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1.
Nutrients ; 16(6)2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38542765

RESUMO

(1) Background: Vitamin D levels in patients remain inadequately understood, with research yielding inconsistent findings. Breast cancer patients, particularly due to oncological therapies, face an increased risk of osteopenia, which can be exacerbated by a vitamin D deficiency. (2) Methods: The prospective observational "BEGYN-1" study assessed serum 25(OH)D levels at baseline and quarterly thereafter. Clinical, pathological, nutritional, vitamin supplementation, and lifestyle data were recorded. (3) Results: Before treatment, 68.5% of patients were vitamin D deficient (<30 ng/mL), with 4.6% experiencing severe deficiency (<10 ng/mL). The median baseline 25(OH)D levels were 24 ng/mL (range: 4.8 to 64.7 ng/mL). Throughout the study, the median vitamin D levels increased to 48 ng/mL (range: 22.0 to 76.7 ng/mL). Before diagnosis, 16.7% received vitamin D substitution, and 97.8% received vitamin D substitution throughout the year with a median weekly dose of 20,000 IU. It took at least three quarterly assessments for 95% of patients to reach the normal range. A multiple GEE analysis identified associations between 25(OH)D levels and supplementation, season, age, VLDL, magnesium levels, and endocrine therapy. (4) Conclusions: Physicians should monitor 25(OH)D levels before, during, and after oncological therapy to prevent vitamin D deficiency and to adjust substitution individually. While variables such as seasons, age, VLDL, magnesium, diet, and oncological interventions affect 25(OH)D levels, supplementation has the greatest impact.


Assuntos
Neoplasias da Mama , Deficiência de Vitamina D , Humanos , Feminino , Vitamina D , Neoplasias da Mama/tratamento farmacológico , Magnésio/uso terapêutico , Vitaminas , Suplementos Nutricionais
2.
BMC Med Educ ; 24(1): 134, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347593

RESUMO

BACKGROUND: It is a crucial task for physicians to deliver life threatening information to patients (breaking bad news; BBN). Many aspects influence these conversations on both sides, patients, and doctors. BBN affects the patient-physician relationship, patients' outcome, and physicians' health. Many physicians are still untrained for this multi-facetted task and feel unprepared and overburdened when facing situations of BBN. Therefore, any faculties should aim to integrate communication skills into their medical curricula as early as possible. The SPIKES protocol is an effective framework to deliver BBN. Aim of this study is to evaluate the feasibility and obstacles of a BBN seminar and its acceptance and learning curve among undergraduate medical students. METHODS: 158 2nd year undergraduate medical students attended a compulsory BBN seminar. The task was to deliver a cancer diagnosis to the patient within a patient - physician role-play in a gyneco-oncological setting before and after a presentation of the SPIKES protocol by the lecturer. The students evaluated important communication skills during these role-plays respectively. Self-assessment questionnaires were obtained at the beginning and end of the seminar. RESULTS: Most students indicated that their confidence in BBN improved after the seminar (p < 0.001). They like the topic BBN to be part of lectures (76%) and electives (90%). Communication skills improved. Lecturer and seminar were positively evaluated (4.57/5). CONCLUSION: The seminar significantly increased confidence and self-awareness in delivering life-threatening news to patients among undergraduate medical students. Important learning aspects of BBN and communication skills could be delivered successfully to the participants within a short time at low costs. The integration of communication skills should be implemented longitudinally into medical curricula starting before clinical education to increase the awareness of the importance of communication skills, to decrease anxiety, stress, and workload for future doctors and- most importantly- to the benefit of our patients.


Assuntos
Médicos , Estudantes de Medicina , Humanos , Estudos de Viabilidade , Revelação da Verdade , Relações Médico-Paciente , Comunicação
3.
Oncologist ; 28(12): e1152-e1159, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37555463

RESUMO

BACKGROUND: Eribulin, a halichondrin-class microtubule dynamics inhibitor, is a preferred treatment option for patients with advanced breast cancer who have been pretreated with an anthracycline and a taxane. Peripheral neuropathy (PN) is a common side effect of chemotherapies for breast cancer and other tumors. The Incidence and Resolution of Eribulin-Induced Peripheral Neuropathy (IRENE) noninterventional postauthorization safety study assessed the incidence and severity of PN in patients with breast cancer treated with eribulin. PATIENTS AND METHODS: IRENE is an ongoing observational, single-arm, prospective, multicenter, cohort study. Adult patients (≥18 years of age) with locally advanced or metastatic breast cancer and disease progression after 1-2 prior chemotherapeutic regimen(s) for advanced disease were treated with eribulin. Patients with eribulin-induced PN (new-onset PN or worsening of preexisting PN) were monitored until death or resolution of PN. Primary endpoints included the incidence, severity, and time to resolution of eribulin-induced PN. Secondary endpoints included time to disease progression and safety. RESULTS: In this interim analysis (data cutoff date: July 1, 2019), 67 (32.4%) patients experienced any grade eribulin-induced PN, and 12 (5.8%) patients experienced grade ≥3 eribulin-induced PN. Median time to resolution of eribulin-induced PN was not reached. Median time to disease progression was 4.6 months (95% CI, 4.0-6.5). Treatment-emergent adverse events (TEAEs) occurred in 195 (93.8%) patients and serious TEAEs occurred in 107 (51.4%) patients. CONCLUSION: The rates of any grade and grade ≥3 eribulin-induced PN observed in this real-world study were consistent with those observed in phase III randomized clinical trials. No new safety findings were observed.


Assuntos
Neoplasias da Mama , Doenças do Sistema Nervoso Periférico , Adulto , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Estudos de Coortes , Progressão da Doença , Furanos/efeitos adversos , Incidência , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/epidemiologia , Estudos Prospectivos , Resultado do Tratamento , Moduladores de Tubulina/efeitos adversos
4.
Front Oncol ; 13: 1198157, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37637039

RESUMO

Background: Breast cancer is the most frequent cancer in women. Reduced physical activity and overweight are associated with poor prognosis. Breast cancer patients have a high risk to gain weight, lose muscle mass and reduce physical activity during therapy. Concepts are urgently needed to motivate patients to engage in physical activity. Methods: 110 non-metastatic breast cancer patients were included in the prospective observational BEGYN-1 study. Physiological parameters and body composition were measured before the start of therapy and then quarterly for one year. Patients used a fitness tracker and documented their physical activity in a diary throughout the study. Results: Although the patients were not offered any guided exercise, and despite the restrictions during the COVID-19 pandemic, they increased their physical activity (metabolic equivalent of task (MET) -minutes): p<0.001), physical fitness (decreasing resting heart rate: p=0.001) and did not gain weight (median - 0.4kg) over the course of the study. Conclusion: Improved awareness of physical activity is associated with an increase in physical activity, fitness, and a stable weight during the first year of therapy in breast cancer patients. Counselling at diagnosis should motivate patients to engage in physical activity, wear a fitness tracker and document activities.

5.
Nutrients ; 15(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36986179

RESUMO

(1) Background: Vitamin D plays an important role in many types of cancer. It was the aim of this study to analyze serum 25-hydroxyvitamin D (25(OH)D) levels in newly diagnosed breast cancer patients, and the association with prognostic and lifestyle factors. (2) Methods: 110 non-metastatic breast cancer patients were included in the prospective observational "BEGYN" study at Saarland University Medical Center between September 2019 and January 2021. At the initiation visit, serum 25(OH)D levels were measured. Clinicopathological data on prognosis, nutrition, and lifestyle were extracted from data files and obtained using a questionnaire. (3) Results: Median serum 25(OH)D in breast cancer patients was 24 ng/mL (range 5-65 ng/mL), with 64.8% of patients being vitamin D deficient. 25(OH)D was higher among patients that reported the use of vitamin D supplements (43 ng/mL versus 22 ng/mL; p < 0.001), and in summer compared to other seasons (p = 0.03). Patients with moderate vitamin D deficiency were less likely to have triple negative breast cancer (p = 0.047). (4) Conclusions: Routinely measured vitamin D deficiency is common in breast cancer patients and needs to be detected and treated. However, our results do not support the hypothesis that vitamin D deficiency may be a main prognostic factor for breast cancer.


Assuntos
Neoplasias da Mama , Deficiência de Vitamina D , Humanos , Feminino , Neoplasias da Mama/complicações , Neoplasias da Mama/epidemiologia , Projetos Piloto , Prevalência , Vitamina D
6.
Front Oncol ; 11: 762709, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737966

RESUMO

BACKGROUND: Moderate physical activity is associated with an improved prognosis and psychosocial outcome in breast cancer patients. Although exercise and physical activity are associated with multiple physiological and psychological effects, many of the underlying mechanisms remain obscure. The BEGYN study (Influence of physical activity in breast cancer patients on physiological and psychological parameters and on biomarkers) aims at identifying potential associations between the extent of physical activity, fitness, body composition, immunological biomarkers, psycho-emotional parameters, and the course of treatment during the first year after diagnosis of breast cancer. METHODS: The prospective observational BEGYN study will include 110 non-metastatic breast cancer patients. The patients will be assessed during a base line visit prior to the initiation of the antineoplastic therapy and after 3, 6, 9 and 12 months. The physical activity will be measured using a fitness tracker and a self-assessment diary during the entire study. Each visit will include the assessment of (i) cardiorespiratory fitness measured by spiroergometry, (ii) body composition, (iii) psycho-emotional parameters (quality of life, mental health, fatigue, depression, distress, anxiety, well-being), and (iv) extensive blood tests including routine laboratory, vitamin D, selenium and immunologically relevant biomarkers (e.g., leukocyte subpopulations and cytokine profiles). DISCUSSION: Whereas most studies investigating the influence of physical activity in breast cancer patients focus on specific activities for three months or less, the BEGYN study will quantify the daily physical activity and cardiorespiratory fitness of breast cancer patients based on objective measurements in the context of the oncological therapy for 12 months after diagnosis. The study will reveal potential associations between exercise, immune status and physical as well as psycho-emotional outcome and the clinical course of the disease. Moreover, complementary therapies such as Vit D and Selenium supplementation and parameters investigating the motivation of the patients are part of the study. Due to this holistic approach, the BEGYN study will guide towards confirmatory studies on the role of physical activity in breast cancer patients to develop individualized counselling regarding the recommended type and extent of exercise. TRIAL REGISTRATION: This study has been registered at the German Clinical Trials Register DRKS00024829.

7.
J Exp Med ; 210(5): 875-90, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23589567

RESUMO

Selection and physiological production of protective natural antibodies (NAbs) have been associated with exposure to endogenous antigens. The extent to which this association depends on germline NAb sequence is uncertain. Here we show that alterations in germline D(H) sequence can sever the association between the production of self-reactive NAbs and NAbs that afford protection against a pathogen. In unmanipulated hosts, the availability of the evolutionarily conserved DFL16.1 gene segment sequence profoundly affected the serum levels of NAbs against bacterial phosphorylcholine but not oxidized low-density lipoprotein. Mice with partially altered DFL16.1 sequence could use N nucleotides to recreate the amino acid sequence associated with the classical protective T15 idiotype­positive NAbs, whereas those without DFL16.1 could not. DFL16.1 gene-deficient mice proved more susceptible to challenge with live Streptococcus pneumoniae. Our findings indicate that although production of self-reactive NAbs can be independent of germline D(H) sequence, their capacity to provide protection against pathogens cannot. The potential relevance of these findings for the rational design of vaccines is discussed.


Assuntos
Anticorpos/imunologia , Sequência Conservada/genética , Cadeias Pesadas de Imunoglobulinas/genética , Lipoproteínas LDL/imunologia , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/prevenção & controle , Streptococcus pneumoniae/imunologia , Sequência de Aminoácidos , Animais , Anticorpos/sangue , Anticorpos/química , Formação de Anticorpos/imunologia , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/genética , Reações Cruzadas/imunologia , Evolução Molecular , Mutação da Fase de Leitura/genética , Loci Gênicos/genética , Células Germinativas/imunologia , Imunização , Cadeias Pesadas de Imunoglobulinas/química , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Fosforilcolina/imunologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
8.
J Immunol ; 189(11): 5449-56, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23105134

RESUMO

After birth, contact to environmental Ags induces the production of IgA, which represents a first line of defense for the neonate. We sought to characterize the maturation of the repertoire of IgA H chain transcripts in circulating blood B cells during human ontogeny. We found that IgA H chain transcripts were present in cord blood as early as 27 wk of gestation and that the restrictions of the primary Ab repertoire (IgM) persisted in the IgA repertoire. Thus, B cells harboring more "mature" V(H) regions were not preferred for class switch to IgA. Preterm and term neonates expressed a unique IgA repertoire, which was characterized by short CDR-H3 regions, preference of the J(H) proximal D(H)7-27 gene segment, and very few somatic mutations. During the first postnatal months, these restrictions were slowly released. Preterm birth did not measurably accelerate the maturation of the IgA repertoire. At a postconceptional age of 60 wk, somatic mutation frequency of IgA H chain transcripts reached 25% of the adult values but still showed little evidence of Ag-driven selection. These results indicate that similar to IgG, the IgA repertoire expands in a controlled manner after birth. Thus, the IgA repertoire of the newborn has distinctive characteristics that differ from the adult IgA repertoire. These observations might explain the lower affinity and specificity of neonatal IgA Abs, which could contribute to a higher susceptibility to infections and altered responses to vaccinations, but might also prevent the development of autoimmune and allergic diseases.


Assuntos
Antígenos/imunologia , Linfócitos B/imunologia , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Imunoglobulina A/genética , Cadeias Pesadas de Imunoglobulinas/genética , RNA Mensageiro/imunologia , Adulto , Afinidade de Anticorpos , Diversidade de Anticorpos , Especificidade de Anticorpos , Linfócitos B/metabolismo , Sequência de Bases , Sangue Fetal , Idade Gestacional , Humanos , Imunidade Inata , Switching de Imunoglobulina , Imunoglobulina M/genética , Região Variável de Imunoglobulina/genética , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Dados de Sequência Molecular , RNA Mensageiro/biossíntese
9.
Psychother Psychosom Med Psychol ; 62(3-4): 129-35, 2012.
Artigo em Alemão | MEDLINE | ID: mdl-22473429

RESUMO

Health-related quality of life (QoL) in breast cancer patients strongly depends on emotional well-being. QoL (EORTC-QLQ-C30), psychological distress (HADS), and patient's request for psycho-oncological care were assessed in 103 breast cancer patients during initial hospitalization. Clinical diagnoses according to ICD-10-F were made by clinical interview. As expected, both positive HADS screens (>13) and clinical diagnoses of mental disorders were inversely related to QoL. However, in multivariate analysis of variance only positive HADS scores but not clinical diagnoses of mental disorders significantly predicted QoL. The performance of psychological screening instruments should therefore not only be judged by their ability to detect clinical diagnoses but also by their relevance for reflecting patients' QoL.


Assuntos
Neoplasias da Mama/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Qualidade de Vida , Estresse Psicológico/psicologia , Adulto , Idoso de 80 Anos ou mais , Neoplasias da Mama/complicações , Cognição/fisiologia , Interpretação Estatística de Dados , Emoções/fisiologia , Feminino , Hospitalização , Humanos , Classificação Internacional de Doenças , Transtornos Mentais/complicações , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Análise Multivariada , Testes Neuropsicológicos , Estresse Psicológico/etiologia
10.
Breast Care (Basel) ; 6(3): 221-226, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21779228

RESUMO

BACKGROUND: Breast care nurses (BCNs) are specialized caregivers in certified breast cancer center teams. The impact of a BCN's work remains unknown. PATIENTS AND METHODS: The role of BCN care was evaluated in a post-discharge mail survey of 360 patients. RESULTS: A total of 207 (87%) of 237 (66%) returned questionnaires were analyzed; 171 (83%) patients had BCN contact, 36 (17%) did not. The mean global quality of life scores (EORTC-QLQ-C30) were 66.3 for women with contact to a BCN versus 62.5 for women without such contact (p < 0.05). Women with a BCN contact had better results than women without (p < 0.001) for the following parameters: receipt of information material (84 vs. 64%), information about hospital procedures (93 vs. 72%) and treatment plan (91 vs. 63%), and knowledge of own tumor hormone receptor status (83 vs. 53%). Medication adherence correlated with the knowledge about the tumor hormone receptor status and was significantly higher in women having contact with a BCN (79 vs. 56%). The high recommendation rate (81%) reflects the high level of satisfaction with BCNs. A qualitative analysis of comments and suggestions identified aspects to improve BCN services. CONCLUSIONS: BCN improve satisfaction and treatment adherence in breast cancer patients.

11.
J Immunol ; 181(12): 8416-24, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19050259

RESUMO

In jawed vertebrates most expressed Ig H chains use only one of six possible D(H) reading frames. Reading frame (RF)1, the preferred reading frame, tends to encode tyrosine and glycine, whereas the other five RFs tend to be enriched for either hydrophobic or charged amino acids. Mechanisms proposed to favor use of RF1 include a preference for deletion over inversion that discourages use of inverted RF1, RF2, and RF3; sequence homology between the 5' terminus of the J(H) and the 3' terminus of the D(H) that promotes rearrangement into RF1; an ATG start site upstream of RF2 that permits production of a truncated Dmicro protein; stop codons in RF3; and, following surface expression of IgM, somatic, presumably Ag receptor-based selection favoring B cells expressing Igs with tyrosine- and glycine-enriched CDR-H3s. By creating an IgH allele limited to the use of a single, frameshifted DFL16.1 D(H) gene segment, we tested the relative contribution of these mechanisms in determining reading frame preference. Dmicro-mediated suppression via an allelic exclusion-like mechanism dominated over somatic selection in determining the composition of the CDR-H3 repertoire. Evidence of somatic selection for RF1-encoded tyrosine in CDR-H3 was observed, but only among the minority of recirculating, mature B cells that use D(H) in RF1. These observations underscore the extent to which the sequence of the D(H) acts to delimit the diversity of the Ab repertoire.


Assuntos
Diversidade de Anticorpos/genética , Subpopulações de Linfócitos B/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Mutação da Fase de Leitura , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Fases de Leitura/genética , Fases de Leitura/imunologia , Animais , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/metabolismo , Linhagem Celular , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Dados de Sequência Molecular
12.
J Virol ; 81(17): 9331-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17567700

RESUMO

Heterosubtypic immunity (HSI) is defined as cross-protection to infection with an influenza A virus serotype other than the one used for primary infection. Although HSI has been thought to be mediated by serotype cross-reactive cytotoxic T lymphocytes (CTL) that recognize conserved epitopes of structural proteins, recent studies suggest that antibodies (Abs) may make a significant contribution. In this study, we provide further evidence for the role of Abs in HSI using transgenic mice lacking terminal deoxyribonucleotidyltransferase (TdT), which adds N nucleotides to V-D and D-J junctions of the complementary determining region 3 (CDR3) (TdT(-/-)) and mice with altered Ab repertoires due to replacement of the complete locus of heavy chain diversity segments (D(H)) with an altered D(H) segment (namely, Delta D-iD). Both types of mice failed to generate complete HSI, although they were able to mount protective immunity to a homologous challenge. Lower levels of virus-specific antibodies along with more severely impaired HSI were observed in TdT(-/-) mice compared to those in Delta D-iD mice, while CTL activity remained unchanged in both types of mice. These findings indicate that a properly diversified antibody repertoire is required for HSI and that N addition by TdT is a more effective mechanism in the induction of a properly diversified antibody repertoire and, therefore, complete HSI. The results suggest that the diversity of the antibody repertoire as determined by the composition of the D region of HCDR3 and by N addition are among the mechanisms selected for in evolution to create a favorable environment to resolve infections with mutated viruses.


Assuntos
Anticorpos Antivirais/imunologia , Reações Cruzadas , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Peso Corporal , DNA Nucleotidilexotransferase/deficiência , Modelos Animais de Doenças , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Deleção de Sequência , Análise de Sobrevida , Subpopulações de Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia
13.
J Immunol ; 178(2): 1180-8, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17202383

RESUMO

During the perinatal period the development of the IgH chain CDR3 (CDR-H3) repertoire of IgM transcripts is maturity-dependent and not influenced by premature exposure to Ag. To study whether maturity-dependent restrictions also predominate in the perinatal IgG repertoire we compared 1000 IgG transcripts from cord blood and venous blood of extremely preterm neonates (24-28 wk of gestation) and of term neonates from birth until early infancy with those of adults. We found the following. First, premature contact with the extrauterine environment induced the premature development of an IgG repertoire. However after preterm birth the diversification of the IgG repertoire was slower than that after term birth. Second, the IgG repertoire of preterm neonates retained immature characteristics such as short CDR-H3 regions and overrepresentation of D(H)7-27. Third, despite premature exposure to the extrauterine environment, somatic mutation frequency in IgG transcripts of preterm infants remained low until they reached a postconceptional age corresponding to the end of term gestation. Thereafter, somatic mutations accumulated with age at similar rates in preterm and term neonates and reached 30% of the adult level after 6 mo. In conclusion, class switch was inducible already at the beginning of the third trimester of gestation, but the developing IgG repertoire was characterized by similar restrictions as those of the developing IgM repertoire. Those B cells expressing more "mature" H chain sequences were not preferentially selected into the IgG repertoire. Therefore, the postnatal IgG repertoire of preterm infants until the expected date of delivery differs from the postnatal repertoire of term neonates.


Assuntos
Diversidade de Anticorpos/imunologia , Idade Gestacional , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/imunologia , Recém-Nascido Prematuro/imunologia , Nascimento a Termo , Diversidade de Anticorpos/genética , Feminino , Humanos , Recém-Nascido , Mutação/genética , Gravidez , Fatores de Tempo , Transcrição Gênica/genética , Útero/imunologia
14.
J Exp Med ; 203(6): 1567-78, 2006 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-16754718

RESUMO

Tyrosine and glycine constitute 40% of complementarity determining region 3 of the immunoglobulin heavy chain (CDR-H3), the center of the classic antigen-binding site. To assess the role of D(H) RF1-encoded tyrosine and glycine in regulating CDR-H3 content and potentially influencing B cell function, we created mice limited to a single D(H) encoding asparagine, histidine, and arginines in RF1. Tyrosine and glycine content in CDR-H3 was halved. Bone marrow and spleen mature B cell and peritoneal cavity B-1 cell numbers were also halved, whereas marginal zone B cell numbers increased. Serum immunoglobulin G subclass levels and antibody titers to T-dependent and T-independent antigens all declined. Thus, violation of the conserved preference for tyrosine and glycine in D(H) RF1 alters CDR-H3 content and impairs B cell development and antibody production.


Assuntos
Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Sequência de Aminoácidos , Aminoácidos/imunologia , Animais , Cadeias Pesadas de Imunoglobulinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular
15.
Mol Immunol ; 42(7): 789-98, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15829267

RESUMO

Anti-dsDNA antibodies tend to be enriched for heavy chain complementarity determining region 3 (CDR-H3) intervals of above average length that contain an increased frequency of charged amino acids. It is unclear whether these types of CDR-H3s are more common in the primary B-cell repertoire of auto-immune prone strains or whether their increased prevalence in affected individuals reflects positive selection and expansion of atypical CDR-H3s in the pathogenic response to self-antigen. Here, we present evidence that when compared to C3H, a MRL/MpJ(2+) parental strain, CDR-H3 intervals from pre-B cells of adult lupus-prone MRL/MpJ(2+) mice are longer on average and are enriched for charged amino acids. The predicted prevalence of deformed loops per Shirai H3 criteria is also higher. In contrast, the frequency of charge, the distribution of length, and the pattern of predicted deformed loop structures did not differ in sequences obtained from neonates of the same two strains. These observations suggest that the mechanisms that serve to shape the initial CDR-H3 repertoire in adults, but not neonates, are being regulated differently in C3H versus MRL/MpJ(2+). Dysregulation of the adult pre-B CDR-H3 antibody repertoire could be a contributing factor for the development of florid auto-immune disease in MRL/MpJ(2+) mice.


Assuntos
Linfócitos B/imunologia , Regiões Determinantes de Complementaridade/genética , Regulação da Expressão Gênica no Desenvolvimento , Cadeias Pesadas de Imunoglobulinas/genética , Lúpus Vulgar/genética , Lúpus Vulgar/imunologia , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Autoimunidade , Sequência de Bases , Células da Medula Óssea/imunologia , Regiões Determinantes de Complementaridade/biossíntese , Regiões Determinantes de Complementaridade/química , DNA/análise , DNA/imunologia , Cadeias Pesadas de Imunoglobulinas/biossíntese , Cadeias Pesadas de Imunoglobulinas/química , Fígado/imunologia , Lúpus Vulgar/sangue , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos
16.
J Mol Biol ; 334(4): 733-49, 2003 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-14636599

RESUMO

Immunoglobulin junctional diversity is concentrated in the third complementarity-determining region of the heavy chain (CDR-H3), which often plays a dominant role in antigen binding. The range of CDR-H3 lengths in mouse is shorter than in human, and thus the murine repertoire could be presumed to be a subset of the human one. To test this presumption, we analyzed 4751 human and 2170 murine unique, functional, published CDR-H3 intervals. Although tyrosine, glycine, and serine were found to predominate in both species, the human sequences contained fewer tyrosine residues, more proline residues, and more hydrophobic residues (p<0.001, respectively). While changes in amino acid utilization as a function of CDR-H3 length followed similar trends in both species, murine and human CDR-H3 intervals of identical length were found to differ from each other. These differences reflect both divergence of germline diversity and joining gene sequence and somatic selection. Together, these factors promote the production of a rather uniform repertoire in mice of tyrosine-enriched CDR-H3 loops with stabilized hydrogen bond-ladders versus a much more diverse repertoire in human that contains CDR-H3 loops sculpted by the presence of intra-chain disulfide bonds due to germline-encoded cysteine residues as well as the enhanced presence of somatically generated proline residues that preclude hydrogen bond ladder formation. Thus, despite the presumed need to recognize a similar range of antigen epitopes, the murine CDR-H3 repertoire is clearly distinct from its human counterpart in its amino acid composition and its predicted range of structures. These findings represent a benchmark to which CDR-H3 repertoires can be compared to better characterize and understand the shaping of the CDR-H3 repertoire over evolution and during immune responses. This information may also be useful for the design of species-specific CDR-H3 sequences in synthetic antibody libraries.


Assuntos
Regiões Determinantes de Complementaridade/química , Cadeias Pesadas de Imunoglobulinas/química , Conformação Proteica , Sequência de Aminoácidos , Animais , Regiões Determinantes de Complementaridade/genética , Regiões Determinantes de Complementaridade/metabolismo , Cristalografia por Raios X , Cisteína/metabolismo , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/metabolismo , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
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