Perelman School of Medicine at the University of Pennsylvania

Kohli Lab

Division of Infectious Diseases, Department of Medicine
Department of Biochemistry & Biophysics

Photos taken by: name of photograhper

News and Annoucments

Our thanks for the NIH for supporting our high-risk, high-reward ideas via an NIH Director's New Innovator Award!

The Edward Mallinckrodt, Jr. Foundation names Rahul as the 54th Mallinckrodt Scholar

See our work on the role of deaminases in DNA demethylation in Nature Chemical Biology, July 2012

Our thanks to the Doris Duke Foundation for awarding Rahul the Clinical Scientist Development Award!

Congratulations to Chris Nabel for the best poster award at the BMB Retreat, June 2012.

Best wishes to Laura Wang as she heads to Columbia Teacher's College!

Check out our review on cytosine as the genomic "wild card" (Jan 2012) in ACS Chemical Biology!

See our Perpective on DNA demethylation in Science (Sept 2011)

Our thanks to the Rita Allen Foundation for naming Rahul as a Rita Allen Scholar, June 2011

Congratulations to Charlie Mo for selection to the Cell and Molecular Biology Training Grant!

A warm welcome to our second lab baby, Charak Kohli, born June 17, 2011!

Welcome to Charlie Mo and Chris Nabel who have joined lab for their PhD thesis work

Our thanks to TriLink for supporting our lab's research through their Research Rewards Grant

Congratulation to Kiran Gajula on welcoming his first child, Joel Gajula, on March 9, 2011!

Check out our award winning "Grand Challenges" essay in Nature Chemical Biology, December 2010!

About Our Lab

Our laboratory focuses on the enzymatic generation of genomic diversity. We utilize a broad array of approaches, including biochemical characterization of enzyme mechanisms, chemical synthesis of enzyme probes, and biological assays spanning immunology and virology to study this central tactic in the constant battle between our immune system and pathogens.

From the host immune perspective, the generation of genomic diversity is used as both a defensive and an offensive weapon. On the one hand, host mutator enzymes such as Activation-Induced Deaminase (AID) seed diversity in the adaptive immune system by introducing targeted mutations into the immunoglobulin locus that result in high affinity antibodies (somatic hypermutation) or altered isotypes (class switch recombination). Related deaminases of the innate immune system can directly attack retroviral threats by garbling the pathogen genome through mutation, as accomplished by the deaminase APOBEC3G, which restricts infection with HIV. Immune mutator enzymes, however, also pose a risk to the host, as overexpression or dysregulation have been associated with oncogenesis (AID) or drug resistance (A3G).

From the pathogen perspective, alteration in key antigenic determinants at a rate that outpaces immune responses is a potent means for evasion. Further, rapid mutation may allow for the development of resistance to antimicrobials.

Our research program aims to understand mutator enzymes and pathways in the immune system and pathogens. We further aim to harness these diversity-generating systems for directed evolution of proteins. Additionally, we apply chemical biology to decipher and target these pathways, to impede the development of multidrug-resistance in pathogens or prevent the neoplastic transformations that can result from genomic mutation.

• Last updated: 11/09/2012