Thymic Stromal Lymphopoietin Induction Is Mediated by the Major Whey Proteins α-Lactalbumin and β-Lactoglobulin through the NF-κB Pathway in Immune Cells

A label-free photoelectrochemical immunosensor for detection of the milk allergen β-lactoglobulin based on Ag2S -sensitized spindle-shaped BiVO4/BiOBr heterojunction by an in situ growth method

Food allergies have become a nonnegligible food safety issue, and milk allergies are one of the most common food allergies, that has attracted large consumer attention. In this work, a novel label-free photoelectrochemical (PEC) immunosensor for the detection of the allergen β-lactoglobulin (β-LG) in dairy products was designed that used the specific recognition of allergen β-LG and antibodies in dairy products in combination with biosensing technology. Here, Ag₂S-sensitized spindle-shaped BiVO₄/BiOBr heterojunction was fixed on the surface of the ITO electrode as an excellent photoactive substrate and effectively improved the photocurrent responses and sensitivity. Thioglycolic acid (TGA) was used as a linker to immobilize the β-LG antibody on the surface of the electrode. The photocurrent was detected at different antigen concentrations, which realized the quantitative testing of β-LG. Under the optimal experimental conditions, the PEC immunosensor proved an ideal linear relationship ranging from 10 pg/mL to 100 ng/mL, with a low detection limit of 3.7 pg/mL. The designed immunosensor showed good stability, a wide linear range, high sensitivity and good reproducibility and could be used for the detection of actual samples. The PEC immunosensor had a strong ability to specifically recognize β-LG, which was not affected by other proteins in the milk without pretreatment. Meanwhile, the developed immunosensor provided a promising PEC detection platform and reference idea for the detection of other proteins in milk.

β-Lactoglobulin Influences Human Immunity and Promotes Cell Proliferation

β-Lactoglobulin (LG) is suspected to enhance or modulate human immune responses. Moreover, LG is also hypothesized to increase human cell proliferation. However, these potential functions of LG have not been directly or thoroughly addressed. In this study, we demonstrated that LG is a potent stimulator of cell proliferation using a hybridoma cell (a splenocyte fused with a myeloma cell) model. LG's ability to promote cell proliferation was lost when the protein is denatured. To further investigate the influence of LG's conformation on cell proliferation, we chemically modified LG by either carboxymethylation (CM) or acetylation and observed significantly reduced cell proliferation when the protein structure was altered. Furthermore, we proved that LG enhances cell proliferation via receptor-mediated membrane IgM receptor. These data indicated that nondenatured LG is the major component in milk that modulates cell proliferation. Collectively, our study showed that LG plays a key role in enhancing immune responses by promoting cell proliferation through IgM receptor.