Association of class II HLA alleles with susceptibility to develop immune-mediated diseases in Paraguayan patients.

Genetic and nongenetic factors are involved in the pathogenesis of immune-mediated inflammatory diseases (IMIDs). The best-known genetic factor for susceptibility to IMIDs is the human leukocyte antigen (HLA). The aim of the present study was to evaluate the association of HLA class II genes with the risk of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) in the Paraguayan population. We included 254 patients with IMIDs (101 SLE, 103 RA, and 50 SSc) and 50 healthy controls. The haplotypes of five genes corresponding to HLA class II genes and their relationship to the IMIDs studied were determined. Note that 84.6% were women, with a mean age of 43.4 ± 14 years. Among the associated HLA alleles, we found the previously identified risk factors in other populations like HLA-DRB1*03:01 and HLA-DRB1*14:02 for RA, as well as new ones not previously identified, such as DPA1*02:01 for SLE and, DB1*02:01 for RA and SSc. In the genetic association analysis, already known associations have been replicated, and unpublished associations have been identified in Paraguayan patients with IMIDs. This is the first genetic association study in Paraguayan patients with IMIDs.

Screening of Natural Products Inhibitors of SARS-CoV-2 Entry.

The COVID-19 pandemic has led to the search for new molecules with antiviral activity against SARS-CoV-2. The entry of the virus into the cell is one of the main targets for inhibiting SARS-CoV-2 infection. Natural products are an important source of new therapeutic alternatives against diseases. Pseudotyped viruses allow the study of SARS-CoV-2 viral entry inhibitors, and due to their simplicity, they allow the screening of a large number of antiviral candidates in Biosafety Level 2 facilities. We used pseudotyped HIV-1 with the D614G SARS-CoV-2 spike glycoprotein to test its ability to infect ACE2-expressing HEK 293T cells in the presence of diverse natural products, including 21 plant extracts, 7 essential oils, and 13 compounds from plants and fungi. The 50% cytotoxic concentration (CC50) was evaluated using the resazurin method. From these analyses, we determined the inhibitory activity of the extract of Stachytarpheta cayennensis, which had a half-maximal inhibitory concentration (IC50) of 91.65 µg/mL, a CC50 of 693.5 µg/mL, and a selectivity index (SI) of 7.57, indicating its potential use as an inhibitor of SARS-CoV-2 entry. Moreover, our work indicates the usefulness of the pseudotyped-virus system in the screening of SARS-CoV-2 entry inhibitors.

Relationship between serum lipopolysaccharide binding protein levels, disease activity, and clinical characteristics in Paraguayan patients with systemic lupus erythematosus.

INTRODUCTION: Systemic exposure to bacterial components like lipopolysaccharide (LPS) is among the non-genetic factors that could be involved in the onset or progression of systemic lupus erythematosus (SLE). Lipopolysaccharide-binding protein (LBP) participates in the recognition of LPS and in the inflammatory response. Here, we investigated LBP in SLE patients and its relationship with disease activity and SLE phenotypes. METHODS: Eighty-one adult patients with SLE from IMID-PY biobank (Paraguay) were included in the study. The clinical and laboratory variables were used to determine SLE activity. LBP levels were determined by ELISA in SLE patients and age- and sex-matched population-based controls. RESULTS: Patients with SLE have lower levels of circulating LBP compared to healthy controls (p = 0.0007). No significant correlation was found between serum LBP levels and disease activity. A significant difference was observed in LBP levels with regard to the presence of arthritis (p = 0.026). No other relation was found with clinical parameters. CONCLUSIONS: We found low levels of LBP in SLE patients compared to the control group. No correlation was detected between LBP levels and disease activity. It would be interesting for future studies to evaluate the impact of low levels of LBP on lupus immunopathogenesis.

Effect of gluten-free diet on levels of soluble CD14 and lipopolysaccharide-binding protein in adult patients with celiac disease.

INTRODUCTION: Celiac disease (CD) is an autoimmune enteropathy triggered by gluten ingestion in genetically susceptible individuals. In CD, activation of the immune response causes damage of the intestinal mucosa, and a gluten-free diet (GFD) is the only available therapy. Intestinal damage can lead to an increase in the circulation of components of bacteria from the intestinal lumen, such as lipopolysaccharide (LPS). Soluble CD14 (sCD14) and lipopolysaccharide-binding protein (LBP) participate in the recognition of LPS, and their levels are altered in different pathologies. In the present study, the circulating levels of sCD14 and LBP from untreated CD patients were evaluated and compared to CD patients on a GFD and controls. MATERIAL AND METHODS: In total seventy-two adult patients with CD, twenty-three untreated CD patients and forty-nine on a GFD were included. In addition, fifty-five healthy individuals were included as controls. Additionally, the effect of LPS on sCD14 production by both normal and inflamed intestinal tissue culture was explored. RESULTS: Serum levels of sCD14 were found to be significantly increased in untreated CD patients compared to patients on a GFD and controls. In addition, we found that LPS induced the production of sCD14 by biopsies of intestinal tissue from untreated CD patients. CONCLUSIONS: The data from this study show that circulating levels of sCD14 are increased in the untreated CD patients compared to patients on a GFD. Our data show that LPS induces the production of sCD14 by the intestinal tissue from untreated CD patients.

[Anti-transglutaminase antibody in adults with celiac disease and their relation to the presence and duration of gluten-free diet]. / Anticuerpo anti-transglutaminasa tisular en adultos con enfermedad celíaca y su relación con la presencia y duración de la dieta libre de gluten.

IgA anti-transglutaminase 2 (tTG2) antibody is a relevant marker in celiac disease. The utility of IgA anti-tTG2 determination is well established for the diagnosis, however their use in the follow-up of patients with gluten free diet (GFD) it is not fully established. OBJECTIVE: To determine IgA anti-tTG2 antibody levels in adult Paraguayan celiac disease patients and its relation to the presence and duration of the GFD. MATERIALS AND METHODS: Adult celiac disease patients without (n=23) or with (n=49) GFD were included in this observational, descriptive, cross-sectional study with analytical component. IgA anti-tTG2 antibody serum levels were analyzed by ELISA. RESULTS: All (100%) celiac disease patients without GFD had positive anti-tTG2 IgA. Serum levels of IgA anti-tTG2 were significantly elevated in celiac disease patients without GFD compared to levels in patients with GFD. 35% of patients treated with GFD (diet average duration = 5.7 years) had positive (29%) or indeterminate (6%) levels of IgA anti-tTG2. In terms of GFD duration we observed that while the GFD period increased, antibody levels decreased (r=- 0.2963; p=0.0387). CONCLUSION: IgA anti-tTG2 antibody levels correlated inversely with the GFD duration. However, positive levels of these antibodies persisted in some patients, even several years after the onset of GFD.

Characterization of Dengue Virus 4 Cases in Paraguay, 2019-2020.

In 2019-2020, dengue virus (DENV) type 4 emerged to cause the largest DENV outbreak in Paraguay's history. This study sought to characterize dengue relative to other acute illness cases and use phylogenetic analysis to understand the outbreak's origin. Individuals with an acute illness (≤7 days) were enrolled and tested for DENV nonstructural protein 1 (NS1) and viral RNA by real-time RT-PCR. Near-complete genome sequences were obtained from 62 DENV-4 positive samples. From January 2019 to March 2020, 799 participants were enrolled: 253 dengue (14 severe dengue, 5.5%) and 546 other acute illness cases. DENV-4 was detected in 238 dengue cases (94.1%). NS1 detection by rapid test was 52.5% sensitive (53/101) and 96.5% specific (387/401) for dengue compared to rRT-PCR. DENV-4 sequences were grouped into two clades within genotype II. No clustering was observed based on dengue severity, location, or date. Sequences obtained here were most closely related to 2018 DENV-4 sequences from Paraguay, followed by a 2013 sequence from southern Brazil. DENV-4 can result in large outbreaks, including severe cases, and is poorly detected with available rapid diagnostics. Outbreak strains seem to have been circulating in Paraguay and Brazil prior to 2018, highlighting the importance of sustained DENV genomic surveillance.

Neutralizing antibodies from naturally infected individuals against SARS-CoV-2 Gamma and Delta variants in the Paraguayan population.

INTRODUCTION: Severe Acute Respiratory Syndrome-Coronavirus-2 Virus (SARS-CoV-2) is responsible for Coronavirus Disease 2019 (COVID-19). A substantial number of SARS-CoV-2 infection cases have been reported during the pandemic, and vaccination coverage in some regions, particularly in developing countries, remains very low. SARS-CoV-2 variants of concern (VOCs) have also emerged as some of the most pressing public health issues. In this scenario, it is crucial to know whether COVID-19 convalescent antibodies have cross-neutralizing action against VOCs to contribute to the analysis of the future progress of the pandemic. METHODOLOGY: The plasma of individuals infected with SARS-CoV-2 from June to November 2020 in Paraguay (before the first recorded infections associated with VOCs in the country) was selected. Anti-spike antibodies were determined in plasma samples (n = 626) obtained from this convalescent and unvaccinated group. Using a pseudotyped virus neutralization assay, we then investigated the neutralizing response against D614G variant and Gamma, and Delta VOCs. RESULTS: IgG antibodies against spike were detected in 85.6% of convalescent individuals. Samples from individuals previously infected by a non-VOC showed a 6.6- and 8.1-fold reduction in neutralizing capacity to the Gamma and Delta variants, respectively, when compared to the D614G variant. CONCLUSIONS: Our findings show that antibodies generated by non-VOC infection have reduced neutralizing capabilities against Gamma and Delta variants that appeared subsequently and might have implications for immunity strategies.

Serum biomarkers and anti-flavivirus antibodies at presentation as indicators of severe dengue.

BACKGROUND: Dengue is the most common vector-borne viral disease worldwide. Most cases are mild, but some evolve into severe dengue (SD), with high lethality. Therefore, it is important to identify biomarkers of severe disease to improve outcomes and judiciously utilize resources. METHODS/PRINCIPAL FINDINGS: One hundred forty-five confirmed dengue cases (median age, 42; range <1-91 years), enrolled from February 2018 to March 2020, were selected from an ongoing study of suspected arboviral infections in metropolitan Asunción, Paraguay. Cases included dengue virus types 1, 2, and 4, and severity was categorized according to the 2009 World Health Organization guidelines. Testing for anti-dengue virus IgM and IgG and serum biomarkers (lipopolysaccharide binding protein and chymase) was performed on acute-phase sera in plate-based ELISAs; in addition, a multiplex ELISA platform was used to measure anti-dengue virus and anti-Zika virus IgM and IgG. Complete blood counts and chemistries were performed at the discretion of the care team. Age, gender, and pre-existing comorbidities were associated with SD vs. dengue with/without warning signs in logistic regression with odds ratios (ORs) of 1.07 (per year; 95% confidence interval, 1.03, 1.11), 0.20 (female; 0.05,0.77), and 2.09 (presence; 1.26, 3.48) respectively. In binary logistic regression, for every unit increase in anti-DENV IgG in the multiplex platform, odds of SD increased by 2.54 (1.19-5.42). Platelet count, lymphocyte percent, and elevated chymase were associated with SD in a combined logistic regression model with ORs of 0.99 (1,000/µL; 0.98,0.999), 0.92 (%; 0.86,0.98), and 1.17 (mg/mL; 1.03,1.33) respectively. CONCLUSIONS: Multiple, readily available factors were associated with SD in this population. These findings will aid in the early detection of potentially severe dengue cases and inform the development of new prognostics for use in acute-phase and serial samples from dengue cases.

Screening of medicinal plants from El Salvador for anti-viral activity against Herpes simplex 1.

Herpes simplex virus 1 is one of the most prevalent pathogens worldwide. Resistant strains to current anti-viral treatment have been reported, requiring the search for novel anti-virals. Using a qPCR method to assess anti-herpetic activity from natural products, we analyzed 72 plant extracts from El Salvador and identified eighteen methanolic extracts with anti-viral activity of ≥ 75%. Anti-herpetic activity has not been previously reported in fourteen of the plants (Euphorbia lancifolia, Piper tuberculatum, Cordia alliodora, Tecoma stans, Taraxacum officinale, Hamelia patens, Witheringia solanacea, Emilia fosbergii, Gnaphalium viscosum, Citrus aurantium, Ambrosia peruviana, Carica papaya, Solanum hazenii and Melothria pendula). Four extracts were from species with previously reported anti-herpetic activity (Plantago major, Psidium guajava, Sida acuta and Bursera simaruba). These extracts effective anti-viral concentrations (EC50) were between 203 and 6.31 µg/mL, while the selectivity indexes (SI) were between 55.91 and 2.57. Euphorbia lancifolia showed the most effective anti-viral activity (EC50 = 6.31 µg/mL, SI = 51.82).

Phosphatidylinositol 3-kinase interacts with the glucocorticoid receptor upon TLR2 activation.

Airway inflammation is a common condition where glucocorticoids (GC) are a well-established therapy. It has been demonstrated that GC stimulate components of innate immunity. Specifically, GC up-regulate TLR2 expression and activation upon inflammatory stimuli; however, little is known about the signalling involved in this process. To determine the mechanism by which dexamethasone modulates TLR2-induced cytokine production this signalling pathway was monitored in a lung epithelial cell line exposed to the TLR2 synthetic agonist, Pam(3) -Cys-Ser-Lys(4) . These experiments demonstrate that phosphatidylinositol 3-kinase (PI3K) is critical for the TLR2 downstream effects of GC. Cells expressing a PI3K mutant (p85-dominant negative, DN; p85 Δ478-511) and exposed to Pam(3) -Cys-Ser-Lys(4) in the presence or absence of dexamethasone, showed enhanced tumour necrosis factor (TNF)α expression while AP-1 and NF-κB transcriptional activity were repressed. We provide experimental evidence that PI3K physically interacts with the glucocorticoid receptor (GR) through two putative PI3K recruitment consensus YxxM binding motifs in the GR, suggesting that some functions regulated by this receptor might occur through kinase interaction. Mutations of two tyrosine residues in the GR, 598 and 663, to phenylalanine significantly reduced interaction with PI3K and the GC effects on TLR2-induced TNF-α expression. However, these mutations did not alter GR transcriptional activity nor affect cellular localization of the expressed mutant GR in COS-1 cells. Therefore, the PI3K-GR interaction may contribute to the effects of GC on the TLR2 pro-inflammatory signalling cascade, thus defining a novel signalling mechanism with a profound impact on innate immune responses.

Vacunas contra el virus chikungunya: avances y perspectivas

El virus chikungunya (CHIKV) es un alfavirus cuya infección provoca una enfermedad caracterizada principalmente por fiebre y dolores articulares/musculares. Entre 25-50% de las infecciones se presentan con enfermedad crónica que puede durar de meses a años. El primer brote de CHIKV en Paraguay corresponde al año 2015, siendo el último en el año 2022/2023. Diversos candidatos vacunales contra CHIKV se encuentran en diferentes etapas de desarrollo, e incluso recientemente (noviembre/2023) fue aprobada la primera vacuna contra CHIKV llamada VLA1553 (Ixchiq). Adicionalmente, al menos 30 candidatos vacunales se encuentran en ensayos preclínicos/clínicos. Con la aprobación de la primera vacuna contra CHIKV y la posibilidad de otras que lleguen al mercado prontamente, debido al estado avanzado de otros candidatos vacunales, se abrirá un nuevo escenario en esta enfermedad. Se espera que la introducción de vacunas efectivas genere un avance importante para la prevención de esta enfermedad, disminuyendo los casos agudos y los efectos crónicos de la infección por el virus. En este trabajo de revisión se analiza el avance de las vacunas contra CHIKV, además de examinar los desafíos de vigilancia epidemiológica que plantean la introducción de estas vacunas.

Chikungunya virus (CHIKV) is an alphavirus that causes an illness characterized mainly by fever and joint/muscle pain. Between 25-50% of infections present with chronic diseases that can last from months to years. The first outbreak of CHIKV in Paraguay occurred in 2015, with the last outbreak occurring in 2022/2023. Several vaccine candidates against CHIKV are in different stages of development, and even recently (November/2023), the first vaccine against CHIKV, called VLA1553 (Ixchiq), was approved. In addition, at least 30 vaccine candidates are available for preclinical and clinical trials. With the approval of the first vaccine against CHIKV and the possibility of others coming to the market soon, due to the advanced status of other vaccine candidates, a new scenario will open for this disease. The introduction of effective vaccines is expected to generate an important advance in the prevention of this disease, reducing acute cases and the chronic effects of viral infection. This review analyzes the progress of CHIKV vaccines and examines the epidemiological surveillance challenges posed by the introduction of these vaccines.

Metalloproteinase-dependent TLR2 ectodomain shedding is involved in soluble toll-like receptor 2 (sTLR2) production.

Toll-like receptor (TLR) 2, a type I membrane receptor that plays a key role in innate immunity, recognizes conserved molecules in pathogens, and triggering an inflammatory response. It has been associated with inflammatory and autoimmune diseases. Soluble TLR2 (sTLR2) variants have been identified in human body fluids, and the TLR2 ectodomain can negatively regulate TLR2 activation by behaving as a decoy receptor. sTLR2 generation does not involve alternative splicing mechanisms, indicating that this process might involve a post-translational modification of the full-length receptor; however, the specific mechanism has not been studied. Using CD14+ peripheral human monocytes and the THP-1 monocytic leukemia-derived cell line, we confirm that sTLR2 generation increases upon treatment with pro-inflammatory agents and requires a post-translational mechanism. We also find that the constitutive and ligand-induced release of sTLR2 is sensitive to pharmacological metalloproteinase activator and inhibitors leading us to conclude that metalloproteinase TLR2 shedding contributes to soluble receptor production. By expressing human TLR2 in ADAM10- or ADAM17-deficient MEF cells, we find both enzymes to be implicated in TLR2 ectodomain shedding. Moreover, using a deletion mutant of the TLR2 juxtamembrane region, we demonstrate that this domain is required for sTLR2 generation. Functional analysis suggests that sTLR2 generated by metalloproteinase activation inhibitsTLR2-induced cytokine production by this monocytic leukemia-derived cell line. The identification of the mechanisms involved in regulating the availability of soluble TLR2 ectodomain and cell surface receptors may contribute further research on TLR2-mediated processes in innate immunity and inflammatory disorders.

Niveles de IgA en adultos con enfermedad celíaca / IgA levels in adults with celiac disease

La enfermedad celíaca (EC) es una enfermedad autoinmune sistémica desencadenada por el consumo de gluten de la dieta en personas con susceptibilidad genética. Los principales test serológicos utilizados para el diagnóstico y seguimiento de la EC son pruebas basadas en anticuerpos de isotipo inmunoglobulina (Ig) A, siendo la determinación de IgA anti-transglutaminasa tisular (tTG)2 la prueba serológica inicial de elección. La deficiencia selectiva de IgA (DSIgA), es más prevalente en pacientes con EC que en la población general, dificultando el diagnostico serológico de la enfermedad. En el presente estudio observacional descriptivo, se incluyeron 74 pacientes adultos con diagnóstico confirmado de EC y se determinó IgA anti-tTG2 en suero mediante ensayo de ELISA a fin de detectar a aquellos pacientes con niveles indeterminados o negativos, los cuales podrían presentar DSIgA. Se dosó IgA total en el suero de estos pacientes por inmunodifusión radial y el promedio fue de 237,8 ± 100,6 mg/dL. En una paciente del sexo femenino fue detectada IgA total menor a 7 mg/dL, con niveles séricos de IgG e IgM normales, característicos de la DSIgA. Así, la frecuencia calculada de DSIgA fue de 1,35% en la población con EC estudiada. En conclusión, este trabajo es una primera aproximación para describir la frecuencia de DSIgA en pacientes con EC del país y reafirma la importancia de incluir el dosaje de IgA total en el caso de realizar test serológicos de la EC basados en IgA(AU)

Anticuerpo anti-transglutaminasa tisular en adultos con enfermedad celíaca y su relación con la presencia y duración de la dieta libre de gluten / Anti-transglutaminase antibody in adults with celiac disease and their relation to the presence and duration of gluten-free diet

Introducción: El anticuerpo IgA anti-transglutaminasa tisular 2 (tTG2) es un marcador relevante de la enfermedad celíaca. La utilidad de la determinación de IgA anti-tTG2 está bien establecida para el diagnóstico de la patología, sin embargo su uso para el seguimiento de pacientes con dieta libre de gluten (DLG) no se encuentra del todo esclarecido. Objetivo: Determinar los niveles de IgA anti-tTG2 en pacientes adultos paraguayos con enfermedad celíaca y su relación con la presencia y duración de la DLG. Materiales y métodos: En este estudio observacional descriptivo con componente analítico, transversal, se incluyeron pacientes celíacos adultos, sin (n=23) o con (n=49) DLG. Se determinaron por ELISA los niveles séricos de IgA anti-tTG2. Resultados: Todos (100%) los pacientes celíacos sin DLG presentaron niveles séricos positivos de IgA anti-tTG2. Se observaron niveles séricos de IgA anti-tTG2 significativamente elevados en pacientes celíacos sin DLG en comparación con los niveles en pacientes con DLG. El 35% de los pacientes en tratamiento con DLG (promedio de duración de la dieta = 5,7 años) presentaron niveles positivos (29%) o indeterminados (6%) de IgA anti-tTG2. En relación con la duración de la DLG se observó que al aumentar el tiempo de DLG disminuyen los niveles del auto-anticuerpo (r=-0,2963; p=0,0387). Conclusiones: Los niveles de IgA anti-tTG2 se correlacionaron inversamente con la duración de la DLG. Sin embargo, niveles positivos del anticuerpo persistieron en algunos pacientes, incluso varios años después del inicio de la DLG.

IgA anti-transglutaminase 2 (tTG2) antibody is a relevant marker in celiac disease. The utility of IgA anti-tTG2 determination is well established for the diagnosis, however their use in the follow-up of patients with gluten free diet (GFD) it is not fully established. Objective: To determine IgA anti-tTG2 antibody levels in adult Paraguayan celiac disease patients and its relation to the presence and duration of the GFD. Materials and methods: Adult celiac disease patients without (n=23) or with (n=49) GFD were included in this observational, descriptive, cross-sectional study with analytical component. IgA anti-tTG2 antibody serum levels were analyzed by ELISA. Results: All (100%) celiac disease patients without GFD had positive anti-tTG2 IgA. Serum levels of IgA anti-tTG2 were significantly elevated in celiac disease patients without GFD compared to levels in patients with GFD. 35% of patients treated with GFD (diet average duration = 5.7 years) had positive (29%) or indeterminate (6%) levels of IgA anti-tTG2. In terms of GFD duration we observed that while the GFD period increased, antibody levels decreased (r=0.2963; p=0.0387). Conclusion: IgA anti-tTG2 antibody levels correlated inversely with the GFD duration. However, positive levels of these antibodies persisted in some patients, even several years after the onset of GFD.

Extractos vegetales de tres especies del género Baccharis inducen la proliferación de células mononucleares humanas / Plant extracts of three species of the genus Baccharis induce human mononuclear cells proliferation

Las plantas de uso en medicina tradicional constituyen una fuente importante de compuestos con actividad inmunomoduladora; entre ellas las especies del género Baccharis, conocidas popularmente como "Jaguareteka´a" en nuestro país, son ampliamente empleadas. En este estudio se evaluó la actividad inmunomoduladora de extractos metanólicos de tres especies del género Baccharis (B. trimera, B. notosergilay B. punctulata) sobre la proliferación de células mononucleares humanas de sangre periférica. Los extractos de las tres especies estudiadas estimularon la proliferación de las células mononucleares. Específicamente, el extracto de B. notosergila estimuló la proliferación celular a todas las concentraciones probadas (5, 10, 25 y 50 µg/mL), mientras que los extractos de B. trimera y B. punctulata mostraron este efecto a 5 y 10 µg/mL. Además, por presentar mayor inducción de la proliferación, se realizó un fraccionamiento con diferentes solventes del extracto metanólico de B. notosergila y B. punctulata. La fracción de acetato de etilo de ambos extractos vegetales aumentó la proliferación celular, sugiriendo que compuestos de polaridad media son los responsables de esta actividad. Estos resultados demuestran que los extractos de B. trimera, B. notosergila y B. punctulata poseen actividad inmunomoduladora sobre células mononucleares humanas y servirán de base a otros estudios para determinar el o los componentes activos de los extractos sobre el sistema inmune(AU)

Plants used in traditional medicine are an important source of compounds with immunomodulatory activity. Species of the genus Baccharis, popularly known as "Jaguareteka'a" in our country, are used in folk medicine for the treatment of liver, gastrointestinal, inflammatory and infectious diseases. In this study, we evaluated the immunomodulatory activity of methanolic extracts of three species of the genus Baccharis (B. trimera, B. notosergila and B. punctulata) on the proliferation of human peripheral blood mononuclear cells. Extracts of the three species studied stimulated the proliferation of mononuclear cells. The extract of B. notosergila stimulated cell proliferation at all concentrations tested, while extracts of B. trimera and B. punctulata stimulated at 5 and 10 µg/mL. In addition, we carried out a separation with different solvents of the methanolic extract of B. notosergila and B. punctulata. The ethyl acetate fraction of both plant extracts induced the proliferation of immune cells. These results show that the extracts of B. trimera, B. notosergila and B. punctulata had immunomodulatory activity on human mononuclear cells. Future work will be required to identify the components responsible for the activity on the immune system(AU)

Increased production of soluble TLR2 by lamina propria mononuclear cells from ulcerative colitis patients.

Toll-like receptor 2 (TLR2) is a type I pattern recognition receptor that has been shown to participate in intestinal homeostasis. Its increased expression in the lamina propria has been associated with the pathogenesis in inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn's disease (CD). Recently, soluble TLR2 (sTLR2) variants have been shown to counteract inflammatory responses driven by the cognate receptor. Despite the evident roles of TLR2 in intestinal immunity, no study has elucidated the production and cellular source of sTLR2 in IBD. Furthermore, an increase in the population of activated macrophages expressing TLR2 that infiltrates the intestine in IBD has been reported. We aimed first to assess the production of the sTLR2 by UC and CD organ culture biopsies and lamina propria mononuclear cells (LPMCs) as well as the levels of sTLR2 in serum, and then characterize the cell population from lamina propria producing the soluble protein. Mucosa explants, LPMCs and serum were obtained from UC, CD patients and control subjects. The level of sTLR2 was higher in conditioned media from organ culture biopsies and LPMCs from UC patients in comparison to CD and controls. Moreover, an inverse correlation between the content of intestinal and serum sTLR2 levels was observed in UC patients. Additionally, when characterizing the cellular source of the increased sTLR2 by LPMCs from UC patients, an increase in TLR2(+)/CD33(+) cell population was found. Also, these cells expressed CX3CR1, which was related to the increased levels of intestinal FKN in UC patients, suggesting that a higher proportion of TLR2(+) mononuclear cells infiltrate the lamina propria. The increased production of sTLR2 suggests that a differential regulating factor of the innate immune system is present in the intestinal mucosa of UC patients.

Presente y futuro de los anticuerpos recombinantes terapéuticos / Present and future of therapeutic recombinant antibodies

Los anticuerpos constituyen un componente fundamental del sistema inmune, permitiendo el reconocimiento con alta especificidad y posterior destrucción de moléculas extrañas. Los anticuerpos monoclonales, producidos por la tecnología del hibridoma, presentan desventajas para su uso en terapia humana debido a su origen en una especie diferente. La ingeniería genética posibilitó la utilización de los anticuerpos monoclonales para terapias humanas, generando los anticuerpos recombinantes terapéuticos. Así, los anticuerpos recombinantes se han transformado en un importante grupo de fármacos; con decenas de ellos aprobados para terapia humana y cientos en desarrollo. Se utilizan con éxito como tratamiento para un amplio rango de patologías, tales como cáncer, autoinmunidad e infecciones, siendo desde hace años el biofármaco con mayores ventas. Inicialmente todos los anticuerpos recombinantes terapéuticos presentaban la estructura convencional de los anticuerpos. Sin embargo, más recientemente, se han generado nuevos diseños que no poseen las características estructurales naturales, como los anticuerpos de simple cadena y bi-específicos. Debido al desarrollo y éxito de la tecnología de anticuerpos recombinantes, se espera un aumento constante en el número de anticuerpos terapéuticos contra nuevos blancos, además de la generación de nuevas estructuras, usos y estrategias terapéuticas. En esta revisión, nos centraremos en las características estructurales y los nuevos formatos de anticuerpos, así como su aplicación clínica en el tratamiento de diversas patologías. Además analizaremos los nuevos formatos de anticuerpos que se encuentran en el mercado y la aparición de los anticuerpos biosimilares.

Antibodies are a key component of the immune system, acting in the highly specific recognition and subsequent destruction of foreign molecules. Monoclonal antibodies produced by hybridoma technology have disadvantages for use in human therapy becauseof its origin in a different species. Genetic engineering enabled the use of monoclonalantibodies for human therapies, generating recombinant therapeutic antibodies. Thus, the recombinant antibodies have become an important group of drugs; dozens of them are approved for human therapy and there are hundreds in development. They are successfully used as a treatment for a wide range of pathologies, such as cancer, autoimmunity and infections, being the biopharmaceutical with higher sales. Initially therapeutic recombinant antibodies showed the conventional structure of the antibodies. However, more recently, new designs that do not have natural structural features havebeen generated such as single chain formats and bi-specific antibodies. Due to development and success of recombinant antibody technology, a steady increase in the number of newtherapeutic drugs against new targets is expected in addition to the generation of new structures, uses and therapeutic strategies. In this review, we will focus on their structural features and clinical application in the treatment of various pathologies. We will also discuss new formats of antibodies and the emergence of biosimilar antibodies.