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We have studied the pattern of expression of the lymphokines tumor necrosis factor (TNF alpha) and lymphotoxin (TNF beta) in T-cell lines established by transformation with human T-lymphotropic virus, type I (HTLV-I), the etiologic agent of adult T-cell leukemia (ATL). We report here that nine of nine HTLV-I-infected T-cell lines, established by in vitro infection with HTLV-I, including those with CD4+ or CD8+ as well as CD4-/CD8- phenotypes, constitutively produce high levels of TNF alpha and -beta mRNA and secrete biologically active TNF beta into the culture medium. Similar patterns of expression are seen in six of six HTLV-I-infected T-cell lines directly established from ATL patients. In contrast, several T-cell lines, either uninfected or infected with human immunodeficiency virus I, did not produce comparable levels of the TNF beta. Comparisons of a normal functional T-cell clone before and after infection with HTLV-I show that expression of TNF beta mRNA is induced in the infected cells. The high level expression in HTLV-I- infected cell lines dose not seem to involve perturbation of the TNF alpha/beta genetic loci by proviral integration. A cell line (81–66/45) nonproductively transformed with HTLV-I that produces tat-1 in the absence of viral structural proteins, produces both TNF alpha and -beta mRNA. This suggests that expression of these cytokines could be mediated in trans by the tat-1 gene product.

Some laboratory results and clinical situations suggest that human T cells may be important in the regulation of growth of hematopoietic cells. Since the discovery of T-cell growth factor (TCGF), systems are now available for the long-term specific in vitro propagation of mature normal or neoplastic human T cells, providing an opportunity to study the influence of T cells on hematopoiesis. Recently, 24 cell lines from patients with cutaneous T-cell lymphoma (CTCL) and T-cell acute lymphoblastic leukemia (T-ALL) were grown with TCGF and then assessed for release of humoral factors that affect hematopoiesis. Conditioned media (CM) from these cell lines were tested for erythroid burst- promoting activity (BPA) and granulocyte colony-stimulating activity (CSA). BPA was detected in CM from 3/6 cultures of T-ALL patients and 4/6 CTCL cultures. CSA was found in the CM from 6/8 cultures of T-ALL patients, 7/12 CTCL cultures, and 3/4 CTCL cell lines that become independent of exogenous TCGF for growth. The CSA from several of the neoplastic T-cell cultures stimulated high levels of eosinophil colonies, a possible source of the eosinophilia seen in these patients. The ability of continuously proliferating human T lymphocytes, which retain functional specificity and responsiveness to normal humoral regulation, to produce factors that directly or indirectly stimulate myeloid and erythroid colony formation lends further credence to the role of T lymphocytes in regulating hematopoiesis.

A method is described that allows for the routine long-term (greater than 3 mo) growth of normal, immature human myeloid cells in liquid suspension culture. The techniques employ cell separation, utilization of special growth conditions (RPMI with hydrocortisone and vitamin D), and cord blood as the source of leukocytes. These cultures are composed predominantly of immature myeloid cells that have grown for over 3 mo in culture but eventually terminate as differentiated, mature granulocytes and monocyte-macrophages. Application of these techniques to other sources of fresh human leukocytes (bone marrow and adult peripheral blood) resulted in only short-term proliferation of myeloid cells. The techniques described can be used for the routine expansion of immature myeloid and monocytoid cell populations, particularly from newborns, and should be useful for systematic studies of normal myeloid- monocytoid cell growth and differentiation and providing normal control cells in studies employing human leukemic myeloid cells.

The discovery of T-cell growth factor (TCGF) has made it possible to now routinely grow in tissue culture normal and neoplastic human T cells for long periods and in large amounts. TCGF has been recently purified. It is a small protein released by a subset of mature T cells following lectin-antigen activation, which in turn acts upon other T- cell subsets that have developed specific receptors for TCGF after lectin-antigen stimulation. Thus, release of TCGF and development of receptors for it appear to be obligatory for the clonal expansion of all activated T cells. Unlike normal T cells, neoplastic T cells respond directly to TCGF, requiring no prior in vitro lectin-antigen activation. This has led to the development of several new cell lines from patients with T-cell leukemias and lymphomas. In some cases, these cells become independent of exogenous TCGF by producing their own growth factor, implying a role for TCGF in the continuous proliferation of these cells. These developments necessitate a reevaluation of some concepts of immunoregulation of T-cell activities in terms of production and response to TCGF. In addition, this information has clinical implications. Recent results have shown that a major defect of the athymic nude mouse is the inability to produce TCGF and that some immunosuppressive agents, such as glucocorticosteroids and cyclosporin- A, exert their effects on T cells by disrupting the TCGF-T-cell interaction. Some human immune deficiencies might be due to a failure to respond to or to produce TCGF, which in some cases might be corrected by exogenous TCGF.

The human T-cell leukemia/lymphoma virus (HTLV) is a novel type-C retrovirus isolated from patients with T-lymphoproliferative malignancies. Thirteen cases of HTLV-associated malignancy from US centers were studied in detail. Ten of these cases share common clinical features and define a typical virus-associated adult T-cell leukemia/lymphoma (ATL). All ten patients presented with Ann Arbor stage IV lymphoma because of skin involvement, bone marrow involvement, or lymphomatous leptomeningitis. Lymphadenopathy occurred in 7 of 10 patients at presentation, and the malignant cells were cytologically pleomorphic. Leukemia occurred in 60% of the patients at presentation. Hypercalcemia was found initially in two-thirds of the patients, with lytic bone lesions or positive bone scans in 7 of 10. Complete remission occurred in 40%, but all have relapsed. These cases closely resemble those virus-positive cases of adult T-cell leukemia/lymphoma (ATL) reported from Japan and the Caribbean. Three additional virus- positive patients had atypical presentations and diagnoses (acute lymphocytic leukemia, Sezary's syndrome, leukemic reticuloendotheliosis), usually with less aggressive clinical courses and atypical demographic and laboratory features. Presence of HTLV serum antibodies in cases of ATL (with hypercalcemia and circulating malignant cells) appears to define a distinct clinicopathologic entity that may occur in geographic clusters.

The recent development of two continuously proliferating human myeloid leukemic cell lines (HL-60 and KG-1) that response to CSA provides an opportunity for a detailed study of the interaction of CSA with leukemic myeloid cells. Here we report on the colony-forming ability of HL-60 and KG-1 over an extended culture life of the cells. Several different sources of human CSA of different stages of purity enhanced colony formation of these cells. CSA, obtained from conditioned media from an SV-40 transformed human trophoblast, was partially purified, and its activity for normal bone marrow copurified with the activity that stimulated HL-60 colony formation. Over 100 clones of HL-60 were developed and tested for their response to CSA. All responded to CSA by showing an increase in colony size and number. However, none of the colonies formed from any of the 100 clones differentiated in response to CSA despite the fact that many chemical can induce differentiation of HL-60. since HL-60 forms spontaneous colonies without the addition of any exogenous stimulating factors, HL-60 conditioned media and cell extracts were tested for the production by these cells of their own endogenous growth-promoting activity (such as a CSA-like molecule). No growth-promoting endogenous activity was found that stimulated normal bone marrow or HL-60 colony formation even after concentration and fractionation methods were employed. These experiments suggest that: (1) the effect of CSA markedly favors proliferation over differentiation in these cell lines; (2) CSA is unlikely to suppress growth of the age of the type of leukemic myeloid cells that HL-60 and KG-1 represent; and (3) if HL-60 cells produce their own growth- promoting factor it is not detectable in the media.

Peripheral mononuclear cells (MNC) collected from 12 healthy donors and 44 leukemic patients at various stages of the disease were tested for natural killer (NK) activity and for their susceptibility to HTLV-I infection in vitro, measured in terms of percentage of p19 positive cells. MNC from leukemic donors at any stage of leukemia (ie, onset or relapse, ON/REL; complete remission or off-therapy, CR/OT donors) were highly susceptible to HTLV-I infection. This was true for acute leukemias of lymphoblastic (ALL) or nonlymphoblastic (ANLL) type. MNC of ON/REL patients were more susceptible to HTLV-I than those of CR/OT donors. In addition, leukemic blasts were more rapidly infected (ie, within five to seven days) than the HTLV-I-susceptible normal cord- blood lymphocytes. However, the presence of circulating blasts was not essential to virus susceptibility, since CR/OT MNC, presumably free of leukemic blasts, were still more susceptible to HTLV-I than normal cells. Basal NK function of MNC from leukemic patients was significantly lower than that detectable in healthy controls. However, no correlation was found between susceptibility to HTLV-I infection and NK activity.

The human T-cell lymphotropic virus type III (HTLV-III) is the etiologic agent of the acquired immunodeficiency syndrome (AIDS) and preferentially infects T4 lymphocytes. Other cell types, notably B lymphocytes and other nonlymphoid cells, also have been reported to be infected in vitro by HTLV-III. We now report on the susceptibility of human pulmonary macrophages to infection with HTLV-III in vitro. Alveolar macrophages infected with HTLV-III produced low levels of virus that could be transferred to allogeneic human peripheral blood mononuclear leukocytes as long as 2 weeks after initiation of infection. Unlike HTLV-III infection of T lymphocytes, macrophages appeared more resistant to viral-mediated cytopathic effects. Primary cultures of pulmonary macrophages from two of four patients with AIDS spontaneously produced low levels of virus detected as precipitable reverse transcriptase activity, suggesting that these cells were infected in vivo. Because tissue macrophages are long-lived cells, they may act as a reservoir of HTLV-III, capable of transmitting the virus to other susceptible cells such as T lymphocytes, causing periodic low- level viremia. Macrophage infection with HTLV-III may be one mechanism for the establishment of viral persistence in infected hosts.

Lymphoma occurs at increased frequency in patients with the acquired immunodeficiency syndrome (AIDS). We studied, using serologic and molecular techniques, one such lymphoma for (a) evidence of infection with human T lymphotropic virus, type III (HTLV-III), and Epstein-Barr virus (EBV), (b) monoclonal rearrangement of immunoglobulin and T cell receptor genes, and (c) rearrangement of the c-myc oncogene. Immunoglobulin and T cell receptor gene studies demonstrated that the tumor was of monoclonal B cell origin. Similar to cases of Burkitt's lymphoma unrelated to AIDS, there were DNA sequences in the lymphoma that hybridized to EBV-specific probes and demonstrated evidence of c- myc rearrangement. HTLV-III sequences were not detected in the malignant B cells. The pathogenesis of some B cell neoplasms in patients with the syndrome may involve transformation by EBV and deregulation of oncogene expression without direct infection of the malignant B cells by HTLV-III.

The third member of the family of T cell leukemia viruses (HTLV III) has been proposed as the primary etiologic agent of the acquired immunodeficiency syndrome (AIDS). A high risk of AIDS has been reported among patients with hemophilia, particularly those with factor VIII deficiency who receive commercial clotting factor concentrates. In a prevalence survey conducted between September 1982 and April 1984, initial serum samples from 74% of hemophiliacs who had ever been treated with commercial factor VIII concentrate, 90% of those frequently treated with factor VIII concentrate, and 50% of those treated with both factor VIII and factor IX concentrates had antibodies reactive against antigens of HTLV III, compared with none of the hemophiliacs treated only with factor IX concentrate or volunteer donor plasma or cryoprecipitate. Two of the seropositive patients have developed AIDS-related illnesses, and a third patient died of bacterial pneumonia. One initially seronegative patient developed antibodies against HTLV III during the study and is currently well. The predominant antibody specificities appear directed against p24 and p41, the presumed core and envelope antigens of HTLV III, suggesting that factor VIII concentrate may transmit the p24 and p41 antigens of HTLV III. However, the presence of infectious retroviruses in clotting factor concentrates and the effectiveness of screening and viral neutralization procedures remain to be determined.

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).

At least three distinct DNA polymerases, named alpha, beta, and gamma, have been isolated from normal mammalian cells. The function of these enzymes in regard to DNA replication and repair remains unclear. Stimulation of blood lymphocytes with the plant mitogen phytohemagglutinin (PHA), is known to increase total DNA polymerase activity. In this study, we measured the change of each of these activities as lymphocytes intered a mitotic cycle. Aliquots of a pool of normal human blood lymphocytes were incubated with PHA for 0, 24, 48, and 72 hr, respectively, and the various DNA polymerase activities quantitated at each point. No significant DNA polymerase activity was detected in unstimulated cells. Low levels of polymerase beta were found at 24 hr. The average DNA content per cell doubled between 24 and 48 hr, and during this interval all three DNA polymerases increased to easily detectable levels. By far the greatest fractional increase in activity of all three polymerases was seen between 48 and 72 hr, after the average doubling of cellular DNA. In summary, these blood lymphocytes lack significant levels of DNA polymerases; stimulation with PHA induces all three of the major DNA polymerase species. In both these respects, these cells differ from other proliferating mammalian cell systems. The possible significance of this difference is discussed.

We investigated 18 sets of blood donors from 12 to 50 months after they donated blood to recipients who subsequently developed the acquired immunodeficiency syndrome (AIDS). Within each donor set, only one donor was suspected of having transmitted the disease (ie, member of an AIDS risk group). The other donors (n = 189) were not risk group members and served as controls. A number of laboratory tests distinguished suspected from nonsuspected donors, including determination of T helper/T suppressor cell ratio, antibody to hepatitis B core antigen, and immune complexes, but none of these was as sensitive and specific as tests for antibody to the human retrovirus, HTLV-III/LAV.

Colony-stimulating activity (CSA) is a class of protein factors that stimulates the in vitro growth and differentiation of hematopoietic committed stem cells into mature granulocytes and macrophages. In man, production of CSA is mediated by monocytes-macrophages, lymphocyte, and endothelial cells. One of the best studied and most potent sources of CSA is conditioned media derived from cultured human placenta. The cellular source of this placental CSA was studied using cloned term placental cell lines induced by a simian virus 40 (SV-40) Wild-Type (wt) or temperature sensitive (tsA) mutants. Conditioned media from SV- 40 wt-transformed placental cells grown at 37 degrees C and tsA- transformed placental cells grown at 33 degrees C (the temperature at which the cells exhibit the transformed phenotype) and at 40 degrees C (temperature at which the cells express a normal differentiated phenotype) contained high levels of CSA. At the restricted temperature (40 degrees C), these cell lines expressed normal trophoblastic characteristics in that they produced human chorionic gonadotropin, pregnancy-specific-beta1-glyco protein, and placental alkaline phosphatase, indicating that the SV-40 transformation has not interfered with normal cellular functions of these trophoblasts. The CSA released by these cell lines resemble those of CM from fresh placental cells, in that the level of activity is high and that formation of both granulocyte/macrophage and eosinophil colonies is stimulated.

Terminal deoxynucleotidyl transferase, an enzyme which catalyzes the polymerization of deoxyribonucleoside triphosphates, elongating oligo- or polydeoxynucleotide chains, but without direction from a nucleic acid template, is thought to be specific for thymus gland and thymus- derived cells. We have confirmed the observations that high levels are characteristic of thymus gland with both human and calf tissue and that elevated levels may be found in some cases of acute lymphocytic leukemia. High levels were also found in human lymphoblast cell lines with T-cell characteristics, and insignificant activity was observed in leukocytes of patients with chronic myelogenous leukemia not in acute blast phase of the disease, chronic lymphocytic leukemia, human B- cells, and normal human blood lymphocytes even after stimulation with phytohemagglutinin. However, high levels (approximately 200 nmoles/hr/10(9) cells) equivalent to those in thymus tissue and lymphoblast cell lines with T-cell characteristics were found in the peripheral blood blast cells of four patients with chronic myelogenous leukemia in an acute blast phase of their disease. One hypothesis that may explain the present results is that in chronic myelogenous leukemia in acute blast phase of the disease the proliferative blast response may not always be myeloblasts but in some cases it may be lymphoblasts.

Three cell lines of mature T cell origin derived from patients with cutaneous T cell lymphoma-leukemias (CTCL) were found to be constitutive producers of T cell growth factor (L-TCGF). These are the first reported human cell lines which constitutively produce TCGF. Biologically active TCGF could also be eluted from the surface of these cells using an acid glycine buffer under conditions that maintained cell viability, and subcellular fractionation showed that almost all the TCGF activity was associated with the plasma membrane. Over 30 other human hematopoietic cell lines derived from other disorders were unable to produce TCGF even after induction, and their acid eluates did not contain TCGF activity. L-TCGF from CTCL lines had the same biological activity as TCGF obtained from normal leukocytes (N-TCGF) in that they both supported the long-term growth of normal T cells only after the cells were previously activated by antigen or lectin. Both L-TCGF and N-TCGF increased the rate of proliferation of TCGF-independent and TCGF-dependent CTCL cell lines. The same three factor-independent cell lines that released TCGF adsorbed TCGF in a cell-concentration, time-, and temperature-dependent manner. Since the CTCL cell lines produce TCGF, adsorb TCGF, and increase their proliferative rate in response to TCGF or a related molecule, it is suggested that this endogenously produced factor plays a role in maintaining the abnormal proliferation of these cells in culture as permanently growing cell lines independent of exogenous TCGF. However, this does not mean that this is an essential aspect of neoplastic transformation. Since it is unusual to develop these cell lines in the absence of the continuous need for added TCGF, "autostimulation" may be one of the many unusual variant phenotypic properties sometimes associated with neoplastic cells that gives them a selective advantage for in vitro growth.