Adjuvant effect of zinc oxide on Th2 but not Th1 immune responses in mice.
OBJECTIVE
We investigated the effect of zinc oxide (ZnO) on Th1 and Th2 immune responses in mice.


METHODS
Mice were intraperitoneally administered with ovalbumin (OVA) with or without varying doses of ZnO (day 0). On day 21, anti-OVA IgG, IgG2a, IgG1, and IgE antibodies in sera, OVA-specific proliferative responses of spleen cells, and production of Th1 cytokines including IFN-gamma as well as Th2 cytokines such as IL-4 and IL-5 were measured.


RESULTS
The results showed that administration of OVA with ZnO was followed by greater increases in anti-OVA IgG and the antigen-specific splenocyte proliferation compared to that of OVA alone. The production of anti-OVA IgG1 and IgE and secretion of IL-4 and IL-5 were markedly enhanced by ZnO. The enhancing effect of ZnO on these Th2 responses was as strong as aluminium hydroxide (Alum) that was widely used as an adjuvant. In contrast, treatment with OVA plus ZnO failed to affect production of anti-OVA IgG2a as well as IFN-gamma. It was also observed that ZnO had a stimulating effect on the secretion of the proinflammatory cytokine IL-17 from a new lineage of effector Th cells.


CONCLUSIONS
These results suggest that ZnO appears to have an adjuvant effect on the immune system, especially Th2 but not Th1 immune responses.
Matsumura
Misa
M
Department of Pharmacology, Kobe Pharmaceutical University, Kobe, Hyogo, Japan.
Nagata
Masafumi
M
Nakamura
Kazuichi
K
Kawai
Motoyuki
M
Baba
Takahiko
T
Yamaki
Kouya
K
Yoshino
Shin
S
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010047:Ovalbumin / Q000276:immunology; D018417:Th1 Cells / Q000187:drug effects* / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects* / Q000276:immunology; D015034:Zinc Oxide / Q000494:pharmacology*
D000276:Adjuvants, Immunologic; D016207:Cytokines; D010047:Ovalbumin; D015034:Zinc Oxide