Jesse Garcia Castillo, PhD
@jgcastillo.bsky.social
CRI Irvington Postdoctoral Fellow/Jeroen Roose’s lab at UCSF. HHMI Gilliam Fellow'21. Berkeley MCB PhD alum/Michel DuPage’s Lab. Cal State LA alum. 🏳️🌈🇲🇽 (He/His/Him). Interested in all things immunology, but T cells are my favorite!
Pinned
Selective disruption of lipid peroxide homeostasis in intratumoral regulatory T cells by targeting FSP1 enhances cancer immunity https://www.biorxiv.org/content/10.1101/2025.07.06.663397v1
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.
Reposted by Jesse Garcia Castillo, PhD
Santiago-Carvalho et al. identified the extracellular ATP sensor P2RX7 as a poor prognostic factor in NSCLC that was highly enriched in Tregs. In mouse models, Treg-specific KO of P2RX7 reduced lung tumor burden, without altering Treg numbers. bit.ly/4quiPdW @mayocliniccancer.bsky.social
February 12, 2026 at 12:30 PM
Santiago-Carvalho et al. identified the extracellular ATP sensor P2RX7 as a poor prognostic factor in NSCLC that was highly enriched in Tregs. In mouse models, Treg-specific KO of P2RX7 reduced lung tumor burden, without altering Treg numbers. bit.ly/4quiPdW @mayocliniccancer.bsky.social
Reposted by Jesse Garcia Castillo, PhD
Proteostasis sustains T cell differentiation potential and tumor-infiltrating lymphocyte function https://www.biorxiv.org/content/10.64898/2026.02.08.704716v1
February 10, 2026 at 11:17 PM
Proteostasis sustains T cell differentiation potential and tumor-infiltrating lymphocyte function https://www.biorxiv.org/content/10.64898/2026.02.08.704716v1
Reposted by Jesse Garcia Castillo, PhD
February 9, 2026 at 1:36 AM
Reposted by Jesse Garcia Castillo, PhD
A little late on here but happy to share my 3rd first author paper from grad school finally out in Science Advances!! In collaboration with James Olzmann's group, we find that Tregs utilize FSP1/Aifm2 for preventing lipid peroxide accumulation and preserve their suppressive function in tumor models.
Thrilled to have contributed to this work led by @jgcastillo.bsky.social during his PhD at UC Berkeley w/ Michel DuPage. Targeting FSP1 in T cells boosts anti-tumor immunity by relieving Treg suppression, revealing a new immunomodulatory therapeutic axis. www.science.org/doi/10.1126/...
Selective disruption of lipid peroxide homeostasis in intratumoral regulatory T cells by targeting FSP1 enhances cancer immunity
Deletion of Aifm2 disrupts Treg cell immunosuppression within tumors without inciting autoimmune pathology in mice.
www.science.org
February 6, 2026 at 12:58 AM
A little late on here but happy to share my 3rd first author paper from grad school finally out in Science Advances!! In collaboration with James Olzmann's group, we find that Tregs utilize FSP1/Aifm2 for preventing lipid peroxide accumulation and preserve their suppressive function in tumor models.
Reposted by Jesse Garcia Castillo, PhD
@biorxivpreprint.bsky.social The CD8 immgenT framework as a universal reference of mouse CD8 Tαβ cell differentiation states
www.biorxiv.org/content/10.6...
www.biorxiv.org/content/10.6...
February 5, 2026 at 1:38 AM
@biorxivpreprint.bsky.social The CD8 immgenT framework as a universal reference of mouse CD8 Tαβ cell differentiation states
www.biorxiv.org/content/10.6...
www.biorxiv.org/content/10.6...
Reposted by Jesse Garcia Castillo, PhD
Atlas-guided discovery of transcription factors for T cell programming @nature.com @salkinstitute.bsky.social @tcellogic.bsky.social @ucsdmedschool.bsky.social
www.nature.com/articles/s41...
www.nature.com/articles/s41...
February 4, 2026 at 7:44 PM
Atlas-guided discovery of transcription factors for T cell programming @nature.com @salkinstitute.bsky.social @tcellogic.bsky.social @ucsdmedschool.bsky.social
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Jesse Garcia Castillo, PhD
Selective Immune Silencing by Targeted TGF-β Agonists https://www.biorxiv.org/content/10.64898/2026.01.19.700410v1
January 20, 2026 at 5:16 PM
Selective Immune Silencing by Targeted TGF-β Agonists https://www.biorxiv.org/content/10.64898/2026.01.19.700410v1
Reposted by Jesse Garcia Castillo, PhD
A ‘simple’ experiment but an amazing gem of a reference!
Just stimulate blood, observe and describe…
#ImmunoSky
Just stimulate blood, observe and describe…
#ImmunoSky
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...
July 6, 2025 at 1:18 PM
A ‘simple’ experiment but an amazing gem of a reference!
Just stimulate blood, observe and describe…
#ImmunoSky
Just stimulate blood, observe and describe…
#ImmunoSky
Reposted by Jesse Garcia Castillo, PhD
The TCF1-PTMA axis maintains mitochondrial homeostasis to sustain CD8 T cell function and preserve immune checkpoint blockade efficacy @sciimmunology.bsky.social
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
January 17, 2026 at 4:59 AM
The TCF1-PTMA axis maintains mitochondrial homeostasis to sustain CD8 T cell function and preserve immune checkpoint blockade efficacy @sciimmunology.bsky.social
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
Reposted by Jesse Garcia Castillo, PhD
Threw an unfinished TCR analysis library and bunch of notebooks with patient-specific functionality into Claude Code and...it generalized the new features perfectly into a very reasonably structured tool. Had a few nitpicks, now they're fixed.
Uh, hard to go back.
Uh, hard to go back.
January 15, 2026 at 5:24 PM
Threw an unfinished TCR analysis library and bunch of notebooks with patient-specific functionality into Claude Code and...it generalized the new features perfectly into a very reasonably structured tool. Had a few nitpicks, now they're fixed.
Uh, hard to go back.
Uh, hard to go back.
Reposted by Jesse Garcia Castillo, PhD
In vivo detection of immune responses via cytokine activity labeling @cellcellpress.bsky.social @harvardmed.bsky.social
www.cell.com/cell/fulltex...
www.cell.com/cell/fulltex...
January 7, 2026 at 10:34 PM
In vivo detection of immune responses via cytokine activity labeling @cellcellpress.bsky.social @harvardmed.bsky.social
www.cell.com/cell/fulltex...
www.cell.com/cell/fulltex...
Reposted by Jesse Garcia Castillo, PhD
Antigen reactivity defines tissue-resident memory and exhausted T cells in tumors @thedohertyinst.bsky.social @unimelb.bsky.social @natimmunol.nature.com www.nature.com/articles/s41...
December 29, 2025 at 4:07 PM
Antigen reactivity defines tissue-resident memory and exhausted T cells in tumors @thedohertyinst.bsky.social @unimelb.bsky.social @natimmunol.nature.com www.nature.com/articles/s41...
Reposted by Jesse Garcia Castillo, PhD
Tissue-resident exhausted and memory CD8+ T cells have distinct ontogeny, function and role in disease
www.nature.com/articles/s41... @natimmunol.nature.com @ejohnwherry.bsky.social @upenn.edu
www.nature.com/articles/s41... @natimmunol.nature.com @ejohnwherry.bsky.social @upenn.edu
December 29, 2025 at 3:48 PM
Tissue-resident exhausted and memory CD8+ T cells have distinct ontogeny, function and role in disease
www.nature.com/articles/s41... @natimmunol.nature.com @ejohnwherry.bsky.social @upenn.edu
www.nature.com/articles/s41... @natimmunol.nature.com @ejohnwherry.bsky.social @upenn.edu
Reposted by Jesse Garcia Castillo, PhD
Impact of vector copy number on critical quality attributes of retrovirally-engineered T cells
@moltherapy.bsky.social
www.cell.com/molecular-th...
@moltherapy.bsky.social
www.cell.com/molecular-th...
Impact of vector copy number on critical quality attributes of retrovirally-engineered T cells
Current regulatory guidance on engineered T-cell VCN limits focuses on the risk of
insertional oncogenesis. However, impact of these limits on other cell product characteristics
is unclear. Norberg an...
www.cell.com
December 26, 2025 at 2:02 AM
Impact of vector copy number on critical quality attributes of retrovirally-engineered T cells
@moltherapy.bsky.social
www.cell.com/molecular-th...
@moltherapy.bsky.social
www.cell.com/molecular-th...
Reposted by Jesse Garcia Castillo, PhD
New findings from Zhang, Honjo, Chamoto et al. @ccii-kyoto.bsky.social indicate that a subset of cancer cells expressing CTAs is sufficient to evoke overall antitumor immunity by broadening T cell responses to other neoantigens. rupress.org/jem/article/...
#TumorImmunology
#TumorImmunology
December 19, 2025 at 4:15 PM
New findings from Zhang, Honjo, Chamoto et al. @ccii-kyoto.bsky.social indicate that a subset of cancer cells expressing CTAs is sufficient to evoke overall antitumor immunity by broadening T cell responses to other neoantigens. rupress.org/jem/article/...
#TumorImmunology
#TumorImmunology
Reposted by Jesse Garcia Castillo, PhD
Matsuura et al. showed that PGE2 in the TME induced tumor-infiltrating Treg (TI-Treg) signature genes through the EP2/EP4–cAMP–PKA signaling axis in both induced and naturally occurring Tregs, enhancing their suppressive potency. bit.ly/4s3milI
December 19, 2025 at 4:30 PM
Matsuura et al. showed that PGE2 in the TME induced tumor-infiltrating Treg (TI-Treg) signature genes through the EP2/EP4–cAMP–PKA signaling axis in both induced and naturally occurring Tregs, enhancing their suppressive potency. bit.ly/4s3milI
Reposted by Jesse Garcia Castillo, PhD
Online now: Opposing functions of distinct regulatory T cell subsets in colorectal cancer
Opposing functions of distinct regulatory T cell subsets in colorectal cancer
Huang et al. study the heterogeneity of regulatory T (Treg) cells in a genetic model of colorectal cancer (CRC) and find that interleukin (IL)-10− Treg cells promote tumor progression, whereas IL-10+ Treg cells restrain tumor growth by suppressing IL-17 production from CD4+ T cells. This functional dichotomy between Treg subsets is seen in human CRC and may be relevant in other barrier tissue cancers.
dlvr.it
December 15, 2025 at 8:55 PM
Online now: Opposing functions of distinct regulatory T cell subsets in colorectal cancer
Not only are these folks great scientists, but they give back to their communities. Miss working with them!
Portnoy Lab microbiologists brought hands-on science to a local elementary school by creating a Microbe Circuit—sparking curiosity and inspiring future scientists. 🧪🦠
mcb.berkeley.edu/news-and-eve...
mcb.berkeley.edu/news-and-eve...
December 15, 2025 at 4:49 PM
Not only are these folks great scientists, but they give back to their communities. Miss working with them!
Reposted by Jesse Garcia Castillo, PhD
“The only reason I don’t have this funding is because my last name is Rodriguez.”
MOSAIC checked many of the boxes of the administration — but that didn't matter. It was terminated, and left grantees scrambling
Next installment of American Science, Shattered:
www.statnews.com/2025/12/08/t...
MOSAIC checked many of the boxes of the administration — but that didn't matter. It was terminated, and left grantees scrambling
Next installment of American Science, Shattered:
www.statnews.com/2025/12/08/t...
NIH shut out hundreds of young scientists from funding to start their own labs
Special Report: The NIH has shut out hundreds of young scientists from funding to start their own labs.
www.statnews.com
December 8, 2025 at 2:51 PM
“The only reason I don’t have this funding is because my last name is Rodriguez.”
MOSAIC checked many of the boxes of the administration — but that didn't matter. It was terminated, and left grantees scrambling
Next installment of American Science, Shattered:
www.statnews.com/2025/12/08/t...
MOSAIC checked many of the boxes of the administration — but that didn't matter. It was terminated, and left grantees scrambling
Next installment of American Science, Shattered:
www.statnews.com/2025/12/08/t...
Reposted by Jesse Garcia Castillo, PhD
If you or your trainees are just getting started with image analysis of cells & are #CellProfiler -curious, here is a fairly thorough walk-through demo I did recently. Loading files, extracting metadata (fun with Regex!), identifying objects, measuring, filtering, QC, exporting:
youtu.be/fO5nJdhj_7I
youtu.be/fO5nJdhj_7I
Introduction to CellProfiler - by a biologist, for biologists!
YouTube video by CellMorphoJSero
youtu.be
December 4, 2025 at 12:37 PM
If you or your trainees are just getting started with image analysis of cells & are #CellProfiler -curious, here is a fairly thorough walk-through demo I did recently. Loading files, extracting metadata (fun with Regex!), identifying objects, measuring, filtering, QC, exporting:
youtu.be/fO5nJdhj_7I
youtu.be/fO5nJdhj_7I
Reposted by Jesse Garcia Castillo, PhD
Reposted by Jesse Garcia Castillo, PhD
Just 4 days until the start of I2K and its 33 totally free image analysis tutorials and events! Please share with your "home networks", especially early career researchers - the videos will be amazing and high-impact no matter how many people attend live, BUT (1/x)
November 13, 2025 at 2:32 PM
Just 4 days until the start of I2K and its 33 totally free image analysis tutorials and events! Please share with your "home networks", especially early career researchers - the videos will be amazing and high-impact no matter how many people attend live, BUT (1/x)
Reposted by Jesse Garcia Castillo, PhD
Not every mentor is for every person. I always tell grad students to listen to what folks in the lab say about a mentor, but it’s okay to also see it for yourself in a rotation. It’s about the match - finding the person who can meet your needs (which are unique!).
November 13, 2025 at 8:56 PM
Not every mentor is for every person. I always tell grad students to listen to what folks in the lab say about a mentor, but it’s okay to also see it for yourself in a rotation. It’s about the match - finding the person who can meet your needs (which are unique!).
Reposted by Jesse Garcia Castillo, PhD
this is devastating for so many reasons and honestly, shame on the UC. Was hoping to keep the high going after Mamdani's win only come to falling back to earth and register that this country does not want us to succeed. www.insidehighered.com/news/faculty...
UC to Stop Funding Systemwide Postdoc Program
Established in 1984 to encourage women and minority Ph.D.s to pursue academia, the program has attracted right-wing criticism for prioritizing diverse candidates.
www.insidehighered.com
November 5, 2025 at 8:29 PM
this is devastating for so many reasons and honestly, shame on the UC. Was hoping to keep the high going after Mamdani's win only come to falling back to earth and register that this country does not want us to succeed. www.insidehighered.com/news/faculty...