Antimycobacterial Precatorin A Flavonoid Displays Antibiofilm Activity against Mycobacterium bovis BCG.

The aim of this study was to evaluate the potential antibiofilm activity of Rhynchosia precatoria (R. precatoria) compounds over Mycobacterium bovis BCG (M. bovis BCG) as a model for Mycobacterium tuberculosis (Mtb). We evaluated the antibiofilm activity as the ability to both inhibit biofilm formation and disrupt preformed biofilms (bactericidal) of R. precatoria compounds, which have been previously described as being antimycobacterials against Mtb. M. bovis BCG developed air-liquid interface biofilms with surface attachment ability and drug tolerance. Of the R. precatoria extracts and compounds that were tested, precatorin A (PreA) displayed the best biofilm inhibitory activity, as evaluated by biofilm biomass quantification, viable cell count, and confocal and atomic force microscopy procedures. Furthermore, its combination with isoniazid at subinhibitory concentrations inhibited M. bovis BCG biofilm formation. Nonetheless, neither PreA nor the extract showed bactericidal effects. PreA is the R. precatoria compound responsible for biofilm inhibitory activity against M. bovis BCG.

Raman spectroscopy and silver nanoparticles for efficient detection of membrane proteins in living cells.

Molecular fingerprints revealed by Raman techniques show great potential for biomedical applications, like disease diagnostic through Raman detection of tumor markers and other molecules in the cell membrane. However, SERS substrates used in membrane molecule studies produce enhanced Raman spectra of high variability and challenging band assignments that limit their application. In this work, these drawbacks are addressed to detect membrane-associated hemoglobin (Hbm) in human erythrocytes through Raman spectroscopy. These cells are incubated with silver nanoparticles (AgNPs) in PBS before Raman measurements. Our results showed that AgNPs form large aggregates in PBS that adhered to the erythrocyte membrane, which enhances Raman scattering by molecules around the membrane, like Hbm. Also, deoxyHb markers may allow Hbmdetection in Raman spectra of oxygenated erythrocytes (oxyRBCs). Raman spectra of oxyRBCs incubated with AgNPs showed enhanced deoxyHb signals with good spectral reproducibility, supporting the Hbmdetection through deoxyHb markers. Instead, Raman spectra of oxyRBCs showed oxyHb bands associated with free cytoplasmic hemoglobin. Other factors influencing Raman detection of membrane proteins are discussed, like bothz-position and dimension of the sample volume. The results encourage membrane protein studies in living cells using Raman spectroscopy, leading to the characterization and diagnostic of different pathologies through a non-invasive technique.

Nanoscale Changes on RBC Membrane Induced by Storage and Ionizing Radiation: A Mini-Review.

The storage lesions and the irradiation of blood cellular components for medical procedures in blood banks are events that may induce nanochanges in the membrane of red blood cells (RBCs). Alterations, such as the formation of pores and vesicles, reduce flexibility and compromise the overall erythrocyte integrity. This review discusses the alterations on erythrocytic lipid membrane bilayer through their characterization by confocal scanning microscopy, Raman, scanning electron microscopy, and atomic force microscopy techniques. The interrelated experimental results may address and shed light on the correlation of biomechanical and biochemical transformations induced in the membrane and cytoskeleton of stored and gamma-irradiated RBC. To highlight the main advantages of combining these experimental techniques simultaneously or sequentially, we discuss how those outcomes observed at micro- and nanoscale cell levels are useful as biomarkers of cell aging and storage damage.

Effects of Untreated Drinking Water at Three Indigenous Yaqui Towns in Mexico: Insights from a Murine Model.

BACKGROUND: Reports in a northwestern Mexico state linked arsenic (As) in drinking water to DNA damage in people from indigenous communities. However, this correlation remains under discussion due to unknown variables related to nutrition, customs, and the potential presence of other metal(oid)s. METHODS: To determine this association, we sampled water from three Yaqui towns (Cócorit, Vícam, and Pótam), and analyzed the metals by ICP-OES. We exposed four separate groups, with five male CD-1 mice each, to provide further insight into the potential effects of untreated drinking water. RESULTS: The maximum concentrations of each metal(oid) in µg·L-1 were Sr(819) > Zn(135) > As(75) > Ba(57) > Mo(56) > Cu(17) > Al(14) > Mn(12) > Se(19). Histological studies revealed brain cells with angulation, satellitosis, and reactive gliosis with significant statistical correlation with Mn and As. Furthermore, the liver cells presented hepatocellular degeneration. Despite the early response, there is no occurrence of both statistical and significative changes in hematological parameters. CONCLUSIONS: The obtained results provide experimental insights to understand the potential effects of untreated water with low As and Mn contents in murine models. This fact is noteworthy because of the development of histological changes on both the brain and liver at subchronic exposure.

Evaluation of gamma irradiation for human norovirus inactivation and its effect on strawberry cells.

Norovirus (NoV) is the leading cause of epidemic and sporadic gastroenteritis worldwide; a high number of those cases are attributed to the consumption of contaminated food. Crop producers have used several strategies to inactivate the virus present in these products and thus stop the NoV transmission chain. Physical methods such as gamma radiation show excellent results in the inactivation of bacteria, but its effect on NoV has been little studied. This study aimed to evaluate the effect of gamma radiation for NoV inactivation, and over the surface topographic characteristics of strawberry cells, as a prototype of soft fruit. A 10% suspension of GII norovirus-positive stool samples were treated with either 200 mg/L of sodium hypochlorite (NaClO) or gamma-irradiated at doses of 5, 10, 15 and 20 kilograys (kGy). Viral inactivation was determined by measuring the integrity of viral capsid using RNase A alone or in combination with proteinase K followed by RT-qPCR. The effect over cellular surface topology characteristics of the fruit was measured by atomic force microscopy (AFM) and confocal microscopy. High doses of radiation (20 kGy) were necessary to detect a significant (p < 0.05) decrease of up to 1.26 log10 viral copy number. This dose significantly (p < 0.05) raises the root means square roughness (Rq), which affects directly the quality and texture of the product. The gamma irradiation doses tested in this study were not enough to inactivate NoV. The allowed gamma irradiation doses for fresh produce does not alter the surface topology of the fruit, but they affect the content of fluorescent compounds, responsible for the antioxidant activity of the fruit.

Atomic force microscopy and Raman spectra profile of blood components associated with exposure to cigarette smoking.

Tobacco smoke contains several compounds with oxidant and pro-oxidant properties with the capability of producing structural changes in biomolecules, as well as cell damage. This work aimed to describe and analyse the effect of tobacco smoke on human blood components, red blood cell (RBC) membrane, haemoglobin (Hb) and blood plasma by Atomic Force Microscopy (AFM) and Raman spectroscopy. Our results indicate that tobacco induced RBC membrane nano-alterations characterized by diminished RBC diameter and increased nano-vesicles formation, and RBC fragility. The Raman spectra profile suggests modifications in chemical composition specifically found in peaks 1135 cm-1, 1156 cm-1, 1452 cm-1 and intensity relation of peaks 1195 cm-1 and 1210 cm-1 of blood plasma and by change of peaks 1338 cm-1, 1357 cm-1, 1549 cm-1 and 1605 cm-1 associated with the pyrrole ring of Hb. The relevance of these results lies in the identification of a profile of structural and chemical alterations that serves as a biomarker of physiological and pathological conditions in the human blood components induced by tobacco exposure using AFM and the Raman spectroscopy as tools for monitoring them.

Lactosylated Albumin Nanoparticles: Potential Drug Nanovehicles with Selective Targeting Toward an In Vitro Model of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) ranks fifth in occurrence and second in mortality of all cancers. The development of effective therapies for HCC is urgently needed. Anticancer drugs targeted to the liver-specific asialoglycoprotein receptors (ASGPRs) are viewed as a promising potential treatment for HCC. ASGPRs facilitate the recognition and endocytosis of molecules, and possibly vehicles with galactose end groups, by the liver. In this study, bovine serum albumin (BSA) was conjugated with lactose using a thermal treatment. The formation of lactosylated BSA (BSA-Lac) was confirmed by a change of the chemical structure, increased molecular mass, and Ricinus communis lectin recognition. Subsequently, the low-crosslinking BSA-Lac nanoparticles (LC BSA-Lac NPs) and high-crosslinking BSA-Lac nanoparticles (HC BSA-Lac NPs) were synthesized. These nanoparticles presented spherical shapes with a size distribution of 560 ± 18.0 nm and 539 ± 9.0 nm, as well as an estimated surface charge of -26 ± 0.15 mV and -24 ± 0.45 mV, respectively. Both BSA-Lac NPs were selectively recognized by ASGPRs as shown by biorecognition, competition, and inhibition assays using an in vitro model of HCC. This justifies pursuing the strategy of using BSA-Lac NPs as potential drug nanovehicles with selective direction toward hepatocellular carcinoma.

Effect of gamma irradiation doses in the structural and functional properties of mice splenic cells.

PURPOSE: Ionizing radiation is nowadays effectively used in cancer treatments. However, the effect of irradiation in immune-system cells is poorly understood and remains controversial. The aim of this work was to determine the effect of γ-irradiation in the structural and functional properties of mice splenic cells. MATERIALS AND METHODS: Structural traits of irradiated splenic cells were evaluated by Atomic Force Microscopy and Raman spectroscopy. Functional properties were measured by gene and protein expression by RT-qPCR and ELISA, respectively. The induced cytotoxic effect was evaluated by MTT assay and the phagocytic capability by flow cytometry. RESULTS: Membrane roughness and molecular composition of splenic adherent cells are not changed by irradiation doses exposure. An increase in transcription of pro-inflammatory cytokines was observed. While protein expression decreased in IL-2 dose-dependent, relevant differences were identified in the anti-inflammatory marker IL-10 at 27 Gy. An increase of cytotoxicity in irradiated cells at 7 Gy and 27 Gy doses was observed, while phagocytosis was slight increased at 7 Gy dose but not statistically significant. CONCLUSIONS: We have demonstrated that γ-irradiation affects the splenic cells and changes the cytokines profile toward a pro-inflammatory phenotype and a tendency to increase the cytotoxicity was found, which implies a stimulation of immune response induced by γ-irradiation.

Specific capture of glycosylated graphene oxide by an asialoglycoprotein receptor: a strategic approach for liver-targeting.

In this work, we report the evaluation of lactosylated graphene oxide (GO-AL) as a potential drug carrier targeted at an asialoglycoprotein receptor (ASGPR) from hepatic cancer cells. Structural-modification, safety evaluation, and functional analysis of GO-AL were performed. The structure and morphology of the composite were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while Raman and FTIR spectroscopy were used to track the chemical modification. For the safe application of GO-AL, an evaluation of the cytotoxic effect, hemolytic properties, and specific interactions of the glycoconjugate were also studied. SEM and AFM analysis of the GO showed graphene sheets with a layer size of 2-3 nm, though a few of them reached 4 nm. The Raman spectra presented characteristic peaks of graphene oxide at 1608 cm-1 and 1350 cm-1, corresponding to G and D bands, respectively. Besides, Si-O peaks for the APTES conjugates of GO were identified by FTIR spectroscopy. No cytotoxic or hemolytic effects were observed for GO samples, thus proving their biocompatibility. The interaction of Ricinus communis lectin confirmed that GO-AL has a biorecognition capability and an exposed galactose structure. This biorecognition capability was accompanied by the determination of the specific absorption of lactosylated GO by HepG2 cells mediated through the asialoglycoprotein receptor. The successful conjugation, hemolytic safety, and specific recognition described here for lactosylated GO indicate its promise as an efficient drug-delivery vehicle to hepatic tissue.

Nanodiamonds and gold nanoparticles to obtain a hybrid nanostructure with potential applications in biomedicine.

Using detonation nanodiamonds and fluorescent nitrogen-vacancy center nanodiamonds, linked to gold nanoparticles, we synthesized two hybrid nanostructures (HGDs) that were subsequently conjugated with a fluorophore. An amplification effect induced by the gold nanoparticles increased the emission spectrum of the fluorophore, maximizing the possibilities for imaging applications of these HGDs. The incubation of the nanostructures with HeLa cells produced no alteration of cell viability after 3 h and showed the presence of nanostructures in the cell cytoplasm at 24 h. These observations also indicate the potential biomedical use of the proposed HGDs.

Molecular recognition of glyconanoparticles by RCA and E. coli K88 - designing transports for targeted therapy.

The targeted drug delivery has been studied as one of the main methods in medicine to ensure successful treatments of diseases. Pharmaceutical sciences are using micro or nano carriers to obtain a controlled delivery of drugs, able to selectively interact with pathogens, cells or tissues. In this work, we modified bovine serum albumin (BSA) with lactose, obtaining a neoglycan (BSA-Lac). Subsequently, we synthesized glyconanoparticles (NPBSA-Lac) with the premise that it would be recognized by microbial galactose specific lectins. NPBSA-Lac were tested for bio-recognition with adhesins of E. coli K88 and Ricinus communis agglutinin I (RCA). Glycation of BSA with lactose was analyzed by electrophoresis, infrared spectroscopy and fluorescence. Approximately 41 lactoses per BSA molecule were estimated. Nanoparticles were obtained using water in oil emulsion method and spheroid morphology with a range size of 300-500 nm was observed. Specific recognition of NPBSA-Lac by RCA and E. coli K88 was displayed by aggregation of nanoparticles analyzed by dynamic light scattering and atomic force microscopy. The results indicate that the lactosylated nanovectors could be targeted at the E. coli K88 adhesin and potentially could be used as a transporter for an antibacterial drug.

Nano alterations of membrane structure on both γ-irradiated and stored human erythrocytes.

PURPOSE: Storage and ionizing radiation of human red blood cells (RBC) produce alterations on RBC membranes and modify their normal shape and functionality. We investigated early morphological and biochemical changes in RBC due to those stressing agents at the nanoscale level and their impact on blood quality. MATERIALS AND METHODS: Whole blood samples from healthy donors were γ-irradiated with 15, 25, 35, and 50 Gy. Non-irradiated and non-stored RBC were used as control samples. Irradiated blood samples were stored separately at 4 °C and analyzed immediately and after 5 and 13 d. Atomic force microscopy (AFM), osmotic fragility and Raman spectroscopy were used to detect morphological and biochemical changes. RESULTS: RBC function is challenged by both irradiation and storage. The storage procedure caused nanometric variations over the surface of RBC membrane for both irradiated and non-irradiated cells. The membrane of RBC became more fragile, while the biochemical fingerprint of hemoglobin (Hb) remained unaltered. CONCLUSIONS: Our work shows that the irradiation procedure leads to an increase in the number and size of nanovesicles along with the dose. The functionality of RBC can be affected from changes in the roughness, becoming more fragile and susceptible to breakage.

Characterization of antigen-presenting cells from the porcine respiratory system.

Antigen-presenting cells (APCs) are strategically placed in all anatomic sites with high antigen exposure such as the respiratory system. The aim of this study was to evaluate phenotypic and functional properties of APCs from the lung (L-Cs), mediastinal lymph node (LN-Cs) and bronchoalveolar lavage cells (BAL-Cs). The APCs were first analyzed based on forward scatter and side scatter profiles and the selection of MHC-II(high)CD172a(+) cells (referred to as APCs); then the expression of CD1a, CD163, CD206, CD16 and CD11R3 was evaluated in the APCs. The results showed that CD1a, CD163 and CD206 were differentially expressed among L-Cs, LN-Cs and BAL-Cs, suggesting the phenotype MHC-II(high)CD172a(+)CD1a(low/-)CD163(low)CD206(-) for L-Cs and MHC-II(high)CD172a(+)CD1a(+)CD163(low/-)CD206(+) for LN-Cs. BAL-Cs were MHC-II(high)CD172a(+)CD1a(-)CD163(high)CD206(+/-). The functional characteristics of L-Cs and LN-Cs were different from those of BAL-Cs, confirming that L-Cs and LN-Cs resemble specialized APCs. In conclusion, we present the characterization of APCs from L-Cs, LN-Cs and BAL-Cs of the porcine respiratory system.

Production of interferon α and ß, pro-inflammatory cytokines and the expression of suppressor of cytokine signaling (SOCS) in obese subjects infected with influenza A/H1N1.

BACKGROUND & AIMS: Obesity was recognized as an independent risk factor for morbidity and mortality during last influenza A/H1N1 pandemic. Mechanisms involved in the high mortality risk from obesity during influenza A virus include reduced type I interferon production and delayed pro-inflammatory response, which lead to a higher rate of morbidity and mortality in murine models. In this study, we evaluated the production of type I interferons, pro-inflammatory and anti-inflammatory cytokines in peripheral blood mononuclear cells (PBMCs) from obese and lean subjects with and without confirmed infection of influenza A/H1N1. The expression levels of the suppressor of cytokine signaling-1 (SOCS1), SOCS3 and nuclear factor-kB were also evaluated. METHODS: Cytokines were measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and/or by ELISA in PBMCs stimulated with toll like receptor-3 (TLR-3) and TLR-7 ligands. The mRNA expression of SOCS1 and SOCS3 were evaluated by qRT-PCR. RESULTS: The obese volunteers infected with influenza A/H1N1 showed a diminished ability to produce type I interferon in response to TLR-3 ligand. Interestingly, the pro-inflammatory response was also affected in TLR-3 stimulated PBMCs. Obese influenza-free volunteers showed an increased basal expression of SOCS3, but not SOCS1. During influenza infection, SOCS1 and SOCS3 expression was higher in the lean infected volunteers in contrast to those who were obese infected. CONCLUSIONS: These data suggest that obesity is related to TLR-3 impairment and explain, at least in part, the inadequate immune response of obese individuals during infection with influenza A/H1N1 virus.

Swine, human or avian influenza viruses differentially activates porcine dendritic cells cytokine profile.

Swine influenza virus (SwIV) is considered a zoonosis and the fact that swine may act as an intermediate reservoir for avian influenza virus, potentially infectious for humans, highlights its relevance and the need to understand the interaction of different influenza viruses with the porcine immune system. Thus, in vitro porcine bone marrow-derived dendritic cell (poBMDCs) were infected with a circulating SwIV A/Swine/Spain/SF32071/2007(H3N2), 2009 human pandemic influenza virus A/Catalonia/63/2009(H1N1), low pathogenic avian influenza virus (LPAIV) A/Anas plathyrhynchos/Spain/1877/2009(aH7N2) or high pathogenic avian influenza virus (HPAIV) A/Chicken/Italy/5093/1999(aH7N1). Swine influenza virus H3N2 infection induced an increase of SLA-I and CD80/86 at 16 and 24h post infection (hpi), whereas the other viruses did not. All viruses induced gene expression of NF-κB, TGF-ß, IFN-ß and IL-10 at the mRNA level in swine poBMDCs to different extents and in a time-dependent manner. All viruses induced the secretion of IL-12 mostly at 24hpi whereas IL-18 was detected at all tested times. Only swH3N2 induced IFN-α in a time-dependent manner. Swine H3N2, aH7N2 and aH7N1 induced secretion of TNF-α also in a time-dependent manner. Inhibition of NF-κB resulted in a decrease of IFN-α and IL-12 secretion by swH3N2-infected poBMDC at 24hpi, suggesting a role of this transcription factor in the synthesis of these cytokines. Altogether, these data might help in understanding the relationship between influenza viruses and porcine dendritic cells in the innate immune response in swine controlled through soluble mediators and transcription factors.

Porcine reproductive and respiratory syndrome virus induces CD4+CD8+CD25+Foxp3+ regulatory T cells (Tregs).

The aim of this study was to analyze the regulatory T cells (Tregs) induced by the porcine reproductive and respiratory syndrome virus (PRRSV) in pigs. Serum, blood, tonsil, and mediastinal lymph nodes' samples were obtained at different time post-infection (dpi). The frequencies of CD4(+)CD8(-)CD25(+)Foxp3(+), CD4(+)CD8(+)CD25(+)Foxp3(+), or CD4(-)CD8(+)CD25(+)Foxp3(+) phenotypes were determined in PBMC and lymph node cells, and cells producing IL-10 or TGF-ß were analyzed. PRRSV increased the number of CD4(+)CD8(+)CD25(+)Foxp3(+) cells at 14 dpi, whereas CD4(+)CD8(-)CD25(+)Foxp3(+) remained constant until 28 dpi. Positive correlation exists between viremia and induced regulatory cells. CD4(+)CD8(+)CD25(+)Foxp3(+)-induced Treg cells were consistently observed in lymphoid tissues. Analysis of IL-10- and TGF-ß-producing cell demonstrated that in response to PRRSV, CD4(+)CD8(-)Foxp3(low) and CD4(+)CD8(+)Foxp3(high) cells increase moderately the proportion of IL-10(+) cells. TGF-ß was only observed in the CD4(+)CD8(+)Foxp3(high) population after PRRSV stimulation. In conclusion, PRRSV infection increases the frequency of Tregs with the phenotype CD4(+)CD8(+)CD25(+)Foxp3(high) and produces TGF-ß.

Antioxidant capacity of binuclear Cu(II)-cyclophanes, insights from two synthetic bioactive molecules.

The compounds 2,9,25,32-tetraoxo-4,7,27,30-tetrakis(carboxymethyl)-1,4,7,10,24,27,30,33-octaaza-17,40-dioxa[10.1.10.1]paracyclophane and 2,9,25,32-tetraoxo-4,7,27,30-tetrakis(carboxymethyl)-1,4,7,10,24,27,30,33-octaaza[10.1.10.1]paracyclophane binuclear copper complexes (Cu2PO and Cu2PC, respectively) were studied by determining their antioxidant capacity using the TROLOX equivalent antioxidant capacity (TEAC) assay, and their cytotoxicity on cultured cells, as well as the superoxide dismutase (SOD)-like activity. Cu2PO had an antioxidant capacity (0.1 g eq TROLOX mol−1) within the order of magnitude of ascorbic acid, and both, Cu2PO and Cu2PC were nontoxic to cultured peripheral mononuclear blood cells. The SOD-like activity was evaluated using the nitroblue tetrazolium assay, and both compounds presented an excellent activity: for Cu2PO, the IC50 was 52 nM and for Cu2PC an IC50 of 0.5 µM was obtained comparable to CuZn SOD IC50 17 nM (Fernandes et al., J Inorg Biochem 2007;101:849­858). These results suggest that synthetic binuclear macrocycles are good candidates to be used as synthetic bioactive molecules with applications in biomedicine.

European genotype of porcine reproductive and respiratory syndrome (PRRSV) infects monocyte-derived dendritic cells but does not induce Treg cells.

The aim of this study was to characterize the immune responses of DCs after infection with four different EU strains of PRRSV and whether they show any ability to immunomodulate T cells activation. Our results show that all EU strains can efficiently infect and replicate in DCs. Nevertheless, SLA-II levels remained unaltered in DC infected by all EU PRRSV strains, whereas SLA-I expression was only reduced when strain 2992 was used. IL-10 production was induced by three EU PRRSV strains, being strain 2992 the highest inducer. However, no induction of Treg cells, measured by CD25 and Foxp3 expression on lymphocytes co-cultured with infected DCs, was found. TGF-beta induction was not detected in DC infected with any EU strain tested. In conclusion, DCs infected with EU PRRSV strains exhibited an unbalanced ability to stimulate T cell response and was strain dependent. However, Treg cells were not induced, at least in vitro.

Induction of T helper 3 regulatory cells by dendritic cells infected with porcine reproductive and respiratory syndrome virus.

Delayed development of virus-specific immune response has been observed in pigs infected with the porcine reproductive and respiratory syndrome virus (PRRSV). Several studies support the hypothesis that the PRRSV is capable of modulating porcine immune system, but the mechanisms involved are yet to be defined. In this study, we evaluated the induction of T regulatory cells by PRRSV-infected dendritic cells (DCs). Our results showed that PRRSV-infected DCs significantly increased Foxp3(+)CD25(+) T cells, an effect that was reversible by IFN-alpha treatment, and this outcome was reproducible using two distinct PRRSV strains. Analysis of the expressed cytokines suggested that the induction of Foxp3(+)CD25(+) T cells is dependent on TGF-beta but not IL-10. In addition, a significant up-regulation of Foxp3 mRNA, but not TBX21 or GATA3, was detected. Importantly, our results showed that the induced Foxp3(+)CD25(+) T cells were able to suppress the proliferation of PHA-stimulated PBMCs. The T cells induced by the PRRSV-infected DCs fit the Foxp3(+)CD25(+) T helper 3 (Th3) regulatory cell phenotype described in the literature. The induction of this cell phenotype depended, at least in part, on PRRSV viability because IFN-alpha treatment or virus inactivation reversed these effects. In conclusion, this data supports the hypothesis that the PRRSV succeeds to establish and replicate in porcine cells early post-infection, in part, by inducing Th3 regulatory cells as a mechanism of modulating the porcine immune system.

Efecto del virus del síndrome reproductivo y respiratorio porcino (PRRS) en células dendríticas de cerdo derivadas de monocitos / Effect of porcine reproductive and respiratory syndrome (PRRS) virus on porcine monocyte-derived dendritic cells

Dendritic cells (DC) are considered the most important antigen presenting cells of the immune system. Its anatomical location (skin, mucosa and peripheral blood), the expression of receptors to recognize pathogens, the expression of co-stimulatory molecules (CD80/86), the major histocompatibility complex (MHC) class I and II, and the production of cytokines (such as IFN-α, IL-10, IL-12) confers to these cells the characteristic to regulate innate and adaptive immune responses. The objective of this work was to evaluate the effects of the porcine reproductive and respiratory virus (PRRS) in mature DC. DC were generated from blood monocytes using IL-4 and GM-CSF and were stimulated with lipopolysaccharide (LPS) to induce their maturation. The results show that the expression of CD14 and CD172a molecules in infected DC was not affected, while MHC II and CD80/86 expression was diminished. This decrease seems to affect the allogenic proliferation of lymphocytes stimulated with infected DC. On the other hand, the virus increases mRNA expression of IL-10 and TNF-α, and diminishes that for IL-1 β and IL-6. The results obtained could explain, in part, the immunophatology of the disease.

Las células dendríticas (DC) son las presentadoras de antígeno más importantes del sistema inmune. Su localización anatómica (piel, mucosas y sangre periférica), la expresión de receptores para reconocer patógenos, la expresión de moléculas de coestimulación (CD80/86), del complejo principal de histocompatibilidad (MHC) clases I y II, y la producción de citocinas (IFN-α, IL-10, IL-12), les confiere una característica única para regular las respuestas inmune innata y adaptativa. El objetivo de este trabajo fue evaluar el efecto del virus de síndrome reproductivo y respiratorio porcino (PRRS) en DC maduras. Se generaron células dendríticas a partir de monocitos utilizando IL-4 y GM-CSF y se estimularon con lipopolisacárido (LPS) para inducir su maduración. Los resultados muestran que la expresión de las moléculas CD14 y CD172a no se altera en las DC infectadas, mientras que la expresión de MHC II y CD80/86 se ve disminuida. Esta disminución parece afectar la proliferación alogénica de linfocitos estimulados con DC infectadas. Asimismo, el virus aumenta la expresión del ARNm de IL-10 y TNF-α, y disminuye la de IL-1 β e IL-6. Lo anterior explica, en parte, la inmunopatología de la enfermedad.