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Amphipathic peptides with amino acids arranged in alternating patterns of hydrophobic and hydrophilic residues efficiently self-assemble into ß-sheet bilayer nanoribbons. Hydrophobic side chain functionality is effectively buried in the interior of the putative bilayer of these nanoribbons. This study investigates consequences on self-assembly of increasing the surface area of aromatic side chain groups that reside in the hydrophobic core of nanoribbons derived from Ac-(XKXE)2 -NH2 peptides (X = hydrophobic residue). A series of Ac-(XKXE)2 -NH2 peptides incorporating aromatic amino acids of increasing molecular volume and steric profile (X = phenylalanine [Phe], homophenylalanine [Hph], tryptophan [Trp], 1-naphthylalanine [1-Nal], 2-naphthylalanine [2-Nal], or biphenylalanine [Bip]) were assessed to determine substitution effects on self-assembly propensity and on morphology of the resulting nanoribbon structures. Additional studies were conducted to determine the effects of incorporating amino acids of differing steric profile in the hydrophobic core (Ac-X1 KFEFKFE-NH2 and Ac-(X1,5 KFE)-NH2 peptides, X = Trp or Bip). Spectroscopic analysis by circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy indicated ß-sheet formation for all variants. Self-assembly rate increased with peptide hydrophobicity; increased molecular volume of the hydrophobic side chain groups did not appear to induce kinetic penalties on self-assembly rates. Transmission electron microscopy (TEM) imaging indicated variation in fibril morphology as a function of amino acid in the X positions. This study confirms that hydrophobicity of amphipathic Ac-(XKXE)2 -NH2 peptides correlates to self-assembly propensity and that the hydrophobic core of the resulting nanoribbon bilayers has a significant capacity to accommodate sterically demanding functional groups. These findings provide insight that may be used to guide the exploitation of self-assembled amphipathic peptides as functional biomaterials.
Assuntos
Nanotubos de Carbono , Dicroísmo Circular , Interações Hidrofóbicas e Hidrofílicas , Peptídeos , Conformação Proteica em Folha beta , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
BACKGROUND: High-risk human papillomavirus (hrHPV) causes cervical cancer. In the United States, approximately 40% of women aged 14-59 years from all racial and ethnic groups are infected with HPV, and prevalence typically declines with age. However, American Indian (AI) women are insufficiently sampled to permit a population-specific estimate of hrHPV prevalence. METHODS: Vaginal swabs were self-collected by 698 AI women aged 21-65 years from a tribal community in the Great Plains. We estimated the population prevalence of hrHPV and identified predominant genotypes. RESULTS: The combined prevalence of hrHPV genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68 was 34.8%. HPV-51 (7.6%), HPV-58 (5.3%), HPV-52 (4.3%), HPV-18 (4.3%), and HPV-16 (3.9%) were most prevalent. hrHPV prevalence declined with age, from 42.2% in women aged 21-24 years to 27.9% in women aged 50-65 years. CONCLUSIONS: HPV-51 was the single most prevalent oncogenic genotype. The combined prevalence of hrHPV among AI women in our sample was high, particularly among women aged 50-65 years, for whom hrHPV prevalence was approximately triple that of other races. Cervical cancer screening efforts should be increased, particularly among women from the community aged 30 years and older.
Assuntos
Indígenas Norte-Americanos , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Adulto , Idoso , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Meio-Oeste dos Estados Unidos/epidemiologia , Papillomaviridae/genética , Infecções por Papillomavirus/etnologia , Infecções por Papillomavirus/virologia , PrevalênciaRESUMO
Opioid use disorder (OUD) and opioid overdoses are public health emergencies. In 2021, 80,000 opioid overdose associated deaths were reported in the United States. Despite the availability of treatment strategies, including medications for opioid use disorder (MOUD) and naloxone, opioid overdoses continue to increase at an alarming rate. Opioid vaccines are a novel approach to combat the growing crisis with several candidates recently entering human clinical trials. In this study, we investigated Qß bacteriophage virus-like particles (VLPs) as a vaccine platform for immunogenic display of oxycodone. A derivative of oxycodone was conjugated to pre-formed Qß VLPs using a sulfhydryl-amine reactive heterobifunctional crosslinker with high loading of oxycodone. In mice, intramuscular immunization with Qß-oxycodone elicited high-titer, high-avidity and long-lasting antibody responses. Qß-oxycodone was also immunogenic after storage at ambient room temperature for over two weeks, demonstrating that the vaccine is highly thermostable. In mice, immunization with Qß-oxycodone elicited antibodies that sequester oxycodone in the serum, an important mechanism for preventing the adverse effects of opioid activity. Finally, Qß-oxycodone is immunogenic in nonhuman primates, eliciting serum oxycodone antibodies after intramuscular immunization of rhesus macaques. These data establish Qß-oxycodone as a promising opioid vaccine candidate.
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Bacteriófagos , Overdose de Opiáceos , Transtornos Relacionados ao Uso de Opioides , Vacinas de Partículas Semelhantes a Vírus , Camundongos , Humanos , Animais , Oxicodona , Analgésicos Opioides , Macaca mulatta , Anticorpos , Transtornos Relacionados ao Uso de Opioides/prevenção & controleRESUMO
Vaginal dysbiosis is implicated in persistent HPV infection and cervical cancer. Yet, there is a paucity of data on the vaginal microbiome in Native American communities. Here, we aimed to elucidate the relationships between microbiome, HPV, sociodemographic and behavioral risk factors to better understand an increased cervical cancer risk in Native American women. In this pilot study, we recruited 31 participants (16 Native American, 15 non-Native women) in Northern Arizona and examined vaginal microbiota composition, HPV status, and immune mediators. We also assessed individuals' sociodemographic information, and physical, mental, sexual, and reproductive health. Overall, microbiota profiles were dominated by common Lactobacillus species (associated with vaginal health) or a mixture of bacterial vaginosis-associated bacteria. Only 44% of Native women exhibited Lactobacillus dominance, compared to 58% of non-Native women. Women with vaginal dysbiosis also had elevated vaginal pH and were more frequently infected with high-risk HPV. Furthermore, we observed associations of multiple people in a household, lower level of education, and high parity with vaginal dysbiosis and abundance of specific bacterial species. Finally, women with dysbiotic microbiota presented with elevated vaginal levels of proinflammatory cytokines. Altogether, these findings indicate an interplay between HPV, vaginal microbiota, and host defense, which may play a role in the cervical cancer disparity among Native American women. Future longitudinal studies are needed to determine the mechanistic role of vaginal microbiota in HPV persistence in the context of social determinants of health toward the long-term goal of reducing health disparities between non-Hispanic White and Native American populations.
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Amphipathic peptides composed of alternating hydrophobic and hydrophilic amino acids are a privileged class of peptide, which have a high propensity to self-assemble into ß-sheet fibrils. The Ac-(FKFE)2-NH2 peptide has been extensively studied and forms putative ß-sheet bilayer fibrils in which the hydrophobic Phe side chains are organized to a single face of each constituent sheet; upon bilayer formation, these hydrophobic benzyl groups are sequestered in the hydrophobic core of the resulting fibril. In order for the Phe side chains to be uniformly displayed on one face of Ac-(FKFE)2-NH2 ß-sheets, an antiparallel packing orientation in which one amino acid residue is unpaired must be adopted. Based on molecular models, we hypothesized that truncated seven amino acid derivatives of Ac-(FKFE)2-NH2 in which either the N-terminal Phe residue (Ac-KFEFKFE-NH2) or the C-terminal Glu residue (Ac-FKFEFKF-NH2) is eliminated should readily self-assemble into ß-sheet bilayers in which all hydrogen bond and hydrophobic/charge interactions are satisfied. We found, however, that these minute changes in peptide sequence have unanticipated and dramatic effects on the self-assembly of each peptide. Ac-FKFEFKF-NH2 self-assembled into fibrils with unique morphology relative to the parent peptide, whereas the Ac-KFEFKFE-NH2 peptide had a strongly reduced propensity to self-assemble, even failing to self-assemble altogether under some conditions. These findings provide significant insight into the effect of sequence length and strand registry as well as hydrophobicity and charge on the self-assembly of simple amphipathic peptides to illuminate the possibility of tuning self-assembly processes and the resulting structures with minute changes to peptide sequence.
Assuntos
Peptídeos , Estrutura Secundária de Proteína , Sequência de Aminoácidos , Aminoácidos/química , Interações Hidrofóbicas e Hidrofílicas , Peptídeos/químicaRESUMO
Amphipathic peptides have an increased propensity to self-assemble into amyloid-like ß-sheet fibrils when their primary sequence pattern consists of alternating hydrophobic and hydrophilic amino acids. These fibrils adopt a bilayer architecture composed of two ß-sheets laminated to bury the hydrophobic side chains of the ß-sheet in the bilayer interior, leaving the hydrophilic side chains exposed at the bilayer surface. In this study, the effects of altering the sequence pattern of amphipathic peptides from strictly alternating hydrophobic/hydrophilic repeats to more complex patterning of hydrophobic and hydrophilic residues on self-assembly of the resulting sequences is reported. Self-assembly of the Ac-(FKFE)2-NH2 peptide was compared to that of four related sequences with varied amino acid sequence patterning: Ac-(FK)2(FE)2-NH2, Ac-KEFFFFKE-NH2, Ac-(KFFE)2-NH2, and Ac-FFKEKEFF-NH2. The Ac-(FKFE)2-NH2 and Ac-(FK)2(FE)2-NH2 peptides effectively self-assembled at high (1.0 mM) and low (0.2 mM) concentrations (pH 3-4) into ß-sheet nanoribbons that were 8 and 4 nm wide, respectively. The Ac-KEFFFFKE-NH2 peptide failed to self-assemble at low concentration (pH 3-4), but self-assembled into distinct nanotapes that were ~20 nm in width at high concentration. Ac-(KFFE)2-NH2 and Ac-FFKEKEFF-NH2 failed to self-assemble into fibril/tape-like materials at either high or low concentration at pH 3-4, although Ac-FFKEKEFF-NH2 formed micelle-like aggregates at higher concentrations. At neutral pH, similar self-assembly behavior was observed for each peptide as was observed at acidic pH. An exception was the Ac-FFKEKEFF-NH2 peptide, which formed ~20 nm nanotapes at neutral pH. These results indicate that amino acid sequence patterns exert a profound influence on self-assembly propensity and morphology of the resulting materials even when the overall hydrophobicity or charge of the related peptides are identical. Sequence pattern variation can thus be exploited as a variable in the creation of novel materials composed of self-assembled peptides.
Assuntos
Nanofibras/química , Oligopeptídeos/química , Sequência de Aminoácidos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Nanofibras/ultraestrutura , Estrutura Secundária de Proteína , Tensoativos/química , TermodinâmicaRESUMO
The fungal disease Valley fever causes a significant medical and financial burden for affected people in the endemic region, and this burden is on the rise. Despite the medical importance of this disease, little is known about ecological factors that influence the geographic point sources of high abundance of the pathogens Coccidioides posadasii and C. immitis, such as competition with co-occurring soil microbes. These "hot spots", for instance, those in southern Arizona, are areas in which humans are at greater risk of being infected with the fungus due to consistent exposure. The aim of this study was to isolate native microbes from soils collected from Tucson, Arizona (endemic area for C. posadasii) and characterize their relationship (antagonistic, synergistic, or neutral) to the fungal pathogen with in vitro challenge assays. Secreted metabolites from the microbes were extracted and described using analytical techniques including high-performance liquid chromatography (HPLC) and mass spectrometry. Bacteria belonging to the genus Bacillus and fungi in the Fennellomyces and Ovatospora genera were shown to significantly decrease the growth of Coccidioides spp. In vitro. In contrast, other bacteria in the Brevibacillus genus, as well as one species of Bacillus bacteria, were shown to promote growth of Coccidioides when directly challenged. The metabolites secreted from the antagonistic bacteria were described using HPLC and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The microbes identified in this study as antagonists to Coccidioides and/or the metabolites they secrete have the potential to be used as natural biocontrol agents to limit the amount of fungal burden at geographic point sources, and therefore limit the potential for human infection.
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The COVID-19 pandemic, although a profound reminder of endured injustices by and the disparate impact of infectious diseases on Indigenous populations, has also served as an example of Indigenous strength and the ability to thrive anew. Many infectious diseases share common risk factors that are directly tied to the ongoing effects of colonisation. We provide historical context and case studies that illustrate both challenges and successes related to infectious disease mitigation in Indigenous populations in the USA and Canada. Infectious disease disparities, driven by persistent inequities in socioeconomic determinants of health, underscore the urgent need for action. We call on governments, public health leaders, industry representatives, and researchers to reject harmful research practices and to adopt a framework for achieving sustainable improvements in the health of Indigenous people that is both adequately resourced and grounded in respect for tribal sovereignty and Indigenous knowledge.
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COVID-19 , Doenças Transmissíveis , Humanos , Pandemias/prevenção & controle , COVID-19/epidemiologia , América do Norte/epidemiologia , Canadá/epidemiologia , Povos Indígenas , Doenças Transmissíveis/epidemiologiaRESUMO
The Many Hosts of Mycobacteria (MHM) meeting series brings together basic scientists, clinicians and veterinarians to promote robust discussion and dissemination of recent advances in our knowledge of numerous mycobacterial diseases, including human and bovine tuberculosis (TB), nontuberculous mycobacteria (NTM) infection, Hansen's disease (leprosy), Buruli ulcer and Johne's disease. The 9th MHM conference (MHM9) was held in July 2022 at The Ohio State University (OSU) and centered around the theme of "Confounders of Mycobacterial Disease." Confounders can and often do drive the transmission of mycobacterial diseases, as well as impact surveillance and treatment outcomes. Various confounders were presented and discussed at MHM9 including those that originate from the host (comorbidities and coinfections) as well as those arising from the environment (e.g., zoonotic exposures), economic inequality (e.g. healthcare disparities), stigma (a confounder of leprosy and TB for millennia), and historical neglect (a confounder in Native American Nations). This conference report summarizes select talks given at MHM9 highlighting recent research advances, as well as talks regarding the historic and ongoing impact of TB and other infectious diseases on Native American Nations, including those in Southwestern Alaska where the regional TB incidence rate is among the highest in the Western hemisphere.
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Coinfecção , Infecções por Mycobacterium não Tuberculosas , Mycobacterium tuberculosis , Tuberculose Bovina , Animais , Bovinos , Humanos , Micobactérias não Tuberculosas , Infecções por Mycobacterium não Tuberculosas/microbiologiaRESUMO
Cervical cancer is the 4th most common type of cancer in women world-wide. Many factors play a role in cervical cancer development/progression that include genetics, social behaviors, social determinants of health, and even the microbiome. The prevalence of HPV infections and cervical cancer is high and often understudied among Native American communities. While effective HPV vaccines exist, less than 60% of 13- to 17-year-olds in the general population are up to date on their HPV vaccination as of 2020. Vaccination rates are higher among Native American adolescents, approximately 85% for females and 60% for males in the same age group. Unfortunately, the burden of cervical cancer remains high in many Native American populations. In this paper, we will discuss HPV infection, vaccination and the cervicovaginal microbiome with a Native American perspective. We will also provide insight into new strategies for developing novel methods and therapeutics to prevent HPV infections and limit HPV persistence and progression to cervical cancer in all populations.
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Vacinas contra a AIDS , Vacinas contra Influenza , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Vacinas contra Vírus Sincicial Respiratório , Vacinas contra a SAIDS , Neoplasias do Colo do Útero , Adolescente , Vacina BCG , Vacina contra Difteria, Tétano e Coqueluche , Feminino , Humanos , Masculino , Vacina contra Sarampo-Caxumba-Rubéola , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/uso terapêutico , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Indígena Americano ou Nativo do AlascaRESUMO
Despite a global and nationwide decrease, Native Americans continue to experience high rates of cancer morbidity and mortality. Vaccination is one approach to decrease cancer incidence such as the case of cervical cancer. However, the availability of vaccines does not guarantee uptake, as evident in the Coronavirus 2019 pandemic. Therefore, as we consider current and future cancer vaccines, there are certain considerations to be mindful of to increase uptake among Native Americans such as the incidence of disease, social determinants of health, vaccine hesitancy, and historical exclusion in clinical trials. This paper primarily focuses on human papillomavirus (HPV) and potential vaccines for Native Americans. However, we also aim to inform researchers on factors that influence Native American choices surrounding vaccination and interventions including cancer therapies. We begin by providing an overview of the historical distrust and trauma Native Americans experience, both past and present. In addition, we offer guidance and considerations when engaging with sovereign Tribal Nations in vaccine development and clinical trials in order to increase trust and encourage vaccine uptake.
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Vacinas Anticâncer , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Infecções por Papillomavirus/prevenção & controle , Neoplasias do Colo do Útero/prevenção & controle , Indígena Americano ou Nativo do AlascaRESUMO
American Indian and Alaska Native women had approximately twice the incidence of cervical cancer as white women. Preventive measures for cervical cancer rely on screening and HPV vaccination. However, vaccine series completion and catch-up vaccinations for eligible adults are low across all racial/ethnic groups. Therefore, the aim of this study was to identify gaps in knowledge and evaluate the attitudes toward HPV and the vaccine among AIANs with various levels of training in the STEM and health-related fields. A survey was used to collect data from audience members at two national conferences geared towards American Indian and Alaska Natives in health and STEM fields in September 2017. A vignette study was administered via a live electronic poll to test knowledge (true/false questions), attitudes, and to collect demographic information. Respondents self-identified as primarily American Indian and Alaska Native (74%), pursuing or completed a graduate degree (67%), and female (85%). Most respondents (86%) were aware of HPV-associated cancer in men. However, most (48-90%) answered incorrectly to detailed true/false statements about HPV and available vaccines. After educational information was provided, opinions collected via vignettes highlighted mainly positive attitudes toward vaccination; specifically, that vaccines are safe and all eligible community members should be vaccinated (75% and 84%, respectively). We observed that our respondents with higher educational attainment still lacked accurate knowledge pertaining to HPV and the vaccine. Overall, continued education about HPV and the vaccine is needed across all levels of education including American Indian and Alaska Native community members and health professionals.
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Aromatic amino acids have been shown to promote self-assembly of amyloid peptides, although the basis for this amyloid-inducing behavior is not understood. We adopted the amyloid-ß 16-22 peptide (Aß(16-22), Ac-KLVFFAE-NH(2)) as a model to study the role of aromatic amino acids in peptide self-assembly. Aß(16-22) contains two consecutive Phe residues (19 and 20) in which Phe 19 side chains form interstrand contacts in fibrils while Phe 20 side chains interact with the side chain of Va l18. The kinetic and thermodynamic effect of varying the hydrophobicity and aromaticity at positions 19 and 20 by mutation with Ala, Tyr, cyclohexylalanine (Cha), and pentafluorophenylalanine (F(5)-Phe) (order of hydrophobicity is Ala < Tyr < Phe < F(5)-Phe < Cha) was characterized. Ala and Tyr position 19 variants failed to undergo fibril formation at the peptide concentrations studied, but Cha and F(5)-Phe variants self-assembled at dramatically enhanced rates relative to wild-type. Cha mutation was thermodynamically stabilizing at position 20 (ΔΔG = -0.2 kcal mol(-1) relative to wild-type) and destabilizing at position 19 (ΔΔG = +0.2 kcal mol(-1)). Conversely, F(5)-Phe mutations were strongly stabilizing at both positions (ΔΔG = -1.3 kcal mol(-1) at 19, ΔΔG = -0.9 kcal mol(-1) at 20). The double Cha and F(5)-Phe mutants showed that the thermodynamic effects were additive (ΔΔG = 0 kcal mol(-1) for Cha 19,20 and -2.1 kcal mol(-1) for F(5)-Phe 19,20). These results indicate that sequence hydrophobicity alone does not dictate amyloid potential, but that aromatic, hydrophobic, and steric considerations collectively influence fibril formation.