Crosslinking of Ly6a metabolically reprograms CD8 T cells for cancer immunotherapy.

T cell inhibitory mechanisms prevent autoimmune reactions, while cancer immunotherapy aims to remove these inhibitory signals. Chronic ultraviolet (UV) exposure attenuates autoimmunity through promotion of poorly understood immune-suppressive mechanisms. Here we show that mice with subcutaneous melanoma are not responsive to anti-PD1 immunotherapy following chronic UV irradiation, given prior to tumor injection, due to the suppression of T cell killing ability in skin-draining lymph nodes.

Affinity gaps among B cells in germinal centers drive the selection of MPER precursors.

Current prophylactic human immunodeficiency virus 1 (HIV-1) vaccine research aims to elicit broadly neutralizing antibodies (bnAbs). Membrane-proximal external region (MPER)-targeting bnAbs, such as 10E8, provide exceptionally broad neutralization, but some are autoreactive. Here, we generated humanized B cell antigen receptor knock-in mouse models to test whether a series of germline-targeting immunogens could drive MPER-specific precursors toward bnAbs.

Impairing hydrolase transport machinery prevents human melanoma metastasis.

Metastases are the major cause of cancer-related death, yet, molecular weaknesses that could be exploited to prevent tumor cells spreading are poorly known. Here, we found that perturbing hydrolase transport to lysosomes by blocking either the expression of IGF2R, the main receptor responsible for their trafficking, or GNPT, a transferase involved in the addition of the specific tag recognized by IGF2R, reduces melanoma invasiveness potential. Mechanistically, we demonstrate that the perturbation of this traffic, leads to a compensatory lysosome neo-biogenesis devoided of degradative enzymes.

Recycled melanoma-secreted melanosomes regulate tumor-associated macrophage diversification.

Extracellular vesicles (EVs) are important mediators of communication between cells. Here, we reveal a new mode of intercellular communication by melanosomes, large EVs secreted by melanocytes for melanin transport. Unlike small EVs, which are disintegrated within the receiver cell, melanosomes stay intact within them, gain a unique protein signature, and can then be further transferred to another cell as "second-hand" EVs.

Seasonal AMH variability implies a positive effect of UV exposure on the deterioration of ovarian follicles.

Anti-Müllerian hormone (AMH) is produced exclusively by granulosa cells of ovarian follicles and is an indicator of ovarian reserve which declines with age. Seasonality in AMH levels have been reported to be correlated with variations in Vitamin D levels, which is dependent on sunlight exposure. However, the effects of age and its association with solar radiation intensity with respect to AMH was never studied before.

Ataxia Telangiectasia Mutated Signaling Delays Skin Pigmentation upon UV Exposure by Mediating MITF Function toward DNA Repair Mode.

Skin pigmentation is paused after sun exposure; however, the mechanism behind this pausing is unknown. In this study, we found that the UVB-induced DNA repair system, led by the ataxia telangiectasia mutated (ATM) protein kinase, represses MITF transcriptional activity of pigmentation genes while placing MITF in DNA repair mode, thus directly inhibiting pigment production. Phosphoproteomics analysis revealed ATM to be the most significantly enriched pathway among all UVB-induced DNA repair systems.

An Exercise-Induced Metabolic Shield in Distant Organs Blocks Cancer Progression and Metastatic Dissemination.

Unlabelled: Exercise prevents cancer incidence and recurrence, yet the underlying mechanism behind this relationship remains mostly unknown. Here we report that exercise induces the metabolic reprogramming of internal organs that increases nutrient demand and protects against metastatic colonization by limiting nutrient availability to the tumor, generating an exercise-induced metabolic shield. Proteomic and ex vivo metabolic capacity analyses of murine internal organs revealed that exercise induces catabolic processes, glucose uptake, mitochondrial activity, and GLUT expression.

Identification of UDP-Glucuronosyltransferase 2B15 (UGT2B15) as a Target for IGF1 and Insulin Action.

Normal growth and development in mammals are tightly controlled by numerous genetic factors and metabolic conditions. The growth hormone (GH)-insulin-like growth factor-1 (IGF1) hormonal axis is a key player in the regulation of these processes. Dysregulation of the GH-IGF1 endocrine system is linked to a number of pathologies, ranging from growth deficits to cancer.

Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior.

Ultraviolet (UV) light affects endocrinological and behavioral aspects of sexuality via an unknown mechanism. Here we discover that ultraviolet B (UVB) exposure enhances the levels of sex-steroid hormones and sexual behavior, which are mediated by the skin. In female mice, UVB exposure increases hypothalamus-pituitary-gonadal axis hormone levels, resulting in larger ovaries; extends estrus days; and increases anti-Mullerian hormone (AMH) expression.

Slow Transcription of the 99a/let-7c/125b-2 Cluster Results in Differential MiRNA Expression and Promotes Melanoma Phenotypic Plasticity.

Almost half of the human microRNAs (miRNAs) are encoded in clusters. Although transcribed as a single unit, the levels of individual mature miRNAs often differ. The mechanisms underlying differential biogenesis of clustered miRNAs and the resulting physiological implications are mostly unknown.

DNA methylation directs microRNA biogenesis in mammalian cells.

MicroRNA (miRNA) biogenesis initiates co-transcriptionally, but how the Microprocessor machinery pinpoints the locations of short precursor miRNA sequences within long flanking regions of the transcript is not known. Here we show that miRNA biogenesis depends on DNA methylation. When the regions flanking the miRNA coding sequence are highly methylated, the miRNAs are more highly expressed, have greater sequence conservation, and are more likely to drive cancer-related phenotypes than miRNAs encoded by unmethylated loci.

UV-Protection Timer Controls Linkage between Stress and Pigmentation Skin Protection Systems.

Skin sun exposure induces two protection programs: stress responses and pigmentation, the former within minutes and the latter only hours afterward. Although serving the same physiological purpose, it is not known whether and how these programs are coordinated. Here, we report that UVB exposure every other day induces significantly more skin pigmentation than the higher frequency of daily exposure, without an associated increase in stress responses.

Mutated MITF-E87R in Melanoma Enhances Tumor Progression via S100A4.

Melanoma, a melanocyte origin neoplasm, is the most lethal type of skin cancer, and incidence is increasing. Several familial and somatic mutations have been identified in the gene encoding the melanocyte lineage master regulator, MITF; however, the neoplastic mechanisms of these mutant MITF variants are mostly unknown. Here, by performing unbiased analysis of the transcriptomes in cells expressing mutant MITF, we identified calcium-binding protein S100A4 as a downstream target of MITF-E87R.

OCT4 impedes cell fate redirection by the melanocyte lineage master regulator MITF in mouse ESCs.

Ectopic expression of lineage master regulators induces transdifferentiation. Whether cell fate transitions can be induced during various developmental stages has not been systemically examined. Here we discover that amongst different developmental stages, mouse embryonic stem cells (mESCs) are resistant to cell fate conversion induced by the melanocyte lineage master regulator MITF.