Research Areas

Research Interests: Bacteria and cancer; host-pathogen interactions; immune evasion.

Our lab is interested in the broad area of bacterial-host interactions. The manifestation and progression of infectious diseases are determined by the combined effects of bacterial factors and host reactions. Understanding these interactions is critical for combating infectious diseases. Furthermore, some of the bacterial – host interactions may cause alterations in host physiological or cellular processes that contribute to other types of diseases including cancer. 

We are interested in Streptococcus gallolyticus subsp. gallolyticus (Sgg), a gut pathobiont.

Sgg, previously known as S. bovis biotype I, causes life-threatening infections such as bacteremia and infective endocarditis. It is also known to strongly correlate with CRC. Patients with Sgg infections have a 7-fold higher risk of developing colorectal adenoma/adenocarcinoma. Using a combination of in vitro cell cultures and mouse models, we demonstrated that Sgg actively promotes colon tumor growth. Sgg also possess the ability to disrupt the colonic epithelial barrier integrity and translocate across the epithelium. Thus, the gut occupies a central spot in the pathogenicity of Sgg. It provides a niche for Sgg to colonize the host and to spread to the circulation to cause infections. Residence of Sgg in the colon also influences gut homeostasis, thereby promoting the development of the colorectal cancer.

Our current research focus is to elucidate the specific Sgg factors that mediate gut colonization, dissemination, and promotion of tumor growth, and to delineate the host pathways targeted by these Sgg factors. In the long term, we hope to apply the knowledge to develop strategies to mitigate Sgg-induced pathologies.