Hypoxia pre-conditioned embryonic mesenchymal stem cell secretome reduces IL-10 production by peripheral blood mononuclear cells

Background: Mesenchymal stem cells [MSCs] are important candidates for MSC-based cellular therapy. Current paradigm states that MSCs support local progenitor cells in damaged tissue through paracrine signaling. Therefore, the study of paracrine effects and secretome of MSCs could lead to the appreciation of mechanisms and molecules associated with the therapeutic effects of these cells. This study analyzed anti-inflammatory and immune-modulatory effects of MSC secretomes derived from embryonic stem cells [ESCs] and bone marrow cells after hypoxia and normoxia preconditioning

Methods: ESCs differentiated into MSCs and characterized by flow cytometry as well as by differentiation into adipocytes and osteoblasts. The experimental groups were consisted of individual groups of ESC-MSCs and BM-MSCs [bone marrow-derived mesenchymal stromal cells], which were preconditioned with either hypoxia or normoxia for 24, 48 and 72 h. After collecting the cell-free medium from each treatment, secretomes were concentrated by centrifugal filters. Using a peripheral blood mononuclear cell [PBMC] assay and ELISA, IL-10 concentration in PBMCs was evaluated after their incubation with different secretomes from preconditioned and non-preconditioned MSCs

Results: A significant difference was observed between ESC-MSC normoxia and ESC-MSC hypoxia in IL-10 concentration, and normoxia secretomes increased IL-10 secretion from PBMCs. Moreover, the strongest IL-10 secretion from PBMCs could be detected after the stimulation by ESC-MSC conditioned secretomes, but not BM-MSC conditioned medium

Conclusions: Human hypoxia preconditioned ESC-MSC secretome indicated stronger immune-modulatory effects compared to BMMSC conditioned medium. It could be suggested that induced MSCs confer less immune-modulatory effects but produce more inflammatory molecules such as tumor necrosis factor alpha, which needs further investigation

Rapid flow cytometry based cytotoxicity assay for evaluation of NK cell function.

Assessment of natural killer cells (NK-cell) cytotoxicity is used not only in research settings but is also important in diagnosis of various diseases. NK-cell cytotoxicity assays are based on measurement of target cells killed by cytotoxic cells analyzed either by chromium (51Cr) release assay or flow cytometry. Both these methods use peripheral blood mononuclear cells (PBMC) or pure NK-cell population and hence require large volume of blood sample which is difficult to obtain in pediatric patients and patients with cytopenia. Hence, a flow cytometric assay was designed to determine NK cell activity using whole blood, eliminating the need for isolation of PBMCs or pure NK cells. This assay is based on a dual fluorescent staining of target cells (K562 cell line). The DIOC18 dye labeled K562 cells are incubated with whole blood and then counterstained with 7-AAD enabling the measurement of dead target cell and then percent cytotoxicity is calculated. This study compared the NK cell cytotoxicity using PBMC and whole blood in clinically relevant samples. There was no significant difference between two assays in the measurement of lytic activity or in reproducibility in the repeated samplings of healthy individuals. The whole blood assay required less volume of blood and also less processing time as compared to PBMC assay. It was also validated by testing patients diagnosed with familial hemophagocytic lymphohistiocytosis expected to have low NK-cell activity. This assay is rapid, sensitive and reproducible and requires significantly less volume of blood which is important for clinical evaluation of NK-cell function.

Vascular endothelial growth factor-A enhances indoleamine 2,3-dioxygenase expression by dendritic cells and subsequently impacts lymphocyte proliferation

Dendritic cells (DCs) are antigen (Ag)-presenting cells that activate and stimulate effective immune responses by T cells, but can also act as negative regulators of these responses and thus play important roles in immune regulation. Pro-angiogenic vascular endothelial growth factor (VEGF) has been shown to cause defective DC differentiation and maturation. Previous studies have demonstrated that the addition of VEGF to DC cultures renders these cells weak stimulators of Ag-specific T cells due to the inhibitory effects mediated by VEGF receptor 1 (VEGFR1) and/or VEGFR2 signalling. As the enzyme indoleamine 2,3-dioxygenase (IDO) is recognised as an important negative regulator of immune responses, this study aimed to investigate whether VEGF affects the expression of IDO by DCs and whether VEGF-matured DCs acquire a suppressor phenotype. Our results are the first to demonstrate that VEGF increases the expression and activity of IDO in DCs, which has a suppressive effect on Ag-specific and mitogen-stimulated lymphocyte proliferation. These mechanisms have broad implications for the study of immunological responses and tolerance under conditions as diverse as cancer, graft rejection and autoimmunity.

Viability of mesenchymal stem cells during electrospinning

Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10 percent polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6 percent and the viability of mononuclear cells from 99 to 8.38 percent. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage.

Effect of L-Arginine and L-NAME treatments on polymorphonuclear leukocytes and mononuclear cells influx during tumor growth / Efeito dos tratamentos com L-Arginina e L-NAME sobre o influxo de leucócitos polimorfonucleares e células mononucleares durante o desenvolvimento tumoral

PURPOSE: Evaluate polymorphonuclear leukocytes (PMN's) and mononuclear cells (MN's) involvement in the Ehrlich´s solid tumor (ET) growth. METHODS: 90 Swiss mice were inoculated with 10(7) tumor cells (sc), distributed in three groups and treated once a day, via intraperitoneal (ip), with 0.1ml of diluent, L-Arginine (20mg/Kg) or L-NAME (20mg/Kg). After 7, 15 and 30 days of treatment, ten animals of each group were euthanized, the tumor mass was removed, processed and fixed for HE. Later, a morphometric analysis of the total area, parenchyma, necrosis, tumor stroma and PMN's leukocytes and MN's cells influx was performed. RESULTS: The L-Arginine treatment increased PMN's influx in the initial stage, whereas L-NAME reduced it. Our data suggests that NO effect on PMN's migration is dose-dependent. On the other hand, the MN´s cells influx was reduced by L-NAME treatment at all evaluated periods and at the same periods an increase in tumor growth was observed. CONCLUSION: At initial stages of tumor implantation, both PMN's leukocytes and MN's cells act together to control ET development.

OBJETIVO: Avaliar o envolvimento de leucócitos polimorfonucleares (PMN's) e células mononucleares (MN's) no crescimento do Tumor Sólido de Ehrlich (TE). MÉTODOS: 90 camundongos Suíços foram inoculados com 10(7) células tumorais (sc), distribuídos em três grupos e tratados uma vez ao dia, via intraperitoneal (ip), com 0.1ml de diluente, L-Arginina (20mg/Kg) ou L-NAME (20mg/Kg). Após 7, 15 e 30 dias, dez animais de cada grupo foram eutanasiados, a massa tumoral foi removida, processada e corada pela HE. Posteriormente, foi realizada análise morfométrica das áreas total, parênquima, necrose, estroma e influxo de leucócitos PMN's e células MN's. RESULTADOS: O tratamento com L-Arginina favoreceu o influxo de PMN's em períodos iniciais, enquanto o tratamento com L-NAME o reduziu. Nosso estudo sugere que o efeito do ON sobre a migração de PMN's é dose-dependente. Por outro lado, o influxo de células MN´s foi contido pelo tratamento com L-NAME em todos os períodos avaliados, mesmos períodos em que se observou um aumento no crescimento tumoral. CONCLUSÃO: Em fases iniciais do implante tumoral, ambos, leucócitos PMN's e células MN's, atuam juntos no controle do desenvolvimento do TE.

Actividad supresora del millerenólido sobre células mononucleares de sangre periférica humana / Millerenolide induces suppressive activity on human peripheral blood mononuclear cells

Background: Natural products are used in the production of therapeutic drugs due to their wide diversity and excellent adaptability to biological structures. Sesquiterpene ¡aciones are the active constituents of several plants from the Asteraceae family. Aim: To assess the in vitro effect of a sesquiterpene lactone (millerenolide). Material and methods: The drug effect was assessed measuring the proliferation of lymphocytes using the 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonylJ-2H-tetrazolium hydroxide (XTT) technique. Changes on the cell cycle were analyzed on a FACSort flow cytometer The effect of millerenolide on the production of nitric oxide (NO) by macrophages was evaluated using the Griess reagent. Additionally, phagocytosis of latex particles and nitroblue tetrazolium (NBT) reduction by macrophages were evaluated microscopically. Results: Treatment of human peripheral blood mononuclear cells (PBMC) with millerenolide decreases the proliferation of lymphocytes, decreases the percentage of cells in S, and G2/Mphases, and increases the proportion of cells in GO/Gl phase. Treatment of macrophages with millerenolide, reduces the production of NO, the phagocytic capacity and the number of cells able to reduce NBT. Cytotoxic effects of the lactone on human PBMC were only observed when the concentration was increased to 6 fig/ml. Conclusions: Millerenolide could be considered as a potential therapeutic agent with immunosuppressiveproperties.

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation / Efecto inmunomodulatorio de los antibióticos sobre la secreción del factor de necrosis tumoral alfa por células sanguíneas mononucleares periféricas en respuesta a la estimulación de stenotrophomonas maltophilia

Some antibiotics have been shown to modify the host immune response. Infection with Stenotrophomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors examined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF alpha) production by human peripheral blood mononuclear cells (PBMC) stimulated with heat-killed S maltophilia. Cotrimoxazole was the only antibiotic that suppressed TNFa secretion at clinically achievable concentrations. This may explain its use with good effect in the treatment of S maltophilia infections. However at supratherapeutic concentrations, ceftazidime and ciprofloxacin, but not piperacillin-tazobactam, also inhibited significantly the production of TNF alpha. Cotrimoxazole, in addition to its antimicrobial effect against S maltophilia, has an immunomodulatory effect on peripheral blood mononuclear cells stimulated by S maltophilia.

Algunos antibióticos han mostrado ser capaces de modificar la respuesta inmune del huésped. Las infecciones con Stenotrophomonas maltophilia – un patógeno emergente – son difíciles de tratar debido a su multiresistencia a los antibióticos. Examinamos el efecto de cuatro agentes antimicrobianos comúnmente usados (ciprofloxacina, ceftazidima, cotrimoxazol, y piperacilina-tazobactam) sobre la producción del factor de necrosis tumoral alfa (FNTa) por las células sanguíneas mononucleares periféricas humanas (PBMC) estimuladas con S maltophilia inactivadas mediante calor. El cotrimoxazol – en concentraciones clínicamente posibles – fue el único antibiótico que eliminó la secreción FNTa. Esto puede explicar su uso efectivo en el tratamiento de las infecciones por S maltophilia. Sin embargo, en concentraciones supraterapéuticas, la ceftazidima y la cipro-floxacina – pero no la piperacilina-tazobactam – también inhibieron significativamente la producción de FNTa. El cotrimoxazol, además de su efecto antimicrobiano contra S maltophilia, tiene un efecto inmuno-modulatorio sobre las células sanguíneas mononucleares periféricas estimuladas por S maltophilia.

DNA-UMSAgen, extracción de DNA genómica para diagnóstico molecular: método rápido y económico / UMSAgen DNA, genomic DNA extraction for molecular diagnosis: rapid and economical method

Introducción. El estudio del ácido desoxirribunocleico (DNA) es imprescindible para la medicina moderna; por ello, se ha diseñado diferentes técnicas para su extracción, cuyos costos son altos y de tiempo prolongado. En este trabajo se describe un método modificado de extracción de DNA (DNA-UMSAgen) basado en la técnica de Miller. Métodos. Las células mononucleares fueron obtenidas de sangre venosa periférica de un sujeto voluntario, para realizar 40 extracciones de DNA; 20 con el método modificado DNA_UMSAgen y otros 20 con el método clásico. Posteriormente se evaluó la concentración, calidad y utilidad de estos DNA extraidos. Resultados. La pureza del DNA extraido por el método DNA-UMSAgen es de 1,88 similar al de la técnica clásica 1,91, las concentraciones obtenidas son 20,4 ug/106 cel y 56ug/106 cel respectivamente. La evaluación por electroforesis en agarosa y la amplificación del exon 12 del gen JAK2 por PCR fue satisfactoria. Conclusión. El método DNA-UMSAgen es una alternativa de extracción de DNA genómico, rápido y económico, adecuado para paises en vias de desarrollo.

INTRODUCTIONDNA is the genetic material of the cell. Actually for its study, laboratory techniques are available that require its extraction free of impurities. This paper describes the DNA-UMSAgen method as an alternative for DNA extraction which is based on the Miller technique.METHODSThe mononuclear cells were obtained of venous peripheral blood of a voluntary subject, for to realize 40 DNA's extractions; 20 with the modified method DNA-UMSAgen and other 20 with the classic method. Later there was evaluated the concentration, quality and utility of these extracted DNA.RESULTSThe DNA purity extracted by the DNA-UMSAgen method is 1,88 similar to the classic technique 1,91, the concentration obtained were 20,4 ug/106 cells and 56ug/106 cells respectively. The evaluation by agarose gel electrophoresis and the amplification of the exon 12 of the JAK2 gen by PCR was successful.CONCLUSIONThe DNA-UMSAgen extraction method is a very acceptable fast, easy and inexpensive alternative method for underdeveloped countries for DNA extraction.

Production and Expression of Gro-alpha and RANTES by Peripheral Blood Mononuclear Cells Isolated from Patients with Kawasaki Disease and Measles

We investigated whether the production and gene expression of Gro-alpha and RANTES in Kawasaki disease differ in measles. Forty-two samples from 14 patients in different clinical stages of Kawasaki disease, eight samples from 8 patients in the acute stage of measles and seven samples from 7 healthy children were collected. The present study was performed using ELISA and RT-PCR for the productions and gene expression of the chemokines. The production of Gro-alpha was markedly elevated during the acute stage of measles compared with Kawasaki disease. Moreover, the expression of Gro-alpha was increased in every case of measles, but not in Kawasaki disease. The production of RANTES was elevated in the acute stage of both diseases when compared to the healthy control. However, the plasma RANTES level did not change significantly according to the clinical stages of Kawasaki disease. A correlation between the production and gene expression of RANTES and Gro-alpha was not found in Kawasaki disease. These results suggest that Kawasaki disease differs from measles with regard to Gro-alpha production and expression, but not RANTES. Gro-alpha might play an important role in the acute stage of measles, however not in Kawasaki disease. Further studies are needed to clarify the efficacy of Gro-alpha as a marker in measles.

The relationship of host immune cells, cytokine and nitric oxide production to tumor cells in ovarian carcinoma

This brief review focuses on the current understanding of the complex relationship of tumor-associated mononuclear cells (TAMs) with neoplastic cells, summarizing their immunological efficiency, cytokine profile and production of nutric oxide (NO) in the tumor microenvironment, with current insights on how this might affect tumor growth. Data source: Data eas obtained through Medline from articles indexed during the last 10 years. The main key words used in the research were: cancer, ovarian cancer, cytokine, nitric oxide (NO), mononuclear cell, lymphocyte, macrophage. Selection of studies and data collection: 30 studies were reviewed, which contained data regarding the production of cytokines and NO by TAMs or malignant cells, and tried to establish a correlation between these mediators and tumor growth, especially in ovarian carcinoma. Data summary: TAMs consist mainly of macrophages and T lymphocytes which present lower proliferative indices and cytotoxicity compared to autologous blood monocytes, although they are able to release various cytokines. The profile of cytokine expression could help to explain both the immunological impairment observed in patients with advanced carcinoma diseases and the potential of TAMs to exert antitumor activity, which makes these cells an attractive target for therapeutic intervention. NO is also produced in the tumor microenvironment. Several reports in animals suggest a tumoricidad role for NO, but in human tumors its role has not been well-established and may change during tumor progression.

Interleukin-2 inducible cytotoxic activity of peripheral blood mononuclear cells from patients with type 2 diabetes mellitus

The ability of peripheral blood mononuclear cells [PBMNC] from 36 patients with type 2 diabetes and 26 healthy control subjects to acquire cytotoxic properties after in vitro incubation with interleukin-2 [IL-2] was examined. Cytotoxic activity of IL-2 activated PBMNC was measured by 51Cr-release assay from radiolabeled Burkitt lymphoma cells. The percentage of cytotoxicity of PBMNC from diabetic patients was not different from the control group when incubated with medium alone or with IL-2 at a concentration of 0.1 u/ml. Cytotoxic activity of IL-2 activated MNC was similar in all age groups in diabetic as well as controls. The kinetics of MNC activation by IL-2 were similar in the two groups with comparable degrees of activation in response to increasing concentrations of IL-2 and similar time course for activation reaching a maximum after 4-5 days of incubation and gradually decreased

Apoptosis: su papel en la ontogenia del sistema inmune y en la infeccion por HIV / Apoptosis: its role in the immune system ontogeny and in HIV infection

La apoptosis es un proceso que se caracteriza por la puesta en marcha de un programa letal genéticamente controlado que culmina en la muerte celular, con disminución del volumen, condensación de la cromatina y fragmentación del ADN nuclear. Es un mecanismo fisiológico por el cual se eliminan las células no deseadas o senescentes, sin causar inflamación. Interviene en la selección del repertorio de linfocitos en el timo, en el control de la proliferación celular y tumoral; además puede estar involucrado en el desarrollo de patología autoinmune o en la depleción linfocitaria que ocurre a consecuencia de infecciones virales, tales como el DISA. Se presenta una revisión de los mecanismos de apoptosis, especialmente dentro del sistema inmune, y de las técnicas más frecuentemente empleadas para su valoración

Mononuclear phagocytic system in acute pancreatitis

1. Functional alterations of the mononuclear phagocytic system (MPS) may be an important factor in the pathogenesis of infection in acute pancreatitis (AP). In the present study, MPS activity was investigated in rats and hepatic blood flow (HBF) was also determined. 2. A total of 122 male Wistar rats were divided into three groups: 1, AP group (N = 51); 2, sham-operated (SO) (N = 49); 3, intact group (IG) (N = 22). AP was induced by retrograde injection of 0.5 ml of 2.5 per cent sodium taurocholate saline into the main biliopancreatic duct under ketamine chloride anesthesia. SO animals were submitted to the same surgical steps as AP animals except for AP induction. 3. Each experimental group was subdivided into two subgroups. The first subgroup was submitted to the study of MPS activity as follows: each group was injected with colloidal 198Au and liver clearance parameters were determined 2 h (N = 11), 12 h (N = 10) and 24 h (N = 10) later in the AP group, and 2 h (N = 9), 12 h (N = 10) and 24 h (N = 11) later in the SO group. In the second subgroup, HBF was assessed using 131I-bromosulphalein at 2 h (N = 10) and 24 h (N = 10) in the AP group and at 2 h (N = 10) and 24 h (N = 10) in the SO group. The IG was submitted to both radioactive tracer studies. Each animal was used for only one experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Asma corticóideo resistente / Corticosteriod resistance in asthma

Desde hace años, los clínicos se han encontrado con pacientes asmáticos que no responden a corticoides. Estos comprenden pacientes con obstrucción irreversible de su vía aérea, pacientes con enfermedad severa que requieren altas dosis y un subgrupo menos frecuente, que se caracteriza por obstrucción bronquial reversible con ß2 agonistas, pero que no responden a corticoides, a dosis adecuadas. Diversos autores estudiaron la farmacocinética de los corticoides en estos pacientes, así como la presencia de anticuerpos antilipocortina, y los receptores esteróideos, no pudiendo aclarar el mecanismo de esta resistencia. La explicación a este fenómeno parece centrarse en la respuesta de los linfocitos, monocitos y eosinófilos de los pacientes a estas drogas, con disminución de efecto sobre varias funciones de las mismas, que nos acerca a la comprensión de la inflamación bronquial en asma

Cell mediated immunity in Chagas' disease. Trypanosoma cruzi antigens induce suppression of the in vitro proliferative response of mononuclear cells

The partial suppression of the cell-mediated immune response by Trypanosoma cruzi antigens in patients with Chagas' disease is demonstrated in a costimulation assay with T. cruzi antigens and Mycobacterium tuberculosis purified protein derivative (PPD) or Tetanus toxoid (TT). ononuclear cells from 13 patients with chagasic infection without evidence of heart disease, 10 patients with chagasic cardiomyopathy and 7 healthy blood donors were stimulated with antigen A (autoclaved epimastigotes), PPD, TT, PPD + A, PPD + TT and TT + A. The average percentage of suppression induced by costimulation of mononuclear cells with PPD and antigen A was 47.1% in patients with chagasic infection without heart disease (INF), 38.8% in patients with chagasic cardiomyopathy (CDM) and 23.3% in healthy controls. Similar values were observed when living trypomastigotes were used. A costimulatory study with PPD and TT, PPD and A and TT and A was carried out in 8 patients with chagasic infection, in order to evaluate the possibility that this difference could be due to a nonspecific inhibitory effect. The mean suppression induced by TT + PPD was -8.9, with TT + A was 52.7 and with PPD + A was 50.1. The data reported show that T. cruzi antigens induce a specific suppression of the proliferative responseof mononuclear cells, that might be relevant to the persistence of the parasite in the host

An alternative method for in vitro production of HIV-1-specific antibodies

We describe the detection of HIV-1-specific antibody secretion by a 24-h culture of peripheral blood mononuclear cells (PBMC) stimulated with disrupted inactivated whole virus absorved onto commercial ELISA microwell plates. The method showed high sensitivity and specificity and was capable of accurately detecting HIV-1 infection early after birth (9 of the 19 patients were < 3 years old) because maternal antibodies do not iterfere by giving false-postive results. No false-positive results were obtained with PBMC from 24 HIV-1-seronegative asymptomatic individuals and no false-negative results were obteined for 10 seropostive adult patients (16-46 years pf age). This rapid, relatively low cost, simple, highly sensitive and specific assay can be extremely useful for the early diagnosis of pediatric AIDS cases

Resposta fagocitária e atividade quimiotática de leucócitos mononucleares em crianças eutróficas / Phagocytic response and chemotaxic activity of mononuclear leukocytes in eutrophic children

A funçäo fagocitária e a atividade quimiotática de leucócitos mononucleares foram avaliadas em cinqüenta crianças eutróficas na faixa etária de dois a dez anos, com o objetivo de estabelecer curvas padröes

Correlation between the lack of mononuclear cell cytotoxicity against schistosomula in vitro with schistosomiasis

A comparison was made of the reactivity of mononuclear cells from subjects and from S. mansoni-infected patients. The following parameters were evaluated: 1) ability of mononuclear cells to kill schistosoma in the presence of complement; 2) [3H]-inositol incorporation into phosphatidylinositol (PI) and the rate of inositolphosphates (IPx) released. Cells from normal subjects, but not from S. mansoni infected patients, were able to kill schistosomula in vitro. A decrease in inositolpolyphosphates (IPx) was observed for phytohemagglutinin (PHA)-stimulated mononuclear cells from infected patients when compared with mononuclear cells from normal subjects after 24 h of incubation. The results suggest that the reactivity of mononuclear cells from infected patients is altered under conditions of nonspecific stimulation with PHA when compared with normal cells