Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human T-cell leukemia-lymphoma virus (HTLV) is a human C-type retrovirus that can transform T lymphocytes in vitro and is associated with certain T-cell neoplasms. Recent data suggest that, in the United States, patients with acquired immunodeficiency syndrome (AIDS), homosexual men with lymphadenopathy, and hemophiliacs have had significant exposure rates to HTLV, whereas matched and unmatched control American subjects have rarely been exposed to this agent. In the present experiments, T cells specifically reactive against HTLV were propagated from a patient whose HTLV-bearing lymphoma was in remission. The T cells were cloned in the presence of the virus and an HTLV-specific cytotoxic T-cell clone was isolated. This clone was infected and transformed by the virus, with one copy of an HTLV-I provirus being integrated into the genome. This T-cell clone did not exhibit the normal dependence on T-cell growth factor (interleukin-2) and proliferated spontaneously in vitro. Exposure of the clone to HTLV-bearing, autologous tumor cells specifically inhibited its proliferation and resulted in its death. These results may have implications for HTLV-associated inhibition of T-cell responses.
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PMID:Transformation and cytopathogenic effect in an immune human T-cell clone infected by HTLV-I. 632 99

The production of T-cell growth factor (TCGF) by acute lymphoblastic leukaemia (ALL) cells was determined in seven children and in three adults. A significant production of TCGF by adult, but not childhood, ALL cells was observed. The adult ALL cells were classified as "non-T-non-B" by surface marker analysis. It is suggested that TCGF production may not be confined to the cells of T-lineage.
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PMID:T-cell growth factor production by adult, but not childhood. Acute lymphoblastic leukaemic cells. 633 39

The unique hormonal characteristics of human interleukin 2 (IL 2), primarily the high affinity of the IL 2-receptor interaction, created several impediments to the generation of monoclonal antibodies to this lymphokine. Because normal cell sources produce only a few micrograms of IL 2 per liter, it was necessary to utilize high producer clones and subclones of a human T leukemia cell line to obtain immunogenic amounts of IL 2 protein. Moreover, assays that required antibody-mediated intervention of the high affinity IL 2-receptor binding were ineffectual in the identification of anti-IL 2-producing hybridomas, thus necessitating the development of immunoassays. Two of three initially derived antibodies detected by enzyme-linked immunoassay were found to react specifically with IL 2 as demonstrated by antibody concentration-dependent neutralization of IL 2 activity. The neutralization of cellular proliferation was specific for IL 2-reactive cells, coincided with an inhibition of IL 2 receptor binding, could be completely overcome by affinity-purified IL 2 and was species-specific; human and murine IL 2 were neutralized, whereas rat IL 2 activity remained unaffected. A third antibody, although much less effective in neutralizing IL 2 activity, bound to IL 2 more avidly and functioned as an efficient immunoabsorbent. IL 2 could be concentrated and purified by immunoabsorption from crude conditioned medium in a single step. The purified product, which retained biologic activity, was made up of a single protein (Mr = 15,500) as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, reversed-phase liquid chromatography, and amino-terminal amino acid sequence analysis. These results indicate that the distinctive biochemical and functional properties of individual lymphokines may well determine the efficiency with which antibodies may be elicited and detected. However, once produced, anti-lymphokines are uniquely suited for the exploration of the molecular and biologic properties of these immunoregulatory molecules.
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PMID:Production and characterization of monoclonal antibodies to human interleukin 2: strategy and tactics. 635 4

Anti-Tac monoclonal antibody, which blocks the membrane binding and action of human T-cell growth factor (TCGF), is strongly proposed to recognize TCGF receptor. We have demonstrated that anti-Tac antibody reacted with leukemic cells from patients with adult T-cell leukemia (ATL) and reacted with T-cell lines established from ATL cells. Although antigenic modulation, or down-regulation, of Tac antigen on activated normal T cells was induced by anti-Tac antibody, the expression of Tac antigen on ATL cells or T-cell lines was not affected when examined by the fluorescence-activated cell sorter (FACS) and the radioassay using 125I-staphylococcal protein A. These results indicate that regulation of Tac antigen-TCGF receptor is different between normal and malignant T cells, suggesting that failure of down-regulation of Tac antigen on leukemic cells by anti-Tac antibody may play an important role in the malignant proliferation of ATL cells.
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PMID:Failure of regulation of Tac antigen/TCGF receptor on adult T-cell leukemia cells by anti-Tac monoclonal antibody. 640 81

Human T (thymus-derived)-cell leukemia/lymphoma virus (HTLV) is a new retrovirus first isolated from T-cell lines from a patient with cutaneous T-cell lymphoma from the southeastern United States. Closely related viruses have since been isolated from several patients with adult T-cell leukemia and lymphoma (and some normal persons) from different areas of the world. HTLV is not a genetically transmitted endogenous virus of humans, but it rather is acquired by postzygotic infection. Natural antibodies to several purified viral proteins have been observed in infected individuals. HTLV is transmissible in vitro to human cord blood T cells, and infection results in an increased growth rate, a reduced requirement for (and often independence from) T-cell growth factor, and an abrogation of the crisis period that usually occurs a month after the establishment of normal T-cell cultures. These data suggest that HTLV is the etiologic agent in some human cases of leukemia and lymphoma.
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PMID:Human T-cell leukemia/lymphoma virus: the retrovirus of adult T-cell leukemia/lymphoma. 660 Nov 68

We have identified a Japanese patient with adult T-cell leukemia (ATL) whose T cells in vitro produced the human T-cell leukemia virus (HTLV). This patient presented with lymphomatous arthritis and leukemia and subsequently developed skin lesions. Skin invasion by malignant T-cells was angiocentric and produced vessel wall destruction, resulting in necrotic cutaneous tumor nodules. Malignant T cells in peripheral blood, skin, and joint prior to culture in vitro did not express p19 HTLV-associated antigen. However, by electron microscopy, intracellular type C viral particles were seen in skin-infiltrating T cells. Peripheral blood malignant cells after 7 days in culture with T-cell growth factor-supplemented media expressed p19 antigen, and type C virus particles were seen by electron microscopy to be budding from malignant T lymphocytes. Mitomycin-C-treated peripheral-blood T cells induced the transformation of cord blood T cells into HTLV-infected p19+ T cells. The demonstration of HTLV in malignant T cells from our patient confirms the association of HTLV with Japanese adult T-cell leukemia. Moreover, HTLV may be associated with a vasculitis-arthritis syndrome.
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PMID:Identification of human T cell leukemia virus in a Japanese patient with adult T cell leukemia and cutaneous lymphomatous vasculitis. 660 Dec 76

The acquired immune deficiency syndrome (AIDS) is characterized by T-lymphocyte dysfunction and is frequently accompanied by opportunistic infections and Kaposi's sarcoma. Human T-cell leukemia virus (HTLV) is associated with T-cell malignancies and can transform T lymphocytes in vitro. In an attempt to find evidence of HTLV infection in patients with AIDS, DNA from samples of peripheral blood lymphocytes from 33 AIDS patients was analyzed by Southern blot-hybridization with a radiolabeled cloned HTLV DNA probe. Analysis of DNA from both the fresh (uncultured) lymphocytes and from T cells cultured with T-cell growth factor revealed the presence of integrated HTLV proviral sequences in lymphocytes from two of the patients, both of whom had antibody to HTLV. The proviral sequences could not be detected in blood samples obtained from these individuals at a later date, consistent with the possibility that the population of infected cells had become depleted.
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PMID:Proviral DNA of a retrovirus, human T-cell leukemia virus, in two patients with AIDS. 660 22

Several isolates of a human type-C retrovirus belonging to one group, known as human T-cell leukemia virus (HTLV), have previously been obtained from patients with adult T-cell leukemia or lymphoma. The T-cell tropism of HTLV and its prevalence in the Caribbean basin prompted a search for it in patients with the epidemic T-cell immune deficiency disorder known as AIDS. Peripheral blood lymphocytes from one patient in the United States and two in France were cultured with T-cell growth factor (TCGF) an shown to express HTLV antigens. Virus from the U.S. patient was isolated and characterized and shown to be related to HTLV subgroup I. The virus was also transmitted into normal human T cells from umbilical cord blood of a newborn. Whether or not HTLV-I or other retroviruses of this family with T-cell tropism cause AIDS, it is possible that patients from whom the virus can be isolated can also transmit it to others. If the target cell of AIDS is the mature T cell as suspected, the methods used in these studies may prove useful for the long-term growth of these cells and for the identification of antigens specific for the etiological agent of AIDS.
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PMID:Isolation of human T-cell leukemia virus in acquired immune deficiency syndrome (AIDS). 660 23

Three patients with pre-adult T-cell leukemia (ATL) are reported. All of them were seropositive to ATL-associated antigens (ATLA) and had 3-30% abnormal lymphocytes with cleaved or lobulated nuclei in the peripheral blood in the absence of clinical symptoms of ATL. All the data on immunological tests were normal except for negative purified protein derivative skin tests. In Case 1 the patient was an elder sister of an ATL patient. Four other members of this family were also anti-ATLA positive without abnormal cells in the blood. In Cases 1 and 2, ATLA and ATL virus (ATLV) were expressed in the lymphocytes cultured with phytohemagglutinin or T-cell growth factor. Moreover, an ATLV-producing cell line was established from Case 1 by mixed lymphocyte culture with lymphocytes obtained from a normal anti-ATLA negative person. Investigation of pre-ATL cases may clarify factors leading to the development of ATL in ATLV-infected persons.
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PMID:Three cases of pre-adult T-cell leukemia. 660 29

Serum and peripheral blood cell samples from eleven relatives of a T-cell leukemia patient with human T-cell leukemia/lymphoma virus (HTLV)-associated disease, were investigated for the presence of HTLV antibody and antigen expression. In addition to the patient, three family members were seropositive and a wide range in HTLV antibody titer was observed. The father of the patient showed the highest titer (173,000) and carried HTLV p19+ cells in his peripheral blood. Upon induction of proliferation of these cells by short-term culture in the presence of phytohemagglutinin (PHA) and 12-O-tetradecanoyl phorbol-13-acetate (TPA), an increase from 1% to 28% HTLV p19+ cells was observed confirming previous findings that HTLV p19 expression was correlated with proliferative activity of the host cells. In none of the other seronegative or seropositive relatives of the patient HTLV p19 expression was revealed when tested in freshly isolated mononuclear cells, upon short-term incubation in PHA + TPA or after prolonged culture for 2 or 3 passages in medium containing T-cell growth factor. The results from HLA typing studies did not provide any evidence for HTLV related abnormalities in haplotype expression. Our data confirmed the earlier notion of a prevalence of HTLV infection within families of patients with HTLV-associated disease. It is furthermore obvious from our results that a normal individual may possess high titer HTLV antibody and circulating HTLV p19+ cells without showing signs of disease.
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PMID:Antibodies against human T-cell leukemia/lymphoma virus (HTLV) and expression of HTLV p19 antigen in relatives of a T-cell leukemia patient originating from Surinam. 660 35


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