| CDI | Clostridioides difficile infection |
| IECs | Intestinal epithelial cells |
| BclA | Bacillus collagen-like protein of anthracis |
| NTD | N-terminal domain |
| CTD | C-terminal domain |
| BclA2CTD | C-terminal domain of BclA2 |
| BclA3CTD | C-terminal domain of BclA3 |
| APCs | Antigen-presenting cells |
| IEDB | Immune epitope database |
| MHC | Major Histocompatibility complex |
| SDS-PAGE | Sodium Dodecyl Sulphate-polyacrylamide gel electrophoresis |
| Sp | Spores of B. subtilis |
| PBS | Phosphate buffered saline |
| ANOVA | Analysis of variance |
| ELISA | Enzyme-linked immunosorbent assay |
| IgG | Immunoglobulin G |
| IgA | Immunoglobulin A |
| MALT | Mucosal-associated lymphoid tissue |
| I.P | Intraperitoneal |
| Wt | Wild type |
| PI | Pre-Immune |
| d13 | Day 13 |
| d27 | Day 27 |
| d42 | Day 42 |
| OD | Optical density |
| CFU | Colony forming unit |
| TTFC | C fragment of the tetanus toxin |
| TLR | Toll-Like Receptors |
| NLR | Nod-Like Receptors |
| FACS | Fluorescence-activated cell sorting |
| DMEM | Dulbecco’s Modified Eagle Medium |