       Document 0069
 DOCN  M9640069
 TI    Preimmune resistance to Toxoplasma gondii in aged and young adult mice.
 DT    9604
 AU    Johnson LL; Gibson GW; Sayles PC; Trudeau Institute, Inc., Saranac Lake,
       New York 12983, USA.
 SO    J Parasitol. 1995 Dec;81(6):894-9. Unique Identifier : AIDSLINE
       MED/96130075
 AB    Aged individuals are more susceptible to certain infections than are
       young adults. To investigate the relative resistance capabilities of
       aged and young adult mice, responses that are induced within the first
       week of a Toxoplasma gondii infection, which are known to be involved in
       preimmune resistance, were compared in young adult and aged mice. Aged
       mice did not differ reproducibly from young adults in numbers of induced
       Thy-1+ CD4- CD8- cells or interferon-gamma levels. Numbers of induced
       CD4+ and CD8+ T cells, associated with acquired immunity, were as high
       in aged mice as in young adults. Natural killer cell activity, although
       induced to a high level, was lower in aged mice. Aged mice thus are
       capable of inducing a mechanism of preimmune resistance to T. gondii and
       presumably other infectious agents. Nonetheless, aged mice died within
       8-12 days after intraperitoneal or peroral inoculation of 500 T. gondii
       cysts, whereas young adult mice survived. Causes other than an
       age-related impairment in preimmune resistance mechanisms are apparently
       responsible for the increased susceptibility of aged mice to T. gondii
       infection.
 DE    Aging/*IMMUNOLOGY  Animal  Antigens, Thy-1  CD4-Positive T-Lymphocytes
       CD8-Positive T-Lymphocytes  Female  Immunity, Cellular  Immunity,
       Natural  Interferon Type II/BIOSYNTHESIS  Killer Cells, Natural  Mice
       Mice, Inbred C57BL  Mice, Inbred DBA  Peritoneal Lavage  Support,
       Non-U.S. Gov't  Survival Analysis  T-Lymphocyte Subsets
       Toxoplasma/*IMMUNOLOGY  Toxoplasmosis,
       Animal/*IMMUNOLOGY/MORTALITY/PATHOLOGY  JOURNAL ARTICLE

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

