Augmentation of Bovine Leukemia Virus (BLV)-Specific Lymphocyte Proliferation Responses in Ruminants by Inoculation with BLVenv-Recombinant Vaccinia Virus: Their Role in the Suppression of BLV Replication

Delayed-type hypersensitivity responses against bovine leukemia virus (BLV) envelope glycoprotein (gp60) were induced in the skin of sheep vaccinated with recombinant vaccinia virus (RVV) expressing BLV glycoprotein. The lesions were characterized by marked infiltration of lymphocytes, slight migration of neutrophils, eosinophils, and macrophages in the dermis to hypodermis, and partial intercellular edema in the reticular layer. Immunohistochemical analysis with monoclonal antibodies demonstrated that the lymphocytic infiltrates consisted mainly of CD8+ T cells (53.7–55.8% at 48 hours post-challenge of BLV), CD4+ T cells (24.7–26.7%), and B cells (11.5–16.9%). The role of CD4+ and CD8+ T cells in suppressing BLV growth in RVV-vaccinated animals is discussed.

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Expression of the bovine leukemia virus transactivator protein p34 by a recombinant vaccinia virus

Veterinary Immunology and Immunopathology ◽

10.1016/0165-2427(89)90007-x ◽

1989 ◽

Vol 22 (3) ◽

pp. 201-211

Author(s):

L. Willems ◽

C. Letellier ◽

M. Gonze ◽

R. Martin ◽

R. Kettmann ◽

...

Keyword(s):

Vaccinia Virus ◽

Bovine Leukemia Virus ◽

Leukemia Virus ◽

Recombinant Vaccinia Virus ◽

Recombinant Vaccinia ◽

Transactivator Protein

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FBL-reactive CD8+ cytotoxic and CD4+ helper T lymphocytes recognize distinct Friend murine leukemia virus-encoded antigens.

Journal of Experimental Medicine ◽

10.1084/jem.169.2.457 ◽

1989 ◽

Vol 169 (2) ◽

pp. 457-467 ◽

Cited By ~ 43

Author(s):

J P Klarnet ◽

D E Kern ◽

K Okuno ◽

C Holt ◽

F Lilly ◽

...

Keyword(s):

T Cell ◽

Vaccinia Virus ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Recombinant Vaccinia Virus ◽

Tumor Rejection ◽

Target Cells ◽

Gene Products ◽

Recombinant Vaccinia ◽

Murine Leukemia

Immunization of C57BL/6 (B6) mice with FBL, a Friend murine leukemia virus (F-MuLV), induces both tumor-specific cytolytic CD8+ (CTL) and lymphokine-producing CD4+ Th that are effective in adoptive therapy of B6 mice bearing disseminated FBL leukemia. The current study evaluated the F-MuLV antigenic determinants expressed on FBL that are recognized by FBL-reactive CD8+ and CD4+ T cells. To identify the specificity of the FBL-reactive CD8+ CTL, Fisher rat embryo fibroblast (FRE) cells transfected with plasmids encoding F-MuLV gag or envelope (env) gene products plus the class I-restricting element Db were utilized. FBL-reactive CTL recognized FRE target cells transfected with the F-MuLV gag-encoded gene products, but failed to recognize targets expressing F-MuLV env. Attempts to generate env-specific CD8+ CTL by immunization with a recombinant vaccinia virus containing an inserted F-MuLV env gene were unsuccessful, despite the generation of a cytolytic response to vaccinia epitopes, implying that B6 mice fail to generate CD8+ CTL to env determinants. By contrast, CD4+ Th clones recognized FRE target cells transfected with env and not gag genes, and immunization with the recombinant vaccinia virus induced an env-specific CD4+ T cell response. These data show that in a Friend retrovirus-induced tumor model in which tumor rejection can be mediated by either CTL or Th, antigens derived from discrete retroviral proteins are predominantly responsible for activation of each T cell subset.

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