Immune Cells In Bovine Mesenteric Adipose Tissue
Date
2016-05
Authors
Journal Title
Journal ISSN
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Publisher
University of Delaware
Abstract
Modern nutritional programs in the dairy industry are designed to increase the
size of the adipose mass during late lactation. The objective is to increase nutrient
reserves that can be mobilized later to meet the overwhelming energy demands of
heavy milk production in the next lactation. In addition, the energy density of rations
is increased to elevate energy intake at the time of heavy lactation. In human and
murine obesity models, these two practices are linked to metabolic disorders. Dietary
elements trigger intestinal mucosal inflammation, erode intestinal permeability barrier
functions, and enable endotoxins to translocate from the gut to the systemic
circulation. Adipose depots overburdened with nutrients trigger immune cells to
infiltrate the fat. Translocated endotoxins target these cell infiltrates and establish a
pro-inflammatory milieu in the adipose depot. The inflammation generates Type 2
diabetes, lipolysis, dyslipidemia, and steatohepatitis.
Increasing morbidity due to metabolic disorders in heavily lactating cows is
testimonial to the intractable nature of this problem in the dairy industry. Interactions
between diet-induced shifts in the gut microbiome and the nutrient-laden adipose
depot present an interesting approach to better understand the pathogenesis, and
therefore to control this disorder in dairy cows.
Our objective was to determine the presence of helper T cell and dendritic cell
populations in bovine mesenteric adipose tissue. Endogenous populations of T cells, T
lymphocytes, and dendritic cells do exist in bovine mesenteric adipose tissue. The results of this experiment confirm the presence of dendritic cells in the
bovine mesenteric adipose tissue. The stromal cell fraction of the mesenteric adipose
tissue (MAT) was made up of cells that expressed MHC II+ (10.62 ± 0.86%), CD209+
(2.05 ± 0.10%), CD209+/CD11b+ (1.45 ± 0.23%), and CD3+ (3.74 ± 2.16%). The
results further suggest that immune function has an impact on metabolic homeostasis
in the bovine.
The importance of this research is to determine the effects of the current
nutritional standards of the dairy industry, which purposefully increase adiposity in
dairy cows. Our data indicates that components of the innate and adaptive immune
response are endogenous to the bovine mesenteric adipose depot. Their presence could
contribute to insulin resistance, dyslipidemia, and chronic inflammatory disease
coincident with nutrient overburdened adipocytes.
Description
Keywords
pre-veterinary medicine, animal biosciences, cells