Non-standard abbreviations: α-Galatosxylceramide (α-GalCer), acyl-CoA:cholesterol acyltransferases (ACATs), acute and critical illnesses (ACIs), antigen-presenting cells (APCs), antisense oligonucleotides (ASOs), apolipoprotein A-I (apoA-I), apolipoprotein B-48 (apoB-48), apolipoprotein B-100 (ApoB-100), 1-azido-3 1-deoxythymidine (AZT), chemokine (C-C motif) ligand 21 (CCL21), C C chemokine receptor type 7 (CCR7), CC-chemokine receptor 9 (CCR9), cholesterol (Ch), cholesterol esters (CEs), Crohn's disease (CD), computed tomography (CT), C-X-C motif chemokine 12 (CXCL12), cyclosporin A (CsA), cytosine phosphor-guanine oligodinucleotides (CpG), cytotoxic T lymphocyte (CTL), cytotoxic T lymphocyte antigen 4 (CTLA4), dendritic cells (DCs), diglycerides (DGs), diacylglycerol acyltransferases (DGATs), Notch ligand delta-like 4 (DLL4), deoxyribonucleic acid (DNA), endoplasmic reticulum (ER), farnesoid X receptor (FXR), fatty acids (FAs), fatty acid-binding protein 1 (FABP1), fatty acid-binding protein 2 (FABP2), follicle-associated epithelium (FAE), forkhead box protein P3 (FOXP3), neonatal fragment crystallizable receptor (FcRn), gastrointestinal tract (GIT), glucan microparticles (GMs), gut associated lymphoid tissues (GALT), hepatitis B surface antigen (HBsAg), high-density lipoprotein (HDL), high endothelial venules (HEVs), high performance liquid chromatography (HPLC), high-temperature requirement A serine protease (HtrA protease), human immunodeficiency virus (HIV), immune stimulating complexes (ISCOMs), immunoglobulin A (IgA), indocyanine green (ICG), inflammatory bowel diseases (IBDs), interleukin 10 (IL-10), interferon regulatory factor 4 (IRF4), intravenous (IV), invariant natural killer T-cell (iNKT), isolated lymphoid follicles (ILFs), lecithin cholesterol acyl transferase (LCAT), lipid nanoparticles (LNPs), lymphatic endothelial cells (LECs), lyso-phosphatidylcholine (LPC), lyso-phospholipids (lyso-article has not been copyedited and formatted. The final version may differ from this version.