PhD Program

Project Title: Oncogenic factors in CEBPA deficient leukemias: functional characterization and mechanisms of action
Supervisor: Meritxell Alberich Jorda

Project Description:
Acute myeloid leukemia (AML) is a malignant neoplasia of the hematopoietic system resulting in the accumulation of leukemic blasts in the bone marrow and peripheral blood. Various disease-related single gene mutations have been described that directly influence leukemia progression and prognosis. Interestingly, the transcription factor C/EBPa is inactivated in approximately 50% of AML, contributing to the block of myeloid differentiation characteristic of this disease. In the present project we will identify oncogenic factors altered in C/EBPa deficient leukemias. We will focus on coding genes as well as long non-coding RNAs, and explore their contribution to leukemogenesis. The project will involve cell culture techniques, murine in vivo models, and genome-wide screening approaches.

Candidate Profile:
The laboratory of hemato-oncology is searching for a highly motivated, enthusiastic and hard-working Ph.D student. The candidate should hold a master degree in genetics, molecular biology, cell biology, or in a related field. The candidate should be willing to work with murine models. Excellent English is required. The candidate should be a team-player and willing to work with other lab members and international collaborators. We offer a friendly and supporting environment in a state-of-the-art institution.

Suggested reading:

• Liss A, Ooi CH, et al. The gene signature in CCAAT-enhancer-binding protein α dysfunctional acute myeloid leukemia predicts responsiveness to histone deacetylase inhibitors. Haematologica. 2014 Apr;99(4):697-705.
• Zjablovskaja P, Kardosova M, et al. EVI2B is a C/EBPa target gene required for granulocytic differentiation and functionality of hematopoietic progenitors. Cell Death Differ. 2017 Apr;24(4):705-716.
• Wurm AA, Zjablovskaja P, et al. Disruption of the C/EBPα-miR-182 balance impairs granulocytic differentiation. Nat Commun. 2017 Jun 29;8(1):46.
• Kardosova M, Zjablovskaja P, et al. C/EBPg is dispensable for steady-state and emergency granulopoiesis. Haematologica. 2018 Aug;103(8):e331-e335.

Project Title: Exploring mechanisms of DNA replication restart upon collisions between transcription and replication complexes
Supervisors: Pavel Janščák / Jana Dobrovolná

Project Description:
Transcription-replication collisions (TRCs) represent a significant source of genomic instability in cells experiencing DNA replication stress. Although there is a great deal of knowledge about the strategies that cells evolved to avoid TRCs, understanding of how a replication fork restarts DNA synthesis upon a TRC remains elusive. Our recent studies have shown that replication restart upon R-loop-mediated TRCs relies on MUS81 endonuclease, RAD52 single-strand annealing protein and DNA ligase 4 (LIG4). In this project, we aim to use a proteomic approach to identify and functionally characterize new factors involved in this process.

Candidate Profile:
Applicants should be graduates in Molecular Biology/Cellular Biology/Biochemistry with a strong interest in basic research and experimental work. Good English and independent thinking is required. The projects offer training in a broad range of molecular, cell biological and biochemical techniques. The student will also undergo short-term trainings at the Institute of Molecular Cancer Research of the University of Zurich where he/she will be exposed to front-line research in the field of DNA repair and cancer.

Suggested reading:

• Di Marco S, Hasanova Z, Kanagaraj R, Chappidi N, Altmannova V, Menon S, Sedlackova H, Langhoff J, Surendranath K, Hühn D, Bhowmick R, Marini V, Ferrari S, Hickson ID, Krejci L, Janscak P. (2017) RECQ5 Helicase Cooperates with MUS81 Endonuclease in Processing Stalled Replication Forks at Common Fragile Sites during Mitosis. Mol. Cell 66(5), 658-671.
• Urban V, Dobrovolna J, Hühn D, Fryzelkova J, Bartek J, Janscak P. (2016) RECQ5 helicase promotes resolution of conflicts between replication and transcription in human cells. J. Cell Biol. 214(4), 401-15.

Project Title: Mechanisms of cell reprogramming
Supervisor: Petr Bartůněk

Project Description:
The project will focus on mechanisms of epigenetic control of hematopoietic cell reprogramming using unique model of zebrafish erythroid progenitor cell line that can be reprogrammed into myeloid lineage using cytokine switch only. The candidate will employ already established methods like ATAC-seq, ChIP-seq, RNAseq and further develop single-cell-based technologies.

Candidate Profile:
MSc or equivalent with strong background in biochemistry and molecular/cell biology.

Suggested reading:

• Graf T (2011) Historical origins of transdifferentiation and reprogramming. Cell Stem Cell. 9(6):504-16.
• Svoboda O, Stachura DL, Machonova O, Pajer P, Brynda J, Zon LI, Traver D, Bartunek P.* Dissection of vertebrate hematopoiesis using zebrafish thrombopoietin. Blood. 2014; 124(2):220-8.
• Svoboda O, Stachura DL, Machonova O, Zon LI, Traver D, Bartunek P.* Ex vivo tools for the clonal analysis of zebrafish hematopoiesis, Nat Protocols. 2016; 11(5):1007-20.

Project Title: The role of mutations in adaptor protein PSTPIP2 in autoinflammatory disease
Supervisor: Tomáš Brdička

Project Description:
The project will focus on explaining the mechanisms contributing to the development of autoinflammatory disease in animals carrying mutations in adaptor protein PSTPIP2. The candidate will explore the molecular mechanisms of how PSTPIP2 suppresses inflammatory signalling in neutrophils and other leukocytes of myeloid lineage and how the disease develops when this protein is mutated or absent. The project will include analysis of leukocyte development, migration, immune response and signalling pathways using genetically modified mouse models and cell lines. The disease closely resembles several human autoinflammatory bone disorders and the relevance of the results obtained within this project for human autoinflammatory disease will also be studied. In addition, the candidate will be involved in projects exploring function of other adaptor proteins involved in the regulation of leukocyte signalling and inflammation.

Candidate Profile:
The candidate must hold a Master degree (or be close to its completion) in immunology, molecular/cell biology, biochemistry or in related field of life sciences. The applicant must have a strong interest in immunology and related biomedical sciences. Ability to communicate in English is required.

Suggested reading:

• Drobek A, Kralova J, Skopcova T, et al. PSTPIP2, a Protein Associated with Autoinflammatory Disease, Interacts with Inhibitory Enzymes SHIP1 and Csk. J Immunol. 2015;195(7):3416-3426.
• Ferguson PJ, Laxer RM. New discoveries in CRMO: IL-1beta, the neutrophil, and the microbiome implicated in disease pathogenesis in Pstpip2-deficient mice. Semin Immunopathol. 2015;37(4):407-412.

Project Title: Adaptor protein OPAL1 in hematopoiesis, bone marrow transplantation and leukemia  
Supervisor: Tomas Brdicka

Project Description:
Until now OPAL1 has only been known at mRNA level as childhood leukemia marker, expression of which correlated with ETV6-RUNX1 translocation and favorable treatment outcome. Our unpublished work shows the involvement of OPAL1 protein in chemokine receptor signalling and in other pathways relevant for leukemia prognosis and development. Using OPAL1 deficient mice and cell lines, the candidate will study the mechanisms of how OPAL1 regulates hematopoiesis, various leukocyte functions and leukemic cell biology. Biochemical analysis of OPAL1 interactome and signalling pathways regulated by OPAL1 will also be included in the project. In addition, the candidate will be involved in exploring other adaptor proteins involved in the regulation of leukocyte signalling and development.

Candidate Profile:
The candidate must hold a Master degree (or be close to its completion) in immunology, molecular/cell biology, biochemistry or in related field of life sciences. The applicant must have a strong interest in immunology, haematology and related biomedical sciences. Ability to communicate in English is required.

Suggested reading:

• Mosquera-Caro M, Helman P, Veroff R, et al. Identification, validation and cloning of a novel gene (OPAL1) and associated genes highly predictive of outcome in pediatric acute lymphoblastic leukemia using gene expression profiling [abstract]. Blood. 2003;102(4a.
• Holleman A, den Boer ML, Cheok MH, et al. Expression of the outcome predictor in acute leukemia 1 (OPAL1) gene is not an independent prognostic factor in patients treated according to COALL or St Jude protocols. Blood. 2006;108(6):1984-1990.
• Pei J, Grishin NV. Unexpected diversity in Shisa-like proteins suggests the importance of their roles as transmembrane adaptors. Cell Signal. 2012;24(3):758-769.

Project Title: The role of extracellular matrix stiffness and composition in development of liver
Supervisors: Martin Gregor

Project Description:
Liver fibrosis is excessive scarring process resulting from chronic insults of heterogenous etiology. The major hallmark of liver fibrosis is deposition of fibrous extracellular matrix (ECM) synthetized mainly by hepatic stellate cells (HSCs). The major goal of this project is analysis of interplay between HSCs and altering ECM niche, using newly developed mouse model harboring HSCs with compromized ECM-receptor signaling. This phenomena will be then studied in vitro, using human HSC line and mouse primary HSCs to better understand the processes regulating deposition and composition of ECM in liver fibrosis.

The successful candidates will learn and utilize advanced cell-biology, molecular-biology, physiology, imaging techniques and atomic force microscopy, while developing and analyzing various mouse models.

Candidate Profile:
We are seeking outstanding self-motivated candidates with master’s degree in molecular biology, physiology, biochemistry or related fields. We are offering research at a state-of-the-art equipped institute with experienced colleagues, international working environment and international collaborations.

Suggested reading:

• Gregor M. et al. Mechanosensing through focal adhesion-anchored intermediate filaments. FASEB J., 28:715-29, 2014.
• Burgstaller G. et al. Keeping the vimentin network under control: cell–matrix adhesion-associated plectin 1f affects cell shape and polarity of fibroblasts. Mol. Biol. Cell, 21:3362–3375, 2010.
• Jirouskova M. et al. Plectin Controls Biliary Tree Architecture and Stability in Cholestasis. J Hepatol., 68:1006-1017, 2018.
• Duscher D. Mechanotransduction and fibrosis. J Biomech. 47:1997–2005, 2014.

Project Title: Virus-host cell interactions
Supervisors: Jiří Hejnar

Project Description:
The project will focus on cellular factors involved in the retrovirus (mostly ALV, MLV, HIV, HERV) infection and replication. Particular attention will be paid to factors responsible for retrovirus entry. In chicken-ALV system, genome editing will be performed with the aim to confer resistance to virus infection. Our projects are extended from in silico to in vivo levels.

Candidate Profile:
Curiosity and commitment for basic science are expected. We also appreciate proper background in experimental virology, cell cultures and molecular biology. Previous experience with CRISPR/Cas9 editing would be helpful. The candidate should be prepared for long hours and bad jokes in a big team.

Project Title: Functions of lamin A – phosphoinositides complexes in the cell nucleus
Supervisor: Pavel Hozák

Project Description:
Lamins are intermediate filament proteins involved in a variety of nuclear functions, such as regulation of gene expression, DNA replication, DNA repair, chromatin organization, and cellular signaling. Mutations in lamins cause severe diseases – laminopathies. Lamins in the cell nucleus exist in two distinct pools – in nuclear lamina and in the nuclear interior. While much less is known about the nucleoplasmic lamins, their functional specificity and importance in gene expression has been increasingly recognized. Our preliminary data demonstrate that lamin A forms a range of complexes with phosphatidylinositol 4,5-bisphosphate exhibiting different mechanism of binding and different composition. This project focuses on detailed characterization of these complexes by biochemical, structural and advanced microscopy methods using various experimental models. The project will implement molecular biology and biochemistry methods as well as the state-of-the-art imaging techniques including fluorescence, confocal and super-resolution (SIM, STED, STORM) microscopy. The project is supported by recently awarded funding from the Grant Agency of the Czech Republic.

Candidate Profile:
M.Sc. (Mgr.) degree or equivalent in molecular/cellular biology or biochemistry, good English, independent thinking, strong interest in basic research and experimental work, dedication to learn and develop new techniques.

Suggested reading:

• de Leeuw, R., Gruenbaum, Y. & Medalia, O. Nuclear Lamins: Thin Filaments with Major Functions. Trends Cell Biol 28, 34-45 (2018) and references therein.
• Gesson, K. et al. A-type lamins bind both hetero- and euchromatin, the latter being regulated by lamina-associated polypeptide 2 alpha. Genome Res 26, 462-473 (2016).
• Sobol, M. et al. Nuclear phosphatidylinositol 4,5-bisphosphate islets contribute to efficient RNA polymerase II-dependent transcription. J Cell Sci (2018).
• Sztacho, M. et al. Nuclear phosphoinositides and phase separation: Important players in nuclear compartmentalization. Advances in biological regulation (2018).

Project Title: The role of phosphoinositides in spatiotemporal regulation of nuclear processes.
Supervisor: Pavel Hozák

Project Description:
Phosphoinositides (PIPs) are recognized as regulators of many nuclear processes including chromatin remodeling, splicing, transcription, and DNA repair. These processes are spatially organized in different nuclear compartments. Various nuclear compartments are formed by entropy-driven mechanism – phase separation. The surface of such membrane-less structures spatiotemporally coordinates complex nuclear processes. The integration of PIPs into the surface of nuclear structures might therefore provide an additional step in their functional diversification by controlling the localization of different components, in a similar way as PIPs do in membranous cytoplasmic environment. This project focuses on deciphering the molecular mechanisms of various PIPs in establishing a dynamic nuclear architecture. In this project PhD candidate will characterize the PIPs-containing nuclear structures by combination of lipidomics, proteomics (quantitative MS), molecular biology (e.g. CRISPR/Cas9), biochemical and advanced microscopy (e.g. confocal, SIM, STED, FRAP) methods. The project is supported by funding from the Grant Agency of the Czech Republic.

Candidate Profile:
M.Sc. (Mgr.) degree or equivalent in molecular biology, biochemistry of biophysics. The candidate should be fluent in English, independent, with passion to science, willing to learn and develop new techniques.

Suggested reading:

• Sobol, M., A. Krausova, S. Yildirim, I. Kalasova, V. Faberova, V. Vrkoslav, V. Philimonenko, P. Marasek, L. Pastorek, M. Capek, Z. Lubovska, L. Ulicna, T. Tsuji, M. Lisa, J. Cvacka, T. Fujimoto, and P. Hozak. 2018. Nuclear phosphatidylinositol 4,5-bisphosphate islets contribute to efficient RNA polymerase II-dependent transcription. J Cell Sci. 131.
• Sztacho, M., M. Sobol, C. Balaban, S.E. Escudeiro Lopes, and P. Hozak. 2018. Nuclear phosphoinositides and phase separation: Important players in nuclear compartmentalization. Adv Biol Regul. and references therein.

Project Title: Exploring the role of vinculin/DEB-1 in eukaryotic meiosis
Supervisor: Pavel Hozák / Petr Flachs

Project Description:
Our department focuses on the vinculin/DEB-1 protein, and we originally confirmed it in the nucleus of meiotic cells in Mus musculus and C. elegans. Our goal is to study his role in the gametogenesis of this two eukaryotic model organisms. We study vinculin in mouse spermatogenesis and oogenesis using model strains of vinculin conditional knock-out that we developed in our laboratory. Specifically, we proved that vinculin is important for homologous chromosome pairing and formation of the synaptonemal complex, possibly through the vicnulin involvement in the ubiquitine-proteasome system. In C. elegans we showed the interaction of the DEB-1 (ortholog of mammalian vinculin) with the SUN/KASH module at the nuclear periphery. DEB-1 depletion caused a defect in the stabilization of the chromosomal pairing centers and subsequent aneuploidy. The PhD project will implement molecular biology and biochemistry methods as well as the state-of-the-art imaging techniques including fluorescence, confocal and super-resolution (SIM, STED) microscopy (SIM figure in the heading, such a detailed picture of synaptonemal complex would not be possible few years ago). The project is supported by funding from the Grant Agency of the Czech Republic.

Candidate Profile:
Candidates should possess M.Sc. (Mgr.) degree or equivalent in molecular/cellular biology or biochemistry, good English, independent thinking, strong interest in basic research and experimental work, dedication to learn and develop new techniques.

Suggested reading:
All articles are open access (free)!

• Bisig et al, 2012; Synaptonemal Complex Components Persist at Centromeres and Are Required for Homologous Centromere Pairing in Mouse Spermatocytes; PLOS genetics
• Shakes et al, 2009; Spermatogenesis-Specific Features of the Meiotic Program in Caenorhabditis elegans; PLOS genetics
• Shibuya et al, 2014; The Dissection of Meiotic Chromosome Movement in Mice Using an In Vivo Electroporation Technique; PLOS genetics

Project Title: Impact of PPM1D/Wip1 phosphatase on chromatin organization in human cells
Supervisor: Libor Macurek

Project Description:
Genome instability caused by defects in DNA repair can contribute to various pathologies including cancer. Genome integrity is protected by coordinated action of molecular pathways that control the cell cycle and DNA repair. In addition to the signaling at the DNA break, DNA damage also affects organization of the chromatin at pan-nuclear level. This project aims to study changes in the chromatin organization caused by genotoxic stress.

Protein phosphatase PPM1D/Wip1 is localized at chromatin and inactivates cellular response to DNA damage. Here we will address the impact PPM1D/Wip1 phosphatase on chromatin organization in human cells. In particular we will compare distribution of the heterochromatin in control cells, cells where PPM1D/Wip1 was inactivated by CRISPR/Cas9 technology and in cells treated with a small molecule inhibitor of PPM1D/Wip1. Chromatin organization will be studied in normal conditions and after induction of DNA damage using various molecular and cell biology techniques. We expect that this project will contribute to better understanding of cellular responses to DNA damage.

Candidate Profile:
We seek a motivated PhD student to join our young international team located in Prague, Czech Republic. We are especially interested in candidates with strong background in molecular/cell biology or biochemistry and with enthusiasm for basic science and experimental work.

Suggested reading:

• Jaiswal et al., ATM/Wip1 activities at chromatin control Plk1 re-activation to determine G2 checkpoint duration. EMBO J. 2017; 36:2161-2176.
• Kleiblova et al., Gain-of-function mutations of PPM1D/Wip1 impair the p53-dependent G1 checkpoint. J Cell Biol. 2013; 201:511-21.
• Macůrek et al., Wip1 phosphatase is associated with chromatin and dephosphorylates gammaH2AX to promote checkpoint inhibition. Oncogene. 2010; 29:2281-91.

Project Title: Unraveling oncogenic signaling that imparts tumors with tolerance to nutrient starvation  
Supervisor: Mohamed Elgendy

Project Description:
Tumors require dramatically high levels of energy to fuel their rapid growth. Solid tumors often grow in metabolically-challenging microenvironments far from blood and nutrient supply. How tumor cells adapt their metabolism to meet these metabolic challenges, have always fascinated scientists. Almost a century ago, Otto Warburg suggested that tumor cells specifically uptake high levels of glucose, which they metabolize through the process of glycolysis to generate the energy and biomass they need. Indeed, tracing radio-labeled glucose administrated to cancer patients is routinely used in the clinic to visualize tumors and detect metastasis. Surprisingly however, specific inhibitors developed to inhibit glycolysis failed to eliminate tumors when tested clinically. So it seems that while some tumors may upregulate glycolysis, they are able to tolerate the inhibition of glycolysis through shuffling to other metabolic pathways. This project aims to dissect oncogenic signaling that mediates metabolic adaptations of tumors. The work aims to unravel how activation of certain oncogenes influences the ability of tumors to tolerate specific metabolic challenges.

Candidate Profile:

• Motivated
• Motivated again!
• High learning capabilities
• Prior experience in cellular and molecular biology is advantageous
• Master’s degree in medicine, biology or relevant fields

Suggested reading:

• Fundamentals of cancer metabolism.
• Beclin 1 restrains tumorigenesis through Mcl-1 destabilization in an autophagy-independent reciprocal manner.

Project Title: The role of new candidate genes in glucose homeostasis and insulin sensitivity
Supervisors: Jan Rozman

Project Description:
Among several other genes, C4orf22 and CNBD1 were recently found to show a link to dysfunctional glucose homeostasis and impaired insulin sensitivity both in knockout mutant mice as well as in genome wide association studies in humans (Rozman et al. 2018). The exact physiological roles of these genes and their involvement in the development of metabolic disorders on the genetic and molecular level are unknown so far. The project will focus on the in-depth characterization of one or two candidate genes both on the physiological and the molecular level. The candidate will make use of different mouse models with the aim to characterize new targets for the diagnosis and possibly treatment of diabetes.

Candidate Profile:
We are seeking a PhD student to join our new research team at the Czech Center for Phenogenomics in Prague, Czech Republic. Candidates with a strong background both in physiology, molecular biology and animal models in the field of energy metabolism and diabetes are strongly encouraged to apply for the new position.

Suggested reading:
Rozman, J., Rathkolb, B., Oestereicher, M.A., Schütt, C., Ravindranath, A.C., Leuchtenberger, S., Sharma, S., Kistler, M., Willershäuser, M., Brommage, R., et al. (2018). Identification of genetic elements in metabolism by high-throughput mouse phenotyping. Nature communications 9, 288.

Project Title: Assembly of the spliceosome
Supervisors: David Staněk

Project Description:
RNA splicing, a key step in eukaryotic gene expression, is catalyzed by one of the most complex and dynamic particles in the cells – the spliceosome. The spliceosome consists of several building blocks, each of them contains non-coding RNAs and dozens of proteins. These ribonucleoprotein building blocks do not assemble spontaneously but require a number of auxiliary proteins that promote their correct formation and control the quality of the assembly process. The main objective of this PhD project is to investigate, utilizing a wide-range of life-cell imaging microscopy techniques in combination with molecular biology and biochemistry approaches, how are spliceosomal components correctly assembled in the dynamic and complex cell environment.

Candidate Profile:
We seek an enthusiastic colleague with strong interest in RNA biology. Previous experience with molecular biology, biochemistry and/or light microscopy is welcomed.

Requirements:

• MSc, MRes, Diploma or an equivalent degree in Biology, Biomedicine, Chemistry or related sciences, to be obtained latest by the start of the fall term in September 2019
• Practical experience in the lab working on scientific projects
• Excellent English language skills and the desire to work in a dynamic international team

Suggested reading:

• Roithová A., Klimešová K., Pánek J., Cindy L.W., Lührmann R., Staněk D. & Girard C. (2018) The Sm-core mediates the retention of partially-assembled spliceosomal snRNPs in Cajal bodies until their full maturation. Nuc. Acids Res. 46(7):3774–3790.
• Krausová M. & Staněk D. (2017) snRNP proteins in health and disease. Sem. Cell Dev. Biol. S1084-9521(17)30150-7 (review).
• Staněk D. & Fox A. (2017) Nuclear bodies: news insights into structure and function. Curr. Op. Cell Biol 46:94-101 (review).
• Staněk D. (2017) Cajal body and snRNPs – friends with benefits. RNA Biology, 14(6):671-679 (review).
• Novotný I., Malinová A., Stejskalová E., Matějů D., Klimešová K., Roithová A., Švéda M., Knejzlík Z. & Staněk D. (2015) SART3-dependent accumulation of incomplete spliceosomal snRNPs in Cajal bodies. Cell Rep. 10:429–440.

Project Title: Phenotypic and clonal diversity of T cells
Supervisors: Ondřej Štěpánek

Project Description:
T cells orchestrate adaptive immune responses to infection and cancer, but also can induce autoimmunity or allergy. It is clear that diversity of individual types and subtypes of T cells is very large and that particular subsets have unique functions, but we still do not understand the functional differences between individual T-cell subsets completely. Such understanding is a key requirement for a design of sophisticated therapies to cancer, infection, and autoimmune disorders.
The PhD student will use novel tools developed in our lab to study the clonal and phenotypic heterogeneity in T cells. The main objective is to reveal how phenotypic and clonal heterogeneity of CD8+ T cells determine adaptive immune responses. Two specific aims are: (i) Functional differences between naive, memory, and virtual memory T cells and (ii) Role of self-reactivity in antigenic responses of naive T cells. We offer enthusiastic and supportive international environment with strong grant support (including high-profile ERC funding).

Candidate Profile:
We are looking for a highly motivated candidate with a strong commitment to science. The candidate should posses M.Sc. or equivalent in immunology, cell biology, molecular biology or related fields and wet lab experience (e.g., MSc. project), good laboratory practice, and ethics. Previous experience with experimental immunology and/or animal models is an advantage, but not required.

We strongly encourage candidates to contact the PI directly (ondrej.stepanek@img.cas.cz) prior to the PhD Interviews.

Suggested reading:

• Drobek A, Moudra A, Mueller D, Huranova M, Horkova V, Pribikova M, Ivanek R, Oberle S, Zehn D, McCoy KD, Draber P, Stepanek O: Strong homeostatic TCR signals induce formation of self-tolerant virtual memory CD8 T cells. EMBO J 2018 37(14).
• Michaela Pribikova, Alena Moudra, Ondrej Stepanek: Opinion: Virtual memory CD8 T cells and lymphopenia-induced memory CD8 T cells represent a single subset: Homeostatic memory T cells. Immunology Letters 2018 203: 57-61.