Project description:The purpose of this study was to investigate oral microbiome and host proteins in archaeological human dental tissues using a shotgun proteomics approach. The research focuses on dental calculus (mineralized plaque), dentine, a carious lesion, and an alveolar bone abscess from the medieval site of Dalheim, Germany (ca. AD 950-1200). For comparison, proteins were also analyzed from archaeological faunal dental tissues and human dental calculus samples from modern Swiss dental patient controls. Protein extraction and generation of tryptic peptides from tooth and dental calculus specimens was performed using a filter-aided sample preparation (FASP) protocol, modified for mineralized and degraded samples. Total protein extraction was performed on a total of fourteen samples: four ancient human calculus samples (indicated as: G12, B71, B61, and B78), four ancient human tooth root samples (indicated as: G12, B17, B61, and B78), one carious lesion (indicated as: B17), one alveolar bone abscess (indicated as: B17), two ancient fauna crown cementum/calculus samples (indicated as: F1 [sheep] and F5 [cattle]), and two modern dental calculus samples from clinical patients (indicated as: P1 and P2). All samples were extracted at the Centre for Evolutionary Medicine (ZEM) at the University of Zürich with the exception of dental calculus from G12, P1, and P2, which were extracted at the Center for GeoGenetics (CGG) at the University of Copenhagen. Two samples (G12 and B61 calculus) were extracted a second time in an independent laboratory at the University of York (YORK) for comparison. Sample extracts were then sequenced (LC-MS/MS) at the Functional Genomics Center Zürich (FGCZ) using an LTQ-Orbitrap Velos, at the Novo Nordisk Foundation Center for Protein Research (CPR) using a Q-Exactive Hybrid Quadrupole Orbitrap, and at the University of York’s Proteomics and Analytical Biochemistry Laboratories (PABL) using a MaXis UHR-Qq-TOF.
Project description:Archaeological materials are a finite resource, and efforts should be made to minimize destructive analyses. This can be achieved by using protocols combining extraction of several lines of evidence, which decreases the material needed for analyses while maximizing the information yield. Archaeological dental calculus is a source of several different types of biomolecules, as well as microfossils, and can tell us about the human host, microbiome, diet, and even occupational activities. Here, we present a unified protocol allowing for simultaneous extraction of DNA and proteins from archaeological dental calculus. We evaluate the protocol on dental calculus from a range of ages and estimated preservation states, and compare it against standard DNA-only and protein-only protocols. We find that most aspects of downstream analyses are unaffected by the unified protocol, although minor shifts in the recovered proteome can be detected. Protein recovery depends on both the amount of starting material and choice of extraction protocol, whereas DNA recovery is significantly lowered through the unified protocol. However, DNA recovery from dental calculus is generally very high, and we found no differences in DNA fragment characteristics or taxonomic profile. In conclusion, the unified protocol allows for simultaneous extraction of two complementary lines of evidence from archaeological dental calculus without compromising downstream analyses, thereby minimizing the need for destructive analysis of this finite resource.
Project description:The purpose of this study was to investigate oral microbiome and host proteins in archaeological human dental tissues using a shotgun proteomics approach. The research focuses on dental calculus (mineralized plaque), dentine, a carious lesion, and an alveolar bone abscess from the medieval site of Dalheim, Germany (ca. AD 950-1200). For comparison, proteins were also analyzed from archaeological faunal dental tissues and human dental calculus samples from modern Swiss dental patient controls. Protein extraction and generation of tryptic peptides from tooth and dental calculus specimens was performed using a filter-aided sample preparation (FASP) protocol, modified for mineralized and degraded samples. Total protein extraction was performed on a total of fourteen samples: four ancient human calculus samples (indicated as: G12, B71, B61, and B78), four ancient human tooth root samples (indicated as: G12, B17, B61, and B78), one carious lesion (indicated as: B17), one alveolar bone abscess (indicated as: B17), two ancient fauna crown cementum/calculus samples (indicated as: F1 [sheep] and F5 [cattle]), and two modern dental calculus samples from clinical patients (indicated as: P1 and P2). All samples were extracted at the Centre for Evolutionary Medicine (ZEM) at the University of Zürich with the exception of dental calculus from G12, P1, and P2, which were extracted at the Center for GeoGenetics (CGG) at the University of Copenhagen. Two samples (G12 and B61 calculus) were extracted a second time in an independent laboratory at the University of York (YORK) for comparison. Sample extracts were then sequenced (LC-MS/MS) at the Functional Genomics Center Zürich (FGCZ) using an LTQ-Orbitrap Velos, at the Novo Nordisk Foundation Center for Protein Research (CPR) using a Q-Exactive Hybrid Quadrupole Orbitrap, and at the University of York’s Proteomics and Analytical Biochemistry Laboratories (PABL) using a MaXis UHR-Qq-TOF.
Project description:Recent improvements in the analysis ancient biomolecules from human remains and associated dental calculus have provided new insights into the prehistoric diet and past genetic diversity of our species. Here we present a “multi-omics” study, integrating genomic and proteomic analyses of two post-Last Glacial Maximum (LGM) individuals from San Teodoro cave (Italy), to reconstruct their lifestyle and the post-LGM resettlement of Europe. Our analyses show genetic homogeneity in Sicily during the Palaeolithic, representing a hitherto unknown Italian genetic lineage within the previously identified “Villabruna cluster”. We argue that this lineage took refuge in Italy during the LGM, followed by a subsequent spread to central-western Europe. Analyses of dental calculus using genomics and proteomics showed a similar oral microbiome composition as Neandertals, but distinct from later foragers and farmers, revealing also a diet based on mammals, fish and plants. Our results demonstrate the power of using a multi-omics approach in the study of prehistoric human populations.
Project description:Mineralised dental plaque (calculus) has proven to be an excellent source of ancient biomolecules. In this study we present a Mycobacterium leprae genome (6.6-fold), the causative agent of leprosy, recovered via shotgun sequencing of 16th century human dental calculus from an individual from Trondheim, Norway. Moreover, ancient mycobacterial peptides were retrieved via mass spectrometry-based proteomics, further validating the presence of the pathogen. M. leprae can readily be detected in the oral cavity and associated mucosal membranes, which likely contributed to it being incorporated into this individual’s dental calculus. This individual showed some possible, but not definitive, evidence of skeletal lesions associated with early stage leprosy. This study is the first known example of successful multi-omics retrieval of M. leprae from archaeological dental calculus. Furthermore, we offer new insights into dental calculus as an alternative sample source to bones or teeth for detecting and molecularly characterizing M. leprae in individuals from the archaeological record.
Project description:The dental calculus proteome from human remains is a considered a valuable archaeological resource for studying the diet, oral microbiome, health/disease of individuals and occupation activities individuals within past societies/civilisations. The combination of advancements in LC/MS instrument sensitivity and sample prepartion methods enables the analysis of these well preserved proteomes otherwise invisible to other biomolecular approaches. Maximizing proteome recovery from this minute and finite resource is paramount to our understanding of these past societies and civilisations in terms of diet and disease. Here we compare the more traditional ultrafiltration-based and acetone precipitation approaches with the newer paramagnetic bead approach (SP3) in a step towards achieving this aim. We specifically evaluate different acids (EDTA and HCl) and proteome extraction methodologies (Ultrafiltration, Acetone Precipitation and SP3)to test the influence of demineralization acid and method of extraction on the recovered proteome complexity (including numbers of peptides recovered) and sequence coverageand observed for these ancient dental calculus specimens.
Project description:Archaeological dental calculus has emerged as a rich source of ancient biomolecules, including proteins. Previous analyses of proteins extracted from ancient dental calculus revealed the presence of the dietary milk protein β-lactoglobulin, providing direct evidence of dairy consumption in the archaeological record. However, the potential for calculus to preserve other food-related proteins has not yet been systematically explored. Here we analyse shotgun metaproteomic data from 100 archaeological dental calculus samples ranging from the Iron Age to the post-medieval period (8thC BC - 19thC AD) in Britain, as well as dental calculus from contemporary dental patients and recently deceased individuals, to characterise the range and extent of dietary proteins preserved in dental calculus. In addition to milk proteins, we detected proteomic evidence of foodstuffs such as cereals and plant products, as well as the digestive enzyme salivary amylase. We discuss the importance of optimized protein extraction methods, data analysis approaches, and authentication strategies in the identification of dietary proteins from archaeological dental calculus. Our ability to detect dietary proteins, although limited, demonstrates the potential of these methods to robustly identify foodstuffs in the archaeological record that are under-represented due to their poor preservation.