Within-Host Spatiotemporal Dynamics of Plant Virus Infection at the Cellular Level

English version České info

A multicellular organism is not a monolayer of cells in a flask; it is a complex, spatially structured environment, offering both challenges and opportunities for viruses to thrive. Whereas virus infection dynamics at the host and within-cell levels have been documented, the intermediate between-cell level remains poorly understood. Here, we used flow cytometry to measure the infection status of thousands of individual cells in virus-infected plants. This approach allowed us to determine accurately the number of cells infected by two virus variants in the same host, over space and time as the virus colonizes the host. We found a low overall frequency of cellular infection (<0.3), and few cells were coinfected by both virus variants (<0.1). We then estimated the cellular contagion rate (R), the number of secondary infections per infected cell per day. R ranged from 2.43 to values not significantly different from zero, and generally decreased over time. Estimates of the cellular multiplicity of infection (MOI), the number of virions infecting a cell, were low (<1.5). Variance of virus-genotype frequencies increased strongly from leaf to cell levels, in agreement with a low MOI. Finally, there were leaf-dependent differences in the ease with which a leaf could be colonized, and the number of virions effectively colonizing a leaf. The modeling of infection patterns suggests that the aggregation of virus-infected cells plays a key role in limiting spread; matching the observation that cell-to-cell movement of plant viruses can result in patches of infection. Our results show that virus expansion at the between-cell level is restricted, probably due to the host environment and virus infection itself.

Vyšlo v časopise: Within-Host Spatiotemporal Dynamics of Plant Virus Infection at the Cellular Level. PLoS Genet 10(2): e32767. doi:10.1371/journal.pgen.1004186
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1004186

Souhrn

Zdroje

1. GrenfellBT, PybusOG, GogJR, WoodJLN, DalyJM, et al. (2004) Unifying the epidemiological and evolutionary dynamics of pathogens. Science 303: 327–332.

2. MideoN, AlizonS, DayT (2008) Linking within- and between-host dynamics in the evolutionary epidemiology of infectious diseases. Trends Ecol Evol 23: 511–517.

3. MartínezF, SardanyésJ, ElenaSF, DaròsJA (2011) Dynamics of a plant RNA virus intracellular accumulation: Stamping machine vs. geometric replication. Genetics 188: 637–646.

4. CuevasJM, MoyaA, SanjuánR (2005) Following the very initial growth of biological RNA viral clones. J Gen Virol 86: 435–443.

5. DoljaVV, McBrideHJ, CarringtonJC (1992) Tagging of plant potyvirus replication and movement by insertion of β-glucuronidase into the viral polyprotein. Proc Natl Acad Sci USA 89: 10208–10212.

6. MetcalfCJE, GrahamAL, HuijbenS, BarclayVC, LongGH, et al. (2011) Partitioning regulatory mechanisms of within-host malaria dynamics using the effective propagation number. Science 333: 984–988.

7. González-JaraP, FraileA, CantoT, García-ArenalF (2009) The multiplicity of infection of a plant virus varies during colonization of its eukaryotic host. J Virol 83: 7487–7494.

8. ZwartMP, DaròsJA, ElenaSF (2012) Effects of potyvirus effective population size in inoculated leaves on viral accumulation and the onset of symptoms. J Virol 86: 9737–9747.

9. GutiérrezS, YvonM, PirollesE, GarzoE, FereresA, et al. (2010) Dynamics of the multiplicity of cellular infection in a plant virus. PLoS Pathog 6: e1001113.

10. LiHY, RoossinckMJ (2004) Genetic bottlenecks reduce population variation in an experimental RNA virus population. J Virol 78: 10582–10587.

11. SacristánS, MalpicaJM, FraileA, García-ArenalF (2003) Estimation of population bottlenecks during systemic movement of Tobacco mosaic virus in tobacco plants. J Virol 77: 9906–9911.

12. BaldJG (1937) The use of numbers of infections for comparing the concentration of plant virus suspensions I. Dilution experiments with purified suspensions. Ann Appl Biol 24: 33–55.

13. MiyashitaS, KishinoH (2010) Estimation of the size of genetic bottlenecks in cell-to-cell movement of Soil-borne wheat mosaic virus and the possible role of the bottlenecks in speeding up selection of variations in trans-acting genes or elements. J Virol 84: 1828–1837.

14. ZwartMP, DaròsJA, ElenaSF (2011) One is enough: In vivo effective population size is dose-dependent for a plant RNA virus. PLoS Pathog 7: e1002122.

15. LafforgueG, TromasN, ElenaSF, ZwartMP (2012) Dynamics of the establishment of systemic Potyvirus infection: Independent yet cumulative action of primary infection sites. J Virol 86: 12912–12922.

16. González-JaraP, FraileA, CantoT, García-ArenalF (2013) Author's correction: The multiplicity of infection of a plant virus varies during colonization of its eukaryotic host. J Virol 87: 2374.

17. ZwartMP, TromasN, ElenaSF (2013) Model-selection-based approach for calculating cellular multiplicity of infection during virus colonization of multi-cellular hosts. PLoS ONE 8: e64657.

18. GutiérrezS, YvonM, PirollesE, GarzoE, FereresA, et al. (2012) Circulating virus load determines the size of bottlenecks in viral populations progressing within a host. PLoS Pathog 8: e1003009.

19. DietrichC, MaissE (2003) Fluorescent labelling reveals spatial separation of Potyvirus populations in mixed infected Nicotiana benthamiana plants. J Gen Virol 84: 2871–2876.

20. Sankara RaoK, PrakashAH (1995) A simple method for the isolation of plant protoplasts. J Biosci 20: 645–655.

21. ZwartMP, WillemsenA, DaròsJA, ElenaSF (in press) Experimental evolution of pseudogenization and gene loss in a plant RNA virus. Mol Biol Evol 31(1): 121–134.

22. RobertsAG, CruzSS, RobertsIM, PriorDAM, TurgeonR, et al. (1997) Phloem unloading in sink leaves of Nicotiana benthamiana: Comparison of a fluorescent solute with a fluorescent virus. Plant Cell 9: 1381–1396.

23. BarlowND (1991) A spatially aggregated disease host model for bovine TB in New Zealand possum populations. J Appl Ecol 28: 777–793.

24. BarlowND (2000) Non-linear transmission and simple models for bovine tuberculosis. J Animal Ecol 69: 703–713.

25. MonsionB, FroissartR, MichalakisY, BlancS (2008) Large bottleneck size in Cauliflower mosaic virus populations during host plant colonization. PLoS Pathog 4: e1000174.

26. HallJS, FrenchR, HeinGL, MorrisTJ, StengerDC (2001) Three distinct mechanisms facilitate genetic isolation of sympatric Wheat streak mosaic virus lineages. Virology 282: 230–236.

27. WaterhousePM, WangMB, LoughT (2001) Gene silencing as an adaptive defence against viruses. Nature 411: 834–842.

28. VoinnetO, VainP, AngellS, BaulcombeDC (1998) Systemic spread of sequence-specific transgene RNA degradation in plants is initiated by localized introduction of ectopic promoterless DNA. Cell 95: 177–187.

29. PaschalidisAP, Roubelakis-AngelakisKA (2005) Spatial and temporal distribution of polyamine levels and polyamine anabolism in different organs/tissues of the tobacco plant. Correlations with age, cell division/expansion, and differentiation. Plant Physiol 138: 142–152.

30. KeelingMJ (1999) The effects of local spatial structure on epidemiological invasions. Proc R Soc B 266: 859–867.

31. van BaalenM, SabelisMW (1995) The milker-killer dilemma in spatially structured predator-prey interactions. Oikos 74: 391–400.

32. BootsM, MealorM (2007) Local interactions select for lower pathogen infectivity. Science 315: 1284–1286.

33. BedoyaLC, DaròsJA (2010) Stability of Tobacco etch virus infectious clones in plasmid vectors. Virus Res 149: 234–240.

34. NagaiT, IbataK, ParkES, KubotaM, MikoshibaK, et al. (2002) A variant of yellow fluorescent protein with fast and efficient maturation for cell-biological applications. Nat Biotechnol 20: 87–90.

35. SubachOM, GundorovIS, YoshimuraM, SubachFV, ZhangJ, et al. (2008) Conversion of red fluorescent protein into a bright blue probe. Chem Biol 15: 1116–1124.

36. CarrascoP, DaròsJA, Agudelo-RomeroP, ElenaSF (2007) A real-time RT-PCR assay for quantifying the fitness of Tobacco etch virus in competition experiments. J Virol Meth 139: 181–188.

37. MajerE, DaròsJA, ZwartMP (2013) Stability and fitness impact of the visually discernable Rosea1 marker in the Tobacco etch virus genome. Viruses 5: 2153–2168.

38. KunkelLO (1934) Studies on acquired immunity with tobacco and aucuba mosaic. Phytopathology 24: 437–66.

39. ThungTH (1928) Physiologisch onderzoek met betrekking tot het virus der bladrolziekte van de aardappel-plant, Solanum tuberosum L. Tijdschrift over Plantenziekten 34: 1–74.

40. Olkin I, Gleser, L.J. Derman, C. (1994) Probability Models and Applications, 2nd ed. New York: Macmillan. 575 p.

41. WrightS (1931) Evolution in Mendelian populations. Genetics 16: 97–159.