Come work on a parasite that has outsmarted every host it has met

Postdoctoral fellows

We always consider exceptional candidates who want to find out how Toxoplasma survives inside human cells, although no position is advertised at the moment. Current work is funded by two NIH R01 grants: one on how human cells restrict parasite growth after interferon-γ stimulation (2023 to 2028), and one, with Baoyu Chen, on how infected immune cells carry the parasite through the body (2022 to 2027).

What you would work on

• How interferon-γ-stimulated human cells attack the vacuole the parasite lives in, and the parasite proteins that resist them, including GRA45, the GRA70 complex and GRA66.
• How Toxoplasma takes lipids from its host while sealed inside that vacuole, through secreted proteins such as TgSEC14-LTP1 and GRA38.
• How the parasite makes infected dendritic cells and macrophages migrate, and how that spreads the infection.
• How human immune cells first recognise that a cell is infected.

Most projects start from genome-wide CRISPR screens in the parasite, run in vivo and in naive or interferon-γ-stimulated mouse, rat and human cells. Hits are then taken apart with cell biology, biochemistry, lipidomics and structural modelling. The research page describes each line of work.

Recent first-author papers by postdocs in the lab

• Cruz-Miron R et al. TgSEC14-LTP1 is a vacuole-secreted SEC14/CRAL-TRIO-like protein required for host DAG flux and PC homeostasis in T. gondii. Cell Reports 2026.
• Bitew MA et al. A genome-wide CRISPR screen identifies GRA38 as a key regulator of lipid homeostasis during Toxoplasma gondii adaptation to lipid-rich conditions. Nature Communications 2025.
• de Moraes de Siqueira C et al. Toxoplasma gondii GRA66 prevents premature egress driven by the host phospholipase RARRES3, independently of RNF213. bioRxiv 2026.

Where our postdocs went

Eight former postdocs now hold faculty positions: Kirk Jensen (UC Merced), Daniel Gold (St. Edward’s University), Musa Hassan (The Roslin Institute, University of Edinburgh), Cynthia Cordeiro (Faculdade de Medicina de Campos), Eleni Konstantinou (Weill Cornell Medicine), Lamba Omar Sangaré (Texas A&M University), Debanjan Mukhopadhyay (Presidency University, Kolkata) and Yifan Wang (University of Michigan Medical School). Others went on to roles at Scripps Research, Intellia Therapeutics, Mass General Brigham Innovation, Agilent Technologies and mAbTree Biologics. The full list is on the people page.

How to apply

Email Jeroen Saeij with your CV, a cover letter that says which of the questions above interests you and why, and the names and email addresses of three references.

Postdocs in the lab are encouraged to apply for their own fellowships. Shruthi Krishnamurthy and Debanjan Mukhopadhyay held American Heart Association fellowships, and Yifan Wang’s NIH K99 award helped him start his own lab at the University of Michigan. If you plan to apply for a fellowship, say so in your email.

Graduate students

The Saeij lab trains students from the Microbiology, Immunology and Integrative Pathobiology graduate groups at UC Davis. Admission is through the graduate group; once you are at UC Davis, contact Jeroen to arrange a rotation. Rotating and joining students are strongly encouraged to apply for fellowships. NSF Graduate Research Fellowship applications are due in October and can only be submitted in the first year, so plan early; Jeroen is happy to help with the application.

Undergraduate students

We train motivated undergraduates who can commit to at least two years in the lab.

Visiting students

Students enrolled at another university, in the United States or abroad, are welcome to do research in the lab if they can stay for at least nine months and can show that they are able to support their stay in Davis.

Life in Davis

UC Davis has the top-ranked veterinary school in the country. Davis itself is a friendly university town close to Sacramento, San Francisco, the Napa and Sonoma wine country and the Sierra Nevada. UC Davis offers excellent benefits and professional development for postdocs.