In utero transplantation of human hematopoetic stem cells into fetal goats under B-type ultrasonographic scan: an experimental model for the study of potential prenatal therapy

Objective: Using fetal goats as animal models, to establish the methodology of in utero transplantation of human hematopoeitic stem cell (HSC) under B-scan ultrasonographic guidance for prenatal therapy. Study design: Human HSC were directly injected into the peritoneal cavities of the recipient fetal goats at 45-55 days of gestation (term: 145 days) under the guidance of B-type ultrasound scan. After birth, the peripheral blood was collected for fluorescence assisted cell sorting (FACS), quantitative real-time PCR and fluorescence in situ hybridization (FISH) to detect and analyze the presence of human cells in the recipients. Results: The 32 recipients were born alive except one miscarriage. To test for the presence of human-goat chimeras, cells from 13 randomly selected transplanted goats were collected. FACS analyses showed the presence of human cells in all the transplanted goats tested. The average proportion of CD34+ cells and GPA+(glycophorin A) cells in the peripheral blood were 1.34 ± 1.10% and 2.80 ± 2.10%, respectively. No CD34+ or GPA+ cells were found in the non-transplanted goats tested. The results of the quantitative real-time PCR in three engraftment goats were 1.2 × 104, 2.9 × 104, and 3.2 × 104 copies of human GPA DNA per μg of genomic DNA. FISH experiments showed that cells containing human specific α-satellite DNA sequence were present in the peripheral blood of the transplanted goats. Conclusions: The method described herein is safe and reliable, with low miscarriage risk and high chimerism rate. This approach may provide a promising animal model for potential prenatal treatment.