Mouse IgG1 Isotype Control [CF405M]

Therapeutic monoclonal antibodies (mAbs) have high efficacy in treating TNF alpha-related immunological diseases. Other than neutralizing TNF alpha, these IgG1 antibodies exert Fc receptor-mediated effector functions such as the complement-dependent cytotoxicity (CDC) and antibody-dependent cell cytotoxicity (ADCC). The crystallizable fragment (Fc) of these IgG1 contains a single glycosylation site at Asn 297/300 that is essential for the CDC and ADCC. Glycosylated antibodies lacking core fucosylation showed an improved ADCC. However, no structural data are available concerning the ligand-binding interaction of these mAbs used in TNF alpha-related diseases and the role of the fucosylation. We therefore used comparative modeling for generating complete 3D mAb models that include the antigen-binding fragment (Fab) portions of infliximab, complexed with TNFa (4G3Y. pdb), the Fc region of the human IGHG1 fucosylated (3SGJ) and afucosylated (3SGK) complexed with the Fc receptor subtype Fc gamma RIIIA, and the Fc region of a murine immunoglobulin (1IGT). After few thousand steps of energy minimization on the resulting 3D mAb models, minimized final models were used to quantify interactions occurring between FccRIIIA and the fucosylated/afucosylated Fc fragments. While fucosylation does not affect Fab-TNF alpha interactions, we found that in the absence of fucosylation the Fc-mAb domain and Fc gamma RIIIA are closer and new strong interactions are established between G129 of the receptor and S301 of the Chimera 2 Fc-mAb; new polar interactions are also established between the Chimera 2 Fc residues Y299, N300, and S301 and the Fc gamma RIIIA residues K128, G129, R130, and R155. These data help to explain the reduced ADCC observed in the fucosylated mAbs suggesting the specific AA residues involved in binding interactions.

Introduction: The pathophysiology and temporal dynamics of affected tissues in chronic rhinosinusitis (CRS) remain poorly understood. Here, we present a multiomics-based time-series assessment of nasal polyp biopsies from three patients with CRS, assessing natural variability over time and local response to systemic corticosteroid therapy. Methods: Polyp tissue biopsies were collected at three time points over two consecutive weeks. Patients were prescribed prednisone (30 mg daily) for 1 week between Collections 2 and 3. Polyp transcriptome, proteome, and microbiota were assessed via RNAseq, SWATH mass spectrometry, and 16S ribosomal RNA and ITS2 amplicon sequencing. Baseline interpatient variability, natural intrapatient variability over time, and local response to systemic corticosteroids, were investigated. Results: Overall, the highly abundant transcripts and proteins were associated with pathways involved in inflammation, FAS, cadherin, integrin, Wnt, apoptosis, and cytoskeletal signaling, as well as coagulation and B- and T-cell activation. Transcripts and proteins that naturally varied over time included those involved with inflammation- and epithelial-mesenchymal transition-related pathways, and a number of common candidate target biomarkers of CRS. Ten transcripts responded significantly to corticosteroid therapy, including downregulation of TNF, CCL20, and GSDMA, and upregulation of OVGP1, and PCDHGB1. Members of the bacterial genus Streptococcus positively correlated with immunoglobulin proteins IGKC and IGHG1. Conclusions: Understanding natural dynamics of CRS-associated tissues is essential to provide baseline context for all studies on putative biomarkers, mechanisms, and subtypes of CRS. These data further our understanding of the natural dynamics within nasal polypoid tissue, as well as local changes in response to systemic corticosteroid therapy.