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Mayr B, Hofecker G, Zimmer H, Schlerka G, Leitner K, Schleger W. Untersuchungen an peripheren Lymphozytenpopulationen leukoseinfizierter und leukosefreier Rinder. ACTA ACUST UNITED AC 2010. [DOI: 10.1111/j.1439-0450.1979.tb00841.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Stone DM, Norton LK, Davis WC. Spontaneously proliferating lymphocytes from bovine leukaemia virus-infected, lymphocytotic cattle are not the virus-expressing lymphocytes, as these cells are delayed in G(0)/G(1) of the cell cycle and are spared from apoptosis. J Gen Virol 2000; 81:971-81. [PMID: 10725423 DOI: 10.1099/0022-1317-81-4-971] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bovine leukaemia virus (BLV) is in the family of oncogenic retroviruses which includes human T cell leukaemia virus (HTLV). BLV infects B lymphocytes and induces a non-neoplastic persistent lymphocytosis (PL) of B lymphocytes in cattle. A characteristic of BLV- and HTLV-induced disease is spontaneous lymphocyte proliferation of cultured peripheral blood mononuclear cells (PBMC). To investigate the role of virus expression on lymphocyte survival and proliferation, we evaluated cell cycle position, apoptosis and virus expression on a single-cell basis of cultured PBMC from BLV-infected PL cattle, BLV-infected non-PL cattle and uninfected cattle. Results demonstrated that the majority of bovine B lymphocytes spontaneously entered G(2)/M of the cell cycle and died by apoptosis by 24 h post-culture, regardless of BLV infection or PL status. The spontaneous proliferation that characterizes PL cattle was primarily due to a small population of surviving B lymphocytes, but T lymphocytes also contributed. Viral protein expression was detectable in only 5-15% of cultured PBMC from PL cattle and the majority of these lymphocytes were delayed in cell cycle and spared from apoptosis. Unexpectedly, we determined that only 3% of the spontaneously proliferating lymphocytes expressed viral proteins. Previous reports show that spontaneous proliferation decreases when virus expression is suppressed. Together with our results, this suggests that virus expression by one population of B lymphocytes promotes proliferation of another population of B lymphocytes that does not express virus. This may be due to an effect of virus on CD4 T lymphocytes, as depletion of CD4 T lymphocytes significantly decreased spontaneous proliferation.
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Affiliation(s)
- D M Stone
- Department of Veterinary Microbiology and Pathology, Washington State University, PO Box 647040, Pullman, WA 99164, USA.
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Trueblood ES, Brown WC, Palmer GH, Davis WC, Stone DM, McElwain TF. B-lymphocyte proliferation during bovine leukemia virus-induced persistent lymphocytosis is enhanced by T-lymphocyte-derived interleukin-2. J Virol 1998; 72:3169-77. [PMID: 9525643 PMCID: PMC109775 DOI: 10.1128/jvi.72.4.3169-3177.1998] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bovine leukemia virus (BLV)-induced persistent lymphocytosis is characterized by a polyclonal expansion of CD5+ B lymphocytes. To examine the role of the cytokine microenvironment in this virus-induced B-lymphocyte expansion, the expression of interleukin-2 (IL-2), IL-4, IL-10, and gamma interferon (IFN-gamma) mRNA, was measured in stimulated peripheral blood mononuclear cells from persistently lymphocytotic BLV-infected cows, nonlymphocytotic BLV-infected cows, and uninfected cows. IL-2 and IL-10 mRNA expression and IL-2 functional activity were significantly increased when peripheral blood mononuclear cells from persistently lymphocytotic cows were stimulated with concanavalin A (ConA). Additionally, during persistent lymphocytosis, peak IL-2 and IL-10 mRNA expression was delayed, and elevated expression was prolonged. To determine the potential biologic importance of increased IL-2 and IL-10 expression, the response of isolated B lymphocytes from persistently lymphocytotic cows to human recombinant cytokines and to cytokine-containing supernatants from isolated T lymphocytes was examined. While recombinant human IL-10 (rhIL-10) did not consistently induce detectable changes, rhIL-2 increased viral protein (p24) and IL-2 receptor expression in isolated B lymphocytes from persistently lymphocytotic cows. Additionally, rhIL-2 and supernatant from ConA-stimulated T lymphocytes enhanced B-lymphocyte proliferation. The stimulatory activity of the T-lymphocyte supernatant could be completely inhibited with a polyclonal anti-rhIL-2 antibody. Finally, polyclonal anti-rhIL-2 antibody, as well as anti-BLV antibody, inhibited spontaneous proliferation of peripheral blood mononuclear cells from persistently lymphocytotic cows, demonstrating that the spontaneous lymphoproliferation characteristic of BLV-induced persistent lymphocytosis is IL-2 dependent and antigen dependent. Collectively, these findings strongly suggest that increased T-lymphocyte expression of IL-2 in BLV-infected cows contributes to development and/or maintenance of persistent B lymphocytosis.
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Affiliation(s)
- E S Trueblood
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164, USA.
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Orlik O, Splitter GA. Optimization of lymphocyte proliferation assay for cells with high spontaneous proliferation in vitro: CD4+ T cell proliferation in bovine leukemia virus infected animals with persistent lymphocytosis. J Immunol Methods 1996; 199:159-65. [PMID: 8982358 DOI: 10.1016/s0022-1759(96)00178-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Evaluation of antigen specific lymphocyte proliferation is extremely difficult with cells displaying high spontaneous proliferation in vitro, such as bovine leukemia virus (BLV) and T cell leukemia virus type I (HTLV-I) infected cells. We introduced modifications to a standard proliferation protocol, and for the first time report antigen specific proliferation in BLV infected animals with persistent lymphocytosis (a benign proliferation of B lymphocytes). Serum (autologous, heterologous or fetal) but not medium was a major factor contributing to spontaneous proliferation. Spontaneous proliferation was strongly serum concentration dependent and reducing serum to 0.5-1% resulted in decreased background proliferation and development of a functional assay. Addition of indomethacin (3-6 micrograms/ml) further increased antigen specific responses not only from persistently lymphocytotic but also from lymphosarcoma animals. Thus, this modified proliferation protocol can be used in infections where background proliferation hinders evaluation of antigen-specific CD4+ T cells.
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Affiliation(s)
- O Orlik
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706, USA
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Jensen WA, Wicks-Beard BJ, Cockerell GL. Inhibition of protein kinase C results in decreased expression of bovine leukemia virus. J Virol 1992; 66:4427-33. [PMID: 1318412 PMCID: PMC241250 DOI: 10.1128/jvi.66.7.4427-4433.1992] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The in vitro expression of bovine leukemia virus (BLV) in short-term cultured bovine peripheral blood mononuclear cells (PBMC) is associated with increased spontaneous lymphocyte blastogenesis. The purpose of this study was to determine whether intracellular pathways responsible for antigen- or mitogen-induced lymphocyte blastogenesis were also responsible for induction of BLV expression. The protein kinase C (PKC) inhibitor 1-(5-isoquinolinylsulfonyl)-3-methylpiperazine dihydrochloride (3-methyl H7) decreased blastogenesis in a dose-dependent manner, as measured by [3H]thymidine incorporation, in unstimulated, lipopolysaccharide-stimulated and phorbol ester (PMA)-stimulated BLV-infected PBMC. Similarly, 3-methyl H7 decreased BLV expression, as measured by production of gp51 envelope antigen or p24gag antigen, in BLV-infected PBMC under the same conditions. Using an RNase protection assay, the inhibition of BLV expression by 3-methyl H7 was shown to be due to decreased transcriptional activity. The cyclic GMP-dependent protein kinase and cyclic AMP-dependent protein kinase inhibitor N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA1004) did not inhibit either BLV expression or blastogenesis of BLV-infected bovine PBMC. Additional evidence for the PKC-dependent expression of BLV was obtained by using a persistently BLV-infected B-lymphocyte cell line, NBC-13. Activation of PKC by PMA in NBC-13 cells increased BLV expression. 3-methyl H7 decreased the PMA-induced expression of BLV in NBC-13 cells in a dose-dependent manner, whereas HA1004 did not inhibit this expression. These results identify a mechanism for the induction of BLV expression through PKC activation and therefore indicate that latency and replication of BLV is controlled by normal B-lymphocyte intracellular signaling pathways.
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Affiliation(s)
- W A Jensen
- Department of Pathology, Colorado State University, Fort Collins 80523
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Koyama H, Hohdatsu T, Nagai T, Tsubaki S. Determination of lymphocyte count necessary for isolating bovine leukaemia virus (BLV) from BLV-infected cattle and correlation between lymphocyte count and antibody titre. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1988; 35:648-53. [PMID: 2849842 DOI: 10.1111/j.1439-0450.1988.tb00540.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Burny A, Cleuter Y, Kettmann R, Mammerickx M, Marbaix G, Portetelle D, van den Broeke A, Willems L, Thomas R. Bovine leukaemia: facts and hypotheses derived from the study of an infectious cancer. Vet Microbiol 1988; 17:197-218. [PMID: 2847391 DOI: 10.1016/0378-1135(88)90066-1] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bovine leukaemia virus (BLV) is the etiological agent of chronic lymphatic leukaemia/lymphoma in cows, sheep and goats. Infection without neoplastic transformation was also obtained in pigs, rhesus monkeys, chimpanzees, rabbits and observed in capybaras and water-buffaloes. Structurally and functionally, BLV is a relative of human T lymphotropic viruses 1 and 2 (HTLV-I and HTLV-II) In humans, HTLV-I induces a T-cell leukaemia and its type 2 counterpart has been found in dermatopathic lymphadenopathy, hairy T-cell leukaemia and prolymphocytic leukaemia cases. At variance with HTLV-I, BLV has not been associated with neurological diseases of the degenerative type. Bovine leukaemia virus, HTLV-I and HTLV-II show clearcut sequence homologies. The pathology of the BLV-induced disease, most notably the absence of chronic viraemia, a long latency period and lack of preferred proviral integration sites in tumours, is similar to that of adult T-cell leukaemia/lymphoma induced by HTLV-I. The most striking feature of these three naturally transmitted leukaemia viruses is the X region located between the env gene and the long terminal repeat (LTR) sequence. The X region contains several overlapping long open reading frames. One of them, designated XBL-I, encodes a trans-activator function capable of increasing the level of gene expression directed by BLV-LTR and most probably is involved in "genetic instability" of BLV-infected cells of the B cell lineage. The "genetic instability" renders the infected cell susceptible to move, along a number of stages, towards full malignancy. Little is known about these events and their causes; we present some theoretical possibilities. Bovine leukaemia virus infection has a worldwide distribution. In temperate climates, the virus spreads mostly via iatrogenic transfer of infected lymphocytes. In warm climates and in areas heavily populated by haematophagous insects, there are indications of insect-borne propagation of the virus.
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Affiliation(s)
- A Burny
- Faculty of Agronomy, Gembloux, Belgium
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Burny A, Cleuter Y, Kettmann R, Mammerickx M, Marbaix G, Portetelle D, Van den Broeke A, Willems L, Thomas R. Bovine leukemia: facts and hypotheses derived from the study of an infectious cancer. ADVANCES IN VETERINARY SCIENCE AND COMPARATIVE MEDICINE 1988; 32:149-70. [PMID: 2847501 DOI: 10.1016/b978-0-12-039232-2.50010-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bovine leukemia virus is the etiological agent of a chronic lymphatic leukemia/lymphoma in cows, sheep, and goats. Infection without neoplastic transformation also was obtained in pigs, rhesus monkeys, chimpanzees, and rabbits, and was observed in capybaras and water buffaloes. Structurally and functionally, BLV is a relative of the human T lymphotropic viruses (HTLV-I and HTLV-II). HTLV-I induces in humans a T cell leukemia, and its type II counterpart has been found in dermatopathic lymphadenopathy, hairy T cell leukemia and prolymphocytic leukemia cases. At variance with HTLV-I, BLV has not been associated with neurological diseases of the degenerative type. BLV, HTLV-I, and HTLV-II show clearcut sequence homologies. The pathology of the BLV-induced disease, most notably, the absence of chronic viremia, a long latency period, and a lack of preferred proviral integration sites in tumors, is similar to that of adult T cell leukemia/lymphoma induced by HTLV-I. The most striking feature of the three naturally transmitted leukemia viruses is the X region located between the env gene and the LTR sequence. The X region contains several overlapping long open reading frames. One of them designated XBL-I encodes a trans-activator function capable of increasing the level of gene expression directed by BLV-LTR and most probably involved in "genetic instability" of BLV-infected cells of the B cell lineage. The genetic instability puts the cell into a context of fragility and ready to move along a number of stages towards full malignancy. Little is known about these events and their causes; we have presented some theoretical possibilities. BLV infection has a worldwide distribution. In temperate climates the virus spreads mostly via iatrogenic transfer of infected lymphocytes. In warm climates and in areas heavily populated by hematophageous insects, there are indications of insect-born propagation of the virus.
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Affiliation(s)
- A Burny
- Faculty of Agronomy, Gembloux, Belgium
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Koyama H, Ide T, Yoshikawa H, Okada K, Yoshikawa T, Saito H. Frequency of lymphocytes bearing surface membrane immunoglobulins in leukaemic cattle. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1987; 34:371-9. [PMID: 2825451 DOI: 10.1111/j.1439-0450.1987.tb00410.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Pathology of Enzootic Bovine Leukosis. Comparison with the Sporadic Form. ENZOOTIC BOVINE LEUKOSIS AND BOVINE LEUKEMIA VIRUS 1987. [DOI: 10.1007/978-1-4613-2341-9_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Cockerell GL, Parodi AL, Levy D. Immunocompetence of sheep experimentally infected with bovine leukemia virus. Vet Immunol Immunopathol 1986; 13:189-202. [PMID: 3026080 DOI: 10.1016/0165-2427(86)90072-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The humoral and cellular immunological reactivity of sheep were studied throughout the first 32 weeks following experimental infection with bovine leukemia virus (BLV). Seroconversion of BLV-inoculated sheep occurred within 4 weeks, but infection was not transmitted to contact control sheep. Despite the persistence of the viral infection, no differences were demonstrated in leukograms, serum IgG concentrations, humoral response to immunization with an irrelevant antigen (rabbit red blood cells), phytomitogen (Concanavalin A and Pokeweek mitogen)-induced lymphocyte blastogenesis, or chemical (1-chloro, 2-4 dinitrobenzene) skin contact hypersensitivity, between BLV-infected and uninfected contact control sheep. These results demonstrate the absence of a nonspecific immunosuppressive effect of BLV and further negate the influence of a generalized immunological deficit on the development of clinical disease in BLV-infected animals.
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Lewin HA, Bernoco D. Evidence for BoLA-linked resistance and susceptibility to subclinical progression of bovine leukaemia virus infection. Anim Genet 1986; 17:197-207. [PMID: 3490197 DOI: 10.1111/j.1365-2052.1986.tb03191.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The role of the bovine major histocompatibility complex in bovine leukaemia virus (BLV) infection and disease progression was investigated in a herd of Shorthorn cattle (n = 117). The frequency of cows that were seropositive to BLV-glycoprotein antigen was 51%. Twenty-three per cent of the seropositive cows were lymphocytotic. At the herd level, relative resistance to BLV-dependent B-cell proliferation and lymphocytosis among seropositive cows was associated with bovine lymphocyte antigen (BoLA)-DA7, whereas susceptibility was associated with BoLA-DA12.3. These associations were also confirmed at the family level, where BoLA phenotypes were used as haplotypic markers. Among the offspring of one BoLA-heterozygous sire (n = 33), resistance segregated with the DA7 haplotype and susceptibility with the DA12.3 haplotype. In this sire group, maternal transmission of the BoLA-w8 allele was associated with increased susceptibility to B-cell proliferation and lymphocytosis in w8/DA12.3 heterozygotes. These data provide the first evidence that subclinical progression of BLV infection is under the control of the BoLA complex, and suggest that the BoLA system can be used to select for resistance to B-cell proliferation and the development of lymphocytosis in BLV-infected herds.
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Phytohemagglutinin activation of the transcription of the bovine leukemia virus genome requires de novo protein synthesis. J Virol 1985; 54:860-3. [PMID: 2987537 PMCID: PMC254875 DOI: 10.1128/jvi.54.3.860-863.1985] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Addition of supramitogenic doses of phytohemagglutinin (PHA) to short-term cultures of neoplastic or nonneoplastic lymphocytes infected with bovine leukemia virus increased the synthesis of the major core virion antigen (p25) by 5- to 10-fold. Such stimulation was not due to the mitogenic effect of PHA or to a generalized increase in cellular RNA or protein synthesis but rather to enhanced transcription of the viral genome by a PHA-induced protein.
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Abstract
The bovine leukemia virus mRNAs expressed in cultured bovine cells of various origins are a 9.0-kilobase genomic RNA, a 5.1-kilobase env RNA, and a newly detected 2.1-kilobase RNA corresponding to the transcription of pX sequences located in between the env gene and the 3' end of the provirus.
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Buxton BA, Schultz RD. Factors affecting the infectivity of lymphocytes from cattle with bovine leukosis virus. CANADIAN JOURNAL OF COMPARATIVE MEDICINE : REVUE CANADIENNE DE MEDECINE COMPAREE 1984; 48:365-9. [PMID: 6095977 PMCID: PMC1236085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Peripheral blood mononuclear cells were obtained from 13 bovine leukosis virus infected cattle and inoculated subcutaneously into 29 recipient adult steers to determine (a) the number of mononuclear cells (equivalent amount of blood) necessary to cause infection and (b) factors influencing infectivity of mononuclear cells from bovine leukosis virus-infected animals. A total of 55 inoculations were made. Inoculation of 1 X 10(4), 2 X 10(4) and 5 X 10(4) mononuclear cells caused seroconversion in 12%, 57% and 62% of steers, respectively. No infections occurred with 1 X 10(3) or 2 X 10(3) mononuclear cells. Cattle infected for longer than 24 months and those animals greater than three years of age were more likely to cause infection with 1 to 5 X 10(4) mononuclear cells than were cattle infected for less than 24 months or animals less than three years of age. Lymphocytes from cattle with persistent lymphocytosis caused more infections when 1 X 10(4) or 2 X 10(4) mononuclear cells were inoculated, than did lymphocytes from nonpersistent lymphocytosis cattle; however, both groups were equally infectious when 5 X 10(4) mononuclear cells were inoculated. No differences were found in infectivity of experimentally vs naturally exposed animals.
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Bruck C, Portetelle D, Mammerickx M, Mathot S, Burny A. Epitopes of bovine leukemia virus glycoprotein gp51 recognized by sera of infected cattle and sheep. Leuk Res 1984; 8:315-21. [PMID: 6205222 DOI: 10.1016/0145-2126(84)90070-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Sera of BLV-infected cattle and sheep are tested for their reactivity with different gp51 subregions by competition with radiolabeled monoclonal antibodies directed against 8 different gp51 epitopes. Sheep antisera are found to be very polyvalent, since they are able to displace the fixation of any of the mouse monoclonal antibodies to gp51. Bovine antisera do not display significant competition with monoclonal antibodies direct against 5 out of 8 gp51 epitopes. The bovine antibody response to gp51 is focused to a limited subregion of this molecule, bearing 3 epitopes (F, G and H) recognized by antibodies with virus-neutralizing activity. The differential reactivity of cattle and sheep antisera to BLV gp51 is discussed in relation to the pathology of BLV infection in these two species.
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Van der Maaten MJ, Schmerr MJ, Miller JM, Sacks JM. Levamisole does not affect the virological and serological responses of bovine leukemia virus-infected cattle and sheep. CANADIAN JOURNAL OF COMPARATIVE MEDICINE : REVUE CANADIENNE DE MEDECINE COMPAREE 1983; 47:474-9. [PMID: 6321003 PMCID: PMC1235979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Levamisole, a compound that has been used widely as an anthelmintic in man and domestic animals, has also been found to be an immunomodulator. It was, thus, of interest to determine whether treatment with levamisole would affect bovine leukemia virus infections in cattle and sheep or the results of serological and virological tests routinely used to identify infected animals. Studies of cattle and sheep given either the recommended anthelmintic dose of levamisole or repeated larger doses of the drug failed to provide evidence of significant changes in antibody titer or virus replication. It is, therefore, concluded that levamisole neither potentiated nor repressed bovine leukemia virus replication or the associated immunological responses.
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Miller JM, van der Maaten MJ. Bovine leukosis--its importance to the dairy industry in the United States. J Dairy Sci 1982; 65:2194-203. [PMID: 6296209 DOI: 10.3168/jds.s0022-0302(82)82482-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bovine leukosis describes lymphatic cancers of cattle. The most common form of this disease occurs in adult animals and is caused by bovine leukemia virus. Infection is widespread in the United States, especially in dairy cattle, but the virus produces tumors in only a small percentage of infected animals. Nevertheless, bovine leukemia virus has been receiving attention from the dairy industry because of its importance in health certification of cattle or semen intended for export. Another source of concern is whether bovine leukemia virus poses any risk to human health. These problems are discussed in the light of recent technological advances in tumor virus research and specifically regarding our current understanding of the biology of bovine leukemia virus.
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Mayr B, Vogel I, Graninger W, Schlerka G, Wöckl F, Schleger W. Circulating immune cells and immune complexes in peripheral blood of healthy and of bovine leukemia virus-infected cows and lymphosarcomatous calves. Vet Immunol Immunopathol 1982; 3:475-84. [PMID: 6897311 DOI: 10.1016/0165-2427(82)90013-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The peripheral blood (lymphocytes and immune complexes (IC) from 20 healthy cows, 5 healthy calves, 10 bovine leukemia virus-infected cows and 4 lymphosarcomatous calves was investigated using 4 different immunological techniques. A highly significant increase in the percentage of surface immunoglobulin (SIg)-bearing peripheral blood lymphocytes of persistent lymphocytosis-cows could be demonstrated while the percentage was decreased in the lymphosarcomatous calves. Percentages of spontaneous sheep red blood cells(SRBC)-rosettes (E-rosettes) were not elevated. Antibodies to bovine leukemia virus-antigen were detected in the sera (immuno-diffusion test) of all the leukotic cows but not of the lymphosarcomatous calves. Although there seems to be an increased level of IC in the advanced stage, as compared to the beginning of the disease, there was no statistically significant difference in comparison with the control individuals. In the lymphosarcomatous calves as well as in the leukemic cows there was no statistical difference in the IC values between diseased animals and controls.
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Thorn RM, Gupta P, Kenyon SJ, Ferrer JF. Evidence that the spontaneous blastogenesis of lymphocytes from bovine leukemia virus-infected cattle is viral antigen specific. Infect Immun 1981; 34:84-9. [PMID: 6271688 PMCID: PMC350824 DOI: 10.1128/iai.34.1.84-89.1981] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cattle lymphocytes cultured for 3 days were found to spontaneously incorporate thymidine (3STI). Under optimal conditions of culture, the median magnitude of 3STI activity in lymphocytes from bovine leukemia virus (BLV)-infected cattle was higher than that of BLV-free cattle, but the ranges of the values overlapped. However, the 3STI activity of most BLV-infected cattle was specifically inhibited by serum containing BLV antibodies, whereas the 3STI activity of BLV-free cattle was not. The 3STI inhibitor copurified with immunoglobulin, and its activity could be absorbed with BLV. Rabbit anti-BLV serum inhibited 3STI, but rabbit anti-BLV p25 did not. These results indicate that BLV infection induces or expands a BLV-specific lymphocyte population. Spontaneous blastogenesis may be indicative of an immune response which controls virus spread.
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Abstract
The cell cycle of fetal lamb kidney (FLK) cultures chronically infected with bovine leukosis virus was synchronized by double thymidine block. The synchronized FLK cells were examined by production of BLV antigen and virion release by cytoplasmic immunofluorescence and syncytia forming assay, respectively. The production of BLV antigens was increased during S and G2 phases and was decreased during M and G1 phases. BLV release was associated with the M phase of FLK cells. Short term lymphocyte cultures from BLV infected cattle were treated with hydroxyurea and mitomycin C. The expression of BLV antigen and DNA synthesis of PHA stimulated lymphocytes was inhibited by both drugs.
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Takashima I, Olson C. Effect of mitogens and anti-bovine leukosis virus serums on DNA synthesis of lymphocytes from cattle. Eur J Cancer 1980; 16:639-45. [PMID: 6248346 DOI: 10.1016/0014-2964(80)90204-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Kettmann R, Cleuter Y, Mammerickx M, Meunier-Rotival M, Bernardi G, Burny A, Chantrenne H. Genomic integration of bovine leukemia provirus: comparison of persistent lymphocytosis with lymph node tumor form of enzootic. Proc Natl Acad Sci U S A 1980; 77:2577-81. [PMID: 6248854 PMCID: PMC349445 DOI: 10.1073/pnas.77.5.2577] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Integration of bovine leukemia proviral DNA in the genome of infected cells was investigated in cattle affected by either the persistent lymphocytosis or the lymph node tumor form of enzootic bovine leukosis. In persistent lymphocytosis, proviral DNA was found to be integrated at a large number of genomic sites in one-fourth to one-third of circulating leukocytes. In the lymph node tumor form, in contrast, proviral DNA was found to be integrated at one or very few sites in the genomes of a larger fraction of both circulating leukocytes and lymph node tumor cells.
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Kettmann R, Marbaix G, Cleuter Y, Portetelle D, Mammerickx M, Burny A. Genomic integration of bovine leukemia provirus and lack of viral RNA expression in the target cells of cattle with different responses to BLV infection. Leuk Res 1980; 4:509-19. [PMID: 6259449 DOI: 10.1016/0145-2126(80)90062-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Diglio CA, Piper CE, Ferrer JF. An improved syncytia infectivity assay for the bovine leukemia virus. IN VITRO 1978; 14:502-5. [PMID: 210107 DOI: 10.1007/bf02616090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several factors that influence the sensitivity of the syncytia infectivity assay for the bovine leukemia virus (BLV) and BLV-infected lymphocytes have been examined. The use of early-passage indicator bovine embryonic spleen (BESP) cells and their pretreatment with diethylamino-ethyl-dextran (DEAE-D) was essential for optimal sensitivity. Polybrene was less effective than DEAE-D. The combination of DEAE-D and polybrene was more effective than DEAE-D alone when BLV-infected leukocytes were used as the inoculum, but not when the inoculum was a cell-free BLV preparation. Using BESP cell passages 4 to 11 as indicators, reproducible titers were obtained when aliquots of the same virus stock were assayed at different times after freezer storage. When assaying peripheral blood lymphocytes from infected cattle, optimal syncytia responses were observed consistently by inoculating 5 X 10(6) viable lymphocytes per 60-mm Falcon dish. Centrifugation of peripheral blood leukocytes from BLV-infected cattle in discontinuous bovine serum albumin gradients can be used to separate a subpopulation of infected lymphocytes. Use of this subpopulation as the inoculum, rather than unseparated buffy-coat leukocytes, greatly increases the sensitivity of the syncytia infectivity assay.
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Kenyon SJ, Piper CE. Cellular basis of persistent lymphocytosis in cattle infected with bovine leukemia virus. Infect Immun 1977; 16:891-7. [PMID: 197011 PMCID: PMC421046 DOI: 10.1128/iai.16.3.891-897.1977] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Peripheral blood lymphocytes from 14 cattle infected with the bovine leukemia virus (BLV) and 14 BLV-free cattle were examined by the membrane immunofluorescent antibody technique to detect surface immunoglobulin (S-Ig) and by the erythrocyte-antibody-complement (EAC) rosette test for the detection of complement receptors. Direct comparisons of the percentages of S-Ig-bearing cells and EAC rosette-forming cells in both infected and BLV-free animals showed no evidence for the presence of a substantial population bearing one surface marker but not the other. The data showed that cells with surface markers characteristic of B lymphocytes are responsible for most of the increase in peripheral blood lymphocytes which may accompany BLV infection. The release of infectious BLV and the spontaneous uptake of thymidine by short-term cultured peripheral blood lymphocytes from BLV-infected cattle were also studied. The results indicate that both of these activities are function of B lymphocytes.
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