Preparation, characterization and application of anti-human OX40 ligand (OX40L) monoclonal antibodies and establishment of a sandwich ELISA for autoimmune diseases detection

Establishment of a novel double-monoclonal antibody sandwich enzyme-linked immunosorbent assay (ELISA): tool for human B7-H4 detection in autoimmune diseases

B7-H4, one of the immunoregulatory proteins, plays an inhibitory role by inhibiting T cell proliferation and cytokine production. Nevertheless, the significance of soluble B7-H4 (sB7-H4) in autoimmune diseases is unclear. In our study, we developed two novel mouse anti-human B7-H4 monoclonal antibodies (mAbs) (clones 8D4 and 7E1) with utilities for flow cytometry, immunoblotting and immunofluorescence. We characterized 7E1 as a functional antibody with antagonistic activity, which could promote T cell proliferation and regulate cytokine production. Furthermore, based on the different epitope specificities, we established a novel enzyme-linked immunosorbent assay (ELISA) which could detect sB7-H4 sensitively and specifically. Using this ELISA kit, sB7-H4 was observed in a high proportion of autoimmune diseases patients. We found that the levels of sB7-H4 were significantly higher in patients with systemic lupus erythematosus (SLE), type I diabetes (T1D) and Graves' disease (GD). Together, sB7-H4 in human serum is regarded not only as a regulator of T cell activation but may also be a diagnostic marker of autoimmune diseases.

Development of a robust reporter gene assay for measuring the bioactivity of OX40-targeted therapeutic antibodies

OX40 plays a prominent role in the onset and development of solid tumors, and OX40-targeted monoclonal antibodies (mAbs) have entered clinical trials for various tumors. Bioactivity determination of therapeutic mAbs is of great significance in product quality, however, mechanism of action-based bioassays to determine the bioactivity of anti-OX40 mAbs is still lacking. Here, we established a reporter gene assay system based on two cell lines, namely Jurkat-OX40-NFκB-Luc which stably expresses NFκB-controlled luciferase, and Raji cells which inherently express FcγRs. In the model, FcγRs on Raji cells could crosslink the Fc of anti-OX40 mAbs, which leads to the further crosslinking between Fab of anti-OX40 mAbs and OX40 on Jurkat-OX40-NFκB-Luc cells. OX40 crosslinking could activate Jurkat-OX40-NFκB-Luc cells, and induce the expression of NFκB-controlled luciferase, the extent of which could reflect the bioactivity of anti-OX40 mAbs in a dose-dependent manner. After the optimization of various assay conditions, the validation of the cell-based bioassay showed good assay performance characteristics, including specificity, accuracy, precision, linearity, and stability. This innovative assay that is based on the OX40-NFκB pathway can be a powerful pool to measure the bioactivity of OX40-targeted mAbs.

Association of TNFSF4 rs1234315, rs2205960 polymorphisms and systemic lupus erythematosus susceptibility: a meta-analysis

BACKGROUND

The aim of this study was to explore the association between tumor necrosis factor superfamily number 4 (TNFSF4) rs1234315, rs2205960 polymorphisms and systemic lupus erythematosus (SLE) susceptibility.

METHODS

A meta-analysis was performed on the association between rs1234315 and rs2205960 polymorphisms and SLE by allelic contrast, additive model, recessive model and dominant model.

RESULTS

Regarding rs1234315 polymorphism, a total of five studies were included (6575 cases, 14,798 controls). Meta-analysis showed significant associations between the T allele and SLE in overall subjects and Asians (OR = 1.310, 95%CI: 1.104-1.553, p = 0.002; OR = 1.458, 95%CI: 1.328-1.602, p < 0.001). With respect to the rs2205960 polymorphism, significant associations between the T allele and SLE were found in all subjects (OR = 1.333, 95%CI: 1.254-1.418, p < 0.001), Asians (OR = 1.407, 95%CI: 1.345-1.471, p < 0.001) and Europeans (OR = 1.254, 95%CI: 1.185-1.328, p < 0.001). Results also showed significant associations between the additive model and SLE in all subjects and Asians (OR = 1.934, 95%CI: 1.500-2.494, p < 0.001; OR = 1.882, 95%CI: 1.318-2.689, p = 0.001). Furthermore, we detected significant associations between the dominant model and SLE in all subjects and Asians (OR = 1.421, 95%CI: 1.239-1.629, p < 0.001; OR = 1.297, 95%CI: 1.083-1.555, p = 0.005). Significant associations were found between the recessive model and SLE in overall subjects and Asians (OR = 1.677, 95%CI: 1.312-2.144, p < 0.001; OR = 1.751, 95%CI: 1.235-2.483, p = 0.002).

CONCLUSION

The present study suggested that TNFSF4 rs1234315 and rs2205960 polymorphisms were associated with SLE susceptibility.