Effects of Soluble Tumor Necrosis Factor (TNF) on Antibody-Dependent Cellular Cytotoxicity of Therapeutic anti-TNF-α Antibody

Role of tumor necrosis factor-alpha in the central nervous system: a focus on autoimmune disorders

Tumor necrosis factor-alpha (TNF-α) is a pleiotropic immune cytokine that belongs to the TNF superfamily of receptor ligands. The cytokine exists as either a transmembrane or a soluble molecule, and targets two distinct receptors, TNF-α receptor 1 (TNFR1) and TNF-α receptor 2 (TNFR2), which activate different signaling cascades and downstream genes. TNF-α cellular responses depend on its molecular form, targeted receptor, and concentration levels. TNF-α plays a multifaceted role in normal physiology that is highly relevant to human health and disease. In the central nervous system (CNS), this cytokine regulates homeostatic functions, such as neurogenesis, myelination, blood-brain barrier permeability and synaptic plasticity. However, it can also potentiate neuronal excitotoxicity and CNS inflammation. The pleiotropism of TNF-α and its various roles in the CNS, whether homeostatic or deleterious, only emphasizes the functional complexity of this cytokine. Anti-TNF-α therapy has demonstrated effectiveness in treating various autoimmune inflammatory diseases and has emerged as a significant treatment option for CNS autoimmune diseases. Nevertheless, it is crucial to recognize that the effects of this therapeutic target are diverse and complex. Contrary to initial expectations, anti-TNF-α therapy has been found to have detrimental effects in multiple sclerosis. This article focuses on describing the various roles, both physiological and pathological, of TNF-α in the CNS. Additionally, it discusses the specific disease processes that are dependent or regulated by TNF-α and the rationale of its use as a therapeutic target.

Establishment of Cell-Based Assay System for Evaluating Cytotoxic Activity Modulated by the Blockade of PD-1 and PD-L1 Interactions with a Therapeutic Antibody

BACKGROUND

Therapeutic antibodies targeting the PD-1/PD-L1 immune checkpoint are widely used in cancer therapy and are under active further development. Historically, the antitumor activity of PD-1/PD-L1 immune checkpoint inhibitors has been evaluated using in vivo and ex vivo test methods; however, a simple in vitro assay method to evaluate antitumor activity accurately is needed for the efficient development of new therapeutic agents. In the present study, we attempted to establish a simple cell-based assay system to evaluate the modulating effect of PD-1/PD-L1 immune checkpoint inhibitors on cytotoxic activity.

METHODS

We established a new natural killer (NK) cell line stably transfected with the PD-1 and IL-2 genes and a new NK-sensitive target cell line stably transfected with the PD-L1 gene. Then, the assay system was established by co-cultivation of the established cell lines and measurement of the cytotoxic activities using the europium release assay. To confirm the performance of the established assay system, model therapeutic antibodies to block the PD-1/PD-L1 signal, nivolumab and atezolizumab were added to the co-culture system and the modulating effect on the cytotoxic activities were evaluated.

RESULTS

Nivolumab and atezolizumab clearly showed a modulating effect on cytotoxic activity in a dose-dependent manner in our assay system, whereas a human IgG isotype control antibody did not show any modulating effect on the assay system.

CONCLUSION

The newly established cell-based assay system can quantitatively evaluate the modulating effect of PD-1/PD-L1 immune checkpoint inhibitors by measuring cytotoxic activity, playing an important role in antitumor effects as innate immunity.

Differential efficacy of TNF inhibitors with or without the immunoglobulin fragment crystallizable (Fc) portion in rheumatoid arthritis: the ANSWER cohort study

Rheumatoid factor (RF) binds to the fragment crystallizable (Fc) portion of immunoglobulin. It could bind to the Fc portion of anti-TNF inhibitors (TNFi) and attenuate the clinical efficacy. We tried to determine whether the therapeutic efficacy of TNFi with Fc might be lower than that of TNFi without Fc in rheumatoid arthritis (RA) patients with high titres of RF. The Kansai Consortium for Well-being of Rheumatic Disease Patients (ANSWER) cohort is an observational multi-center registry of patients with RA in the Kansai district of Japan. RA patients treated with TNFi were included and divided into two groups based on the structural characteristics between TNFi with Fc (infliximab, adalimumab, golimumab, and etanercept) and TNFi without Fc (certolizumab pegol). Patients were classified into 4 groups according to RF titre quartiles. The sequential disease activity score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR) was compared by Mann-Whitney U test between TNFi with and without Fc in each RF titre group. Multiple linear regression analysis was used to analyze the effect of TNFi without Fc for the change of DAS28-ESR adjusted after potential confounders. A total of 705 RA patients were classified into four groups (RF¹; RF 0-15.0 IU/mL, RF²; 15.0-55.0, RF³; 55.0-166, RF⁴; 166-7555). In RF⁴, RA patients treated with TNFi without Fc had a significantly lower DAS28-ESR than those treated with TNFi with Fc [3.2 (2.3-4.2) vs. 2.7 (2.0-3.0)] after 12 months. This effect of TNFi without Fc for the change of DAS28-ESR after 12 months treatment retained in multivariate analysis in RF⁴. TNFi without Fc may be more efficacious than TNFi with Fc in RA patients with high RF titres.

Trypsinogen and chymotrypsinogen: potent anti-tumor agents

Introduction: Trypsinogen and chymotrypsinogen have been used clinically in tissue repair due to their ability to resolve inflammatory symptoms. Recently, novel evidence has supported the anti-tumourigenic potential of a mixture of trypsinogen and chymotrypsinogen.Areas covered: First, we analyze the structure of these proteases and the effects of pancreatic proteinases on tissue repair, inflammation and the immune system. Second, we summarize studies that provided evidence of the effects of pancreatic (pro)enzymes on tumor cells both in vitro and in vivo and some successful clinical applications of pancreatic (pro)enzymes. Finally, we study pancreatic (pro)enzymes potential molecular targets, such as the proteinase-activated receptors (PARs).Expert opinion: This novel therapy has been shown to have effective antitumor effects. Treatment with these (pro) enzymes sensitizes Cancer Stem Cells (CSCs) which may allow chemotherapy and radiotherapy to be more effective, which could positively affect the recovery of cancer patients.

Chitosan hydrogel encapsulated with LL-37 peptide promotes deep tissue injury healing in a mouse model

BACKGROUND

LL-37 peptide is a member of the human cathelicidin family, and has been shown to promote the healing of pressure ulcers. However, the low stability of this peptide within the wound environment limits its clinical use. Chitosan (CS) hydrogel is commonly used as a base material for wound dressing material.

METHODS

CS hydrogel (2.5% w/v) was encapsulated with LL-37. Cytotoxicity of the product was examined in cultured NIH3T3 fibroblasts. Effects on immune response was examined by measuring tumor necrosis factor-α (TNF-α) release from RAW 264.7 macrophages upon exposure to lipopolysaccharides. Antibacterial activity was assessed using Staphylococcus aureus. Potential effect on pressure ulcers was examined using a mouse model. Briefly, adult male C57BL/6 mice were subjected to skin pressure using magnets under a 12/12 h schedule for 21 days. Mice were randomized to receive naked LL-37 (20 μg), chitosan gel containing 20-μg LL-37 (LL-37/CS hydrogel) or hydrogel alone under the ulcer bed (n = 6). A group of mice receiving no intervention was also included as a control.

RESULTS

LL-37/CS hydrogel did not affect NIH3T3 cell viability. At a concentration of 1-5 μg/ml, LL-37/CS inhibited TNF-α release from macrophage. At 5 μg/ml, LL-37/CS inhibited the growth of Staphylococcus aureus. The area of the pressure ulcers was significantly lower in mice receiving LL-37/CS hydrogel in comparison to all other 3 groups on days 11 (84.24% ± 0.25%), 13 (56.22% ± 3.91%) and 15 (48.12% ± 0.28%). Histological examination on days 15 and 21 showed increased epithelial thickness and density of newly-formed capillary with naked LL-37 and more so with LL-37/CS. The expression of key macromolecules in the process of angiogenesis (i.e., hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor-A (VEGF-A)) in wound tissue was increased at both the mRNA and protein levels.

CONCLUSION

Chitosan hydrogel encapsulated with LL-37 is biocompatible and could promote the healing of pressure ulcers.