Leishmania infantum induces high phagocytic capacity and intracellular nitric oxide production by human proinflammatory monocyte

BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.

Intracellular reactive oxygen species production and phagocytosis of Staphylococcus aureus by milk neutrophils as tool to diagnose mastitis and identify susceptible dairy cows / Produção intracelular de espécies reativas de oxigênio e fagocitose de Staphylococcus aureus por neutrófilos lácteos como ferramentas para o diagnóstico da mastite e identificação de vacas leiteiras susceptíveis à mastite

The immune response capacity of the mammary gland plays a major role to determine if mastitis will or not be established. Thus, we hypothesize that a better understanding of polymorphonuclear neutrophil leukocyte (PMN) function will elucidate mechanisms that will improve our knowledge of how we could avoid an inflammatory process by increasing the immune capacity of the cow, and even further, to search for a tool to diagnose mastitis or a possible way to select and identify non-susceptible animals. The present study utilized 112 quarters from 28 Holstein dairy cows that were divided into quarters milk samples with somatic cell count (SCC) <2×105 cells mL-1 (n=72) and SCC >2×105 cells mL-1 (n=40). The percentages of milk PMNs and the levels of intracellular reactive oxygen species (ROS) and the phagocytosis of Staphylococcus aureus by milk neutrophils were evaluated by flow cytometry. Our results showed a higher percentage of neutrophils in quarter milk samples with high SCC (P=0.0003), and this group also had a significantly higher percentage of neutrophils that produced ROS (P=0.008). On the other hand, the phagocytosis intensity of S. aureus by milk neutrophils was higher in quarters with low SCC (P=0.003), suggesting a better mammary gland immunity against invading pathogens. Analyzing the results of the predictive values of the measured PMN functions, they cannot be used isolated as a good diagnosis test since none of them had a satisfactory sensitivity and specificity values, which was also confirmed by the Youden index values being far from one. In conclusion, the assessment of milk bovine neutrophil functions could improve our understanding of the cellular basis of mastitis. Although, the intracellular ROS production and S. aureus phagocytosis by milk neutrophil did not have high predictive values to detect intramammary infections, our results strengthen the idea that that poor bovine mammary gland neutrophil phagocytic ability may be associated with high SCC, and might be considered to identify susceptible dairy cows to mastitis.(AU)

A resposta imune da glândula mamária desempenha um papel importante ao determinar o estabelecimento da infecção. Desta forma, a melhor compreensão da função dos neutrófilos irá nos subsidiar conhecimentos, pelo qual podemos evitar o processo inflamatório pela otimização da resposta imune de bovinos leiteiros, e fornece ferramentas para diagnosticar a mastite ou um possível instrumento para identificar e selecionar animais resistentes à infecção intramamária, aumentando a produtividade do rebanho. O presente estudo utilizou 112 amostras provenientes de quartos mamários de 28 vacas Holandesas que foram divididos em amostras de leite com baixa (n=72; <2×105 células mL-1) ou alta (n=40; 2×105 células mL-1) contagem de células somáticas (CCS). A porcentagem de neutrófilos no leite, a produção intracelular de espécies reativas de oxigênio (ERO) e a fagocitose de Staphylococcus aureus pelos neutrófilos do leite foram avaliadas por citometria de fluxo. Os resultados do presente estudo demonstraram maior percentagem de neutrófilos (CH138+; P=0,0003) e percentagem de neutrófilos que produziram ERO (P=0,008) em amostras de leite com alta CCS. Por outro lado, a intensidade de fagocitose de S. aureus por neutrófilos em amostras de leite com baixa CCS (P=0,003), que demonstra maior atividade funcional destas células neste grupo. As funções neutrofílicas para o diagnóstico da mastite não apresentaram valores de sensibilidade e especificidade altos, que foram confirmados pelo índice Youden. Desta forma, conclui-se que a produção intracelular de ERO e fagocitose de S. aureus pelos neutrófilos do leite não apresentaram valores preditivos altos para detecção de mastite. Além disto, os resultados do presente estudo reforçam a ideia de neutrófilos do leite com menor capacidade fagocítica podem ser associados à alta CCS, e pode ser considerado como uma ferramenta para identificar animais mais susceptíveis à infecções intramamárias.(AU)

Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.

Phenotypic and Functional Analysis of HL-60 Cells Used in Opsonophagocytic-Killing Assay for Streptococcus pneumoniae

Differentiated HL-60 is an effector cell widely used for the opsonophagocytic-killing assay (OPKA) to measure efficacy of pneumococcal vaccines. We investigated the correlation between phenotypic expression of immunoreceptors and phagocytic ability of HL-60 cells differentiated with N,N-dimethylformamide (DMF), all-trans retinoic acid (ATRA), or 1alpha, 25-dihydroxyvitamin D3 (VitD3) for 5 days. Phenotypic change was examined by flow cytometry with specific antibodies to CD11c, CD14, CD18, CD32, and CD64. Apoptosis was determined by flow cytometry using 7-aminoactinomycin D. Function was evaluated by a standard OPKA against serotype 19F and chemiluminescence-based respiratory burst assay. The expression of CD11c and CD14 gradually increased upon exposure to all three agents, while CD14 expression increased abruptly after VitD3. The expression of CD18, CD32, and CD64 increased during differentiation with all three agents. Apoptosis remained less than 10% until day 3 but increased after differentiation by DMF or ATRA. Differentiation with ATRA or VitD3 increased the respiratory burst after day 4. DMF differentiation showed a high OPKA titer at day 1 which sustained thereafter while ATRA or VitD3-differentiated cells gradually increased. Pearson analysis between the phenotypic changes and OPKA titers suggests that CD11c might be a useful differentiation marker for HL-60 cells for use in pneumococcal OPKA.

Comparative immunomodulation potential of Tinospora cordifolia (Willd.) Miers ex Hook. F., Tinospora sinensis (Lour.) Merrill and Tinospora cordifolia growing on Azadirachta indica A. Juss.

Guduchi has been widely used in the traditional medicine as an immunomodulator. Description of guduchi in Ayurvedic literature resemble with T. sinensis rather than with commonly available T. cordifolia and hence this may be used as substitutes for T. sinensis. T. cordifolia growing on Azadirachta indica commonly called Neem-guduchi has more immunomodulatory potential. Thus, immunomodulatory activity of three Tinospora spp. was assessed by checking humoral and cell mediated immune responses to the antigenic challenges with sheep RBCs and by neutrophil adhesion tests on albino Wistar rats using Guduchi-Satwa, a well known dosage form. Results revealed that Neem-guduchi possesses higher immunomodulatory potential at the dose of 300 mg/kg, po and validated the traditional claim. Hence, Neem-Guduchi can be employed in immunomodulatory formulation prepared using guduchi.

Fagocitose intensificada de Corynebacterium pseudotuberculosis por células da série monócito-macrófago de caprinos naturalmente infectados pelo vírus da artrite encefalite / Enhanced phagocytosis of Corynebacterium pseudotuberculosis by monocyte-macrophage cells from goats naturally infected with caprine arthritis encephalitis vírus

A Artrite Encefalite Caprina (AEC) e a Linfadenite Caseosa (LC) possuem alta incidência e transmissibilidade em pequenos ruminantes. Como ambas possuem tropismo por monócitos-macrófagos e afetam mecanismos da resposta inata do hospedeiro, acredita-se que a AEC predispõe o animal a infecções por Corynebacteruim pseudotuberculosis, agente etiológico da LC. Para confirmar esta hipótese, avaliou-se a fagocitose de células da série monócito-macrófago de cabras naturalmente infectadas pelo vírus da AEC (VAEC). Para tanto, foram utilizadas 30 cabras da raça Saanen, alocadas em dois grupos distintos, com 15 animais cada, conforme a sororreatividade de anticorpos séricos antivírus da AEC. Células mononucleares de sangue periférico foram isoladas por gradiente de densidade e plaqueadas para isolamento de células da série monócito-macrófago. Posteriormente, o ensaio de fagocitose de C. pseudotuberculosis foi realizado, após incubação por duas horas a 37ºC a 5% de CO2, e a visualização da fagocitose foi identificada por microscopia óptica. O presente estudo não encontrou diferença na porcentagem de monócito-macrófagos que realizaram fagocitose entre os diferentes grupos (P = 0,41). Todavia, a análise quantitativa de bactérias fagocitadas, demonstrou maior capacidade fagocítica pelos macrófagos-monócitos do grupo sororreagente ao vírus da AEC. Correlação entre monócitos fagocitando e macrófagos que fagocitaram mais de 12 bactérias foi observado neste grupo (r = 0,488; P = 0,006), não sendo o mesmo encontrado no grupo de animais sorroreagentes negativos. Os dados demonstram aumento na intensidade da fagocitose de macrófagos de animais infectados com o vírus da AEC.

Caprine arthritis encephalitis (CAE) and caseous lymphadenitis (CL) have high incidence and transmissibility in small ruminants. Since both virus have tropism for macrophages and monocytes and affect the innate immune response, it is believed that CAE can predispose the animal to infection by Corynebacteruim pseudotuberculosis, the etiological agent of CL. To confirm this hypothesis, we evaluated phagocytosis from the monocyte-macrophage cells from 30 Saanen goats. Goats were uniformly divided in two groups according to results of agar gel immunodiffusion test for CAE virus (CAEV). Peripheral blood mononuclear cells were isolated by density gradient centrifugation and the monocyte-macrophage cells were isolated from the mononuclear cells by their adhesion properties in plaques. Afterwards, phagocytosis of C. psudotuberculosis was performed for two hours at 37ºC, 5% of CO2, and assessed by microscopic visualization. There was no difference in the percentage of monocyte-macrophage cells that phagocytozed C. bovis between groups (P=0.41). However, when phagocytosis rates were classified according to the number of C. pseudotuberculosis phagocyted, the percentage of monocyte-macrophage cells that internalized more than 12 bacteria were higher in serologically CAEV positive animals compared to the serologically negative ones (P<0.001). Furthermore, a positive and significant correlation (r = 0.488; P = 0.006) between the percentage of monocyte-macrophage cells that internalized more than 12 bacteria and the percentage of monocyte that were carrying out phagocytosis was also encountered in serologically CAEV positive goats, however the same were not observed in serologically negative ones. These results demonstrated an alteration in the intensity of C. pseudotuberculosis phagocytosis by monocytes-macrophages from goats infected by CAEV. Thus, these results indicated that goats infected with CAEV may be more susceptible to CL.

Efecto inmunomodulador de la ozonoterapia en niños con deficiencia en la inmunidad mediada por fagocitos / Immunomodulator effect of ozone therapy in children with deficiency in immunity mediated by phagocytes

Se realizó un estudio pre-experimental antes después, con la finalidad de evaluar el efecto inmunomodulador de la ozonoterapia en niños con inmunodeficiencia por defectos en la inmunidad mediada por fagocitos. El universo estuvo constituido por un total de 18 niños con deficiencias en la fagocitosis, asistidos en la consulta de Inmunología en el periodo desde septiembre de 2009 hasta junio de 2010, que cumplieron con los criterios de inclusión y exclusión. El ozono se aplicó en dosis escalonadas por insuflación rectal hasta una concentración de 40µg/mL, durante tres meses. Las variables fueron evaluadas 1 mes después del tratamiento. Se determinó si existen diferencias significativas entre las determinaciones antes y después de la ozonoterapia, mediante la prueba T de comparación de medias para muestras dependientes, con un nivel de significación α=0.05. Hubo aumentos significativos del conteo absoluto de neutrófilos en el 100 por ciento de los casos y en el 94 por ciento mejoró significativamente la función fagocítica leucocitaria después de recibir la ozonoterapia. El estado clínico, cualitativamente evaluado, fue satisfactorio en los niños tratados con Ozono y no se reportaron reacciones adversas durante el tratamiento. Se sugiere este proceder terapéutico como alternativa terapéutica inmunoestimulante en la deficiencia fagocítica.

A pre-experimental study was conducted before then, in order to assess the effect of immunomodulator of ozone therapy in children with immunodeficiency defects of phagocyte-mediated immunity. The universe was made up by a total of 18 children with deficiencies in phagocytosis, assisted in the Immunology consultation from September 2009 until June 2010 that met the inclusion and exclusion criteria. Ozone was applied in doses by rectal insufflation stepped up a 40µg/mL concentration, for three months. The variables were assessed 1 month after treatment. It was determined if there are significant differences between determinations before and after of ozone therapy, through T of means comparison test for dependent samples, with a significance level α = 0. 05. There were significant increases in the absolute neutrophil count in 100 percent of cases and the Leukocyte Phagocytic function significantly improved in a 94 percent after receiving ozone therapy. The clinical state, qualitatively evaluated, was satisfactory in children treated with ozone and no adverse reactions were reported during treatment. It is suggested this therapeutic approach as immunostimulant therapeutic alternative in the phagocytic deficiency.

The effect of conglutinin on production of reactive oxygen species in bovine granulocytes

Conglutinin is a high molecular-weight lectin originally detected in bovine serum. It belongs to the family of collectins that bind sugar residues in a Ca(2+)-dependent manner and are effector molecules in innate immunity. Conglutinin appears to play an important role in immune defense mechanisms, showing antiviral and antibacterial activities when tested in vivo and in vitro. The present study evaluated the effect of conglutinin on the respiratory bursts in bovine peripheral phagocytes. Using nitroblue tetrazolium and hydrogen peroxide assays, we showed that sugar ligand-bound conglutinin stimulated the production of superoxide and H2O2 in granulocytes whereas the non-sugar-bound form of conglutinin inhibited these processes. These results indicate that both forms of conglutinin are able to interact with surface leukocyte receptors but have opposite effects on phagocytic activity. Our findings suggest that conglutinin bound to sugar residues on microbial surfaces can induce oxygen burst in phagocytes, and thereby mediates the elimination of pathogens and prevents the spread of infection.

Human monocytes tolerant to LPS retain the ability to phagocytose bacteria and generate reactive oxygen species

Tolerance to lipopolysaccharide (LPS) occurs when animals or cells exposed to LPS become hyporesponsive to a subsequent challenge with LPS. This mechanism is believed to be involved in the down-regulation of cellular responses observed in septic patients. The aim of this investigation was to evaluate LPS-induced monocyte tolerance of healthy volunteers using whole blood. The detection of intracellular IL-6, bacterial phagocytosis and reactive oxygen species (ROS) was determined by flow cytometry, using anti-IL-6-PE, heat-killed Staphylococcus aureus stained with propidium iodide and 2',7'-dichlorofluorescein diacetate, respectively. Monocytes were gated in whole blood by combining FSC and SSC parameters and CD14-positive staining. The exposure to increasing LPS concentrations resulted in lower intracellular concentration of IL-6 in monocytes after challenge. A similar effect was observed with challenge with MALP-2 (a Toll-like receptor (TLR)2/6 agonist) and killed Pseudomonas aeruginosa and S. aureus, but not with flagellin (a TLR5 agonist). LPS conditioning with 15 ng/mL resulted in a 40 percent reduction of IL-6 in monocytes. In contrast, phagocytosis of P. aeruginosa and S. aureus and induced ROS generation were preserved or increased in tolerant cells. The phenomenon of tolerance involves a complex regulation in which the production of IL-6 was diminished, whereas the bacterial phagocytosis and production of ROS was preserved. Decreased production of proinflammatory cytokines and preserved or increased production of ROS may be an adaptation to control the deleterious effects of inflammation while preserving antimicrobial activity.

The importance of apoptosis for immune regulation in Chagas disease

Host cell apoptosis plays an important immune regulatory role in parasitic infections. Infection of mice with Trypanosoma cruzi, the causative agent of Chagas disease, induces lymphocyte apoptosis. In addition, phagocytosis of apoptotic cells stimulates the growth of T. cruzi inside host macrophages. In spite of progress made in this area, the importance of apoptosis in the pathogenesis of Chagas disease remains unclear. Here we review the evidence of apoptosis in mice and humans infected with T. cruzi. We also discuss the mechanisms by which apoptosis can influence underlying host responses and tissue damage during Chagas disease progression.

Ação dos leucotrienos na fagocitose via receptores Fc`GAMA´ e manose em macrófagos alveolares e mecanismos moleculares envolvidos / Importance of leukotrienes en phagocytosis of Fc`GAMA´ and mannose receptor in alveolar macrophages and molecular mecanismes involved

Os leucotrienos aumentam a fagocitose e a atividade microbicida contra uma série de patógenos. Em macrófagos alveolares, LTB`IND.4´ e LTD`IND.4´ aumentam a fagocitose via Fc`GAMA´R de modo dependente de PKC. Entretanto, o papel das isoformas específicas da PKC, das MAPK, e da Pi3K neste processo, ainda não é conhecido. Além disso, pouco se sabe sobre a importância dos leucotrienos na fagocitose via outros receptores. Os objetivos deste trabalho são: a) ampliar o conhecimento sobre as vias de sinalização ativadas pelos leucotrienos durante a fagocitose de hemácias opsonizadas por IgG; b) avaliar o efeito dos leucotrienos na fagocitose de Candida albicans, por macrófagos alveolares e as vias de sinalização intracelular envolvidas. Observou-se que os leucotrienos endogenamente produzidos ou adicionados aos macrófagos alveolares, aumentam a fagocitose via Fc`GAMA´R e para isso utilizam distintas vias de sinalização intracelular. A ação do LTB`IND.4´ envolveu predominantemente a via ERK1/2 e PKC`ALFA´ e com menor intensidade da PKC`DELTA´...

phagocytic activity of peripheral blood macrophages in COPD patients

Macrophages numbers are elevated in the lungs of smokers and those patients with COPD, where they accumulate in the alveoli, bronchioles and small airways. The slow progression and chronicity of COPD parallels the chronic increase of macrophages that is seen in sites of tissue injury / damage and supports the concept that macrophages are at least in part responsible for the pathological consequences. The aim of this work was to study the phagocytic activity of peripheral blood macrophages in COPD patients, either in the stable and during acute exacerbation compared to the normal subjects, which might be reflected on the therapeutic intervention strategies. Prospective case - control study. Seventy subjects were enrolled in this study, divided into two groups: Group I: 50 patients with COPD and Group II: 20 healthy volunteers serving as a control group. All subjects were submitted to ABG analysis, spirometric studies and assessment of phagocytic function, namely phagocytic and lytic indices using opsonised suspension of candida of their peripheral blood macrophages. Results showed a highly significant statistical difference as regards both phagocytic and lytic indices among COPD patients [group 1] and control group [group 2] where both indices were significantly lower among the COPD group as compared to the control group indicating obvious phagocytic dysfunction among peripheral blood macrophages in COPD patients, and both indices were significantly lower in patients in exacerbation than patients in stable state. This study is directed to the evaluation of the phagocytic function of peripheral blood macrophages among COPD patients, results revealed that there is actually a phagocytic dysfunction and that it is not always positively correlating to the severity of the disease. This also draws the attention to the peripheral blood cell population in COPD disease which had not taken its share of proper assessment. Hence, it would be recommended to include the peripheral blood cell population and macrophages in particular while searching in the pathophysiology and management of COPD disease

Xantogranuloma juvenil: presentación de un caso clínico Hospital Militar "Cap. (Av) Guillermo Hernández Jacobsen": Departamento de Pediatria / Youth xantogranulome: a case report: Hospital Militar Capital (Av) Guillermo Hernández Jacobsen: Department of Pediatrics

Los histiocitos son células móviles que se encuentran en el tejido conectivo y que tienen una gran capacidad de fagocitosis, tanto para ingerir células muertas como bacterias invasoras. Por último se encargan de procesar y presentar los antígenos a los linfocitos para que estos elaboren los anticuerpos protectores. La histiocitosis es una agrupación de enfermedades que tiene como característica principal la proliferación anormal de histiocitos en los tejidos, que puede se de varios tipos, cada uno con sus manifestaciones clínicas específicas. El xantogranuloma juvenil es una enfermedad benigna clasificada como una Histiocitosis no X, que afecta principalmente a niños menores de 1 año, en mayor proporción al género masculino. Se trata de una patología tumoral de células histiocíticas que compromete la piel, y en los casos mas graves puede llagar a tener compromiso en otros órganos, siendo el ocular el mas frecuente. Suele ser autorresolutiva en el transcurso del crecimiento del niño.

Fagocitose e viabilidade monocitária de pacientes com esquistossomose mansônica na forma hepatoesplênica submetidos à esplenectomia e ao auto-implante esplênico / Phagocytes rate and cellular viability of the monocytes in patients with hepatosplenic schistosomiasis mansoni who underwent splenectomy and auto-implantation of spleen tissue

Esquistossomose mansônica persiste como problema médico-social no nordeste brasileiro. Em crianças, o tratamento cirúrgico inclui esplenectomia e auto-implante esplênico. Este procedimento reduz a septicemia pós-esplenectomia. O objetivo deste estudo foi analisar a taxa de fagocitose e viabilidade de fagócitos mononucleares em portadores de esquistossomose hepatoesplênica, submetidos à cirurgia, de 1991 a 2001. Dos 22 indivíduos analisados, 11 eram portadores de esquistossomose hepatoesplênica, submetidos à esplenectomia e auto-implante esplênico (Grupo estudo) e 11 eram sadios (Grupo Controle). Os grupos tinham média de idades similar e procediam da mesma zona endêmica (Timbaúba-PE). Não se evidenciou diferença na taxa de fagocitose comparando-se o grupo controle (36,1 por cento±4,9 por cento) e o grupo estudo (33,5 por cento±5,7 por cento), p=0,2773. Todavia, a viabilidade dos fagócitos após estímulo com lipopolissacarídio foi maior (94 por cento) no grupo controle, quando comparado ao grupo estudo (65 por cento), p<0,001. Pode-se concluir que a esplenose assegura função fagocitária normal em monócitos, entretanto, os fagócitos possuem menor viabilidade frente a um estímulo nocivo e duradouro.

Mansonic schistosomiasis remains a medical-social issue in Northeastern Brazil. In children, surgical treatment includes splenectomy and spleen autoimplantation. This procedure reduces post-splenectomy sepsis. The aim of this study was to analyze the phagocyte rate and the cellular viability of monocytes in patients with hepatosplenic schistosomiasis, who underwent splenectomy and spleen autoimplantation from 1991 to 2001. Of the 22 individuals analyzed, 11 were patients who underwent splenectomy and spleen autoimplantation (Study group) and 11 were healthy individuals from the same region (Control group). Both groups presented similar mean age. No difference was found in the phagocyte rate between the control group (36.1 percent±4.9 percent) and study group (33.5 percent±5.7 percent). However, phagocyte viability after stimulation with lipopolysaccharide was higher (94 percent) in control group, when compared to the study group (65 percent), p<0.001. It is possible to hypothesize that monocytes from the study group patients presented a reduced response to the microorganism challenge, in the face of a harmful and long-lasting stimulus.

Fallas en la remoción de cuerpos apoptóticos, una fuente de autoantígenos / Failure in the apoptotic cells clearance, a source of autoantigens

La apoptosis es un proceso de muerte celular crítico para mantener la homeostasis de la célula, por ser uno de los procesos más importantes para mantener el balance entre muerte y proliferación y cuyas deficiencias conducen a enfermedades tales como cáncer y autoinmunidad. Las células apoptóticas expresan en su superficie moléculas como la fosfatidilserina (PS), importantes para su reconocimiento por receptores como los Scavenger presentes en fagocitos profesionales y no profesionales, para su posterior remoción. Alteraciones en la capacidad de remover células apoptóticas son una característica común de enfermedades autoinmunes como el Lupus Eritematoso Sistémico, lo que denota la importancia de un mayor conocimiento acerca de los procesos que regulan la remoción de cuerpos apoptóticos. Con esta revisión se pretende comprender mejor la importancia de la remoción de las células apoptóticas en el desarrollo de enfermedades tales como las autoinmunes

Determinación de IgG en eritrocitos senescentes por un ensayo enzimático con consumo de antiglobulina / Determination of senescent red blood cells bound IgG using an enzyme test based an the consuption of antiglobulin

Durante el envejecimiento de los GR se acumula IgG autóloga sobre la membrana eritrocitaria. Esta IgG esta dirigida a un neo antígeno de senescencia, ubicado en la proteína banda 3. El objetivo de este trabajo fue determinar pequeñas cantidades de IgG en la membrana del GR utilizando un inmunoensayo con antiglobulina conjugada con una enzima. Las suspensiones de GRSe y GRJ fueron incubadas con anti-IgG humana conjugada con fosfatasa alcalina. Se transfirieron alícuotas a microplacas sensibilizadas con IgG humana. Se agregó el sustrato de la enzima y se midió la IgG libre. Las concentraciones de IgG unida a la membrana eritrocitaria en GRSe (13.31 x 10-4(g/(L(1.57 x 10-4) fueron significativamente mayores (p(0.0001) que los valores observados en GR (3.35 x 10-4(g/(L(1.39 x 10-4). Los resultados obtenidos indican que esta metodología constituye una herramienta útil para determinar pequeñas contidades de IgG unida a la membrana eritrocitaria.

Effect of Cysticercus cellulosae fractions on the respiratory burst of pig neutrophils

Neutrófilos, eosinófilos e macrófagos são células que interagem com os parasitas no corpo do hospedeiro desenvolvendo atividade antiparasitária. A reação inicial destes leucócitos é a geração de espécies reativas de oxigênio (ERO) a fim de expulsar os parasitas. No presente trabalho estudou-se o efeito da fração total, de escolex e de membrana de Cysticercus cellulosae sobre a explosão respiratória de neutrófilos de suínos. A produção de peróxido de hidrogênio (H2O2) pelos neutrófilos incubados com as frações de C. cellulosae apresentou acréscimo de 190% (extrato total), 120% (escolex) e 44% (membrana). Alta atividade de catalase (33%, 28% e 28% para extrato total, escolex e membrana respectivamente) foi observada nos neutrófilos incubados com as frações de metacestodeo, podendo representar a própria proteção celular do neutrófilo. Frações de escolex e de membrana aumentaram a capacidade fagocitária dos neutrófilos (44% e 28%, respectivamente). Por outro lado, a fração total do cisticerco não alterou a capacidade fagocitária dos neutrófilos, o que pode estar relacionada com modificações na função da membrana celular causadas pela alta produção de ERO na presença da fração total. O extrato total de C. cellulosae é tóxico para os neutrófilos, indicada pela diminuição da capacidade fagocitária, provavelmente pela indução de alto nível de ERO. A diferença de toxicidade do extrato total, de escolex e de membrana para os neutrófilos pode ocorrer pelo efeito antigênico presente no fluido vesicular no extrato total de C. cellulosae.

Interferência de ondas curtas pulsadas na adesividade e na fagocitose de macrófagos em ratos com desnutrição neonatal / Interference of pulse short waves on macrophage adhesion and phagocytosis in rats with neonatal malnutrition

Tendo em vista a relação estabelecida entre desnutrição neonatal e atividade celular ligada ao sistema imune, macrófagos peritoniais de ratos Wistar machos, desnutridos e recuperados, foram expostos à diatermia de ondas curtas pulsadas (DOCP) e a campo magnético (CM) alternado em frequência ultrabaixa para verificar in vitro as possíveis alterações no índice de aderência.

In view of the established relationships between neonatal malnutrition and the immuno system, peritoneal macrophages of male Wistar rats were exposed to diatermic pulsate short wave (DPSW) and to alterned magnetic field on extreme low frequency, in order to verify in vitro adhesion index and phagocytic activity...

Papel das Yops secretadas por Yersinia sobre a resposta imune do hospedeiro / Role of Yops secreted by Yersinia in the host immune response

O gênero Yersinia compreende três espécies patogênicas para humanos: Y. pestis, Y. enterocolitica e Y. pseudotuberculosis. A patogenicidade de Yersinia está ligada à presença do plasmideo de 70-kb (pYV) que é comum às três espécies e codifica um sistema de secreção do tipo III e um conjunto de proteínas de virulência, incluindo aquelas conhecidas como Yops (Yersinia outer proteins), que são exportadas por este sistema quando as células do hospedeiro são infectadas pela bactéria. Duas Yops translocadoras (YopB e YopD) se inserem na membrana plasmática e funcionam no transporte de seis efetoras (YopO, YopH, YopM, YopJ e YopT) para o citosol da célula do hospedeiro. As Yops efetoras funcionam interferindo em múltiplas vias de sinalização da célula infectada. Como consequência, a resposta imune inata e adaptativa do hospedeiro fica afetada. Este trabalho enfoca o papel das Yops na modulação da resposta imune do hospedeiro

Acute lupus hemophagocytic syndrome: report of a case and review of the literature.

The authors reported a case of systemic lupus erythematosus (SLE) with an unusual presentation. The patient presented with acute febrile illness along with progressive pancytopenia related to increasing hemophagocytic activity of histiocytes in the bone marrow. Concomitant polyarthritis, myositis, nephritis, high titer of antinuclear factor (1:2,560) and positive test for anti-DNA antibody made him fit the diagnostic criteria of SLE. No definite evidence of associated infections was confirmed by bacteriologic, serologic and viral studies. He did not respond to empiric antibiotic therapy but dramatically responded to corticosteroid treatment. Therefore, diagnosis of acute lupus hemophagocytic syndrome was made. The clinical presentation, laboratory diagnosis, and management of the patient are discussed and the literature was reviewed and presented.