Frequency of Lymphocytes bearing surface Membrane Immunoglobulins in Leukaemic Cattle

Abstract

Summary The percentages of surface immunoglobuline‐positive (SIg+) cells in peripheral blood lymphocyte (PBL) and lymph nodes of 20 normal cattle were compared with those in the PBL, tumourous lymph nodes and tumour tissues of 33 cases of enzootic bovine leukosis (EBL). EBL animals were classified into three groups: one showing high SIg+ cell percentages in the lymphoid organs (SIgH group), one with low percentages (SIgL group) and one with intermediate values (SIgM group). Most of the EBL animals belonged to either the SIgH or the SIgL group. The number of such animals was 13:13 for PBL, 12:14 for the tumourous lymph nodes and 14:19 for tumour tissues. The number of SIgM animals was very small. Most of the animals with SIgH or SIgL tumour tissue were classified into the same SIg group for the lymphoid organs. The SIg+ cell percentages in all the specimens were low in the SIgL group: 13.2 ± 9.1% and 6.5 ± 6.0%, respectively, in the tumour tissue, as determined by antibovine Ig and IgG sera. Of the 31 EBL animals, 21 exhibited persistent lymphocytosis. Nine of these 21 were in the SIgH group, and 11, in the SIgL group, with no special bias found. These results indicate that the tumours were composed of surface immunoglobulin‐negative cells in some EBL animals. Zusammenfassung Häufigkeit von Lymphocyten mit Oberflächenmembran‐Immunglobulinen bei leukämischen Rindern Der prozentuale Anteil Oberflächen‐Immunglobulin positiver (SIg+) Zellen an peripheren Blutlymphocyten (PBL) und Lymphknoten von 20 normalen Rindern wurde mit dem an PBL, tumorösen Lymphknoten und Tumorgewebe von 33 Fällen enzootischer boviner Leukose (EBL) verglichen. Die EBL‐Tiere wurden in drei Gruppen eingeteilt: eine mit hoher Prozentzahl SIg+‐Zellen in den lymphoiden Organen (SIgH‐Gruppe), eine mit niedriger Prozentzahl (SIgL‐Gruppe) und eine mit mittleren Werten (SIgM‐Gruppe). Die meisten der EBL‐Tiere gehörten entweder zur SIgH‐ oder zur SIgL‐Gruppe. Die Anzahl dieser Tiere betrug 13:13 für PBL, 12:14 für tumoröse Lymphknoten und 14:19 für Tumorgewebe. Die Anzahl von SIgM‐Tieren war sehr gering. Die meisten Tiere mit SIgH‐ oder SIgL‐Tumorgewebe gehörten bezüglich lymphoider Organe in die gleiche SIg‐Gruppe. Der prozentuale Anteil von SIg+‐Zellen in Tumorgeweben aller Tiere der SIgL‐Gruppe, der mittels Antiseren gegen bovines Ig und IgG bestimmt wurde, betrug nur 13,2 ± 9,1% bzw. 6,5 ± 6,0%. Von den 33 EBL‐Tieren wiesen 21 eine persistierende Lymphocytose auf. Von diesen 21 Tieren gehörten 9 zur SIgH‐ und 11 zur SIgL‐Gruppe. Diese Ergebnisse weisen darauf hin, daß die Tumoren bei einigen EBL‐Tieren aus Oberflächen‐Immunglobulin negativen Zellen gebildet wurden.

Properties of Nine Continuous B‐Cell Lines Established from Enzootic Bovine Leukosis Tumors

“…These results suggest that there is no correlation between the percentage of SIgpositive PBL and that of SIg-positive established line cells. One study showed that some EBL cattle lose part of their B-lymphocyte SIg (7,10,13). The SIg-negative line cells observed in the present study are also considered to have lost Slg.…”

“…We recently reported that tumor cells in many EBL cattle are SIg-negative or that the percentage of SIg-positive cells is very low (7). The percentages of SIg-positive PBL in cows 969 and 972 were respectively 42.6 YO and 40.3 %.…”

“…Sixty-three cattle with typical EBL, which had been confirmed clinically and histologically, were used. Peripheral blood lymphocytes (PBL) of each animal were obtained from the heparinized blood by the Ficoll-Conray technique (7). It was cytologically demonstrated that the PBL contained tumor cells.…”

“…They were positive for SIg. O n the other hand, our recent study showed that the number of tumors composed of SIg-negative cells was more frequent than that composed of Slg-positive cells (7). These SIg-negative tumor cells reacted with the monoclonal antibody (MoAb; recognizing B-cells that we prepared (9).…”

Lymphosarcoma Development in Sheep Experimentally Infected with Bovine Leukaemia Virus

“…Enzootic bovine leukosis (EBL) is a chronic lymphoproliferative neoplastic disease of cattle due to infection with bovine leukemia virus (BLV) (MILLER et al, 1969, 1972). BLV is an RNA oncogenic retrovirus and exogenous to BLV infects B lymphocytes (PAUL et al, 1977;KETTMANN et al, 1980) and is associated with an asymptomatic elevation of a cell population bearing B lymphocyte markers in cattle with PL (KUMAR et al, 1978;PAUL et al, 1979;KOYAMA et al, 1983;ESTEBAN et al, 1985;FOSSUM et al, 1988) or with lymphosarcoma (KOYAMA et al, 1987) and in sheep experimentally infected with BLV (TAKASHIMA and OLSON, 1980;DJILALI et al, 1987a). It has been shown that BLV proviral D N A is integrated in many different sites in the cellular DNA of cattle with PL (KETTMANN et al, 1980) but in a more restricted fashion in BLV infected sheep (KETTMANN et al, 1984;LADD et al, 1988).…”