ITGAV Promotes the Progression of Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) refers to the malignancy of squamous cells in the head and neck region. Ranked as the seventh most common cancer worldwide, HNSCC has a very low survival rate, highlighting the importance of finding therapeutic targets for the disease. Integrins are cell surface receptors that play a crucial role in mediating cellular interactions with the extracellular matrix (ECM). Within this protein family, Integrin αV (ITGAV) has received attention for its important functional role in cancer progression. In this study, we first demonstrated the upregulation of ITGAV expression in HNSCC, with higher ITGAV expression levels correlating with significantly lower overall survival, based on TCGA (the Cancer Genome Atlas) and GEO datasets. Subsequent in vitro analyses revealed an overexpression of ITGAV in highly invasive HNSCC cell lines UM1 and UMSCC-5 in comparison to low invasive HNSCC cell lines UM2 and UMSCC-6. In addition, knockdown of ITGAV significantly inhibited the migration, invasion, viability, and colony formation of HNSCC cells. In addition, chromatin immunoprecipitation (ChIP) assays indicated that SOX11 bound to the promoter of ITGAV gene, and SOX11 knockdown resulted in decreased ITGAV expression in HNSCC cells. In conclusion, our studies suggest that ITGAV promotes the progression of HNSCC cells and may be regulated by SOX11 in HNSCC cells.

Structures and mechanisms of the Arabidopsis cytokinin transporter AZG1.

Cytokinins are essential for plant growth and development, and their tissue distributions are regulated by transmembrane transport. Recent studies have revealed that members of the 'Aza-Guanine Resistant' (AZG) protein family from Arabidopsis thaliana can mediate cytokinin uptake in roots. Here we present 2.7 to 3.3 Å cryo-electron microscopy structures of Arabidopsis AZG1 in the apo state and in complex with its substrates trans-zeatin (tZ), 6-benzyleaminopurine (6-BAP) or kinetin. AZG1 forms a homodimer and each subunit shares a similar topology and domain arrangement with the proteins of the nucleobase/ascorbate transporter (NAT) family. These structures, along with functional analyses, reveal the molecular basis for cytokinin recognition. Comparison of the AZG1 structures determined in inward-facing conformations and predicted by AlphaFold2 in the occluded conformation allowed us to propose that AZG1 may carry cytokinins across the membrane through an elevator mechanism.

A biosensing array for multiplex clinical evaluation of glucose, creatinine, and uric acid.

The multiplex and simultaneous determination of blood glucose, creatinine and uric acid is essential for the early screening of chronic diseases or regular disease monitoring. Here, we report for the first time a biosensing array for the multiplex and simultaneous determination of plasma glucose, creatinine and uric acid. The sensing electrodes are fabricated on a PET surface, including three working electrodes, one reference electrode, and one counter electrode. Each specific enzyme is immobilized on its corresponding working electrode. The biosensing array can exhibit high sensitivity and selectivity for the simultaneous determination of blood glucose, creatinine and uric acid in real blood samples, and the measurement results are accurate and consistent with those from the clinical biochemistry analyzer in the hospital. It is expected that this work could provide new avenues for the fundamental study of biosensing device construction, as well as practical applications of the detection of biomarkers in chronic diseases.

The efficacy of medial meniscal posterior Root tear Repair with or without high tibial osteotomy: a systematic review.

BACKGROUND: Medial meniscal posterior root tear (MMPRTs) is a common lesion of the knee joint, and repair surgery is a well-established treatment option. However, patients with obvious varus alignment are at an increased risk for MMPRT and can suffer from a greater degree of medial meniscus extrusion, which leads to the development of osteoarthritis following repair. The efficacy of high tibial osteotomy (HTO) as a means of correcting this malformation, and its potential benefits for MMPRT repair, remains unclear. PURPOSE: To explore whether HTO influenced the outcome of MMPRT repair in clinical scores and radiological findings. STUDY DESIGN: Systematic review. METHODS: According to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines, we searched PubMed, Embase, Web of Science, and the Cochrane Library databases for studies reporting the outcomes of MMPRT repair and extracted data about characteristics of patients, clinical functional scores and radiologic outcomes. One reviewer extracted the data and 2 reviewers assessed the risk of bias and performed a synthesis of the evidence. Articles were eligible if they reported the results of MMPRT repair with exact mechanical axis (registered in the International Prospective Register of Systematic Reviews, CRD42021292057). RESULTS: Fifteen studies with 625 cases of high methodological quality were identified. Eleven studies were assigned to the MMPRT repair group (M) with 478 cases performing MMPRT repair only, and others belonged to the MMPRT repair and HTO group (M and T) performing HTO and MMPRT repair. Most of the studies had significantly improved clinical outcome scores, especially in M groups. And the radiologic outcomes showed that the osteoarthritis deteriorated in both groups with similar degree in about 2-year follow-up. CONCLUSION: HTO is a useful supplement in treating MMPRT patients with severe osteoarthritis and the clinical and radiological outcomes were similar with MMPRT repair alone. Which would be better for patients' prognosis generally, performing MMPRT repair alone or a combination of HTO and MMPRT repair, was still controversial. We suggested taking K-L grade into account. Large-scale randomized control studies were called for in the future to help make better clinical decisions. LEVEL OF EVIDENCE: III.

Minimizing Cross-Reactivity for the Chemiluminescent Lateral Flow Immunoassay of Cardiac Troponin I Based on PEGylation of Gold Nanoparticles.

Lateral flow immunoassays (LFIAs) have been employed extensively for the rapid, accurate, and portable detection of protein biomarkers in healthcare. However, the cross-reactivity, especially in the multiplexed detection, leads to false-positive errors that would further limit their practical applications. In this work, we report a highly sensitive and accurate chemiluminescent LFIA based on the synthesis of the Au nanoparticle-antibody-horseradish peroxidase-polyethylene glycol conjugate for detecting cardiac troponin I (cTnI), a major biomarker of acute myocardial infarction. Due to the presence of polyethylene glycol, the accuracy of the LFIA was improved significantly from a clear false positive signal to the absence of a false positive signal. In addition, the device exhibited a highly sensitive detection of cTnI in the concentration range of 1-90 ng mL-1, and the detection limit can be as low as 10 pg mL-1. The method further enabled the multiplex detection of cTnI and myoglobin successfully. It is anticipated that this work may open new paradigms for the development of a variety of lateral flow devices with high sensitivity and accuracy and further lead to widespread practical applications in clinical diagnosis.

Structures of the human Wilson disease copper transporter ATP7B.

The P-type ATPase ATP7B exports cytosolic copper and plays an essential role in the regulation of cellular copper homeostasis. Mutants of ATP7B cause Wilson disease (WD), an autosomal recessive disorder of copper metabolism. Here, we present cryoelectron microscopy (cryo-EM) structures of human ATP7B in the E1 state in the apo, the putative copper-bound, and the putative cisplatin-bound forms. In ATP7B, the N-terminal sixth metal-binding domain (MBD6) binds at the cytosolic copper entry site of the transmembrane domain (TMD), facilitating the delivery of copper from the MBD6 to the TMD. The sulfur-containing residues in the TMD of ATP7B mark the copper transport pathway. By comparing structures of the E1 state human ATP7B and E2-Pi state frog ATP7B, we propose the ATP-driving copper transport model of ATP7B. These structures not only advance our understanding of the mechanisms of ATP7B-mediated copper export but can also guide the development of therapeutics for the treatment of WD.

Structural insights into angiotensin receptor signaling modulation by balanced and biased agonists.

The peptide hormone angiotensin II regulates blood pressure mainly through the type 1 angiotensin II receptor AT1 R and its downstream signaling proteins Gq and ß-arrestin. AT1 R blockers, clinically used as antihypertensive drugs, inhibit both signaling pathways, whereas AT1 R ß-arrestin-biased agonists have shown great potential for the treatment of acute heart failure. Here, we present a cryo-electron microscopy (cryo-EM) structure of the human AT1 R in complex with a balanced agonist, Sar1 -AngII, and Gq protein at 2.9 Å resolution. This structure, together with extensive functional assays and computational modeling, reveals the molecular mechanisms for AT1 R signaling modulation and suggests that a major hydrogen bond network (MHN) inside the receptor serves as a key regulator of AT1 R signal transduction from the ligand-binding pocket to both Gq and ß-arrestin pathways. Specifically, we found that the MHN mutations N1113.35 A and N2947.45 A induce biased signaling to Gq and ß-arrestin, respectively. These insights should facilitate AT1 R structure-based drug discovery for the treatment of cardiovascular diseases.

Clinicopathological Features of Kidney Injury Related to Immune Checkpoint Inhibitors: A Systematic Review.

(1) Background: Despite increasing recognition of immune checkpoint inhibitors (ICIs) and kidney immune-related adverse events (IRAEs), no large-sample studies have assessed the pathological characteristics and outcomes of biopsy-proven kidney IRAEs. (2) Methods: We comprehensively searched PubMed, Embase, Web of Science, and Cochrane for case reports, case series, and cohort studies for patients with biopsy-proven kidney IRAEs. All data were used to describe pathological characteristics and outcomes, and individual-level data from case reports and case series were pooled to analyze risk factors associated with different pathologies and prognoses. (3) Results: In total, 384 patients from 127 studies were enrolled. Most patients were treated with PD-1/PD-L1 inhibitors (76%), and 95% presented with acute kidney disease (AKD). Acute tubulointerstitial nephritis/acute interstitial nephritis (ATIN/AIN) was the most common pathologic type (72%). Most patients (89%) received steroid therapy, and 14% (42/292) required RRT. Among AKD patients, 17% (48/287) had no kidney recovery. Analyses of pooled individual-level data from 221 patients revealed that male sex, older age, and proton pump inhibitor (PPI) exposure were associated with ICI-associated ATIN/AIN. Patients with glomerular injury had an increased risk of tumor progression (OR 2.975; 95% CI, 1.176, 7.527; p = 0.021), and ATIN/AIN posed a decreased risk of death (OR 0.164; 95% CI, 0.057, 0.473; p = 0.001). (4) Conclusions: We provide the first systematic review of biopsy-proven ICI-kidney IRAEs of interest to clinicians. Oncologists and nephrologists should consider obtaining a kidney biopsy when clinically indicated.

Structural mechanisms of TRPV2 modulation by endogenous and exogenous ligands.

The transient receptor potential vanilloid 2 (TRPV2) ion channel is a polymodal receptor widely involved in many physiological and pathological processes. Despite many TRPV2 modulators being identified, whether and how TRPV2 is regulated by endogenous lipids remains elusive. Here, we report an endogenous cholesterol molecule inside the vanilloid binding pocket (VBP) of TRPV2, with a 'head down, tail up' configuration, resolved at 3.2 Å using cryo-EM. Cholesterol binding antagonizes ligand activation of TRPV2, which is removed from VBP by methyl-ß-cyclodextrin (MßCD) as resolved at 2.9 Å. We also observed that estradiol (E2) potentiated TRPV2 activation by 2-aminoethoxydiphenyl borate (2-APB), a classic tool compound for TRP channels. Our cryo-EM structures (resolved at 2.8-3.3 Å) further suggest how E2 disturbed cholesterol binding and how 2-APB bound within the VBP with E2 or without both E2 and endogenous cholesterol, respectively. Therefore, our study has established the structural basis for ligand recognition of the inhibitory endogenous cholesterol and excitatory exogenous 2-APB in TRPV2.

Uric acid and creatinine biosensors with enhanced room-temperature storage stability by a multilayer enzyme matrix.

Uric acid and creatinine are essential biomarkers for many diseases, such as gout, hyperuricemia, kidney diseases and heart diseases. Electrochemical biosensors are promising candidates for detecting uric acid and creatinine. However, the sensors always suffer from low stability that would limit their practical applications. In this work, we report a new multilayer enzyme matrix to enhance the room-temperature storage stabilities of uric acid and creatinine biosensors significantly. The enzymes are first dropped on the electrode surface directly, then a layer of glutaraldehyde was deposited on the surface of the enzyme layer, and after that, another layer of a polyvinyl alcohol (PVA)/poly(ethylene glycol) (PEG) composite was further placed on the surface of the glutaraldehyde layer, with drying in between. The stabilities of uric acid and creatinine biosensors were enhanced significantly, and the sensors can maintain highly stable sensing performance for over 4 months with a storage at room temperature. It is anticipated that this work could open new avenues for the practical applications of the uric acid and creatinine biosensors.

Influence and Mechanism of a Multi-Scale Built Environment on the Leisure Activities of the Elderly: Evidence from Hefei City in China.

Built environment characteristics such as walkability, land use diversity, infrastructure accessibility and attractiveness may support or hinder the elderly's leisure activities, which in turn affects their health. Promoting the elderly's leisure activities through the creation of a positive built environment is of great relevance to healthy aging. In the context of the continuous increasing of aging in China, promoting leisure activities for the elderly through improving the built environment has become an essential issue in urban geography and urban planning. Based on the questionnaire survey data of the elderly in Hefei City, a multilevel ordered probit regression model was used to investigate the mechanism of the multi-scale built environment on leisure activities of the elderly. The results show that: (1) more than 60% of the elderly can carry out leisure activities more than seven times a week, more than 50% of the elderly have a duration of fewer than 30 min for each leisure activity, and there are significant spatial differences in the frequency and duration of their trips at multiple scales in city, community and residential district. (2) Residential quality and community-level land use mixture, the density of leisure facilities, proximity to high-level urban roads, community security, living in the old city, and individual characteristic variables such as age, education, and satisfaction with neighborhood interaction positively contribute to the leisure activities of the elderly. In contrast, the community activity participation and the location close to expressways and railway lines have a significantly negative impact on the leisure activities of the elderly. (3) The mechanism of interactions between multi-scale built environments on the leisure activities of the elderly is mainly summarized as the transmission effect and substitution effect. The transmission effect shows that the differences in the community-level built environment are primarily caused by the differences in the city-level built environment. In contrast, the substitution effect shows that the multi-scale built environment such as residential districts, communities, and cities jointly affect the leisure activities of the elderly. Based on the mechanism of the built environment at different scales, this study can provide theoretical references and planning implications to improve the built environment through planning means such as enhancing the walkability of streets, the accessibility of facilities and the scale of greenery in order to promote active leisure activities and improve the health of the elderly.

Mechanisms of helicase activated DNA end resection in bacteria.

DNA end resection mediated by the coordinated action of nuclease and helicase is a crucial step in initiating homologous recombination. The end-resection apparatus NurA nuclease and HerA helicase are present in both archaea and bacteria. Here, we report the cryo-electron microscopy structure of a bacterial HerA-NurA complex from Deinococcus radiodurans. The structure reveals a barrel-like hexameric HerA and a distinctive NurA dimer subcomplex, which has a unique extended N-terminal region (ENR) involved in bacterial NurA dimerization and activation. In addition to the long protruding linking loop and the C-terminal α helix of NurA, the flexible ENR is close to the HerA-NurA interface and divides the central channel of the DrNurA dimer into two halves, suggesting a possible mechanism of DNA end processing. In summary, this work provides new insights into the structure, assembly, and activation mechanisms of bacterial DNA end resection mediated by a minimal end-resection apparatus.

Voltage-gating and cytosolic Ca2+ activation mechanisms of Arabidopsis two-pore channel AtTPC1.

Arabidopsis thaliana two-pore channel AtTPC1 is a voltage-gated, Ca2+-modulated, nonselective cation channel that is localized in the vacuolar membrane and responsible for generating slow vacuolar (SV) current. Under depolarizing membrane potential, cytosolic Ca2+ activates AtTPC1 by binding at the EF-hand domain, whereas luminal Ca2+ inhibits the channel by stabilizing the voltage-sensing domain II (VSDII) in the resting state. Here, we present 2.8 to 3.3 Å cryoelectron microscopy (cryo-EM) structures of AtTPC1 in two conformations, one in closed conformation with unbound EF-hand domain and resting VSDII and the other in a partially open conformation with Ca2+-bound EF-hand domain and activated VSDII. Structural comparison between the two different conformations allows us to elucidate the structural mechanisms of voltage gating, cytosolic Ca2+ activation, and their coupling in AtTPC1. This study also provides structural insight into the general voltage-gating mechanism among voltage-gated ion channels.

Structural and functional basis of the selectivity filter as a gate in human TRPM2 channel.

Transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable cation channel, is gated by intracellular adenosine diphosphate ribose (ADPR), Ca2+, warm temperature, and oxidative stress. It is critically involved in physiological and pathological processes ranging from inflammation to stroke to neurodegeneration. At present, the channel's gating and ion permeation mechanisms, such as the location and identity of the selectivity filter, remain ambiguous. Here, we report the cryo-electron microscopy (cryo-EM) structure of human TRPM2 in nanodisc in the ligand-free state. Cryo-EM map-guided computational modeling and patch-clamp recording further identify a quadruple-residue motif as the ion selectivity filter, which adopts a restrictive conformation in the closed state and acts as a gate, profoundly contrasting with its widely open conformation in the Nematostella vectensis TRPM2. Our study reveals the gating of human TRPM2 by the filter and demonstrates the feasibility of using cryo-EM in conjunction with computational modeling and functional studies to garner structural information for intrinsically dynamic but functionally important domains.

Phosphorylation at Ser68 facilitates DCAF11-mediated ubiquitination and degradation of CENP-A during the cell cycle.

CENP-A (centromeric protein A), a histone H3 variant, specifies centromere identity and is essential to centromere maintenance. Little is known about how protein levels of CENP-A are controlled in mammalian cells. Here, we report that the phosphorylation of CENP-A Ser68 primes the ubiquitin-proteasome-mediated proteolysis of CENP-A during mitotic phase in human cultured cells. We identify two major polyubiquitination sites that are responsible for this phosphorylation-dependent degradation. Substituting the two residues, Lys49 and Lys124, with arginines abrogates proper CENP-A degradation and results in CENP-A mislocalization to non-centromeric regions. Furthermore, we find that DCAF11 (DDB1 and CUL4 associated factor 11/WDR23) is the E3 ligase that specifically mediates the observed polyubiquitination. Deletion of DCAF11 hampers CENP-A degradation and causes its mislocalization. We conclude that the Ser68 phosphorylation plays an important role in regulating cellular CENP-A homeostasis via DCAF11-mediated degradation to prevent ectopic localization of CENP-A during the cell cycle.

Safety and Efficacy of the Rechallenge of Immune Checkpoint Inhibitors After Immune-Related Adverse Events in Patients With Cancer: A Systemic Review and Meta-Analysis.

Introduction: Little evidence exists on the safety and efficacy of the rechallenge of immune checkpoint inhibitors (ICIs) after immune-related adverse events (irAEs) in patients with cancer. Methods: We searched PubMed, Web of Science, Embase, and Cochrane for articles on ICI rechallenge after irAEs for systemic review and meta-analysis. The outcomes included the incidence and associated factors for safety and objective response rate (ORR) and disease control rate (DCR) for efficacy. Results: A total of 789 ICI rechallenge cases from 18 cohort studies, 5 case series studies, and 54 case reports were included. The pooled incidence of all-grade and high-grade irAEs after rechallenge in patients with cancer was 34.2% and 11.7%, respectively. Compared with initial ICI treatment, rechallenge showed a higher incidence for all-grade irAEs (OR, 3.81; 95% CI, 2.15-6.74; p < 0.0001), but similar incidence for high-grade irAEs (p > 0.05). Types of initial irAEs (pneumonitis and global irAEs) and cancer (non-small cell lung cancer and multiple cancer) recapitulated these findings. Gastrointestinal irAEs and time interval between initial irAEs and ICI rechallenge were associated with higher recurrence of high-grade irAEs (p < 0.05), whereas initial anti-PD-1/PD-L1 antibodies were associated with a lower recurrence (p < 0.05). Anti-PD-1/PD-L1 antibodies rechallenge was associated with a lower all-grade irAE recurrence (p < 0.05). The pooled ORR and DCR after rechallenge were 43.1% and 71.9%, respectively, showing no significant difference compared with initial ICI treatment (p > 0.05). Conclusions: ICI rechallenge after irAEs showed lower safety and similar efficacy outcomes compared with initial ICI treatment. Systematic Review Registration: PROSPERO, identifier CRD42020191405.

Difference Between Medical and Nonmedical Students on Knowledge, Practice, and Attitude Towards the Human Papillomavirus Vaccine in China: a Cross-Sectional Study.

HPV vaccine can prevent HPV infection effectively. The college student's vaccination status is unclear in mainland China. We assessed the knowledge, practice, and attitude towards HPV vaccine and compared the differences between medical and nonmedical students. It was a cross-sectional study using self-administered anonymous questionnaires. Nine-hundred sixty full-time college students were recruited randomly at Peking University in China. The medical students had higher level of knowledge of HPV and its vaccine than the nonmedical students (p < 0.001). The vaccinated female students were 9.0%. The high-grade clinical students had a higher uptake rate than the nonmedical students (19.5 vs 8.6%, p < 0.05). Awareness of HPV (p < 0.01), awareness of the vaccine (p < 0.001), and vaccinated family members or friends (p < 0.001) were related to the nonmedical students' vaccination. Vaccinated family members or friends were significant predictor for students' vaccination status (p < 0.001). Medical students knew more about HPV and its vaccine than nonmedical students. Female students' vaccinated rate was low, and the high-grade clinical students had a higher uptake rate than the nonmedical students.

Prevalence of Kidney Injury and Associations with Critical Illness and Death in Patients with COVID-19.

BACKGROUND AND OBJECTIVES: Coronavirus disease 2019 is spreading rapidly across the world. This study aimed to assess the characteristics of kidney injury and its association with disease progression and death of patients with coronavirus disease 2019. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This is a retrospective study. Two representative cohorts were included. Cohort 1 involved severe and critical patients with coronavirus disease 2019 from Wuhan, China. Cohort 2 was all patients with coronavirus disease 2019 in Shenzhen city (Guangdong province, China). Any kidney injury was defined as the presence of any of the following: hematuria, proteinuria, in-hospital AKI, or prehospital AKI. AKI was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) creatinine criteria. The primary outcome was death at the end of follow-up. The secondary outcome was progression to critical illness during the study period. RESULTS: A total of 555 patients were enrolled; 42% of the cases (229 of 549) were detected with any kidney injury, 33% of the cases (174 of 520) were detected with proteinuria, 22% of the cases (112 of 520) were detected with hematuria, and 6% of the cases (29 of 520) were detected with AKI. Of the 29 patients with AKI, 21 cases were recognized as in-hospital AKI, and eight were recognized as prehospital AKI. Altogether, 27 (5%) patients died at the end of follow-up. The death rate was 11% (20 of 174) in patients with proteinuria, 16% (18 of 112) in patients with hematuria, and 41% (12 of 29) in the AKI settings. Multivariable Cox regression analysis showed that proteinuria (hazard ratio, 4.42; 95% confidence interval, 1.22 to 15.94), hematuria (hazard ratio, 4.71; 95% confidence interval, 1.61 to 13.81), and in-hospital AKI (hazard ratio, 6.84; 95% confidence interval, 2.42 to 19.31) were associated with death. Among the 520 patients with noncritical illness at admission, proteinuria (hazard ratio, 2.61; 95% confidence interval, 1.22 to 5.56) and hematuria (hazard ratio, 2.50; 95% confidence interval, 1.23 to 5.08) were found to be associated with progression to critical illness during the study period. CONCLUSIONS: Kidney injury is common in coronavirus disease 2019, and it is associated with poor clinical outcomes. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_09_18_CJN04780420.mp3.

Morphology and quantification of fungal growth in residential dust and carpets.

Mold growth indoors is associated with negative human health effects, and this growth is limited by moisture availability. Dust deposited in carpet is an important source of human exposure due to potential elevated resuspension compared to hard floors. However, we need an improved understanding of fungal growth in dust and carpet to better estimate human exposure. The goal of this study was to compare fungal growth quantity and morphology in residential carpet under different environmental conditions, including equilibrium relative humidity (ERH) (50%, 85%, 90%, 95%, 100%), carpet fiber material (nylon, olefin, wool) and presence/absence of dust. We analyzed incubated carpet and dust samples from three Ohio homes for total fungal DNA, fungal allergen Alt a 1, and fungal morphology. Dust presence and elevated ERH (≥85%) were the most important variables that increased fungal growth. Elevated ERH increased mean fungal DNA concentration (P < 0.0001), for instance by approximately 1000 times at 100% compared to 50% ERH after two weeks. Microscopy also revealed more fungal growth at higher ERH. Fungal concentrations were up to 100 times higher in samples containing house dust compared to no dust. For fiber type, olefin had the least total fungal growth, and nylon had the most total fungi and A. alternata growth in unaltered dust. Increased ERH conditions were associated with increased Alt a 1 allergen concentration. The results of this study demonstrate that ERH, presence/absence of house dust, and carpet fiber type influence fungal growth and allergen production in residential carpet, which has implications for human exposure.