Expansion of CD4(+) CD25(+) Foxp3(+) T cells by bone marrow-derived dendritic cells

Dendritic cells (DCs) are the most important antigen-presenting cells of the immune system and have a crucial role in T-lymphocyte activation and adaptive immunity initiation. However, DCs have also been implicated in maintaining immunological tolerance. In this study, we evaluated changes in the CD4(+) CD25(+) Foxp3(+) T-cell population after co-culture of lymph node cells from BALB/c mice with syngeneic bone marrow-derived DCs. Our results showed an increase in CD4(+) CD25(+) Foxp3(+) T cells after co-culture which occurred regardless of the activation state of DCs and the presence of allogeneic apoptotic cells; however, it was greater when DCs were immature and were pulsed with the alloantigen. Interestingly, syngeneic apoptotic thymocytes were not as efficient as allogeneic apoptotic cells in expanding the CD4(+) CD25(+) Foxp3(+) T-cell population. In all experimental settings, DCs produced high amounts of transforming growth factor (TGF)-beta. The presence of allogeneic apoptotic cells induced interleukin (IL)-2 production in immature and mature DC cultures. This cytokine was also detected in the supernatants under all experimental conditions and enhanced when immature DCs were pulsed with the alloantigen. CD4(+) CD25(+) Foxp3(+) T-cell expansion during co-culture of lymph node cells with DCs strongly suggested that the presence of alloantigen enhanced the number of regulatory T cells (Tregs) in vitro. Our data also suggest a role for both TGF-beta and IL-2 in the augmentation of the CD4(+) CD25(+) Foxp3(+) population.

Autologous bone marrow transplantation in a dog with lymphoma: a clinical study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Membrane-bound alkaline phosphatase from ectopic mineralization and rat bone marrow cell culture

Cells from rat bone marrow exhibit the proliferation-differentiation sequence of osteoblasts, form mineralized extracellular matrix in vitro and release alkaline phosphatase into the medium. Membrane-bound alkaline phosphatase was obtained by method that is easy to reproduce, simpler and fast when compared with the method used to obtain the enzyme from rat osseous plate. The membrane-bound alkaline phosphatase from cultures of rat bone marrow cells has a MWr of about 120 kDa and specific PNPP activity of 1200 U/tng. The ecto-enzyme is anchored to the plasma membrane by the GPI anchor and can be released by PIPLC (selective treatment) or polidocanol (0.2 mg/mL protein and 1% (w/v) detergent). The apparent optimum pH for PNPP hydrolysis by the enzyme was pH 10. This fraction hydrolyzes ATP (240 U/mg), ADP (350 U/ mg), glucose 1-phosphate (1100 U/mg), glucose 6-phosphate (340 Wing), fructose 6-phosphate (460 U/mg), pyrophosphate (330 U/mg) and (3glycerophosphate (600 U/mg). Cooperative effects were observed for the hydrolysis of PPi and beta-glycerophosphate. PNPPase activity was inhibited by 0.1 mM vanadate (46%), 0.1 mM ZnCl2 (68%), 1 mM levamisole (66%), 1 mM arsenate (44%), 10 mM phosphate (21%) and 1 mM theophylline (72%). We report the biochemical characterization of membrane-bound alkaline phosphatase obtained from rat bone marrow cells cultures, using a method that is simple, rapid and easy to reproduce. Its properties are compared with those of rat osseous plate enzyme and revealed that the alkaline phosphatase obtained has some kinetics and structural behaviors with higher levels of enzymatic activity, facilitating the comprehension of the mineralization process and its function. (c) 2006 Elsevier B.V. All rights reserved.

Absence of mutagenicity effects of Psidium cattleyanum Sabine (Myrtaceae) extract on peripheral blood and bone marrow cells of mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Graft versus host disease in a rat small bowel transplant model after T-cell depleted donor specific bone marrow infusion

Baixas doses de irradiação associadas à infusão de células da medula óssea não previnem a ocorrência da reação do enxerto versus hospedeiro após o transplante intestinal. OBJETIVO: Neste estudo foi avaliado a potencial vantagem em estender o regime imunossupressor associado a infusão de células de medula óssea do doador depletadas de células T na prevenção da reação do enxerto versus hospedeiro após o transplante intestinal. MÉTODOS: Transplante heterotópico de intestino delgado foi realizado em ratos Lewis como receptores e da como doadores, distribuídos em cinco grupos de acordo com a duração da imunossupressão, irradiação e do uso de medula óssea normal ou depletada: G1 (n=6), sem irradiação e G2 (n=9), G3 (n=4), G4 (n=5) e G5 (n=6) foram irradiados com 250 rd. Grupos1, 2, 4 e G3 e 5 foram infundidos com 100 x 10(6) células da medula normal e depletada respectivamente. Animais no G1,2,3 foram imunossuprimidos com 1mg/kg/FK506/ IM por cinco dias e G4 e cinco por 15 dias. Anticorpos monoclonais contra células CD3 e colunas magnéticas foram utilizadas para a depleção da medula óssea. Os animais foram examinados para a presença de rejeição, reação do enxerto versus hospedeiro, chimerismo e biópsias intestinais e da pele. RESULTADOS: Rejeição mínima foi observada em todos os grupos; entretanto, a reação do enxerto versus hospedeiro somente nos animais irradiados. Extensão da imunossupressão alterou a gravidade da reação nos animais dos G4 e 5. Rejeição foi a causa mortis no G1 e a reação do enxerto versus hospedeiro nos Grupos 2,3,4 e 5, não controlada com a infusão de medula óssea depletada. O chimerismo total e de células T do doador foi estatisticamente maior nos grupos irradiados em comparação ao G1. CONCLUSÃO: A extensão do regime de imunossupressão associado a baixas doses de irradiação diminui a gravidade da reação do enxerto versus hospedeiro, não abolida pelo uso de medula óssea depletada.

Chimerism induction by nonmyeloablactive preconditioning and bone marrow infusion in rat small bowel transplantation

Em estudo recente demonstramos que a infusão de células da medula óssea do doador após o transplante intestinal não aumentou a sobrevida do enxerto quando se utilizou series curtas de drogas imunossupressoras. OBJETIVO: Neste estudo avaliamos se a utilização de diferentes regimes de irradiação em associação com a infusão de medula óssea altera a sobrevida do enxerto e a morbidade sobre receptor. MÉTODOS: Realizou-se o transplante heterotópico de intestino delgado, utilizando-se ratos Lewis como receptores e da como doadores, imunossuprimidos com FK 506 na dose de 1mg/kg/dia por 5 dias e distribuídos em 4 grupos: G1 (n= 4), não irradiado e sem infusão de medula óssea; G2 (n= 6), G3 (n= 9) e G4 (n= 6) foram infundidos com 100 x 10(6) células de medula após o transplante. Grupos 3 e 4 foram irradiados com 250 e 400 rd respectivamente. Os animais foram examinados diariamente para a detecção de rejeição e reação do enxerto versus hospedeiro, tendo sido colhidas amostras semanais de sangue para estudos de quimerismose biopsias quinzenais da estomia. RESULTADOS: Animais nos G1 e G2 apresentaram rejeição mínima no 15º pós-operatório, enquanto a reação do enxerto versus hospedeiro foi caracterizada nos G3 e G4. Os níveis de quimerismo total e de células T foram maiores nos grupos irradiados em comparação aos não irradiados. A causa mortis nos G1 e G2 foi a rejeição enquanto que nos G3 e G4 foi a reação do enxerto versus hospedeiro. CONCLUSÃO: Concluímos que a utilização de baixas doses de irradiações retardam o aparecimento da rejeição, mas não previne a ocorrência da reação do enxerto versus hospedeiro.

Bone marrow necrosis related to paracoccidioidomycosis: the first eight cases identified at autopsy

To report the first eight bone marrow necrosis (BMN) cases related to paracoccidioidomycosis (PCM) from patient autopsies with well-documented bone marrow (BM) histology and cytology.A retrospective evaluation was performed on BM specimens from eight autopsied patients from Botucatu University Hospital with PCM-related BMN. Relevant BMN literature was searched and analysed.All eight patients had acute PCM. Six had histological only (biopsies) and two cytological only (smears) specimens. Five biopsy specimens revealed severe and one mild coagulation patterned necrotic areas. Five had osteonecrosis. The cytological specimens also showed typical BMN patterns. Paracoccidioides brasiliensis yeast forms were visible within necrotic areas in all cases.

Autologous implant of bone marrow mononuclear cells as treatment of induced equine tendinitis

Superficial digital flexor tendonitis is an important cause of lameness in horses and its incidence ranges from 13% to 30%, depending on the horse's activity. This injury can occur in yearlings and compromise its carriers by reinjury or even impossibility to return to athletic life. In spite of the long period required for tendon repair, the scar tissue presents lack of elasticity and stiffness. As current treatment strategies produce only marginal results, there has been great interest in research of therapies that influence the quality or the speed of tendon repair. Stem cell therapy has shown promising results in degenerative diseases and cases of deficient healing processes. This study aims to evaluate the influence of autologous mesenchymal bone marrow stem cells in tendon healing, comparing treated and non-treated tendons. Superficial digital flexor tendonitis lesions were induced by collagenase infiltration in both forelimbs of 6 horses, followed by autologous implant in one of the forelimbs of each animal. The horses were evaluated using clinical, ultrasonographic, histopathologic, and immunohistochemical parameters. Tendon biopsies were performed at Day 48. Results found in the treatment group, such as high inflammatory cells infiltration, extracellular matrix synthesis, reduced amount of necrosis areas, small increase in cellular proliferation (KI-67/MIB-1), and low immunoreactivity to transforming growth factor P I, suggested the acceleration of tendon repair in this group. Further studies should be conducted in order to verify the influence of this treatment on later phases of tendon repair. Overall, after analysis of the results, we can conclude that cellular therapy with the mononuclear fraction of bone marrow has accelerated tendon repair at 48 days after treatment.

Evaluation of castor oil-based polyurethane membranes in rat bone-marrow cell culture

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of thrombopoietic activity through the quantification of megakaryocytes in bone marrow cytology and reticulated platelets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Centrifuged Bone Marrow on Bone Regeneration Around Implants in Rabbit Tibia

Objective: To evaluate the bone regeneration of cervical defects produced around titanium implants filled with blood clot and filled with centrifuged bone marrow (CBM) by means of histomorphometric analysis.Materials and Methods: Twelve rabbits received 2 titanium implants in each right tibia, with the upper cortical prepared with a 5-mm drill and the lower cortex with a 3-mm-diameter drill. Euthanasia was performed to allow analysis at 7, 21, and 60 days after operation. The samples were embedded in light curing resin, cut and stained with alizarin red and Stevenel blue for a histomorphometric analysis of the bone-to-implant contact (BIC) and the bone area around implant (BA). The values obtained were statistically analyzed using the nonparametric Kruskal-Wallis test (P = 0.05).Results: At 60 days postoperation, the groups had their cervical defects completely filled by neo-formed bone tissue. There was no statistically significant difference between the groups regarding BIC and BA during the analyzed periods.Conclusion: There was no difference in the bone repair of periimplant cervical defects with or without the use of CBM. (Implant Dent 2012;21:481-485)

MKK3/6-p38 MAPK signaling is required for IL-1 beta and TNF-alpha-induced RANKL expression in bone marrow stromal cells

Coupled bone turnover is directed by the expression of receptor-activated NF-kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG). Proinflammatory cytokines, such as interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) induce RANKL expression in bone marrow stromal cells. Here, we report that IL-1 beta and TNF-alpha-induced RANKL requires p38 mitogen-activating protein kinase (MAPK) pathway activation for maximal expression. Real-time PCR was used to assess the p38 contribution toward IL-1 beta and TNF-alpha-induced RANKL mRNA expression. Steady-state RANKL RNA levels were increased approximately 17-fold by IL-1 beta treatment and subsequently reduced similar to 70%-90% when p38 MAPK was inhibited with SB203580. RANKL mRNA stability data indicated that p38 MAPK did not alter the rate of mRNA decay in IL-1 beta-induced cells. Using a RANKL-luciferase cell line receptor containing a 120-kB segment of the 5' flanking region of the RANKL gene, reporter expression was stimulated 4-5-fold by IL-1 beta or TNF-alpha treatment. IL-1 beta-induced RANKL reporter expression was completely blocked with specific p38 inhibitors as well as dominant negative mutant constructs of MAPK kinase-3 and -6. In addition, blocking p38 signaling in bone marrow stromal cells partially inhibited IL-1 beta and TNF-alpha-induced osteoclastogenesis in vitro. Results from these studies indicate that p38 MAPK is a major signaling pathway involved in IL-1 beta and TNF-alpha-induced RANKL expression in bone marrow stromal cells.

Microscopic Evidences That Bone Marrow Mononuclear Cell Treatment Improves Sciatic Nerve Regeneration After Neurorrhaphy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Detection of Ehrlichia canis in bone marrow aspirates of experimentally infected dogs

O presente trabalho descreve a detecção de células infectadas em aspirados de medula óssea de cães experimentalmente infectados com uma amostra brasileira de Ehrlichia canis. Os cães foram monitorados duas vezes por dia através de avaliação clínica e exames de esfregaços de sangue periférico. A cada três dias, amostras de sangue foram coletadas para contagem celular. Semanalmente foram feitas punções de medula óssea para exame microscópico direto do material aspirado e coleta de sangue para exames sorológicos através da reação de imunofluorescência indireta. Os sinais clínicos observados foram febre, membranas pálidas, linfadenopatias, secreções nasais serosas e acentuada perda de peso. As alterações hematológicas incluíram anemia normocítica normocrômica, redução de neutrófilos e linfócitos e trombocitopenia. Poucas células infectadas com E. canis foram observadas em esfregaços sanguíneos, entretanto várias formas de desenvolvimento de E. canis foram visualizadas em aspirados de medula óssea 15 dias após a infecção.