Modulation by bovine lactoferrin of parameters associated with the IgA response in the proximal and distal small intestine of BALB/c mice.
BACKGROUND
Secretory IgA (SIgA) and the polymeric immunoglobulin receptor (pIgR) have a pivotal role in gut homeostasis. Bovine lactoferrin (bLf) has been shown to modulate intestinal immunity and endogenous corticosterone. Considering the regionalization of the intestinal immune response, the aim of this work was to compare the impact of bLf on the IgA response in the proximal versus distal small intestine under physiological conditions.


METHODS
Groups of healthy male BALB/c mice were orally treated with one daily dose of bLf (50, 500, or 5000 μg) or untreated (control) for 7 d, and then sacrificed. From plasma samples, corticosterone levels were determined by an enzyme-linked immunosorbent assay (ELISA) kit. From distal and proximal segments of the small intestine, the following material was obtained: intestinal secretions to evaluate IgA levels by ELISA; epithelial cell extracts for protein-analysis of α-chain and pIgR by Western blot; mucosa samples for mRNA analysis of α-/J-chain, pIgR, and interleukin (IL)-2, -4, -5, and -6 by real-time quantitative reverse transcription polymerase chain reaction (RT-PCR).


RESULTS
With 5000 μg of bLf, there were greater modulatory effects in the distal (versus proximal) segment, evidenced by an increase in the (i) level of total and specific IgA, (ii) protein expression of α-chain and pIgR, (iii) mRNA transcripts of α-chain, IL-2 and IL-5, and (iv) level of plasma corticosterone.


CONCLUSIONS
Endogenous corticosterone elicited by bLf may have allowed for an IL profile that favored the IgA antibody response. The latter has a key role in maintaining intestinal homeostasis.
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
Marycarmen
M
Godínez-Victoria
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
Teresita Rocío
TR
Cruz-Hernández
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
Humberto
H
Reyna-Garfias
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
Reyna Elizabeth
RE
Barbosa-Cabrera
b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana, Unidad Xochimilco , Ciudad de México , México.
Maria Elisa
ME
Drago-Serrano
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
María Cristina
MC
Sánchez-Gómez
a Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional , Ciudad de México , México.
Rafael
R
Campos-Rodríguez
D000284:Administration, Oral; D000818:Animals; D002417:Cattle; D016207:Cytokines / Q000276:immunology*; D018928:Immunity, Mucosal / Q000187:drug effects*; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007413:Intestinal Mucosa / Q000276:immunology*; D007421:Intestine, Small / Q000382:microbiology*; D007781:Lactoferrin / Q000494:pharmacology*; D008297:Male; D051379:Mice
D016207:Cytokines; D007071:Immunoglobulin A, Secretory; D007781:Lactoferrin
Bovine lactoferrin; IL-2; IL-5; SIgA; pIgR