Daniel A. Portnoy

[3] To further his appreciation of host cells, he did his postdoctoral fellowship in the Zanvil Cohn Laboratory of Cellular Physiology and Immunology at the Rockefeller University in New York, working with Jay Unkeless and Jeff Ravetch.

[5] In collaboration with Dr. Philip Youngman, he showed that expression of the L. monocytogenes hemolysin by Bacillus subtilis led to its growth inside of host cells.

In 1997, Dr Portnoy moved to UC Berkeley where his lab continues to examine fundamental aspects of L. monocytogenes biology, and has expanded to focus on both innate and acquired immunity in the context of Listeria infection.

Dr. Portnoy and collaborators have shown that immune cells recognize cyclic di-AMP, a novel and essential bacterial signaling molecule, secreted by L. monocytogenes through multidrug resistance efflux transporters.

[11][12] Dr. Portnoy and Dr. Russell Vance identified that STING was the host receptor of cyclic-di-nucleotides (CDNs) that leads to the production of type I interferon and other co-regulated genes.

Cartoon and electron micrographs from Dr. Portnoy's seminal observation that L. monocytogenes utilizes host actin to spread cell-to-cell. J Cell Biol 2002 Aug 158(3) 409–14, Figure 1.