An atypical lipoteichoic acid from Clostridium perfringens elicits a broadly cross-reactive and protective immune response

Abstract

<jats:p><jats:italic>Clostridium perfringens</jats:italic> is a leading cause of food-poisoning and causes avian necrotic enteritis, posing a significant problem to both the poultry industry and human health. No effective vaccine against <jats:italic>C. perfringens</jats:italic> is currently available. Using an antiserum screen of mutants generated from a <jats:italic>C. perfringens</jats:italic> transposon-mutant library, here we identified an immunoreactive antigen that was lost in a putative glycosyltransferase mutant, suggesting that this antigen is likely a glycoconjugate. Following injection of formalin-fixed whole cells of <jats:italic>C. perfringens</jats:italic> HN13 (a laboratory strain) and JGS4143 (chicken isolate) intramuscularly into chickens, the HN13-derived antiserum was cross-reactive in immunoblots with all tested 32 field isolates, whereas only 5 of 32 isolates were recognized by JGS4143-derived antiserum. The immunoreactive antigens from both HN13 and JGS4143 were isolated, and structural analysis by MALDI-TOF-MS, GC-MS, and 2D NMR revealed that both were atypical lipoteichoic acids (LTAs) with poly-(β1→4)-ManNAc backbones substituted with phosphoethanolamine. However, although the ManNAc residues in JGS4143 LTA were phosphoethanolamine-modified, a few of these residues were instead modified with phosphoglycerol in the HN13 LTA. The JGS4143 LTA also had a terminal ribose and ManNAc instead of ManN in the core region, suggesting that these differences may contribute to the broadly cross-reactive response elicited by HN13. In a passive-protection chicken experiment, oral challenge with <jats:italic>C. perfringens</jats:italic> JGS4143 lead to 22% survival, whereas co-gavage with JGS4143 and α-HN13 antiserum resulted in 89% survival. This serum also induced bacterial killing in opsonophagocytosis assays, suggesting that HN13 LTA is an attractive target for future vaccine-development studies.</jats:p>

Ex Vivo Differential Responsiveness to Clostridium perfringens and Lactococcus lactis by Avian Small Intestine Macrophages and T Cells

“…TLR stimulation may be limited to either TLR2 or TLR4 and not TLR21. It is possible, in chickens, that highly virulent C. perfringens strains are least immunogenic in terms of innate sensing ( 52 ). In vivo experiments have also demonstrated that C. perfringens -induced TLR signaling in chickens is not sufficient to elicit cytokine expression such as IFN-γ due in part to an increase in IL-4 and IL-10 cytokine expression ( 14 , 22 ).…”

Improving Chicken Responses to Glycoconjugate Vaccination Against Campylobacter jejuni

“…For opsonophagocytosis assays, C. jejuni cells were incubated with fresh heparinized chicken blood and either naïve chicken serum or pooled chicken serum (from responder and non-responder birds) according to the method previously described by Goyette-Desjardins et al (2016) with modifications ( Wenzel et al, 2020 ). To prepare the bacterial cells, C. jejuni 81-176 was grown on BHI plates.…”

Lipoarabinomannan as a Point-of-Care Assay for Diagnosis of Tuberculosis: How Far Are We to Use It?

“…Little has been explored about the consequences of structural modifications in LAM before being released. Reports suggest that a glycosylation system or addition/breaking off of molecules is critical to delivering amphipathic molecules, like LTA from Clostridium perfringens or LTA from Staphylococcus aureus (Kho and Meredith, 2018;Wenzel et al, 2020). Mtb is capable of substituting α-(1→2)-Manp-linked residues with α-(1→4)-linked methylthio-D-xylose (MTX) residues, and modifying the branches of arabinofuranosides and mannose-capped versions, decreasing recognition of antibodies that are currently used in diagnostic methods based on immunoassays (Taghikhani and Moukhah, 2016;Angala et al, 2017;Choudhary et al, 2018).…”