Jesse Garcia Castillo, PhD

Congrats to the new class of Gilliam Fellows!! So awesome to see familiar faces at UC Berkeley and UCSF! It’s a fantastic community and hope you enjoy every minute of it!

Vitamin B2 metabolism promotes FSP1 stability to prevent ferroptosis https://www.biorxiv.org/content/10.1101/2025.08.05.668752v1

Join me in Boston October 6th for a 1-day conference on #mappingbiology to transform #cancertherapeutics. Register by September 25th to benefit from the complimentary (free) admission! Topics, speakers, and talk opportunities here: abcam.me/mappingbiolo...
@abcamofficial.bsky.social

Sometimes, knocking out a gene isn't a good way to figure out the function of that gene ...

In our new @jcellsci.bsky.social paper, we report potent transcriptional adaptation by cytotoxic T lymphocytes (CTLs) in response to CRISPR/Cas9-mediated deletion of the important polarity protein CDC42 🧵⬇️

Design of soluble Notch agonists that drive T cell development and boost immunity Mout et al. report the development of soluble Notch agonists that can be used for T cell development in suspension cultures and 3D bioreactors and for enhancing immunity in vivo.

Now online! Design of soluble Notch agonists that drive T cell development and boost immunity

The first FASEB Ferroptosis conference! ✔️ Thank you to my co-organizer Scott Dixon, our sponsors, and the whole #Ferroptosis community for showing up and making this such a wonderful meeting! 🤩 ❤️

We developed MouseMapper AI, a deep learning ensemble for the analysis of whole-body systems, including the nervous and immune systems, to map disease/drug perturbations tissue by tissue, organ by organ, at the cellular level in 3D.
biorxiv.org/content/10.1...

The 2025 Freeman Hrabowski Scholars | HHMI Freeman Hrabowski Scholars are outstanding early career faculty who have the potential to become leaders in their research fields.

Congrats to JCC alum Dr. Whitney Henry on being named an @hhmi.org Freeman Hrabowski Scholar!

Dr. Henry and her lab @mitkochinstitute.bsky.social study ferroptosis, an iron-dependent mechanism of cell death.

www.hhmi.org/programs/fre... 1/

The count down has begun! 1-week until the 1st FASEB Ferroptosis conference! Looking forward to seeing everyone at the meeting. Get excited!! 🤩
events.faseb.org/event/11797f...

Inflammaging in aged tissues drives remodeling of the CD8+ T cell compartment https://www.biorxiv.org/content/10.1101/2025.07.11.664388v1

Mitochondrial respiration is necessary for CD8+ T cell proliferation and cell fate @natimmunol.nature.com
www.nature.com/articles/s41...

My third paper from grad school is out on Biorxiv! This was a fun collaboration with @olzmannlab.bsky.social where we show that Ferroptosis Suppressor Protein-1 is a better target than GPX4 because it disrupts Treg function while leaving effector T cell function intact.

I'm excited about a new @biorxivpreprint.bsky.social story that just went live! This one takes a #computational #immunology approach to understanding #tissueresident lymphocytes. The story highlights the extra value mathematical modelling can bring to biology. 🧵1/10

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

Stimulating immune cells in vitro is a common experimental lab model. We profiled 150K blood immune cells treated with 11 different stimuli to compare the effects. The data are freely available for researchers. See the preprint for our findings and to access the data 🧪 doi.org/10.1101/2025...

In the minority here, but I think it would be refreshing and I'd appreciate reading a piece like "On the value of reductionist science".

While *incredibly* valuable, not everything *needs* -omics and the like, let alone when only done because it _can_ be done, with an illusion of mechanism.

Will be attending the FASEB Immune Signaling conference starting today! First conference as a postdoc and looking forward to meeting everyone.

One thing that really bothers me with the new "virtual cell" terminology is that it is currently largely focused on a very narrow definition of models that can predict effects of trans perturbations (gene dosage, drugs etc) on gene expression. 1/

PD-1 receptor deficiency enhances CD30+ Treg cell function in melanoma Nature Immunology - Here the authors show that PD-1 controls coinhibitory receptor expression by Treg cells. The absence of PD-1 expression could induce CD30 expression, thereby enhancing Treg...

Amarnath and colleagues find that PD-1 controls coinhibitory receptor expression in Tregs. Read it here: rdcu.be/etDtN
www.nature.com/articles/s41...

Cathepsin L-dependent positive selection shapes clonal composition and functional fitness of CD4+ T cells Nature Immunology - Klein and colleagues show that the lysosomal cysteine protease cathepsin L shapes the diversity and optimizes the fitness of clones that enter the CD4+ T cell repertoire.

Klein and colleagues find that cathepsin L shapes CD4+ T cell selection by promoting full repertoire diversity and fine-tuning CD4+ T cell functionality. Read it here: rdcu.be/etDy2
www.nature.com/articles/s41...

Some familiar faces!! Congrats to @scienceyael.bsky.social, @lewsiferase.bsky.social, Aurora, and the rest!!

Love seeing a familiar author!! Congrats Andrea, Sarah, and Dan!!

Thank you!!! 😊

This is why I unsubscribed to NYT. Although I do miss the daily games on there. 🤷🏽‍♂️

Picture of the No Kings protest today Shot a lot of drone footage before being told to ground by State Patrol as their patrol helicopter had arrived. Peaceful the entire time I was...

Despite the political assassination spree overnight in Minnesota with the suspect running free, there was still a giant turnout in the Twin Cities.

Reddit.com/r/minnesota/comments/1lbhemc/picture_of_the_no_kings_protest_today/

We Are Entering Uncharted Territory Here, Folks A U.S. senator was thrown down and handcuffed as the DHS secretary announced the "liberation" of California.

U.S. senator thrown down, handcuffed as DHS secretary announces "liberation" of California.

ICE will be ramping up its activity in Philadelphia, Seattle, NYC, Chicago, and Northern Virginia.

Stay the fuck out of Philly!!

S.F. immigration court shut down by anti-ICE protesters ICE agents arrested at least two people outside San Francisco court on Tuesday, bringing crowds out to the courtroom and shutting it down.

UPDATE: After video circulated showing ICE agents in San Francisco arresting people outside court, protesters shut the immigration court down for the day.

About 200 people amassed outside 100 Montgomery St. The afternoon immigration docket was cancelled.

missionlocal.org/2025/06/vide...

#jaylies #truthmatters Oh my god. Jay now says it's paradise in the US for young researchers--no other place is more generous than the US on biomedical research funding. You've cut training grants, terminated thousands of grants for new researchers.

BREAKING: Federal agents in plain clothes and unmarked cars tried to snatch 1st graders from LA elementary schools—told staff they had “parental consent.”

They lied. When pressed, they HID THEIR IDS. DHS admits they sent them. This wasn’t a welfare check. It was a test run for a police state.

Our Founding Fathers would have had a word for calling up a battalion of Marines for regular domestic law enforcement: tyranny.