Effects of free amino acids on cytokine secretion and proliferative activity of feline T cells in an in vitro study using the cell line MYA-1

Abstract

In vitro studies might be an interesting screening method for targeted in vivo studies in the field of immunonutrition and help to reduce and refine animal studies. As the role of amino acids for immune function of cats has not been evaluated in detail so far, the present study aimed at investigating the effects of eight different amino acids (arginine, leucine, isoleucine, valine, glutamine, lysine, threonine and tryptophan) in six concentrations each (0, 0.25, 0.5, 1, 2 and 8x the cat blood level) on cytokine secretion and proliferative activity of feline T cells (MYA-1) in vitro. The results demonstrated that high doses of arginine increased IL-4, IL-10 and TNF-a secretion of T cells, while increasing concentrations of lysine increased IL-10 secretion and proliferative activity of the T cells. High doses of leucine enhanced GM-CSF and IL-10 secretion, while concentrations of threonine in the cell culture media greater than blood concentration also increased GM-CSF and additionally TNF-a secretion of the cells. The effects of glutamine and isoleucine on T cell function were only small. In conclusion, the present in vitro study could evaluate the immunomodulating potential of specific amino acids for feline T cell function. High doses of arginine, lysine, leucine and threonine had a significant impact on cytokine secretion and proliferative activity of the T cells. Targeted in vivo studies should investigate the clinical relevance of dietary supplementation of those amino acids in healthy and diseased cats as a next step.

Effects of arginine and ornithine supplementation to a high‐protein diet on selected cellular immune variables in adult cats

“…The results contrast with data previously observed in cats, where a dietary arginine supplementation led to an increase of the proliferative and phagocytic activity of blood leukocytes . In addition, an in vitro study could also demonstrate stimulating effects of high arginine concentrations in the cell media (up to the 8‐fold arginine blood concentration) on the proliferative activity and cytokine secretion of feline T cells . Importantly, in the study of Rutherfurd‐Markwick et al, a low‐protein diet (22.7% in dry matter) was offered and only a single dose of arginine (1.9% in dry matter) was tested.…”

“…2 In addition, an in vitro study could also demonstrate stimulating effects of high arginine concentrations in the cell media (up to the 8-fold arginine blood concentration) on the proliferative activity and cytokine secretion of feline T cells. 3 Importantly, in the study of Rutherfurd-Markwick et al, 2 a low-protein diet (22.7% in dry matter) was offered and only a single dose of arginine (1.9% in dry matter) was tested. In the present study, markedly higher protein (and arginine) intakes were evaluated in cats.…”

“…Supplementation of arginine to a low‐protein diet increases the proliferative and phagocytic activity of feline leukocytes . Cytokine secretion and proliferative activity of the feline T‐cell line MYA‐1 are enhanced by high doses of arginine in the cell media …”

Diet Alters Serum Metabolomic Profiling in the Mouse Model of Chronic Chagas Cardiomyopathy

“…The levels of many essential and nonessential amino acids were significantly reduced in infected mice compared to uninfected groups. It is well known that amino acids play a major role in regulating the immune system, nutritional status, and energy homeostasis [23,31]. Leucine, isoleucine, and valine are the branched chain aa's that influences immune responses which were significantly decreased in infected mice.…”

“…Interestingly, the levels of lysine and threonine were significantly increased in infected HFD-fed mice compared to uninfected HFD-fed mice and infected RD-fed mice (Figure 3(b)). Both lysine and threonine are essential immune modulators [23]. Nonessential amino acid profiling also differed between infected and uninfected, and between RD and HFD diets (Figure 3(a)).…”