Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
Infection ; 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38366304

ABSTRACT

PURPOSE: In late 2022, a surge of severe S. pyogenes infections was reported in several European countries. This study assessed hospitalizations and disease severity of community-acquired bacterial infections with S. pyogenes, S. pneumoniae, N. meningitidis, and H. influenzae among children in North Rhine-Westphalia (NRW), Germany, during the last quarter of 2022 compared to long-term incidences. METHODS: Hospital cases due to bacterial infections between October and December 2022 were collected in a multicenter study (MC) from 59/62 (95%) children's hospitals in NRW and combined with surveillance data (2016-2023) from the national reference laboratories for streptococci, N. meningitidis, and H. influenzae. Overall and pathogen-specific incidence rates (IR) from January 2016 to March 2023 were estimated via capture-recapture analyses. Expected annual deaths from the studied pathogens were calculated from national death cause statistics. RESULTS: In the MC study, 153 cases with high overall disease severity were reported with pneumonia being most common (59%, n = 91). IRs of bacterial infections declined at the beginning of the COVID-19 pandemic and massively surged to unprecedented levels in late 2022 and early 2023 (overall hospitalizations 3.5-fold), with S. pyogenes and S. pneumoniae as main drivers (18-fold and threefold). Observed deaths during the study period exceeded the expected number for the entire year in NRW by far (7 vs. 0.9). DISCUSSION: The unprecedented peak of bacterial infections and deaths in late 2022 and early 2023 was caused mainly by S. pyogenes and S. pneumoniae. Improved precautionary measures are needed to attenuate future outbreaks.

2.
Neuropediatrics ; 55(2): 140-145, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37846133

ABSTRACT

Mitchell syndrome is a very rare genetic disorder due to a specific de novo gain-of-function variant in acyl-CoA oxidase 1 (ACOX1). So far, only five patients with this disease have been described worldwide. We present here two additional unrelated German patients found to carry the same heterozygous ACOX1 N237S variant through exome sequencing (ES). Both patients showed neurodegenerative clinical features starting from ∼4 to 5 years of age including progressive hearing loss, ataxia, ichthyosis, as well as progressive visual impairment leading to amaurosis, and died at the ages of 16 and 8 years, respectively. The first patient was clinically suspected to have anti-myelin oligodendrocyte glycoprotein-antibody-associated myelitis, but the disease course overall deteriorated despite extensive immunomodulatory therapy. The second patient was originally suspected to have a mitochondrial disorder due to intermittent elevated blood lactate. Since Mitchell syndrome has only been identified in 2020, the diagnosis in this second patient was only established through re-evaluation of ES data years after the original analysis. Comparison of all seven reported patients suggests that Mitchell syndrome often (but not always) clinically mimics autoimmune-inflammatory disease. Therefore, in patients with autoimmune central nervous system disease who do not respond adequately to standard therapies, re-evaluation of this diagnosis is needed and genetic analyses such as trio ES should be considered.


Subject(s)
Autoimmune Diseases , Gain of Function Mutation , Child , Humans , Myelin-Oligodendrocyte Glycoprotein , Vision Disorders
3.
Children (Basel) ; 10(12)2023 Dec 06.
Article in English | MEDLINE | ID: mdl-38136092

ABSTRACT

Given the crucial role of vaccination in halting the COVID-19 pandemic, it is imperative to understand the factors that motivate adolescents to get vaccinated. We surveyed adolescents and their accompanying guardians scheduled to receive a COVID-19 vaccination (Comirnaty) in an urban region in Germany in mid-2021 regarding their motivation for getting vaccinated and collected data on their sociodemographic characteristics, medical history, vaccination status, and any history of COVID-19 infection in the family. We also queried information strategies related to the SARS-CoV-2 pandemic. Motivations for getting vaccinated were similar among adolescents and their parents. The primary reasons for vaccination were protection against SARS-CoV-2-related illness and gaining access to leisure facilities. This was not influenced by gender, health status, migration background, or the presence of chronic or acute diseases. The percentage of parents who had received SARS-CoV-2 immunization and the proportion of parents with a high level of education were higher among study participants than in the general population. Adolescents were especially willing to be vaccinated if they came from a better educational environment and had a high vaccination rate in the family. Emphasizing the importance of vaccination among all segments of the population and removing barriers to vaccines may lead to an ameliorated acceptance of COVID-19 vaccines.

4.
Eur J Pediatr ; 182(7): 2999-3006, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37121990

ABSTRACT

The number of children with tracheostomies with and without home mechanical ventilation has grown continuously in recent years. For some of these children, the need for tracheostomy resolves and the child can be weaned from the tracheal cannula. Choosing the optimal time point for decannulation after elaborated prior diagnostic work-up needs careful consideration. The decannulation process requires an interdisciplinary team; however, these specialized structures for the experienced care of these children with tracheostomy are not available in all areas. The Working Group on Chronic Respiratory Insufficiency in the German Speaking Pediatric Pneumology Society (GPP) developed these recommendations to guide through a decannulation process. Initial evaluation of decannulation feasibility starts in the outpatient clinic with a detailed history, examination, and a speaking valve trial and is followed by an inpatient workup including sleep study, airway endoscopy and possibly modifications of the tracheal cannula. Downsizing the tracheal cannula allows a stepwise controlled weaning prior to removal of the tracheal cannula. After shrinking of the tracheostomy, the final surgical closure is performed.  Conclusion: An algorithm with diagnostic and therapeutic procedures for a safe and successful decannulation process is proposed. What is Known: • In children tracheostomy decannulation is a complex process that requires careful preparation and surveillance. What is New: • This statement of the German speaking society of pediatric pulmonology provides an expert practice guidance on the decannulation procedure and the value of one-way speaking valves.


Subject(s)
Pulmonary Medicine , Respiratory Insufficiency , Humans , Child , Tracheostomy/methods , Device Removal/methods , Respiratory Insufficiency/therapy , Respiration, Artificial/methods , Retrospective Studies
5.
J Clin Immunol ; 43(5): 965-978, 2023 07.
Article in English | MEDLINE | ID: mdl-36843153

ABSTRACT

BACKGR OUND: T-cell receptor excision circle (TREC)-based newborn screening (NBS) for severe combined immunodeficiencies (SCID) was introduced in Germany in August 2019. METHODS: Children with abnormal TREC-NBS were referred to a newly established network of Combined Immunodeficiency (CID) Clinics and Centers. The Working Group for Pediatric Immunology (API) and German Society for Newborn Screening (DGNS) performed 6-monthly surveys to assess the TREC-NBS process after 2.5 years. RESULTS: Among 1.9 million screened newborns, 88 patients with congenital T-cell lymphocytopenia were identified (25 SCID, 17 leaky SCID/Omenn syndrome (OS)/idiopathic T-cell lymphocytopenia, and 46 syndromic disorders). A genetic diagnosis was established in 88%. Twenty-six patients underwent hematopoietic stem cell transplantation (HSCT), 23/26 within 4 months of life. Of these, 25/26 (96%) were alive at last follow-up. Two patients presented with in utero onset OS and died after birth. Five patients with syndromic disorders underwent thymus transplantation. Eight syndromic patients deceased, all from non-immunological complications. TREC-NBS missed one patient, who later presented clinically, and one tracking failure occurred after an inconclusive screening result. CONCLUSION: The German TREC-NBS represents the largest European SCID screening at this point. The incidence of SCID/leaky SCID/OS in Germany is approximately 1:54,000, very similar to previous observations from North American and European regions and countries where TREC-NBS was implemented. The newly founded API-CID network facilitates tracking and treatment of identified patients. Short-term HSCT outcome was excellent, but NBS and transplant registries will remain essential to evaluate the long-term outcome and to compare results across the rising numbers of TREC-NBS programs across Europe.


Subject(s)
Lymphopenia , Severe Combined Immunodeficiency , Child , Infant, Newborn , Humans , Neonatal Screening/methods , Severe Combined Immunodeficiency/diagnosis , Severe Combined Immunodeficiency/epidemiology , Severe Combined Immunodeficiency/therapy , Prospective Studies , Lymphopenia/diagnosis , DNA , Germany/epidemiology , Receptors, Antigen, T-Cell/genetics
6.
Children (Basel) ; 9(11)2022 Nov 10.
Article in English | MEDLINE | ID: mdl-36360452

ABSTRACT

Studies in recent years and especially since the beginning of the COVID-19 pandemic have shown a significant increase in the problematic use of computer games and social media. Adolescents having difficulties in regulating their unpleasant emotions are especially prone to Problematic Internet Use (PIU), which is why emotion dysregulation has been considered a risk factor for PIU. The aim of the present study was to assess problematic internet use (PIU) in adolescents after the third wave (nearly 1.5 years after the onset in Europe) of the COVID-19 pandemic. In the German region of Siegen-Wittgenstein, all students 12 years and older from secondary-level schools, vocational schools and universities were offered a prioritized vaccination in August 2021 with an approved vaccine against COVID-19. In this context, the participants filled out the Short Compulsive Internet Use Scale (SCIUS) and two additional items to capture a possible change in digital media usage time and regulation of negative affect due to the COVID-19 pandemic. A multiple regression analysis was performed to identify predictors of PIU. The original sample consisted of 1477 participants, and after excluding invalid cases the final sample size amounted to 1268 adolescents aged 12-17 (x = 14.37 years, SD = 1.64). The average prevalence of PIU was 43.69%. Gender, age, digital media usage time and the intensity of negative emotions during the COVID-19 pandemic were all found to be significant predictors of PIU: female gender, increasing age, longer digital media usage time and higher intensity of negative emotions during the COVID-19 pandemic were associated with higher SCIUS total scores. This study found a very high prevalence of PIU among 12- to 17-year-olds for the period after the third wave of the COVID-19 pandemic, which has increased significantly compared to pre-pandemic prevalence rates. PIU is emerging as a serious problem among young people in the pandemic. Besides gender and age, pandemic-associated time of digital media use and emotion regulation have an impact on PIU, which provides starting points for preventive interventions.

7.
Children (Basel) ; 9(6)2022 May 25.
Article in English | MEDLINE | ID: mdl-35740717

ABSTRACT

Evaluations after the first and second waves of the COVID-19 pandemic in Germany showed an increase in mental health problems and a reduction in health-related quality of life (HRQoL). The aim of the study was to assess those aspects after the third wave of COVID-19 in adolescents who decided to receive a vaccination. In students aged 12-17 years recruited from schools in one German region, mental health (by the strengths and difficulties questionnaire, SDQ) and HRQoL (by KIDSCREEN-10) were assessed by both a self- and parental report. Data from 1412 adolescents (mean age 14.3 years, SD = 1.64) and 908 parents were collected. The mean self-reported HRQoL was T = 53.7 (SD = 11.2), significantly higher in boys than in girls and higher in younger (12-14 years) than in older (15-17 years) adolescents. In total, 18.7% of adolescents reported clinically relevant psychological symptoms, especially peer problems (23.5%), emotional problems (17.4%), and hyperactivity (17.1%). Comparing the present data to evaluations after the first and second waves of COVID-19, adolescents rated a higher HRQoL and reported less mental health problems after the third wave. After 1.5 years of living with the pandemic, adolescents have adapted to the changes in everyday life. Further, the relaxation of restrictions, better school organization, and the prospect of the vaccination may have increased optimism, wellbeing, and contentment, leading to declining but still alarming rates of psychological symptoms.

8.
Pediatrics ; 150(2)2022 08 01.
Article in English | MEDLINE | ID: mdl-35534988

ABSTRACT

BACKGROUND AND OBJECTIVES: The worldwide severe acute respiratory syndrome coronavirus 2 pandemic challenges adolescents' mental health. In this study, we aim to compare the number of pediatric ICU (PICU) admissions after suicide attempts during the first German lockdown and one year later during a second, prolonged lockdown with prepandemic years. METHODS: A retrospective multicenter study was conducted among 27 German PICUs. Cases <18 years admitted to the PICU because of accidents or injuries between March 16 and May 31 of 2017 to 2021 were identified based on International Classification of Diseases, 10th Revision codes (German modification) and patient data entered into a database. This study is a subset analysis on suicide attempts in adolescents aged 12 to 17.9 years. The Federal Statistics Office was queried for data on fatal suicides, which were available only for 2020 in adolescents aged 10 to 17.9 years. RESULTS: Total admissions and suicide attempts declined during the first lockdown in 2020 (standardized morbidity ratio 0.74 (95% confidence interval; 0.58-0.92) and 0.69 (0.43-1.04), respectively) and increased in 2021 (standardized morbidity ratio 2.14 [1.86-2.45] and 2.84 [2.29-3.49], respectively). Fatal suicide rates remained stable between 2017 to 2019 and 2020 (1.57 vs 1.48 per 100 000 adolescent years) with monthly numbers showing no clear trend during the course of 2020. CONCLUSIONS: This study shows a strong increase in serious suicide attempts among adolescents during the course of the pandemic in Germany. More research is needed to understand the relation between pandemic prevention measures and suicidal ideation to help implement mental health support for adolescents.


Subject(s)
COVID-19 , Suicide, Attempted , Adolescent , COVID-19/epidemiology , Child , Communicable Disease Control , Humans , Intensive Care Units, Pediatric , Pandemics , Suicidal Ideation
9.
Children (Basel) ; 9(3)2022 Mar 04.
Article in English | MEDLINE | ID: mdl-35327736

ABSTRACT

Children's and adolescents' lives drastically changed during COVID lockdowns worldwide. To compare accident- and injury-related admissions to pediatric intensive care units (PICU) during the first German COVID lockdown with previous years, we conducted a retrospective multicenter study among 37 PICUs (21.5% of German PICU capacities). A total of 1444 admissions after accidents or injuries during the first lockdown period and matched periods of 2017-2019 were reported and standardized morbidity ratios (SMR) were calculated. Total PICU admissions due to accidents/injuries declined from an average of 366 to 346 (SMR 0.95 (CI 0.85-1.05)). Admissions with trauma increased from 196 to 212 (1.07 (0.93-1.23). Traffic accidents and school/kindergarten accidents decreased (0.77 (0.57-1.02 and 0.26 (0.05-0.75)), whereas household and leisure accidents increased (1.33 (1.06-1.66) and 1.34 (1.06-1.67)). Less neurosurgeries and more visceral surgeries were performed (0.69 (0.38-1.16) and 2.09 (1.19-3.39)). Non-accidental non-suicidal injuries declined (0.73 (0.42-1.17)). Suicide attempts increased in adolescent boys (1.38 (0.51-3.02)), but decreased in adolescent girls (0.56 (0.32-0.79)). In summary, changed trauma mechanisms entailed different surgeries compared to previous years. We found no evidence for an increase in child abuse cases requiring intensive care. The increase in suicide attempts among boys demands investigation.

10.
N Engl J Med ; 385(24): 2264-2270, 2021 12 09.
Article in English | MEDLINE | ID: mdl-34881838

ABSTRACT

Inherited junctional epidermolysis bullosa is a severe genetic skin disease that leads to epidermal loss caused by structural and mechanical fragility of the integuments. There is no established cure for junctional epidermolysis bullosa. We previously reported that genetically corrected autologous epidermal cultures regenerated almost an entire, fully functional epidermis on a child who had a devastating form of junctional epidermolysis bullosa. We now report long-term clinical outcomes in this patient. (Funded by POR FESR 2014-2020 - Regione Emilia-Romagna and others.).


Subject(s)
Epidermis/transplantation , Epidermolysis Bullosa, Junctional/therapy , Keratinocytes/transplantation , Transduction, Genetic , Transgenes , Cell Self Renewal , Cells, Cultured/transplantation , Child , Clone Cells , Epidermis/pathology , Epidermolysis Bullosa, Junctional/genetics , Epidermolysis Bullosa, Junctional/pathology , Follow-Up Studies , Genetic Diseases, Inborn/pathology , Genetic Diseases, Inborn/therapy , Genetic Therapy , Genetic Vectors , Humans , Keratinocytes/cytology , Keratinocytes/physiology , Male , Regeneration , Stem Cells/physiology , Transplantation, Autologous
11.
Cell Rep ; 27(7): 2036-2049.e6, 2019 05 14.
Article in English | MEDLINE | ID: mdl-31091444

ABSTRACT

Laminin 332-deficient junctional epidermolysis bullosa (JEB) is a severe genetic skin disease. JEB is marked by epidermal stem cell depletion, the origin of which is unknown. We show that dysregulation of the YAP and TAZ pathway underpins such stem cell depletion. Laminin 332-mediated YAP activity sustains human epidermal stem cells, detected as holoclones. Ablation of YAP selectively depletes holoclones, while enforced YAP blocks conversion of stem cells into progenitors and indefinitely extends the keratinocyte lifespan. YAP is dramatically decreased in JEB keratinocytes, which contain only phosphorylated, inactive YAP. In normal keratinocytes, laminin 332 and α6ß4 ablation abolish YAP activity and recapitulate the JEB phenotype. In JEB keratinocytes, laminin 332-gene therapy rescues YAP activity and epidermal stem cells in vitro and in vivo. In JEB cells, enforced YAP recapitulates laminin 332-gene therapy, thus uncoupling adhesion from proliferation in epidermal stem cells. This work has important clinical implication for ex vivo gene therapy of JEB.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cell Adhesion Molecules , Epidermis/metabolism , Epidermolysis Bullosa , Genetic Therapy , Stem Cells/metabolism , Transcription Factors/metabolism , Adaptor Proteins, Signal Transducing/genetics , Animals , Cell Adhesion , Cell Adhesion Molecules/biosynthesis , Cell Adhesion Molecules/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line , Epidermis/pathology , Epidermolysis Bullosa/genetics , Epidermolysis Bullosa/metabolism , Epidermolysis Bullosa/pathology , Epidermolysis Bullosa/therapy , Humans , Keratinocytes/metabolism , Keratinocytes/pathology , Mice , Stem Cells/pathology , Transcription Factors/genetics , YAP-Signaling Proteins , Kalinin
12.
Clin Immunol ; 203: 125-133, 2019 06.
Article in English | MEDLINE | ID: mdl-31028919

ABSTRACT

Intestinal epithelial cells (IECs) form a fundamental mucosal barrier and actively participate in tolerance and immunity against intestinal contents. Major histocompatibility complex class II (MHC II) and invariant chain (Ii) molecules are essential for adaptive immune response. MHC II deficiency often presents with gastrointestinal disorders. Intestinal biopsy samples revealed an absence of HLA-DR, Ii, and local immunoglobulins in both hematopoietic immune cells and IECs accompanied by a lack of faecal sIgA. After successful hematopoietic stem cell transplantation (HSCT) absent HLA-DR and Ii expression persisted in IECs and faecal stool analysis indicated inflammation and high microbial activity. We describe multifaceted disturbance of adaptive mucosal immunity in MHC II deficient patients suffering from enteropathy. HLA-DR and Ii expression on enterocytes is not restored by HSCT. This may account for increased susceptibility to enteric infections and intestinal inflammation leading to prolonged enteropathy reported in MHC II deficient patients.


Subject(s)
Gastrointestinal Diseases/immunology , HLA-DR Antigens/genetics , Immunologic Deficiency Syndromes/immunology , Inflammation/immunology , Intestinal Mucosa/immunology , Adaptive Immunity , Adolescent , Child , Child, Preschool , DNA Mutational Analysis , DNA-Binding Proteins/genetics , Female , Gastrointestinal Diseases/genetics , HLA-DR Antigens/metabolism , Humans , Immunologic Deficiency Syndromes/genetics , Infant , Inflammation/genetics , Male , Mutation/genetics , Pedigree , Transcription Factors/genetics
13.
Klin Padiatr ; 230(5): 245-250, 2018 Sep.
Article in English | MEDLINE | ID: mdl-30153690

ABSTRACT

BACKGROUND: Acute viral bronchiolitis is a frequent disease in infancy. There is little knowledge on medical care of severely affected infants in different European countries. PATIENTS: Infants (n=146) with bronchiolitis requiring respiratory support in winter season 2015/2016 treated in either one of two regions in Central Europe: South of greater Paris region in France (group 1) and Ruhr area in Germany (group 2). METHODS: Retrospective chart review. Primary outcome parameter was duration of respiratory support. RESULTS: Infants in group 1 (n=96) were younger, suffered less frequently from neurologic disorders and had lower respiratory rates than in group 2 (n=50). CO2 levels and dyspnea score were similar. Ninety percent of infants in group 1 were treated by nasal Continuous Airway Pressure CPAP, while 80% of infants in group 2 were treated by High Flow Nasal Cannula HFNC. Duration of respiratory support was significantly shorter in group 1. Infants in group 2 received more frequently infusion therapy, more antibiotics and more inhalation therapy. DISCUSSION: Our results show better outcome for infants with viral bronchiolitis treated in France. Striking differences were the practice of respiratory support (nasal CPAP vs. HFNC) and the prescription of supportive treatments. CONCLUSION: Treatment approaches in severe acute viral bronchiolitis differ widely between a French and a German urban region.


Subject(s)
Bronchiolitis, Viral/therapy , Cannula , Continuous Positive Airway Pressure/statistics & numerical data , Oxygen Inhalation Therapy/methods , Oxygen Inhalation Therapy/statistics & numerical data , Practice Patterns, Physicians'/statistics & numerical data , Female , France , Germany , Humans , Infant , Male , Oxygen/blood , Retrospective Studies , Severity of Illness Index , Treatment Outcome , Urban Population
14.
Nature ; 551(7680): 327-332, 2017 11 16.
Article in English | MEDLINE | ID: mdl-29144448

ABSTRACT

Junctional epidermolysis bullosa (JEB) is a severe and often lethal genetic disease caused by mutations in genes encoding the basement membrane component laminin-332. Surviving patients with JEB develop chronic wounds to the skin and mucosa, which impair their quality of life and lead to skin cancer. Here we show that autologous transgenic keratinocyte cultures regenerated an entire, fully functional epidermis on a seven-year-old child suffering from a devastating, life-threatening form of JEB. The proviral integration pattern was maintained in vivo and epidermal renewal did not cause any clonal selection. Clonal tracing showed that the human epidermis is sustained not by equipotent progenitors, but by a limited number of long-lived stem cells, detected as holoclones, that can extensively self-renew in vitro and in vivo and produce progenitors that replenish terminally differentiated keratinocytes. This study provides a blueprint that can be applied to other stem cell-mediated combined ex vivo cell and gene therapies.


Subject(s)
Epidermal Cells , Epidermolysis Bullosa, Junctional/therapy , Regeneration , Stem Cells/cytology , Stem Cells/metabolism , Transgenes/genetics , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , Cell Differentiation , Cell Lineage , Cell Self Renewal , Cell Tracking , Child , Clone Cells/cytology , Clone Cells/metabolism , Dermis/cytology , Dermis/pathology , Epidermis/pathology , Epidermolysis Bullosa, Junctional/genetics , Epidermolysis Bullosa, Junctional/metabolism , Epidermolysis Bullosa, Junctional/pathology , Humans , Keratinocytes/cytology , Keratinocytes/metabolism , Keratinocytes/transplantation , Male , Proviruses/genetics , Kalinin
15.
Neuropediatrics ; 45(6): 346-53, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25111564

ABSTRACT

Leigh syndrome (MIM 25600), also known as infantile subacute necrotizing encephalomyelopathy, is a neurodegenerative disorder with characteristic bilateral symmetric lesions in basal ganglia and subcortical brain regions. It is commonly associated with systemic cytochrome c oxidase (COX) deficiency and mutations in the SURF1 gene (MIM 185620), encoding a putative assembly or maintenance factor of COX. The clinical course is dominated by neurodevelopmental regression, brain stem, and basal ganglia involvement (e.g., dystonia, apnea) with death often occurring before the age of 10 years. Herein, we present three sisters carrying a previously reported homozygous SURF1 mutation (c.868_869insT) that is predicted to result in a truncated protein with loss of function. Our patients show heterogeneous clinical findings with different distribution patterns of metabolic lesions in brain magnetic resonance imaging (MRI) as well as a Chiari malformation with hydrocephalus in one patient. However, all three siblings show an unusual long survival (12 years and>16 years). COX activity was not detectable in one patient and strongly reduced in the other two. We discuss these findings with respect to a review of the literature. A total of 15 additional patients with survival>14 years have been reported so far. Overall, no clear genotype-phenotype correlations are detectable among these patients.


Subject(s)
Leigh Disease/genetics , Leigh Disease/mortality , Leigh Disease/pathology , Brain/pathology , Child , Female , Humans , Membrane Proteins/genetics , Mitochondrial Proteins/genetics , Mutation , Pedigree , Siblings
16.
Exp Dermatol ; 18(1): 78-87, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19054060

ABSTRACT

Despite as yet limited clinical effectiveness, dendritic cell (DC)-based immunotherapy remains a promising approach for the treatment of cancer, but requires further improvement in its immunostimulatory effectiveness. Potent anti-tumor immunity often depends on the induction of type 1 (T(H)1) immune responses. Therefore, we combined different DC maturation stimuli that are known to induce T(H)1 immunity [anti-CD40, interleukin (IL)-12, IL-18], with the aim to trigger a T(H)1 driven anti-tumor CTL response. When compared with untreated DC or DC treated with anti-CD40 alone, DC matured with anti-CD40 plus IL-12 and IL-18 expressed significantly more IFN-gamma and IL-12, induced enhanced CD8(+) T-cell proliferation, prolonged synaptic interaction with T cells and increased CD8(+) T-cell-mediated cytotoxicity. To analyse if these DC are able to induce efficient anti-tumor immunity, mice carrying a B16-OVA tumor were treated with tumor antigen (TA)-loaded DC that had been exposed to anti-CD40 or to anti-CD40 plus IL-12 and IL-18. Our data show that anti-CD40 plus IL-12 and IL-18 matured DC are superior to controls in retarding tumor growth. These data indicate that maturation of DC with anti-CD40 plus IL-12 and IL-18 potently stimulates the generation of an anti-tumor immune response and may lead to improved immunotherapeutic capacity of DC vaccination.


Subject(s)
Antineoplastic Agents/pharmacology , CD40 Antigens/metabolism , Dendritic Cells/metabolism , Immunotherapy/methods , Interleukin-12/metabolism , Interleukin-18/metabolism , Animals , Antigens, Neoplasm/metabolism , CD8-Positive T-Lymphocytes/metabolism , Dendritic Cells/cytology , Immune System , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Models, Biological , Th1 Cells/metabolism
17.
Blood ; 109(2): 661-9, 2007 Jan 15.
Article in English | MEDLINE | ID: mdl-17003381

ABSTRACT

The beta2 integrins are important for transendothelial migration of leukocytes as well as for T-cell activation during antigen presentation. Despite abundant expression of beta2 integrins on antigen-presenting cells (APCs), their functional relevance for antigen presentation is completely unclear. We show here that dendritic cells (DCs) from CD18-deficient mice, which lack all functional beta2 integrins, have no defect in antigen presentation. Moreover, DCs from normal mice express inactive beta2 integrins that do not become activated on contact with T cells, at least in vitro. Pharmacologic activation of beta2 integrins on DCs results in a significant reduction of their T cell-activating capacity. This effect is mediated by Mac-1 (CD11b/CD18) on DCs because it could be reversed via blocking antibodies against CD18 and CD11b. Furthermore, the antigen-presenting capacity of macrophages, which express constitutively active beta2 integrins, is significantly enhanced on Mac-1 blockade. We therefore conclude that active CD11b/CD18 (Mac-1) on APCs directly inhibits T-cell activation.


Subject(s)
CD11b Antigen/physiology , CD18 Antigens/physiology , Dendritic Cells/immunology , Lymphocyte Activation/immunology , Macrophage-1 Antigen/physiology , T-Lymphocytes/immunology , Animals , Antigen Presentation/immunology , CD18 Antigens/genetics , CD18 Antigens/metabolism , Cells, Cultured , Immunophenotyping , Macrophages/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout
18.
Eur J Immunol ; 36(12): 3105-17, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17111349

ABSTRACT

The adaptive immune response is initiated when naive T cells interact with dendritic cells (DC). However, the physicodynamics as well as the molecules that constitute the contact plane (immunological synapse) between DC and T cells are not well understood. We show here that for the formation of stable conjugates, T cells need to be preactivated by DC in a CD80/86- and antigen dose-dependent manner. When activated, T cells induce cytoskeletal reorganization within DC via CD40-CD40L signaling. Polarization of the actin and fascin cytoskeleton in DC is associated with sustained DC-T cell contacts, strong T cell proliferation and a Th1 response. Organized contact planes with clearly separated patches containing TCR or CD11a are also formed. Thus, DC-T cell interactions take place in a sequential, interdependent fashion: first, DC "license" naive T cells to engage DC in an antigen dose- and CD80/86-dependent fashion. Then, these preactivated T cells induce cytoskeletal reorientation in DC, resulting in sustained DC-T cell contacts and subsequent T cell activation. These results demonstrate that T cells control the mode of interaction based on information gathered from DC.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cell Communication/immunology , Dendritic Cells/immunology , Lymphocyte Activation/immunology , Animals , B7-1 Antigen/physiology , B7-2 Antigen/genetics , CD4-Positive T-Lymphocytes/metabolism , Cell Differentiation/immunology , Cells, Cultured , Dendritic Cells/metabolism , Humans , Jurkat Cells , Mice , Mice, Inbred BALB C , Mice, Knockout , Mice, Transgenic , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...