A low-anticoagulant heparin suppresses metastatic dissemination through the inhibition of tumor cell-platelets association.

Metastasis is the leading cause of cancer-related deaths. Despite this relevance, there is no specific therapy targeting metastasis. The interaction of the tumor cell with platelets, forming microemboli is crucial for successful hematogenous dissemination. Heparin disrupts it by a P-selectin-mediated event. However, its clinical use for this purpose is hindered by the requirement of high doses, leading to anticoagulant-related side effects. In this study, we obtained a low-anticoagulant heparin through the fractionation of a pharmaceutical bovine heparin. This derivative was referred to as LA-hep and we investigated its efficacy in inhibiting metastases and explored its capacity of suppressing the interaction between tumor cells and platelets. Our data revealed that LA-hep is as efficient as porcine unfractionated heparin in attenuating lung metastases from melanoma and colon adenocarcinoma cells in an assay with a single intravenous administration. It also prevents platelet arrest shortly after cell injection in wild-type mice and suppresses melanoma-platelets interaction in vitro. Moreover, LA-hep blocks P-selectin's direct binding to tumor cells and platelet aggregation, providing further evidence for the role of P-selectin as a molecular target. Even in P-selectin-depleted mice which developed a reduced number of metastatic foci, both porcine heparin and LA-hep further inhibited metastasis burden. This suggests evidence of an additional mechanism of antimetastatic action. Therefore, our results indicate a dissociation between the heparin anticoagulant and antimetastatic effects. Considering the simple and highly reproducible methodology used to purify LA-hep along with the data presented here, LA-hep emerges as a promising drug for future use in preventing metastasis in cancer patients.

Direct antitumoral effects of sulfated fucans isolated from echinoderms: a possible role of neuropilin-1/ß1 integrin endocytosis and focal adhesion kinase degradation.

Hypercoagulability, a major complication of metastatic cancers, has usually been treated with heparins from natural sources, or with their synthetic derivatives, which are under intense investigation in clinical oncology. However, the use of heparin has been challenging for patients with risk of severe bleeding. While the systemic administration of heparins, in preclinical models, has shown primarily attenuating effects on metastasis, their direct effect on established solid tumors has generated contradictory outcomes. We investigated the direct antitumoral properties of two sulfated fucans isolated from marine echinoderms, FucSulf1 and FucSulf2, which exhibit anticoagulant activity with mild hemorrhagic potential. Unlike heparin, sulfated fucans significantly inhibited tumor cell proliferation (by ~30-50%), and inhibited tumor migration and invasion in vitro. We found that FucSulf1 and FucSulf2 interacted with fibronectin as efficiently as heparin, leading to loss of prostate cancer and melanoma cell spreading. The sulfated fucans increased the endocytosis of ß1 integrin and neuropilin-1 chains, two cell receptors implicated in fibronectin-dependent adhesion. The treatment of cancer cells with both sulfated fucans, but not with heparin, also triggered intracellular focal adhesion kinase (FAK) degradation, with a consequent overall decrease in activated focal adhesion kinase levels. Finally, only sulfated fucans inhibited the growth of B16-F10 melanoma cells implanted in the dermis of syngeneic C57/BL6 mice. FucSulf1 and FucSulf2 arise from this study as candidates for the design of possible alternatives to long-term treatments of cancer patients with heparins, with the advantage of also controlling local growth and invasion of malignant cells.

Influence of killer immunoglobulin-like receptors genes on the recurrence rate of ocular toxoplasmosis in Brazil.

BACKGROUND: Recurrence is a hallmark of ocular toxoplasmosis (OT), and conditions that influence its occurrence remain a challenge. Natural killer cells (NK) are effectors cells whose primary is cytotoxic function against many parasites, including Toxoplasma gondii. Among the NK cell receptors, immunoglobulin-like receptors (KIR) deserve attention due to their high polymorphism. OBJECTIVES: This study aimed to analyse the influence of KIR gene polymorphism in the course of OT infection and its association with recurrences after an active episode. METHODS: Ninety-six patients from the Ophthalmologic Clinic of the National Institute of Infectology Evandro Chagas were followed for up to five years. After DNA extraction, genotyping of the patients was performed by polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) utilising Luminex equipment for reading. During follow-up, 60.4% had a recurrence. FINDINGS: We identified 25 KIR genotypes and found a higher frequency of genotype 1 (31.7%) with worldwide distribution. We note that the KIR2DL2 inhibitor gene and the gene activator KIR2DS2 were more frequent in patients without recurrence. Additionally, we observed that individuals who carry these genes progressed recurrence episodes slowly compared to individuals who do not carry these genes. MAIN CONCLUSIONS: The KIR2DL2 and KIR2DS2 are associated as possible protection markers against ocular toxoplasmosis recurrence (OTR).

Revisiting the Syndecans: Master Signaling Regulators with Prognostic and Targetable Therapeutic Values in Breast Carcinoma.

Syndecans (SDC1 to 4), a family of cell surface heparan sulfate proteoglycans, are frequently expressed in mammalian tissues. SDCs are aberrantly expressed either on tumor or stromal cells, influencing cancer initiation and progression through their pleiotropic role in different signaling pathways relevant to proliferation, cell-matrix adhesion, migration, invasion, metastasis, cancer stemness, and angiogenesis. In this review, we discuss the key roles of SDCs in the pathogenesis of breast cancer, the most common malignancy in females worldwide, focusing on the prognostic significance and molecular regulators of SDC expression and localization in either breast tumor tissue or its microenvironmental cells and the SDC-dependent epithelial-mesenchymal transition program. This review also highlights the molecular mechanisms underlying the roles of SDCs in regulating breast cancer cell behavior via modulation of nuclear hormone receptor signaling, microRNA expression, and exosome biogenesis and functions, as well as summarizing the potential of SDCs as promising candidate targets for therapeutic strategies against breast cancer.

A construção do caso clínico como recurso no tratamento das urgências subjetivas / The construction of the clinical case as a resource in the treatment of subjective urgencies

Este trabalho discute a metodologia psicanalítica de investigação - construção do caso clínico - como recurso no tratamento das urgências subjetivas. A palavra trazida pelo sujeito que chega à instituição hospitalar psiquiátrica é recolhida como ponto norteador do tratamento, enquanto as narrativas da família e instituição também são convocadas a compor o caso. A partir da construção do caso clínico de João, verificamos a ruptura que se produz no enunciado do sujeito psicótico frente ao Outro absoluto e concreto, fazendo irromper a urgência. A posição de secretariamento adotada pela equipe na figura da analista, entretanto, suscita fragmentos de discurso que aos poucos vão dando sustentação à casa-corpo do sujeito. Essa saída inédita por ele apresentada oferta à prática elementos para pensar possíveis tratamentos ao Outro e passagem ao ato na psicose.

Tumor-Released Products Promote Bone Marrow-Derived Macrophage Survival and Proliferation.

Macrophages play a central role within the tumor microenvironment, with relevant implications for tumor progression. The modulation of their phenotype is one of the mechanisms used by tumors to escape from effective immune responses. This study was designed to analyze the influence of soluble products released by tumors, here represented by the tumor-conditioned media of two tumor cell lines (3LL from Lewis lung carcinoma and MN/MCA from fibrosarcoma), on murine macrophage differentiation and polarization in vitro. Data revealed that tumor-conditioned media stimulated macrophage differentiation but influenced the expression levels of macrophage polarization markers, cytokine production, and microRNAs of relevance for macrophage biology. Interestingly, tumor-derived soluble products supported the survival and proliferation rate of bone marrow precursor cells, an effect observed even with mature macrophages in the presence of M2 but not M1 inducers. Despite presenting low concentrations of macrophage colony-stimulating factor (M-CSF), tumor-conditioned media alone also supported the proliferation of cells to a similar extent as exogenous M-CSF. This effect was only evident in cells positive for the expression of the M-CSF receptor (CD115) and occurred preferentially within the CD16+ subset. Blocking CD115 partially reversed the effect on proliferation. These results suggest that tumors release soluble products that not only promote macrophage development from bone marrow precursors but also stimulate the proliferation of cells with specific phenotypes that could support protumoral functions.

Manganese systemic distribution is modulated in vivo during tumor progression and affects tumor cell migration and invasion in vitro.

Metastatic disease remains the leading cause of death in cancer and understanding the mechanisms involved in tumor progression continues to be challenging. This work investigates the role of manganese in tumor progression in an in vivo model of tumor growth. Our data revealed that manganese accumulates within primary tumors and secondary organs as manganese-rich niches. Consequences of such phenomenon were investigated, and we verified that short-term changes in manganese alter cell surface molecules syndecan-1 and ß1-integrin, enhance collective cell migration and invasive behavior. Long-term increased levels of manganese do not affect cell growth and viability but enhance cell migration. We also observed that manganese is secreted from tumor cells in extracellular vesicles, rather than in soluble form. Finally, we describe exogenous glycosaminoglycans that counteract manganese effects on tumor cell behavior. In conclusion, our analyses describe manganese as a central element in tumor progression by accumulating in Mn-rich niches in vivo, as well as in vitro, affecting migration and extracellular vesicle secretion in vitro. Manganese accumulation in specific regions of the organism may not be a common ground for all cancers, nevertheless, it represents a new aspect of tumor progression that deserves special attention.

Maternidade e foraclusão: A equação filho-kakon / Maternity and forclusion: Son-kakon equation / Maternidad y forclusión: La ecuación hijo-kakon

A maternidade está articulada à relação da mulher com a falta; contudo, a falta nem sempre está articulada ao falo, à castração. Que lugar a criança ocupa, qual o lugar para a maternidade, quando não há recurso à significação fálica? Um caso clínico nos permite interrogar qual o lugar do filho quando a significação fálica não é operante e a gravidez revela a foraclusão. Uma passagem ao ato durante a gestação evidencia como o bebê pode se converter em "kakon", objeto mau a ser eliminado. A angústia experimentada, neste caso, não é a angústia-sinal do neurótico, que enquadra a fantasia construída em resposta ao desejo do Outro. É uma angústia enorme, a céu aberto. Para o psicótico, não é possível responder ao desejo do Outro pela fantasia. Se, na neurose, o objeto a, extraído da castração, pode funcionar como uma resposta ao Outro, na psicose o sujeito se vê identificado a esse objeto. Ele encarna o objeto e a angústia fica sem contenção alguma. O bebê é o próprio objeto estranho, inimigo interior a ser eliminado, o verdadeiro "kakon".

Maternity is linked to the woman's relationship with the lack; however, the lack is not always linked to the phallus, to castration. What is the place of the child, where is the place for maternity, when there is no recourse to phallic significance? A clinical case allows us to question the place of the child when the phallic significance is not operable and the pregnancy reveals the forclusion. A passage to the act during the pregnancy shows how the baby can become a "kakon", a bad object to be eliminated. The anguish experienced in this case is not the neurotic signal anguish, which frames the fantasy constructed in response to the Other's desire. It is a huge, unconcealed anguish. For the psychotic, it is not possible to respond to the Other's desire for fantasy. If in the neurosis, the object a, extracted from castration, can function as a response to the Other, in psychosis the subject is identified with that object. He embodies the object and the anguish runs out of containment. The baby is its own foreign object, the inner enemy to be eliminated, the true "kakon".

La maternidad está vinculada a la relación de la mujer con la falta; sin embargo, la falta no siempre está vinculada al falo, a la castración. ¿Qué lugar el niño ocupa, cuál es el lugar para la maternidad cuando no hay recurso a la significación fálica? Un caso clínico nos permite interrogar cuál es el lugar del hijo cuando la significación fálica no es operante y el embarazo revela la forclusión. Un pasaje al acto durante el embarazo evidencia cómo el bebé puede convertirse en "kakon", objeto malo a ser eliminado. La angustia experimentada, en este caso, no es la angustia-señal del neurótico, que encuadra la fantasía construida en respuesta al deseo del Otro. Es una angustia inmensa, a plena vista. Para el psicótico, no es posible responder al deseo del Otro por la fantasía. Si, en la neurosis, el objeto a, extraído de la castración, puede funcionar como respuesta al Otro, en la psicosis el sujeto se percibe identificado a ese objeto. Él encarna el objeto y la angustia se queda sin contención. El bebé es el propio objeto extraño, enemigo interior a ser eliminado, el verdadero "kakon".

I Fórum Latino-Americano de Saúde Mental na Pandemia: desafios, panorama atual e perspectivas futuras / I Latin American Forum of Mental Health in the Pandemic: challenges, current outlook and future prospects

O I Fórum Latino-Americano de Saúde Mental na Pandemia, ocorrido em dezembro de 2020, apresentou 18 estudos desenvolvidos em 13 universidades e instituições do Brasil, Argentina, Chile, Guatemala e Cuba. Os trabalhos foram divididos em cinco mesas: "Correlatos psicológicos da pandemia na população em geral", "Estudos sobre o efeito psicológico e biológico em populações específicas", "Aspectos da pandemia sobre mulheres grávidas e recém-nascidos", "Infância e adolescência na pandemia", e "Terapia e psicologia positiva em tempos de pandemia". O objetivo deste artigo de perspectivas é divulgar as pesquisas expostas e refletir a respeito das principais tendências. Assim, apresenta-se uma síntese de cada trabalho, objetivos e resultados. Os estudos apontam para um aumento nos sintomas de estresse, ansiedade e depressão na população em geral e em grupos específicos como crianças, grávidas, puérperas, profissionais da saúde e imigrantes. Foram sugeridos como possíveis preditores de sofrimento psicológico: exposição excessiva às notícias, insônia, sedentarismo, sexo feminino, jovens, baixa escolaridade, baixa renda, desemprego, abuso emocional ou físico, e diagnóstico de transtorno mental. Os estudos apresentados encontram-se em andamento, portanto os dados não são conclusivos. Por fim, as perspectivas e tendências apontadas pelas pesquisas foram discutidas. Em razão da crescente demanda por atendimento psicoterápico, e da escassez de profissionais, principalmente em áreas remotas, o desenvolvimento de novas abordagens de intervenção e promoção da saúde mental são encorajadas.(AU)

The I Latin American Forum on Mental Health in Pandemic, held in December 2020, presented 18 studies developed in 13 universities and institutions in Brazil, Argentina, Chile, Guatemala and Cuba. The studies were divided into five tables: "Psychological correlates of the pandemic in the general population", "Studies on the psychological and biological effect in specific populations", "Aspects of the pandemic on pregnant women and newborns", "Childhood and adolescence in pandemic ", and" Therapy and positive psychology in times of pandemic ". The purpose of this perspective article is to disseminate the research exposed in the forum and reflect about their central trends. Thus, a summary of each work, objectives and results is presented. The studies point to an increase in the symptoms of stress, anxiety and depression in the general population and in specific groups such as children, pregnant women, mothers, health professionals and immigrants. The following factors were suggested as possible predictors of psychological distress: excessive exposure to news, insomnia, physical inactivity, female sex, youth, low education, low income, unemployment, emotional or physical abuse, and diagnosis of mental disorder. The studies presented are ongoing, so the data are not conclusive. Finally, the perspectives and trends pointed out by the surveys were discussed. Due to the growing demand for psychotherapeutic care, and the shortage of professionals, especially in remote areas, the development of new approaches to intervention and promotion of mental health are encouraged.(AU)

El I Foro Latinoamericano de Salud Mental en Pandemia, realizado en diciembre de 2020, presentó 18 estudios desarrollados en 13 universidades e instituciones de Brasil, Argentina, Chile, Guatemala y Cuba. Los trabajos se dividieron en cinco tablas: "Correlaciones psicológicas de la pandemia en la población general", "Estudios sobre el efecto psicológico y biológico en poblaciones específicas", "Aspectos de la pandemia en mujeres embarazadas y recién nacidos", "Infancia y adolescencia en pandemia ", y" Terapia y psicología positiva en tiempos de pandemia ". El objetivo de este artículo de perspectivas es difundir las investigaciones expuestas y reflexionar sobre las principales tendencias. Así, se presenta un resumen de cada trabajo, objetivos y resultados. Los estudios apuntan a un aumento de los síntomas de estrés, ansiedad y depresión en la población general y en grupos específicos como niños, mujeres embarazadas, madres, profesionales de la salud e inmigrantes. Se sugirieron los siguientes como posibles predictores de angustia psicológica: exposición excesiva a noticias, insomnio, inactividad física, sexo femenino, juventud, baja educación, bajos ingresos, desempleo, abuso emocional o físico y diagnóstico de trastorno mental. Los estudios presentados están en curso, por lo que los datos no son concluyentes. Finalmente, se discutieron las perspectivas y tendencias señaladas por las encuestas. Debido a la creciente demanda de atención psicoterapéutica y la escasez de profesionales, especialmente en áreas remotas, se fomenta el desarrollo de nuevos enfoques de intervención y promoción de la salud mental.(AU)

Modulation of cytokine production by monocytes and developing-dendritic cells under the influence of leukemia and lymphoma cell products.

Cytokines and other soluble factors released by tumor cells play an important role in modulating immune cells to favor tumor development. Monocyte differentiation into macrophages or dendritic cells (DCs) with specific phenotypes is deeply affected by tumor signals and understanding this context is paramount to prevent and propose new therapeutic possibilities. Hence, we developed a study to better describe the modulatory effects of leukemia and lymphoma cell products on human monocytes and monocyte-derived DCs secretion of cytokines such as interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α), IL-6, and IL-12. Except with the promyelocytic leukemia cell supernatants (HL-60), the other two tumor supernatants (chronic myeloid leukemia, K562 and Burkitt lymphoma, DAUDI) increased both TNF-α and IL-1ß production by monocytes and monocytes undergoing differentiation. This effect was neither explained by alterations of cell number in culture nor by the high amount of vascular endothelial growth factor (VEGF) present in the tumor supernatants. Moreover, all supernatants used were able to induce drastic reduction of IL-12 secretion by cells induced to activation, suggesting a negative interference with Th1 antitumoral responses that should be a huge advantage for tumor progression.

HS2ST1-dependent signaling pathways determine breast cancer cell viability, matrix interactions, and invasive behavior.

Heparan sulfate proteoglycans (HSPGs) act as signaling co-receptors by interaction of their sulfated glycosaminoglycan chains with numerous signaling molecules. In breast cancer, the function of heparan sulfate 2-O-sulfotransferase (HS2ST1), the enzyme mediating 2-O-sulfation of HS, is largely unknown. Hence, a comparative study on the functional consequences of HS2ST1 overexpression and siRNA knockdown was performed in the breast cancer cell lines MCF-7 and MDA-MB-231. HS2ST1 overexpression inhibited Matrigel invasion, while its knockdown reversed the phenotype. Likewise, cell motility and adhesion to fibronectin and laminin were affected by altered HS2ST1 expression. Phosphokinase array screening revealed a general decrease in signaling via multiple pathways. Fluorescent ligand binding studies revealed altered binding of fibroblast growth factor 2 (FGF-2) to HS2ST1-expressing cells compared with control cells. HS2ST1-overexpressing cells showed reduced MAPK signaling responses to FGF-2, and altered expression of epidermal growth factor receptor (EGFR), E-cadherin, Wnt-7a, and Tcf4. The increased viability of HS2ST1-depleted cells was reduced to control levels by pharmacological MAPK pathway inhibition. Moreover, MAPK inhibitors generated a phenocopy of the HS2ST1-dependent delay in scratch wound repair. In conclusion, HS2ST1 modulation of breast cancer cell invasiveness is a compound effect of altered E-cadherin and EGFR expression, leading to altered signaling via MAPK and additional pathways.

An NGS-based HLA haplotype analysis and population comparison between two cities in Rio de Janeiro, Brazil.

HLA genes can exhibit extensive variations in frequency, especially in highly admixed populations, such as that of Brazil. In this study, we demonstrated NGS-based HLA typing in our laboratory using an Illumina HiSeq 2500 sequencing platform and downstream analysis. We herein describe and compare the allele and haplotype frequencies of the populations in Barra Mansa (BM) and Rio de Janeiro (RJ), using the acquired genetic data. Sequences encompassing 7 HLA loci (HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1, HLA-DPA1, and HLA-DPB1) were amplified from a total of 1435 bone marrow samples donated by volunteers recruited in BM (37.56%) and RJ (62.44%) using polymerase chain reactions, and were sequenced using five distinct HiSeq 2500 runs. Alleles were analyzed to generate 2-locus haplotypes and extended haplotypes encompassing more than two loci. The most frequent haplotype was A*01:01:01~C*07:01:01~B*08:01:01~DRB1*03:01:01~DQB1*02:01:01~DPA1*01:03:01~DPB1*04:01:01 in both populations. The populations of BM and RJ exhibited a significant difference in genetic composition (P = .03) but not in genetic variance (P = .45). However, some groups of subjects, classified based on self-declared ethnicity, particularly Branca and Preta, displayed significant genetic variance (P < .05). In conclusion, these genetic data indicate no differences in HLA loci between the populations of these two cities, but were informative with respect to variations in ancestry composition.

Non-Anticoagulant Heparan Sulfate from the Ascidian Phallusia nigra Prevents Colon Carcinoma Metastasis in Mice by Disrupting Platelet-Tumor Cell Interaction.

Although metastasis is the primary cause of death in patients with malignant solid tumors, efficient anti-metastatic therapies are not clinically available currently. Sulfated glycosaminoglycans from marine sources have shown promising pharmacological effects, acting on different steps of the metastatic process. Oversulfated dermatan sulfates from ascidians are effective in preventing metastasis by inhibition of P-selectin, a platelet surface protein involved in the platelet-tumor cell emboli formation. We report in this work that the heparan sulfate isolated from the viscera of the ascidian Phallusia nigra drastically attenuates metastases of colon carcinoma cells in mice. Our in vitro and in vivo assessments demonstrate that the P. nigra glycan has very low anticoagulant and antithrombotic activities and a reduced hypotension potential, although it efficiently prevented metastasis. Therefore, it may be a promising candidate for the development of a novel anti-metastatic drug.

Metal ions and the extracellular matrix in tumor migration.

In this review, we explore the roles of divalent metal ions in structure and function within the extracellular matrix (ECM), specifically, their interaction with glycosaminoglycans (GAGs) during tumor progression. Metals and GAGs have been individually associated with physiological and pathological processes, however, their combined activities in regulating cell behavior and ECM remodeling have not been fully explored to date. During tumor progression, divalent metals and GAGs participate in central processes, such as cell migration and angiogenesis, either by modulating cell surface molecules, as well as soluble signaling factors. In addition, studies on metals and polysaccharides interactions have been of great value, as they provide structural information that can be correlated with function. Finally, we believe that understanding how metals are regulated in physiological and pathological conditions is paramount for the development of new treatment strategies, as well as diagnostic and exploratory tools.

Identification of the novel HLA-C*05:01:49 allele in a Brazilian candidate donor for bone marrow donation.

Identification of the novel HLA-C*05:01:49 allele that differs from HLA-C*05:01:01:02 in exon 4.

Tunicate Heparan Sulfate Enriched in 2-Sulfated ß-Glucuronic Acid: Structure, Anticoagulant Activity, and Inhibitory Effect on the Binding of Human Colon Adenocarcinoma Cells to Immobilized P-Selectin.

Heparin or highly sulfated heparan sulfate (HS) has been described in different invertebrates. In ascidians (Chordata-Tunicata), these glycosaminoglycans occur in intracellular granules of oocyte accessory cells and circulating basophil-like cells, resembling mammalian mast cells and basophils, respectively. HS is also a component of the basement membrane of different ascidian organs. We have analyzed an HS isolated from the internal organs of the ascidian Phallusia nigra, using solution 1H/13C NMR spectroscopy, which allowed us to identify and quantify the monosaccharides found in this glycosaminoglycan. A variety of α-glucosamine units with distinct degrees of sulfation and N-acetylation were revealed. The hexuronic acid units occur both as α-iduronic acid and ß-glucuronic acid, with variable sulfation at the 2-position. A peculiar structural aspect of the tunicate HS is the high content of 2-sulfated ß-glucuronic acid, which accounts for one-third of the total hexuronic acid units. Another distinct aspect of this HS is the occurrence of high content of N-acetylated α-glucosamine units bearing a sulfate group at position 6. The unique ascidian HS is a potent inhibitor of the binding of human colon adenocarcinoma cells to immobilized P-selectin, being 11-fold more potent than mammalian heparin, but almost ineffective as an anticoagulant. Thus, the components of the HS structure required to inhibit coagulation and binding of tumor cells to P-selectin are distinct. Our results also suggest that the regulation of the pathway involved in the biosynthesis of glycosaminoglycans suffered variations during the evolution of chordates.

NH36 and F3 Antigen-Primed Dendritic Cells Show Preserved Migrating Capabilities and CCR7 Expression and F3 Is Effective in Immunotherapy of Visceral Leishmaniasis.

Physical contact between dendritic cells (DCs) and T cell lymphocytes is necessary to trigger the immune cell response. CCL19 and CCL21 chemokines bind to the CCR7 receptor of mature DCs, and of T cells and regulate DCs migration to the white pulp (wp) of the spleen, where they encounter lymphocytes. In visceral leishmaniasis (VL), cellular immunosuppression is mediated by impaired DC migration due to the decreased chemokine secretion by endothelium and to the reduced DCs CCR7 expression. The Leishmania (L.) donovani nucleoside hydrolase NH36 and its C-terminal domain, the F3 peptide are prominent antigens in the generation of preventive immunity to VL. We assessed whether these vaccines could prevent the migrating defect of DCs by restoring the expression of CCR7 receptors. C57Bl6 mice were vaccinated with NH36 and F3 and challenged with L. (L.) infantum chagasi. The F3 vaccine induced a 100% of survival and a long-lasting immune protection with an earlier CD4+Th1 response, with secretion of higher IFN-γ and TNF-α/IL-10 ratios, and higher frequencies of CD4+ T cells secreting IL-2+, TNF-α+, or IFN-γ+, or a combination of two or the three cytokines (IL-2+TNF-α+IFN-γ+). The CD8+ T cell response was promoted earlier by the NH36-vaccine, and later by the F3-vaccine. Maximal number of F3-primed DCs migrated in vitro in response to CCL19 and showed a high expression of CCR7 receptors (26.06%). Anti-CCR7 antibody treatment inhibited DCs migration in vitro (90%) and increased parasite load in vivo. When transferred into 28-day-infected mice, only 8% of DCs from infected, 59% of DCs from NH36-vaccinated, and 84% of DCs from F3-vaccinated mice migrated to the wp. Consequently, immunotherapy of infected mice with F3-primed DCs only, promoted increases in corporal weight and reductions of spleen and liver parasite loads and relative weights. Our findings indicate that vaccination with F3-vaccine preserves the maturation, migration properties and CCR7 expression of DCs, which are essential processes for the generation of cell-mediated immunity. The F3 vaccine is more potent in reversing the migration defect that occurs in VL and, therefore, more efficient in immunotherapy of VL.

The prevalence of HLA alleles in a lupus nephritis population.

BACKGROUND: Systemic lupus erythematosus (SLE) is a severe autoimmune disease that involves multiple organ systems. Lupus nephritis (LN) is a complication of SLE and is associated with poor survival and high morbidity. Many genomic studies have been performed worldwide, and several histocompatibility leukocyte antigen (HLA) loci are linked to lupus susceptibility. OBJECTIVE: The present study evaluated the association of HLA alleles in a lupus patient population, LN group and control group. The second objective evaluated whether HLA allele match or mismatch influenced kidney graft survival in a kidney transplanted lupus population. METHODS: This study was a retrospective study of 2 major groups: general lupus patients (GSLE - n = 108) and a control group (GControl - n = 216). Both groups were also divided into subgroups. RESULTS: The control group was divided into two subgroups: a healthy control group (HeCTRL) and transplant control group (TxCTRL). The GSLE group was composed of transplanted lupus patients (TxSLE) and non-transplanted lupus patients (nTxSLE). Comparison of the demographics between groups did not reveal differences between ethnicity and gender. A difference in the prevalence of three alleles, B*08, DRB1*08 and DRB1*15, was observed. These alleles were more prevalent in the lupus subgroups compared to the control groups. Five-year survival was not different between patients carrying the allele DRB1*15 in either group (overall p = 0.075; TxSLE p = 0.419; TxCTRL = 0.309). The presence of the match with this allele in the receptor was evaluated and did not demonstrate any difference in graft survival in both groups (p = 0.146) or when analyzed separately in each group (TxCTRL p = 0.739; TxSLE = 0.297). CONCLUSION: This study demonstrated that the presence of HLA-DRB1*15 was a strong factor that predisposed patients to the development of SLE and LN, but did not influence kidney graft survival.

Anticoagulant properties of a high molecular weight polysaccharide fraction (1000RS) of the ascidian Microcosmus exasperatus / Propiedades anticoagulantes de una fracción polisacárida de alto peso molecular (1000RS) del ascidian Microcosmus exasperatus

Aims: The anticoagulant effect and cytotoxicity of a high molecular weight polysaccharide fraction (1000RS) obtained from the tunic of the ascidia Microcosmus exasperatus were evaluated. Methods: Anticoagulant properties of 1000RS was evaluated by activated Partial Thromboplastin Time (aPTT), Thrombin Time (TT), Prothrombin Time (PT), anti-factor Xa and lupic anticoagulant (dRVVT) assays. Cytotoxicity was tested on murine hematopoietic cells using MTT assay. Results: This galactose rich fraction showed to be a potential anticoagulant due to its inhibitory effect on the intrinsic coagulation pathway. At the same time, anticoagulant doses of this fraction have no effect on cellular viability, which means that it can be used as a therapeutic agent. Conclusion: In vitro anticoagulant effect of 1000RS occurs at innocuous doses, however, it still need to be tested using in vivo models and its cytotoxicity evaluated in normal human cell lines

Objetivos: El efecto anticoagulante y la citotoxicidad de una fracción de polisacáridos de alto peso molecular (1000RS), obtenida de la túnica de la ascidia Microcosmus exasperatus, fueron evaluados. Métodos: La actividad anticoagulante de 1000RS fue evaluada mediante los ensayos de tiempo de tromboplastina parcial activado (TTPa), tiempo de trombina (TT), tiempo de protrombina (TP), anti factor Xa y anticoagulante lúpico (dRVVT). La citotoxicidad sobre las células hematopoyéticas murinas, fue evaluada usando el método del MTT. Resultados: Esta fracción rica en galactosa mostró ser un anticoagulante potencial debido a su efecto inhibidor de la vía intrínseca de la coagulación. Así mismo, las dosis anticoagulantes de esta fracción no afectan la viabilidad celular, lo cual ratifica su potencial como agente terapéutico. Conclusión: El efecto anticoagulante in vitro de 1000RS ocurre a dosis inocuas, sin embargo, este debe ser evaluado en modelos in vivo, así como su citotoxicidad sobre células humanas normales

Sensitivity of Dendritic Cells to Microenvironment Signals.

Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.