XII - 12th International Symposium - Digestive Physiology of Pigs

Digestive
Physiology
of Pigs
and reared under gnotobiotic conditions. Piglets were either
given CF within 1 h after birth or were given sterile media.
At times 0, 8, 24, 48, and 72 h after birth, piglets were
euthanized and samples of spleen taken. Splenic cells from
individual piglets were isolated and cultured with or without
concanavalin A (conA). Splenic cells from CF treated piglets
had increased levels of IL1β, IFNγ, IL18, and IL10 at 8 h
after birth compared with control piglets as measured by
porcine cytokine ELISA. The increased levels of cytokines
produced by CF treated piglet splenocytes then declined
over time, returning to levels observed in control pigs, or
in some instances, below control levels. These results
suggest that CF may act as a modulator for certain aspects
of innate immune development.
Key words: commensal bacteria, innate immunity, gnotobiotic
piglets
2024 The effects of immune stressors on porcine
intestinal epithelial cell integrity and inflammation. V.
Mani* 1,5 , S. C. Pearce 2,5 , A. J. Harris 3,5 , T. E. Weber 4 , and
N. K. Gabler 1,5 , 1 Department of Animal Science, Interdepartmental
Toxicology Program, 2 Interdepartmental
Nutritional Sciences Program, 3 Department of Animal Science,
4 USDA-ARS, Ames, Iowa, USA, 5 Iowa State University,
Ames, Iowa, USA.
Intestinal epithelial cells continually encounter luminal
pathogens, immunogens and toxins. However, data
regarding the effects of these substances on intestinal
integrity and function in pigs are limited. Our study
objective was to examine the effect of immunogens
on barrier integrity and inflammation in IPEC-J2 cells.
Cells were plated on 0.4 μm pore size collagen coated
transwells, where they form a single confluent monolayer,
polarize and form tight junctions (TJ). The transepithelial
electrical resistance (TER) was measured to evaluate TJ
formation and integrity along with FITC-Dextran (FD, 4
kDa) macromolecule permeability. When the cells attained
peak TER, approximately 9 d post confluence, cells were
treated with the immune agonists lipopolysaccharide (LPS,
10 μg/ml, E.coli 055:05), PolyI:C (PIC, 20 μg/ml), zymosan
(ZYM, 100 μg/ml) and deoxynivalenol (DON, 20 μm) on the
luminal side, or with tumor necrosis factor α (TNFα) and
interleukin 1β (IL1β) on the basolateral side for 48 h. The
TER and FD permeability was assessed for membrane
integrity. Interleukin 8 (IL-8) secreted into the media was
measured as a marker of inflammation. After 48 h of DON or
TNFα treatment, TER was significantly reduced compared
to the non-challenged control (P < 0.05; 53 and 63%,
respectively). The TER was not different from the control
when cells were exposed to ZYM, PIC or IL1β. Further,
FD permeability did not differ between the treatments.
Compared to the control, media IL-8 concentrations were
increased by TNFα and LPS (P < 0.05; 0.03, 2.68 and 0.96
ng/ml, respectively). Treatment with PIC and ZYM did not
increase IL-8 secretion (P > 0.10; 0.61 and 0.31 ng/ml
respectively). These data indicate that IPEC-J2 cells are
particularly responsive to inflammation and barrier integrity
modifications induced by DON, TNFα and LPS. However,
barrier integrity appears to be maintained under most
challenge conditions.
XII INTERNATIONAL SYMPOSIUM ON
DIGESTIVE PHYSIOLOGY OF PIGS
101
Session III
Key words: intestinal epithelial cells, inflammation, intestinal
integrity
2025 The effects of zinc on the adaptive T cell immune
response in weaning piglets. S. Kreuzer,* J. Schulte, J.
Assmus, and G. A. Brockmann, Humboldt-Universität zu
Berlin, Breeding Biology and Molecular Genetics, Berlin,
Germany.
Because mechanisms contributing to positive effects of
zinc on health in pigs are unclear, we examined how the
adaptive T cell immune response could be affected by
zinc. After weaning at 26 ± 1 d, Landrace piglets were fed
a starter diet supplemented with a low (57 ppm, group A),
moderate (164 ppm, group B), or high zinc concentration
(2425 ppm, group C) over a period of 4 weeks. Immune cells
of the blood as well as mesenteric lymph nodes (LN) and
Peyer’s Patches (PP) were analyzed by flow cytometry 1, 2,
3, and 4 wk after weaning (n = 6 per group). Furthermore,
expression of the master transcription factors FOXP3 and
TBET were assessed by quantitative RT-PCR. Feeding of
a high zinc level was accompanied with high growth rates
during the first week after weaning in group C (9.47 kg vs.
8.43 and 8.33 in the groups A and B, respectively), while
longer feeding led to growth impairment until 4 wk after
weaning when piglets of group C were the lightest (P <
0.001). Higher frequencies of CD4 + CD25 high regulatory T
cells were found in blood (P < 0.06), and in ileal LN (P <
0.03) and PP (P < 0.05) of group C compared with B 1
wk and in particular 2 wk after weaning. These findings are
consistent with higher transcript amounts of the FOXP3 in
ileal and jejunal LN in group C 1 wk after weaning. The high
frequency of CD4 + CD25 high regulatory T cells in ileal PP was
associated with significantly lower CD8a high cytotoxic T cells
and CD4 + T helper cells (P < 0.005) with most CD4 + T helper
cells activated (CD4 + CD8 dim ). Four weeks after weaning,
the positive effects of zinc were no longer detectable
neither on the cell nor the transcript level. But, at the same
age, TBET, the master transcription factor of Th1 cells,
was higher expressed in jejunal LN of the groups A and C
compared with B (P < 0.05) suggesting a high proliferation
rate of naive T helper cells toward proinflammatory Th1
cells. In conclusion, short-term feeding of a high level of
zinc around the critical time of weaning may have beneficial
effects on growth and activation of the immune system,
while continued low or high zinc supply can lead to impaired
growth and loss of the positive effects on the T cell immune
response.
Key words: piglets, zinc, T cells
2026 The effects of dam parity on microbial diversity
in milk, and the in vitro effects of digested milk
on immunoglobulin transport and neonatal Fc receptor
expression in IPeC-J2 cells. S. E. Tangeman, E. E.
Hinkle,* H. Tran, and T. E. Burkey, University of Nebraska-
Lincoln, Lincoln, NE, USA.
Gastrointestinal (GI) health is impacted by interactions
between microbes, epithelial cells, and the mucosal
immune system. Bacteria in milk can affect the GI microbial
profile of progeny and recent studies suggest that progeny