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1.
Vaccine ; 33(31): 3717-25, 2015 Jul 17.
Article in English | MEDLINE | ID: mdl-26057135

ABSTRACT

Prior study children from a DTaP efficacy trial were recruited at ages 5 and 15 years to randomized booster trials addressing immunogenicity and reactogenicity; 475 preschool children received mixed or separate injections of a reduced antigen vaccine (Tdap5, Sanofi Pasteur MSD) and an inactivated polio vaccine, and 230 adolescents received the same or another booster vaccine (Tdap1, SSI, Denmark). Pre-vaccination antibody concentrations against pertussis antigens were significantly higher at 15 than 5 years of age, probably due to natural boosting between the studies. Tdap5 induced comparable anti-PT concentrations at both ages, but antibody responses were significantly higher to filamentous haemagglutinin, pertactin and fimbriae 2/3 in adolescents. As expected, a higher amount of PT (Tdap1, 20µg) induced a stronger anti-PT response than a lower amount (Tdap5, 2.5µg). The frequency of adverse events was low and there were no serious adverse reactions. All local reactions had an early onset and a short duration. A large swelling or redness of more than half of the upper arm circumference was reported in 8/475 5-year-olds and in 6/230 15-year-olds. Children vaccinated with Tdap5 reported more moderate pain in adolescence than at preschool age, whereas itching was only reported in preschool children. Sweden introduced DTaP vaccines in 1996 after a 17-year hiatus with no general pertussis vaccination and pertussis was still endemic at the time of the studies. The frequency of adverse events was nevertheless low in both preschool children and adolescents and antibody responses were adequate. These studies document immunogenicity and reactogenicity in a trial cohort consecutively vaccinated with acellular pertussis vaccines from infancy to adolescence. The adolescent study was registered at ClinicalTrials.gov on 26 March 2009 (NCT00870350).


Subject(s)
Antibodies, Bacterial/blood , Diphtheria-Tetanus-acellular Pertussis Vaccines/administration & dosage , Diphtheria-Tetanus-acellular Pertussis Vaccines/immunology , Immunization, Secondary/methods , Whooping Cough/prevention & control , Adolescent , Child, Preschool , Diphtheria-Tetanus-acellular Pertussis Vaccines/adverse effects , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Humans , Immunization, Secondary/adverse effects , Male , Sweden , Treatment Outcome
2.
Euro Surveill ; 20(6)2015 Feb 12.
Article in English | MEDLINE | ID: mdl-25695476

ABSTRACT

In Sweden, pertussis was excluded from the national vaccination programme in 1979 until acellular vaccination was introduced in a highly endemic setting in 1996. The general incidence dropped 10-fold within a decade, less in infants. Infant pertussis reached 40-45 cases per 100,000 in 2008 to 2012; few of these cases were older than five months. We present an observational 15-year study on the severity of infant pertussis based on 1,443 laboratory-confirmed cases prospectively identified from 1998 to 2012 in the national mandatory reporting system and followed up by telephone contact. Analyses were made in relation to age at onset of symptoms and vaccination history. Pertussis decreased in non-vaccinated infants (2003 to 2012, p<0.001), indicating herd immunity, both in those too young to be vaccinated and those older than three months. The hospitalisation rates also decreased (last five-year period vs the previous five-year periods, p <0.001), but 70% of all cases in under three month-old infants and 99% of cases with apnoea due to pertussis were admitted to hospital in 1998 to 2012. Median duration of hospitalisation was seven days for unvaccinated vs four days for vaccinated infants aged 3-5 months. Nine unvaccinated infants died during the study period.


Subject(s)
Hospitalization/statistics & numerical data , Pertussis Vaccine/immunology , Whooping Cough/epidemiology , Whooping Cough/prevention & control , Child , Child, Preschool , Hospitalization/trends , Humans , Immunization Programs , Incidence , Infant , Infant, Newborn , Mandatory Reporting , National Health Programs , Pertussis Vaccine/administration & dosage , Population Surveillance , Severity of Illness Index , Sweden/epidemiology , Vaccination/methods , Whooping Cough/pathology
4.
Aliment Pharmacol Ther ; 37(9): 905-14, 2013 May.
Article in English | MEDLINE | ID: mdl-23451861

ABSTRACT

BACKGROUND: Studies have shown an increased risk of ischaemic heart disease (IHD) in patients with coeliac disease (CD), despite the patients' lack of traditional IHD risk factors. AIM: To characterise IHD according to CD status. METHODS: Data on duodenal or jejunal biopsies were collected in 2006-2008 from all 28 pathology departments in Sweden and were used to define CD (equal to villous atrophy; Marsh stage 3). We used the Swedish cardiac care register SWEDEHEART to identify IHD and to obtain data on clinical status and risk factors at time of first myocardial infarction for this case-only comparison. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). CD patients were compared with general population reference individuals. RESULTS: We identified 1075 CD patients and 4142 reference individuals with subsequent IHD. CD patients with myocardial infarction had lower body mass index (P < 0.001) and cholesterol values (P < 0.001) and were less likely to be active smokers (OR = 0.74; 95% CI = 0.56-0.98) than reference individuals with myocardial infarction. CD patients had less extensive coronary artery disease at angiography (any stenosis: OR = 0.80; 95% CI = 0.66-0.97; three-vessel disease: OR = 0.73; 95% CI = 0.57-0.94); but there was no difference in the proportions of CD patients with positive biochemical markers of myocardial infarction (CD: 92.2% vs. reference individuals: 91.5%, P = 0.766). CONCLUSION: Despite evidence of an increased risk of IHD and higher cardiovascular mortality, patients with coeliac disease with IHD have a more favourable cardiac risk profile compared with IHD in reference individuals.


Subject(s)
Celiac Disease/complications , Myocardial Ischemia/etiology , Adult , Aged , Aged, 80 and over , Celiac Disease/epidemiology , Databases, Factual , Female , Humans , Logistic Models , Male , Middle Aged , Myocardial Ischemia/epidemiology , Myocardial Ischemia/physiopathology , Odds Ratio , Risk Factors , Sweden/epidemiology
6.
Acta Psychiatr Scand ; 113(2): 102-11, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16423161

ABSTRACT

OBJECTIVE: To examine neuropsychological performance as a possible predictor of course and outcome in first-episode psychotic (FEP) patients. METHOD: A group of consecutive FEP patients (n = 120) tested with Wechsler Adult Intelligence Scales-Revised (WAIS-R) at baseline was compared with a healthy group (n = 30) matched for age, education and gender. Relationship between WAIS-R and both Brief Psychiatric Rating Scale and Global Assessment of Function (GAF) ratings were studied at baseline and at 1- and 3-year follow-ups. RESULTS: The performance of FEP patients was significantly lower (P < 0.001) than that of healthy comparison subjects on all WAIS-R subtests except for Information and Comprehension. The WAIS-R scores of patients with schizophrenia syndromes (DSM-IV) were lower than those of patients with non-schizophrenia syndromes on Block Design. Low WAIS-R Full-Scale IQ scores in FEP patients predicted the presence of negative symptoms at 1-year follow-up and of low GAF ratings at 3-year follow-up. CONCLUSION: Neurocognitive performance at admission appears to predict various aspects of functional outcome in FEP.


Subject(s)
Cognition Disorders/diagnosis , Psychotic Disorders/diagnosis , Schizophrenia/diagnosis , Wechsler Scales/statistics & numerical data , Adolescent , Adult , Antipsychotic Agents/administration & dosage , Brief Psychiatric Rating Scale/statistics & numerical data , Cognition Disorders/psychology , Cognition Disorders/therapy , Cohort Studies , Combined Modality Therapy , Comorbidity , Dose-Response Relationship, Drug , Female , Follow-Up Studies , Humans , Male , Middle Aged , Patient Admission , Predictive Value of Tests , Psychometrics/statistics & numerical data , Psychotic Disorders/psychology , Psychotic Disorders/therapy , Remission Induction , Schizophrenia/therapy , Sensitivity and Specificity
7.
Scand Cardiovasc J ; 39(1-2): 50-4, 2005 Apr.
Article in English | MEDLINE | ID: mdl-16097414

ABSTRACT

OBJECTIVE: We have investigated whether perceived quality of life has an impact on long-term survival after a cardiac event. DESIGN: Male (n = 316) and female (n = 97) patients were assessed by means of a self-administered quality of life questionnaire 1 year after either acute myocardial infarction (n = 296), coronary artery bypass grafting surgery (n = 99) or percutaneous coronary intervention (n = 18). Inclusion period was 1989-1991. Ten years after the last patient answered the 1-year questionnaire, mortality (status factor) up to census date was analysed using nine dimensions of quality of life as covariates (Cox regression). RESULTS: At 1-year assessment, subjective general health (RR = 3.15), perceived arrhythmia (RR = 1.72), experience of sex life (RR = 1.55), perceived breathlessness (RR = 1.50) and experience of self-esteem (RR = 1.48) were all significantly related to death within the period up to census date. CONCLUSION: The findings highlight that the patients' own experience of his or her quality of life, has a prognostic importance for long-term mortality after a cardiac event. Clinicians should be aware that a careful monitoring of perceived quality of life is an important part of good patient care.


Subject(s)
Cause of Death , Myocardial Infarction/mortality , Myocardial Infarction/therapy , Quality of Life , Adaptation, Physiological , Aged , Angioplasty, Balloon, Coronary/statistics & numerical data , Coronary Angiography , Coronary Artery Bypass/statistics & numerical data , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Myocardial Infarction/diagnostic imaging , Myocardial Ischemia/diagnostic imaging , Myocardial Ischemia/mortality , Myocardial Ischemia/therapy , Predictive Value of Tests , Prognosis , Risk Assessment , Severity of Illness Index , Sickness Impact Profile , Statistics, Nonparametric , Surveys and Questionnaires , Survival Analysis , Sweden , Time Factors , Treatment Outcome
8.
Scand J Gastroenterol ; 39(12): 1280-8, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15743007

ABSTRACT

BACKGROUND: Upper oesophagogastroduodenoscopy is considered to be the gold standard for upper gastrointestinal disease assessment, but is currently seldom used in epidemiological studies. One concern is that the procedure may bias sampling among volunteers in a general adult population. The aim of this study was to explore whether the procedure affects symptom reporting. METHODS: A random sample of 3000 adults aged 20-81 years (mean age 50.4), from two Swedish municipalities (n=21,610) was surveyed using a validated postal questionnaire (the Abdominal Symptom Questionnaire) assessing gastrointestinal symptoms. A subsample of the responders was invited, in random order, to undergo an upper endoscopy and repeated symptom reporting using the same questionnaire, as well as a serology test for Helicobacter pylori. RESULTS: The response rate to the initial questionnaire was 74.2% and the participation rate for those eligible for the upper endoscopy was 73.3% (n = 1001, mean age 54.0 years, 48.8% male). No major social or symptom sampling error was encountered from the selection process, with the exception of an excess of symptom reporters among the youngest subjects. The prevalence of reflux symptoms, dyspeptic symptoms and irritable bowel symptoms was 40%, 37.6% and 29.6%, respectively, which is relatively high, but in no way extreme. CONCLUSIONS: The upper endoscopy survey strategy was successful. The response rate was high and there was no major selection bias of clinical relevance. The cohort selected for this study appears to be representative of the general Swedish adult population.


Subject(s)
Digestive System Diseases/complications , Digestive System Diseases/diagnosis , Endoscopy, Digestive System , Health Surveys , Adult , Age Factors , Aged , Bias , Epidemiologic Studies , Feasibility Studies , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sampling Studies , Sweden
10.
Dig Dis ; 20(2): 191-8, 2002.
Article in English | MEDLINE | ID: mdl-12566622

ABSTRACT

BACKGROUND/AIMS: Symptoms are generally considered to be poor predictors of organic findings in patients with dyspepsia. We aimed at evaluating whether specific gastrointestinal symptoms, identified by self-administered questionnaires, correlate with specific endoscopic diagnoses and discriminate organic from functional dyspepsia. METHODS: Adult patients with pain or discomfort centred in the upper abdominal region were consecutively enrolled. Patients with heartburn, acid regurgitation, or defaecation and bowel habit problems as their predominant symptoms were excluded. Three self-administered questionnaires were applied before an oesophagogastroduodenoscopy was performed. RESULTS: Among the 799 patients, 50.6% had a normal endoscopy. Endoscopic diagnoses comprised: non-erosive oesophagitis (7.5%), erosive oesophagitis (11.1%), Barrett's oesophagus (1.1%), gastritis/duodenitis (8.4%), gastric ulcer (4.5%), duodenal ulcer (8.3%), and cancer (1.3%). Non-dominant heartburn and acid regurgitation were significantly more common in patients with organic dyspepsia, whereas hunger pains and rumbling occurred more often in those with functional dyspepsia. Multivariate analyses demonstrated that younger age, female gender, high scores for hunger pain, rumbling, hard stools, low scores for heartburn, and acid regurgitation predicted functional dyspepsia. CONCLUSIONS: Self-administered questionnaires revealed differences in the symptom patterns between patients with functional and organic dyspepsia. Furthermore, the health-related well-being in patients with functional and organic dyspepsia centred was impaired to the same extent.


Subject(s)
Dyspepsia/etiology , Endoscopy, Gastrointestinal , Esophageal Diseases/diagnosis , Esophagoscopy , Gastrointestinal Diseases/diagnosis , Surveys and Questionnaires , Adolescent , Adult , Aged , Aged, 80 and over , Barrett Esophagus/diagnosis , Duodenitis/diagnosis , Esophageal Neoplasms/diagnosis , Esophagitis/diagnosis , Female , Gastritis/diagnosis , Gastrointestinal Neoplasms/diagnosis , Humans , Male , Middle Aged , Peptic Ulcer/diagnosis
11.
Scand J Gastroenterol ; 37(12): 1395-402, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12523588

ABSTRACT

BACKGROUND: Functional dyspepsia (FD) is defined as persistent or recurrent pain/discomfort centred in the upper abdomen, where no structural explanation for the symptoms is found. The role of drug treatment remains controversial. The aim in this study was to evaluate the effect of omeprazole 20 mg twice daily (b.i.d) and to test methods for symptom assessment. METHODS: 197 patients fulfilling the criteria for FD were randomly allocated to double-blind treatment with omeprazole 20 mg b.i.d (n = 100) or placebo (n = 97) for 14 days. Patients with a known gastrointestinal disorder or with main symptoms indicating gastro-oesophageal reflux disease or irritable bowel syndrome were excluded. Helicobacter pylori testing and 24-h intra-oesophageal 24-h pH-metry were performed before randomization. The patients recorded dyspeptic symptoms on diary cards. RESULTS: A stringent endpoint, 'complete symptom relief on the last day of treatment', was the primary efficacy variable. For the APT cohort, this was achieved in 29.0% and 17.7% on omeprazole and placebo, respectively (95% CI of difference (11.3%): -0.4%-23.0%, P = 0.057). Similar figures in the PP cohort were 31.0% and 15.5%, respectively (95% Cl of difference (15.5%): 3.2%-27.7%, P = 0.018). The benefit of omeprazole in the PP cohort was confirmed by secondary endpoints such as, no dyspeptic symptoms on the last 2 days of treatment and overall treatment response. H. pylori status and the level of oesophageal acid exposure did not significantly influence the response to therapy. CONCLUSION: A subset of patients with FD will respond to therapy with omeprazole.


Subject(s)
Anti-Ulcer Agents/therapeutic use , Dyspepsia/drug therapy , Omeprazole/therapeutic use , Adult , Aged , Anti-Ulcer Agents/administration & dosage , Double-Blind Method , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Monitoring, Physiologic , Omeprazole/administration & dosage
12.
Curr Opin Pharmacol ; 1(4): 404-8, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11710740

ABSTRACT

The development of genetic engineering technologies has today advanced to the point where the generation of high-affinity human antibodies against therapeutic targets is not a major hurdle. Rather, it is the selection of target molecules in, for example, cancer therapy that poses a challenge. Targets that are not merely passive acceptors but those that signal into the cell are preferred. Recent advances in the clinical use of antibody-based therapy--such as anti-CD20 (rituximab) for the treatment of non-Hodgkin's lymphoma and anti-tumour-necrosis-factor-alpha for Crohn's disease--as well as novel antibody designs and improved understanding of the mode of action of current antibodies lend great hope to the future of this therapeutic approach.


Subject(s)
Antibodies/therapeutic use , Neoplasms/therapy , Humans , Immunotherapy , Protein Engineering , Recombinant Proteins/therapeutic use
13.
J Cardiovasc Risk ; 8(4): 243-8, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11551003

ABSTRACT

BACKGROUND: The study was designed to determine whether a 1-year hospital-based secondary prevention programme would have any long-term effects on serum lipid levels and the use of lipid-lowering drugs in patients with coronary artery disease 4 years after referral to primary care facilities for follow-up. DESIGN/METHODS: After acute myocardial infarction or coronary bypass surgery, 241 consecutive patients were randomly assigned to conventional care (CC) by the primary health care facilities or to a 1-year hospital-based secondary prevention programme (SPP) with target levels for serum cholesterol (< 5.2 mmol/l) and triglycerides (< 1.5 mmol/l). After 1 year all patients were referred to the primary care sector for a further 4-year follow-up. RESULTS: At the 1-year follow-up there was a significant decrease in serum cholesterol, LDL-cholesterol and triglyceride levels in the SPP group but no change in the CC group, and lipid-lowering drugs were used more frequently in the SPP group. These changes were maintained after 5 years. The proportion of patients achieving target serum cholesterol and triglyceride levels were larger in the SPP group. CONCLUSIONS: Initiatives regarding cholesterol lowering and drug treatment taken by specialists within a structured hospital-based SPP have long-term impact. Accordingly, drug treatment should be initiated and adjusted to adequate doses before patients are referred to primary care for follow-up.


Subject(s)
Coronary Disease/drug therapy , Coronary Disease/prevention & control , Hypolipidemic Agents/therapeutic use , Aged , Chi-Square Distribution , Cholesterol/blood , Female , Follow-Up Studies , Humans , Male , Middle Aged , Program Evaluation , Time Factors , Triglycerides/blood
14.
Comb Chem High Throughput Screen ; 4(5): 409-16, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11472229

ABSTRACT

Technologies to develop and evolve the function of proteins and, in particular, antibodies have developed rapidly since the introduction of phage display. Importantly, it has become possible to identify molecules with binding properties that cannot be found by other means. A range of different approaches to create general libraries that are useful for the selection of such molecules specific for essentially any kind of target have emerged. We herein review some of the most prominent approaches in the field and in particular discuss specific features related to the development of antibody libraries based on single antibody framework scaffolds. This approach not only permits identification of a range of specific binders, but also facilitates further evolution of initially derived molecules into molecules with optimised functions.


Subject(s)
Antibodies/chemistry , Combinatorial Chemistry Techniques , Proteins/chemistry , Antibody Affinity , Complementarity Determining Regions
15.
Protein Eng ; 14(1): 67-74, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11287680

ABSTRACT

Antibody binding sites provide an adaptable surface capable of interacting with essentially any molecular target. Using CDR shuffling, residues important for the assembly of mucin-1 specific paratopes were defined by random recombination of the complementarity determining regions derived from a set of mucin-1 specific clones, previously selected from an antibody fragment library. It was found that positions 33 and 50 in the heavy chain and 32, 34, 90, 91 and 96 in the light chain were conserved in many of the clones. These particular residues seem to be located centrally in the binding site as indicated by a structure model analysis. The importance of several of these conserved residues was supported by their presence in a mouse monoclonal antibody with a known structure and the same epitope specificity. Several of these corresponding residues in the mouse monoclonal antibody are known to interact with the antigen. In conclusion, critical residues important for maintaining a human antigen-specific binding site during the process of in vitro antibody evolution were defined. Furthermore, an explanation for the observed restricted germline gene usage in certain antibody responses against protein epitopes is provided.


Subject(s)
Antibodies, Monoclonal/genetics , Complementarity Determining Regions/chemistry , Mucin-1/chemistry , Animals , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/metabolism , Binding Sites , Binding Sites, Antibody , Conserved Sequence , Epitopes/chemistry , Evolution, Molecular , Humans , Immunoglobulin Heavy Chains/genetics , Immunoglobulin Light Chains/genetics , Immunoglobulin Variable Region/chemistry , Mice , Models, Molecular , Molecular Sequence Data , Molecular Structure , Peptide Library , Protein Binding , Sequence Homology, Amino Acid , Tandem Repeat Sequences
16.
Am J Gastroenterol ; 96(1): 52-7, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11197287

ABSTRACT

OBJECTIVES: Brief, reliable, and valid self-administered questionnaires could facilitate the diagnosis of gastroesophageal reflux disease in primary care. We report the development and validation of such an instrument. METHODS: Content validity was informed by literature review, expert opinion, and cognitive interviewing of 50 patients resulting in a 22-item survey. For psychometric analyses, primary care patients completed the new questionnaire at enrollment and at intervals ranging from 3 days to 3 wk. Multitrait scaling, test-retest reliability, and responsiveness were assessed. Predictive validity analyses of all scales and items used specialty physician diagnosis as the "gold standard." RESULTS: Iterative factor analyses yielded three scales of four items each including heartburn, acid regurgitation, and dyspepsia. Multitrait scaling criteria including internal consistency, item interval consistency, and item discrimination were 100% satisfied. Test-retest reliability was high in those reporting stable symptoms. Scale scores significantly changed in those reporting a global change. Regressing specialty physician diagnosis on the three scales revealed significant effects for two scales (heartburn and regurgitation). Combining the two significant scales enhanced the strength of the model. Symptom response to self-directed treatment with nonprescription antisecretory medications was highly predictive of the diagnosis also, although the item demonstrated poor validity and reliability. CONCLUSIONS: A brief, simple 12-item questionnaire demonstrated validity and reliability and seemed to be responsive to change for reflux and dyspeptic symptoms.


Subject(s)
Gastroesophageal Reflux/diagnosis , Gastroesophageal Reflux/epidemiology , Surveys and Questionnaires/standards , Adult , Aged , Female , Health Surveys , Humans , Incidence , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
17.
Biochem J ; 354(Pt 2): 431-8, 2001 Mar 01.
Article in English | MEDLINE | ID: mdl-11171123

ABSTRACT

Immunoglobulin (Ig)-kappa promoters from humans and mice share conserved sequences. The octamer element is common to all Ig promoters and pivotal for their function. However, other conserved sequence motifs, that differ between Ig variable gene families, are required for normal promoter function. These conserved motifs do not stimulate transcription in the absence of an octamer. One example is an E-box of the E47/E12 type (5'-CAGCTG-3'), which is found in all promoters of the human and murine Ig-kappa gene subgroups/families, with the exception of subgroups II and VI and their related murine families. In the present study we show that the ubiquitously expressed transcription factor AP-4, and not E47, interacts specifically with the kappa promoter E-boxes when tested in electrophoretic mobility-shift assays using nuclear extracts derived from human and murine B-cell lines. Furthermore, AP-4, unlike E47, did not act as a transactivator, which is in agreement with previous studies on intact kappa promoters, showing that transcription is absent when the octamer element has been mutated. Based on these data, and the conservation of the 5'-CAGCTG-3' motif among human and murine kappa promoters, we propose that AP-4 is the major ligand for Ig-kappa promoter E-boxes.


Subject(s)
DNA-Binding Proteins/metabolism , Gene Expression Regulation , Helix-Loop-Helix Motifs , Immunoglobulin kappa-Chains/genetics , Promoter Regions, Genetic , Transcription Factors/metabolism , Animals , B-Lymphocytes/metabolism , Blotting, Western , Cells, Cultured , DNA/metabolism , Electrophoresis, Polyacrylamide Gel , HeLa Cells , Humans , Ligands , Mice , Protein Biosynthesis , Rabbits , TCF Transcription Factors , Transcription Factor 7-Like 1 Protein , Transcriptional Activation , Transfection
18.
Eur J Haematol ; 67(5-6): 309-17, 2001.
Article in English | MEDLINE | ID: mdl-11872079

ABSTRACT

Telomere length maintenance, usually executed by telomerase, is a prerequisite for an extended or infinite division potential. Nevertheless most telomerase positive normal cells exhibit telomere shortening. This study details the telomerase expression and telomere dynamics in purified tonsil B cell subsets during the germinal center (GC) reaction. Significant telomere lengthening was observed as naive B cells matured to centroblasts and when centroblasts matured further to centrocytes, resulting in an increase in telomere length of about 4 kbp determined by Southern blotting. Immunopurified cell populations were also studied by fluorescence in situ hybridization and flow cytometry (flow-FISH) confirming that the GC B cells exhibited lengthened telomeres. These data were further verified in unpurified tonsil cells by combining flow-FISH and immunophenotyping using selected surface markers. Centroblasts expressed high levels of telomerase activity, which was increased in centrocytes, whereas resting naive, activated naive and memory B cells were telomerase activity negative. Expression levels of the catalytic subunit (hTERT) RNA paralleled the telomerase activity levels. The unique telomere elongation in GC B cells permits extensive proliferation during the GC reaction and provides the memory cells with a substantial increase in division potential. Understanding the telomere biology of GC cells is important in defining requirements for telomere elongation in vivo, with implications for the normal immune system as well as for lymphomas, and could provide insights into how the division potential of cells can be manipulated in vitro.


Subject(s)
B-Lymphocyte Subsets/enzymology , Germinal Center/cytology , Germinal Center/enzymology , Telomerase/metabolism , Telomere/ultrastructure , Antigens, CD , B-Lymphocyte Subsets/ultrastructure , Flow Cytometry , Humans , Immunophenotyping , In Situ Hybridization, Fluorescence , Palatine Tonsil/enzymology , Palatine Tonsil/ultrastructure
19.
Expert Rev Mol Diagn ; 1(1): 102-8, 2001 May.
Article in English | MEDLINE | ID: mdl-11901793

ABSTRACT

The n-CoDeR recombinant antibody gene libraries are built on a single master framework, into which diverse in vivo-formed complementarity determining regions (CDRs) are allowed to recombine. These CDRs are sampled from in vivo-processed and proof-read gene sequences, thus ensuring an optimal level of correctly folded and functional molecules. By the modularized assembly process, up to six CDRs can be varied at the same time, providing a possibility for the creation of a hitherto undescribed genetic and functional variation. The n-CoDeR antibody gene libraries can be used to select highly specific, human antibody fragments with specificities to virtually any antigen, including carbohydrates and human self-proteins and with affinities down into the subnanomolar range. Furthermore, combining CDRs sampled from in vivo-processed sequences into a single framework result in molecules exhibiting a lower immunogenicity compared to normal human immunoglobulins, as determined by computer analyses. The distinguished features of the n-CoDeR libraries in the therapeutic and diagnostic areas are discussed.


Subject(s)
Antibodies/genetics , Gene Library , Animals , Antibodies/therapeutic use , Humans , Immunoglobulin Fragments/genetics , Oligonucleotide Array Sequence Analysis
20.
Immunology ; 101(2): 210-7, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11012774

ABSTRACT

Affinity maturation of antibody responses depends on somatic hypermutation of the immunoglobulin V genes. Hypermutation is initiated specifically in proliferating B cells in lymphoid germinal centres but the signals driving this process remain unknown. This study identifies signals that promote V gene mutation in human germinal centre (GC) B cells in vitro. Single GC B cells were cultured by limiting dilution to allow detection of mutations arising during proliferation in vitro. Cells were first cultured in the presence of CD32L cell transfectants and CD40 antibody (the 'CD40 system') supplemented with combinations of cytokines capable of supporting similar levels of CD40-dependent GC B-cell growth [interleukin (IL)-10 + IL-1beta + IL-2 and IL-10 + IL-7 + IL-4]. Components of the 'EL4 system' were then added to drive differentiation, providing sufficient immunoglobulin mRNA for analysis. Analysis of VH3 genes from cultured cells by reverse transcription-polymerase chain reaction (RT-PCR)-based single-strand conformation polymorphism indicated that the combination IL-10 + IL-1beta + IL-2 promoted active V gene mutation whereas IL-10 + IL-7 + IL-4 was ineffective. This was confirmed by sequencing which also revealed that the de novo generated mutations were located in framework and complementarity-determining regions and shared characteristics with those arising in vivo. Somatic mutation in the target GC B-cell population may therefore be actively cytokine driven and not simply a consequence of continued proliferation. The experimental approach we describe should facilitate further studies of the mechanisms underlying V gene hypermutation.


Subject(s)
B-Lymphocytes/immunology , Genes, Immunoglobulin , Germinal Center/immunology , Immunoglobulin Variable Region/genetics , Mutation/immunology , Cell Culture Techniques , Humans , Interleukins/immunology , Polymorphism, Single-Stranded Conformational , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/immunology
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