Volume 31, Number 5—May 2025
Dispatch
Administration of L-Type Bovine Spongiform Encephalopathy to Macaques to Evaluate Zoonotic Potential
Figure 3

Figure 3. Gel electrophoresis and Western blot testing of tissues obtained from macaques orally inoculated with L-BSE prions in study of oral transmission of L-BSE in macaques to evaluate zoonotic potential. We loaded each 6th-round protein misfolding cyclic amplification (PMCA) product, seeded with tissues obtained from the 2 macaques (#18 and #19), onto 2 gels for sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by Western blot. A) PMCA products amplified from ML, To, Sp, and Il; B) PMCA products amplified from CC, TC, MN, SG, and Th; C) Western blot analysis. For comparison, PMCA products amplified using BH obtained from macaque #23, intracerebrally inoculated with L-BSE, were run on both gels together with products amplified from the ileum of macaque #18. Abnormal prion protein (PrP)-like proteinase K–resistant prion proteins (PrPres) from L-BSE orally inoculated macaques exhibited a few distinct banding patterns, which differed from those of PrPres from L-BSE intracerebrally in macaque #23. For Western blot, we compared 6th-round PMCA products, seeded with IL tissue obtained from macaque #18 and Br tissue obtained from macaque #23, L-BSE–affected cattle, C-BSE–affected cattle, and H-BSE–affected cattle. Banding results represent the products of PMCA using the BHs of wild-type mice (upper image) and bovine normal prion protein–expressing transgenic mice (lower image) as substrates, with identical cofactors. Among the PrPres amplified from the ileum of L-BSE/PO macaque #18, the banding pattern of PrPres with a small molecular weight (low) was very similar to that of PrPres amplified from the brain of cattle inoculated intracerebrally with C-BSE. BH, brain homogenate, BoTg, bovine normal prion protein–expressing transgenic; Br, brain; C-BSE, classical bovine spongiform encephalopathy; CC, cervical cord; H-BSE, H-type bovine spongiform encephalopathy; IC, inoculated intracerebrally; Il, ileum; IL, inguinal lymph nodes; L-BSE, L-type bovine spongiform encephalopathy; Mac, macaque; ML, mesenteric lymph nodes; MN, median nerve; PO, inoculated orally; SG, submaxillary gland; Sp, spleen; TC, thoracic cord; Th, thymus; To, tonsil.
1These authors were co–principal investigators.