B-Lymphocytes and T-Lymphocytes in Three Types of Bovine Lymphosarcoma 2

Abstract

Lymphoid cells of peripheral blood, lymph nodes, and thymus from clinically normal cattle, cattle infected with bovine leukemia virus (BLV), and cattle with lymphosarcoma were characterized for T- and B-cell surface markers. B-cells were detected by the erythrocyte-antibody-complement (EAC) rosette test and the surface immunoglobulin (sig) immunofluorescence assay. Peripheral blood from BLV-infected cattle had a higher than normal percentage of B-cells by both EAC rosette and sig immunofluorescence assays. Lymphoid cells from tumorous lymph nodes of cattle with the adult type of lymphosarcoma had a higher than normal percentage of sig-bearing cells, but in the same cell preparation the EAC rosette-positive cells were fewer than sig-positive cells. T-cells were detected by the erythrocyte rosette test. The percentage of T-cells by this test in lymph nodes of adult type lymphosarcoma was lower than that in normal cattle. A distinctly lower than normal percentage of lymphocytes could be characterized as either B- or T-cells in lymph nodes thymus, and peripheral blood from the calf type and thymic type of lymphosarcoma.

Relation between Phenotype of Tumor Cells and Clinicopathology in Bovine Leukosis

“…But the gene c-myb is found in tumor cells of SBL [1]. SBL consists of tumor cells bearing the character of either T or B cell which exhibits monoclonal proliferation [2,15,31].…”

Cytochemical Reactions in Bovine and Ovine Lymphosarcoma

“…Only one thymic bovine lymphosarcoma was available for study with cytochemical stains. No surface immunoglobulin positive cells were found in the thymus; previous studies have shown 0 to 10% E-rosette positive cells in the peripheral blood and thymus of two animals [17]. The tumor cells were small to medium lymphocytes with relatively sparse cytoplasm, at times showing a "hand-mirror'' appearance which has been observed in some human acute lymphocytic leukemias.…”

“…No similar studies have been reported in bovine and ovine lymphosarcoma. In previous studies findings have been reported of B and T cell typing in three types of bovine lymphosarcoma [17] and surfaceimmunoglobulin-bearing cells in sheep infected with bovine leukosis virus [ 161. This report expands these observations to include cytochemical reactions in three of the four types of bovine lymphosarcoma and in ovine lymphosarcoma induced with bovine leukosis virus.…”

Flow Cytometric Determination of the Expression of gp 51 Protein of Bovine Leukaemia Virus in Experimentally Infected Sheep

“…Tumours develop as an effect of clonal outgrowths of a single BLV-infected cell containing one to several copies of the provirus integrated into host cell DNA (19). Integration sites vary in tumours from different animals, which indicates that the virus does not transform cells by insertional activation of a host gene (32,36). Tumours may contain full-length provirus, but some harbour incomplete proviruses retaining the 3' tax/rex region of the genome (2).…”

“…Tumourigenesis is initiated when the BLV Tax protein alters host cell gene expression (15,31). Alteration in cellular gene expression appears to render infected cells susceptible to mutations in host genes (19,32). Last year, a new genotype of BLV was identified and this additional information can be very useful in explication of infection mechanism (4).…”