Anatomy & Cell Biology  2010;43(1):25-35

doi:10.5115/acb.2010.43.1.25

Vitamin C acts indirectly to modulate isotype switching in mouse B cells.

Ami WOO 1 ; Jin Hee KIM ; Young Joo JEONG ; Hyung Gun MAENG ; Yong Taek LEE ; Jae Seung KANG ; Wang Jae LEE ; Young il HWANG

Affiliations

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Keywords

Vitamin C; antioxidant; reactive oxygen species; mouse B cell; isotype switching

Country

Republic of Korea

Language

English

Abstract

Vitamin C, one of essential micronutrients, has been reported to modulate the humoral immune responses in some mammals. We investigated whether vitamin C might modulate this response in mice by directly affecting B cells. Splenic B cells were isolated and activated by CD40- and B cell receptor-ligation in vitro. The cells were cultured with a pretreatment of vitamin C from 0 to 1 mM of concentrations. Vitamin C slightly increased apoptosis of B cells dose-dependently and behaved as an antioxidant. We found that in vivo administration of vitamin C by intraperitoneal injection affected isotype switching as previously reported: the titer of antigen-specific IgG1 antibody was decreased, while that of IgG2a was unaffected. Somewhat different from those observed in vivo, in vitro exposure to vitamin C slightly decreased isotype switching to IgG1 and increased isotype switching to IgG2a. Pretreatment with vitamin C in the safe range did not affect either proliferation of cultured B cells or the expression of CD80 and CD86 in those cells. Taken together, in vivo results suggest that vitamin C acts to modulate isotype switching in the mouse. However, because of our in vitro results, we suggest that the modulation exerted by vitamin C in vivo is by indirectly affecting B cells, perhaps by directly influencing other immune cells such as dendritic cells.