Glycan-Controlled Human PD-1 Variants Displaying Broad-Spectrum High Binding to PD-1 Ligands Potentiate T Cell.

Although therapeutic immunoglobulin G (IgG) antibodies that regulate the activity of immune checkpoints bring innovation to the field of immuno-oncology, they are still limited in their efficiency to infiltrate the tumor microenvironment due to their large molecular size (150 kDa) and the necessity of additional engineering works to ablate effector functions for antibodies targeting immune cells. To address these issues, the human PD-1 (hPD-1) ectodomain, a small protein moiety of 14-17 kDa, has been considered as a therapeutic agent. Here, we used bacterial display-based high-throughput directed evolution to successfully isolate glycan-controlled (aglycosylated or only single-N-linked glycosylated) human PD-1 variants exhibiting over 1000-fold increased hPD-L1 binding affinity compared to that of wild-type hPD-1. The resulting hPD-1 variants, aglycosylated JYQ12 and JYQ12-2 with a single-N-linked glycan chain, showed exceptionally high binding affinity to hPD-L1 and very high affinity to both hPD-L2 and mPD-L1. Moreover, the JYQ12-2 efficiently potentiated the proliferation of human T cells. hPD-1 variants with significantly improved binding affinities for hPD-1 ligands could be used as effective therapeutics or diagnostics that can be differentiated from large-sized IgG antibody-based molecules.

Engineered human FcγRIIa fusion: A novel strategy to extend serum half-life of therapeutic proteins.

The immunoglobulin G (IgG) molecule has a long circulating serum half-life (~3 weeks) through pH- dependent FcRn binding-mediated recycling. To hijack the intracellular trafficking and recycling mechanism of IgG as a way to extend serum persistence of non-antibody therapeutic proteins, we have evolved the ectodomain of a low-affinity human FcγRIIa for enhanced binding to the lower hinge and upper CH2 region of IgG, which is very far from the FcRn binding site (CH2-CH3 interface). High-throughput library screening enabled isolation of an FcγRIIa variant (2A45.1) with 32-fold increased binding affinity to human IgG1 Fc (equilibrium dissociation constant: 9.04 × 10-7 M for wild type FcγRIIa and 2.82 × 10-8 M for 2A45.1) and significantly improved affinity to mouse serum IgG compared to wild type human FcγRIIa. The in vivo pharmacokinetic profile of PD-L1 fused with engineered FcγRIIa (PD-L1-2A45.1) was compared with that of PD-L1 fused with wild type FcγRIIa (PD-L1-wild type FcγRIIa) and human PD-L1 in mice. PD-L1-2A45.1 showed 11.7- and 9.7-fold prolonged circulating half-life (t1/2 ) compared to PD-L1 when administered intravenously and intraperitoneally, respectively. In addition, the AUCinf of PD-L1-2A45.1 was two-fold higher compared to that of PD-L1-wild type FcγRIIa. These results demonstrate that engineered FcγRIIa fusion offers a novel and successful strategy for prolonging serum half-life of therapeutic proteins.

The long-term effects of the health coaching self-management program for nursing-home residents.

BACKGROUND AND AIMS: Little is known about whether a self-management program for nursing-home residents (NHR) with cognitive impairment is likely to have an impact on the care of this growing population. This study aimed to evaluate the effects of the health-coaching self-management program for NHR (HCSMP-NHR) on 1) self-efficacy and goal attainment scaling (GAS), 2) health status and quality of life (QoL) among older people, including those with cognitive impairment, in Korean nursing homes. METHODS: This was a cluster-randomized controlled trial. Participants in the intervention group (n=43, mean age =80.91±7.65 years) received the HCSMP-NHR intervention, composed of group health education and individual coaching, for 8 weeks. Conventional care was provided to the conventional group (n=47, mean age =80.19±7.53 years) during the same period. The effects of the HCSMP-NHR were measured three times: at baseline, week 9, and week 20. RESULTS: The intervention group showed better results for self-efficacy (P=0.007), health distress (P=0.007), depression (P<0.001), and QoL (P=0.04) at week 9. Mean GAS score of the intervention group gradually increased from -0.38 to 0.74. The time × group interaction showed that the intervention group had significant improvements in QoL (P=0.047), and significant reductions in health distress (P=0.016) and depression (P<0.001), while showing no deterioration in shortness of breath (P<0.001). CONCLUSION: Our study findings indicate that the HCSMP-NHR improved self-efficacy and GAS and enhanced the health status and QoL of NHR with chronic conditions who also had mild-to-moderate cognitive impairment. Moreover, these effects were successfully maintained over the 5 months of the trial. Further research is needed to establish the optimum intervention period and to assess the possibility of nationwide implementation of the HCSMP-NHR.

Facilitators and barriers to self-management of nursing home residents: perspectives of health-care professionals in Korean nursing homes.

PURPOSE: To explore facilitators and barriers to self-management from the viewpoint of staff taking care of nursing home (NH) residents with chronic diseases in South Korea. PATIENTS AND METHODS: A qualitative content analysis was done using the focus group interview method. A total of 23 health-care professionals (16 registered nurses and 7 social workers) were interviewed from three urban NHs, each with more than 100 beds. RESULTS: Five facilitators were identified: grouping the residents; the resident's awareness of his/her current health status; the willingness of residents to engage in self-management; residence in the facility; and support from the staff. Additionally, seven barriers were identified: deterioration of the resident's health; the dependency expectations of the resident; hesitation in asking for help; difference in expectations between the staff and the resident's family; insufficient staffing and time; lack of standardized guidelines; and conservative tendencies of the staff due to rigid policies. CONCLUSION: The findings of this study can help health-care professionals recognize the factors that influence self-management and provide direction for registered nurses and other health professionals involved in supporting self-management programs for NH residents.

Bio-based production of monomers and polymers by metabolically engineered microorganisms.

Recent metabolic engineering strategies for bio-based production of monomers and polymers are reviewed. In the case of monomers, we describe strategies for producing polyamide precursors, namely diamines (putrescine, cadaverine, 1,6-diaminohexane), dicarboxylic acids (succinic, glutaric, adipic, and sebacic acids), and ω-amino acids (γ-aminobutyric, 5-aminovaleric, and 6-aminocaproic acids). Also, strategies for producing diols (monoethylene glycol, 1,3-propanediol, and 1,4-butanediol) and hydroxy acids (3-hydroxypropionic and 4-hydroxybutyric acids) used for polyesters are reviewed. Furthermore, we review strategies for producing aromatic monomers, including styrene, p-hydroxystyrene, p-hydroxybenzoic acid, and phenol, and propose pathways to aromatic polyurethane precursors. Finally, in vivo production of polyhydroxyalkanoates and recombinant structural proteins having interesting applications are showcased.