Effect of High Dietary Manganese on the Immune Responses of Broilers Following Oral Salmonella typhimurium Inoculation

Abstract

Manganese (Mn) is an essential nutrient for both host and pathogen. Recent studies have demonstrated the nutritional immunity of Mn against Salmonella infection in mammals. To investigate the effect of high dietary Mn on immune responses of broilers following Salmonella challenge, 144 1-day-old male broilers were fed a basal diet (containing 20.04 mg Mn/kg) plus an additional 40 (the control group) or 400 mg Mn/kg (the H-Mn group) for 7 days. The 72 broilers in each group were then orally inoculated with 5 × 10 CFUs of Salmonella typhimurium (ATCC#14028) or phosphate-buffered saline. Peripheral blood, spleens, cecal tonsils, and bursa of Fabricius were collected from Salmonella-inoculated and Salmonella-noninoculated broilers (n = 6) at 2 days post inoculation (2 DPI) and 7 days post inoculation (7 DPI). Peripheral blood lymphocyte subpopulations were determined by flow cytometry. The messenger RNA (mRNA) abundance of genes was determined by quantitative real-time polymerase chain reaction. Salmonella counts were higher (P < 0.05) in the H-Mn group than that in the control group at 2 DPI in the cecal contents of Salmonella-inoculated broilers. High dietary Mn increased CD3CD4 and CD3CD8 percentages in the peripheral blood of Salmonella-inoculated broilers at 2 DPI. Salmonella inoculation increased interleukin (IL)-6 mRNA expression in spleens and bursa of Fabricius at 2 DPI and increased IL-1β and IL-6 mRNA expression in cecal tonsils at 7 DPI in the H-Mn group. These changes were not observed in the control group. High dietary Mn increased interferon-γ (IFN-γ) in spleens and decreased IFN-γ and IL-12 mRNA expression in cecal tonsils of Salmonella-inoculated broilers at 2 DPI. High dietary Mn decreased IL-17 mRNA expression in the bursa of Fabricius at 7 DPI, but increased this expression in cecal tonsils at 2 and 7 DPI in Salmonella-inoculated broilers. These results suggested that dietary Mn level affected T helper (Th) 1-cytokine reaction in spleens and cecal tonsils, and Th17-mediated immunity in cecal tonsils and the bursa of Fabricius of broilers when challenged with Salmonella.

The Systemic Zinc Homeostasis Was Modulated in Broilers Challenged by Salmonella

“…On day 7, broilers were orally inoculated with either 0 or 0.5 × 10 8 CFU Salmonella enterica serovar Typhimurium (ST), according to the previous assignment (non-challenged vs. challenged). The method is detailed elsewhere [22]. The strain of ST used in this experiment was from the American Type Culture Collection (ATCC, No.…”

“…2), which is considered to be a response by the host defence system. A great deal of literature has already revealed that immune organs play crucial roles in the defence against Salmonella [22]. Whether the host will alter the zinc metabolism of their immune organs in response to Salmonella challenge remains unknown until now.…”

Impact of Dietary Manganese on Intestinal Barrier and Inflammatory Response in Broilers Challenged with Salmonella Typhimurium

“…Meanwhile, inflammatory cytokines such as interleukin (IL)-1, IL-6, IL-17, and IL-22, together with interferon-γ (IFN-γ) are released after infection, either by epithelial cells, resident phagocytes, infiltrating phagocytes, and/or lymphocytes in the cecum [3,10,11]. Recent data from our laboratory demonstrates that a similar cytokine gene expression pattern can be recorded in spleen, thymus, and bursa of broilers [12]. Oral S. Typhimurium challenge also was found to change the cluster of differentiation 4 (CD 4+ ) and CD 8+ cells ratios and increase the gene expression of IL-1β, IL-8, IFN-γ, and IL-18 in the spleens of hens, similar to the response in the cecum after oral infection with Salmonella [13].…”

“…It is also an essential trace element of normal metabolism in humans and animals. The roles that Mn plays in innate and adaptive immune responses are well established in broilers [12], rats [16], and humans [17]. For instance, adding Mn to a diet could increase the phagocytic ability of natural killer cells of rats [16].…”

Evaluating the effects between metal mixtures and serum vaccine antibody concentrations in children: a prospective birth cohort study

“…However, there is evidence that high levels of manganese may impair immune function. Experimental studies in rodents and birds have shown that manganese exposure can cause a significant changes in lymphocyte responses and reduced antibody production [14], as well as increased susceptibility to bacterial and viral infection [15,16]. Although epidemiologic evidence of manganese-related immunological effects is primarily restricted to occupational studies of adult men, high occupational exposure has been associated with significantly altered lymphocyte profiles (e.g.…”