Dysregulated innate lymphocytes in patients with primary antibody deficiency treated with intravenous immunoglobulin

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La energía de activación como marcador de heterogeneidad enzimática: Utilidad en bioquímica clínica / The activation energy as a marker of enzyme heterogeneity: Usefulness in clinical biochemistry

La energía de activación (Ea) puede proporcionar datos de interésen estudios de caracterización de la heterogeneidad enzimática, tantopara sistemas enzimáticos presentando verdaderas isoenzimascomo formas moleculares de origen post-traduccional. En el presenteartículo se hace una revisión bibliográfica de los datos previamentepublicados para distintas enzimas de utilidad diagnóstica, comocreatina kinasa, α-amilasa, lactato deshidrogenasa, aspartato-aminotransferasa,fosfatasa alcalina, γ-glutamiltransferasa, 5’-nucleotidasa,alanino aminopeptidasa y β-N-acetilhexosaminidasa. Asimismo, se sugierenposibles líneas de investigación, en las que esta variable termodinámicapodría proporcionar datos interesantes para otras enzimascon aplicación clínica(AU)

The energy of activation (Ea) may provide interesting data in the studiesof enzyme heterogeneity characterization, both for enzyme systemshaving true isoenzymes or molecular forms with a post-transcriptionalsource. In this article a bibliographical review is carried out on the previouslypublished results for several enzymes with diagnostic usefulness,as the creatine kinase, α-amylase, lactate dehydrogenase, aspartate aminotransferase,alkaline phosphatase, γ-glutamyltransferase, 5´-nucleotidase,alanine aminopeptidase, and β-N-acetylhexosaminidase. Likewise,possible investigation lines are suggested, in which this thermodynamicvariable would to give interesting data for other enzymes with clinicalusefulness(AU)

The renaissance of T regulatory cells: looking for markers in a haystack

Un tema básico en la Inmunología es cómo el Sistema Inmunitariopuede proteger al huésped frente a una extraordinaria variedadde organismos patógenos al mismo tiempo que controla esasrespuestas para que su duración o intensidad no sean perjudicialespara el organismo. Desde hace varios años se han acumuladolos datos que subrayan la importancia de linfocitos T diferenciadosen el timo, denominados linfocitos T reguladores (Treg), enla supresión de las respuestas inmunitarias normales y patológicas,contribuyendo a la tolerancia a los elementos propios y a lahomeostasis inmune. Su papel en el control de la respuesta inmunitariafrente a tumores, alergenos, patógenos e injertos alogeneicosha llamado la atención hacia su potencial uso terapéutico. Sinembargo, para que este potencial pueda convertirse en realidad esprecisa una buena caracterización fenotípica y funcional de estasubpoblación, una tarea que se ha comprobado dificultosa. Así,todavía no están claros muchos puntos acerca de los genes diferenciadoresmaestros de este linaje celular, sus marcadores de superficieespecíficos, o sus mecanismos de supresión.En dos trabajos muy recientes se han descrito las nucleotidasasCD39 y CD73 como marcadores de superficie de las célulasTreg, lo que permite unir la actividad supresora de estas célulascon modelos previos de inmunosupresión en los cuales la adenosinay el AMP cíclico tenían un papel funcional primordial

A key issue in Immunology is how the Immune System managesto achieve its major aim of protecting the host against an extraordinaryvariety of pathogens while, at the same time, controllingresponses whose perduration and intensity might be harmful tothe organism. For some years now, evidence has come out ofthe importance of a thymus-derived T cell subpopulation, called“regulatory” (Treg), able of suppressing physiological and pathologicalresponses, contributing to self tolerance and immunehomeostasis. Its role in controlling immune response to tumours,allergens, pathogens and allogeneic grafts has driven the attentiontowards its therapeutic potential. However, to develop thistherapeutic potential to the full a good phenotypical and functionalcharacterization of this subpopulation is necessary, a taskthat has proven difficult. Thus, many factors still remain obscureconcerning the master differentiation genes of these cells, thespecificity of their surface markers, or their suppressor mechanisms.In two recent papers, the nucleotidases CD39 and CD73 havebeen described as T regulatory cell surface markers, linking thesuppressive activity of these cells with previous immunosuppressormodels in which adenosine and cAMP had functionalrelevance for cellular immunoregulation

Immunogold labeling and cerium cytochemistry of the enzyme ecto-5'-nucleotidase in promastigote forms of Leishmania species

We have applied both enzyme cytochemistry and immunological labeling techniques to characterize the enzyme 5'-nucleotidase (5'-Nase), at the ultrastructural level, in promastigote forms of four Leishmania species: Leishmania amazonensis, Leishmania mexicana, Leishmania donovani and Leishmania chagasi. The cerium phosphate staining was localized at the surface of the cell body, the flagellum and the flagellar pocket membranes of all the parasites studied. The immunogold labelling technique confirmed these results. In this report we localized 5'-Nase in L. chagasi and L. amazonensis which have been implicated respectively in visceral and cutaneous forms of leishmaniasis. In addition, we confirmed the localization of this phosphomonoesterase in the other two species studied. The superior quality of the images, obtained with both methodologies, confirms that these parasites possess mechanisms capable of hydrolyzing nucleotide monophosphates, and that the expression of 5'-Nase is associated with the outer surface of the plasma membrane