       Document 0070
 DOCN  M9640070
 TI    Mediation of immunity to Toxoplasma gondii oocyst shedding in cats.
 DT    9604
 AU    Davis SW; Dubey JP; Parasite Biology and Epidemiology Laboratory,
       Agricultural; Research Service, United States Department of
       Agriculture,; Beltsville, Maryland 20705-2350, USA.
 SO    J Parasitol. 1995 Dec;81(6):882-6. Unique Identifier : AIDSLINE
       MED/96130073
 AB    Immunity to Toxoplasma gondii, as measured by oocyst shedding, was
       studied in cats. In 3 trials, 12 3-mo-old T. gondii-free cats were fed
       tissue cysts of the ME-49 strain of T. gondii. All cats shed T. gondii
       oocysts for approximately 1 wk starting 3-5 days after ingesting tissue
       cysts. One cat became ill because of toxoplasmic pneumonia and was
       killed 17 days after inoculation. The remaining cats remained clinically
       normal. Approximately 3 mo after primary infection, these 11 cats
       (immune) and 11 age-matched or littermate uninfected cats (nonimmune)
       were challenged orally with tissue cysts of the ME-49 strain. In trials
       1 and 3, 1 immune and 1 nonimmune cat were killed at 36 hr, 60 hr, 5
       days, and 12 days after challenge and the development of T. gondii in
       intestines was studied histologically; in trial 2, cats were killed at
       36 hr, 60 hr, and 5 days only. None of the immune cats shed oocysts
       after challenge. Asexual T. gondii types were found at 36 and 60 hr and
       at 5 days, indicating partial development of T. gondii in the intestine
       of immune cats. There were no significant differences in lymphocyte
       CD4+/CD8+ from spleen, popliteal, and mesenteric lymph nodes of immune
       cats compared to nonimmune cats.
 DE    Animal  Cat Diseases/*IMMUNOLOGY/PARASITOLOGY  Cats  Concanavalin
       A/PHARMACOLOGY  CD4-Positive T-Lymphocytes  CD8-Positive T-Lymphocytes
       Disease Vectors  Feces/*PARASITOLOGY  Immunity, Active  Intestine,
       Small/PARASITOLOGY  Lymph Nodes/PARASITOLOGY  Lymphocyte Transformation
       Mice  Parasite Egg Count  Spleen/PARASITOLOGY  Toxoplasma/*IMMUNOLOGY
       Toxoplasmosis, Animal/*IMMUNOLOGY  JOURNAL ARTICLE

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

