Repeated oronasal exposure to lipopolysaccharide induced mucosal IgA responses in periparturient dairy cows.

This study investigated the effects of repeated oronasal treatment with lipopolysaccharide (LPS) on the humoral immune responses in saliva, vaginal mucus, and the plasma markers of the acute phase response in periparturient dairy cows. One hundred pregnant Holstein cows were administered either 3 increasing doses of LPS (n = 50) as follows: 1) 0.01 µg/kg body weight (BW) on d -28, 2) 0.05 µg/kg BW on d -25, and -21, and 3) 0.1 µg/kg BW on d -18, and -14, or sterile saline solution (controls; n = 50) oronasally for 3 consecutive wk starting at 28 d before parturition. Intensive sampling was conducted on thirty cows (n = 15/group). Multiple saliva, vaginal mucus and blood samples were collected around parturition and analyzed for total immunoglobulin-(Ig)A, plasma serum amyloid A (SAA), lipopolysaccharide-binding protein (LBP), anti-LPS IgA, IgG, IgM, tumour necrosis factor(TNF)-α, and interleukin(IL)-1. Results regarding total secretory IgA (sIgA) antibodies showed greater concentrations in the saliva and an overall tendency for higher total sIgA in the vaginal mucus of the LPS-treated cows. Treatment had no effect on plasma sIgA, IgG, IgM anti-LPS antibodies, haptoglobin, SAA, LBP, TNF-α, and IL-1. Treatments by time interactions were observed for SAA and IL-1 with lowered concentrations of both variables in the plasma of LPS-treated cows after parturition. Overall, repeated oronasal LPS treatment clearly enhanced total sIgA antibodies in the saliva, stimulated their production in vaginal mucus shortly before calving, and lowered plasma IL-1 around parturition, but showed limited effects on markers of the acute phase response in the plasma in dairy cows around parturition

Concentrations of plasma serum amyloid A (a), and lipopolysaccharide binding protein (b), in periparturient Holstein cows primed oronasally with LPS (▪) or saline (⋄).

<p>Cows in the LPS group were administered orally and nasally 2(0.15 M of NaCl), respectively, containing 3 increasing doses of LPS from <i>E. coli</i> 0111:B4 as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, whereas control cows received 2 mL oral and 1 mL nasal sterile saline solution. (LSM ± SEM; n = 15; Trt  =  effect of treatment; Time  =  effect of sampling day, Trt×time  =  effect of treatment by sampling day; * indicates treatment differences at specific time points at <i>P</i><0.05).</p

Concentrations of plasma haptoglobin in periparturient Holstein cows primed oronasally with LPS (▪) or saline (⋄).

<p>Cows in the LPS group were administered orally and nasally 2(0.15 M of NaCl), respectively, containing 3 increasing doses of LPS from <i>E. coli</i> 0111:B4 as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, whereas control cows received 2 mL oral and 1 mL nasal sterile saline solution. (LSM ± SEM; n = 15; Trt  =  effect of treatment; Time  =  effect of sampling day, Trt×time  =  effect of treatment by sampling day; *indicates treatment differences at specific time points at <i>P</i><0.05).</p

Concentrations of total salivary (a) or vaginal (b) immunoglobulin(Ig) A in periparturient Holstein cows primed oronasally with LPS (▪) or saline (⋄).

<p>Cows in the LPS group were administered orally and nasally 2(0.15 M of NaCl), respectively, containing 3 increasing doses of LPS from <i>E. coli</i> 0111:B4 as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, whereas control cows received 2 mL oral and 1 mL nasal sterile saline solution. (LSM ± SEM; n = 15; Trt  =  effect of treatment; Time  =  effect of sampling day, Trt×time  =  effect of treatment by sampling day; *indicates treatment differences at specific time points at <i>P</i><0.05).</p

Concentrations of plasma immunoglobulin(Ig)-A (a), IgG (b), and IgM (c) in periparturient Holstein cows primed oronasally with LPS (▪) or saline (⋄).

<p>Cows in the LPS group were administered orally and nasally 2(0.15 M of NaCl), respectively, containing 3 increasing doses of LPS from <i>E. coli</i> 0111:B4 as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, whereas control cows received 2 mL oral and 1 mL nasal sterile saline solution. (LSM ± SEM; n = 15; Trt  =  effect of treatment; Time  =  effect of sampling day, Trt×time  =  effect of treatment by sampling day).</p

Concentrations of plasma interleukin-1 (a) and tumour necrosis factor-α (b) in periparturient Holstein cows primed oronasally with LPS (▪) or saline (⋄).

<p>Cows in the treatment group were administered orally and nasally 2(0.15 M of NaCl), respectively, containing 3 increasing doses of LPS from <i>E. coli</i> 0111:B4 as follows: 1) 0.01 µg/kg body weight (BW) on d −28, 2) 0.05 µg/kg BW on d −25, and −21, and 3) 0.1 µg/kg BW on d −18, and −14, whereas control cows received 2 mL oral and 1 mL nasal sterile saline solution. (LSM ± SEM; n = 15; Trt  =  effect of treatment; Time  =  effect of sampling day, Trt×time  =  effect of treatment by sampling day; * indicates treatment differences at specific time points at <i>P</i><0.05).</p