3253 Identification of Immune Cell Profiles and Molecular Pathways in Inflammatory Bowel Disease Driving Non-Response to Biologic Therapy
Authors: Penrose Harrison Michael , Nakhoul Hani , Ungerleider Nathan , Flemington Erik , Savkovic Suzana 
Published: March 2019

OBJECTIVES/SPECIFIC AIMS: Inflammatory Bowel Disease (IBD) is a chronic, life-long condition characterized by inflammation of the intestine that greatly affects an individual’s quality of life. While biologic therapy directed against TNFα (anti-TNFα, Infliximab) and α4β7 integrin (anti-α4β7; Vedolizumab) is used to treat IBD, a substantial number of patients remain non-responsive. Using a comprehensive bioinformatics approach, the aim of this study was to characterize immune cell profiles and altered molecular pathways in IBD patient non-responders to anti-TNFα and anti-α4β7 therapy to determine potential mechanisms and/or indicators of treatment non-response. METHODS/STUDY POPULATION: Publicly available whole transcriptomes from 65 healthy control and IBD endoscopic biopsies were assessed (NCBI GEO GSE73661). Specifically, transcript profiles from responders or non-responders to anti-TNFα and anti-α4β7 therapy were utilized. Differentially expressed transcript profiles were obtained by comparing responders or non-responders prior to receiving therapy versus healthy controls using NCBI’s GEO2R after adjustment with Benjamini and Hochberg testing (p<0.05). Immune profiling of DEgs were analyzed by the core LM22 immune signature for subsets of B-, T-, dendritic-, mast-cells, macrophages, and neutrophils (CIBERSORT, cibersort.stanford.edu) (p<0.05). Networks, functional analysis, and interpretation of transcriptomic data were performed using Ingenuity Pathway Analysis (IPA) (Qiagen) (p<0.05). RESULTS/ANTICIPATED RESULTS: Initially, we determined colonic immune profiles in responders and non-responders to anti-TNFα and anti-α4β7 therapy. Compared to responders, in both anti-TNFα and anti-α4β7 non-responders we found elevated neutrophil levels (p<0.05). Specific to anti-TNFα treatment, non-responders demonstrated substantially reduced Treg cells (p<0.05); whereas, exclusive to anti-α4β7 treatment, non-responders showed elevated dendritic cells, activated CD4 T cells, and reduced M2 macrophages (p<0.05). Next we profiled differentially expressed transcripts to determine molecular pathways associated with therapy non-response. In both anti-TNFα and anti-α4β7 non-responders, we observed alterations in pathways specific to cellular growth and metabolism. Among cell growth pathways we found activated growth hormone, Wnt, ErB, and IGF-1 signaling; whereas, among metabolic regulation we found altered triglyceride, tryptophan, and leptin signaling. Moreover, unique to anti-TNFα non-responders, we found activated sphinogosine-1-phosphate and paxillin pathways. While non-response to anti-α4β7 indicated activation of SAPK/JNK and IL-9 signaling. DISCUSSION/SIGNIFICANCE OF IMPACT: Together these data define specific immune profiles and molecular pathways observed in non-responders to anti-TNFα and anti-α4β7 therapy. Our analysis identified substantial alterations in pathways specific to cellular growth and metabolism, identifying a link between non-response to biologic therapy and specific cell functions. These data suggest particular alterations in immune profiles and molecular pathways could play a role in non-response to biologic therapy, highlighting a future direction for personalized treatment regimens that could lead to more targeted use of existing therapies and more favorable patient health outcomes.