The sphingosine 1-phosphate receptor S1P2 maintains the homeostasis of germinal center B cells and promotes niche confinement.

Mice deficient in sphingosine 1-phosphate receptor type 2 (S1P(2)) develop diffuse large B cell lymphoma. However, the role of S1P(2) in normal germinal center (GC) physiology is unknown. Here we show that S1P(2)-deficient GC B cells outgrew their wild-type counterparts in chronically established GCs. We found that antagonism of the kinase Akt mediated by S1P(2) and its downstream mediators Gα(12), Gα(13) and p115RhoGEF regulated cell viability and was required for growth control in chronically proliferating GCs. Moreover, S1P(2) inhibited GC B cell responses to follicular chemoattractants and helped confine cells to the GC. In addition, S1P(2) overexpression promoted the centering of activated B cells in the follicle. We suggest that by inhibiting Akt activation and migration, S1P(2) helps restrict GC B cell survival and localization to an S1P-low niche at the follicle center.

Evidence-based approach to cutaneous hyperandrogenism in women.

Hirsutism, acne, and androgenetic alopecia are classically considered signs of cutaneous hyperandrogenism (CHA). These common skin findings have significant impacts on the quality of patients' lives and pose the diagnostic challenge of excluding underlying disorders. Many with CHA have normal serum androgen levels. Hirsutism is more strongly associated with hyperandrogenism than are acne or androgenetic alopecia. Variable association of CHA with hyperandrogenemia results from the complexity of the underlying pathophysiology, including factors local to the pilosebaceous unit. CHA often occurs in the setting of polycystic ovary syndrome, the most common disorder of hyperandrogenism, but can also present in uncommon conditions, including nonclassic adrenal hyperplasia and androgen-producing tumors. A thorough history and full skin examination are important to guide appropriate diagnostic evaluation. Oral contraceptive pills with or without antiandrogens can provide therapeutic benefit for hirsutism and acne. Medical options for androgenetic alopecia remain limited. Multidisciplinary approaches may be needed given endocrine, metabolic, reproductive, and psychiatric disorders associated with CHA. More high-quality studies into the mechanisms of CHA and the benefits of antiandrogenic therapies are needed. We provide an evidence-based review of key diagnostic and therapeutic considerations in the treatment of women with CHA.

Transcriptomic Profiling of Plaque Psoriasis and Cutaneous T-Cell Subsets during Treatment with Secukinumab.

The IL-17A inhibitor secukinumab is efficacious for the treatment of psoriasis. To better understand its mechanism of action, we investigated its impact on psoriatic lesions from 15 patients with moderate-to-severe plaque psoriasis undergoing secukinumab treatment. We characterized the longitudinal transcriptomic changes of whole lesional skin tissue as well as cutaneous CD4+ and CD8+ T effector cells and CD4+ T regulatory cells across 12 weeks of treatment. Secukinumab was clinically effective and reduced disease-associated overexpression of IL17A , IL17F, IL23A, IL23R, and IFNG in whole tissue as soon as 2 weeks after initiation of treatment. IL17A overexpression in T-cell subsets, primarily CD8+ T cells, was also reduced. Although secukinumab treatment resolved 89‒97% of psoriasis-associated expression differences in bulk tissue and T-cell subsets by week 12 of treatment, we observed expression differences involved in IFN signaling and metallothionein synthesis that remained unresolved at this time point as well as potential treatment-associated expression differences involved in IL-15 signaling. These changes were accompanied by shifts in broader immune cell composition on the basis of deconvolution of RNA-sequencing data. In conclusion, our study reveals several phenotypic and cellular changes within the lesion that underlie clinical improvement from secukinumab.

The Eph-related tyrosine kinase ligand Ephrin-B1 marks germinal center and memory precursor B cells.

Identification of germinal center (GC) B cells is typically reliant on the use of surface activation markers that exhibit a wide range of expression. Here, we identify Ephrin-B1, a ligand for Eph-related receptor tyrosine kinases, as a specific marker of mature GC B cells. The number of Ephrin-B1+ GC B cells increases during the course of an immune response with Ephrin-B1+ GC B cells displaying elevated levels of Bcl6, S1pr2, and Aicda relative to their Ephrin-B1- counterparts. We further identified a small proportion of recently dividing, somatically mutated Ephrin-B1+ GC B cells that have begun to down-regulate Bcl6 and S1pr2 and express markers associated with memory B cells, such as CD38 and EBI2. Transcriptional analysis indicates that these cells are developmentally related to memory B cells, and likely represent a population of GC memory precursor (PreMem) B cells. GC PreMem cells display enhanced survival relative to bulk GC B cells, localize near the edge of the GC, and are predominantly found within the light zone. These findings offer insight into the significant heterogeneity that exists within the GC B cell population and provide tools to further dissect signals regulating the differentiation of GC B cells.

Cutaneous Findings and Systemic Associations in Women With Polycystic Ovary Syndrome.

IMPORTANCE: Understanding of the associations among cutaneous findings, systemic abnormalities, and fulfillment of the diagnostic criteria in women suspected of having polycystic ovary syndrome (PCOS) is incomplete. OBJECTIVE: To identify cutaneous and systemic features of PCOS that help distinguish women who do and do not meet the diagnostic criteria. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cross-sectional study of a racially diverse referred sample of women seen at the University of California, San Francisco, Polycystic Ovary Syndrome Multidisciplinary Clinic over a 6-year period between May 18, 2006, and October 25, 2012. Participants were 401 women referred for suspected PCOS. In total, 68.8% (276 of 401) met the Rotterdam PCOS diagnostic criteria, while 12.0% (48 of 401) did not. Overall, 11.5% (46 of 401) had insufficient data to render a diagnosis, 1.7% (7 of 401) were excluded from the study, and 6.0% (24 of 401) refused to participate in the study. EXPOSURE: Comprehensive skin examination and transvaginal ultrasonography. All patients were tested for levels of total testosterone, free testosterone, dehydroepiandrosterone (DHEAS), androstenedione, luteinizing hormone, and follicle-stimulating hormone. Levels of serum cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were obtained, in addition to 0-hour and 2-hour oral glucose tolerance test (OGTT) results, with measurement of glucose and insulin levels. MAIN OUTCOMES AND MEASURES: Findings from comprehensive skin examination, laboratory testing, and transvaginal ultrasonography. RESULTS: In total, 401 women with suspected PCOS were included in the study. The median patient age was 28 years. Compared with women who did not meet the diagnostic criteria for PCOS, women who met the criteria had higher rates of hirsutism (53.3% [144 of 270] vs 31.2% [15 of 48], P = .005) (with higher mean modified Ferriman-Gallwey scores of 8.6 vs 5.6, P = .001), acne (61.2% [164 of 268] vs 40.4% [19 of 47], P = .004), and acanthosis nigricans (AN) (36.9% [89 of 241] vs 20.0% [9 of 45], P = .03). Cutaneous distributions also varied. Women who met the PCOS criteria demonstrated more severe truncal hirsutism and higher rates of axillary AN. Women who met the PCOS criteria had elevated total testosterone levels (40.7% [105 of 258] vs 4.3% [2 of 47], P < .001). Among women with PCOS, the presence of hirsutism (43.9% [54 of 123] vs 30.9% [34 of 110], P = .04) or AN (53.3% [40 of 75] vs 27.0% [40 of 148], P < .001) was associated with higher rates of elevated free testosterone levels as well as several metabolic abnormalities, including insulin resistance, dyslipidemia, and increased body mass index. Although the prevalence of acne was increased among women with PCOS, there were minimal differences in acne types and distribution between the women meeting vs not meeting the PCOS criteria. CONCLUSIONS AND RELEVANCE: Hirsutism and AN are the most reliable cutaneous markers of PCOS and require a comprehensive skin examination to diagnose. When present, hirsutism and AN should raise clinical concern that warrants further diagnostic evaluation for metabolic comorbidities that may lead to long-term complications. Acne and androgenic alopecia are prevalent but unreliable markers of biochemical hyperandrogenism among this population.

Attitudes toward Human Papilloma Virus Vaccination and Head and Neck Cancer Prevention in a Diverse, Urban Population.

OBJECTIVE: (1) To understand if awareness of the human papilloma virus (HPV) vaccination's potential to prevent head and neck cancer improves acceptability of the vaccine in a large urban population and (2) to identify characteristics of those in whom such discussions would have the greatest impact. STUDY DESIGN: In-person, anonymous survey. SETTING: Academic public hospital between March 2014 and June 2014. SUBJECTS: Patients aged 12 to 24 years and their parents or guardians awaiting scheduled outpatient pediatric appointments. METHODS: Demographics and modified Carolina HPV Immunization Attitudes and Beliefs Scales data were cross-analyzed, followed by univariate binomial logistic regression to identify predictors for major outcomes of interest. RESULTS: More than 78% of those surveyed indicated they would be more receptive to the HPV vaccine if given strong evidence that it prevented head and neck cancer. Respondents were more likely to increase receptivity to HPV vaccination if they held the belief that they did not have enough information about the vaccine or indicated they preferred to wait because the vaccine was too new. CONCLUSION: Increasing public awareness of head and neck cancer prevention with HPV vaccination could increase HPV vaccination acceptance.

CXCR4 promotes B cell egress from Peyer's patches.

Peyer's patches (PPs) play a central role in supporting B cell responses against intestinal antigens, yet the factors controlling B cell passage through these mucosal lymphoid tissues are incompletely understood. We report that, in mixed chimeras, CXCR4-deficient B cells accumulate in PPs compared with their representation in other lymphoid tissues. CXCR4-deficient B cells egress from PPs more slowly than wild-type cells, whereas CXCR5-deficient cells egress more rapidly. The CXCR4 ligand, CXCL12, is expressed by cells adjacent to lymphatic endothelial cells in a zone that abuts but minimally overlaps with the CXCL13(+) follicle. CXCR4-deficient B cells show reduced localization to these CXCL12(+) perilymphatic zones, whereas CXCR5-deficient B cells preferentially localize in these regions. By photoconverting KikGR-expressing cells within surgically exposed PPs, we provide evidence that naive B cells transit PPs with an approximate residency half-life of 10 h. When CXCR4 is lacking, KikGR(+) B cells show a delay in PP egress. In summary, we identify a CXCL12(hi) perilymphatic zone in PPs that plays a role in overcoming CXCL13-mediated retention to promote B cell egress from these gut-associated lymphoid tissues.