IL-10 Overexpression After BCG Vaccination Does Not Impair Control of Mycobacterium tuberculosis Infection

Control of tuberculosis depends on the rapid expression of protective CD4+ T-cell responses in the Mycobacterium tuberculosis (Mtb)-infected lungs. We have recently shown that the immunomodulatory cytokine IL-10 acts intrinsically in CD4+ T cells and impairs their parenchymal migratory capacity, thereby preventing control of Mtb infection. Herein, we show that IL-10 overexpression does not impact the protection conferred by the established memory CD4+ T-cell response, as BCG-vaccinated mice overexpressing IL-10 only during Mtb infection display an accelerated, BCG-induced, Ag85b-specific CD4+ T-cell response and control Mtb infection. However, IL-10 inhibits the migration of recently activated ESAT-6-specific CD4+ T cells into the lung parenchyma and impairs the development of ectopic lymphoid structures associated with reduced expression of the chemokine receptors CXCR5 and CCR7. Together, our data support a role for BCG vaccination in preventing the immunosuppressive effects of IL-10 in the fast progression of Mtb infection and may provide valuable insights on the mechanisms contributing to the variable efficacy of BCG vaccination

Caratterizzazione di patologie autoimmuni, quali LES e UCTD, tramite marcatori molecolari di danno ossidativo e genomico.

Caratteristiche peculiari del sistema immunitario sono la capacità di riconoscere e, successivamente, reagire contro gli antigeni estranei (non self) al sistema – al fine di eliminarli e prevenire una possibile infezione – e quella di rimanere inerte di fronte agli antigeni self (molecole prodotte dall’organismo stesso). Quest’ultima abilità viene denominata “tolleranza immunologica”; la sua perdita è connessa a una reattività anomala dei linfociti maturi che reagiscono anche contro i self, provocando l’insorgenza di patologie autoimmunitarie. Questo tipo di malattie presenta una prevalenza del 3-5% nella popolazione generale e solitamente è più frequente nel sesso femminile, con un rapporto femmine:maschi che varia da 10:1 a 2:1. Possono coinvolgere uno specifico organo (autoimmuni organo specifiche) o più organi (autoimmuni sistemiche): di quelle sistemiche hanno suscitato interesse le Connettivi Differenziate o Definite (CTD) e le Connettiviti Indifferenziate (UCTD). Con il primo termine ci si riferisce ad un gruppo di disordini immunitari che vengono classificati come patologie reumatiche sistemiche tra le quali il lupus eritematoso sistemico (LES) e l’artrite reumatoide (AR). Il secondo termine (UCTD), invece, riguarda forme incomplete o iniziali di connettiviti definite che non soddisfano i criteri di classificazione per le CTD ma che potrebbero, con il tempo, diventare tali. Infatti le Connettiviti Indifferenziate potrebbero rimanere stabili per anni, oppure evolvere verso un tipo specifico di Connettivite Definita – frequentemente il LES. Con il presente lavoro ci si è proposti di valutare il danno ossidativo e genomico nei linfociti T di soggetti affetti da lupus eritematoso sistemico e connettiviti indifferenziate. Il campione in studio era costituito da 86 donne di età compresa tra i 20 e 70 anni, suddivisi in tre classi in base alla loro condizione: soggetti sani (utilizzati come controlli), UCTD e LES. I soggetti affetti dalle due connettiviti sono stati ulteriormente suddivisi in base allo stato di attività della malattia e alla presenza o assenza di un profilo autoanticorpale positivo. Il danno ossidativo è stato valutato a livello delle membrane cellulari mediante l’utilizzo di un analogo strutturale dei fosfolipidi di membrana, la sonda C11-BODIPY 581/591, che grazie alle sue proprietà fluorescenti permette, intercalandosi nel doppio strato fosfolipidico, di discriminare le cellule ossidate da quelle sane. Il danno al DNA, invece, è stato caratterizzato attraverso l’analisi dei foci γH2AX: grazie a questo saggio è stato possibile non solo quantificare la presenza di Double Strand Breaks (DSBs) spontanei ma anche di valutare le capacità riparative dei sistemi di riparazione specifici per questo tipo di lesioni a seguito del trattamento delle cellule con mitomicina C. A causa di una riduzione del numero di linfociti osservati e della presenza di cellule apoptotiche è stato necessario eseguire un’analisi volta a stimare la presenza di apoptosi nelle cellule T della popolazione esaminata. Quest’ultima valutazione è stata determinata mediante l’analisi morfologica dei nuclei e confermata poi da un TUNEL assay

Oxidative and DNA damage in obese patients undergoing bariatric surgery: A one-year follow-up study

The pathogenesis of obesity and related comorbidities has long been associated with oxidative stress. The excess of adipose tissue contributes to the production of free radicals that sustain both a local and a systemic chronic inflammatory state, whereas its reduction can bring to an improvement in inflammation and oxidative stress. In our work, using the fluorescent lipid probe BODIPY® 581/591 C11 and the γH2AX foci assay, a well-known marker of DNA double strand breaks (DSB), we evaluated the extent of cell membrane oxidation and DNA damage in peripheral blood lymphocytes of normal weight (NW) controls and obese patients sampled before and after bariatric surgery. Compared to NW controls, we observed a marked increase in both the frequencies of oxidized cells or nuclei exhibiting phosphorylation of histone H2AX in preoperatory obese patients. After bariatric surgery, obese patients, resampled over one-year follow-up, improved oxidative damage and reduced the presence of DSB. In conclusion, the present study highlights the importance for obese patients undergoing bariatric surgery to also monitor these molecular markers during their postoperative follow-up

Role of oxidative stress, genome damage and DNA methylation as determinants of pathological conditions in the newborn: an overview from conception to early neonatal stage

Increasing evidence suggests that early-life events can predispose the newborn to a variety of health issues in later life. In adverse pre- and perinatal conditions, oxidative stress appears to play an important role in the development of future pathological outcomes. From a molecular point of view, oxidative stress can result in genome damage and changes in DNA methylation that can in turn prime pathogenic mechanisms. Interestingly, both alterations have been related to a reciprocal regulation of oxidative stress. The aim of this review is to give a brief overview of the complex relationship linking oxidative stress to DNA damage and methylation and to go through the different sources of exposure that a neonate can encounter in utero or shortly after birth. In this context, the setup of methodologies to monitor the extent of oxidative stress, genomic damage and instability or the presence of altered methylation patterns contributes to the understanding on how the complex events occurring in early life can lead to either a healthy status or a pathological condition

UCTD and SLE patients show increased levels of oxidative and DNA damage together with an altered kinetics of DSB repair

: Immunological tolerance is a critical feature of the immune system; its loss might lead to an abnormal response of lymphocytes causing autoimmune diseases. One of the most important groups belonging to autoimmune disorders is the connective tissue diseases (CTD). CTD are classified among systemic rheumatic diseases and include pathologies such as systemic lupus erythematosus (SLE), and undifferentiated CTD (UCTD). In this study, we evaluated oxidative and genome damage in peripheral blood lymphocytes from patients with SLE and UCTD, further classified on the basis of disease activity and the presence/absence of a serological profile. Oxidative damage was evaluated in cell membrane using the fluorescent fatty acid analogue BODIPY581/591 C11. The percentage of oxidised lymphocytes in both SLE and UCTD patients was higher than in the control group, and the oxidative stress correlated positively with both disease activity and autoantibody profile. The γH2AX focus assay was used to quantify the presence of spontaneous double strand breaks (DSBs), and to assess the abilities of DSBs repair system after T cells were treated with mitomycin C (MMC). Subjects with these autoimmune disorders showed a higher number of γH2AX foci than healthy controls, but no correlation with diseases activity and presence of serological profile was observed. In addition, patients displayed an altered response to MMC-induced DSBs, which led their peripheral cells to greatly increase apoptosis. Taken together our results confirmed an interplay among oxidative stress, DNA damage and impaired DNA repair, which are directly correlated to the aggressiveness and clinical progression of the diseases. We propose the evaluation of these molecular markers to better characterise SLE and UCTD, aiming to improve the treatment plan and the quality of the patients' life

Innovations technologiques et mutations industrielles en Amérique latine

Pour l'Amérique latine, les années quatre-vingts ont été définies par la CEPAL comme la "décennie perdue", dominées par la crise financière, économique, sociale, liée notamment à l'endettement, et marquées globalement par une chute de la production et du revenu per-capita réel au-dessous du niveau atteint en 1980. Cette décennie est celle de la rupture forcée avec le modèle de développement "Cépalien", celle des politiques d'ajustement structurel et d'ouverture au marché mondial, celle de la reformulation des interventions de l'Etat et de son désengagement de la production directe. Cette révolution, qui est aussi celle des modèles de référence et des mentalités, est étroitement liée à la révolution générale industrielle et technologique mondiale et à la compétition accrue qu'elle instaure entre les économies nationales et les pôles les plus avancées (États-Unis, Japon, Europe). Le problème de la désindustrialisation et de la reconversion industrielle a d'ailleurs été en Amérique latine au cœur des débats sur les sorties de crise, et les politiques publiques de l'innovation et la capacité des États latino-américains à constituer les bases technologiques d'un développement endogène ont été sérieusement questionnées. Les innovations technologiques largement diffusées et implantées aujourd'hui dans les pays industriels sont relativement récentes en Amérique latine, où cette implantation se fait de manière hétérogène à l'intérieur des pays et des systèmes productifs ; elles se concentrent particulièrement dans certaines régions, dans certaines branches d'activités, dans certains types d'entreprises et d'administrations. Pourtant ce processus est doté d'une grande puissance et ses effets dépassent largement le simple cadre de l'économie globale de ces pays. La dynamique du système innovation-reconversion industrielle-ouverture aboutit également à une nouvelle géographie latino-américaine : à l'échelle du continent, elle accroît la distance entre pays forçant leur marche vers l'intégration au "premier Monde", comme le Mexique et pays enlisés dans la crise comme le Pérou ; à l'intérieur de chaque pays, elle change le poids et la qualité relative des régions, ouvrant une fracture entre zones d'industrie d'exportation et régions refuges et faisant se côtoyer territoires technopolitains et zones de pauvreté et d'exclusion