title: Suppressive effects of Lactobacillus casei cells, a bacterial immunostimulant, on the incidence of spontaneous thymic lymphoma in AKR mice.
abstract: The mean survival age of female AKR/J mice was significantly prolonged, the enlargement of thymus was markedly suppressed, and the proliferation of ecotropic and recombinant murine leukemia viruses (MuLV) was markedly inhibited when 8-week-old female AKR/J mice were injected intraperitoneally (i.p.) with heat-killed Lactobacillus casei cells twice weekly for 8 weeks. In contrast, such actions of heat-killed L. casei cells were not seen in 20-week-old female AKR/J mice. The leukemogenic activity of the cell-free extract of thymus from adult female AKR/J mice in newborn female AKR/J mice was drastically reduced by i.p. treatment with heat-killed L. casei cells. The difference in adjuvant effectiveness of heat-killed L. casei cells on 8- and 20-week-old animals may be dependent on the difference in the enhancing activity of the cell-mediated immune systems between the groups induced by heat-killed L. casei cells, and, as a result, on the difference in the degree of proliferation of ecotropic and recombinant MuLV in thymus, which consequently causes thymic lymphoma.
authors.affiliation: Department of Clinical Nutrition, Faculty of Health Science, Suzuka University of Medical Science and Technology, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000367:Age Factors; D000818:Animals; D005260:Female; D007780:Lacticaseibacillus casei / Q000276:immunology*; D009052:Leukemia Virus, Murine / Q000187:drug effects; D008223:Lymphoma / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008806:Mice, Inbred AKR; D009929:Organ Size / Q000187:drug effects; D015996:Survival Rate; D013950:Thymus Gland / Q000187:drug effects / Q000473:pathology / Q000821:virology; D013953:Thymus Neoplasms / Q000517:prevention & control*
chemical_list: D000276:Adjuvants, Immunologic