Recent progress on chimeric antigen receptor (CAR)-NK cells has shown promising results in treating CD19-positive lymphoid tumors with minimal toxicities [including graft versus host disease (GvHD) and cytokine release syndrome (CRS) in clinical trials. Nevertheless, the use of CAR-NK cells in combating viral infections has not yet been fully explored. Previous studies have shown that CAR-NK cells expressing S309 single-chain fragment variable (scFv), hereinafter S309-CAR-NK cells, can bind to SARS-CoV-2 wildtype pseudotyped virus (PV) and effectively kill cells expressing wild-type spike protein in vitro . In this study, we further demonstrate that the S309-CAR-NK cells can bind to different SARS-CoV-2 variants, including the B.1.617.2 (Delta), B.1.621 (Mu), and B.1.1.529 (Omicron) variants in vitro . We also show that S309-CAR-NK cells reduce virus loads in the NOD/SCID gamma (NSG) mice expressing the human angiotensin-converting enzyme 2 (hACE2) receptor challenged with SARS-CoV-2 wild-type (strain USA/WA1/2020). Our study demonstrates the potential use of S309-CAR-NK cells for inhibiting infection by SARS-CoV-2 and for the potential treatment of COVID-19 patients unresponsive to otherwise currently available therapeutics. IMPORTANCE: Chimeric antigen receptor (CAR)-NK cells can be “off-the-shelf” products that treat various diseases, including cancer, infections, and autoimmune diseases. In this study, we engineered natural killer (NK) cells to express S309 single-chain fragment variable (scFv), to target the Spike protein of SARS-CoV-2, hereinafter S309-CAR-NK cells. Our study shows that S309-CAR-NK cells are effective against different SARS-CoV-2 variants, including the B.1.617.2 (Delta), B.1.621 (Mu), and B.1.1.529 (Omicron) variants. The S309-CAR-NK cells can (i) directly bind to SARS-CoV-2 pseudotyped virus (PV), (ii) competitively bind to SARS-CoV-2 PV with 293T cells expressing the human angiotensin-converting enzyme 2 (hACE2) receptor (293T-hACE2 cells), (iii) specifically target and lyse A549 cells expressing the spike protein, and (iv) significantly reduce the viral loads of SARS-CoV-2 wild-type (strain USA/WA1/2020) in the lungs of NOD/SCID gamma (NSG) mice expressing hACE2 (hACE2-NSG mice). Altogether, the current study demonstrates the potential use of S309-CAR-NK immunotherapy as an alternative treatment for COVID-19 patients.

This study assessed the meat quality of Sika deer (Cervus nippon) from various age and sex groups using the longissimus dorsi (LD) muscle. Samples from different age groups (2, 3, and 4 years old) were analyzed for various parameters. The results show that, with increasing age, there is a decrease in moisture and drip loss (p < 0.05), alongside increases in ash, protein, fat, and cooking loss (p < 0.05). Female deer showed an increase in tenderness (p < 0.05), whereas males generally had a higher amino acid content (p < 0.05). Interestingly, 2-year-old female Sika deer had more saturated fatty acids (p < 0.05), while 3- and 4-year-old females had more unsaturated fatty acids compared to age-matched males (p < 0.05). Notably, 3-year-olds had higher levels of monounsaturated and polyunsaturated fatty acids in both the male and female groups (p < 0.05). Overall, this study provides the first comprehensive evidence that Sika deer meat is a nutritious source of lean protein. Notably, meat from 3-year-old Sika deer, regardless of sex, contains higher nutrient levels and is more tender compared to meat from deer of other ages. Additionally, meat from females tends to be more tender than that from males.

Objective: This study aimed to examine the impact of cupric citrate on broilers and compare it with the copper sulfate groups and a control group.Methods: A total of 360 1-day-old Ross 308 broilers were randomly assigned into 5 groups, each with 6 replicates of 12 broilers per treatment. The control group was fed a basal diet without any copper supplementation. In contrast, the other groups received basal diets supplemented with either 50 mg/kg (CS-50) or 100 mg/kg (CS-100) of copper in the form of copper sulfate, or 50 mg/kg (CC-50) or 100 mg/kg (CC-100) of copper in the form of cupric citrate, for a period of 42 days.Results: The results showed that copper supplementation affected the average daily gain (ADG) from day 1 to 21 (p = 0.026) and day 1 to 42 (p = 0.025) in a source-dependent manner. Copper source also influenced the energy digestibility (p = 0.004), with the CC-100 being the most effective treatment. Notably, birds in the CC-100 groups had significantly reduced concentrations of Escherichia coli (p<0.05) in the cecum, and the Lactobacillus in the ileum, compared to the control group. Dietary copper supplementation also increased the pH in the duodenum (p<0.05) irrespective of the sources and levels. In addition, the source of copper affected the activities of ceruloplasmin (p = 0.014) and CuZn superoxide dismutase (p = 0.025) in the serum, with the CC-100 group showing the highest levels of both enzymes.Conclusion: Copper supplementation generally improves the growth, nutrient utilization, intestinal microflora, gastrointestinal pH, and antioxidant defences of broilers. Moreover, cupric citrate is as effective as copper sulfate even at equal or lower concentrations.

This study examined the effects of dietary crude protein (CP: 18%, 15%) and crude fat (EE: 8%, 4%) levels, and their interactions, on growth performance, nutrient digestibility, serum indices, and rectal fecal microbiota in sika deer fawns during early wintering. A two-month 2 × 2 factorial experiment was conducted using 32 healthy five-month-old male fawns randomly assigned to four groups: P18E8 (18% CP, 8% EE), P18E4 (18% CP, 4% EE), P15E8 (15% CP, 8% EE), and P15E4 (15% CP, 4% EE). The P18E4 group showed the highest total weight gain and average daily gain (p < 0.05), along with greater apparent digestibility of dry matter, crude protein, calcium, and fiber fractions (p < 0.05). Serum urea content was significantly lower in this group, indicating improved nitrogen utilization (p < 0.05). Dominant fecal microbiota at the phylum level across all groups included Firmicutes_A and Bacteroidota, with the P18E4 group showing a unique genus composition within Bacteroidota, known for enhancing fiber digestion. In summary, a diet with 18% CP and 4% EE optimized growth performance, nutrient digestibility, and gut microbiota composition, providing a strategy for improving the health and productivity of sika deer fawns during overwintering.

This study evaluated the effects of dietary lysine supplementation in low-protein diets on nutrient digestibility, nitrogen metabolism, growth performance, serum biomarkers, and pelt quality in female blue foxes (Alopex lagopus) during the fur-growing period. A total of 105 18-week-old female blue foxes were randomly assigned to seven groups (n = 15 per group). The control group received a standard-protein diet (28% dry matter, DM), while six experimental groups were fed low-protein diets (26% DM) supplemented with 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% lysine, corresponding to total lysine levels of 0.75%, 0.95%, 1.15%, 1.35%, 1.55%, and 1.75% DM, respectively. Lysine supplementation at 1.35% and 1.55% DM significantly improved the digestibility of ether extract and amino acids, including aspartic acid, glycine, methionine, isoleucine, and tyrosine (p < 0.05). Nitrogen retention increased accordingly, indicating enhanced dietary utilization (p < 0.05). Daily weight gain, particularly from day 15 to day 30, was significantly higher in 1.15–1.55% lysine groups compared to low-lysine groups (p < 0.05), achieving growth performance comparable to the control (p > 0.05). Serum total protein and albumin concentration were significantly improved with increasing lysine levels in low-protein groups (p < 0.01), aligning with those of the control group (p > 0.05). Furthermore, high lysine supplementation significantly improved pelt quality, as evidenced by the increased underfur length and decreased guard hair/underfur in 1.35–1.75% DM (p < 0.05). These findings suggest that lysine supplementation in low-protein diets supports nutrient utilization, growth performance, and metabolic health status while reducing dietary protein content. The optimal dietary lysine range is 1.15% to 1.55% DM (corresponding to 0.4% to 0.8% in air-dry basis), with 1.35% DM (corresponding to 0.6% in air-dry basis) identified as the most suitable level for balancing growth, nitrogen excretion, and pelt quality in fur-growing female blue foxes.