THYMUS-CLONING ERRORS: Yesterday I posted an item about a human thymus being grown by Australian researchers. That’s what the news story I linked to said, but it appears to be wrong. Dr. Steve White of the University of Chicago sent this:

The researchers collected thymic stem cells from mice, not humans (the clonal populations were collected from 15.5 day old mouse embryos). The exact populations were R1 (CD45.MHC class II.MTS24-) and R2 (CD45.MHC class II.MTS24+) cells. These cells were separated from other cells by flow cytometry and then engrafted into mouse kidneys. Embryonic cells at 15.5 days old (mid gestation for a mouse) were used as it was felt that this represented a point at which thymus cells (technically, thymic epithelial cells) had differentiated into two component types for the developing thymus gland.

This is a remarkable study and deserved publication in Nature Immunology. But these were mouse cells, not human cells, and came from an embryo, not an adult. Hope this clarifies it for you.

Dr. White was kind enough to send me the PDF of the Nature article, and he’s right — it says rather clearly in the methodology section that mouse cells, not human cells, were involved.