Table 3.
Brain and peripheral tissue samples bioassay results in Methionine 129 Human PrP–expressing mice (tgMet) for sCJD patients
| sCJD 1 (96–1999) | sCJD 2 (21/2006) | sCJD 3 (02/83) | sCJD 4 (03/20) | sCJD 5 (31/2009) | Negative control | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tissue | n/n0 | Suriv. time | Inf. tit estimates | n/n0 | Suriv time | Inf. tit estimates | n/n0 | Suriv time | Inf. tit estimates | n/n0 | Suriv time | Inf. tit estimates | n/n0 | Suriv time | Inf. tit estimates | n/n0 | Suriv time |
| Frontal cortex | 6/6 | 215 ± 8 | 107.2 (106.7, 107.7) | 5/5 | 201 ± 6 | 107.8 (107.2, 108.3) | 5/5 | 236 ± 9 | 106.4 (105.9, 106.9) | 6/6 | 225 ± 14 | 105.8 (105.4, 106.3) | 6/6 | 219 ± 18 | 106.1 (105.6,106.6) | 0/6 | > 750 |
| Cervical Lymph node | 0/6 | > 750 | – | 6/6 | 335 ± 47 | 103 (102.7, 103.4) | 0/6 | > 750 | – | 0/6 | > 750 | – | 2/6 | 294,326 | 102.9 (102.4,103.4) | 0/6 | > 750 |
| Tonsil | 0/6 | > 750 | – | 6/6 | 298 ± 21 | 104.2 (103.8, 103.7) | 0/6 | > 750 | – | 1/6 | 380 | 102 (101.2, 102.6) | 1/6 | 486 | 100.1 (10–0.9,101.2) | 0/6 | > 750 |
| Spleen | NA | – | 1/5 | 318 ± 21 | 102.5 (102.1, 102.9) | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 | |
| Thymus | NA | – | NA | – | NA | – | NA | – | 4/6 | 347 ± 19 | 102.2 (101.7,102.5) | 0/6 | > 750 | ||||
| Lung | 5/5 | 321 ± 21 | 103.3 (102.9, 103.8) | 0/6 | > 750 | – | 3/6 | 370 ± 98 | 100.5 (10–0.2, 101.2) | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 |
| Heart | 5/6 | 329 ± 43 | 102.9 (102.6, 103.3) | 5/6 | 381 ± 58 | 102.2 (101.9, 102.5) | 0/6 | > 750 | – | 0/6 | > 750 | – | 1/6 | 538 | 10–3.4 (10–4.5,10–2.2) | 0/6 | > 750 |
| Liver | 0/6 | > 750 | – | 0/6 | > 600 | – | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 |
| Kidney | 1/6 | 403 | 101.6 (100.5, 102.3) | 2/6 | 302,393 | 102.7 (102.2, 103.3) | 0/6 | > 750 | – | 1/6 | 381 | 101.9 (101.1, 102.4) | 0/6 | > 750 | – | 0/6 | > 750 |
| Salivary gland | 5/6 | 387 ± 61 | 102.1 (101.7, 102.5) | 4/6 | 367 ± 60 | 102.1 (101.6, 102.6) | 0/6 | > 750 | – | 0/6 | > 750 | – | 2/6 | 730,732 | 10–0.52 (10–1.8,101.1) | 0/6 | > 750 |
| Pancreas | 0/6 | > 750 | – | 2/6 | 291,331 | 102.8 (102.1, 102.6) | 0/6 | > 750 | – | 5/6 | 348 ± 63 | 102.7 (102.4, 103) | 1/6 | 477 | 100.1 (10–1.2,100.4) | 0/6 | > 750 |
| Thyroid | NA | – | 0/6 | > 750 | – | 0/6 | > 750 | – | 1/6 | 414 | 101.4 (100.2, 102.1) | 0/6 | > 750 | – | 0/6 | > 750 | |
| Adrenal gland | 3/6 | 526 ± 63 | 10–0.6 (10–1.1, 100.2) | 6/6 | 301 ± 9 | 104 (103.6, 104.5) | 5/6 | 333 ± 32 | 102.8 (102.5, 103.2) | 2/6 | 345,348 | 102.2 (101.8, 102.6) | 3/6 | 419 ± 89 | 100.1 (10–0.9,101.2) | 0/6 | > 750 |
| Bone marrow | 6/6 | 264 ± 11 | 104.4 (103.9,104.9) | 6/6 | 359 ± 38 | 101.6 (101.3, 101.9) | 3/6 | 409 ± 18 | 100.2 (100, 100.9) | 6/6 | 311 ± 19 | 102.7 (102.2, 103.1) | 6/6 | 316 ± 18 | 102.5 (102.1,102.9) | 0/6 | > 750 |
| Skeletal muscle | 1/6 | 485 | 10–1.4 (10–2.5, 10–0.2) | 5/5 | 304 ± 32 | 103.9 (103.4, 104.4) | 3/6 | 484 ± 81 | 10–0.2 (10–0.8, 100.5) | 0/6 | > 750 | – | 0/6 | > 750 | – | 0/6 | > 750 |
| Testis | NA | ||||||||||||||||
| Ovary | 0/6 | > 750 | – | NA | NA | 0/6 | > 750 | – | 0/6 | > 750 | |||||||
Tg Met mice were inoculated with homogenates (10% weight / volume) of tissues that had been collected post mortem from symptomatic sCJD patients (sCJD-1 to sCJD-5). All the sCJD patients were homozygous for methionine at codon 129 of the PRNP gene and displayed a type 1 abnormal PrP profile in their brain. Tissues from a methionine at codon 129 individual that was not affected with CJD (negative control) were also inoculated in tg Met. Mice were killed when they showed clinical signs of prion infection or after 750-days post-inoculation. Mice were considered prion infected when abnormal PrP deposition was detected in brain by Western Blot (PrPres -antibody Sha31 epitope YEDRYYRE). Survival times are presented as mean ± SD except when less than three animals were positive. In that case individual survival time of positive animals are reported. Infectious prion titres were estimated by using the method of Arnold et al. [4]. The method uses the probability of survival (attack rate at each dilution) and the individual mouse incubation time at each dilution to estimate infectious load. Infectious titres are given as estimated values
LD50 50% lethal dose with lower and higher boundaries of the CI95%, Suriv. survival, Inf infectious, n number of abnormal, PrP positive mice by western blot, n0 number of inoculated mice; NA not available, PrP prion protein, sCJD sporadic Creutzfeldt–Jakob disease; tit titre