Whitehead Institute welcomes Zuri Sullivan as its newest Member

Zuri Sullivan, an immunologist who studies how the immune system communicates with the brain to shape behavior during infection, joins Whitehead Institute this January as a Member. In addition to this appointment, Sullivan will join the MIT Department of Biology faculty as an assistant professor of biology. 

“My research lives between fields and draws from immunology, neuroscience, microbiology, and physiology,” Sullivan says. “Whitehead is a place where people approach biology from many angles, and this environment will shape how my lab generates ideas.”

Prior to joining Whitehead Institute, Sullivan conducted postdoctoral research in Catherine Dulac’s lab at Harvard University. She earned her PhD in immunology in 2020 in Ruslan Medzhitov’s lab at Yale University.

“Zuri’s work bridges disciplines in a way that exemplifies Whitehead’s commitment to interdisciplinary foundational science, and we are thrilled to welcome her to our community,” Whitehead Institute President and Director Ruth Lehmann says.

Sullivan’s research centers on sickness behavior: a conserved set of behavioral and physiological changes that arise during infection, including fever, loss of appetite, altered sleep, and social withdrawal. These responses are triggered by inflammatory signals produced during infection or injury and are thought to play an important role in survival. 

“When animals get sick, their behavior changes in very consistent ways,” she says. “These responses are deeply conserved across species, which suggests they’re doing something important. But we still know surprisingly little about how immune signals are translated into changes in brain activity, and whether those changes help the host, the pathogen, or sometimes both.”

Sullivan’s interest in host defense, the set of biological strategies organisms use to survive infection, began early in her career. As an undergraduate at Harvard College, she studied microbial pathogenesis in the lab of Eric Rubin and later investigated human immune responses to HIV and tuberculosis as a Fulbright Scholar in Durban, South Africa.

During her PhD, Sullivan discovered a previously unrecognized role for intestinal immune cells in helping tissues adapt to changes in diet, not only by defending against pathogens but also by regulating nutrient uptake. This work shaped how she thinks about immunity: as a system operating across the whole organism rather than as a purely cellular process.

Her postdoctoral research expanded this systems-level perspective to the brain. Sullivan investigated how different inflammatory states influence social behavior in mice, focusing on the hypothalamus, a brain region that regulates many processes disrupted during sickness. She found that sickness behavior is a coordinated, brain-wide response to infection, one that cannot be fully understood by studying immune cells or neurons in isolation.

“We found that neurons in the hypothalamus express a wide array of immune receptors, which gives the immune system a very direct line of communication with circuits that control behavior,” she says.

But much of what scientists currently know about sickness behavior comes from sterile models that mimic infection by activating the immune system without introducing a live pathogen. Instead, Sullivan hopes to study sickness behavior in the context of real, ongoing infections, where pathogens and hosts interact dynamically. 

“Different pathogens elicit very different immune responses, and we’re finding they can also produce different behavioral outcomes,” she says. “That raises new questions about how specific infections shape brain activity, and whether those behaviors are beneficial or harmful in different contexts.”

As her lab gets underway, Sullivan plans to expand her work across different types of infections and animal models. 

“At its core, my work is about understanding how living systems respond to one of the most fundamental threats to survival,” she says. “Infection is something every organism has to deal with, and sickness behavior is one of the most visible ways that biology adapts to that challenge.”

Her move to Whitehead Institute will allow her to pursue this research while collaborating with colleagues studying complementary systems in unique ways. 

“I want everyone in my lab to be exposed to many ways of thinking about biology,” she says. “Creative science often comes from making connections across systems, and Whitehead is uniquely well suited for that.”