Date of Award

1986

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Abstract

Highly specific monoclonal antibodies and microfluorimetry were used to determine the absolute number of B and T lymphocytes in the peripheral blood of bovine leukemia virus (BLV) infected cattle. The peripheral blood lymphocyte populations from BLV-infected cattle were elevated when compared to BLV-negative animals. The increase in the lymphocyte population in the aleukemic (AL) animals was due to an increase in T lymphocytes. In the PL animals the increase was due mainly to an increase of B lymphocytes but also to an increase of T lymphocytes. The PL animals showed a significantly higher number of surface immunoglobulin positive cells (sIg('+)) than did the AL animals. The majority of these cells contained surface IgM and had large quantities of this marker on their cell surfaces. One PL animal (632) had a very high lymphocyte court and contained lymphocytes that appeared to stain with markers for both bovine B and T lymphocytes. Bovine T lymphocytes were purified from the peripheral blood of BLV-infected, AL cattle using immuno-affinity depletion technique ("panning") with anti-bovine immunoglobulin-coated flasks. Large yields of highly purified T lymphocyte preparations (95-100% T lymphocytes and 0-3% contamination with B lymphocytes) were obtained by the use of this technique. The BLV provirus was found in the DNA of peripheral blood lymphocytes and 3 of 4 purified T lymphocyte preparations from AL animals using hybridization analysis with radiolabeled BLV-DNA as a probe. Hybridization analysis also confirmed that the B lymphocyte is the major target of BLV infection. The blastogenic response of lymphocytes from PL and AL animals to selected phytomitogens appeared to be normal when compared to the responses of BLV-negative, clinically normal animals. The sera from both AL and PL animals contained a heat-stable, comitogenic blastogenesis-augmenting factor.

Pages

163

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