Faber, ErikaTshilwane, Selaelo IvyVan Kleef, MirindaPretorius, Alri2022-10-122022-12Faber, E., Tshilwane, S.I., Van Kleef, M. & Pretorius, A. 2022, 'The impact of Escherichia coli contamination products present in recombinant African horse sickness virus serotype 4 proteins on the innate and humoral immune responses', Molecular Immunology, vol. 152, pp. 1-13, doi : 10.1016/j.molimm.2022.09.013.0161-5890 (print)1872-9142 (online)10.1016/j.molimm.2022.09.013https://repository.up.ac.za/handle/2263/87645Transcriptome analysis was used to characterise the in vitro primary and secondary immune responses induced in horse peripheral blood mononuclear cells (PBMC) stimulated for 24 h with the individual recombinant proteins of a virulent AHSV serotype 4 (AHSV4) field isolate (rAHSV4 proteins) that were previously expressed in Escherichia coli (E. coli). The results showed that the E. coli contamination products greatly affected the innate and humoral immune response transcripts. Hence, the impact of E. coli contamination products present in the individual rAHSV4 proteins on the translational immune response was determined. The combined amplification effects of synergistic pattern recognition receptors (PRRs), TNF-α and IL-1β signalling induced potent pro-inflammatory responses that were too overwhelming for the anti-inflammatory cytokines and regulators to control. In addition to inducing robust B cell and antibody-mediated responses, lipopolysaccharide (LPS) activation of the innate-like B cells and subsequent polyreactive (natural) antibody responses could potentially contribute to endotoxin tolerance.en© 2022 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Molecular Immunology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Molecular Immunology, vol. 152, pp. 1-13, 2022. doi : 10.1016/j.molimm.2022.09.013.HyperinflammationPolyreactive (natural) antibodiesInnate-like B cellsEndotoxin toleranceLipopolysaccharideEscherichia coliRecombinant proteinsTranscriptome analysisPeripheral blood mononuclear cells (PBMC)African horse sickness virus (AHSV)Postprint Article