The immunology field has invested great efforts and ingenuity to characterize the various immune cell types and elucidate their functions. However, accumulating evidence indicates that current ...technologies and classification schemes are limited in their ability to account for the functional heterogeneity of immune processes. Single-cell genomics hold the potential to revolutionize the way we characterize complex immune cell assemblies and study their spatial organization, dynamics, clonal distribution, pathways, function, and crosstalks. In this Perspective, we consider recent and forthcoming technological and analytical advances in single-cell genomics and the potential impact of those advances on the future of immunology research and immunotherapy.
Recent and forthcoming technological and analytical advances in single-cell genomics have the potential to shape the future of immunology research and immunotherapy.
Despite rapid developments in single cell sequencing, sample-specific batch effects, detection of cell multiplets, and experimental costs remain outstanding challenges. Here, we introduce Cell ...Hashing, where oligo-tagged antibodies against ubiquitously expressed surface proteins uniquely label cells from distinct samples, which can be subsequently pooled. By sequencing these tags alongside the cellular transcriptome, we can assign each cell to its original sample, robustly identify cross-sample multiplets, and "super-load" commercial droplet-based systems for significant cost reduction. We validate our approach using a complementary genetic approach and demonstrate how hashing can generalize the benefits of single cell multiplexing to diverse samples and experimental designs.
Immuno-positron emission tomography (immunoPET) is a paradigm-shifting molecular imaging modality combining the superior targeting specificity of monoclonal antibody (mAb) and the inherent ...sensitivity of PET technique. A variety of radionuclides and mAbs have been exploited to develop immunoPET probes, which has been driven by the development and optimization of radiochemistry and conjugation strategies. In addition, tumor-targeting vectors with a short circulation time (e.g., Nanobody) or with an enhanced binding affinity (e.g., bispecific antibody) are being used to design novel immunoPET probes. Accordingly, several immunoPET probes, such as 89Zr-Df-pertuzumab and 89Zr-atezolizumab, have been successfully translated for clinical use. By noninvasively and dynamically revealing the expression of heterogeneous tumor antigens, immunoPET imaging is gradually changing the theranostic landscape of several types of malignancies. ImmunoPET is the method of choice for imaging specific tumor markers, immune cells, immune checkpoints, and inflammatory processes. Furthermore, the integration of immunoPET imaging in antibody drug development is of substantial significance because it provides pivotal information regarding antibody targeting abilities and distribution profiles. Herein, we present the latest immunoPET imaging strategies and their preclinical and clinical applications. We also emphasize current conjugation strategies that can be leveraged to develop next-generation immunoPET probes. Lastly, we discuss practical considerations to tune the development and translation of immunoPET imaging strategies.
Recent advances in flow cytometry allow scientists to measure an increasing number of parameters per cell, generating huge and high-dimensional datasets. To analyse, visualize and interpret these ...data, newly available computational techniques should be adopted, evaluated and improved upon by the immunological community. Computational flow cytometry is emerging as an important new field at the intersection of immunology and computational biology; it allows new biological knowledge to be extracted from high-throughput single-cell data. This Review provides non-experts with a broad and practical overview of the many recent developments in computational flow cytometry.
The classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in ...humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127(-) and CD127(+) early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127(-) and CD127(+) ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127(-) ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127(+) ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis.
Macrophage aggregates (MAs) are focal accumulations of pigmented macrophages in the spleen and other tissues of fish. A central role of MAs is the clearance and destruction of degenerating cells and ...recycling of some cellular components. Macrophage aggregates also respond to chemical contaminants and infectious agents and may play a role in the adaptive immune response. Tissue damage or physiological stress can result in increased MA accumulation. As a result, MAs may be sensitive biomarkers of environmental stress in fish. Abundance of MAs in tissues has been reported in a variety of ways-most commonly as density, mean size, and relative area-but the utility of these estimates has not been compared. In this study, four different types of splenic MA abundance estimates (abundance score, density, relative area, and total volume) were compared in two fish populations (Striped Bass Morone saxatilis and White Perch M. americana) with a wide range in ages. Stereological estimates of total volume indicated an increase in MA abundance with spleen volume, which generally corresponded to fish age, and with splenic infections (mycobacteria or trematode parasites). Abundance scores were generally limited in the ability to detect changes in MA abundance by these factors, whereas density estimates were greatly influenced by changes in spleen volume. In some instances, densities declined while the total volume of MAs and spleen volume increased. Experimentally induced acute stress resulted in a decrease in spleen volume and an increase in MA density, although the total volume of MAs remained unchanged. Relative area estimates accounted for the size and number of MAs but not for changes in organ volume. Total volume is an absolute measure of MA abundance irrespective of changes in organ volume or patterns of accumulation and may provide an improved means of quantifying MAs in the spleens of fish.
Systems-biology approaches in immunology take various forms, but here we review strategies for measuring a broad swath of immunological functions as a means of discovering previously unknown ...relationships and phenomena and as a powerful way of understanding the immune system as a whole. This approach has rejuvenated the field of vaccine development and has fostered hope that new ways will be found to combat infectious diseases that have proven refractory to classical approaches. Systems immunology also presents an important new strategy for understanding human immunity directly, taking advantage of the many ways the immune system of humans can be manipulated.
The complex heterogeneity of cells, and their interconnectedness with each other, are major challenges to identifying clinically relevant measurements that reflect the state and capability of the ...immune system. Highly multiplexed, single-cell technologies may be critical for identifying correlates of disease or immunological interventions as well as for elucidating the underlying mechanisms of immunity. Here we review limitations of bulk measurements and explore advances in single-cell technologies that overcome these problems by expanding the depth and breadth of functional and phenotypic analysis in space and time. The geometric increases in complexity of data make formidable hurdles for exploring, analyzing and presenting results. We summarize recent approaches to making such computations tractable and discuss challenges for integrating heterogeneous data obtained using these single-cell technologies.
Objective
To evaluate the quality and accuracy of serological diagnosis of canine visceral leishmaniasis in the Americas.
Methods
A systematic review found original studies in the databases MEDLINE, ...EMBASE and LILACS up to November 2012 and in complementary sources up to February 2013. Studies were evaluated in accordance with QUADAS 2 and STARD parameters and recommended in accordance with GRADE parameters. Meta‐analysis was carried out with Meta‐DiSc software, using the random‐effect model.
Results
Two hundred and eighty‐four studies were identified, of which 25 met the inclusion criteria, comprising the final synthesis. All but one was conducted in Brazil, and only two were judged to be of good quality. 15 studies involving immuno‐enzymatic tests with crude antigens (cELISA), 11 studies on indirect immunofluorescence tests (IFAT) and three on the immunochromatographic dual‐path platform (DPP) test were meta‐analysed. The combined results for sensitivity and specificity were cELISA: 0.89 (CI 95% 0.87–0.91) and 0.87 (CI 95% 0.86–0.88); IFAT: 0.88 (CI 95% 0.85–0.91) and 0.63 (CI 95% 0.61–0.65); and DPP: 0.83 (CI 95% 0.78–0.88) and 0.73 (CI 95% 0.70–0.75).
Conclusion
Enzyme‐linked immunosorbent assay with crude antigens and DPP tests have moderate accuracy for the diagnosis of canine visceral leishmaniasis, and the quality of the design, implementation and analysis of validation studies on diagnostic tests for this disease urgently require improvement. The recommendation for use of the evaluated tests is based on evidence that is scarce and restricted to Brazil.
Objectif
Evaluer la qualité du diagnostic sérologique de la leishmaniose viscérale canine dans les Amériques.
Méthodes
Une revue systématique a retrouvé des études originales dans la base de données MEDLINE, EMBASE et LILACS jusqu’à novembre 2012 et des sources complémentaires jusqu’à février 2013. Les études ont été évaluées conformément aux paramètres QUADAS 2 et STARD et ont été recommandées selon les paramètres de GRADE. La méta‐analyse a été effectuée avec le logiciel MetaDiSc, en utilisant le modèle à effets aléatoires.
Résultats
284 études ont été identifiées, dont 25 répondaient aux critères d'inclusion constituant la synthèse finale. Toutes les études sauf une ont été réalisées au Brésil et seulement deux ont été jugées de bonne qualité. 15 études impliquant des tests immunoenzymatiques avec des antigènes bruts (cELISA), 11 études sur des tests d'immunofluorescence indirecte (IFAT) et 3 sur le test immunochromatographique de double plate‐forme (DPP) ont été incluses dans la méta‐analyse. Les résultats combinés pour la sensibilité et la spécificité étaient: cELISA: 0,89 (IC95%: 0,87 à 0,91) et 0,87 (IC95%: 0,86 à 0,88); IFAT: 0,88 (IC95%: 0,85 à 0,91) et 0,63 (IC95%: 0,61 à 0,65) et DPP: 0,83 (IC95%: 0,78 à 0,88) et 0,73 (IC95%: 0,70 à 0,75).
Conclusion
Les tests cELISA et DPP ont une précision modérée pour le diagnostic de la leishmaniose viscérale canine et la qualité du concept, l'implémentation et l'analyse des études de validation sur les tests de diagnostic pour cette maladie devraient urgemment être améliorées. La recommandation pour l'utilisation des tests évalués est basée sur des preuves rares et limitées au Brésil.
Objetivo
Evaluar la calidad del diagnóstico serológico de la leishmaniosis visceral canina en las Américas.
Métodos
Se encontraron estudios originales mediante una revisión sistemática en las bases de datos de MEDLINE, EMBASE y LILACS (hasta Noviembre 2012) y en fuentes complementarias (hasta Febrero del 2013.) Los estudios se evaluaron de acuerdo con los parámetros QUADAS 2 y STARD y fueron recomendaron siguiendo los parámetros GRADE. El meta‐análisis se realizó con el software de MetaDiSc, utilizando un modelo de efectos aleatorios.
Resultados
Se identificaron 284 estudios, de los cuales 25 cumplían criterios de inclusión, y formaron parte de la síntesis final. Todos, excepto uno, se habían llevado a cabo en Brasil y solo dos fueron considerados como de buena calidad. Se realizó el meta‐análisis con 15 estudios que incluían pruebas inmunoenzimáticas con antígenos crudos (cELISA), 11 estudios con pruebas de inmunofluorescencia indirecta (IFAT) y 3 mediante prueba inmunocromatográfica en plataforma con tecnología de vía doble (DPP). Los resultados combinados de sensibilidad y especificidad eran: cELISA: 0.89 (IC 95% 0.87 a 0.91) y 0.87 (IC 95% 0.86 a 0.88); IFAT: 0.88 (IC 95% 0.85 a 0.91) y 0.63 (IC 95% 0.61 a 0.65) y DPP: 0.83 (IC 95% 0.78 a 0.88) y 0.73 (IC 95% 0.70 a 0.75).
Conclusión
Las pruebas cELISA y DPP tienen una precisión moderada para el diagnóstico de la leishmaniosis visceral canina y la calidad del diseño, la implementación y el análisis de los estudios de validación sobre las pruebas diagnósticas para esta enfermedad requieren de una mejora urgente. La recomendación para el uso de las pruebas evaluadas está basada en una escasa evidencia y restringida al Brasil.
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