STAT3 Gain-of-Function Mutations Underlie Deficiency in Human Nonclassical CD16+ Monocytes and CD141+ Dendritic Cells.

Genetic analysis of human inborn errors of immunity has defined the contribution of specific cell populations and molecular pathways in the host defense against infection. The STAT family of transcription factors orchestrate hematopoietic cell differentiation. Patients with de novo activating mutations of STAT3 present with multiorgan autoimmunity, lymphoproliferation, and recurrent infections. We conducted a detailed characterization of the blood monocyte and dendritic cell (DC) subsets in patients with gain-of-function (GOF) mutations across the gene. We found a selective deficiency in circulating nonclassical CD16+ and intermediate CD16+CD14+ monocytes and a significant increase in the percentage of classical CD14+ monocytes. This suggests a role for STAT3 in the transition of classical CD14+ monocytes into the CD16+ nonclassical subset. Developmentally, ex vivo-isolated STAT3GOF CD14+ monocytes fail to differentiate into CD1a+ monocyte-derived DCs. Moreover, patients with STAT3GOF mutations display reduced circulating CD34+ hematopoietic progenitors and frequency of myeloid DCs. Specifically, we observed a reduction in the CD141+ DC population, with no difference in the frequencies of CD1c+ and plasmacytoid DCs. CD34+ hematopoietic progenitor cells from patients were found to differentiate into CD1c+ DCs, but failed to differentiate into CD141+ DCs indicating an intrinsic role for STAT3 in this process. STAT3GOF-differentiated DCs produced lower amounts of CCL22 than healthy DCs, which could further explain some of the patient pathological phenotypes. Thus, our findings provide evidence that, in humans, STAT3 serves to regulate development and differentiation of nonclassical CD16+ monocytes and a subset of myeloid DCs.

CD5 expression by dendritic cells directs T cell immunity and sustains immunotherapy responses.

The induction of proinflammatory T cells by dendritic cell (DC) subtypes is critical for antitumor responses and effective immune checkpoint blockade (ICB) therapy. Here, we show that human CD1c+CD5+ DCs are reduced in melanoma-affected lymph nodes, with CD5 expression on DCs correlating with patient survival. Activating CD5 on DCs enhanced T cell priming and improved survival after ICB therapy. CD5+ DC numbers increased during ICB therapy, and low interleukin-6 (IL-6) concentrations promoted their de novo differentiation. Mechanistically, CD5 expression by DCs was required to generate optimally protective CD5hi T helper and CD8+ T cells; further, deletion of CD5 from T cells dampened tumor elimination in response to ICB therapy in vivo. Thus, CD5+ DCs are an essential component of optimal ICB therapy.

Communication via motion - Suitability of automated vehicle movements to negotiate the right of way in road bottleneck scenarios.

The introduction of automated vehicles (AVs) into urban areas initially leads to mixed traffic, consisting of AVs, human drivers, and vulnerable road users. Since the AV's passenger is no longer actively involved in the driving task, there may be changes in the interaction between AVs and surrounding human road users. Therefore, it is essential for an AV to behave in a comprehensible manner in order to maintain or even enhance traffic efficiency and traffic safety. This work investigates the interaction of an AV and a simultaneously oncoming human driver at road bottlenecks due to double-parked vehicles on both sides of the road. Based on findings derived from AV-pedestrian interaction, comfort limits in terms of driving dynamics, and traffic observations, we designed nine AV movements to either yield the right of way or to insist on it by varying the AV's speed (maintain speed, one-step deceleration, two-step deceleration) and its lateral offset (no offset, close offset, distant offset). The different vehicle movements were evaluated with 34 participants in a driving simulator study. The results show participants' shorter passing times, fewer crashes, and significantly higher ratings of the AV's communication if the AV movement contained a lateral offset. In addition to the regular encounters, we analyzed the controllability of an automation failure and its aftereffect on participants' trust in AVs. The experience of the automation failure reduced the trust rating significantly. From the results we conclude that the AV should communicate the right of way not only via speed adjustments but also via the performance of a lateral offset to enhance traffic efficiency and safety. Moreover, a change in the AV's maneuver due to an automation failure must be avoided since it is not controllable by the human driver.

The TAT Protein Transduction Domain as an Intra-Articular Drug Delivery Technology.

OBJECTIVE: Intra-articular drug delivery holds great promise for the treatment of joint diseases such as osteoarthritis. The objective of this study was to evaluate the TAT peptide transduction domain (TAT-PTD) as a potential intra-articular drug delivery technology for synovial joints. DESIGN: Experiments examined the ability of TAT conjugates to associate with primary chondrocytes and alter cellular function both in vitro and in vivo. Further experiments examined the ability of the TAT-PTD to bind to human osteoarthritic cartilage. RESULTS: The results show that the TAT-PTD associates with chondrocytes, is capable of delivering siRNA for chondrocyte gene knockdown, and that the recombinant enzyme TAT-Cre is capable of inducing in vivo genetic recombination within the knee joint in a reporter mouse model. Last, binding studies show that osteoarthritic cartilage preferentially uptakes the TAT-PTD from solution. CONCLUSIONS: The results suggest that the TAT-PTD is a promising delivery strategy for intra-articular therapeutics.