Patients taking benralizumab, dupilumab, or mepolizumab have lower postvaccination SARS-CoV-2 immunity.

BACKGROUND: Biologic therapies inhibiting the IL-4 or IL-5 pathways are very effective in the treatment of asthma and other related conditions. However, the cytokines IL-4 and IL-5 also play a role in the generation of adaptive immune responses. Although these biologics do not cause overt immunosuppression, their effect in primary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization has not been studied completely. OBJECTIVE: Our aim was to evaluate the antibody and cellular immunity after SARS-CoV-2 mRNA vaccination in patients on biologics (PoBs). METHODS: Patients with severe asthma or atopic dermatitis who were taking benralizumab, dupilumab, or mepolizumab and had received the initial dose of the 2-dose adult SARS-CoV-2 mRNA vaccine were enrolled in a prospective, observational study. As our control group, we used a cohort of immunologically healthy subjects (with no significant immunosuppression) who were not taking biologics (NBs). We used a multiplexed immunoassay to measure antibody levels, neutralization assays to assess antibody function, and flow cytometry to quantitate Spike-specific lymphocytes. RESULTS: We analyzed blood from 57 patients in the PoB group and 46 control subjects from the NB group. The patients in the PoB group had lower levels of SARS-CoV-2 antibodies, pseudovirus neutralization, live virus neutralization, and frequencies of Spike-specific B and CD8 T cells at 6 months after vaccination. In subgroup analyses, patients with asthma who were taking biologics had significantly lower pseudovirus neutralization than did subjects with asthma who were not taking biologics. CONCLUSION: The patients in the PoB group had reduced SARS-CoV-2-specific antibody titers, neutralizing activity, and virus-specific B- and CD8 T-cell counts. These results have implications when considering development of a more individualized immunization strategy in patients who receive biologic medications blocking IL-4 or IL-5 pathways.

Pulmonary Function and Quality of Life in Adults with Cystic Fibrosis.

PURPOSE: People living with cystic fibrosis (CF) experience impaired quality of life, but the extent to which pulmonary function is associated with quality of life in CF remains unclear METHODS: Using baseline data from a trial of specialist palliative care in adults with CF, we examined the association between pulmonary obstruction and quality of life (measured with the Functional Assessment of Chronic Illness Therapy Total Score). RESULTS: Among 262 participants, median age was 33, and 78% were on modulator therapy. The median quality of life score was higher in those with mild obstruction (135, IQR 110-156) compared to moderate (125, IQR 109-146) and severe obstruction (120, IQR 106-136). In an unadjusted model, we observed a non-significant trend toward lower quality of life with increased obstruction-compared to participants with mild obstruction, those with moderate obstruction had quality of life score 7.46 points lower (95% CI -15.03 to 0.10) and those with severe obstruction had a score 9.98 points lower (95% CI -21.76 to 1.80). However, this association was no longer statistically significant in the adjusted model, which may reflect confounding due to sex, age, BMI, and modulator therapy. Comorbidities (depression and anxiety) and social determinants of health (financial insecurity and education) were also associated with quality of life. CONCLUSION: Advancing our understanding of patient-centered markers of quality of life, rather than focusing on pulmonary function alone, may help identify novel interventions to improve quality of life in this patient population.

A non-catalytic function of PI3Kγ drives smooth muscle cell proliferation after arterial damage.

Arterial remodeling in hypertension and intimal hyperplasia involves inflammation and disrupted flow, both of which contribute to smooth muscle cell dedifferentiation and proliferation. In this context, our previous results identified phosphoinositide 3-kinase γ (PI3Kγ) as an essential factor in inflammatory processes of the arterial wall. Here, we identify for the first time a kinase-independent role of nonhematopoietic PI3Kγ in the vascular wall during intimal hyperplasia using PI3Kγ-deleted mice and mice expressing a kinase-dead version of the enzyme. Moreover, we found that the absence of PI3Kγ in vascular smooth muscle cells (VSMCs) leads to modulation of cell proliferation, associated with an increase in intracellular cAMP levels. Real-time analysis of cAMP dynamics revealed that PI3Kγ modulates the degradation of cAMP in primary VSMCs independently of its kinase activity through regulation of the enzyme phosphodiesterase 4. Importantly, the use of an N-terminal competing peptide of PI3Kγ blocked primary VSMC proliferation. These data provide evidence for a kinase-independent role of PI3Kγ in arterial remodeling and reveal novel strategies targeting the docking function of PI3Kγ for the treatment of cardiovascular diseases.

Tamoxifen Accelerates Endothelial Healing by Targeting ERα in Smooth Muscle Cells.

RATIONALE: Tamoxifen prevents the recurrence of breast cancer and is also beneficial against bone demineralization and arterial diseases. It acts as an ER (estrogen receptor) α antagonist in ER-positive breast cancers, whereas it mimics the protective action of 17ß-estradiol in other tissues such as arteries. However, the mechanisms of these tissue-specific actions remain unclear. OBJECTIVE: Here, we tested whether tamoxifen is able to accelerate endothelial healing and analyzed the underlying mechanisms. METHODS AND RESULTS: Using 3 complementary mouse models of carotid artery injury, we demonstrated that both tamoxifen and estradiol accelerated endothelial healing, but only tamoxifen required the presence of the underlying medial smooth muscle cells. Chronic treatment with 17ß-estradiol and tamoxifen elicited differential gene expression profiles in the carotid artery. The use of transgenic mouse models targeting either whole ERα in a cell-specific manner or ERα subfunctions (membrane/extranuclear versus genomic/transcriptional) demonstrated that 17ß-estradiol-induced acceleration of endothelial healing is mediated by membrane ERα in endothelial cells, while the effect of tamoxifen is mediated by the nuclear actions of ERα in smooth muscle cells. CONCLUSIONS: Whereas tamoxifen acts as an antiestrogen and ERα antagonist in breast cancer but also on the membrane ERα of endothelial cells, it accelerates endothelial healing through activation of nuclear ERα in smooth muscle cells, inviting to revisit the mechanisms of action of selective modulation of ERα.

Thermodynamic Study of Formamidinium Lead Iodide (CH5N2PbI3) from 5 to 357 K.

In the present study, the molar heat capacity of solid formamidinium lead iodide (CH5N2PbI3) was measured over the temperature range from 5 to 357 K using a precise automated adiabatic calorimeter. In the above temperature interval, three distinct phase transitions were found in ranges from 49 to 56 K, from 110 to 178 K, and from 264 to 277 K. The standard thermodynamic functions of the studied perovskite, namely the heat capacity C°p(T), enthalpy [H0(T) - H0(0)], entropy S0(T), and [G°(T) - H°(0)]/T, were calculated for the temperature range from 0 to 345 K based on the experimental data. Herein, the results are discussed and compared with those available in the literature as measured by nonclassical methods.

Cathepsin B promotes collagen biosynthesis, which drives bronchiolitis obliterans syndrome.

Bronchiolitis obliterans syndrome (BOS) is a major complication after lung transplantation (LTx). BOS is characterised by massive peribronchial fibrosis, leading to air trapping-induced pulmonary dysfunction. Cathepsin B, a lysosomal cysteine protease, has been shown to enforce fibrotic pathways in several diseases. However, the relevance of cathepsin B in BOS progression has not yet been addressed. The aim of the study was to elucidate the function of cathepsin B in BOS pathogenesis.We determined cathepsin B levels in bronchoalveolar lavage fluid (BALF) and lung tissue from healthy donors (HD) and BOS LTx patients. Cathepsin B activity was assessed via a fluorescence resonance energy transfer-based assay and protein expression was determined using Western blotting, ELISA and immunostaining. To investigate the impact of cathepsin B in the pathophysiology of BOS, we used an in vivo orthotopic left LTx mouse model. Mechanistic studies were performed in vitro using macrophage and fibroblast cell lines.We found a significant increase of cathepsin B activity in BALF and lung tissue from BOS patients, as well as in our murine model of lymphocytic bronchiolitis. Moreover, cathepsin B activity was associated with increased biosynthesis of collagen and had a negative effect on lung function. We observed that cathepsin B was mainly expressed in macrophages that infiltrated areas characterised by a massive accumulation of collagen deposition. Mechanistically, macrophage-derived cathepsin B contributed to transforming growth factor-ß1-dependent activation of fibroblasts, and its inhibition reversed the phenotype.Infiltrating macrophages release active cathepsin B, thereby promoting fibroblast activation and subsequent collagen deposition, which drive BOS. Cathepsin B represents a promising therapeutic target to prevent the progression of BOS.

Thermodynamic Properties of the First-Generation Hybrid Dendrimer with "Carbosilane Core/Phenylene Shell" Structure.

The molar heat capacity of the first-generation hybrid dendrimer with a "carbosilane core/phenylene shell" structure was measured for the first time in the temperature range T = 6-600 K using a precise adiabatic vacuum calorimeter and DSC. In the above temperature interval, the glass transition of the studied compound was observed, and its thermodynamic characteristics were determined. The standard thermodynamic functions (the enthalpy, the entropy, and the Gibbs energy) of the hybrid dendrimer were calculated over the range from T = 0 to 600 K using the experimentally determined heat capacity. The standard entropy of formation of the investigated dendrimer was evaluated at T = 298.15 K. The obtained thermodynamic properties of the studied hybrid dendrimer were compared and discussed with the literature data for some of the first-generation organosilicon and pyridylphenylene dendrimers.

Selective Activation of Estrogen Receptor α Activation Function-1 Is Sufficient to Prevent Obesity, Steatosis, and Insulin Resistance in Mouse.

Estrogen receptor α (ERα) regulates gene transcription through two activation functions (ERα-AF1 and ERα-AF2). We recently found that the protection conferred by 17ß-estradiol against obesity and insulin resistance requires ERα-AF2 but not ERα-AF1. However, the interplay between the two ERα-AFs is poorly understood in vivo and the metabolic influence of a specific ERα-AF1 action remains to be explored. To this end, wild-type, ERα-deficient, or ERα-AF1-deficient ovariectomized female mice were fed a high-fat diet and concomitantly administered with vehicle or tamoxifen, a selective ER modulator that acts as a ERα-AF1 agonist/ERα-AF2 antagonist. In ovariectomized wild-type mice, tamoxifen significantly reduced food intake and totally prevented adiposity, insulin resistance, and steatosis. These effects were abolished in ERα-deficient and ERα-AF1-deficient mice, revealing the specific role of ERα-AF1 activation. Finally, hepatic gene expression changes elicited by tamoxifen in wild-type mice were abrogated in ERα-AF1-deficient mice. The combination of pharmacologic and transgenic approaches thus indicates that selective ERα-AF1 activation by tamoxifen is sufficient to elicit metabolic protection, contrasting with the specific requirement of ERα-AF2 in the metabolic actions of 17ß-estradiol. This redundancy in the ability of the two ERα-AFs to separately mediate metabolic prevention strikingly contrasts with the contribution of both ERα-AFs in breast cancer proliferation, shedding new light on the therapeutic potential of selective ER modulation.

Two-level delivery systems based on CaCO3 cores for oral administration of therapeutic peptides.

Two-level systems for oral delivery of therapeutic peptides were developed; the carriers consist of CaCO3 cores included into alginate granules. Such systems were first used for the delivery of low molecular weight drugs. It was shown that efficiency of encapsulation of peptides depends on their pI value, hydrophobicity, characteristics of the compounds used for doping CaCO3 cores, their surface potential and the techniques employed for loading peptides into the first-level carriers. Doping CaCO3 cores with dextran sulphate save their viability compared to the pristine CaCO3 cores, but ensures delivery of the desired quantity of peptide when using a smaller amount of delivery systems. Introducing the inhibitor of peptidases leads to an increase in the concentration of peptide in rat blood after intragastric administration of the developed delivery systems. Scanning electron microscopy and energy-dispersive X-ray spectroscopy demonstrated the presence of fragments of destructed first-level carriers in blood and plasma of experimental animals.

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.

Temporal Release, Paracrine and Endocrine Actions of Ovine Conceptus-Derived Interferon-Tau During Early Pregnancy.

The antiviral activity of interferon (IFN) increases in uterine vein serum (UVS) during early pregnancy in sheep. This antiviral activity in UVS collected on Day 15 of pregnancy is blocked by anti-IFN-tau (anti-IFNT) antibodies. Conceptus-derived IFNT was hypothesized to induce IFN-stimulated gene (ISG) expression in endometrium and extrauterine tissues during pregnancy. To test this hypothesis, blood was collected from ewes on Days 12-16 of the estrous cycle or pregnancy. Serum progesterone was >1.7 ng/ml in pregnant (P) and nonpregnant (NP) ewes until Day 13, then declined to <0.6 ng/ml by Day 15 in NP ewes. A validated IFNT radioimmunoassay detected IFNT in uterine flushings (UFs) on Days 13-16 and in UVS on Days 15-16 of pregnancy. IFNT detection in UF correlated with paracrine induction of ISGs in the endometrium and occurred prior to the inhibition of estrogen receptor 1 and oxytocin receptor expression in uterine epithelia on Day 14 of pregnancy. Induction of ISG mRNAs in corpus luteum (CL) and liver tissue occurred by Day 14 and in peripheral blood mononuclear cells by Day 15 in P ewes. Expression of mRNAs for IFN signal transducers and ISGs were greater in the CL of P than that of NP ewes on Day 14. It is concluded that: 1) paracrine actions of IFNT coincide with detection of IFNT in UF; 2) endocrine action of IFNT ensues through induction of ISGs in peripheral tissues; and 3) IFNT can be detected in UVS, but not until Days 15-16 of pregnancy, which may be limited by the sensitivity of the IFNT radioimmunoassay.

Lattice-Modulated Phase Transition Coupled with Redox-Isomeric Interconversion of o-Semiquinone-Catecholato into Bis(o-semiquinonato) Cobalt Complexes.

Two redox-isomeric (valence tautomeric) complexes (2,2'-bpy)Co(3,6-DBSQ)2 (1) and (1,10-phen)Co(3,6-DBSQ)2 (2) (where 2,2'-bpy = 2,2'-dipyridine; 1,10-phen = 1,10-phenanthroline; 3,6-DBSQ = 3,6-di-tert-butyl-benzosemiquinone-1,2) reveal phase transitions that accompany redox-isomeric interconversions of semiquinone-catecholato isomer into a bis-(semiquinonato) one. Phase transitions differ one from another by thermodynamic parameters (transition temperature and interval, enthalpy, and entropy). Complexes 1 and 2 have the same crystal system and space group, and they form solid solutions with any molar ratio. The number of solid solutions with the molar ratios of 2:1, 1:1, 1:2, 1:4, 1:8, and 1:16 of 1 per 2, respectively, were obtained. Product with 1:1 ratio was studied by precise calorimetry, by variable-temperature magnetic susceptibility, and by X-ray structural analysis. All solid solutions were investigated by means of differential scanning calorimetry. Each solid solution possesses phase transition whose parameters depend on its composition. Transition temperature and enthalpy gradually grow with increasing of molar fraction of 1. The diagram "enthalpy-composition" is linear, whereas phase diagram "transition temperature-composition" is the bent-up arc.

Standard Thermodynamic Functions of Tripeptides N-Formyl-l-methionyl-l-leucyl-l-phenylalaninol and N-Formyl-l-methionyl-l-leucyl-l-phenylalanine Methyl Ester.

The heat capacities of tripeptides N-formyl-l-methionyl-l-leucyl-l-phenylalaninol (N-f-MLF-OH) and N-formyl-l-methionyl-l-leucyl-l-phenylalanine methyl ester (N-f-MLF-OMe) were measured by precision adiabatic vacuum calorimetry over the temperature range from T = (6 to 350) K. The tripeptides were stable over this temperature range, and no phase change, transformation, association, or thermal decomposition was observed. The standard thermodynamic functions: molar heat capacity Cp,m, enthalpy H(T) - H(0), entropy S(T), and Gibbs energy G(T) - H(0) of peptides were calculated over the range from T = (0 to 350) K. The low-temperature (T ≤ 50 K) heat capacities dependencies were analyzed using the Debye's and the multifractal theories. The standard entropies of formation of peptides at T = 298.15 K were calculated.

Symptoms and quality of life in adults with cystic fibrosis: A cross-sectional analysis of the InSPIRe:CF trial.

BACKGROUND: People living with cystic fibrosis (CF) experience a high symptom burden. Due to the changing landscape of CF in the era of modulator therapy, we sought to examine the epidemiology of symptoms and their association with quality of life, to help CF clinicians improve symptom screening in clinic. METHODS: Using baseline data from a trial of specialist palliative care in adults with CF, we examined symptom prevalence, distress, and association with quality of life (measured with the Functional Assessment of Chronic Illness Therapy Total Score). RESULTS: Among 262 participants, median age was 33, and 78% were on modulator therapy. The most common symptoms were lack of energy (n = 194, 74%) and cough (190, 73%), whereas the most distressing were difficulty sleeping (range 0-4, mean 2.19, SD 1.15) and pain (mean 2.04, SD 1.1). The symptoms that impaired quality of life the most were extrapulmonary: lack of energy (average quality of life score -29.8, 95% CI -36.8 to -22.8), feeling sad (-29.8, 95% CI -35.6 to -23.9) and worrying (-28.7, 95% CI -34.9 to -22.5). CONCLUSIONS: The symptoms that were associated with the lowest quality of life were extrapulmonary. CF clinicians may consider screening for common symptoms that affect quality of life the most (lack of energy, worrying, difficulty sleeping, feeling irritable, pain, and shortness of breath). These symptoms may identify people living with CF who are most at risk for a decreased quality of life and may benefit from additional support.

Criteria for Enrollment of Patients With COPD in Palliative Care Trials: A Systematic Review.

CONTEXT: Use of palliative care interventions in chronic obstructive pulmonary disease (COPD) has increased in recent years and inclusion criteria used to identify patients with COPD appropriate for palliative care vary widely. We evaluated the inclusion criteria to identify ways to improve enrollment opportunities for patients with COPD. OBJECTIVES: To determine inclusion criteria used to select patients with COPD for palliative care trials. METHODS: A systematic review was conducted to determine criteria used to select patients with COPD for palliative care randomized controlled trials. A narrative synthesis was conducted for all trials. RESULTS: Inclusion criteria were highly heterogeneous. Most studies (n = 11, 79%) used a combination of criteria to identify patients with COPD. Commonly used criteria included hospitalization for an acute exacerbation of COPD (n = 8, 57%), home supplemental oxygen use (n = 8, 57%), and spirometry values confirming COPD (n = 6, 43%). Three studies (21.4%) used Modified Medical Research Council score and two studies (21%) used physician prognosis or a performance scale. CONCLUSION: The most common criteria, a hospitalization for acute exacerbation of COPD or supplemental oxygen use at home, both have the benefit of selecting patients who have a higher symptom burden or higher healthcare utilization who might therefore benefit more from palliative care. By describing the landscape and variability of previously used inclusion criteria, this article serves as a resource for clinicians and researchers. Developing a consistent set of inclusion criteria in the future would help generate generalizable results that can be translated into clinical practice to improve the lives of patients with COPD. PROSPERO REGISTRATION NUMBER: CRD42022306752.

Pregnancy-associated genes contribute to antiluteolytic mechanisms in ovine corpus luteum.

The hypothesis that ovine luteal gene expression differs due to pregnancy status and day of estrous cycle was tested. RNA was isolated from corpora lutea (CL) on days 12 and 14 of the estrous cycle (NP) or pregnancy (P) and analyzed with the Affymetrix bovine microarray. RNA also was isolated from luteal cells on day 10 of estrous cycle that were cultured for 24 h with luteolytic hormones (OXT and PGF) and secretory products of the conceptus (IFNT and PGE2). Differential gene expression (>1.5-fold, P < 0.05) was confirmed using semiquantitative real-time PCR. Serum progesterone concentrations decreased from day 12 to day 15 in NP ewes (P < 0.05) reflecting luteolysis and remained >1.7 ng/ml in P ewes reflecting rescue of the CL. Early luteolysis (days 12-14) was associated with differential expression of 683 genes in the CL, including upregulation of SERPINE1 and THBS1. Pregnancy on day 12 (55 genes) and 14 (734 genes) also was associated with differential expression of genes in the CL, many of which were ISGs (i.e., ISG15, MX1) that were induced when culturing luteal cells with IFNT, but not PGE2. Finally, many genes, such as PTX3, IL6, VEGF, and LHR, were stabilized during pregnancy and downregulated during the estrous cycle and in response to culture of luteal cells with luteolytic hormones. In conclusion, pregnancy circumvents luteolytic pathways and activates or stabilizes genes associated with interferon, chemokine, cell adhesion, cytoskeletal, and angiogenic pathways in the CL.

Endocrine delivery of interferon tau protects the corpus luteum from prostaglandin F2 alpha-induced luteolysis in ewes.

Paracrine release of ovine interferon tau (oIFNT) from the conceptus alters release of endometrial prostaglandin F2 alpha (PGF) and prevents luteolysis. Endocrine release of oIFNT into the uterine vein occurs by Day 15 of pregnancy and may impart resistance of the corpus luteum (CL) to PGF. It was hypothesized that infusion of recombinant oIFNT (roIFNT) into the uterine or jugular veins on Day 10 of the estrous cycle would protect the CL against exogenous PGF-induced luteolysis. Osmotic pumps were surgically installed in 24 ewes to deliver bovine serum albumin (BSA; n = 12) or roIFNT (200 µg/day; n = 12) for 24 h into the uterine vein. Six ewes in each treatment group received a single injection of PGF (4 mg/58 kg body weight) 12 h after pump installation. In a second experiment, BSA or roIFNT was delivered at 20 or 200 µg/day into the uterine vein or 200 µg/day into the jugular vein for 72 h in 30 ewes. One half of these ewes received an injection of PGF 24 h after pump installation. Concentrations of progesterone in serum declined in BSA-treated ewes injected with PGF, but were sustained in all ewes infused with 20 µg/day of roIFNT into the uterine vein and 200 µg of roIFNT into the jugular vein followed 24 h later with injection of PGF. All concentrations of roIFNT and modes of delivery (uterine or jugular vein) increased luteal concentrations of IFN-stimulated gene (i.e., ISG15) mRNA. Infusion of 200 µg of IFNT over 24 h induced greater mRNA concentrations for cell survival genes, such as BCL2-like 1 (BCL2L1 or Bcl-xL), serine/threonine kinase (AKT), and X-linked inhibitor of apoptosis (XIAP) and decreased prostaglandin F receptor (PTGFR) mRNA concentrations, when compared to controls. It is concluded that endocrine delivery of roIFNT, regardless of route (uterine or jugular vein), effectively protects CL from the luteolytic actions of PGF by mechanisms that involve ISGs and stabilization of cell survival genes.

Vasa, Piwi, and Pl10 Expression during Sexual Maturation and Asexual Reproduction in the Annelid Pristina longiseta.

Naidids are tiny, transparent freshwater oligochaetes, which are well known for their ability to propagate asexually. Despite the fact that sexually mature individuals and cocoons with embryos are sometimes found in nature, in long-period laboratory cultures, worms reproduce agametically only. In this paper, we showed, for the first time, the expression of Vasa, Piwi, and Pl10 homologs in mature Pristina longiseta worms with well-developed reproductive system structures and germ cells. Although the animals have been propagated asexually by paratomic fission for over 20 years in our lab, some individuals become sexualized under standard conditions for our laboratory culture and demonstrate various stages of maturation. The fully matured animals developed a complete set of sexual apparatus including spermatheca, atrium, seminal vesicles, and ovisac. They also had a clitellum and were able to form cocoons. The cues for the initiation of sexual maturation are still unknown for P. longiseta; nevertheless, our data suggest that the laboratory strain of P. longiseta maintains the ability to become fully sexually mature and to establish germline products even after a long period of agametic reproduction. On the other hand, many of the sexualized worms formed a fission zone and continued to reproduce asexually. Thus, in this species, the processes of asexual reproduction and sexual maturation do not preclude each other, and Vasa, Piwi, and Pl10 homologs are expressed in both somatic and germline tissue including the posterior growth zone, fission zone, nervous system, germline cells, and gametes.