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Jennifer Juno @jenjuno.viralvaxlab.com · 28/04/2026

👩‍🔬 Viral Vax Lab is looking for a post-doc! We have a junior postdoctoral position available for someone who is excited about CD4 T cells, B cells, and vaccines against infectious disease. Come join us at UniMelb and the Doherty Institute! unimelb.wd105.myworkdayjobs.com/en-GB/UoM_Ex...

unimelb.wd105.myworkdayjobs.com

Research Officer

Position Number: JR-012330 Role type: Full Time; Fixed Term until May 2027 Location: Parkville Faculty: Medicine, Dentistry and Health Sciences (MDHS) Department: Microbiology and Immunology Salary: L...

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

This was fantastic work from Mitchell Zheng and Hyon-Xhi Tan working with the @viralvaxlab.bsky.social team, including myself and @wheatleyak.viralvaxlab.com. Thanks to everyone who contributed @thedohertyinst.bsky.social!

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

We found that TFH differentiation can be tuned by manipulating peptide-MHCII availability on B cells - increasing HA91 presentation on a larger pool of B cells improved stem-HA91 immunogenicity, while decreasing the stem-SMARTA dose selectively reduced TFH numbers without impacting total CD4 priming

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

We used tetramers to confirm that both HA91 and SMARTA peptides were processed and primed similar numbers of CD4 T cells. What differed was their TFH differentiation - HA91-specific T cells failed to develop into a CD90low GC TFH population. As a result, no stem-specific GC formed.

Number of epitope-specific CD4 T cells determined by tetramer staining

Number and phenotype of tetramer-specific TFH cells

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

We next engineered variants of our stem antigen ‘tagged’ with one of these peptides or a well known control epitope – OTII or SMARTA. Some of the peptides were able to rescue the immunogenicity of the stem protein (like HA523 and GP61). Surprisingly, though, the dominant HA91 peptide had no impact.

Design and primary immunogenicity of stem-peptide antigens

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

But what about recombinant protein immunogens? To what extent can individual CD4 epitopes rescue or tune immunogenicity? We started by mapping the CD4 epitopes in PR8 HA, and found a highly dominant peptide (HA91) as well as three subdominant peptides.

Map of immunogenic peptides in influenza HA

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

It turns out that after repeated boosting, we could find extremely subdominant ferritin-specific CD4 cells (but nothing for stem!) - meaning that these rare responses can support a GC reaction when the antigen is arrayed on a nanoparticle

Proliferation of ferritin-specific CD4 T cells following 3 doses of stem-ferritin nanoparticle vaccination

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

So how can we make stem more immunogenic? Up first: stem-ferritin nanoparticles, which elicit a strong IgG response after one immunisation in the mice. This was a bit of a mystery to us, since neither the stem protein nor ferritin nanoparticle contain detectible CD4 epitopes in BL/6 mice.

Immunogenicity of stem versus stem-ferritin nanoparticles in BL/6 mice

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

We focused on the influenza HA stem antigen as an example of a small vaccine immunogen with limited CD4 help. In fact, the stem protein has no CD4 epitopes in BL/6 mice at all, so it serves as a model of a ‘help-less’ immunogen that doesn't elicit a primary antibody response.

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/03/2026

TL;DR: Immunodominant epitopes aren't always helpful - some polyclonal T cell populations are poorly recruited into the GC, even if they dominate the CD4 repertoire. Conversely, rare and subdominant CD4s can drive a GC if antigen is presented on a nanoparticle (likely enhancing BCR signalling)

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Reposted by Jennifer Juno

Angie Rasmussen @angierasmussen.bsky.social · 08/09/2025

I am always so impressed by @marioskoutsakos.viralvaxlab.com’s elegant work on influenza B virus vaccines. Congratulations, Marios, on your Early Career Researcher Award! #19vaccinecongress

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Reposted by Jennifer Juno

Dr Elissa Deenick @elissadeenick.bsky.social · 10/07/2025

The Precision Immunology and Immune Biotherapies Programs at the Garvan Institute are looking for new Faculty members. Come join us and work with amazing scientists in an amazing place @labphan.bsky.social @garvaninstitute.bsky.social www.nature.com/naturecareer...

nature.com

Garvan Faculty Member - Sydney (LGA), New South Wales (AU) job with The Garvan Institute | 12841341

The Garvan Institute invites applicants for Faculty-level positions in the Immune Biotherapies and Precision Immunology Programs.

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Reposted by Jennifer Juno

Dr. Dawn Bowdish @msmacrophage.bsky.social · 06/06/2025

Publication alert: "No evidence of immune exhaustion after repeated SARS-CoV-2 vaccination in vulnerable and healthy populations" ‪@natcomms.nature.com‬ The backstory is particularly interesting-it's a tale of the conflicting needs of scientists & decision makers in times of disinformation ....1/n

rdcu.be

No evidence of immune exhaustion after repeated SARS-CoV-2 vaccination in vulnerable and healthy populations

Nature Communications - Repeated vaccination is needed to maintain high levels of SARS-CoV-2 immunity in vulnerable populations, but there is concern that it could lead to immune exhaustion. Here,...

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Jennifer Juno @jenjuno.viralvaxlab.com · 29/04/2025

Fantastic work from @labphan.bsky.social and @mlmunier.bsky.social combining mouse models and clinical studies to understand B cell recall following booster vaccination. Check out the paper and thread below! ⤵️

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Jennifer Juno @jenjuno.viralvaxlab.com · 26/04/2025

Check out the latest from @viralvaxlab.bsky.social postdoc Wen Shi Lee, developing monoclonal antibodies that neutralise the NL63 coronavirus!

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Jennifer Juno @jenjuno.viralvaxlab.com · 04/04/2025

Great new story exploring how B cells can recognise glycans (and still get T cell help!) from @precisionvaxlab.bsky.social and team!

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/03/2025

What do you need them for, Julie? We might have other lines that would work for your experiments.

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Reposted by Jennifer Juno

JCI insight @insight.jci.org · 28/02/2025

Should you get the COVID mRNA and flu vaccines in the same or opposite arms? Randomised trial by Lee, Selva, et al. suggests it is preferable to administer the vaccines at different sites. buff.ly/3D4gX95

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Jennifer Juno @jenjuno.viralvaxlab.com · 28/02/2025

Unfortunately, Melbourne isn't going to be quite as seamless of an experience...

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Reposted by Jennifer Juno

Adrian Liston @labliston.bsky.social · 03/02/2025

If any American immunologists want to write an op-ed for @immunolcellbiol.bsky.social on the impact of the new executive orders, please contact me

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

9/9 Thanks to all our collaborators who helped out with the study, and congrats to Mitchell, who persevered through a lot of possible activation marker combinations!

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

8/9 In short, we suggest in vitro stimulation activates ag-specific T cells, which secrete cytokines and activate Treg and Th17/22 cells. Without careful phenotyping, all of these cells can get picked up as AIM+, accounting for the Th17-like memory cells found in many virus-specific AIM datasets.

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

7/9 Mitch sorted tetramer-specific cells, labelled them, and added them back into PBMC before stimulating with the relevant peptide. He was able to show that ag-specific CD4 cells downregulate CXCR4 while upregulating 4-1BB/CD137, giving us a more accurate way to define antigen specificity.

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

6/9 Unfortunately, these cytokine-activated cells upregulated almost all of the AIM markers we normally use. One difference, however, appeared to be CXCR4. TCR-mediated activation efficiently downregulates CXCR4 expression, while cytokine-mediated activation has much less of an impact.

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

5/9 Using RNAseq and confirmatory FACS, Mitch showed that CD39+ Tregs and Th17/Th22 cells expressing CCR6 and high levels of CD26 were being activated through the transwell via a mechanism involving IL-2. These same subsets are also found during standard peptide-based AIM assays.

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

4/9 Possibly! In a transwell assay, anti-CD3/CD28 stimulation can drive T cells in an adjacent chamber to express common activation markers (CD25, OX-40, 4-1BB, CD40L). All of these responding cells had a memory phenotype, and were strongly enriched for CCR6 expression.

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

3/9 Mitch ruled out a few options: CD4 cells don’t upregulate CCR6 during peptide stimulation, and the AIM+ CCR6+ cells don’t usually contain clonally expanded TCRs. Does that mean that AIM assays might be picking up cases of TCR-independent activation?

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

2/9 Recently, though, we’ve been bothered by something we couldn’t explain: we find a lot of Th17-like, CCR6+ SARS-CoV-2 spike-specific CD4 T cells in our AIM assays, but we never see these cells when we use spike-specific class II tetramers. Why?

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Jennifer Juno @jenjuno.viralvaxlab.com · 20/12/2024

As a first #ImmunoSky post, I’m excited to share our latest pre-print, by the fantastic Mitchell Zheng! www.biorxiv.org/content/10.1... Our group is interested in virus-specific CD4 T cells, which means we often use in vitro stimulations (like the AIM assay) to find our cells of interest. 🧵 1/9

biorxiv.org

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Jennifer Juno @jenjuno.viralvaxlab.com · 03/12/2024

Congrats Danika, great to see!

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Reposted by Jennifer Juno

Marc Veldhoen @marcveld.bsky.social · 25/11/2024

Sectarianism in immunology. (highly specific for immunologists, all credit to @pedromics on X) 1/8

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