Publication: Reassuring humoral and cellular immune responses to SARS-CoV-2 vaccination in participants with systemic sclerosis

Benoit JM, Breznik JA, Huynh A, Cowbrough B, Baker B, Heessels L, Lodhi S, Yan E, Bhakta H, Clare R, Nazy I, Bramson JL, Larché MJ, Bowdish DM. Reassuring humoral and cellular immune responses to SARS-CoV-2 vaccination in participants with systemic sclerosis. Immunol Lett. 2024 Sep 19;270:106929. doi: 10.1016/j.imlet.2024.106929. 

Below is a Bluesky thread that summarizes and explains our manuscript. Click here to read it on Bluesky.

New publication alert! “Reassuring humoral and cellular immune responses to SARS-CoV-2 vaccination in participants with systemic sclerosis” Read on to learn why we did this study and why it is important. 1/n https://www.sciencedirect.com/science/article/pii/S0165247824001032?via%3Dihub

https://bsky.app/profile/msmacrophage.bsky.social/post/3l5zdipjxwe2o

Systemic Sclerosis(SSc) is a rare autoimmune disorder that causes fibrosis of the organs. Because it is caused an immune system gone awry, patients and their doctors were concerned that their immune systems might not respond to the vaccine and leave them less protected 2/n

Because SSC is an autoimmune condition, people generally take immunosuppressive drugs, which can also lead to lower vaccine responses and higher risk of infection. We investigated whether antibody or T cell responses to vaccination were affected in SSC. 3/n

Good news! People with SSC made the same amount of antibodies to the receptor binding domain of the Spike protein (i.e, the bit of the virus that the virus uses to get into us) after their second, third, and fourth SARS-CoV-2 vaccinations. 4/n

More good news! T cell responses to vaccines are thought to help with severe disease and may offer some cross-variant protection. Following the second, third, and fourth SARS-CoV-2 vaccinations, participants with SSc had T cell responses = those without SSC. 5/n

For the immunology geeks: People living with SSc have elevated levels of serum cytokines associated with T cell differentiation. Could this change Th1/2/17/reg mix posts vaccination? Nope. 6/n

Caveat#1: This is a small study (because a rare disease) and we couldn’t investigate all the different drugs that people are on. For more info on how drugs affect vaccination responses see our other studies 7/n https://acrjournals.onlinelibrary.wiley.com/doi/full/10.1002/acr2.11697

Caveat #2: This is very much a comparison of the quantity of immune responses, not the quality. There could still be qualitative differences in immune responses that we didn’t catch but… 8/n

…even though there is very little data on whether SSC is associated with higher infection risk or poorer outcomes what little exists doesn’t find a massive difference compared to the general population 9/n https://acrjournals.onlinelibrary.wiley.com/doi/full/10.1002/acr.25226

Take home message #1: Participants with SSc mount similar responses to SARS-CoV-2 vaccination as controls who do not have autoimmune conditions. 10/n

Take home message #2: Many ppl with autoimmune conditions are afraid that vaccination is unsafe for them because they know their immune system is a bit wonky. It is not the disease that affects immune responses, rather it’s some, not all, drugs at some, not all, doses. 11/n

Thanks to emerging leader & 1st author Jenna Benoit (graduating & looking for a job next year – hint), rheumatologist extraordinaire, Dr. Maggie Larche, cellular immunologist Dr. J. Breznik & J Bramson, team Antibody (Nazy, Huynh) & with special thanks to…..12/n

….our participants. People with SSC often have skin changes which makes blood draws especially hard. Thank you for your commitment to our study and huge props to our exceptional phlebotomist/RC Braeden Cowbrough – our unsung hero. 13/n Fin.

Publication: Neutrophil-mediated innate immune resistance to bacterial pneumonia is dependent on Tet2 function

https://bsky.app/profile/msmacrophage.bsky.social/post/3kubwknbcts2e
Click here for the full thread from Bluesky highlighting the major findings of the paper.
To see the full paper click here:
To see the commentary click here:



Bluesky thread:

Let me tell you about the #BowdishLab & friend’s most recent paper “Neutrophil-mediated innate immune resistance to bacterial pneumonia is dependent on Tet2 function”, led by Dr. C. Quin (now at @uniofaberdeen.bsky.social) @jclinical-invest.bsky.social https://www.jci.org/articles/view/171002
Tet2 is gene that is involved with methylating genes and therefore changing gene expression. Sometimes spontaneous mutations of Tet2 in hematopoetic stem cells (HSC) occur. These mutants tend to produce more myeloid cells (monocytes/neutrophils).
These myeloid producing HSCs tend to be more fit in the aging bone marrow (Darwinian survival of the fittest) and overtime, more and more of your myeloid cells are made from these Tet2 mutant clones.
In extreme cases this can lead to myelodysplastic disorders or cancer, but sub-clinical CHIP or clonal hematopoeisis of indeterminant potential occurs in many older adults.
People with CHIP (i.e., too many of their myeloid cells are made from Tet2 mutant progenitors) are prone to all sorts of conditions (e.g., heart disease) and pneumonia. We hypothesized that pneumonia risk might be due to changes in innate immune/myeloid cell function.
Mice defective in Tet2 did very poorly during Streptococcus pneumoniae infection (the most common cause of community acquired pneumonia in older adults), because their neutrophils were less able to kill bacteria.
We are excited about this @jclinical-invest.bsky.social publication because it is the first mechanistic explanation for the increased risk of pneumonia in CHIP. Generally CHIP is thought to affect macrophage function, but it clearly affects neutrophil gene expression & function as well.
Many thanks to Dr. Elsa Bou Ghahem for her most excellent Commentary https://www.jci.org/articles/view/181064 and for the great editorial & reviewer experience @jclinical-invest.bsky.social
Research Team:Candice Quin, Erica N. DeJong, Elina K. Cook, Yi Zhen Luo, Caitlyn Vlasschaert, Sanathan Sadh, Amy J.M. McNaughton, Marco M. Buttigieg, Jessica A. Breznik, Allison E. Kennedy, Kevin Zhao, Jeffrey Mewburn, Kimberly J. Dunham-Snary, Charles C.T. Hindmarch, Alexander G. Bick, Stephen L. Archer, Michael J. Rauh, Dawn M.E. Bowdish

Publication: “Immunomodulatory drugs have divergent effects on humoral and cellular immune responses to SARS-CoV-2 vaccination in people living with rheumatoid arthritis”

Jenna Benoit (PhD candidate) has published her first, first author paper characterizing how immune responses to vaccination differ in people living with rheumatoid arthritis. We found some interesting new drug-immune interactions.

See the full paper here.

See thread here: https://bsky.app/profile/msmacrophage.bsky.social/post/3kh2uswvqtm2u

or below….

New paper alert! @jennabenoit.bsky.social and team studied COVID-19 vaccinations in people living with rheumatoid arthritis who are on immunosuppressive drugs and found some interesting, and to our knowledge, unknown effects of specific drugs 1/n

Almost all studies of vaccine immunogenicity (i.e., how strong an immune response is to a vaccine) focus on antibody responses. Measuring the amount of antibodies produced is cheap and (relatively) easy; however, in the Omicron-era these are less predictive of protection than you might think 2/n

When investigating anti-receptor binding domain (RBD) antibodies @jennabenoit.bsky.social and team found that -unsurprisingly- people living with RA and men had lower antibody responses (men have lower antibody responses to vaccination in general), and people with COVID had higher responses (i.e., that hybrid immunity you’ve heard so much about) 3/n

What caused these lower antibody responses? DMARDs (disease modifying anti-rheumatic drugs),and anti-TNF were not associated with lower antibody levels, the effect of steroids was not significant, but costimulation inhibitors reduced antibody levels 4/n

Important caveat: The effect of co-stimulation inhibitors was about the same as being a biologic male, so whether this reduction is associated with increased risk of infection or not is not something we can comment on 5/n.

We didn’t see an effect of drugs on neutralizing antibodies (i.e., antibodies that bind the virus really well and prevent it from entering us), but we did not have enough people on some of the drugs to really investigate this 6/n.

My favourite part: CD4+ and CD8+ T cell responses to vaccination are much, much harder to measure (each dot on the graph costs about $350 and 3+ hrs of time – hence the ‘team’ I keep mentioning) but we know that they are important for preventing infection.7/n

We found that people living with RA had lower CD4+ T cell responses (= ‘helper’ cells that support many aspects of the immune response to infection & vaccination), those who had had COVID were higher – more of that hybrid immunity you’ve heard about. 8/n

BUT even though we had a small number of people on JAK inhibitors, those who were on them had markedly lower CD4+ responses. The effect of co-stimulation inhibitors was not as apparent – but again low numbers of participants so hard to say. 9/n

Speculative side note: We use influenza vaccine as a control. Everyone has had exposure as kids so this measures a memory response made prior to having been vaccinated. Co-stim inhibitors don’t affect influenza but JAK inhibitors do – therefore no defect in pre-drug immune responses? 10/n

CD8+ T cell responses (‘killers’ of virus infected cells), were higher in men (previously known), and didn’t seem to be lower in most drugs, except maybe steroids. 11/n

Caveats: Our study was small and due to the fact we were measuring 1,2,3 doses, we were recruiting fast and furious and didn’t capture as many people on some of the drugs as we would have liked,so all results need to be replicated. 12/n

Clinical relevance: Some of these drugs are associated with increased risk of severe disease (see text for references) and by learning which aspects of the immune response they affect, we learn which aspects of the immune response are required for a successful vaccine. 13/n

Deepest appreciation for our research participants, the Canadian Arthritis Patient Alliance (see website for talks on this topic), the SUCCEED investigator team, our technical staff, fundign from the Public Health Agency of Canada, and you for reading to 14/n

How do you balance productivity & psychological safety in a lab? by Dr. Bowdish and others.

Cell Systems asks group leaders how they foster mutually reinforcing research productivity and psychological safety in their teams. Dr. Bowdish and others reflect on this question here…

Publication: Age-associated Inflammation alters the aging trajectory.

This article is written for lay/broad audiences and describes what age-associated inflammation is and why it may be key to healthy/unhealthy aging.

White paper: “Paving The Way For Immunization Innovation” with the Lung Association Ontario

Publication: Myeloid-Derived Suppressor Cells in Aged Humans

Myeloid-Derived Suppressor Cells in Aged Humans

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells whose
immunosuppressive activities contribute to cancer and other diseases. MDSCs
appear to increase with age, and this presumably contributes to immunosuppression
and the increased incidence of certain diseases. Why MDSCs increase with
age is not entirely clear. Herein we present evidence that MDSC expansion is due
in part to age-related changes in hematopoiesis, including the acquisition of
mutations that favor myelopoiesis, which are compounded by changes in the
aging microenvironment that favor the production of MDSCs.