Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Cancer ; 128(9): 1820-1825, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35128638

RESUMO

BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer-related death in Hispanic patients. Screening colonoscopy has been shown to reduce the incidence and mortality of CRC. However, utilization among Hispanic patients and other minority groups is low. The objective of this study was to evaluate colonoscopy utilization among Hispanic patients with a culturally tailored patient navigation program (CTPNP) in place. METHODS: A CTPNP was designed to meet the needs of the authors' Hispanic patient population and their health care system characteristics. A CTPNP protocol was created, and a Spanish-speaking navigator/coordinator was hired. Enrolled patients received a Spanish-language introductory letter, an initial phone call for patient education, and follow-up calls to ensure that all potential barriers to colonoscopy were overcome. Colonoscopy completion (CC), colonoscopy cancellation (CN), and colonoscopy no-show (NS) rates were recorded and compared with historical rates in Rhode Island. RESULTS: Over a 28-month period, 773 patients were referred to the CTPNP, and 698 (53% female and 47% male) were enrolled in the program. The overall CC rate was 85% (n = 592) with no difference between males and females. The CN rate was 9% (n = 62), and the NS rate was 6% (n = 44). The most common reasons for CN and NS were cost and an inability to contact the patient after referral. Within the CC group, 43% (n = 254) of patients underwent polypectomy, and 1.3% (n = 8) required colectomy. Ninety percent (n = 530) of the CC group reported that they would not have completed colonoscopy without the CTPNP. CONCLUSIONS: Implementation of a CTPNP is an effective intervention to improve the CC rate and eliminate the historical gender gap in utilization among Hispanic patients.


Assuntos
Neoplasias Colorretais , Navegação de Pacientes , Colonoscopia , Neoplasias Colorretais/epidemiologia , Detecção Precoce de Câncer/métodos , Feminino , Hispânico ou Latino , Humanos , Masculino , Programas de Rastreamento , Navegação de Pacientes/métodos
2.
J Surg Res ; 272: 37-50, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34929499

RESUMO

BACKGROUND: Effective treatment of solid tumors requires multi-modality approaches. In many patients with stage IV liver disease, current treatments are not curative. Chimeric antigen receptor T cells (CAR-T) are an intriguing option following success in hematological malignancies, but this has not been translated to solid tumors. Limitations include sub-optimal delivery and elevated interstitial fluid pressures. We developed a murine model to test the impact of high-pressure regional delivery (HPRD) on trafficking to liver metastases (LM) and tumor response. MATERIALS AND METHODS: CAR-T were generated from CD45.1 mice and adoptively transferred into LM-bearing CD45.2 mice via regional or systemic delivery (RD, SD). Trafficking, tumor growth, and toxicity were evaluated with flow cytometry, tumor bioluminescence (TB, photons/sec log2-foldover baseline), and liver function tests (LFTs). RESULTS: RD of CAR-T was more effective at controlling tumor growth versus SD from post-treatment days (PTD) 2-7 (P = 0.002). HPRD resulted in increased CAR-T penetration versus low-pressure RD (LPRD, P = 0.004), suppression of tumor proliferation (P = 0.03), and trended toward improved long-term control at PTD17 (TB=3.7 versus 6.1, P = 0.47). No LFT increase was noted utilizing HPRD versus LPRD (AST/ALT P = 0.65/0.84) while improved LFTs in RD versus SD groups suggested better tumor control (HPRD AST/ALT P = 0.04/0.04, LPRD AST/ALT P = 0.02/0.02). CONCLUSIONS: Cellular immunotherapy is an emerging option for solid tumors. Our model suggests RD and HPRD improved CAR-T penetration into solid tumors with improved short-term tumor control. Barriers associated with SD can be overcome using RD techniques to maximize therapeutic delivery and HPRD may further augment efficacy without increased toxicity.


Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Neoplasias , Receptores de Antígenos Quiméricos , Animais , Neoplasias Colorretais/terapia , Humanos , Imunoterapia Adotiva/métodos , Neoplasias Hepáticas/patologia , Camundongos , Neoplasias/terapia , Linfócitos T
3.
Vaccines (Basel) ; 9(8)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34451932

RESUMO

Metastatic liver tumors have presented challenges with the use of checkpoint inhibitors (CPIs), with only limited success. We hypothesize that regional delivery (RD) of CPIs can improve activity in the liver and minimize systemic exposure, thereby reducing immune-related adverse events (irAE). Using a murine model of colorectal cancer liver metastases (LM), we confirmed high levels of PD-L1 expression on the tumor cells and liver myeloid-derived suppressor cells (L-MDSC). In vivo, we detected improved LM response at 3 mg/kg on PTD7 via portal vein (PV) regional delivery as compared to 3 mg/kg via tail vein (TV) systemic delivery (p = 0.04). The minimal effective dose at PTD7 was 5 mg/kg (p = 0.01) via TV and 0.3 mg/kg (p = 0.02) via PV. We detected 6.7-fold lower circulating CPI antibody levels in the serum using the 0.3 mg/kg PV treatment compared to the 5 mg/kg TV cohort (p < 0.001) without increased liver toxicity. Additionally, 3 mg/kg PV treatment resulted in increased tumor cell apoptotic signaling compared to 5 mg/kg TV (p < 0.05). Therefore, RD of an anti-PD-1 CPI therapy for CRCLM may improve the therapeutic index by reducing the total dose required and limiting the systemic exposure. These advantages could expand CPI indications for liver tumors.

4.
J Immunother Cancer ; 8(2)2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32843493

RESUMO

In recent years, cell therapy technologies have resulted in impressive results in hematologic malignancies. Treatment of solid tumors with chimeric antigen receptor T-cells (CAR-T) has been less successful. Solid tumors present challenges not encountered with hematologic cancers, including high intra-tumoral pressure and ineffective CAR-T trafficking to the site of disease. Novel delivery methods may enable CAR-T therapies for solid tumor malignancies. A patient with liver metastases secondary to pancreatic adenocarcinoma received CAR-T targeting carcinoembryonic antigen (CEA). Previously we reported that Pressure-Enabled Drug Delivery (PEDD) enhanced CAR-T delivery to liver metastases 5.2-fold. Three doses of anti-CEA CAR-T were regionally delivered via hepatic artery infusion (HAI) using PEDD technology to optimize the therapeutic index. Interleukin-2 was systemically delivered by continuous intravenous infusion to support CAR-T in vivo. HAI of anti-CEA CAR-T was not associated with any serious adverse events (SAEs) above grade 3 and there were no on-target/off-tumor SAEs. Following CAR-T treatment, positron emission tomography-CT demonstrated a complete metabolic response within the liver, which was durable and sustained for 13 months. The response was accompanied by normalization of serum tumor markers and an abundance of CAR+ cells found within post-treatment tumor specimens. The findings from this report exhibit biologic activity and safety of regionally infused CAR-T for an indication with limited immune-oncology success to date. Further studies will determine how HAI of CAR-T may be included in multidisciplinary treatment plans for patients with liver metastases. ClinicalTrials.gov number, NCT02850536.


Assuntos
Neoplasias Hepáticas/genética , Sistemas de Liberação de Medicamentos , Humanos , Imunoterapia/métodos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos Quiméricos/metabolismo , Microambiente Tumoral
5.
J Opioid Manag ; 15(4): 307-322, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31637683

RESUMO

BACKGROUND: Increasing opioid-related deaths have heightened focus on combating the opioid epidemic. The impact of surgical trainees on opioid-related deaths is unclear, and there is little data examining the association between trainee pain management education and opioid prescribing practices. METHODS: An anonymous, online survey was distributed to members of the Resident and Associate Society of the American College of Surgeons. The survey covered five themes: education and knowledge, prescribing practices, clinical case scenarios, policy, and beliefs and attitudes. Linear mixed models were used to evaluate the influence of respondent characteristics on reported morphine milligram equivalents (MME) prescribed for common general surgery clinical scenarios. RESULTS: Of 427 respondents, 54 percent indicated receiving training in postoperative pain management during medical school and 66 percent during residency. Only 35 percent agreed that they had received adequate training in prescribing opioids. There was a significant association between undergoing formal pain management training in medical school and prescribing fewer MME for common outpatient general surgery scenarios (94 ± 15.2 vs 108 ± 15.0; p = 0.003). Similarly, formal pain management training in residency was associated with prescribing fewer MME in the survey scenarios (92.6 ± 15.2 vs 109 ± 15.2; p = 0.002). CONCLUSION: In this survey, nearly two-thirds of surgical residents felt that they were inadequately trained in opioid pre-scribing. Our findings additionally suggest that improving education may result in increased resident comfort with man-aging surgical pain, potentially leading to more responsible opioid prescribing. Further work will facilitate residency pro-grams' development of educational curricula for opioid prescribing best practices.


Assuntos
Analgésicos Opioides , Prescrições de Medicamentos , Cuidados Pós-Operatórios/métodos , Padrões de Prática Médica , Analgésicos Opioides/administração & dosagem , Prescrições de Medicamentos/estatística & dados numéricos , Feminino , Humanos , Masculino , Inquéritos e Questionários
6.
Surgery ; 164(6): 1351-1359, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30037428

RESUMO

BACKGROUND: Adrenocortical oncocytic neoplasms are rare tumors, generally regarded as benign and hormonally nonfunctional. We performed a systematic review to update the literature on adrenocortical oncocytic neoplasms by reviewing patient and tumor characteristics, as well as management trends, because the literature is composed of predominately single-case reports. METHODS: A systematic search was performed in PubMed, Embase, and Cochrane Library through June 2017. Malignant potential was determined by applying the Lin-Weiss-Bisceglia criteria to cases. RESULTS: Included for analysis were 84 citations describing 140 adrenocortical oncocytic neoplasms, including our own case. These were diagnosed predominantly in females (66%), on the left side (64%), and were nonfunctional (66%). Average age at diagnosis was 44 years (2.5-77), and median tumor size was 80 mm (16-285). A total of 35% of adrenocortical oncocytic neoplasms were benign, 41% borderline, and 24% malignant. Male patients were more likely to have a malignant tumor compared with females (36% versus 18%, P = .035). The 5-year overall survival for benign adrenocortical oncocytic neoplasms was 100%, borderline 88%, and malignant 47%. Hormonal function did not discriminate malignant from benign lesions. Adrenocortical oncocytic neoplasms that stained positive for synaptophysin (50%, P < .001) and negative for vimentin (62%, P = .009) are more often benign. CONCLUSION: We found that the majority of adrenocortical oncocytic neoplasms (65%) were either malignant or had malignant potential, contrary to the previous literature. The Lin-Weiss-Bisceglia criteria are useful in identifying those patients for whom closer surveillance is warranted, because their prognosis is dependent on the Lin-Weiss-Bisceglia diagnosis.


Assuntos
Neoplasias do Córtex Suprarrenal/patologia , Córtex Suprarrenal/patologia , Neoplasias do Córtex Suprarrenal/mortalidade , Neoplasias do Córtex Suprarrenal/terapia , Adulto , Feminino , Humanos
8.
J Am Coll Surg ; 227(1): 64-76, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29551697

RESUMO

BACKGROUND: It is increasingly important for faculty to teach deliberately and provide timely, detailed, and formative feedback on surgical trainee performance. We initiated a multicenter study to improve resident evaluative processes and enhance teaching and learning behaviors while engaging residents in their education. STUDY DESIGN: Faculty from 7 US postgraduate training programs rated resident operative performances using the perioperative briefing, intraoperative teaching, debriefing model, and rated patient visits/academic performances using the entrustable professional activities model via a web-based platform. Data were centrally analyzed and iterative changes made based on participant feedback, individual preferences, and database refinements, with trends addressed using the Plan, Do, Check, Act improvement methodology. RESULTS: Participants (92 surgeons, 150 residents) submitted 3,880 assessments during July 2014 through September 2017. Evidence of preoperative briefings improved from 33.9% ± 2.5% to 95.5% ± 1.5% between April and September 2014 compared with April and September 2017 (p < 0.001). Postoperative debriefings improved from 10.6% ± 2.7% to 90.2% ± 2.5% (p < 0.001) for the same period. Meaningful self-reflection by residents improved from 28.6% to 67.4% (p < 0.001). The number of assessments received per resident during a 6-month period increased from 6.4 ± 6.2 to 13.4 ± 10.1 (p < 0.003). Surgeon-entered assessments increased from 364 initially to 685 in the final period, and the number of resident assessments increased from 308 to 445. We showed a 4-fold increase in resident observed activities being rated. CONCLUSIONS: By adopting recognized educational models with repeated Plan, Do, Check, Act cycles, we increased the quality of preoperative learning objectives, showed more frequent, detailed, and timely assessments of resident performance, and demonstrated more effective self-reflection by residents. We monitored trends, identified opportunities for improvement and successfully sustained those improvements over time, applying a team-based approach.


Assuntos
Educação de Pós-Graduação em Medicina/organização & administração , Cirurgia Geral/educação , Internet , Internato e Residência , Melhoria de Qualidade , Avaliação Educacional , Feedback Formativo , Humanos , Michigan , Modelos Educacionais , Desenvolvimento de Programas , Estados Unidos
10.
Am J Surg ; 214(3): 564-570, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28259204

RESUMO

BACKGROUND: We studied prevalence and predictors of meaningful self-reflection among surgical residents and with prompting/structured interventions, sought to improve/sustain resident skills. METHODS: Residents from six programs recorded 1032 narrative self-reflective comments (120 residents), using a web-based platform. If residents identified something learned or to be improved, self-reflection was deemed meaningful. Independent variables PGY level, resident/surgeon gender, study site/Phase1: July2014-August2015 vs. Phase2: September2015-September2016) were analyzed. RESULTS: Meaningful self-reflection was documented in 40.6% (419/1032) of entries. PGY5's meaningfully self-reflected less than PGY1-4's, 26.1% vs. 49.6% (p = 0.002). In multivariate analysis, resident narratives during Phase 2 were 4.7 times more likely to engage in meaningful self-reflection compared to Phase1 entries (p < 0.001). Iterative changes during Phase2 showed a 236% increase in meaningful self-reflection, compared to Phase1. CONCLUSIONS: Surgical residents uncommonly practice meaningful self-reflection, even when prompted, and PGY5/chief residents reflect less than more junior residents. Substantial/sustained improvements in resident self-reflection can occur with both training and interventions.


Assuntos
Internato e Residência , Autoavaliação (Psicologia) , Especialidades Cirúrgicas/educação , Feminino , Humanos , Masculino , Período Perioperatório , Melhoria de Qualidade
11.
Am J Surg ; 213(2): 282-287, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28139201

RESUMO

BACKGROUND: Gender and/or gender-stereotypes might influence surgical education. We hypothesized that female surgeons might focus their learning and teaching differently from male surgeons. METHODS: Residents and surgeons (multi-institutional) individually recorded preoperatively discussed learning objectives (LO) for matching cases. Narratives were classified as knowledge-based, skill-based, or attitude-based. Multinomial logistic regression analyses, LO = dependent variable; independent variables = resident/surgeon gender, PGY level, timing of entry-to-procedure date, and quarters-of-year. RESULTS: 727 LOs from 125 residents (41% female) and 49 surgeons (20% female) were classified. Female residents were 1.4 times more likely to select knowledge over skill. With female surgeons, residents were 1.6 and 2.1 times more likely to select knowledge over skill and attitude over skill than if the surgeon was male. PGY 4/5 residents chose attitude-based LOs over junior residents. CONCLUSION: Resident, surgeon gender and year-of-training influence learning objectives. Whether this reflects gender stereotyping by residents or differences in attending teaching styles awaits further exploration.


Assuntos
Aprendizagem , Médicas , Cirurgiões , Ensino , Atitude do Pessoal de Saúde , Competência Clínica , Docentes de Medicina , Feminino , Cirurgia Geral/educação , Humanos , Internato e Residência , Masculino , Estados Unidos
12.
Am J Surg ; 213(2): 260-267, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28062076

RESUMO

BACKGROUND: Resident and curriculum evaluation require tracking surgical resident operative performance, yet what and when to measure remains unclear. METHODS: From a multi-institutional database, we reviewed 611 resident/surgeon-paired assessments of ACGME Milestones and modified OPRS ratings for different cases and postgraduate years. RESULTS: Faculty Milestone ratings increased with each PGY (p=<0.001) and correlated with resident self-ratings (ICC = 0.83). Mean OPRS scores increased in small increments with substantial intra-year variability. Progression among individual OPRS subcategories was not apparent from more global analyses. Interestingly, male faculty offered lower ratings than female faculty. CONCLUSIONS: Milestones and modified mean OPRS ratings suggest residents are learning, yet lack sufficient discrimination for promotion or curricular analysis. Differential progression through OPRS subcategories suggests a taxonomy of surgical learning that can be tailored to focus on different skills at each point in the training continuum. The effect of faculty gender on resident ratings awaits further study.


Assuntos
Competência Clínica , Avaliação Educacional/métodos , Cirurgia Geral/educação , Internato e Residência , Currículo , Bases de Dados Factuais , Educação de Pós-Graduação em Medicina , Docentes de Medicina , Feminino , Humanos , Masculino , Estados Unidos
14.
Eur J Immunol ; 44(3): 842-55, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24281978

RESUMO

In this study, we examined the role IL-13 receptor alpha 1 (IL-13Rα1) plays in macrophage differentiation and function. The findings indicate that IL-13Rα1 is expressed on the M2 but not on the M1 subset of macrophages and specifically heterodimerizes with the IL-4Rα chain to form a type II receptor, which controls the differentiation and function of these cells. Indeed, BM cells from IL-13Rα1(+/+) and IL-13Rα1(-/-) mice yield equivalent numbers of macrophages when cultured under M2 polarizing conditions. However, IL-13Rα1(-/-) BM cells yield a much higher number of macrophages than IL-13Rα1(+/+) BM cells when the differentiation is carried out under M1-polarizing conditions. Further analyses indicated that macrophages that express IL-13Rα1 also display surface markers associated with an M2 phenotype. In addition, the IL-13Rα1(+) macrophages were highly efficient in phagocytizing zymosan bioparticles both in vitro and in vivo, and supported differentiation of naïve T cells to a Th2 phenotype. Finally, when stimulated by IL-13, a cytokine that uses the heteroreceptor, the cells were able to phosphorylate STAT6 efficiently. These previously unrecognized findings indicate that IL-13Rα1 serves as a marker for M2 macrophages and the resulting heteroreceptor influences both their differentiation and function.


Assuntos
Subunidade alfa1 de Receptor de Interleucina-13/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Expressão Gênica , Imunofenotipagem , Interleucina-13/farmacologia , Subunidade alfa1 de Receptor de Interleucina-13/genética , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Knockout , Monócitos/imunologia , Monócitos/metabolismo , Fenótipo , Fosforilação/efeitos dos fármacos , Característica Quantitativa Herdável , Fator de Transcrição STAT6/metabolismo
15.
J Immunol ; 188(7): 3208-16, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22351937

RESUMO

The earliest thymic progenitors (ETPs) were recently shown to give rise to both lymphoid and myeloid cells. Whereas the majority of ETPs are derived from IL-7Rα-positive cells and give rise exclusively to T cells, the origin of the myeloid cells remains undefined. In this study, we show both in vitro and in vivo that IL-13Rα1(+) ETPs yield myeloid cells with no potential for maturation into T cells, whereas IL-13Rα1(-) ETPs lack myeloid potential. Moreover, transfer of lineage-negative IL-13Rα1(+) bone marrow stem cells into IL-13Rα1-deficient mice reconstituted thymic IL-13Rα1(+) myeloid ETPs. Myeloid cells or macrophages in the thymus are regarded as phagocytic cells whose function is to clear apoptotic debris generated during T cell development. However, the myeloid cells derived from IL-13Rα1(+) ETPs were found to perform Ag-presenting functions. Thus, IL-13Rα1 defines a new class of myeloid restricted ETPs yielding APCs that could contribute to development of T cells and the control of immunity and autoimmunity.


Assuntos
Células Apresentadoras de Antígenos/citologia , Antígenos de Diferenciação/análise , Células da Medula Óssea/classificação , Células Progenitoras de Granulócitos e Macrófagos/citologia , Subunidade alfa1 de Receptor de Interleucina-13/análise , Mielopoese , Timo/citologia , Animais , Células Apresentadoras de Antígenos/química , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Células da Medula Óssea/química , Linhagem da Célula , Movimento Celular , Células Cultivadas , Feminino , Técnicas de Introdução de Genes , Células Progenitoras de Granulócitos e Macrófagos/química , Células Progenitoras de Granulócitos e Macrófagos/efeitos dos fármacos , Células Progenitoras de Granulócitos e Macrófagos/imunologia , Interleucina-13/farmacologia , Subunidade alfa1 de Receptor de Interleucina-13/deficiência , Subunidade alfa1 de Receptor de Interleucina-13/genética , Linfócitos Nulos/citologia , Linfopoese , Masculino , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Deleção de Sequência , Linfócitos T/citologia
16.
J Exp Med ; 205(10): 2269-80, 2008 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-18762566

RESUMO

Primary neonatal T cell responses comprise both T helper (Th) cell subsets, but Th1 cells express high levels of interleukin 13 receptor alpha1 (IL-13R alpha 1), which heterodimerizes with IL-4R alpha. During secondary antigen challenge, Th2-produced IL-4 triggers the apoptosis of Th1 cells via IL-4R alpha/IL-13R alpha 1, thus explaining the Th2 bias in neonates. We show that neonates acquire the ability to overcome the Th2 bias and generate Th1 responses starting 6 d after birth. This transition was caused by the developmental maturation of CD8 alpha(+)CD4(-) dendritic cells (DCs), which were minimal in number during the first few days of birth and produced low levels of IL-12. This lack of IL-12 sustained the expression of IL-13R alpha 1 on Th1 cells. By day 6 after birth, however, a significant number of CD8 alpha(+)CD4(-) DCs accumulated in the spleen and produced IL-12, which triggered the down-regulation of IL-13R alpha 1 expression on Th1 cells, thus protecting them against IL-4-driven apoptosis.


Assuntos
Animais Recém-Nascidos/imunologia , Células Dendríticas/imunologia , Imunidade/imunologia , Interleucina-12/biossíntese , Subpopulações de Linfócitos T/imunologia , Células Th2/imunologia , Transferência Adotiva , Animais , Apoptose/imunologia , Sobrevivência Celular , Células Dendríticas/citologia , Interferon gama/imunologia , Interleucina-12/imunologia , Subunidade alfa1 de Receptor de Interleucina-13/genética , Subunidade alfa1 de Receptor de Interleucina-13/imunologia , Interleucina-4/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Coelhos , Ratos , Baço/citologia , Baço/imunologia , Subpopulações de Linfócitos T/citologia , Células Th1/imunologia , Células Th2/citologia
17.
J Immunol ; 180(3): 1508-16, 2008 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18209046

RESUMO

A number of Ag-specific approaches have been developed that ameliorate experimental allergic encephalomyelitis (EAE), an animal model for the human autoimmune disease multiple sclerosis. Translation to humans, however, remains a consideration, justifying the search for more insight into the mechanism underlying restoration of self-tolerance. Ig-proteolipid protein (PLP) 1 and Ig-myelin oligodendrocyte glycoprotein (MOG) are Ig chimeras carrying the encephalitogenic PLP 139-151 and MOG 35-55 amino acid sequence, respectively. Ig-PLP1 ameliorates EAE in SJL/J (H-2(s)) mice while Ig-MOG modulates the disease in C57BL/6 (H-2(b)) animals. In this study, we asked whether the chimeras would suppress EAE in F(1) mice expressing both parental MHC alleles and representing a polymorphism with more relevance to human circumstances. The results show that Ig-MOG modulates both PLP1 and MOG peptide-induced EAE in the F(1) mice, whereas Ig-PLP1 counters PLP1 EAE but exacerbates MOG-induced disease. This in trans aggravation of MOG EAE by Ig-PLP1 operates through induction of PLP1-specific T cells producing IL-5 that sustained inhibition of MOG-specific Abs leading to exacerbation of EAE. Thus, in trans T cell tolerance, which should be operative in polymorphic systems, can aggravate rather than ameliorate autoimmunity. This phenomenon possibly takes place through interference with protective humoral immunity.


Assuntos
Autoanticorpos/imunologia , Quimera/imunologia , Encefalomielite Autoimune Experimental/imunologia , Tolerância Imunológica , Linfócitos T/imunologia , Animais , Quimera/genética , Encefalomielite Autoimune Experimental/genética , Epitopos/imunologia , Glicoproteínas/genética , Glicoproteínas/imunologia , Humanos , Imunoglobulinas/genética , Interleucina-5/metabolismo , Camundongos , Camundongos Mutantes , Proteínas da Mielina , Proteína Proteolipídica de Mielina/genética , Proteína Proteolipídica de Mielina/imunologia , Glicoproteína Associada a Mielina/genética , Glicoproteína Associada a Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito , Proteínas do Tecido Nervoso/imunologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Peptídeos/imunologia
18.
J Immunol ; 174(11): 6772-80, 2005 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15905518

RESUMO

To date, very few Ag-based regimens have been defined that could expand T regulatory (Treg) cells to reverse autoimmunity. Additional understanding of Treg function with respect to specificity and broad suppression should help overcome these limitations. Ig-proteolipid protein (PLP)1, an Ig carrying a PLP1 peptide corresponding to amino acid residues 139-151 of PLP, displayed potent tolerogenic functions and proved effective against experimental allergic encephalomyelitis (EAE). In this study, we took advantage of the Ig-PLP1 system and the PLP1-specific TCR transgenic 5B6 mouse to define a regimen that could expand Ag-specific Treg cells in vivo and tested for effectiveness against autoimmunity involving diverse T cell specificities. The findings indicate that in vivo exposure to aggregated Ig-PLP1 drives PLP1-specific 5B6 TCR transgenic cells to evolve as Treg cells expressing CD25, CTLA-4, and Foxp3 and producing IL-10. These Treg cells were able to suppress PLP1 peptide-induced EAE in both SJL/J and F(1) (SJL/J x C57BL/6) mice. However, despite being effective against disease induced with a CNS homogenate, the Treg cells were unable to counter EAE induced by a myelin basic protein or a myelin oligodendrocyte glycoprotein peptide. Nevertheless, activation with Ag before transfer into the host mice supports suppression of both myelin oligodendrocyte glycoprotein- and myelin basic protein peptide-induced EAE. Thus, it is suggested that activation of Treg cells by the cognate autoantigen is necessary for operation of broad suppressive functions.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/prevenção & controle , Ativação Linfocitária/imunologia , Proteína Proteolipídica de Mielina/imunologia , Fragmentos de Peptídeos/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Sequência de Aminoácidos , Animais , Efeito Espectador/genética , Efeito Espectador/imunologia , Proliferação de Células , Encefalomielite Autoimune Experimental/patologia , Epitopos de Linfócito T/administração & dosagem , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Dados de Sequência Molecular , Proteína Proteolipídica de Mielina/administração & dosagem , Proteína Proteolipídica de Mielina/genética , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Ratos , Receptores de Antígenos de Linfócitos T/genética , Recidiva , Índice de Gravidade de Doença , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/transplante
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...