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Arjun Aditham @arjunine.bsky.social · May 20

Our rabies glycoprotein is now online in Cell Host & Microbe (open access): www.cell.com/cell-host-mi...

In the revised manuscript, we added Figures S4 and S5, which contain further validation of candidate pre-fusion stabilization mutations for rabies G we highlighted in the preprint.

Deep mutational scanning of rabies glycoprotein defines mutational constraint and antibody-escape mutations

Rabies virus causes thousands of human deaths annually and is the target of post-exposure prophylactic development. Aditham et al. use a pseudovirus platform to measure how all mutations to the rabies...

www.cell.com

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Arjun Aditham @arjunine.bsky.social · Mar 28

Congratulations @pollyfordyce.bsky.social !! Super well-deserved :)

Polly Fordyce @pollyfordyce.bsky.social · Mar 27

I am honored to be elected into the 2025 class of AAAS Fellows! It is surreal to see my name in the list.
I am very grateful to lab members over the last 10 years & to Aaron Streets & Jason Sello for the chance to co-launch the Next Gen Symposium (1/2).
news.stanford.edu/stories/2025...

Four Stanford faculty named AAAS Fellows

The faculty are among 471 new fellows of the American Association for the Advancement of Science.

news.stanford.edu

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Arjun Aditham @arjunine.bsky.social · Dec 20

Thank you! I hope it will be a helpful platform for the research community.

Arjun Aditham @arjunine.bsky.social · Dec 19

As noted, please navigate to dms-vep.org/RABV_Pasteur... to view all of the data in an interactive format.

Deep mutational scanning of rabies G (Pasteur strain)

Pseudovirus deep mutational scanning to measure how rabies G mutations affect cell entry and escape from a panel of monoclonal antibodies

dms-vep.org

Arjun Aditham @arjunine.bsky.social · Dec 19

A huge thank you to Jesse, Caelan, Caleb, Naveen Jasti and @neilpking.bsky.social (especially bringing me up to speed on this protein!). Also thank you to the Bloom Lab for the valuable feedback and steadfast support to bring this project up off the ground.

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Arjun Aditham @arjunine.bsky.social · Dec 19

Overall, I really enjoyed using DMS to study antibodies for prospective breadth as @jbloomlab.bsky.social describes extensively. I’m also excited by the mechanistic hypotheses this study generates, a cause near and dear to my heart.

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Arjun Aditham @arjunine.bsky.social · Dec 19

Note that Figure 5 goes into more details about comparing escape sites versus antibody-G contact sites for structures that have been solved by others.

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Arjun Aditham @arjunine.bsky.social · Dec 19

CTB012 (Chao et al. doi.org/10.1371/jour...) escape sites are only contiguous in pre-fusion rabies G. Also, escape mutations are at H270, which is mutated in a vaccine candidate (doi.org/10.1016/j.ch... and doi.org/10.1016/j.va...)

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Arjun Aditham @arjunine.bsky.social · Dec 19

Can DMS insights antibodies lacking structures in complex? RVC68 was discovered (Debenedicitis, et al doi.org/10.15252/emm...) to bind a novel site and is very broad-spectrum against lyssaviruses, and here we’ve mapped it to the base of the fusion domain.

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Arjun Aditham @arjunine.bsky.social · Dec 19

We also looked at several antibodies that don’t have structures in complex with G. Getting structures of these complexes is a major challenge. Even fewer have full rabies G, many others use fragments of rabies G for structures. (Too many to cite here—sorry!).

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Arjun Aditham @arjunine.bsky.social · Dec 19

Of course, with cell entry measurements, these are hypotheses, but I hope will provide additional useful avenues for biochemically characterizing rabies G and engineering rabies vaccines, for example by trying to destabilize the extended intermediate.

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Arjun Aditham @arjunine.bsky.social · Dec 19

We saw other hydrophobic residues cluster in the extended intermediate, and most only tolerate hydrophobic substitutions. A couple of these are solvent-facing in the pre-fusion conformation, suggesting hydrophobicity requirements originate from the extended intermediate.

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Arjun Aditham @arjunine.bsky.social · Dec 19

When looking at the extended intermediate, we recapitulate prior information of some known contacts. But we also observe other residues that are also highly mutationally constrained. They may play a role in scaffolding known important residues in this conformation.

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Arjun Aditham @arjunine.bsky.social · Dec 19

We wondered if our DMS could help here and are grateful to have access to both pre-fusion and extended intermediate structures. Both conformations require substantial rearrangements, and some residues form contacts in the extended intermediate. (Prefusion PDB: 7U9G, Extended PDB: 6LGW)

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Arjun Aditham @arjunine.bsky.social · Dec 19

As noted, rabies G exchanges between pre-fusion and extended conformation states, making vaccine development difficult. Stabilizing pre-fusion rabies G is actively studied (eg doi.org/10.1016/j.ch... and doi.org/10.1126/scia...).

Redirecting

doi.org

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Arjun Aditham @arjunine.bsky.social · Dec 19

Thank you to @jbloomlab.bsky.social for the opportunity to work on/lead this study. We employ a pseudovirus system that is non-replicative and a safe way to study mutations to rabies G. Jesse already authored a very nice overarching summary, so I’ll zoom in on a couple points.

Bloom lab @jbloomlab.bsky.social · Dec 18

In new study, we measure how all mutations to rabies G affect cell entry & antibody neutralization

Sheds light on constraints on type III fusion proteins, suggests ways to stabilize G vaccine antigens, and quantifies antibody robustness to rabies variation

www.biorxiv.org/content/10.1...

Deep mutational scanning of rabies glycoprotein defines mutational constraint and antibody-escape mutations

Rabies virus causes nearly 60,000 human deaths annually. Antibodies that target the rabies glycoprotein (G) are being developed as post-exposure prophylactics, but mutations in G can render such antib...

www.biorxiv.org

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Arjun Aditham @arjunine.bsky.social · Dec 19

As noted, please navigate to dms-vep.org/RABV_Pasteur... to view all of the data in an interactive format.

Arjun Aditham @arjunine.bsky.social · Dec 19

A huge thank you to Jesse, Caelan, Caleb, Naveen Jasti and @neilpking.bsky.social (especially bringing me up to speed on this protein!). Also thank you to the Bloom Lab for the valuable feedback and steadfast support to bring this project up off the ground.

1

Arjun Aditham @arjunine.bsky.social · Dec 19

I really enjoyed using DMS to study antibodies for prospective breadth as @jbloomlab.bsky.social describes extensively. I’m also excited by the mechanistic hypotheses this study can generate, a cause near and dear to my heart.

1

Arjun Aditham @arjunine.bsky.social · Dec 19

(Figure 5 goes into more details about comparing escape sites versus antibody-G contact sites for structures that have been solved by others.)

1

Arjun Aditham @arjunine.bsky.social · Dec 19

CTB012 (Chao et al. doi.org/10.1371/jour...) escape sites are only contiguous in pre-fusion rabies G. Also, escape mutations are at H270, which is mutated in a vaccine candidate (doi.org/10.1016/j.ch... and doi.org/10.1016/j.va...)

1

Arjun Aditham @arjunine.bsky.social · Dec 19

Can DMS insights antibodies lacking structures in complex? RVC68 was discovered (Debenedicitis, et al doi.org/10.15252/emm...) to bind a novel site and is very broad-spectrum against lyssaviruses, and here we’ve mapped it to near the base of the fusion domain.

1

Arjun Aditham @arjunine.bsky.social · Dec 19

We also looked at several antibodies that don’t have structures in complex with G. Getting structures of these complexes is a major challenge. Even fewer have full rabies G, many others use fragments of rabies G for structures. (Too many to cite here—sorry!).

1

Arjun Aditham @arjunine.bsky.social · Dec 19

Of course, with cell entry measurements, these are hypotheses, but I hope will provide additional useful avenues for mechanistically characterizing rabies G and engineering rabies vaccines, for example by trying to destabilize the extended intermediate and bias the pre-fusion state.

1