Document 0073
 DOCN  M9440073
 TI    Effects of experimental feline leukemia virus infection on peripheral
       lymphocyte subsets.
 DT    9404
 AU    Nelson PD; North Carolina State Univ. at Raleigh
 SO    Diss Abstr Int [B]; 54(5):2394 1993. Unique Identifier : AIDSLINE
       ICDB/94698747
 AB    Feline leukemia virus (FeLV) is a retrovirus of cats that commonly
       causes immunosuppression and neoplasia of various cellular origins.
       FeLV-infected cats generally exhibit clinical symptoms of chronic
       infections, and reduced cell-mediated responses to antigen challenges,
       similar to humans infected with human immunodeficiency virus (HIV). To
       determine if FeLV induces changes in peripheral blood lymphocyte subset
       numbers similar to those present in HIV patients, two groups of cats
       (FeLVR, FeLVR2) were experimentally infected with the Rickard strain of
       FeLV (FeLV(R).) Lymphocyte subset changes in infected cats included a
       pan-lymphopenia during the first 2 wk of infection, followed by a 10-wk
       delay in peak numbers of T-lymphocytes (CD4+ and CD8+ subsets) when
       compared to controls. One experimental group (FeLVR2) never attained
       control peak levels of T lymphocytes, and exhibited a significantly
       shorter median survival time. In one group of experimentally infected
       cats, a non-neutralizing B-lymphocytic response was evidenced by
       significantly higher B-cell numbers during the subacute-chronic stages
       of infection (10-30 wk pi) without development of protective FOCMA
       titers. Both groups exhibited a significantly more rapid depletion of
       peripheral T-lymphocyte subsets as the experimental disease advanced.
       Using the polymerase chain reaction amplification and Southern blot
       detection, it was determined that the CD4+ cell carried the greatest
       proviral burden in peripheral lymphocytes subsets during the latter
       phases of the disease. Though not conclusive, it was demonstrated that
       provirus infection of the peripheral CD8+ lymphocyte is also likely.
       FeLV provirus was not detected in circulating surface immunoglobulin
       positive lymphocytes. Phenotypic characterizations of FeLV induced
       lymphomas from multiple tissues are also described. Seven of nine FeLV
       induced thymic lymphosarcomas were composed of abnormally high
       percentages of CD4-CD8+ lymphocytes, while 4/9 thymic tumors exhibited a
       predominant CD4+CD8+ phenotype. Six of nine splenic lymphosarcomas were
       partly composed of lymphocytes with a null phenotype (Pan T-, CD4-CD8- ,
       IgG-). The CD4+CD8- lymphocyte was under-represented in nearly all
       tissues examined. These results suggest that FeLV transforms a CD4+CD8+
       precursor and that transformation results in a
       differentiation/maturation arrest at the CD4+CD8+ stage. (Full text
       available from University Microfilms International, Ann Arbor, MI, as
       Order No. AAD93-27001)
 DE    Animal  B-Lymphocytes/MICROBIOLOGY/PATHOLOGY  Blotting, Southern  Cats
       Leukemia Virus, Feline/ISOLATION & PURIF  Leukemia,
       Feline/*BLOOD/PATHOLOGY  *Lymphocyte Subsets  Lymphoma,
       Diffuse/MICROBIOLOGY  Phenotype  Polymerase Chain Reaction
       Proviruses/ISOLATION & PURIF  T-Lymphocytes/MICROBIOLOGY/PATHOLOGY
       THESIS

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).