in-vitro-assay-to-evaluate-impact-immunoregulatory-pathways-on-hiv

<em>In Vitro</em> Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function

T cell exhaustion is a major factor in failed pathogen clearance during chronic viral infections. Immunoregulatory pathways, such as PD-1 and IL-10, are ...

The Ragon Institute of MGH, MIT and Harvard

T cell dysfunction in the presence of ongoing antigen exposure is a cardinal feature of chronic viral infections with persistent high viremia, including HIV-1. Although interleukin-10 (IL-10) has been implicated as an important mediator of this T cell dysfunction, the regulation of IL-10 production in chronic HIV-1 infection remains poorly understood. We demonstrated that IL-10 is elevated in the plasma of individuals with chronic HIV-1 infection and that blockade of IL-10 signaling results in a restoration of HIV-1-specific CD4 T cell proliferation, gamma interferon (IFN-Î³) secretion, and, to a lesser extent, IL-2 production. Whereas IL-10 blockade leads to restoration of IFN-Î³ secretion by HIV-1-specific CD4 T cells in all categories of subjects investigated, significant enhancement of IL-2 production and improved proliferation of CD4 T helper cells are restricted to viremic individuals. In peripheral blood mononuclear cells (PBMCs), this IL-10 is produced primarily by CD14(+) monocytes, but its production is tightly controlled by regulatory T cells (Tregs), which produce little IL-10 directly. When Tregs are depleted from PBMCs of viremic individuals, the effect of the IL-10 signaling blockade is abolished and IL-10 production by monocytes decreases, while the production of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-Î±), increases. The regulation of IL-10 by Tregs appears to be mediated primarily by contact or paracrine-dependent mechanisms which involve IL-27. This work describes a novel mechanism by which regulatory T cells control IL-10 production and contribute to dysfunctional HIV-1-specific CD4 T cell help in chronic HIV-1 infection and provides a unique mechanistic insight into the role of regulatory T cells in immune exhaustion.

CD4+ CD25+ regulatory T cells impair HIV-1-specific CD4 T cell responses by upregulating interleukin-10 production in monocytes.

Dysfonction des cellules t en pr&eacute;sence de l&#39;exposition de l&#39;antig&egrave;ne en cours est une fonctionnalit&eacute; Cardinale des infections virales chroniques avec persistance une vir&eacute;mie &eacute;lev&eacute;e, y compris le VIH-1. Bien que l&#39;interleukine-10 (IL-10) a &eacute;t&eacute; mis en cause comme un m&eacute;diateur important de ce dysfonctionnement de la cellule T, la r&eacute;gulation de la production d&#39;IL-10 dans chronique HIV-1 infection reste mal comprise. Nous avons d&eacute;montr&eacute; que l&#39;IL-10 est &eacute;lev&eacute;e dans le plasma des individus pr&eacute;sentant une infection chronique du VIH-1 et que le blocage de l&#39;IL-10 r&eacute;sultats signalisation dans une restauration de la prolif&eacute;ration des cellules T CD4 sp&eacute;cifiques au VIH-1, la s&eacute;cr&eacute;tion d&#39;interf&eacute;ron (IFN-&gamma;) gamma et, dans une moindre mesure, la production de IL-2. Alors que le blocus de l&#39;IL-10 conduit &agrave; restauration de s&eacute;cr&eacute;tion d&#39;IFN-&gamma; par des cellules T CD4 sp&eacute;cifiques au VIH-1 dans toutes les cat&eacute;gories de sujets &eacute;tudi&eacute;s, une am&eacute;lioration significative de la production IL-2 et am&eacute;lioration de prolif&eacute;ration des cellules T CD4 auxiliaires sont limit&eacute;s aux personnes vir&eacute;miques. Dans les cellules mononucl&eacute;aires du sang p&eacute;riph&eacute;rique (PBMC), cet IL-10 est produite principalement par les monocytes CD14(+), mais sa production est &eacute;troitement contr&ocirc;l&eacute;e par les lymphocytes T r&eacute;gulateurs (Tregs), qui produisent peu d&#39;IL-10 directement. Lorsque Tregs sont &eacute;puis&eacute;es de PBMC de personnes vir&eacute;miques, l&#39;effet de l&#39;IL-10 signalisation blocus est abolie et la production d&#39;IL-10 par des diminutions de monocytes, tandis que la production de cytokines pro-inflammatoires, telles que le facteur de n&eacute;crose tumorale alpha (TNF-&alpha;), augmente. Le r&egrave;glement d&#39;IL-10 par Tregs semble &ecirc;tre m&eacute;di&eacute;es principalement par contact ou paracrine d&eacute;pendant des m&eacute;canismes qui impliquent des IL-27. Ce travail d&eacute;crit un nouveau m&eacute;canisme par lequel des cellules T r&eacute;gulatrices contr&ocirc;lent la production d&#39;IL-10 et contribuent &agrave; dysfonctionnel aide de cellules T CD4 sp&eacute;cifiques au VIH-1 dans l&#39;infection chronique par le VIH-1 et jette un regard m&eacute;caniste unique sur le r&ocirc;le des lymphocytes T r&eacute;gulateurs d&#39;&eacute;puisement immunitaire.

Lymphocytes T r&eacute;gulateurs CD4 + CD25 + alt&eacute;rer les lymphocytes T CD4 sp&eacute;cifiques au VIH-1 par la production d&#39;interleukin-10 cytoprotectrices dans les monocytes.

Disfunzione delle cellule t in presenza di esposizione dell&#39;antigene in corso &egrave; una caratteristica cardinale di infezioni virali croniche con viremia elevata persistente, tra cui l&#39;HIV-1. Sebbene interleukin-10 (IL-10) &egrave; stato implicato come un mediatore importante di questa disfunzione delle cellule T, la regolazione della produzione di IL-10 in resti di infezione HIV-1 cronici mal capito. Abbiamo dimostrato che IL-10 &egrave; elevata nel plasma di individui con infezione cronica da HIV-1 e quel blocco di IL-10 segnalazione risultati in un restauro di proliferazione delle cellule T CD4 HIV-1-specifiche, la secrezione di gamma interferone (IFN-&gamma;) e, in misura minore, produzione IL-2. Considerando che IL-10 blocco porta a restauro di secrezione di IFN-&gamma; da parte delle cellule T CD4 specifici dell&#39;HIV-1 in tutte le categorie di soggetti indagati, significativo aumento della produzione di IL-2 e maggiore proliferazione delle cellule helper CD4 T sono limitati ai soggetti viremici. In cellule mononucleate di sangue periferico (PBMCs), questo IL-10 &egrave; prodotto principalmente da CD14(+) monociti, ma la produzione &egrave; strettamente controllata da cellule di T regolatorie (Tregs), che producono direttamente IL piccolo-10. Quando Tregs sono esaurite da PBMCs di soggetti viremici, aumenta l&#39;effetto di IL-10 segnalazione blocco &egrave; abolito e di produzione di IL-10 da diminuzioni di monociti, mentre la produzione di citochine proinfiammatorie, come fattore di necrosi tumorale alfa (TNF-&alpha;). Il regolamento di IL-10 da Tregs sembra essere mediate principalmente da contatto o paracrina-dipendente meccanismi che coinvolgono IL 27. Questo lavoro descrive un meccanismo romanzo che cellule T regolatorie controllano la produzione di IL-10 e contribuiscono a disfunzionali aiuto di cellule T CD4 specifici dell&#39;HIV-1 nell&#39;infezione cronica da HIV-1 e fornisce una visione meccanicistica unica il ruolo delle cellule T regolatorie in esaurimento immunitario.

CD4 + CD25 + cellule T regolatorie compromettere le risposte delle cellule T CD4 HIV-1-specifiche di produzione di interleuchina-10 upregulating nei monociti.

The development of immunomonitoring models to determine HIV-1 vaccine efficacy is a major challenge. Studies suggest that HIV-1â€“specific CD8 T cells play a critical role in subjects achieving spontaneous viral control (HIV-1 controllers) and that they will be important in immune interventions. However, no single CD8 T-cell function is uniquely associated with controller status and the heterogeneity of responses targeting different epitopes further complicates the discovery of determinants of protective immunity. In the present study, we describe immunomonitoring models integrating multiple functions of epitope-specific CD8 T cells that distinguish controllers from subjects with treated or untreated progressive infection. Models integrating higher numbers of variables and trained with the least absolute shrinkage and selection operator (LASSO) variant of logistic regression and 10-fold cross-validation produce â€œdiagnostic testsâ€ that display an excellent capacity to delineate subject categories. The test accuracy reaches 75% area under the receiving operating characteristic curve in cohorts matched for prevalence of protective alleles. Linear mixed-effects model analyses show that the proliferative capacity, cytokine production, and kinetics of cytokine secretion are associated with HIV-1 control. Although proliferative capacity is the strongest single discriminant, integrated modeling of different dimensions of data leverages individual associations. This strategy may have important applications in predictive model development and immune monitoring of HIV-1 vaccine trials.

Meghan G. Hart

The Ragon Institute of MGH, MIT and Harvard

In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function