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Kremling V, Loll B, Pach S, Dahmani I, Weise C, Wolber G, Chiantia S, Wahl MC, Osterrieder N, Azab W. Crystal structures of glycoprotein D of equine alphaherpesviruses reveal potential binding sites to the entry receptor MHC-I. Front Microbiol 2023; 14:1197120. [PMID: 37250020 PMCID: PMC10213783 DOI: 10.3389/fmicb.2023.1197120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 04/18/2023] [Indexed: 05/31/2023] Open
Abstract
Cell entry of most alphaherpesviruses is mediated by the binding of glycoprotein D (gD) to different cell surface receptors. Equine herpesvirus type 1 (EHV-1) and EHV-4 gDs interact with equine major histocompatibility complex I (MHC-I) to initiate entry into equine cells. We have characterized the gD-MHC-I interaction by solving the crystal structures of EHV-1 and EHV-4 gDs (gD1, gD4), performing protein-protein docking simulations, surface plasmon resonance (SPR) analysis, and biological assays. The structures of gD1 and gD4 revealed the existence of a common V-set immunoglobulin-like (IgV-like) core comparable to those of other gD homologs. Molecular modeling yielded plausible binding hypotheses and identified key residues (F213 and D261) that are important for virus binding. Altering the key residues resulted in impaired virus growth in cells, which highlights the important role of these residues in the gD-MHC-I interaction. Taken together, our results add to our understanding of the initial herpesvirus-cell interactions and will contribute to the targeted design of antiviral drugs and vaccine development.
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Affiliation(s)
- Viviane Kremling
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Berlin, Germany
| | - Bernhard Loll
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Szymon Pach
- Institute of Pharmacy (Pharmaceutical Chemistry), Freie Universität Berlin, Berlin, Germany
| | - Ismail Dahmani
- Universität Potsdam, Institut für Biochemie und Biologie, Potsdam, Brandenburg, Germany
| | - Christoph Weise
- BioSupraMol Core Facility, Bio-Mass Spectrometry, Freie Universität Berlin, Berlin, Germany
| | - Gerhard Wolber
- Institute of Pharmacy (Pharmaceutical Chemistry), Freie Universität Berlin, Berlin, Germany
| | - Salvatore Chiantia
- Universität Potsdam, Institut für Biochemie und Biologie, Potsdam, Brandenburg, Germany
| | - Markus C. Wahl
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Berlin, Germany
| | - Nikolaus Osterrieder
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Berlin, Germany
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Walid Azab
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Berlin, Germany
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Jaworska J, Ropka-Molik K, Wocławek-Potocka I, Siemieniuch M. Inter- and intrabreed diversity of the major histocompatibility complex (MHC) in primitive and draft horse breeds. PLoS One 2020; 15:e0228658. [PMID: 32012208 PMCID: PMC6996847 DOI: 10.1371/journal.pone.0228658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/21/2020] [Indexed: 12/14/2022] Open
Abstract
Background Polymorphism of major histocompatibility complex (MHC) genes ensures effective immune responses against a wide array of pathogens. However, artificial selection, as performed in the case of domestic animals, may influence MHC diversity. Here, we investigate and compare the MHC diversity of three populations of horses, for which different breeding policies were applied, to evaluate the impact of artificial selection and the environment on MHC polymorphism. Methods Samples of DNA were taken from 100 Polish draft horses, 38 stabled Konik Polski horses and 32 semiferal Konik Polski horses. MHC alleles and haplotype diversity within and between these populations of horses was estimated from 11 MHC microsatellite loci. Results MHC diversity measured based on allelic richness, observed heterozygosity, expected heterozygosity and polymorphism content was similar across the MHC microsatellite loci in all three populations. The highest expected heterozygosity was detected in semiferal primitive horses (He = 0.74), while the lowest was calculated for draft horses (He = 0.65). In total, 203 haplotypes were determined (111 in Polish draft horses, 43 in semiferal Konik Polski horses and 49 in stabled Konik Polski horses), and four haplotypes were shared between the two populations of Koniks. None of these haplotypes were present in any of the previously investigated horse breeds. Intra-MHC recombination events were detected in all three populations. However, the population of semiferal Konik horses showed the highest recombination frequency among the three horse populations. In addition, three recombination events were detected. Conclusions These results showed that despite the different breeding policies, the MHC allele and haplotype diversity was similarly high in all three horse populations. Nevertheless, the proportion of new haplotypes in the offspring was the highest in semiferal Konik Polski horses, which indicates the influence of the environment on MHC diversity in horses. Thus, we speculate that the genetic makeup of the domestic horse MHC might be more strongly influenced by the environment than by artificial selection. Moreover, intra-MHC conversion, insertion, and deletion and intra-MHC recombination may be proposed as mechanisms underlying the generation of new MHC haplotypes in horses.
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Affiliation(s)
- Joanna Jaworska
- Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
- * E-mail:
| | - Katarzyna Ropka-Molik
- Department of Animal Molecular Biology, National Research Institute of Animal Production, Balice, Poland
| | - Izabela Wocławek-Potocka
- Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
| | - Marta Siemieniuch
- Research Station of the Institute of Reproduction and Food Research, Polish Academy of Sciences in Popielno, Ruciane-Nida, Poland
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Azab W, Osterrieder K. Initial Contact: The First Steps in Herpesvirus Entry. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2018; 223:1-27. [PMID: 28528437 DOI: 10.1007/978-3-319-53168-7_1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The entry process of herpesviruses into host cells is complex and highly variable. It involves a sequence of well-orchestrated events that begin with virus attachment to glycan-containing proteinaceous structures on the cell surface. This initial contact tethers virus particles to the cell surface and results in a cascade of molecular interactions, including the tight interaction of viral envelope glycoproteins to specific cell receptors. These interactions trigger intracellular signaling and finally virus penetration after fusion of the viral envelope with cellular membranes. Based on the engaged cellular receptors and co-receptors, and the subsequent signaling cascades, the entry pathway will be decided on the spot. A number of viral glycoproteins and many cellular receptors and molecules have been identified as players in one or several of these events during virus entry. This chapter will review viral glycoproteins, cellular receptors and signaling cascades associated with the very first interactions of herpesviruses with their target cells.
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Affiliation(s)
- Walid Azab
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany.
| | - Klaus Osterrieder
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Str. 7-13, 14163, Berlin, Germany
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Sadeghi R, Moradi-Shahrbabak M, Miraei Ashtiani SR, Miller DC, Antczak DF. MHC haplotype diversity in Persian Arabian horses determined using polymorphic microsatellites. Immunogenetics 2017; 70:305-315. [PMID: 29170799 DOI: 10.1007/s00251-017-1039-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 10/19/2017] [Indexed: 01/15/2023]
Abstract
Previous research on the equine major histocompatibility complex (MHC) demonstrated strong correlations between haplotypes defined by polymorphic intra-MHC microsatellites and haplotypes defined using classical serology. Here, we estimated MHC diversity in a sample of 124 Arabian horses from an endangered strain native to Iran (Persian Asil Arabians), using a validated 10-marker microsatellite panel. In a group of 66 horses related as parent-offspring pairs or half-sibling groups, we defined 51 MHC haplotypes, 49 of which were new. In 47 of the remaining 58 unrelated horses, we could assign one previously identified MHC haplotype, and by default, we gave provisional haplotype status to the remaining constellation of microsatellite alleles. In these horses, we found 21 haplotypes that we had previously defined and 31 provisional haplotypes, two of which had been identified in an earlier study. This gave a total of 78 new MHC haplotypes. The final 11 horses were MHC heterozygotes that we could not phase using information from any of the previously validated or provisional haplotypes. However, we could determine that these horses carried a total of 22 different undefined haplotypes. In the overall population sample, we detected three homozygous horses and one maternally inherited recombinant from 21 informative segregations. Virtually all of the horses tested were MHC heterozygotes, and most unrelated horses (98%) were heterozygous for rare microsatellite-defined haplotypes found less than three times in the sampled horses. This is evidence for a very high level of MHC haplotype variation in the Persian Asil Arabian horse.
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Affiliation(s)
- R Sadeghi
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Animal Science, University of Tehran, Karaj, 4111, Iran
| | | | | | - D C Miller
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Douglas F Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
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Bergmann T, Lindvall M, Moore E, Moore E, Sidney J, Miller D, Tallmadge RL, Myers PT, Malaker SA, Shabanowitz J, Osterrieder N, Peters B, Hunt DF, Antczak DF, Sette A. Peptide-binding motifs of two common equine class I MHC molecules in Thoroughbred horses. Immunogenetics 2017; 69:351-358. [PMID: 28315936 DOI: 10.1007/s00251-017-0978-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/13/2017] [Indexed: 11/28/2022]
Abstract
Quantitative peptide-binding motifs of MHC class I alleles provide a valuable tool to efficiently identify putative T cell epitopes. Detailed information on equine MHC class I alleles is still very limited, and to date, only a single equine MHC class I allele, Eqca-1*00101 (ELA-A3 haplotype), has been characterized. The present study extends the number of characterized ELA class I specificities in two additional haplotypes found commonly in the Thoroughbred breed. Accordingly, we here report quantitative binding motifs for the ELA-A2 allele Eqca-16*00101 and the ELA-A9 allele Eqca-1*00201. Utilizing analyses of endogenously bound and eluted ligands and the screening of positional scanning combinatorial libraries, detailed and quantitative peptide-binding motifs were derived for both alleles. Eqca-16*00101 preferentially binds peptides with aliphatic/hydrophobic residues in position 2 and at the C-terminus, and Eqca-1*00201 has a preference for peptides with arginine in position 2 and hydrophobic/aliphatic residues at the C-terminus. Interestingly, the Eqca-16*00101 motif resembles that of the human HLA A02-supertype, while the Eqca-1*00201 motif resembles that of the HLA B27-supertype and two macaque class I alleles. It is expected that the identified motifs will facilitate the selection of candidate epitopes for the study of immune responses in horses.
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Affiliation(s)
- Tobias Bergmann
- Institut für Virologie, Freie Universität Berlin, 14163, Berlin, Germany
| | - Mikaela Lindvall
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA
| | - Erin Moore
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA
| | - Eugene Moore
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA
| | - John Sidney
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA
| | - Donald Miller
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Rebecca L Tallmadge
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Paisley T Myers
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Stacy A Malaker
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | | | - Bjoern Peters
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.,Department of Pathology, University of Virginia, Charlottesville, VA, 22908, USA
| | - Douglas F Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Alessandro Sette
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA, 92037, USA.
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Kydd JH, Case R, Winton C, MacRae S, Sharp E, Ricketts SL, Rash N, Newton JR. Polarisation of equine pregnancy outcome associated with a maternal MHC class I allele: Preliminary evidence. Vet Microbiol 2016; 188:34-40. [PMID: 27139027 DOI: 10.1016/j.vetmic.2016.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 03/21/2016] [Accepted: 04/04/2016] [Indexed: 01/09/2023]
Abstract
Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy loss and the presence of five common Thoroughbred horse haplotypes of the equine Major Histocompatibility Complex (MHC) was assessed. This involved development of sequence specific, reverse transcriptase polymerase chain reactions and in several mares, measurement of cytotoxic T lymphocyte activity. Of the 46 mares, 10 suffered late gestation pregnancy loss or neonatal foal death, five of which were EHV-1 positive. Maternal factors including age, parity, number of EHV-1 specific vaccinations and the number of days between final vaccination and foaling or abortion were not significantly associated with pregnancy loss. In contrast, a statistically significant association between the presence of the MHC class I B2 allele and pregnancy loss was identified, regardless of the fetus/foal's EHV-1 status (p=0.002). In conclusion, this study demonstrated a significantly positive association between pregnancy loss in Thoroughbred mares and a specific MHC class I allele in the mother. This association requires independent validation and further investigation of the mechanism by which the mare's genetic background contributes to pregnancy outcome.
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Affiliation(s)
- J H Kydd
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
| | - R Case
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | - C Winton
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
| | - S MacRae
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | - E Sharp
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | - S L Ricketts
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | - N Rash
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
| | - J R Newton
- Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Newmarket, Suffolk CB8 7UU, UK.
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Binding of alphaherpesvirus glycoprotein H to surface α4β1-integrins activates calcium-signaling pathways and induces phosphatidylserine exposure on the plasma membrane. mBio 2015; 6:e01552-15. [PMID: 26489864 PMCID: PMC4620472 DOI: 10.1128/mbio.01552-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Intracellular signaling connected to integrin activation is known to induce cytoplasmic Ca2+ release, which in turn mediates a number of downstream signals. The cellular entry pathways of two closely related alphaherpesviruses, equine herpesviruses 1 and 4 (EHV-1 and EHV-4), are differentially regulated with respect to the requirement of interaction of glycoprotein H (gH) with α4β1-integrins. We show here that binding of EHV-1, but not EHV-4, to target cells resulted in a rapid and significant increase in cytosolic Ca2+ levels. EHV-1 expressing EHV-4 gH (gH4) in lieu of authentic gH1 failed to induce Ca2+ release, while EHV-4 with gH1 triggered significant Ca2+ release. Blocking the interaction between gH1 and α4β1-integrins, inhibiting phospholipase C (PLC) activation, or blocking binding of inositol 1,4,5-triphosphate (IP3) to its receptor on the endoplasmic reticulum (ER) abrogated Ca2+ release. Interestingly, phosphatidylserine (PS) was exposed on the plasma membrane in response to cytosolic calcium increase after EHV-1 binding through a scramblase-dependent mechanism. Inhibition of both Ca2+ release from the ER and scramblase activation blocked PS scrambling and redirected virus entry to the endocytic pathway, indicating that PS may play a role in facilitating virus entry directly at the plasma membrane. Herpesviruses are a large family of enveloped viruses that infect a wide range of hosts, causing a variety of diseases. These viruses have developed a number of strategies for successful entry into different cell types. We and others have shown that alphaherpesviruses, including EHV-1 and herpes simplex virus 1 (HSV-1), can route their entry pathway and do so by manipulation of cell signaling cascades to ensure viral genome delivery to nuclei. We show here that the interaction between EHV-1 gH and cellular α4β1-integrins is necessary to induce emptying of ER calcium stores, which induces phosphatidylserine exposure on the plasma membrane through a scramblase-dependent mechanism. This change in lipid asymmetry facilitates virus entry and might help fusion of the viral envelope at the plasma membrane. These findings will help to advance our understanding of herpesvirus entry mechanism and may facilitate the development of novel drugs that can be implemented for prevention of infection and disease.
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Bergmann T, Moore C, Sidney J, Miller D, Tallmadge R, Harman RM, Oseroff C, Wriston A, Shabanowitz J, Hunt DF, Osterrieder N, Peters B, Antczak DF, Sette A. The common equine class I molecule Eqca-1*00101 (ELA-A3.1) is characterized by narrow peptide binding and T cell epitope repertoires. Immunogenetics 2015; 67:675-89. [PMID: 26399241 DOI: 10.1007/s00251-015-0872-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/14/2015] [Indexed: 11/29/2022]
Abstract
Here we describe a detailed quantitative peptide-binding motif for the common equine leukocyte antigen (ELA) class I allele Eqca-1*00101, present in roughly 25 % of Thoroughbred horses. We determined a preliminary binding motif by sequencing endogenously bound ligands. Subsequently, a positional scanning combinatorial library (PSCL) was used to further characterize binding specificity and derive a quantitative motif involving aspartic acid in position 2 and hydrophobic residues at the C-terminus. Using this motif, we selected and tested 9- and 10-mer peptides derived from the equine herpesvirus type 1 (EHV-1) proteome for their capacity to bind Eqca-1*00101. PSCL predictions were very efficient, with an receiver operating characteristic (ROC) curve performance of 0.877, and 87 peptides derived from 40 different EHV-1 proteins were identified with affinities of 500 nM or higher. Quantitative analysis revealed that Eqca-1*00101 has a narrow peptide-binding repertoire, in comparison to those of most human, non-human primate, and mouse class I alleles. Peripheral blood mononuclear cells from six EHV-1-infected, or vaccinated but uninfected, Eqca-1*00101-positive horses were used in IFN-γ enzyme-linked immunospot (ELISPOT) assays. When we screened the 87 Eqca-1*00101-binding peptides for T cell reactivity, only one Eqca-1*00101 epitope, derived from the intermediate-early protein ICP4, was identified. Thus, despite its common occurrence in several horse breeds, Eqca-1*00101 is associated with a narrow binding repertoire and a similarly narrow T cell response to an important equine viral pathogen. Intriguingly, these features are shared with other human and macaque major histocompatibility complex (MHC) molecules with a similar specificity for D in position 2 or 3 in their main anchor motif.
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Affiliation(s)
- Tobias Bergmann
- Institut für Virologie, Freie Universtiät Berlin, 14163, Berlin, Germany
| | - Carrie Moore
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - John Sidney
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Donald Miller
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Rebecca Tallmadge
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Rebecca M Harman
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Carla Oseroff
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Amanda Wriston
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.,Department of Pathology, University of Virginia, Charlottesville, VA, 22904, USA
| | | | - Bjoern Peters
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA
| | - Douglas F Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Alessandro Sette
- Department of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, 92037, USA.
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