title: Peptide-induced immune protection of CD8+ T cell-deficient mice against Friend retrovirus-induced disease.
abstract: CD8+ CTLs and virus-neutralizing antibodies have been associated with spontaneous and vaccine-induced immune control of retroviral infections. We previously showed that a single immunization with an env gene-encoded CD4+ T cell epitope protected mice against fatal Friend retrovirus infection. Here, we analyzed immune cell components required for the peptide-induced anti-retroviral protection. Mice lacking CD8+ T cells were nevertheless protected against Friend virus infection, while mice lacking B cells were not. Virus-producing cells both in the spleen and bone marrow decreased rapidly in their number and became undetectable by 4 weeks after infection in the majority of the peptide-immunized animals even in the absence of CD8+ T cells. In the vaccinated animals the production and class switching of virus-neutralizing and anti-leukemia cell antibodies were facilitated; however, virus-induced erythroid cell expansion was suppressed before neutralizing antibodies became detectable in the serum. Further, the numbers of virus-producing cells in the spleen and bone marrow in the early stage of the infection were smaller in the peptide-immunized than in unimmunized control mice in the absence of B cells. Thus, peptide immunization facilitates both early cellular and late humoral immune responses that lead to the effective control of the retrovirus-induced disease, but CD8+ T cells are not crucial for the elimination of virus-infected cells in the peptide-primed animals.
authors.affiliation: Department of Immunology, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawabata
authors.forename: Atsuko
authors.initials: A
authors.lastname: Niwa
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Tsuji-Kawahara
authors.forename: Hirohide
authors.initials: H
authors.lastname: Uenishi
authors.forename: Norimasa
authors.initials: N
authors.lastname: Iwanami
authors.forename: Hideaki
authors.initials: H
authors.lastname: Matsukuma
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Abe
authors.forename: Nobutada
authors.initials: N
authors.lastname: Tabata
authors.forename: Haruo
authors.initials: H
authors.lastname: Matsumura
authors.forename: Masaaki
authors.initials: M
authors.lastname: Miyazawa
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D001402:B-Lymphocytes; D001853:Bone Marrow / Q000276:immunology / Q000821:virology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes; D018984:Epitopes, T-Lymphocyte / Q000008:administration & dosage* / Q000276:immunology; D005622:Friend murine leukemia virus / Q000276:immunology*; D015686:Gene Products, env / Q000008:administration & dosage* / Q000276:immunology; D007942:Leukemia, Experimental / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D012192:Retroviridae Infections / Q000276:immunology / Q000517:prevention & control*; D013154:Spleen / Q000276:immunology / Q000821:virology; D014412:Tumor Virus Infections / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D018984:Epitopes, T-Lymphocyte; D015686:Gene Products, env; D014765:Viral Vaccines