PSV-6 Effect of maternal undernutrition on gene expression related to immune system in spleen of Japanese Black (Wagyu) fetuses

Abstract

Listen

Translate article

Abstract Underdevelopment in the fetal period increases the risk of disease in the neonatal period, and there are concerns about the effects on later growth and fattening. Previous studies have indicated that poor nutrition during gestation affects not only the development of skeletal muscle and liver, but also the formation of the thymus gland and spleen, which are involved in immunity. The purpose of this study was to investigate the effects of maternal undernutrition on gene expression related to the immunity of the spleen. Multiparous Wagyu cattle (n = 12) were randomly assigned to two nutrition groups: the control group (CON: 120% of Japanese feeding standard for beef cattle; n = 6) and the maternal undernutrition group (MUN: 60% of Japanese feeding standard for beef cattle; n = 6) from conception to d 260 of gestation. Fetuses (n = 12) were harvested from the maternal cows and fetal spleens were collected. Total RNA was extracted from each spleen to synthesize cDNA. The quantitative RT-PCR (qRT-PCR) analysis was carried out to investigate the expression of 17 target genes [CD4, CD8a, CD8b, CD19, CD21, CD79a, CD205, interferon (IFN) -γ, NFk-β, toll-like receptor (TLR) 4, interleukin (IL) 2, IL4, IL6, IL7, IL10, IL18, and IFI16) related to the immune system. Ribosomal protein S18 was used as an internal control. The specificity of PCR products was confirmed by analyzing the dissociation curves. Data were analyzed by student t-test or Welch’s t-test after the Smirnov-Grubbs test and F-test to remove outliers and compare variances. The expression of CD8a (P < 0.1) and CD8b (P < 0.1) related to Cytotoxic T cell tended to be less in MUN than in CON (Figure 1). Other immunological cell marker genes expression (CD4, CD19, CD21, CD79a, CD205) did not show any significant differences between CON and MUN (P > 0.11). In genes related to immunological mechanisms (IFN-γ, NFk-β, TLR4, IL2, IL4, IL6, IL7, IL10, IL18, and IFI16), the expression of NFk-β was lless in MUN than in CON (P < 0.05). NFk-β was reported to regulate more than 400 genes including immune function. In addition, the expression of IL10 was less in MUN than in CON (P < 0.05). The cytokine of IL-10 has functions to suppress over-activated cytotoxic immunity by CD8+ T cell. These results might suggest that maternal undernutrition induces cytotoxic immune deactivation through NFk-β expression decline in the fetal spleen.