A historical reflection on the discovery of human retroviruses

The discovery of HIV-1 as the cause of AIDS was one of the major scientific achievements during the last century. Here the events leading to this discovery are reviewed with particular attention to priority and actual contributions by those involved. Since I would argue that discovering HIV was dependent on the previous discovery of the first human retrovirus HTLV-I, the history of this discovery is also re-examined. The first human retroviruses (HTLV-I) was first reported by Robert C. Gallo and coworkers in 1980 and reconfirmed by Yorio Hinuma and coworkers in 1981. These discoveries were in turn dependent on the previous discovery by Gallo and coworkers in 1976 of interleukin 2 or T-cell growth factor as it was called then. HTLV-II was described by Gallo's group in 1982. A human retrovirus distinct from HTLV-I and HTLV-II in that it was shown to have the morphology of a lentivirus was in my mind described for the first time by Luc Montagnier in an oral presentation at Cold Spring Harbor in September of 1983. This virus was isolated from a patient with lymphadenopathy using the protocol previously described for HTLV by Gallo. The first peer reviewed paper by Montagnier's group of such a retrovirus, isolated from two siblings of whom one with AIDS, appeared in Lancet in April of 1984. However, the proof that a new human retrovirus (HIV-1) was the cause of AIDS was first established in four publications by Gallo's group in the May 4th issue of Science in 1984

A reflection on HIV/AIDS research after 25 years

Dr. Robert C. Gallo provides a personal reflection on the 25 year history of AIDS

Isolation and characterization of a T lymphocyte-derived differentiation inducing factor for the myeloid leukemic cell line HL- 60

Abstract Mitogen-stimulated mononuclear blood cells produce differentiation inducing factors (DIFs) for the promyelocytic cell line HL-60. We report that DIF is produced constitutively by a malignant T lymphocyte line HUT-102. DIF was purified 7,000-fold from HUT-102 conditioned media by utilizing ion-exchange chromatography with DEAE-Sepharose, gel chromatography, Blue-Sepharose chromatography, and preparative SDS- polyacrylamide gel electrophoresis (SDS-PAGE). The final preparation is susceptible to protease treatment, has a molecular weight of 46,000, as determined by SDS-PAGE and approximately 55,000 by gel filtration, has an isoelectric point of approximately 5.2, does not adhere to lectin- Sepharose and is resistant to periodate oxidation, and is free of colony-stimulating factor. DIF induced maturation of HL-60 into phagocytizing nitro blue tetrazolium reducing cells with the morphological characteristics of myelomonocytic or monocyte-like cells. An activity, co-chromatographing with DIF, acts synergistically with retinoic acid to induce maturation not only of HL-60, but also of the monoblast-like cell line U-937 (measured as percentage of cells reducing NBT).</jats:p

T lymphocyte-derived differentiation-inducing factor inhibits proliferation of leukemic and normal hemopoietic cells

Abstract A differentiation-inducing factor (DIF) for the promyelocytic HL-60 cell line is constitutively produced by the malignant T lymphocyte line HUT-102. DIF was highly purified from HUT-102-conditioned media by means of diethylaminoethanol (DEAE)-chromatography, gel chromatography, and high-resolution, ion-exchange chromatography on a MonoQ column and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In addition to inducing differentiation of wild-type HL-60 cells, resulting in secondary inhibition of growth, DIF, at a tenfold lower concentration, inhibited the growth of some clones of the monoblastic U- 937 cell line as well as that of subclones of HL-60. The latter effect was most likely a primary growth inhibition and not secondary to differentiation; 50% inhibition of clonogenic growth in agar was seen at approximately 1.0 pmol/L of DIF. In addition, the clonogenic growth of fresh leukemia cells from 10 of 12 patients with acute myeloid leukemia (AML) was inhibited with 50% inhibition at approximately 10 pmol/L of DIF. The growth of normal granulocyte-macrophage colonies was inhibited at a similar concentration, whereas early erythroid colonies were much more resistant. DIF and interferon-gamma (gamma-IFN) were shown to be separate molecules inasmuch as a neutralizing antibody for gamma-IFN did not abolish the DIF effect. The differentiation effect on wild-type HL-60 and the proliferation inhibitory effect on leukemic and normal myeloid cells cochromatographed through all purification steps suggest that both activities are exhibited by identical polypeptides. DIF may have a role in regulating normal hemopoiesis. The growth inhibitory effect of DIF and the ability to induce differentiation of some leukemia cells may suggest a clinical utility in the treatment of leukemia.</jats:p

Isolation and characterization of a T lymphocyte-derived differentiation inducing factor for the myeloid leukemic cell line HL- 60

Mitogen-stimulated mononuclear blood cells produce differentiation inducing factors (DIFs) for the promyelocytic cell line HL-60. We report that DIF is produced constitutively by a malignant T lymphocyte line HUT-102. DIF was purified 7,000-fold from HUT-102 conditioned media by utilizing ion-exchange chromatography with DEAE-Sepharose, gel chromatography, Blue-Sepharose chromatography, and preparative SDS- polyacrylamide gel electrophoresis (SDS-PAGE). The final preparation is susceptible to protease treatment, has a molecular weight of 46,000, as determined by SDS-PAGE and approximately 55,000 by gel filtration, has an isoelectric point of approximately 5.2, does not adhere to lectin- Sepharose and is resistant to periodate oxidation, and is free of colony-stimulating factor. DIF induced maturation of HL-60 into phagocytizing nitro blue tetrazolium reducing cells with the morphological characteristics of myelomonocytic or monocyte-like cells. An activity, co-chromatographing with DIF, acts synergistically with retinoic acid to induce maturation not only of HL-60, but also of the monoblast-like cell line U-937 (measured as percentage of cells reducing NBT).</jats:p

T lymphocyte-derived differentiation-inducing factor inhibits proliferation of leukemic and normal hemopoietic cells

A differentiation-inducing factor (DIF) for the promyelocytic HL-60 cell line is constitutively produced by the malignant T lymphocyte line HUT-102. DIF was highly purified from HUT-102-conditioned media by means of diethylaminoethanol (DEAE)-chromatography, gel chromatography, and high-resolution, ion-exchange chromatography on a MonoQ column and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In addition to inducing differentiation of wild-type HL-60 cells, resulting in secondary inhibition of growth, DIF, at a tenfold lower concentration, inhibited the growth of some clones of the monoblastic U- 937 cell line as well as that of subclones of HL-60. The latter effect was most likely a primary growth inhibition and not secondary to differentiation; 50% inhibition of clonogenic growth in agar was seen at approximately 1.0 pmol/L of DIF. In addition, the clonogenic growth of fresh leukemia cells from 10 of 12 patients with acute myeloid leukemia (AML) was inhibited with 50% inhibition at approximately 10 pmol/L of DIF. The growth of normal granulocyte-macrophage colonies was inhibited at a similar concentration, whereas early erythroid colonies were much more resistant. DIF and interferon-gamma (gamma-IFN) were shown to be separate molecules inasmuch as a neutralizing antibody for gamma-IFN did not abolish the DIF effect. The differentiation effect on wild-type HL-60 and the proliferation inhibitory effect on leukemic and normal myeloid cells cochromatographed through all purification steps suggest that both activities are exhibited by identical polypeptides. DIF may have a role in regulating normal hemopoiesis. The growth inhibitory effect of DIF and the ability to induce differentiation of some leukemia cells may suggest a clinical utility in the treatment of leukemia.</jats:p