Biology subjects

Kerns, S. J.

Publications and source records attributed to Kerns, S. J..

3 recordsLinked to original sources

bioRxiv2022

Phenotypic Characterization of Liver Sinusoidal Endothelial Cells on the Human Liver-Chip for Potential in vitro Therapeutic Antibody Pharmacology Applications

Liver plays a vital role in the human immune system, in the internalization and catabolic clearance of therapeutic antibodies and antibody-bound immune complexes via Fc-receptor (FcR) binding on the hepatic reticuloendothelial system cells. This Fc portion of the antibody binding to FcR in the liver initiates the clearance of these antibodies or immune complexes, which is vital in the context of half-life, dosing interval, efficacy, and safety of therapeutic antibodies. The liver sinusoidal endothelial cells (LSECs) express scavenging receptors that recognize, bind, and internalize an enormous diversity of extracellular ligands. The Fc gamma receptor Fc{gamma}RIIB or CD32B on LSECs is responsible for the clearance of a large majority of IgG-bound immune complexes in the liver. Investigating the pharmacological effects of antibody clearance via human liver in vitro has been challenging due to the lack of reliable long-term LSEC culture protocols. Human LSECs downregulate the expression of CD32B rapidly in vitro in traditional 2D LSEC mono- and co-cultures. We describe a Liver-Chip model with a co-culture of primary human LSECs and hepatocytes to recreate the liver microenvironment and extend the viability and function of LSECs, including CD32B expression levels, for a duration that is relevant for assessing the pharmacokinetics (PK) of therapeutic antibodies. Our results show that the expression of CD32B can differ based on experimental variables such as the source of primary cells (donor), passage number or source of detection antibodies used to visualize CD32B and shear stress. The CD32B expression was maintained for 14 days on the Liver-Chip in a donor-dependent but passage number independent manner. The Scanning Electron Microscopy (SEM) imaging showed the presence of fenestrae structures - one of the hallmarks of LSEC function. Key LSEC markers, including CD32B expression, were validated through flow cytometry.

bioengineering↗

bioRxiv2021

Human immunocompetent Organs-on-Chips platforms allow safety profiling of tumor-targeted T-cell bispecific antibodies

AbstractTraditional drug safety assessment often fails to predict complications in humans, especially when the drug targets the immune system. Here, we show the unprecedented capability of two Organs-on-Chips to evaluate the safety profile of T-cell bispecific antibodies (TCBs) targeting tumor antigens. Although promising for cancer immunotherapy, TCBs are associated with an on-target, off-tumor risk due to low levels of expression of tumor antigens in healthy tissues. We leveraged in vivo target expression and toxicity data of TCBs targeting folate receptor 1 (FOLR1) or carcinoembryonic antigen (CEA) to design and validate human immunocompetent Organs-on-Chips safety platforms. We discovered that the Lung-Chip and Intestine-Chip could reproduce and predict target-dependent TCB safety liabilities, based on sensitivity to key determinants thereof, such as target expression and antibody affinity. These novel tools broaden the research options available for mechanistic understandings of engineered therapeutic antibodies and assessing safety in tissues susceptible to adverse events.

cancer biology↗

bioRxiv2018

A synthetic bacterial information transfer system functions in the mammalian gut

The gut microbiome is intricately involved with establishing and maintaining the health of the host. Engineering of gut microbes aims to add new functions and expand the scope of control over the gut microbiome. To create systems that can perform increasingly complex tasks in the gut with multiple engineered strains it is necessary to program communication among these bacteria in the gut. Towards this goal, we engineered an information transfer system for inter-cellular communication, using native gut Escherichia coli and attenuated Salmonella enterica serovar Typhimurium. Specifically, we have taken two genetic circuits-one for signaling from the quorum sensing system and the other for memory from the bacteriophage genetic switch-and integrated them into a robust system that can report on successful communication in the mammalian gut. Our system provides a basis for the construction of a programmable gut consortia as well as a basis for further understanding of bacterial interactions in an otherwise hard-to-study environment.

synthetic biology↗