June 28, 1982
Dear Harold:
As you know, there was a US-Japan workshop on adult human T cell malignancies in Seattle in March this year. In addition to the people who are working directly on the project, Dr. Max Essex and I were invited to attend the workshop as observers.
Toward the end of the meeting, U.S. group proposed ATL for the name of disease and HTLV for the name of viruses which are cross reactive to HTLV of Dr. Gallo's group. Japanese group shelved the answer since we had not discussed such problems. However, Max used the name HTLV in a draft of the report of this meeting although he made the comment to the effect that this nomenclature was only tentative and for avoiding confusion.
Dr. Sugano, the chairman of the Japanese group attending this workshop, and myself refused to use HTLV for the name of ATLV in this report, because we recognize both of these names as strain names at present. I wrote to Max about my idea on this point together with other comments on the meeting report.
The major points of my idea on nomenclature are as follows:
1) Generally, I would agree to avoid confusion about nomenclature, however 
over-simplification of nomenclature should be avoided also.
2) The possibility has not been completely ruled out that these viruses include some minor populations which have some genomic modifications and have higher oncogenicity. In vitro immortalization of lymphocytes by cocultivation with these virus producing T cell lines has been already established. On the other hand, similar phenomenon by other cells infected with other non-modified leukemia virus still remains obscure. If genomes have some modifications, they may be named by individual isolate.
3) HTLVs have been isolated from patients of Mycosis fungoides or Sezary syndrome, but no patient out of 6 Mycosis fungoides cases in non-endemic area in Japan was sero-positive for ATLV antigen complex.
4) Species name of leukemia viruses appeared to be composed of the species name of animal, "leukemia" and "virus" (i.e. ALV, BLV etc.). It is customary that type of specific tumor is not indicated in the species name of leukemia virus. On the basis of these considerations, the best species name of these viruses should be HLV (or HuLV).
5) Finally, prototype of this virus species must be, with no doubt, Dr. Gallo's isolate, because HTLV and ATLV are cross reactive.
I would like to hear from you on this problem either personally or as the chairman of nomenclature of retroviruses.
With best wishes.
Kumao Toyoshima