Further pharmacological and genetic evidence for the efficacy of PlGF inhibition in cancer and eye disease.

Our findings that PlGF is a cancer target and anti-PlGF is useful for anticancer treatment have been challenged by Bais et al. Here we take advantage of carcinogen-induced and transgenic tumor models as well as ocular neovascularization to report further evidence in support of our original findings of PlGF as a promising target for anticancer therapies. We present evidence for the efficacy of additional anti-PlGF antibodies and their ability to phenocopy genetic deficiency or silencing of PlGF in cancer and ocular disease but also show that not all anti-PlGF antibodies are effective. We also provide additional evidence for the specificity of our anti-PlGF antibody and experiments to suggest that anti-PlGF treatment will not be effective for all tumors and why. Further, we show that PlGF blockage inhibits vessel abnormalization rather than density in certain tumors while enhancing VEGF-targeted inhibition in ocular disease. Our findings warrant further testing of anti-PlGF therapies.

Effects of E4/DRSP on self-reported physical and emotional premenstrual and menstrual symptoms: data from the phase 3 clinical trial in Europe and Russia.

PURPOSE: To describe the effects of estetrol (E4) 15 mg/drospirenone (DRSP) 3 mg on physical and emotional premenstrual and menstrual symptoms. MATERIALS AND METHODS: We used Menstrual Distress Questionnaire (MDQ) data from a phase-3 trial (NCT02817828) in Europe and Russia with participants (18 - 50 years) using E4/DRSP for up to 13 cycles. We assessed mean changes in MDQ-t-scores from baseline to end of treatment in premenstrual (4 days before most recent flow) and menstrual (most recent flow) scores for 4 MDQ domains in starters and switchers (use of hormonal contraception in prior 3 months) and performed a shift analysis on individual symptoms within each domain. RESULTS: Of 1,553 treated participants, 1,398(90.0%), including 531(38%) starters, completed both MDQs. Starters reported improvements for premenstrual Pain (-1.4), Water Retention (-3.3) and Negative Affect (-2.5); and for menstrual Pain (-3.5), Water Retention (-3.4), and Negative Affect (-2.7) (all p < 0.01). For switchers, no changes were significant except an increase in premenstrual (+1.0, p = 0.02) and menstrual (+1.5, p = 0.003) Water Retention. We observed a change in symptom intensity in >40% of participants for Cramps, Backache and Fatigue (domain Pain), Painful or Tender Breast and Swelling (domain Water Retention) and Mood Swings and Irritability (domain Negative Affect). CONCLUSION: E4/DRSP starters experienced significant improvements in the domains Pain, Water Retention and Negative Affect particularly benefiting those with more severe baseline symptoms. Switchers showed minimal changes.

A phase 3 study in Europe and Russia showed that Estetrol/Drospirenone, a new combined oral contraceptive, significantly improved the MDQ scores for domains Pain, Water Retention and Negative Affect in women starting COC use, while switchers showed minimal changes.

Comparison of Estetrol Exposure between Women and Mice to Model Preclinical Experiments and Anticipate Human Treatment.

Estetrol (E4) is a natural estrogen with promising therapeutic applications in humans. The European Medicines Agency and the Food and Drug Administration have approved the use of 15 mg E4/3 mg drospirenone for contraceptive indication. Phase III clinical trials with 15-20 mg E4 for the relief of climacteric complaints are currently running. Relevant data from preclinical animal models are needed to characterize the molecular mechanisms and the pharmacological effects of E4 and possibly to reveal new therapeutic applications and to anticipate potential adverse effects. Therefore, it is important to design experimental procedures in rodents that closely mimic or anticipate human E4 exposure. In this study, we compared the effects of E4 exposure after acute or chronic administration in women and mice. Women who received chronic E4 treatment per os at a dose of 15 mg once daily reached a steady state within 6 to 8 days, with a mean plasma concentration of 3.20 ng/mL. Importantly, with subcutaneous, intraperitoneal or oral administration of E4 in mice, a stable concentration over time that would mimic human pharmacokinetics could not be achieved. The use of osmotic minipumps continuously releasing E4 for several weeks provided an exposure profile mimicking chronic oral administration in women. Measurements of the circulating concentration of E4 in mice revealed that the mouse equivalent dose necessary to mimic human treatment does not fit with the allometric prediction. In conclusion, this study highlights the importance of precise definition of the most appropriate dose and route of administration to utilize when developing predictive preclinical animal models to mimic or anticipate specific human treatment.

A novel estetrol-containing combined oral contraceptive: European expert panel review.

PURPOSE: Despite considerable advances in recently developed combined oral contraceptives (COCs), resulting in lower rates of adverse events while maintaining contraceptive efficacy, there is interest in further innovation. MATERIALS AND METHODS: Estetrol (E4), a native oestrogen, and progestin drospirenone (DRSP) were combined in a new COC. A European expert panel reviewed the pharmacology, efficacy, and safety and tolerability of this combination. Their findings are presented as a narrative review. RESULTS: E4 15 mg/DRSP 3 mg in a 24/4 regimen provided effective contraception with good cycle control, characterised by a predictable regular bleeding pattern and minimal unscheduled bleeding, together with a good safety profile. The combination was associated with high user satisfaction, well-being, and minimal changes in body weight. The effects on endocrine and metabolic parameters were limited, and the combination was found to have a limited impact on liver function and lipid and carbohydrate metabolism. Moreover, its effect on several haemostatic parameters was lower than that of comparators containing ethinyl oestradiol (EE) 20 µg/DRSP 3 mg and EE 30 µg/levonorgestrel 150 µg. CONCLUSION: E4 15 mg/DRSP 3 mg provides safe and effective contraception, with high user satisfaction and predictable bleeding. Further research will evaluate the long-term safety of the COC.

A novel estetrol-containing combined oral contraceptive: European expert panel review.

PURPOSE: Despite considerable advances in recently developed combined oral contraceptives (COCs), resulting in lower rates of adverse events while maintaining contraceptive efficacy, there is interest in further innovation. MATERIALS AND METHODS: Estetrol (E4), a native oestrogen, and progestin drospirenone (DRSP) were combined in a new COC. A European expert panel reviewed the pharmacology, efficacy, and safety and tolerability of this combination. Their findings are presented as a narrative review. RESULTS: E4 15mg/DRSP 3 mg in a 24/4 regimen provided effective contraception with good cycle control, characterised by a predictable regular bleeding pattern and minimal unscheduled bleeding, together with a good safety profile. The combination was associated with high user satisfaction, wellbeing, and minimal changes in body weight. The effects on endocrine and metabolic parameters were limited, and the combination was found to have a limited impact on liver function and lipid and carbohydrate metabolism. Moreover, its effect on several haemostatic parameters was lower than that of comparators containing ethinyl oestradiol (EE) 20mg/DRSP 3 mg and EE 30mg/levonorgestrel 150mg. CONCLUSION: E4 15 mg/DRSP 3 mg provides safe and effective contraception, with high user satisfaction and predictable bleeding. Further research will evaluate the long-term safety of the COC.

Estetrol and Mammary Gland: Friends or Foes?

Estrogens have pleiotropic effects on many reproductive and non-reproductive tissues and organs including the mammary gland, uterus, ovaries, vagina, and endothelium. Estrogen receptor α functions as the principal mediator of estrogenic action in most of these tissues. Estetrol (E4) is a native fetal estrogen with selective tissue actions that is currently approved for use as the estrogen component in a combined oral contraceptive and is being developed as a menopause hormone therapy (MHT, also known as hormone replacement therapy). However, exogenous hormonal treatments, in particular MHTs, have been shown to promote the growth of preexisting breast cancers and are associated with a variable risk of breast cancer depending on the treatment modality. Therefore, evaluating the safety of E4-based formulations on the breast forms a crucial part of the clinical development process. This review highlights preclinical and clinical studies that have assessed the effects of E4 and E4-progestogen combinations on the mammary gland and breast cancer, focusing in particular on the estrogenic and anti-estrogenic properties of E4. We discuss the potential advantages of E4 over current available estrogen-formulations as a contraceptive and for the treatment of symptoms due to menopause. We also consider the potential of E4 for the treatment of endocrine-resistant breast cancer.

Estetrol prevents Western diet-induced obesity and atheroma independently of hepatic estrogen receptor α.

Estetrol (E4), a natural estrogen synthesized by the human fetal liver, is currently evaluated in phase III clinical studies as a new menopause hormone therapy. Indeed, E4 significantly improves vasomotor and genito-urinary menopausal symptoms and prevents bone demineralization. Compared with other estrogens, E4 was found to have limited effects on coagulation factors in the liver of women allowing to expect less thrombotic events. To fully delineate its clinical potential, the aim of this study was to assess the effect of E4 on metabolic disorders. Here, we studied the pathophysiological consequences of a Western diet (42% kcal fat, 0.2% cholesterol) in ovariectomized female mice under chronic E4 treatment. We showed that E4 reduces body weight gain and improves glucose tolerance in both C57Bl/6 and LDLR-/- mice. To evaluate the role of hepatic estrogen receptor (ER) α in the preventive effect of E4 against obesity and associated disorders such as atherosclerosis and steatosis, mice harboring a hepatocyte-specific ERα deletion (LERKO) were crossed with LDLR-/- mice. Our results demonstrated that, whereas liver ERα is dispensable for the E4 beneficial actions on obesity and atheroma, it is necessary to prevent steatosis in mice. Overall, these findings suggest that E4 could prevent metabolic, hepatic, and vascular disorders occurring at menopause, extending the potential medical interest of this natural estrogen as a new hormonal treatment.NEW & NOTEWORTHY Estetrol prevents obesity, steatosis, and atherosclerosis in mice fed a Western diet. Hepatic ERα is necessary for the prevention of steatosis, but not of obesity and atherosclerosis.

Comparison of two levonorgestrel-releasing intrauterine systems for the treatment of heavy menstrual bleeding: a randomised, controlled, phase 3 trial.

PURPOSE: To evaluate the levonorgestrel-releasing intrauterine system Donasert® (also known as Levosert®) compared with the reference product Mirena® for the alleviation of heavy menstrual bleeding (HMB). MATERIALS AND METHODS: A phase 3 multicentre, non-inferiority, active-controlled study in non-menopausal women with HMB (menstrual blood loss [MBL] ≥ 80 mL) as the primary symptom randomised to either Donasert® or Mirena® and followed for 6 months. MBL was evaluated using a validated, modified version of the Wyatt pictogram. RESULTS: Overall, 312 were randomised (158 to Donasert® and 154 to Mirena®). The mean (standard deviation) absolute change in MBL from baseline to 6 months in the per-protocol population (N = 300) was -130 (71.8) mL and -127 (67.3) mL in the Donasert® and Mirena® groups, respectively; non-inferiority of Donasert® was confirmed (p-value <0.0001). Successful treatment of HMB (MBL <80 mL) and a decrease to ≤50% of baseline MBL was achieved in 139/154 (90.3%) and 126/146 (86.3%) participants in the Donasert® and Mirena® groups, respectively and the between-treatment difference was non-significant. Most adverse events were mild in severity. Only two device expulsions occurred in the study and there were no uterine perforations. CONCLUSIONS: Donasert® has equivalent efficacy and safety during the first 6 months foralleviation of HMB compared to the reference device, Mirena®. TRIAL REGISTRATION NUMBER: 348 (Clinical Trials Registry of the Ministry of Health of the Russian Federation, http://grls.rosminzdrav.ru/default.aspx).

Absence of correlation between follicular fluid volume and follicular granulocyte colony-stimulating factor, a predictor of embryo implantation and successful delivery.

Follicular granulocyte colony-stimulating factor (G-CSF) is a documented marker of embryo implantation potential. The primary objective was to determine whether follicular G-CSF levels correlate with follicular fluid volume. The secondary objectives were to assess whether follicular G-CSF is associated with oocyte maturity at the time of harvest and with delivery rate after fresh or frozen embryo transfer. Thirty-two patients undergoing intracytoplasmic sperm injection (ICSI) cycles were recruited (Centre de Procréation Médicalement Assistée (CPMA), University of Liège, Belgium). A total of 211 follicular fluid (FF) samples were individually collected at the time of oocyte harvest. FF volume was recorded, and G-CSF concentration was assessed by ELISA. The embryos were individually cultured in vitro. Their implantation and live birth rates were recorded after fresh and frozen embryo transfers. The follicular fluid volume did not correlate with the follicular G-CSF concentration. There were no differences in follicular G-CSF levels between mature and immature oocytes. The probability of successful implantation and delivery was increased for embryos with FF containing a high G-CSF concentration. There was a trend toward lower follicular G-CSF levels in cases of miscarriage. Therefore, follicular fluid volume cannot be a substitute for follicular G-CSF as a marker of embryo implantation ability.

A paracrine interaction between granulosa cells and leukocytes in the preovulatory follicle causes the increase in follicular G-CSF levels.

OBJECTIVE: Follicular granulocyte colony-stimulating factor (G-CSF) is a new biomarker of oocyte quality and embryo implantation in in vitro fertilization (IVF) cycles. Its role in reproduction is poorly understood. Our study aimed to investigate the mechanisms and cells responsible for G-CSF production in the preovulatory follicle. DESIGN: Laboratory research study. SETTING: Single-center study. INTERVENTIONS: Granulosa cells and leukocytes were isolated from the follicular fluids (FF) or the blood of women undergoing IVF and from the blood of a control group of women with spontaneous ovulatory cycles to perform cocultures. MAIN OUTCOME MEASURE: G-CSF-secreted protein was quantified in the conditioned media of cocultures. RESULTS: G-CSF secretion was considerably increased in cocultures of granulosa cells and leukocytes. This effect was maximal when leukocytes were isolated from the blood of women in the late follicular phase of the menstrual cycle or from the FF of women undergoing IVF. The leukocyte population isolated from the FF samples of women undergoing IVF had a higher proportion of granulocytes than that isolated from the corresponding blood samples. Leukocytes induced the synthesis and secretion of G-CSF by granulosa cells. Among a range of other FF cytokines/chemokines, only growth-regulated oncogene alpha (GROα) was also increased. CONCLUSION: The notable rise in G-CSF at the time of ovulation coincides with the accumulation of follicular granulocytes, which stimulate G-CSF production by granulosa cells via paracrine interactions. High follicular G-CSF concentrations may occur in follicles with optimal granulosa-leukocyte interactions, which could explain the increased implantation rate of embryos arising from these follicles.

Estetrol, a Fetal Selective Estrogen Receptor Modulator, Acts on the Vagina of Mice through Nuclear Estrogen Receptor α Activation.

The genitourinary syndrome of menopause has a negative impact on quality of life of postmenopausal women. The treatment of vulvovaginal atrophy includes administration of estrogens. However, oral estrogen treatment is controversial because of its potential risks on venous thrombosis and breast cancer. Estetrol (E4) is a natural estrogen synthesized exclusively during pregnancy by the human fetal liver and initially considered as a weak estrogen. However, E4 was recently evaluated in phase 1 to 2 clinical studies and found to act as an oral contraceptive in combination with a progestin, without increasing the level of coagulation factors. We recently showed that E4 stimulates uterine epithelial proliferation through nuclear estrogen receptor (ER) α, but failed to elicit endothelial responses. Herein, we first evaluated the morphological and functional impacts of E4 on the vagina of ovariectomized mice, and we determined the molecular mechanism mediating these effects. Vaginal epithelial proliferation and lubrication after stimulation were found to increase after E4 chronic treatment. Using a combination of pharmacological and genetic approaches, we demonstrated that these E4 effects on the vagina are mediated by nuclear ERα activation. Altogether, we demonstrate that the selective activation of nuclear ERα is both necessary and sufficient to elicit functional and structural effects on the vagina, and therefore E4 appears promising as a therapeutic option to improve vulvovaginal atrophy.

Heterogeneity of estrogen receptor α and progesterone receptor distribution in lesions of deep infiltrating endometriosis of untreated women or during exposure to various hormonal treatments.

Deep infiltrating endometriosis (DIE) responds variably to hormonal therapy. Mutations in cancer driver genes have been identified in a fraction of the ectopic endometrial epithelial cells, suggesting a functional heterogeneity of these lesions. To evaluate the phenotype heterogeneity of cells in DIE, we measured the expression of estrogen receptor α (ERα) and of progesterone receptor (PR) in DIE of untreated women or under various treatments. We analyzed the luminal epithelial height (LEH), immunoreactive epithelial staining (IRS) and stromal staining intensity (SSI) of ERα and PR. We observed a high variability in the same gland, among distinct glands in the same sample and among distinct patients receiving the same treatment. LEH variability was primarily due to epithelial cells heterogeneity in a gland, secondarily to the glands randomly evaluated on the same section, and tertiary to the patient category. Variability in IRS and SSI scores was primarily the consequence of their heterogeneity in the same woman and to a lesser extent to variability among patients. LEH and SSI were not modified according to treatment. IRS for PR was lower in treated patients. This heterogeneity of ERα and PR distribution could explain why endocrine treatments are unable to cure this condition.

The Activation Function-1 of Estrogen Receptor Alpha Prevents Arterial Neointima Development Through a Direct Effect on Smooth Muscle Cells.

RATIONALE: 17ß-Estradiol (E2) exerts numerous beneficial effects in vascular disease. It regulates gene transcription through nuclear estrogen receptor α (ERα) via 2 activation functions, AF1 and AF2, and can also activate membrane ERα. The role of E2 on the endothelium relies on membrane ERα activation, but the molecular mechanisms of its action on vascular smooth muscle cells (VSMCs) are not fully understood. OBJECTIVE: The aim of this study was to determine which cellular target and which ERα subfunction are involved in the preventive action of E2 on neointimal hyperplasia. METHODS AND RESULTS: To trigger neointimal hyperplasia of VSMC, we used a mouse model of femoral arterial injury. Cre-Lox models were used to distinguish between the endothelial- and the VSMC-specific actions of E2. The molecular mechanisms underlying the role of E2 were further characterized using both selective ERα agonists and transgenic mice in which the ERαAF1 function had been specifically invalidated. We found that (1) the selective inactivation of ERα in VSMC abrogates the neointimal hyperplasia protection induced by E2, whereas inactivation of endothelial and hematopoietic ERα has no effect; (2) the selective activation of membrane ERα does not prevent neointimal hyperplasia; and (3) ERαAF1 is necessary and sufficient to inhibit postinjury VSMC proliferation. CONCLUSIONS: Altogether, ERαAF1-mediated nuclear action is both necessary and sufficient to inhibit postinjury arterial VSMC proliferation, whereas membrane ERα largely regulates the endothelial functions of E2. This highlights the exquisite cell/tissue-specific actions of the ERα subfunctions and helps to delineate the spectrum of action of selective ER modulators.

Estetrol combined with drospirenone: an oral contraceptive with high acceptability, user satisfaction, well-being and favourable body weight control.

OBJECTIVES: This study evaluated acceptability, user satisfaction, body weight control and general well-being of estetrol (E4) combined with either drospirenone (DRSP) or levonorgestrel (LNG). METHODS: In this open-label, multi-centre, dose-finding, 6-cycle study, 396 healthy women of reproductive age were randomised into five treatment groups in a 24/4-day regimen: 15 mg or 20 mg E4 combined with either 3 mg DRSP or 150 µg LNG, and as reference estradiol valerate (E2V) combined with dienogest (DNG). Data on acceptability, user well-being, satisfaction and body weight were collected. RESULTS: The number of completers was the highest in the 15 mg E4/DRSP group (91.1%), and the lowest for 20 mg E4/LNG (70.1%). The largest proportion of treatment satisfaction was reported for 15 mg E4/DRSP (73.1%), and the lowest for 15 mg E4/LNG (50.6%). The number of women willing to continue with the assigned study treatment was the highest in the 15 mg E4/DRSP group (82.1%) and the lowest for 20 mg E4/LNG (58.3%). Well-being with E4/DRSP combinations was statistically significantly better than with E4/LNG combinations: OR (95% CI) 2.00 (1.13; 3.53) and 1.93 (1.06; 3.56) for 15 and 20 mg E4, respectively, and comparable to E2V/DNG. Proportion of women with a 2 kg or more weight loss after 3 and 6 cycles was the highest in the 15 mg E4/DRSP group (30.7 and 36.7%, respectively). CONCLUSIONS: The present study shows that 15 mg estetrol combined with 3 mg DRSP is associated with a high-user acceptability and satisfaction, and with a favourable body weight control.

Soluble factors regulated by epithelial-mesenchymal transition mediate tumour angiogenesis and myeloid cell recruitment.

Epithelial-mesenchymal transition (EMT) programmes provide cancer cells with invasive and survival capacities that might favour metastatic dissemination. Whilst signalling cascades triggering EMT have been extensively studied, the impact of EMT on the crosstalk between tumour cells and the tumour microenvironment remains elusive. We aimed to identify EMT-regulated soluble factors that facilitate the recruitment of host cells in the tumour. Our findings indicate that EMT phenotypes relate to the induction of a panel of secreted mediators, namely IL-8, IL-6, sICAM-1, PAI-1 and GM-CSF, and implicate the EMT-transcription factor Snail as a regulator of this process. We further show that EMT-derived soluble factors are pro-angiogenic in vivo (in the mouse ear sponge assay), ex vivo (in the rat aortic ring assay) and in vitro (in a chemotaxis assay). Additionally, conditioned medium from EMT-positive cells stimulates the recruitment of myeloid cells. In a bank of 40 triple-negative breast cancers, tumours presenting features of EMT were significantly more angiogenic and infiltrated by a higher quantity of myeloid cells compared to tumours with little or no EMT. Taken together, our results show that EMT programmes trigger the expression of soluble mediators in cancer cells that stimulate angiogenesis and recruit myeloid cells in vivo, which might in turn favour cancer spread.

Elastin density: Link between histological and biomechanical properties of vaginal tissue in women with pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS: The aim of the study was to correlate histological and biomechanical characteristics of the vaginal wall in women with pelvic organ prolapse (POP). METHODS: Tissue samples were collected from the anterior [point Ba; POP Questionnaire (POP-Q)] and/or posterior (point Bp; POP-Q) vaginal wall of 15 women who underwent vaginal surgery for POP. Both histological and biomechanical assessments were performed from the same tissue samples in 14 of 15 patients. For histological assessment, the density of collagen and elastin fibers was determined by combining high-resolution virtual imaging and computer-assisted digital image analysis. For biomechanical testing, uniaxial tension tests were performed to evaluate vaginal tissue stiffness at low (C0) and high (C1) deformation rates. RESULTS: Biomechanical testing highlights the hyperelastic behavior of the vaginal wall. At low strains (C0), vaginal tissue appeared stiffer when elastin density was low. We found a statistically significant inverse relationship between C0 and the elastin/collagen ratio (p = 0.048) in the lamina propria. However, at large strain levels (C1), no clear relationship was observed between elastin density or elastin/collagen ratio and stiffness, likely reflecting the large dispersion of the mechanical behavior of the tissue samples. CONCLUSION: Histological and biomechanical properties of the vaginal wall vary from patient to patient. This study suggests that elastin density deserves consideration as a relevant factor of vaginal stiffness in women with POP.

Isoform 165 of vascular endothelial growth factor in collagen matrix improves ovine cryopreserved ovarian tissue revascularisation after xenotransplantation in mice.

BACKGROUND: Aggressive anti-cancer treatments can result in ovarian failure. Ovarian cryopreservation has been developed to preserve the fertility of young women, but early graft revascularisation still requires improvement. METHODS: Frozen/thawed sheep ovarian cortical biopsies were embedded in collagen matrix with or without isoform 165 of vascular endothelial growth factor (VEGF165) and transplanted into ovaries of immunodeficient mice. Ovaries were chosen as transplantation sites to more closely resemble clinical conditions in which orthotopic transplantation has previously allowed several spontaneous pregnancies. RESULTS: We found that VEGF165 significantly increased the number of Dextran-FITC positive functional vessels 3 days after grafting. Dextran- fluorescein isothiocyanate (FITC) positive vessels were detectable in 53% and 29% of the mice in the VEGF-treated and control groups, respectively. Among these positive fragments, 50% in the treated group displayed mature smooth-muscle-actin-alpha (alpha-SMA) positive functional vessels compared with 0% in the control group. CD31 positive murine blood vessels were observed in 40% of the VEGF165 transplants compared with 21% of the controls. After 3 weeks, the density of murine vessels was significantly higher in the VEGF165 group. CONCLUSION: The encapsulation of ovarian tissue in collagen matrix in the presence of VEGF165 before grafting has a positive effect on functional blood vessel recruitment. It can be considered as a useful technique to be improved and further developed before human clinical applications in female cancer patients in the context of fertility preservation.

Altered α-defensin 5 expression in cervical squamocolumnar junction: implication in the formation of a viral/tumour-permissive microenvironment.

Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix, which mainly develops at the squamocolumnar (SC) junction. The progression of cervical HPV infections into (pre)neoplastic lesions suggests that viral antigens are not adequately recognized by innate immunity or presented to the adaptive immune system. Members of the defensin family have recently been found to inhibit viral and bacterial pathogens, to stimulate the migration of immune cells and to play a role in anticancer responses. In the present study, we focused on the poorly characterized human α-defensin 5 (HD-5) and its possible role in these processes. We showed that HD-5 was able to prevent HPV virion entry into cervical keratinocytes and to influence adaptive immunity. Indeed, this peptide specifically induced the chemoattraction and proliferation of both activated T lymphocytes and immature dendritic cells in a CCR2/CCR6-dependent manner and stimulated the infiltration of these professional antigen-presenting cells in a (pre)neoplastic epithelium transplanted in vivo in immunodeficient mice. No chemotactic effect was observed with plasmacytoid dendritic cells, macrophages or natural killer cells. Proliferative and angiogenic effects of HD-5 were also assessed in vitro and in vivo. However there was a striking regional disparity in expression of HD-5, being prominent in ectocervical, vaginal and vulvar neoplasia, while absent, or nearly so, in the cervical SC junction. Taken together, these results suggest one possible explanation for why the SC junction is uniquely vulnerable to both high-risk HPV infection (via reduced HD-5 expression and viral entry) and progression of neoplasia (via altered cell-mediated immune responses and altered microenvironment).