Dietary ribonucleotides modulate type 1 and type 2 T-helper cell responses against ovalbumin in young BALB/cJ mice.
Dietary ribonucleotides have been shown to augment type 1 T-helper cell (Th1) responses to a protein antigen (Ag) in Th1-prone C57BL/6 mice, but their effects on type 2 Th (Th2)-prone mice are unknown. BALB/cJ mice have skewed Th2 responses against ovalbumin (OVA), characterized by augmented production of Th2 cytokines and immunoglobulin (Ig)G1/IgE antibodies (Ab); Th1 responses augment IgG2a Ab production, whereas Th2 responses augment IgG1/IgE Ab production. In this study, we determined the effects of dietary ribonucleotides obtained from yeast on the balance of Th1/Th2 responses against OVA in young BALB/cJ mice. Mice were fed a ribonucleotide-free (NF) or ribonucleotide-supplemented (NS) diet (4.74 g nucleotides/kg diet) and given OVA (10 microg/dose) with incomplete Freund's adjuvant (IFA) at 3 and 6 wk. We assessed T-cell responses in the regional draining lymph nodes (LN) by measuring production and expression of Th1/Th2 cytokines, interferon-gamma (IFN-gamma) and interleukin-5 (IL-5), respectively. Anti-OVA IgG subclass and IgE Ab levels were determined 3 wk after the first OVA challenge and 5 d and 2 wk after the second OVA challenge. Dietary ribonucleotides significantly augmented OVA-specific IFN-gamma production by the regional draining LN cells after the first and second OVA challenges. The NS diet increased anti-OVA IgG2a Ab levels after the first OVA challenge and both anti-OVA IgG2a and anti-OVA IgG2b after the second challenge. OVA-specific IgG1 and IgE Ab levels were lower (P < 0.05) after the second OVA challenge in mice fed the NS diet. Dietary ribonucleotides did not affect production or expression of IL-5. Our findings thus indicate that in Th2-prone BALB/c J mice, dietary ribonucleotides modulated skewed Th2 responses against OVA toward Th1 as measured by production of IFN-gamma, a Th1 cytokine, and changes in anti-OVA Ab isotype levels.
Jyonouchi
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Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA. jyono001@tc.umn.edu
Sun
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Winship
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Kuchan
M J
MJ
D000818:Animals; D000906:Antibodies / Q000032:analysis; D004032:Diet; D005260:Female; D007073:Immunoglobulin E / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D015848:Interleukin-5 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D012265:Ribonucleotides / Q000008:administration & dosage* / Q000494:pharmacology; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D007074:Immunoglobulin G; D015848:Interleukin-5; D012333:RNA, Messenger; D012265:Ribonucleotides; D007073:Immunoglobulin E; D007371:Interferon-gamma; D010047:Ovalbumin