Arachidonic acid-and docosahexaenoic acid-enriched formulas modulate antigen-specific T cell responses to influenza virus in neonatal piglets.
BACKGROUND
Whereas the immunomodulatory effects of feeding either arachidonic acid (AA) or docosahexaenoic acid (DHA) separately have been previously investigated, little is known about the immunomodulatory efficacy of AA or DHA when they are fed in combination as infant formula ingredients.


OBJECTIVE
The objective of this study was to investigate the ability of AA- and DHA(AA/DHA)-enriched infant formula to modulate immune responses in the neonate in response to an inactivated influenza virus vaccine.


METHODS
Neonatal piglets (n = 48) were weaned on day 2 of age and distributed into 16 blocks of 3 littermate piglets each. Within each block, piglets were randomly assigned to a control formula, AA/DHA-enriched formula (0.63% AA and 0.34% DHA), or sow milk for 30 d. On day 9, 8 blocks of piglets were immunized with an inactivated influenza virus vaccine. On days 0, 9, 16, 23, and 30 after weaning, we measured influenza virus-specific T cell proliferation and phenotype of T subsets in peripheral blood. A delayed-type hypersensitivity reaction test was administered on day 28. Cytokine messenger RNA expression was determined by quantitative real time reverse transcriptase-polymerase chain reaction on day 30.


RESULTS
The influenza virus-specific CD4(+) and CD8(+) T cell ex vivo lymphoproliferative responses were significantly lower on day 23 after immunization in piglets receiving dietary AA/DHA supplementation and sow milk than in those receiving the unsupplemented control formula. The immunomodulatory effects of AA/DHA-enriched formulas were consistent with up-regulation of interleukin 10 in peripheral blood mononuclear cells.


CONCLUSIONS
Overall, it appears that the AA/DHA-enriched formula modulated antigen-specific T cell responses in part through an interleukin 10-dependent mechanism.
Bassaganya-Riera
Josep
J
Nutritional Immunology & Molecular Nutrition Laboratory, Department of Human Nutrition Foods and Exercise, Virginia Tech University, Blacksburg, VA 24060, USA. jbassaga@vt.edu
Guri
Amir J
AJ
Noble
Alexis M
AM
Reynolds
Kathryn A
KA
King
Jennifer
J
Wood
Cynthia M
CM
Ashby
Michael
M
Rai
Deshanie
D
Hontecillas
Raquel
R
D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D023421:Models, Animal; D009976:Orthomyxoviridae Infections / Q000276:immunology*; D013552:Swine; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid