Prof. Dr. Petr Chlanda

petr.chlanda@
bioquant.uni-heidelberg.de
Bio­Quant (INF 267)
Phone: +49 6221 54–51231
Fax: +49 6221 54–51480

Cryo-Electron Microscopy of Viral Infection

Projects

We study mem­brane-enveloped RNA virus­es, includ­ing influen­za A virus and oth­er mem­bers of the Orthomyx­oviri­dae fam­i­ly, as well as SARS-CoV­‑2 and Ebo­la virus. Our goal is to under­stand the mol­e­c­u­lar mech­a­nisms of key steps involv­ing virus-host mem­brane inter­ac­tions dur­ing the viral infec­tion cycle. Our research focus­es on virus-medi­at­ed mem­brane fusion, the struc­ture and func­tion of repli­ca­tion organelles, and virus assembly.

These crit­i­cal process­es of viral infec­tion remain poor­ly under­stood at high res­o­lu­tion in the con­text of infect­ed cells. To address this, we use and fur­ther devel­op cryo-elec­tron microscopy (cryo-EM) tech­niques such as cryo-focused ion beam milling (cryo-FIB), in situ cryo-elec­tron tomog­ra­phy (cryo-ET), and cryo-cor­rel­a­tive light and elec­tron microscopy (cryo-CLEM). We also inte­grate oth­er imag­ing meth­ods, includ­ing flu­o­res­cence microscopy and cryo­genic imag­ing mass spec­trom­e­try, to unrav­el the com­plex­i­ties of viral-mem­brane interactions.

1 | Entry and Spread of Influenza A Virus

We specif­i­cal­ly inves­ti­gate hemag­glu­tinin-medi­at­ed mem­brane fusion and the entry of spher­i­cal and fil­a­men­tous influen­za A virus­es. We have devel­oped a cor­rel­a­tive flu­o­res­cence and scan­ning elec­tron microscopy approach that allows us to assess virus mor­phol­o­gy changes dur­ing viral spread. Addi­tion­al­ly, we exam­ine how neu­tral­iz­ing anti­bod­ies and mucins influ­ence the spread of virus­es with dif­fer­ent mor­pholo­gies. This project is fund­ed by SFB1129.

2 | Assembly and vRNP Trafficking in Orthomyxoviridae

We dis­cov­ered that influen­za A virus vRNPs inter­act with hemag­glu­tinin-remod­eled mem­branes, facil­i­tat­ing vRNP clus­ter­ing. We are cur­rent­ly inves­ti­gat­ing vRNP incor­po­ra­tion into bud­ding viri­ons, orches­trat­ed by M1 and M2 pro­teins, in both non-polar­ized and polar­ized cell lines using dif­fer­ent mem­bers of the Orthomyx­oviri­dae family.

3 | SARS-CoV‑2 Replication Organelles and Assembly of Virus-Like Particles

Using cryo-ET, we study SARS-CoV­‑2 assem­bly in a virus-like par­ti­cle sys­tem. We aim to under­stand how assem­bly is orches­trat­ed at the mol­e­c­u­lar lev­el and the roles of indi­vid­ual pro­teins in mem­brane bend­ing. Addi­tion­al­ly, we focus on the struc­tur­al char­ac­ter­i­za­tion of SARS-CoV­‑2 dou­ble-mem­brane vesi­cles and a mol­e­c­u­lar pore. This project is fund­ed by SFB1638.

Selected Publications

Peterl S, Lahr CM, Schnei­der CN, Mey­er J, Podlipen­sky X, Lech­n­er V, Vil­liou M, Eis L, Klein S, Funaya C, Cav­al­can­ti-Adam EA, Graw F, Sel­hu­ber-Unkel C, Rohr K, Chlan­da P. (2025) Mor­phol­o­gy-depen­dent entry kinet­ics and spread of influen­za A virus. EMBO J. doi: 10.1038/s44318-025–00481‑6.

Vall­bracht M, Bod­mer BS, Fis­ch­er K, Makroczy­o­va J, Win­ter SL, Wendt L, Wachsmuth-Melm M, Hoe­nen T, Chlan­da P. (2025) Nucle­o­cap­sid assem­bly dri­ves Ebo­la viral fac­to­ry mat­u­ra­tion and dis­per­sion. Cell. 2025 Feb 6;188(3):704–720.e17. doi: 10.1016/j.cell.2024.11.024.

Zim­mer­mann L, Zhao X, Makroczy­o­va J, Wachsmuth-Melm W, Prasad V, Hensel Z, Barten­schlager R, Chlan­da P. (2023) SARS-CoV­‑2 nsp3 and nsp4 are min­i­mal con­stituents of a pore span­ning repli­ca­tion organelle. Nature Communications,14(1):7894. doi: 10.1038/s41467-023–43666‑5

Zim­mer­mann L, Chlan­da P. Cryo-elec­tron tomog­ra­phy of viral infec­tion — from appli­ca­tions to biosafe­ty. Curr Opin Virol. 2023 Aug;61:101338. doi: 10.1016/j.coviro.2023.101338.

Win­ter SL, Golani G, Loli­ca­to F, Vall­bracht M, Thiya­gara­jah K, Ahmed SS, Lücht­en­borg C, Fack­ler OT, Brüg­ger B, Hoe­nen T, Nick­el W, Schwarz US, Chlan­da P, (2023) The Ebo­la virus VP40 matrix under­goes endo­so­mal dis­as­sem­bly essen­tial for mem­brane fusion, EMBO J. 42(11):e113578. doi: 10.15252/embj.2023113578.

Klein S, Golani G, Loli­ca­to F, Bey­er D, Her­rmann A, Wachsmuth-Melm M, Red­dmann N, Brecht R, Lahr C, Hos­sein­zadeh M, Kolovou A, Schorb M, Schwab Y, Brüg­ger B, Nick­el W, Schwarz US, Chlan­da P, (2023) IFITM3 blocks viral entry by sort­ing lipids and sta­bi­liz­ing hemi­fu­sion, Cell Host&Microbe, S1931-3128(23)0019–9, doi: 10.1016/j.chom.2023.03.005.

Win­ter SL, Chlan­da P, (2021) Dual-axis Vol­ta phase plate cryo-elec­tron tomog­ra­phy of Ebo­la virus-like par­ti­cles reveals actin-VP40 inter­ac­tions, J Struct Biol, 107742. doi: 10.1016/j.jsb.2021.107742.

Klein S, Wim­mer WH, Win­ter SL, Kolovou A, Lake­ta V, Chlan­da P, (2021) Post-cor­re­la­tion on-lamel­la cryo-CLEM reveals the mem­brane archi­tec­ture of lamel­lar bod­ies. Com­mu­ni­ca­tions Biol­o­gy, 2021 Jan 29;4(1):137. doi: 10.1038/s42003-020–01567‑z.

Klein S, Wachsmuth-Melm M, Win­ter SL, Kolovou A, Chlan­da P. (2021) Cryo-cor­rel­a­tive light and elec­tron microscopy work­flow for cryo-focused ion beam milled adher­ent cells. Meth­ods Mol Biol. Cor­rel­a­tive Light and Elec­tron Microscopy, IV Vol­ume 162, Chap­ter 12.

Klein S, Cortese M, Win­ter SL, Wachsmuth-Melm M, Neufeldt CJ, Cerikan B, Stan­i­fer ML, Boulant S, Barten­schlager R, Chlan­da P. (2020) SARS-CoV­‑2 struc­ture and repli­ca­tion char­ac­ter­ized by in situ cryo-elec­tron tomog­ra­phy. Nature Com­mu­ni­ca­tions, 11, 5885 doi.org/10.1038/s41467-020–19619‑7.