relapses with poor prognosis occur in approximately 20% of cases. Thus, novel therapeutic strategies are required to improve long-term survival. B-cell precursor (BCP)-ALL cells express low levels of immunogenic molecules and, therefore, are poorly recognized by the immune system. In the present study, we investigated the effect of various combinations of potent B-cell stimulators including CpG, Interleukin (IL)-2 family cytokines and CD40 ligand (CD40L) on the immunogenicity of primary BCP-ALL cells and a series of BCP-ALL cell lines. The combination of CpG, IL-4 and CD40L was identified as most effective to enhance expression of immunogenic molecules on BCP-ALL cells, resulting in an increased capacity to induce both allogeneic and autologous cytotoxic T lymphocytes (CTL). Importantly, such CTL exhibited significant anti-leukemic cytotoxicity not only towards treated, but also towards untreated BCP-ALL cells. Our results demonstrate that the combination of CpG with other B-cell stimulators is more efficient than CpG alone in generating immunogenic BCP-ALL cells and anti-leukemic CTL. Our results may stimulate the development of novel adoptive T cell transfer approaches for the management of BCP-ALL.

Interleukin 21-activated B cells can kill tumor cells in a granzyme B-dependent manner (66.5)

Interleukin 21 (IL-21) is a promising cytokine for the treatment of tumors and infections. Recently, IL-21 was identified as an inducer of plasma cells when combined with CD40 ligand (CD40L). Using various immunological methods including FACS analysis, ELISA, ELISpot and fluorescence microscopy, we demonstrate here that in the absence of CD40L B cells (BC) rather differentiate into granzyme B (GzmB)-secreting cytotoxic cells instead of plasma cells. GzmB induction in BC requires IL-21 and BC receptor cross-linking, and is associated with phosphorylation of SYK, JAK1/3 and STAT1/3, signaling molecules which are also involved in the activation of CTL and NK cells. CD40L effectively suppresses GzmB in BC, suggesting that GzmB-secreting BC play a role early during inflammatory responses, before CD40L-expressing T cells are present. BC-derived GzmB is enzymatically active and induces apoptosis in tumor cell lines including HeLa cells and PC3 cells. Importantly, induction of apoptosis by GzmB-secreting B cells can be suppressed by neutralization of GzmB using the substrate inhibitor Ac-IEPD-CHO as well as a novel small molecule inhibitor of GzmB identified in our laboratory. Our data reveal a novel role of IL-21-activated BC, which involves GzmB secretion and cytotoxicity. Our findings may have implications for the understanding of tumor immunosurveillance and early anti-viral immune responses, and may open novel approaches for the immunotherapy of neoplastic and viral diseases.

CD5+ B cells from individuals with systemic lupus erythematosus express granzyme B

Recently, we reported that IL-21 induces granzyme B (GzmB) and GzmB-dependent apoptosis in malignant CD5(+) B cells from patients with chronic lymphocytic leukemia. Several autoimmune diseases (AD) are associated with enhanced frequencies of CD5(+) B cells. Since AD are also associated with elevated IL-21 and GzmB levels, we postulated a link between CD5(+) B cells, IL-21 and GzmB. Here, we demonstrate that IL-21 and GzmB serum levels are highly correlated in subjects with systemic lupus erythematosus (SLE) and that freshly isolated CD5(+) SLE B cells constitutively express GzmB. IL-21 directly induced GzmB expression and secretion by CD5(+) B cells from several AD and from cord blood in vitro, and the simultaneous presence of BCR stimulation strongly enhanced this process. Furthermore, IL-21 suppressed both viability and expansion of CD5(+) B cells from SLE individuals. In summary, our study may explain the elevated levels of IL-21 and GzmB in SLE and other AD. Moreover, our data suggest that IL-21 may have disease-modifying characteristics by inducing GzmB in CD5(+) B cells and by suppressing their expansion. Our results provide the rationale for further evaluation of the therapeutic potential of IL-21 in certain AD such as SLE.

Human B cells secrete granzyme B when recognizing viral antigens in the context of the acute phase cytokine IL-21

Human B cells are currently not known to produce the proapoptotic protease granzyme B (GrB) in physiological settings. We have discovered that BCR stimulation with either viral Ags or activating Abs in the context of the acute phase cytokine IL-21 can induce the secretion of substantial amounts of GrB by human B cells. Importantly, GrB response to viral Ags was significantly stronger in B cells from subjects recently vaccinated against the corresponding viruses as compared with unvaccinated subjects. GrB-secreting B cells featured a homogeneous CD19(+)CD20(+)CD27(-)CD38(-)IgD(-) phenotype, improved survival, and enhanced expression of costimulatory, Ag-presenting and cell-adhesion molecules. B cell-derived GrB was enzymatically active and its induction required the activation of similar signaling pathways as those in CTLs. Our findings suggest that GrB-secreting B cells support the early antiviral immune response against viruses with endosomal entry pathways, thereby counteracting overwhelming viral replication at the beginning of an infection until virus-specific T cells from draining lymph nodes arrive at the site of infection. Our data may also explain the elevated serum GrB levels found in the early phase of various viral diseases.

Human plasmacytoid dendritic cell function: inhibition of IFN-alpha secretion and modulation of immune phenotype by vasoactive intestinal peptide

Plasmacytoid dendritic cells (PDC) are considered the main sentinels against viral infections and play a major role in immune tolerance. Vasoactive intestinal peptide (VIP) is a potent immunomodulator, whose role in PDC function is unknown. The present study was designed to investigate whether human PDC express VIP receptors and whether VIP has immunological effects on PDC. Using real-time RT-PCR and immunofluorescence, we demonstrated that VIP receptors VPAC1 and VPAC2 are expressed on PDC. After culturing PDC with VIP and CpG oligodeoxynucleotides for 48 h, expression of surface molecules with significance for PDC-T cell interactions as well as IFN-alpha secretion were quantified using FACS analysis and ELISA, respectively. For functional assays, CFSE-stained CD4+ T cells were coincubated with differentially treated PDC. T cell proliferation and production of various cytokines were determined by FACS analysis and ELISA. VIP enhanced PDC expression of CD86, MHC II, and CCR7. In contrast, VIP inhibited PDC secretion of IFN-alpha and expression of Neuropilin-1 and MHC I. The potential of CpG oligodeoxynucleotide-activated PDC to induce proliferation of allogeneic CD4(+) T cells was impaired when VIP was present during activation. Furthermore, pretreatment of PDC with VIP resulted in a decrease of the IFN-gamma:IL-4 ratio in cocultured T cells, suggesting a modulation of the immune response toward Th2. Taken together, these results strongly suggest that VIP regulates the immunological function of human PDC. VIP may thus be involved in the modulation of immune responses to viral infections as well as in the maintenance of immune tolerance.

Induction of Stable Mixed Chimerism by Embryonic Stem Cells Requires Functional Fas/FasL Engagement

BACKGROUND

Recent data show the efficacy of embryonic stem cells (ESC) to engraft in allogeneic recipients without host pretreatment. This property is due to their low expression of major histocompatibility complex (MHC) class I antigens and lack of MHC class II expression. Here, we tested the hypothesis that the constitutive FasL expression by ESC is a requirement for their stable engraftment in allogeneic recipients.

METHODS

MRL and MRL-lpr/lpr mice (H-2k) were infused allogeneic 129SvJ RW-4 (H-2b) ESC without host preconditioning. The development of mixed chimerism was monitored over 100 days by flow cytometry.

RESULTS

Mixed chimerism was detectable by day 7. The amount of donor cells detected varied between 3-5.5% and were lymphoid, but nonmyeloid. Only 50% of lpr/lpr mice engrafted and lost donor cells by day 28 post-ESC infusion. In contrast, >80% wild type mice engrafted and maintained mixed chimerism up to day 100.

CONCLUSIONS

These data suggest a critical role for Fas-FasL engagement in ESC engraftment. We conclude that ESC may induce clonal deletion of alloreactive T cells by Fas-induced apoptosis in recipient T cells, protecting them from rejection. The data provide a rationale for improved protocols for the achievement of robust ESC-induced mixed chimerism.

[From the devil one is not even protected in heaven. Remarks on E. Reinke's report, "Sociotherapy with prisoners", (Psyche 10/1987)]

According to the author's critique, Reinke's article about the Frankfurt project for criminal offenders omits any genuine psychoanalytic reflection on the attributions of subject and object, culprit and victim, therapist and patient. Given this omission, these attributions cannot be incorporated or resolved within the intended process of change.