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Keywords:

  • human;
  • malaria;
  • proteomics;
  • red blood cell;
  • transfusion

Abstract

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

Background and objectives:  A most memorable scene in “Bram Stoker’s Dracula” of Francis Ford Coppola sees Count Vlad II of Wallachia proclaim: “The blood is the life It is impossible to evaluate how much the Irish novelist, writer of the 1897 book the film was based upon, was influenced by the developments in blood transfusion that characterized the end of the 19th and the beginning of the 20th century, but the word “transfusion” figures prominently in his manuscript. Past centuries had been characterized by successful blood transfusions between animals, but success in human transfusions had been limited prior to Landsteiner’s discovery of the red blood cell (RBC) membrane ABO antigens (1901) that permitted the establishment of safe blood transfusions. The application of refrigeration and anticoagulants to blood storage in the 1910s then paved the way to blood banking. Since those early days, developments in the RBC field have been tightly associated with technologies that changed science, allowing researchers to home into the detail (moving from blood to RBC and then to RBC membrane proteins) and had a huge impact on the quality of life. Today, proteomics technologies can be used to tackle important but neglected aspects of transfusion medicine, such as determining changes at the peptide and protein level during storage of blood products.

Results:  Studies have demonstrated that stored leucocyte-undepleted whole RBC populations release over 100 proteins compared to the few released by leucocyte-depleted blood units. The leucocyte-poor RBC predominantly released carbonic anhydrase and thioredoxin peroxidase B. The presence of oxygen, in this context, gives rise to extensive RBC surface modifications, which can be prevented by adding protease inhibitors. Proteins released during storage of leucocyte-depleted RBCs were found in form of microvesicles and nanovesicles enriched not only in integral membrane proteins, but specifically in oligomerized band 3, suggesting a preferential release of damaged cell components from otherwise functional RBCs. Flow cytometry was used in combination with proteomics to study storage of younger versus older RBCs. In leucocyte-depleted RBC stored for 42 days, phosphatidylserine exposure at the RBC membrane external surface did not increase and none of the surface markers studied decreased significantly, while the copy numbers of CD44, CD58, CD147 and glycophorin decreased and annexin release increased in RBC stored with leucocytes. A recent review summarizes the contribution of proteomics to transfusion medicine and puts forward a possible approach in form of a workflow for monitoring the quality of blood-based therapeutics by proteomics.

Conclusions:  Monitoring may be essential as more detailed analyses using state of the art mass spectrometry tools are likely to provide an even better insight into storage and environment-induced changes in the RBC that may be critical to optimize the quality of transfused RBC. Increasing our knowledge of the RBC protein make-up (low abundant proteins in particular); of their changes in health and disease and in the interplay with other blood cells/endothelial cells will also be beneficial in assessing changes in their quality, while the study of intra-species differences will be instrumental in the light of the passage from animal experimentation to clinical trials.

A most memorable scene in ‘Bram Stoker’s Dracula’ of Francis Ford Coppola sees Count Vlad II of Wallachia proclaim: ‘The blood is the life!’ It is impossible to evaluate how much the Irish novelist, writer of the 1897 book the film was based upon, was influenced by the developments in blood transfusion that characterized the end of the 19th and the beginning of the 20th century, but the word ‘transfusion’ figures prominently in his manuscript.

Since the early days, developments in the red blood cell (RBC) field have been tightly associated with technologies that changed science, allowing researchers to increasingly home into the detail, and had a huge impact on the quality of life. Experiments with blood transfusions had been carried out for hundreds of years prior to the discovery of the blood components, but it was the development of the microscope during the 17th century that made it possible for Dutch biologists Jan Swammerdam and Anton van Leeuwenhoek to first describe the RBC [1].

While successful blood transfusions between animals had already been established, success in human transfusions had been limited and the RBC became the focus of much scientific interest. Breakthroughs in immunological theory [e.g. Ehrlich’s antibody formation theory (1900)] and the description of serum components [e.g. the complement by Jules Bordet (1896)] influenced Landsteiner’s RBC studies leading to the discovery of the ABO RBC membrane antigens (1901) that permitted the establishment of safe blood transfusions. The application of refrigeration and anticoagulants to blood storage in the 1910s then paved the way to blood banking, while further steps towards increased blood transfusion safety were made with the discovery of the Rhesus blood group system by Landsteiner and Wiener in 1940.

During the 20th century in-depth biochemical, immunological and molecular characterization of single cellular proteins significantly increased our understanding of RBC structure/function leading to the identification of the 30 major blood groups currently recognized by the International Society of Blood Transfusion (ISBT). Towards the end of the century, new technologies emerged that allowed determination of entire m-RNA (micro-array, transcriptomics) and protein (mass spectrometry, proteomics) make-up of cells. Unlike proteomics, transcriptomics is not applicable when cells lack nuclei and transcription/translation machinery (e.g. mature RBC), and it only yields an incomplete cellular picture where m-RNA species are not translated to proteins. In these circumstances, proteomics is the method of choice for global protein determinations and offers the opportunity to tackle important but neglected aspects in transfusion medicine [2,3], such as determining changes at the peptide and protein level during storage of blood products [4].

General proteome overview of the healthy human RBC

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

The possibility to analyse modifications of the RBC protein and lipid make-up during disease or blood product storage is strongly dependent on the availability of in-depth information on the healthy mature RBC, as changes will ultimately be assessed by comparison.

A number of research groups have contributed proteome studies in the attempt to unravel the secrets of the healthy human RBC. In a pioneering study of the human RBC membrane using both 2D and 1D in-gel digestion prior to MS analysis, Low et al. [5] applied MALDI-TOF technology to identify 121 proteins. Using ESI-LC, Goodman et al. (2004) identified around 100 membrane and 100 soluble human RBC components using well-characterized membrane fractions such as inside-out vesicles and low salt extracts [6]. As the first RBC proteome studies were published, papers started to appear assessing the possible impact of this emerging technology on the haematology field [7–10].

A year later [11], a study aimed at developing new immobilized trypsin monolayers for digestion, and 2D nano HPLC separation of peptides to profile RBC proteins identified a total of 272 RBC soluble and membrane proteins. However, in this study, the RBC was a test-cell for this innovative methodology, and most assignments were low confidence. Thereafter, Thadikkaran et al. [12] provided a general overview on the status of blood proteomics discussing challenges and potentials. In 2006, we combined biochemical RBC sub-fractionation (Fig. 1) with recent MS-instrumentation advances, state of the art protein identification technology, statistically significant numbers of MS-runs and undertook in-depth post-proteomic validation and analysis of the emerging protein lists to identify 340 membrane and 252 soluble human RBC proteins [13].

image

Figure 1.  Differential extraction of RBC membrane proteins: selected examples. GPI, GPI-anchored proteins; LMA, loosely membrane-associated proteins; MB, membrane bound; IMP, integral membrane protein; CYTO, cytoskeletal; GLYCO, glycolytic proteins. The figure shows the range of peptides obtained using different extraction procedures and different MS technology/methods (each column represents at least three runs).

Download figure to PowerPoint

A few months after each other, in 2008, two groups presented different techniques aimed at depleting the RBC of abundant proteins to promote the discovery of low abundant RBC proteins [14,15]. While the identification of more low abundant proteins is likely with these methods, thus increasing the overall number of RBC proteins we know about, the attribution to the RBC proposed by the authors is problematic as purification from other blood components was not extensive and no attempt was made to eliminate reticulocytes, which are metabolically active and known to contain a much vaster array of proteins than mature RBCs [16].

RBC proteomics data have recently been summarized and organized into a RBC protein interactome [17] sketch, which was expanded and updated in a recent paper by D’Alessandro et al. [18].

Methods in RBC proteomics

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

The correct attribution of proteins uncovered by proteomics to a specific cell type is highly dependent on the purity of the starting material. Therefore, it is preferable to move away from the definition of proteomics as a mass spectrometry-based tool for protein expression studies [19] and to adopt a multi-step pipeline definition able to promote the awareness that every step is critical for final success (Fig. 2).

image

Figure 2.  Methods in mature RBC purification and proteomics analysis.

Download figure to PowerPoint

A classical proteomics experiment always starts with the isolation and purification of the material to be analysed. This step is key to the interpretation and reliability of results, because proteins of minor contaminating cell populations may lead to misattribution (e.g. attribution of granulocyte proteins to RBC) as mass spectrometry (MS) has become increasingly sensitive. The extent of purification needed is dependent on the aim of the analysis and the complexity of the sample at hand.

Furthermore, as false positives can also arise from database misidentification, it is important to combine high resolution and accuracy data with proper statistical techniques (e.g. decoy databases) to effectively address this issue.

For RBCs isolated for proteomic analysis, low-level contaminants are most likely to derive from other blood cells and plasma. To date, isolation/purification has involved some or all of the following: repeated washes with isotonic medium (removal of plasma and platelets), elimination of the buffy coat (upper layer) at each washing step, the use of filters (leucocyte removal), density gradients e.g. percol, renografin-percol (granulocyte, reticulocyte removal) and customized nets (granulocyte removal) [13].

Once the starting material is obtained, a number of different procedures have been proposed for its preparation/fractionation. Typically, to generate peptides suitable for MS, a purified sample is either enzymatically cleaved directly in solution or in-gel fractionated prior to enzymatic cleavage. However, recently, a filter-aided sample preparation method was published, which combines the advantages of in-gel and in-solution digestion [20]. In general, fractionation step(s) help reduce sample complexity and can help in subsequent protein allocation as they provide further information (e.g. MW in the case of SDS/PAGE or location when using membrane specific regimes) regarding the proteins from which peptides were derived.

The MS ionization method most often guides the choice between 1D- and 2D-SDS/PAGE for sample fractionation. 1D has traditionally been associated with electrospray ionization (ESI) and 2D with matrix-assisted laser desorption ionization (MALDI) as this requires a more extensive sample deconvolution because of the low specificity of peptide mass fingerprinting.

To address one of the major challenges in RBC proteomics, the huge dynamic range (e.g. Band 3 is 2000 times more abundant than the complement receptor 1), further steps can be taken – prior to MS analysis – to deplete abundant proteins, through chromatography [14,21], peptide libraries [15,22,23] or differential extraction [13,24,25] (e.g. for membranes using various solvents, detergents, ion-chelators and ionic solutions). While depletion procedures are uniquely aimed at improving the range of detection and generally target a specific abundant protein at a time, different extraction methodologies allow the detection of proteins with different biochemical characteristics. A limitation of depletion procedures is often in their relative specificity, which leads to the removal of low abundant, depleted protein-associated cell constituents. In this context, it is important to underline that none of these fractionation methodologies can substitute thorough cell purification. Furthermore, each method has advantages and disadvantages, and the choice of procedures should be guided by the aims of the proteomics study.

A number of different MS approaches can be used in the analysis: MALDI has generally been coupled to time of flight (TOF)-analyzers and ESI with ion-trap, quadrupole, Fourier transform ion cyclotrone (FT-MS) and Orbitrap analyzers. More recently, different peptide ionization methods have been coupled with different detectors. New MALDI instruments coupled with TOF/TOF analyzers or quadrupole ion traps have made protein identification of complex samples significantly easier and may in some cases supplant binomial 2D-MALDI-MS, but automation of MALDI-coupled liquid chromatography remains a challenge (2D-gel electrophoresis has limitations in reproducibility, dynamic range and depth of analysis).

In ESI-LC, peptides are analysed via a high-pressure liquid chromatography (HPLC)-coupled mass spectrometer, where the HPLC column provides peptide separation prior to injection into the MS.

Each peptide analysed by the MS has a typical mass to charge ratio (m/z), which is registered by a detector. The output of the MS is m/z ratio (or peaks) spectra for each peptide. These spectra are used to query a sample-related database (e.g. the human protein database) generated by software that performs an in-silico digest of all database proteins and generates the related peptide spectra. These spectra are compared with the experimental spectra by searching for matches, generating a score representing the quality of the match. The cut-off point for scores can be set to ensure that the peptides/proteins are likely to be real. A manual validation step with appropriate restrictive parameters enhances the accuracy of the final protein lists.

Comparative proteomics in transfusion medicine

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

The interaction between RBC membrane lipids, membrane transporters (maintenance of pH and cation concentration differentials), some membrane-bound enzymes (glycolytic enzymes) and the underlying cytoskeletal network is critical to the maintenance of the characteristic biconcave shape of the RBC, allowing for its fluidity and deformability [26]. The application of comparative proteomics to assess the quality of stored blood products has highlighted modifications in these critical proteins, which may indicate a transition towards less-functional RBCs during storage.

Studies have demonstrated that stored leucocyte-undepleted whole RBC populations release over 100 proteins compared to the few released by leucocyte-depleted blood units [27]. The leucocyte-poor RBC predominantly released carbonic anhydrase and thioredoxin peroxidase B [28] (Table 1). Annis et al. [27] found a number of serum-derived proteins to accumulate during RBC storage, such as Transthyretin, Preserum amyloid P and Igk. An explanation is proposed by Queloz et al. [28], who found that these proteins are absorbed on the RBC surface and later released during storage. D’Amici et al. found that the presence of oxygen in leucocyte non-depleted bags gives rise to extensive RBC surface modifications, which can be prevented by adding protease inhibitors [29] (Table 2). Proteins released during storage of leucocyte-depleted RBCs were found in form of nano- and microvesicles [30] enriched not only in integral membrane proteins, but specifically in oligomerized band 3, suggesting a preferential release of damaged cell components from otherwise functional RBCs. Immunoglobulins (IgG) and complement proteins deposed on the RBC during storage accumulated in nanovesicles, while haemoglobin accumulated in the RBC membrane fractions. The existence and association (independently confirmed by proteomics [13]) of high molecular covalent C3b2-IgG complexes to the human RBC membrane has been shown to be a characteristic of RBC ageing [31].

Table 1.   Comparison of changes in proteins from membranes of RBC stored under blood bank conditions with and without leucocytes (according to ref. 27, 28) and relative to stored RBC age (according to ref. 33)
Released from RBCs stored with leucocytes (day 28)Released from RBCs stored without leucocytes (day 28)
Accumulating with storage
 P02766 TransthyretinQ06830 Thioredoxin peroxidase B
 P02743 Preserum amyloid PP00915 Carbonic anhydrase I
 P01607 Igk 
 P02775 Col CTAP-III 
Non-Accumulating with storage
 P02679 Fibrinogen γ-chain 
 P02656 Apolipoprotein CIII-1 
Common high-abundance proteins
 Haemoglobin-relatedVitamins, calcium-binding proteins
 AlbuminHypotheticals
 Complement-relatedApolipoproteins
Released from RBCs stored with leucocytesReleased from RBCs stored without leucocytes
From young RBCsFrom young RBCsFrom young RBCsFrom old RBCs
  1. Symbol Legend: [UPWARDS ARROW] increased in supernatant & decrease on RBC [RIGHTWARDS ARROW] constant.

[UPWARDS ARROW] CD 44 (from day 28)[UPWARDS ARROW] CD 44 (from day 28) [UPWARDS ARROW] CD 44 (from day 28)
[UPWARDS ARROW] CD 147 (from day 28)[UPWARDS ARROW] CD 147 (from day 28) [UPWARDS ARROW] CD 147 (from day 28)
[RIGHTWARDS ARROW] CD 47 (from day 28)[UPWARDS ARROW] CD 47 (from day 28) [UPWARDS ARROW] GPA (from day 28)
[UPWARDS ARROW] CD 58 (from day 28)[UPWARDS ARROW] CD 58 (from day 28)  
[UPWARDS ARROW] GPA (from day 1)[UPWARDS ARROW] GPA (from day 1)  
[UPWARDS ARROW] Annexin V (from day 42)[UPWARDS ARROW] Annexin V (from day 42)  
Table 2.   Changes in proteins from membranes of RBC stored under blood bank conditions without leucocyte depletion (according to ref. 29)
Storage conditionsControlNo O2 − PINo O2 + PIO2 − PIO2 + PI
  1. Mv, mean value; PI, Protease Inhibitors; O2, oxygen; CT, cytoplasmic tail.

Day 0 mv1266////
Day 7 mv/13681294183431610
Day 7: Proteins in the new spots//Protein 42//
Protein 41
Band 3
55 kDa
β-Spectrin
α-spectrin
Flotillin 1
ADD2
Aldolase A
Arginase
GAPDH
β-Hb
Day 14 mv/1480136227522328
Day 14: Additional fragments////β-Spectrin
α-spectrin
Ankyrin
Band 49
GAPDH
Protein 41
β-actin
E-Tmod
Band 3-CT
β-Spectrin
TSP

Microvesicles shed by RBCs during storage analysed by Lion et al. [32] appeared to display proteomic profile markedly different from their parent cells, especially in terms of processed proteins.

As the life span of the RBC is around 120 days, it is important to consider that stored blood is a heterogeneous mixture comprising young, medium and old RBCs. These different RBCs may express a different behaviour vis-à-vis the presence of other blood components during storage. In an elegant study, flow cytometry (FACS) was used in combination with proteomics to study storage of younger versus older RBCs. In leucocyte-depleted RBC stored for 42 days, phosphatidylserine exposure at the RBC membrane external surface did not increase and none of the surface markers studied decreased significantly, while the copy numbers of CD44, CD58, CD147 and glycophorin A (GPA) decreased and annexin V release increased in RBCs stored with leucocytes [33] (Table 1). However, the FACS-coupled proteomics picture of the incidence of modifications in young and adult RBC stored 28 days long shows that old RBCs from leucocyte-depleted bags already start loosing CD44, CD147 and GPA, while young RBCs do not. An interesting difference in leucocyte non-depleted preparation is the continuous loss of CD47 by old RBC, while CD47 in young RBCs remains constant. This is important as literature suggests that a depletion of CD47 may be involved in the clearance of RBCs from circulation by macrophages. The losses of cytoskeletal (spectrin/ankyrin) and CD47, between day 21 and 42, have been confirmed by Bosman et al. [30], who described also the disappearance of membrane-bound metabolic enzymes, signal transduction proteins and small G proteins.

Further, it should be considered that the detection of annexin V in RBC supernatants might be a good indicator of storage lesions. A recent review [34] summarizes the contribution of proteomics to transfusion medicine and puts forward a possible approach in form of a workflow for monitoring the quality of blood-based therapeutics by proteomics. This monitoring may be essential as more detailed analyses using state of the art mass spectrometry tools are likely to provide an even better insight into storage and environment-induced changes in the RBC that may be critical to optimize the quality of transfused RBC.

Proteomics, the RBC and transfusion medicine: limitations and future perspectives

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

RBC proteomic analyses are complicated by factors that include large ranges in expression levels; post-translational modifications that affect peptide molecular weight; occurrence of closely related isoforms, absence of appropriate database descriptors for a specific protein and the ubiquitous presence of haemoglobin. In terms of large ranges in expression, it is noteworthy that protein band 3 occurs at one million copies per cell, comprising 30% of the membrane proteome, and spectrin tetramer occurs at 100 000 copies per cell, comprising 75% of the cytoskeleton. Our recent experience suggests that use of the latest ESI-MS technology coupled to membrane extraction methodologies and repeated runs allows the confident detection of proteins at levels down to 500 copies per cell (e.g. CR1). The high concentration of haemoglobin (97% of soluble RBC protein dry mass and 35% of the total mass) and its tendency to associate strongly with the membrane hamper detection of low abundant membrane and soluble proteins. Reduce membrane association is obtained by performing RBC lyses at low temperature (≤ 4°C). Depletion methods for abundant RBC proteins have recently been developed to overcome these limitations. It remains unclear how selective these methods are, and whether a number of other proteins, which strongly associate with haemoglobin, are lost by their application.

Distinguishing protein isoforms and highly homologous family members is complex. They may be characterized by long identical and short highly specific stretches (e.g. different glucose transporters); differ only by single point mutations (MN antigens displayed by GPA and GPB) or be short/long versions of the same protein (Glycophorins C and D). While it is possible to apply targeted MS-software-based approaches (e.g. inclusion and exclusion lists) when stretches highly specific to an isoform or family member are present, traditional MS analysis has limited potential when proteins differ only by single point mutations and offers no possibility to distinguish short protein variants. Glycomics studies [35] that differentiate between proteins based on their characteristic sugars (e.g. GPD carries only O-linked sugar chains, while GPC also carries one N-linked sugar chains in position 8) may become extremely useful adjuncts to proteomics studies as well as being informative in their own right. Thus, glycomics will contribute to study of the complex RBC carbohydrate heterogeneity that gives rise to a much blood group antigen diversity and immunology.

Interactomics and bioinformatics-based domain analysis will, on the other hand, help move traditional, identification-based proteomics into the domain of providing functional insight, for example by providing maps of the interactions between adjacent membrane proteins that create specific micro-domains and epitopes with important functional implications (e.g. interaction between domains on band 3 and GPA resulting in the Wright (Wrb) blood type). The combination of interactomics and bioinformatics with open-access protein databases will help unravel the exciting field of dynamic relationships between the RBC and its environment.

In contrast to proteomics, lipidomics is still is in its infancy and faces a number of technological challenges. In future, this approach may help unravel poorly abundant RBC membrane lipids with important physiological functions, disclose the secrets of raft formation, answer questions on preferential protein–lipid interactions and promote a more in-depth understanding of phopsholipid exchange and repair.

In transfusion medicine, where the final aim is providing patients with qualitatively ameliorated blood-therapeutics, proteomics offers the possibility to detect storage lesions [including post-translational modification (PTMs [36])], but also to monitor the product’s quality during all steps of the blood banking production chain [37]. In particular, in the study of RBC, PTMs progress will need to be made before the presence/absence of certain PTMs can be applied as a tool in RBC quality assessment, but proteomics has the undoubted potential to become an important part of the quality-control process to verify the identity, purity, safety and potency of blood components [37]. In this context, the combination of proteomics and classic immunohaematology may help to better evaluate potential alterations and changes in products stored for transfusion and guide towards the selection of manufacturing processes least likely to generate unwanted post-translational protein modifications [38].

Proteomics could also be used to address other areas such as pathogen inactivation, in which this technology could be used to screen compounds that inactivate viruses and bacteria while monitoring for adverse effects on plasma proteins or the induction of cell alterations [39].

According to Reddy et al. [39], high-throughput proteomics techniques may in future become instrumental to the detection of transfusion-transmitted agents and in the development of microbial antigen arrays for early sero-diagnosis of both common and rare infectious diseases. The availability would help in the effort to further shorten ‘window’ periods. Hess and Grazzini (2010) [37], see a most important perspective in the use of proteomics as a research tool to understand the storage lesions, guide the development of better red cell storage conditions and inform blood banking regulation. A word of caution is in order concerning the application of comparative proteomics: it is essential that sample analysis conditions (same isolation, purification, fractionation, MS machinery and methods) be identical to allow for results comparability. Thus, extensive standardization between laboratories and platforms may be required, before proteomics is established as a worldwide blood products-monitoring tool.

Of potential relevance to the transfusion medicine field, is the emerging information suggesting that the RBC may carry markers for systemic diseases such as schizophrenia [40]. While proteomic studies of RBCs at the epidemiological level, using large-scale population-based cohorts to monitor RBC membrane changes and uncover risk factors/systemic disease markers for cancer and metabolic syndromes, have recently been proposed [41], it remains unclear whether the presence of these non-RBC proteins in blood products for transfusion may have consequences.

Thus, while identification-based proteomics has limitations, and while it is not clear whether the levels of sensitivity already achieved can usefully be improved upon, related technologies such as interactomics, lipidomics, glycomics and population proteomics are rapidly coming on line. Coupled with bioinformatics and systems biology approaches, these have the potential to shed light on the systemic influence of the RBC and influences upon the RBC as it travels through the body and interacts with an ever changing environment.

In this context, proteomics offers a unique possibility to understand the complexity of blood and blood products and improve their usage. Increasing our knowledge of the RBC protein make-up (low abundant proteins in particular); of their changes in health [26] and disease [42] and in the interplay with other blood cells/endothelial cells [43] will be beneficial in assessing changes in their quality, while the study of intraspecies differences will be instrumental in the light of the passage from animal experimentation to clinical trials [13,44,45].

Acknowledgements

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References

The authors thank Dr Hans Lutz from the ETH Zürich for helpful discussion. This work was supported by the ZonNW-NGI HORIZON doorbraakproject (dossiernummer 93519014), the NWO-CLS malaria (dossiernummer 635100026) and the European Network of Excellence EviMalaR (grant number 242095).

References

  1. Top of page
  2. Abstract
  3. General proteome overview of the healthy human RBC
  4. Methods in RBC proteomics
  5. Comparative proteomics in transfusion medicine
  6. Proteomics, the RBC and transfusion medicine: limitations and future perspectives
  7. Acknowledgements
  8. Disclosures
  9. References