A trivalent TNF-R2 as a new tumor necrosis factor alpha-blocking molecule.

The neutralization of tumor necrosis factor alpha (TNFα) with biopharmaceuticals is a successful therapy for inflammatory diseases. Currently, one of the main TNFα-antagonists is Etanercept, a dimeric TNF-R2 ectodomain. Considering that TNFα and its receptors are homotrimers, we proposed that a trimeric TNF-R2 ectodomain could be an innovative TNFα-antagonist. Here, the 3cTNFR2 protein was designed by the fusion of the TNF-R2 ectodomain with the collagen XV trimerization domain. 3cTNFR2 was produced in HEK293 cells and purified by immobilized metal affinity chromatography. Monomers, dimers, and trimers of 3cTNFR2 were detected. The interaction 3cTNFR2-TNFα was assessed. By microscale thermophoresis, the KD value for the interaction was 4.17 ± 0.88 nM, and complexes with different molecular weights were detected by size exclusion chromatography-high performance liquid chromatography. Moreover, 3cTNFR2 neutralized the TNFα-induced cytotoxicity totally in vitro. Although more studies are required to evaluate the anti-inflammatory effect, the results suggest that 3cTNFR2 could be a TNFα-antagonist agent.

Association of antibody titers and 5-HTTLPR gene polymorphisms in pediatric autoimmune neuropsychiatric disorder associated with streptococci / Asociación de títulos de anticuerpos y polimorfismos del gen 5-HTTLPR en trastornos pediátricos neuropsiquiátricos autoinmunes asociados con estreptococo

Abstract Introduction It has been hypothesized that pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS) etiology results from an abnormal immune response to streptococcal infection. There is evidence that the serotonergic system is involved in both obsessive-compulsive disorder (OCD) physiopathology and immunological processes. In the 5' promoter region of 5-HTT, gene encoding for the serotonin transporter we can find the 5-HTTLPR polymorphism that has been associated with OCD. Being PANDAS a disorder with OCD symptoms and likely immune abnormalities, 5-HTT polymorphisms may be particularly relevant for this disorder. Objective This study aimed to test the association between the 5-HT genotypes and the presence of serum antibodies in patients with PANDAS. Method We compared the genotype frequencies and serum anti-streptococcal, anti-neural, and anti-enolase antibodies titers between 56 patients with PANDAS and 20 healthy controls from Mexico and Cuba. Results Antibody titers were higher (anti-enolase, anti-streptococcal) in PANDAS patients compared to healthy controls. No differences in anti-neural antibody levels between both groups were detected. The anti-enolase and anti-neural antibody titer increased according to the polymorphism of the PANDAS patients as follows: LL >SL >SS. Discussion and conclusion This is the first study evaluating the association between the 5-HTTLPR genotypes and antibody titers in PANDAS patients. Associations between polymorphisms in serotonergic genes and immune response could provide valuable information about the interaction between both systems. Our results suggest an association between the S allele and elevated antibody levels in PANDAS patients.

Resumen Introducción Se ha hipotetizado que el trastorno pediátrico neuropsiquiátrico autoinmune asociado a estreptococo (PANDAS) es resultado de una respuesta inmune anormal a una infección estreptocócica. Existe evidencia de que el sistema serotoninérgico está involucrado tanto en la fisiopatología del trastorno obsesivo compulsivo (TOC) como en procesos inmunológicos. En la región promotora de 5-HTT, gen que codifica el transportador de serotonina, podemos encontrar el polimorfismo 5-HTTLPR que se ha asociado con el TOC. Siendo PANDAS un trastorno con síntomas de TOC y probables anormalidades inmunes, los polimorfismos de 5-HTT pueden ser relevantes en este trastorno. Objetivo Evaluar la asociación entre los genotipos de 5-HT y la presencia de anticuerpos séricos en pacientes con PANDAS. Método Comparamos la frecuencia de genotipos de 5-HT y los títulos de anticuerpos anti-estreptococo, antineurales y antienolasa en suero de 56 pacientes con PANDAS y 20 controles sanos de México y Cuba. Resultados Los títulos de anticuerpos antienolasa y antiestreptococo fueron mayores en pacientes con PANDAS en comparación con los controles. El título de anticuerpos antienolasa y antineural aumentó de acuerdo con el polimorfismo de los pacientes con PANDAS de la siguiente manera: LL >SL >SS. Discusión y conclusión Éste es el primer estudio que evalúa la asociación entre los genotipos de 5-HTTLPR y anticuerpos en pacientes con PANDAS. Las asociaciones entre polimorfismos de genes serotoninérgicos y la respuesta inmune podrían proporcionar información sobre la interacción entre ambos sistemas. Nuestros resultados sugieren una asociación entre el alelo S y niveles altos de anticuerpos en pacientes con PANDAS.

Cost-effective procedure for Streptococcus pyogenes immobilized DNA preparation and miniPFGE subtyping.

INTRODUCTION: Group A streptococci (GAS) is responsible of several human diseases ranging from mild infection to severe invasive toxin-mediated disease and post-infectious sequelae. Accordingly, a GAS surveillance program based on molecular techniques is advisable for its epidemiological control. Pulsed-field gel electrophoresis (PFGE) is the gold standard for GAS molecular subtyping, but a major disadvantage is the length of the procedure, which takes 1-3 days of work, minimum. The aim of this study was to develop a rapid and cost-effective procedure for PFGE subtyping of GAS isolates. METHODOLOGY: Different incubation times of GAS, immobilized in agarose miniplugs, in solutions containing lysozyme and/or mutanolysine followed by solutions with urea instead of proteinase K, were assayed. DNA was restricted with SmaI and the fingerprints were obtained in clamped homogeneous electric field (CHEF) chambers and minichambers. The modified procedure was used to subtype 22 GAS isolates. RESULTS: Intact DNA molecules of GAS immobilized in agarose miniplugs were prepared incubating the cells, in situ, with a solution containing lysozyme for 4 hours, followed by the incubation in a non-enzymatic solution with urea for 2 hours. SmaIDNA macrorestriction fragments were well resolved in 5 hours and 14 minutes by electrophoresis in a CHEF minichamber at 10 V/cm. This procedure for GAS DNA preparation was useful for fingerprinting GAS strains in the format of CHEF Mapper (BioRad). CONCLUSIONS: The procedure took 13 hours for GAS strains subtyping. Both sample preparation and electrophoresis in CHEF minichamber represent an economic alternative for performing massive epidemiological studies of this human pathogen.

Detection of anti-streptococcal, antienolase, and anti-neural antibodies in subjects with early-onset psychiatric disorders.

INTRODUCTION: Infection with group A Streptococcus (StrepA) can cause post-infectious sequelae, including a spectrum of childhood-onset obsessive-compulsive (OCD) and tic disorders with autoimmune origin (PANDAS, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections). Until now, no single immunological test has been designed that unequivocally diagnoses these disorders. In this study, we assessed the detection of serum antibodies against human brain enolase (AE), neural tissue (AN) and Streptococcus (AS) as a laboratory tool for the diagnosis of early-onset psychiatric disorders. METHODOLOGY: Serum antibodies against human brain enolase, total brain proteins, and total proteins from StrepA were detected by ELISA in 37 patients with a presumptive diagnosis of PANDAS and in 12 healthy subjects from Mexico and Cuba. RESULTS: The antibody titers against human brain enolase (AE) and Streptococcal proteins (AS) were higher in patients than in control subjects (t-student, tAE=-2.17, P=0.035; tAS=-2.68, P=0.01, n=12 and 37/group, df=47, significance level 0.05), while the neural antibody titers did not differ between the two groups (P(t)=0.05). The number of subjects (titers> meancontrol + CI95) with simultaneous seropositivity to all three antibodies was higher in the patient group (51.4%) than in the control group (8.3%) group (X2=5.27, P=0.022, df=1, n=49). CONCLUSIONS: The simultaneous detection of all three of these antibodies could provide valuable information for the etiologic diagnosis of individuals with early-onset obsessive-compulsive disorders associated with streptococcal infection and, consequently, for prescribing suitable therapy.