Evaluation of bupivacaine liposome injectable suspension efficacy in single-use vials over five days of multiple use.

OBJECTIVE: To test the anesthetic effect of a bupivacaine liposome injectable suspension (BLIS), used in a multiple-dose manner for up to 5 consecutive days. STUDY DESIGN: Prospective, randomized, experimental study. ANIMALS: A total of 30 male and female Sprague-Dawley rats (Rattus norvegicus), aged 97 (75-130) days and weighing 337.2 (219.6-465.9) g, mean (range). METHODS: Rats were assigned to one of five BLIS vial groups, in which drug was administered from a newly opened vial or 1, 2, 3 and 4 days after the vial was opened. The vials were refrigerated between uses. A 14 gauge needle attached to an injection plug was used to puncture each vial once and was not removed; BLIS was withdrawn from the injection plug in a multiple-dose fashion. A dose rate of 0.4 mL kg-1 was administered subcutaneously into the left pelvic limb paw. Antinociception was evaluated using a paw pressure test on both injected and uninjected paws before (time 0, baseline) and 1, 24, 48 and 72 hours after injection. RESULTS: Age of BLIS vial had no significant effect on anesthetic efficacy (p = 0.97). Across all groups, paw withdrawal latency averaged 5.23 ± 0.24 seconds at baseline (before BLIS injection), increased to 16.45 ± 0.65 seconds at 1 hour after BLIS injection, declined to 7.50 ± 0.76 seconds at 24 hours after BLIS injection, and further declined thereafter (p < 0.001). There was no significant change in paw withdrawal latency in the uninjected paw over time. CONCLUSIONS AND CLINICAL RELEVANCE: BLIS single-use vials retained efficacy when used up to 5 days in a multiple-dose fashion. Because anesthetic effects declined substantially after 24 hours, multimodal pain management remains important for providing analgesia care.

Timing is everything: impact of development, ageing and circadian rhythm on macrophage functions in urinary tract infections.

The bladder supports a diversity of macrophage populations with functional roles related to homeostasis and host defense, including clearance of cell debris from tissue, immune surveillance, and inflammatory responses. This review examines these roles with particular attention given to macrophage origins, differentiation, recruitment, and engagement in host defense against urinary tract infections (UTIs), where these cells recognize uropathogens through a combination of receptor-mediated responses. Time is an important variable that is often overlooked in many clinical and biological studies, including in relation to macrophages and UTIs. Given that ageing is a significant factor in urinary tract infection pathogenesis and macrophages have been shown to harbor their own circadian system, this review also explores the influence of age on macrophage functions and the role of diurnal variations in macrophage functions in host defense and inflammation during UTIs. We provide a conceptual framework for future studies that address these key knowledge gaps.

TNF-α enhances Th9 cell differentiation and antitumor immunity via TNFR2-dependent pathways.

Tumor specific Th9 cells are potential effector cells for adoptive therapy of human cancers. TNF family members OX40L, TL1A and GITRL have been shown to promote the induction of Th9 cells and antitumor immunity. However, the role of TNF-α, the prototype of the TNF superfamily cytokines, in Th9 cell differentiation and their antitumor efficacy is not defined. Here, we showed that TNF-α potently promoted naïve CD4+ T cells to differentiate into Th9 cells in vitro. Furthermore, the addition of TNF-α during Th9 cell differentiation increased T cell survival and proliferation. More importantly, the adoptive transfer of TNF-α-treated Th9 cells induced more potent antitumor effects than regular Th9 cells in mouse tumor model. TNF-α signals via two cell surface receptors, TNFR1 and TNFR2. Mechanistic studies revealed that TNF-α drove Th9 cell differentiation through TNFR2 but not TNFR1. In addition, under Th9 polarizing condition, TNF-α activated STAT5 and NF-κB pathways in T cells in a TNFR2-dependent manner. Inhibition of STAT5 and NF-κB pathways by their specific inhibitors impaired TNF-α-induced Th9 cell differentiation. Our results identified TNF-α as a new powerful inducer of Th9 cells and clarified the molecular mechanisms underlying TNF-α-induced Th9 cell differentiation.

IL-33 drives the antitumor effects of dendritic cells via the induction of Tc9 cells.

Dendritic cell (DC) tumor vaccines exert their antitumor effects through the induction of effector T cells. We recently identified Tc9 cells as a new potent antitumor effector T cell subset. However, approaches to direct DCs to preferably prime antitumor Tc9 cells should be further exploited. Here, we demonstrate that the addition of interleukin (IL)-33 potently promotes the induction of Tc9 cells by DCs in vitro and in vivo. IL-33 treatment also drives the cytotoxic activities of DC-induced Tc9 cells. Notably, IL-33 treatment enhances cell survival and proliferation of DC-primed CD8+ T cells. More importantly, the addition of IL-33 during in vitro priming of tumor-specific Tc9 cells by DCs increases the antitumor capability of Tc9 cells. Mechanistic studies demonstrated that IL-33 treatment inhibits exhaustive CD8+ T cell differentiation by inhibiting PD-1 and 2B4 expression and increasing IL-2 and CD127 (IL-7 receptor-α, IL-7Rα) expression in CD8+ T cells. Finally, the addition of IL-33 further promotes the therapeutic efficacy of DC-based tumor vaccines in the OT-I mouse model. Our study demonstrates the important role of IL-33 in DC-induced Tc9 cell differentiation and antitumor immunity and may have important clinical implications.

Interleukin-33 Contributes to the Induction of Th9 Cells and Antitumor Efficacy by Dectin-1-Activated Dendritic Cells.

We recently discovered that dectin-1-activated dendritic cells (DCs) drive potent T helper (Th) 9 cell responses and antitumor immunity. However, the underlying mechanisms need to be further defined. The cytokine microenvironment is critical for Th cell differentiation. Here, we show that dectin-1 activation enhances interleukin (IL)-33 expression in DCs. We found that blocking IL-33/ST2 inhibits dectin-1-activated DC-induced Th9 cell differentiation. More importantly, the addition of IL-33 further promotes Th9 cell priming and antitumor efficacy induced by dectin-1-activated DCs. Mechanistically, in addition to the promotion of Th9 and Th1 cells, dectin-1-activated DCs combined with IL-33 abolish the activity of IL-33 in the induction of regulatory T cells. Furthermore, the combined treatment of dectin-1-activated DCs and IL-33 increases the frequencies of CD4+ T cells by fostering their proliferation and inhibiting their exhaustive differentiation. Thus, our results demonstrate the important role of IL-33 in dectin-1-activated DC-induced Th9 cell differentiation and antitumor efficacy, and suggest that the combination of dectin-1-activated DCs and IL-33 may present a new effective modality of DC-based vaccines in tumor immunotherapy.