In terms of differences, AD169 has been extensively passaged, and lacks a large number of genes in the UL/b' region of the genome, as well as elsewhere in the genome. There are at least 2 variants of AD169 in common use around the world - referred to as VAR-ATCC & VAR-UK.

TB40/E and TB40/F were originally derived from the same clinical material, but were passaged largely on endothelial (E) cells or fibroblast (F) cells. Each variant has adapted genetically. Amongst these changes are differences in tropism - TB40/E is the only one that efficiently infects epithelial/endothelial cells.

All 3 will grow in fibroblasts, and these cells are commonly used to make stocks of them. AD169 & TB40/F won't efficiently infect epithelial/endothelial cells, but TB40/E will.

HCMVs mainly use monocytes as their favourite infection point, and the monocytes become the sites for viral latency, and also as dissemination centers.

Strains of the HCMV may be endotheliotropic (Having affinity for endothelial cells) or non endotheliotropic

TB40E is an endotheliotropic strain of HCMV which infects monocytes and impairs their chemokine-driven migration.They rapidly downregulate surface chemokine receptors on the monocyte surface.

AD169 is nonendotheliotropic and unable to induce chemokine receptor downregulation, and infected monocytes maintain responsiveness to inflammatory and homeostatic chemokines.

TB40F is a fibroblast adapted strain of TB40E obtained after fibroblast cultures of TB40E.It does not affect monocyte migration in the same way as TB40E, chemokine receptors are also relatively unaffected by this strain.

I should add that various AD169 strains have been fully sequenced. The full sequence of TB40/E has not been published, although the full sequence of a BAC clone (TB40-BAC4) derived from TB40/E has. Personally, for working in fibroblasts we use the Merlin strain - it's fully sequenced, and we have a BAC clone of it, so we know what state it's in genetically - it's got far fewer mutations than AD169. However many other labs do use TB40/E, or the TB40-BAC4 BAC clone.

I assume you would have the data as available on the following link?

http://vts.uni-ulm.de/docs/2012/8272/vts_8272_12127.pdf

It would be of benefit to you to contact the team for collaborative purposes.

Wish you success in your endeavour

Strains TB40/E and TB40/F were derived from a bone marrow transplant recipient by passaging in endothelial cells and fibroblasts. I suggest that you read the original publications from Sinzger et al. TB40F is a fibroblast adapted strain obtained after prolonged culture of TB40E in fibroblasts.You can definitely make stocks in fibroblasts. AD169 is a highly passaged fibroblast-adapted laboratory strain of HCMV.

Thank you for all replies. Taken all information together, now I can better understand the concepts.

By the way, the more clinical the strain, the more cell-associated it is (i.e. Merlin is more cell associated than TB40E, TB40E is more cell-associated than AD169).