Sensory neurons regulate stimulus-dependent humoral immunity in mouse models of bacterial infection and asthma.

Sensory neurons sense pathogenic infiltration to drive innate immune responses, but their role in humoral immunity is unclear. Here, using mouse models of Streptococcus pneumoniae infection and Alternaria alternata asthma, we show that sensory neurons are required for B cell recruitment and antibody production. In response to S. pneumoniae, sensory neuron depletion increases bacterial burden and reduces B cell numbers, IgG release, and neutrophil stimulation. Meanwhile, during A. alternata-induced airway inflammation, sensory neuron depletion decreases B cell population sizes, IgE levels, and asthmatic characteristics. Mechanistically, during bacterial infection, sensory neurons preferentially release vasoactive intestinal polypeptide (VIP). In response to asthma, sensory neurons release substance P. Administration of VIP into sensory neuron-depleted mice suppresses bacterial burden, while VIPR1 deficiency increases infection. Similarly, exogenous substance P delivery aggravates asthma in sensory neuron-depleted mice, while substance P deficiency ameliorates asthma. Our data, thus demonstrate that sensory neurons release select neuropeptides which target B cells dependent on the immunogen.

Antiviral capacity of the early CD8 T-cell response is predictive of natural control of SIV infection: Learning in vivo dynamics using ex vivo data.

While most individuals suffer progressive disease following HIV infection, a small fraction spontaneously controls the infection. Although CD8 T-cells have been implicated in this natural control, their mechanistic roles are yet to be established. Here, we combined mathematical modeling and analysis of previously published data from 16 SIV-infected macaques, of which 12 were natural controllers, to elucidate the role of CD8 T-cells in natural control. For each macaque, we considered, in addition to the canonical in vivo plasma viral load and SIV DNA data, longitudinal ex vivo measurements of the virus suppressive capacity of CD8 T-cells. Available mathematical models do not allow analysis of such combined in vivo-ex vivo datasets. We explicitly modeled the ex vivo assay, derived analytical approximations that link the ex vivo measurements with the in vivo effector function of CD8-T cells, and integrated them with an in vivo model of virus dynamics, thus developing a new learning framework that enabled the analysis. Our model fit the data well and estimated the recruitment rate and/or maximal killing rate of CD8 T-cells to be up to 2-fold higher in controllers than non-controllers (p = 0.013). Importantly, the cumulative suppressive capacity of CD8 T-cells over the first 4-6 weeks of infection was associated with virus control (Spearman's ρ = -0.51; p = 0.05). Thus, our analysis identified the early cumulative suppressive capacity of CD8 T-cells as a predictor of natural control. Furthermore, simulating a large virtual population, our model quantified the minimum capacity of this early CD8 T-cell response necessary for long-term control. Our study presents new, quantitative insights into the role of CD8 T-cells in the natural control of HIV infection and has implications for remission strategies.

Non-canonical IL-22 receptor signaling remodels the mucosal barrier during fungal immunosurveillance.

Mucosal barrier integrity is vital for homeostasis with commensal organisms while preventing pathogen invasion. We unexpectedly found that fungal-induced immunosurveillance enhances resistance to fungal outgrowth and tissue invasion by remodeling the oral mucosal epithelial barrier in mouse models of adult and neonatal Candida albicans colonization. Epithelial subset expansion and tissue remodeling were dependent on interleukin-22 (IL-22) and signal transducer and activator of transcription 3 (STAT3) signaling, through a non-canonical receptor complex composed of glycoprotein 130 (gp130) coupled with IL-22RA1 and IL-10RB. Immunosurveillance-induced epithelial remodeling was restricted to the oral mucosa, whereas barrier architecture was reset once fungal-specific immunity developed. Collectively, these findings identify fungal-induced transient mucosal remodeling as a critical determinant of resistance to mucosal fungal infection during early stages of microbial colonization.

Sensory neurons regulate stimulus-dependent humoral immunity.

Sensory neurons sense pathogenic infiltration, serving to inform immune coordination of host defense. However, sensory neuron-immune interactions have been predominantly shown to drive innate immune responses. Humoral memory, whether protective or destructive, is acquired early in life - as demonstrated by both early exposure to streptococci and allergic disease onset. Our study further defines the role of sensory neuron influence on humoral immunity in the lung. Using a murine model of Streptococcus pneumonia pre-exposure and infection and a model of allergic asthma, we show that sensory neurons are required for B-cell and plasma cell recruitment and antibody production. In response to S. pneumoniae, sensory neuron depletion resulted in a larger bacterial burden, reduced B-cell populations, IgG release and neutrophil stimulation. Conversely, sensory neuron depletion reduced B-cell populations, IgE and asthmatic characteristics during allergen-induced airway inflammation. The sensory neuron neuropeptide released within each model differed. With bacterial infection, vasoactive intestinal polypeptide (VIP) was preferentially released, whereas substance P was released in response to asthma. Administration of VIP into sensory neuron-depleted mice suppressed bacterial burden and increased IgG levels, while VIP1R deficiency increased susceptibility to bacterial infection. Sensory neuron-depleted mice treated with substance P increased IgE and asthma, while substance P genetic ablation resulted in blunted IgE, similar to sensory neuron-depleted asthmatic mice. These data demonstrate that the immunogen differentially stimulates sensory neurons to release specific neuropeptides which specifically target B-cells. Targeting sensory neurons may provide an alternate treatment pathway for diseases involved with insufficient and/or aggravated humoral immunity.

Diastereoselective and Scalable Synthesis of 6-(S)-Hydroxycannabidivarin.

The synthesis of 6-(S)-hydroxycannabidivarin was required to assess its biological activity in the treatment of neurological disorders. A novel and scalable synthesis has been developed where the key step involves a Friedel-Crafts alkylation of phloroglucinol with (1S,2R,5R)-2-hydroxy-2-methyl-5-(prop-1-en-2-yl)cyclohex-3-en-1-ylbenzoate. Careful optimization of the reaction conditions identified trifluoromethanesulfonic acid in isopropyl acetate as the best catalyst/solvent combination, providing optimum regioselectivity, diastereoselectivity, and yield for this step. This enabled the multigram synthesis of 6-(S)-hydroxycannabidivarin in 10 steps from S-(+)-carvone.

Pathogen recognition by sensory neurons: hypotheses on the specificity of sensory neuron signaling.

Sensory neurons cooperate with barrier tissues and resident immune cells to form a significant aspect of defensive strategies in concert with the immune system. This assembly of neuroimmune cellular units is exemplified across evolution from early metazoans to mammalian life. As such, sensory neurons possess the capability to detect pathogenic infiltrates at barrier surfaces. This capacity relies on mechanisms that unleash specific cell signaling, trafficking and defensive reflexes. These pathways exploit mechanisms to amplify and enhance the alerting response should pathogenic infiltration seep into other tissue compartments and/or systemic circulation. Here we explore two hypotheses: 1) that sensory neurons' potential cellular signaling pathways require the interaction of pathogen recognition receptors and ion channels specific to sensory neurons and; 2) mechanisms which amplify these sensing pathways require activation of multiple sensory neuron sites. Where possible, we provide references to other apt reviews which provide the reader more detail on specific aspects of the perspectives provided here.

Development and in vivo evaluation of fused benzazole analogs of anti-melanoma agent HA15.

Background: In line with our recent discovery of an efficient anticancer thiazolebenzenesulfonamide framework HA15 (1) based on a remarkable endoplasmic reticulum stress inducement mode of action, we report herein a series of innovative constrained HA15 analogs, featuring four types of bicylic derivatives. Results: The structure-activity relationship analysis, using a cell line assay, led us to identify a novel version of HA15: a new benzothiazole derivative (10b) exhibiting important anti-melanoma effect against sensitive and resistant melanoma cells. Meanwhile, compound 10b induced a significant tumor growth inhibition in vivo with no apparent signs of toxicity. Conclusion: These results consistently open new directions to improve and develop more powerful anticancer therapeutics harboring this type of fused framework.

Optimal Maturation of the SIV-Specific CD8+ T Cell Response after Primary Infection Is Associated with Natural Control of SIV: ANRS SIC Study.

Highly efficient CD8+ T cells are associated with natural HIV control, but it has remained unclear how these cells are generated and maintained. We have used a macaque model of spontaneous SIVmac251 control to monitor the development of efficient CD8+ T cell responses. Our results show that SIV-specific CD8+ T cells emerge during primary infection in all animals. The ability of CD8+ T cells to suppress SIV is suboptimal in the acute phase but increases progressively in controller macaques before the establishment of sustained low-level viremia. Controller macaques develop optimal memory-like SIV-specific CD8+ T cells early after infection. In contrast, a persistently skewed differentiation phenotype characterizes memory SIV-specific CD8+ T cells in non-controller macaques. Accordingly, the phenotype of SIV-specific CD8+ T cells defined early after infection appears to favor the development of protective immunity in controllers, whereas SIV-specific CD8+ T cells in non-controllers fail to gain antiviral potency, feasibly as a consequence of early defects imprinted in the memory pool.

Structure activity relationship and optimization of N-(3-(2-aminothiazol-4-yl)aryl)benzenesulfonamides as anti-cancer compounds against sensitive and resistant cells.

We recently described a new family of bioactive molecules with interesting anti-cancer activities: the N-(4-(3-aminophenyl)thiazol-2-yl)acetamides. The lead compound of the series (1) displays significant anti-proliferative and cytotoxic activities against a panel of cancer cell lines, either sensitive or resistant to standard treatments. This molecule also shows a good pharmacological profile and high in vivo potency towards mice xenografts, without signs of toxicity on the animals. In the present article, we disclose the structure-activity relationships of this lead compound, which have provided clear information about the replacement of the acetamide function and the substitution pattern of the benzenesulfonamide ring. An improved high-yielding synthetic procedure towards these compounds has also been developed. Our drug design resulted in potency enhancement of 1, our new optimized lead compound being 19. These findings are of great interest to further improve this scaffold for the development of future clinical candidates.

Metastatic Melanoma: Insights Into the Evolution of the Treatments and Future Challenges.

Melanoma is the deadliest form of skin cancer. While associated survival prognosis is good when diagnosed early, it dramatically drops when melanoma progresses into its metastatic form. Prior to 2011, the favored therapies include interleukin-2 and chemotherapies, regardless of their low efficiency and their toxicity. Following key biological findings, two new types of therapy have been approved. First, there are the targeted therapies, which rely on small molecule B-Raf and MEK inhibitors and allow the treatment of patients with B-Raf mutated melanoma. Second, there are the immunotherapies, with anti-CTLA-4 and anti-PD-1 antibodies that are used for patients harboring a B-Raf wild-type status. Both approaches have significantly improved patient survival, compared with alkylating agents, in the treatment of unresectable melanoma. Herein, we review the evolution of the treatment of melanoma starting from early discoveries to current therapies. A focus will be provided on drug discovery, synthesis, and mode of action of relevant drugs and the future directions of the domain to overcome the emergence of the resistance events.

Discovery and Optimization of N-(4-(3-Aminophenyl)thiazol-2-yl)acetamide as a Novel Scaffold Active against Sensitive and Resistant Cancer Cells.

Cancer is the second cause of deaths worldwide and is forecasted to affect more that 22 million people in 2020. Despite dramatic improvement in its care over the last two decades, the treatment of resistant forms of cancer is still an unmet challenge. Thus, innovative and efficient treatments are still needed. In this context, we report herein the synthesis and the evaluation of a new class of bioactive molecules belonging to the N-(4-(3-aminophenyl(thiazol-2-yl)acetamide family. Structure-activity relationships could be driven and resulted in the discovery of lead compound 6b. The latter display high in vitro potency against both sensitive and resistant cancer cell lines on three models: melanoma, pancreatic cancer, and chronic myeloid leukemia (CML). 6b leads to cell death by concomitant induction of apoptosis and autophagy, shows good pharmacokinetic properties, and demonstrates a significant reduction of tumor growth in vivo on A375 xenograft model in mice.

Compounds Triggering ER Stress Exert Anti-Melanoma Effects and Overcome BRAF Inhibitor Resistance.

We have discovered and developed a series of molecules (thiazole benzenesulfonamides). HA15, the lead compound of this series, displayed anti-cancerous activity on all melanoma cells tested, including cells isolated from patients and cells that developed resistance to BRAF inhibitors. Our molecule displayed activity against other liquid and solid tumors. HA15 also exhibited strong efficacy in xenograft mouse models with melanoma cells either sensitive or resistant to BRAF inhibitors. Transcriptomic, proteomic, and biochemical studies identified the chaperone BiP/GRP78/HSPA5 as the specific target of HA15 and demonstrated that the interaction increases ER stress, leading to melanoma cell death by concomitant induction of autophagic and apoptotic mechanisms.

Spatial phenotypic and genetic structure of threespine stickleback (Gasterosteus aculeatus) in a heterogeneous natural system, Lake Mývatn, Iceland.

Eco-evolutionary responses of natural populations to spatial environmental variation strongly depend on the relative strength of environmental differences/natural selection and dispersal/gene flow. In absence of geographic barriers, as often is the case in lake ecosystems, gene flow is expected to constrain adaptive divergence between environments - favoring phenotypic plasticity or high trait variability. However, if divergent natural selection is sufficiently strong, adaptive divergence can occur in face of gene flow. The extent of divergence is most often studied between two contrasting environments, whereas potential for multimodal divergence is little explored. We investigated phenotypic (body size, defensive structures, and feeding morphology) and genetic (microsatellites) structure in threespine stickleback (Gasterosteus aculeatus) across five habitat types and two basins (North and South) within the geologically young and highly heterogeneous Lake Mývatn, North East Iceland. We found that (1) North basin stickleback were, on average, larger and had relatively longer spines than South basin stickleback, whereas (2) feeding morphology (gill raker number and gill raker gap width) differed among three of five habitat types, and (3) there was only subtle genetic differentiation across the lake. Overall, our results indicate predator and prey mediated phenotypic divergence across multiple habitats in the lake, in face of gene flow.