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1.
Breast Cancer Res Treat ; 187(3): 635-645, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33983492

RESUMO

BACKGROUND: Pre-treatment tumour-associated lymphocytes (TILs) and stromal lymphocytes (SLs) are independent predictive markers of future pathological complete response (pCR) in HER2-positive breast cancer. Whilst studies have correlated baseline lymphocyte levels with subsequent pCR, few have studied the impact of neoadjuvant therapy on the immune environment. METHODS: We performed TIL analysis and T-cell analysis by IHC on the pretreatment and 'On-treatment' samples from patients recruited on the Phase-II TCHL (NCT01485926) clinical trial. Data were analysed using the Wilcoxon signed-rank test and the Spearman rank correlation. RESULTS: In our sample cohort (n = 66), patients who achieved a pCR at surgery, post-chemotherapy, had significantly higher counts of TILs (p = 0.05) but not SLs (p = 0.08) in their pre-treatment tumour samples. Patients who achieved a subsequent pCR after completing neo-adjuvant chemotherapy had significantly higher SLs (p = 9.09 × 10-3) but not TILs (p = 0.1) in their 'On-treatment' tumour biopsies. In a small cohort of samples (n = 16), infiltrating lymphocyte counts increased after 1 cycle of neo-adjuvant chemotherapy only in those tumours of patients who did not achieve a subsequent pCR. Finally, reduced CD3 + (p = 0.04, rho = 0.60) and CD4 + (p = 0.01, rho = 0.72) T-cell counts in 'On-treatment' biopsies were associated with decreased residual tumour content post-1 cycle of treatment; the latter being significantly associated with increased likelihood of subsequent pCR (p < 0.01). CONCLUSIONS: The immune system may be 'primed' prior to neoadjuvant treatment in those patients who subsequently achieve a pCR. In those patients who achieve a pCR, their immune response may return to baseline after only 1 cycle of treatment. However, in those who did not achieve a pCR, neo-adjuvant treatment may stimulate lymphocyte influx into the tumour.


Assuntos
Neoplasias da Mama , Terapia Neoadjuvante , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Feminino , Humanos , Linfócitos , Linfócitos do Interstício Tumoral , Prognóstico , Receptor ErbB-2/genética
2.
Colorectal Dis ; 16(1): O16-25, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24119076

RESUMO

AIM: To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative. METHOD: One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection. RESULTS: Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively). CONCLUSION: Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.


Assuntos
Adenocarcinoma/patologia , Quimiorradioterapia , Linfonodos/patologia , Terapia Neoadjuvante , Neoplasias Retais/patologia , Adenocarcinoma/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/uso terapêutico , Intervalo Livre de Doença , Feminino , Fluoruracila/uso terapêutico , Humanos , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Neoplasias Retais/terapia , Indução de Remissão , Resultado do Tratamento , Carga Tumoral , Adulto Jovem
3.
Ir Med J ; 104(2): 58, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21465882

RESUMO

Inflammatory pseudotumours of the liver are extremely rare benign lesions. They were first described by Pack and Baker in 1953. They usually present with raised inflammatory markers and nonspecific abdominal symptoms. Most of these lesions are picked up incidentally on ultrasound scans. Diagnosis of these lesions poses a dilemma and a challenge due to their radiological similarities to other liver lesions such as hepatocellular carcinoma HCC. In this article we describe our experience in its diagnosis and management.


Assuntos
Granuloma de Células Plasmáticas/diagnóstico , Neoplasias Hepáticas/diagnóstico , Adulto , Granuloma de Células Plasmáticas/patologia , Granuloma de Células Plasmáticas/cirurgia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino
4.
Oncogene ; 27(3): 323-31, 2008 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-17621268

RESUMO

Molecular crosstalk, including reciprocal stimulation, is theorized to take place between epithelial cancer cells and surrounding non-neoplastic stromal cells. This is the rationale for stromal therapy, which could eliminate support of a cancer by its genetically stable stroma. Epithelial-stromal crosstalk is so far poorly documented in vivo, and cell cultures and animal experiments may not provide accurate models. The current study details stromal-epithelial signalling pathways in 35 human colon cancers, and compares them with matched normal tissues using quantitative proteomic microarrays. Lysates prepared from separately microdissected epithelium and stroma were analysed using antibodies against 61 cell signalling proteins, most of which recognize activated phospho-isoforms. Analyses using unsupervised and supervised statistical methods suggest that cell signalling pathway profiles in stroma and epithelium appear more similar to each other in tumours than in normal colon. This supports the concept that coordinated crosstalk occurs between epithelium and stroma in cancer and suggests epithelial-mesenchymal transition. Furthermore, the data herein suggest that it is driven by cell proliferation pathways and that, specifically, several key molecules within the mitogen-activated protein kinase pathway may play an important role. Given recent findings of epithelial-mesenchymal transition in therapy-resistant tumour epithelium, these findings could have therapeutic implications for colon cancer.


Assuntos
Carcinoma/metabolismo , Neoplasias do Colo/metabolismo , Proteínas de Neoplasias/metabolismo , Proteômica , Transdução de Sinais , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Proliferação de Células , Neoplasias do Colo/patologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Linfócitos , Masculino , Mesoderma/metabolismo , Mesoderma/patologia , Pessoa de Meia-Idade , Análise Serial de Proteínas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células Estromais/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo
5.
Ir Med J ; 99(7): 211, 213-4, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16986567

RESUMO

The adoption of the laparoscopic approach to colorectal resection has been slow amongst colorectal surgeons principally due to concerns regarding oncological safety. Recent randomized controlled trials have confirmed both the safe and some advantage of this procedure have been performing laparoscopic assisted colorectal resection since 2002 and have now performed over 100 cases on non consecutive and selected patients. We have reviewed our experience with the introduction of this technique. 61 patients were operated on for cancer and 39 for benign disease mainly Crohn's and diverticular disease. Operative time was a median of 128 minutes over the course of study. Conversion rate was 5%. Pathological analysis of the resected specimens in the cancer cases revealed adequate lymph node harvest and margins. No patient had a positive margin and no port site metastasis have been seen. Duration of ileus and length of stay were a median of 0 and 6 days. Post operative morbidity and mortality were comparable to open colorectal surgery with the exception of port site herniation which occurred in 4% of patients. This study suggests that a laparoscopic approach to colorectal resection can be successfully introduced in an Irish hospital setting. The challenge facing Irish surgery is to disseminate this technique in a controlled and safe manner for Irish patients.


Assuntos
Colectomia , Neoplasias Colorretais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colectomia/mortalidade , Colectomia/estatística & dados numéricos , Bases de Dados Factuais , Feminino , Unidades Hospitalares , Hospitais de Ensino , Humanos , Irlanda , Laparoscopia , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Taxa de Sobrevida
6.
J Pathol ; 208(5): 595-606, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16518808

RESUMO

The human proteome, due to the enormity of post-translational permutations that result in large numbers of isoforms, is much more complex than the genome and alterations in cancer can occur in ways that are not predictable by translational analysis alone. Proteomic analysis therefore represents a more direct way of investigating disease at the individual patient level. Furthermore, since most novel therapeutic targets are proteins, proteomic analysis potentially has a central role in patient care. At the same time, it is becoming clear that mapping entire networks rather than individual markers may be necessary for robust diagnostics as well as tailoring of therapy. Consequently, there is a need for high-throughput multiplexed proteomic techniques, with the capability of scanning multiple cases and analysing large numbers of endpoints. New types of protein arrays combined with advanced bioinformatics are currently being used to identify molecular signatures of individual tumours based on protein pathways and signalling cascades. It is envisaged that analysing the cellular 'circuitry' of ongoing molecular networks will become a powerful clinical tool in patient management.


Assuntos
Biomarcadores Tumorais/análise , Proteínas de Neoplasias/análise , Neoplasias/diagnóstico , Análise Serial de Proteínas/métodos , Humanos , Neoplasias/terapia , Proteômica/métodos
7.
Histopathology ; 46(3): 287-95, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15720414

RESUMO

AIM: In colorectal carcinomas, cyclooxygenase-2 (COX-2) is expressed predominantly by epithelial cells and is implicated in tumour progression. Tumour-associated macrophages may influence tumour growth, proliferative rate and angiogenesis and also express COX-2 when activated. Thus they may play an important stromal-epithelial role in carcinogenesis. Tauhe aim of this study was to define the relationship between microvessel density (MVD), tumour COX-2 and macrophage COX-2 expression. METHODS AND RESULTS: Sixty-five cases of formalin-fixed paraffin-embedded colorectal cancer were included in the study. Tissues were immunostained for COX-2, CD68 (macrophage marker) and CD34 (endothelial marker to assess MVD). Thirty-six cases were grossly ulcerated cancers and 29 cases showed focal/microscopic ulceration. Macrophages were in high concentration at the base of ulcerated areas, and were also diffusely dispersed within tumoral stroma. However, the pattern of macrophage COX-2 expression revealed two populations of macrophages--those deep within the tumour (negative for COX-2) and those at the base of ulcers (positive for COX-2). In all cases, the tumour epithelial cells expressed COX-2. MVD was higher at the base of ulcers, adjacent to COX-2+ macrophages, and was lower deep within the tumour. CONCLUSIONS: In colorectal cancers, macrophages may have a dual role. Those concentrated at the base of the ulcers, where there is an associated high MVD, may induce angiogenesis, but their function may be in a healing/repair process. The lack of COX-2+ macrophages and lower MVD deep within the tumour suggests that it may be the epithelial COX-2 component that is important in tumour progression.


Assuntos
Neoplasias Colorretais/patologia , Macrófagos/patologia , Neovascularização Patológica/patologia , Prostaglandina-Endoperóxido Sintases/biossíntese , Úlcera/patologia , Antígenos CD/análise , Antígenos CD34/análise , Antígenos de Diferenciação Mielomonocítica/análise , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/metabolismo , Ciclo-Oxigenase 2 , Epitélio/enzimologia , Epitélio/patologia , Humanos , Imuno-Histoquímica , Macrófagos/enzimologia , Proteínas de Membrana , Neovascularização Patológica/metabolismo
8.
Br J Surg ; 91(12): 1613-8, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15505871

RESUMO

BACKGROUND: Selective inhibitors of inducible cyclo-oxygenase (COX-2) are of potential benefit in the perioperative period for both their analgesic and, perhaps, antineoplastic actions. However, their effects on laparotomy and intestinal wound healing are unknown. METHODS: Forty adult Sprague-Dawley rats underwent laparotomy, descending colonic transection and handsewn reanastomosis. The animals were randomized to receive either a selective COX-2 inhibitor (rofecoxib, 10 mg/kg) or an equal volume of water by gavage before operation and then daily after surgery. Animals were killed after 3 or 7 days, and their wounds were evaluated by means of tensiometry (skin and colonic wounds) and bursting pressure measurement (colonic anastomoses). In addition, haematoxylin and eosin-stained intestinal sections were examined and scored by a blinded independent observer. RESULTS: Five animals that received rofecoxib had anastomotic leaks by day 7 compared with none in the control group (P = 0.048). Intact colonic suture lines were also significantly weaker in this group (tensile strength at day 3, P = 0.043; bursting pressure on days 3 and 7, both P = 0.019). Skin wound strengths were similar in the two groups at both time points. CONCLUSION: Although beneficial in the treatment of pathological inflammation, selective COX-2 inhibitors may adversely affect colonic anastomotic healing.


Assuntos
Colo/cirurgia , Inibidores de Ciclo-Oxigenase/farmacologia , Isoenzimas/antagonistas & inibidores , Cicatrização/efeitos dos fármacos , Anastomose Cirúrgica , Animais , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Masculino , Prostaglandina-Endoperóxido Sintases , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
9.
Dig Liver Dis ; 36(6): 392-7, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15248379

RESUMO

BACKGROUND: Both the expressions of the inducible form of cyclooxygenase-2 and the presence of bone marrow micrometastases are poor prognostic markers in patients with colorectal carcinoma. AIMS: As cyclooxygenase-2 expression in these tumours is associated with increased metastatic potential in vitro, our objectives were to determine the relationship between cyclooxygenase-2 and haematogenous spread to bone marrow. PATIENTS AND METHODS: Thirty-two patients with resection of colorectal carcinoma were evaluated (median age: 69.5 years). Bone marrow was obtained from all patients from both iliac crests before manipulation of the primary tumour. The tumours were of varying stages at diagnosis (5 Dukes' A, 14 Dukes' B, 11 Dukes' C and 2 Dukes' D). Tumour sections were stained for cyclooxygenase-2 using the avidin-biotin immunohistochemical technique. Extent of staining was graded depending on the percentage of epithelial cells staining positive for cyclooxygenase-2. Micrometastases were detected by staining contaminant cytokeratin-18 positive cells in the bone marrow aspirates by either immunohistochemical (ARAAP) or immunological (flow cytometry) methods. Fisher's exact probability test was used to calculate statistical significance. RESULTS: Cyclooxygenase-2 expression in the primary tumour was detected in 72% of the patients. Twelve (38%) patients had bone marrow micrometastases detected by either immunohistochemistry or flow cytometry. Of the 12 patients who had bone marrow micrometastases, 8 tumours demonstrated increased expression of cyclooxygenase-2 protein (66.6%). In contrast, 9 out of the 20 (45%) patients in whom micrometastases were not detected expressed increased levels of cyclooxygenase-2 (P = 0.29). When dividing the patients into subgroups of localised (Dukes' A and B) versus disseminated (Dukes' C and D) disease, there was no further association between cyclooxygenase-2 expression and bone marrow micrometastases (P = 0.179 and 1.0). CONCLUSION: In this pilot study, there was no association between cyclooxygenase-2 expression and bone marrow micrometastases in patients with otherwise localised or disseminated disease.


Assuntos
Neoplasias da Medula Óssea/enzimologia , Neoplasias da Medula Óssea/secundário , Neoplasias Colorretais/enzimologia , Isoenzimas/biossíntese , Prostaglandina-Endoperóxido Sintases/biossíntese , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Medula Óssea/patologia , Neoplasias Colorretais/patologia , Ciclo-Oxigenase 2 , Células Epiteliais/enzimologia , Feminino , Citometria de Fluxo , Humanos , Técnicas Imunoenzimáticas , Masculino , Proteínas de Membrana , Pessoa de Meia-Idade , Peroxidases/biossíntese , Projetos Piloto
10.
J Clin Pathol ; 57(3): 312-3, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14990607

RESUMO

Aneurysmal fibrous histiocytoma is a rare variant of cutaneous fibrous histiocytoma that results from blood vessel proliferation and haemorrhage into a fibrous histiocytoma. The resulting lesion has a very different clinical appearance, hence the potential confusion with other skin lesions. This report describes the case of a 48 year old woman with a recurrent fibrous histiocytoma with prominent vasculature, which over a three year period recurred on two occasions, showing more progressive features of the aneurysmal variant. In addition, squamous lined cysts were present within this tumour, a finding that has not been described previously. The histological features of this rare lesion and the importance of the differential diagnosis from other similar appearing malignant lesions will be discussed.


Assuntos
Histiocitoma Fibroso Benigno/patologia , Neoplasias Cutâneas/patologia , Cistos/diagnóstico , Cistos/patologia , Diagnóstico Diferencial , Feminino , Histiocitoma Fibroso Benigno/diagnóstico , Humanos , Perna (Membro) , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Neoplasias Cutâneas/diagnóstico
11.
J Clin Pathol ; 56(6): 478-9, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12783979

RESUMO

This report describes a case of well differentiated fetal adenocarcinoma of the lung in a 29 year old female smoker. The histological pattern and immunohistochemical profile were consistent with well differentiated fetal adenocarcinoma and the patient made an uneventful postoperative recovery with no recurrence after 18 months. This neoplasm is a rare lung tumour that is composed of glycogen rich neoplastic glands and tubules that resembles fetal lung at 10 to 15 weeks of gestation. It is important to identify this rare variant of adenocarcinoma because it is a low grade malignancy with low associated mortality.


Assuntos
Adenocarcinoma/patologia , Neoplasias Pulmonares/patologia , Adulto , Diferenciação Celular , Diagnóstico Diferencial , Feminino , Feto/patologia , Seguimentos , Humanos , Prognóstico , Blastoma Pulmonar/diagnóstico
12.
JAMA ; 282(13): 1254-7, 1999 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-10517428

RESUMO

CONTEXT: Epidemiological studies have implicated the inducible form of cyclooxygenase (COX-2) in the pathogenesis of colorectal cancer; however, its role is not fully understood. OBJECTIVE: To examine the relationship between the expression of COX-2 in human colorectal cancer and patient survival. DESIGN: Patients diagnosed as having colorectal cancer were evaluated and followed up for up to 9.4 years (median follow-up, 2.7 years). Tumor sections were stained for COX-2 using a rabbit polyclonal antibody raised against human COX-2. The extent of COX-2 staining was graded by 2 observers blinded to outcome. Preabsorption of the anti-COX-2 antibody with a COX-2 peptide abolished the staining, demonstrating the specificity of the assay. SETTING: Gastrointestinal unit of a large general teaching hospital in Dublin, Ireland. PARTICIPANTS: Seventy-six patients (median age, 66.5 years) with colorectal cancer (Dukes tumor stage A, n = 9; Dukes B, n = 30; Dukes C, n = 25; Dukes D, n = 12) whose diagnosis was made between 1988 and 1991. Fourteen normal colon biopsies were stained for COX-2 as controls. MAIN OUTCOME MEASURES: Survival in years following diagnosis compared by extent of COX-2 epithelial staining (grade 1, <1%; grade 2, 1%-19%; grade 3, 20%-49%; grade 4, > or = 50%), Dukes stage, tumor size, and lymph mode metastasis. RESULTS: COX-2 was found in tumor epithelial cells, inflammatory cells, vascular endothelium, and/or fibroblasts. The extent of epithelial staining was heterogeneous, varying markedly among different tumors. Normal tissue adjacent to the tumors also stained weakly for COX-2. No COX-2 was detected in control tissue samples. The Kaplan-Meier survival estimate was 68% in patients who had grade 1 tumor epithelial staining compared with 35% in those with higher grades combined (log-rank chi2 = 5.7; P = .02). Greater expression of COX-2 correlated with more advanced Dukes stage (Kendall tau-b, 0.22; P = .03) and larger tumor size (Kendall tau-b, 0.21; P = .02) and was particularly evident in tumors with lymph node involvement (Kendall tau-b, 0.26; P = .02). CONCLUSIONS: Our data indicate that COX-2 expression in colorectal cancer may be related to survival. These data add to the growing epidemiological and experimental evidence that COX-2 may play a role in colorectal tumorigenesis.


Assuntos
Neoplasias Colorretais/química , Isoenzimas/análise , Prostaglandina-Endoperóxido Sintases/análise , Idoso , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Ciclo-Oxigenase 2 , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Proteínas de Membrana , Estadiamento de Neoplasias , Prognóstico , Análise de Sobrevida
13.
Mol Cell Biol ; 13(3): 1363-70, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8441381

RESUMO

V(D)J recombination in lymphoid cells is a site-specific process in which the activity of the recombinase enzyme is targeted to signal sequences flanking the coding elements of antigen receptor genes. The order of the steps in this reaction and their mechanistic interdependence are important to the understanding of how the reaction fails and thereby contributes to genomic instability in lymphoid cells. The products of the normal reaction are recombinant joints linking the coding sequences of the receptor genes and, reciprocally, the signal ends. Extrachromosomal substrate molecules were modified to inhibit the physical synapsis of the recombination signals. In this way, it has been possible to assess how inhibiting the formation of one joint affects the resolution efficiency of the other. Our results indicate that signal joint and coding joint formation are resolved independently in that they can be uncoupled from each other. We also find that signal synapsis is critical for the generation of recombinant products, which greatly restricts the degree of potential single-site cutting that might otherwise occur in the genome. Finally, inversion substrates manifest synaptic inhibition at much longer distances than do deletion substrates, suggesting that a parallel rather than an antiparallel alignment of the signals is required during synapsis. These observations are important for understanding the interaction of V(D)J signals with the recombinase. Moreover, the role of signal synapsis in regulating recombinase activity has significant implications for genome stability regarding the frequency of recombinase-mediated chromosomal translocations.


Assuntos
Linfócitos B/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Integrases , Receptores de Antígenos de Linfócitos B/genética , Receptores de IgG/genética , Recombinação Genética , Animais , Células Cultivadas , Inversão Cromossômica , DNA Nucleotidiltransferases/metabolismo , Sondas de DNA , DNA Recombinante/genética , Meiose , Camundongos , Modelos Genéticos , Conformação de Ácido Nucleico , Oligonucleotídeos/metabolismo , Plasmídeos/genética , Recombinases , Transfecção
14.
Eur J Immunol ; 19(11): 2115-21, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2480903

RESUMO

Previously we have shown that a high proportion (5%-15%) of peritoneal Ly-1+ B cells that bind the common membrane phospholipid, phosphatidylcholine, express either of two VH genes. One of these genes, CH34VH, belongs to the recently described VH11 family, whereas the other VH gene, CH27VH, is reported here to belong to a new, single-member family which we designate VH12. We have characterized these new VH families in terms of strain polymorphism, map position relative to nine other VH gene families, and frequency of expression in polyclonally stimulated splenic B cell populations. We find that VH11 and VH12 genes are expressed at frequencies similar to the VH genes of other families in the spleen, and that these genes are not located among the J-proximal VH segments which are preferentially expressed during early development. These results suggest that the VH11 and VH12 genes are not preferentially rearranged, and support our earlier studies which suggested that the high frequency of VH11 and VH12 expression among peritoneal Ly-1 B cells is due to antigen selection.


Assuntos
Antígenos de Diferenciação/análise , Antígenos Ly/análise , Linfócitos B/fisiologia , Genes de Imunoglobulinas , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Animais , Sequência de Bases , Southern Blotting , Antígenos CD5 , Mapeamento Cromossômico , Rearranjo Gênico de Cadeia Pesada de Linfócito B , Camundongos , Dados de Sequência Molecular , Família Multigênica , Polimorfismo de Fragmento de Restrição , Baço/citologia
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