title: High levels of IL-4 and IL-10 mRNA and low levels of IL-2, IL-9 and IFN-gamma mRNA in MuLV-induced lymphomas.
abstract: The expression of cytokines may influence the development of lymphoma in retrovirally infected animals in at least two ways: (1) cytokines in the tumor environment may stimulate the proliferation of tumor cells and/or (2) cytokines in the tumor environment may diminish the cell-mediated antitumor immune response. To evaluate these possibilities, a semiquantitative RT-PCR approach was utilized to permit a broad screening of cytokine mRNAs in a large number of tissue samples. Examination of MuLV-induced end-stage lymphomas revealed the absence of mRNA for cytokines known to stimulate the proliferation of T cells (i.e., IL-2, IL-9), the absence of mRNA for cytokines known to enhance cell-mediated antitumor immune responses (i.e., IL-2, IFNgamma), and the presence of mRNA for cytokines known to diminish such responses (i.e., IL-4, IL-10). Similar patterns of cytokine mRNA expression were detected in tumor-derived cell lines. Spleen and thymus from animals collected longitudinally during infection and from age-matched uninfected mice also demonstrated a similar pattern, except that IFNgamma mRNA was readily detectable. These findings do not support the hypothesis that the developing tumor depends on cytokines to provide proliferative signals. The findings suggest that cytokines in the immediate environment of the lymphoma support tumor development by acting to diminish an effective antitumor immune response.
authors.affiliation: Program in Molecular and Cellular Biology, Tulane Medical School, New Orleans, Louisiana 70112, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Beaty
authors.forename: K
authors.initials: K
authors.lastname: Rulli
authors.forename: K L
authors.initials: KL
authors.lastname: Bost
authors.forename: J
authors.initials: J
authors.lastname: Pantginis
authors.forename: J
authors.initials: J
authors.lastname: Lenz
authors.forename: L S
authors.initials: LS
authors.lastname: Levy
mesh_terms: D000818:Animals; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology*; D015967:Gene Expression Regulation, Viral / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D016906:Interleukin-9 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D009052:Leukemia Virus, Murine / Q000235:genetics / Q000276:immunology*; D007942:Leukemia, Experimental / Q000235:genetics / Q000276:immunology*; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012192:Retroviridae Infections / Q000235:genetics / Q000276:immunology*; D014412:Tumor Virus Infections / Q000235:genetics / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D016906:Interleukin-9; D012333:RNA, Messenger; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma