MAdCAM-1 costimulation in the presence of retinoic acid and TGF-ß promotes HIV infection and differentiation of CD4+ T cells into CCR5+ TRM-like cells.

CD4+ tissue resident memory T cells (TRMs) are implicated in the formation of persistent HIV reservoirs that are established during the very early stages of infection. The tissue-specific factors that direct T cells to establish tissue residency are not well defined, nor are the factors that establish viral latency. We report that costimulation via MAdCAM-1 and retinoic acid (RA), two constituents of gut tissues, together with TGF-ß, promote the differentiation of CD4+ T cells into a distinct subset α4ß7+CD69+CD103+ TRM-like cells. Among the costimulatory ligands we evaluated, MAdCAM-1 was unique in its capacity to upregulate both CCR5 and CCR9. MAdCAM-1 costimulation rendered cells susceptible to HIV infection. Differentiation of TRM-like cells was reduced by MAdCAM-1 antagonists developed to treat inflammatory bowel diseases. These finding provide a framework to better understand the contribution of CD4+ TRMs to persistent viral reservoirs and HIV pathogenesis.

The V2 domain of HIV gp120 mimics an interaction between CD4 and integrin ⍺4ß7.

The CD4 receptor, by stabilizing TCR-MHC II interactions, plays a central role in adaptive immunity. It also serves as the HIV docking receptor. The HIV gp120 envelope protein binds directly to CD4. This interaction is a prerequisite for viral entry. gp120 also binds to ⍺4ß7, an integrin that is expressed on a subset of memory CD4+ T cells. HIV tropisms for CD4+ T cells and gut tissues are central features of HIV pathogenesis. We report that CD4 binds directly to ⍺4ß7 in a dynamic way, consistent with a cis regulatory interaction. The molecular details of this interaction are related to the way in which gp120 interacts with both receptors. Like MAdCAM-1 and VCAM-1, two recognized ligands of ⍺4ß7, the binding interface on CD4 includes 2 sites (1° and accessory), distributed across its two N-terminal IgSF domains (D1 and D2). The 1° site includes a sequence in the G ß-strand of CD4 D2, KIDIV, that binds directly to ⍺4ß7. This pentapeptide sequence occurs infrequently in eukaryotic proteins. However, a closely related and conserved sequence, KLDIV, appears in the V2 domain of gp120. KLDIV mediates gp120-⍺4ß7 binding. The accessory ⍺4ß7 binding site on CD4 includes Phe43. The Phe43 aromatic ring protrudes outward from one edge of a loop connecting the C'C" strands of CD4 D1. Phe43 is a principal contact for HIV gp120. It interacts with conserved residues in the recessed CD4 binding pocket. Substitution of Phe43 abrogates CD4 binding to both gp120 and ⍺4ß7. As such, the interactions of gp120 with both CD4 and ⍺4ß7 reflect elements of their interactions with each other. These findings indicate that gp120 specificities for CD4 and ⍺4ß7 are interrelated and suggest that selective pressures which produced a CD4 tropic virus that replicates in gut tissues are linked to a dynamic interaction between these two receptors.

Better efficacy, lower recurrence rate and decreased CD8+TRM with guselkumab treatment for generalized pustular psoriasis: A prospective cohort study from China.

Generalized pustular psoriasis (GPP) is a severe and uncommon form of psoriasis, for which treatment options are limited. There is an urgent need to expand the treatment options for GPP. Currently, adalimumab, secukinumab, and guselkumab are considered effective for GPP, but there is a lack of prospective direct comparative studies on their efficacy for GPP. We conducted a prospective, single-center, observational study on 50 GPP patients to compare the efficacy, safety, and recurrence rates of these three biologics. Adalimumab, secukinumab, and guselkumab resulted in varying degrees of improvement in patients with GPP, but guselkumab exhibited superior efficacy and a lower recurrence rate than the other two drugs. This enhanced response may be attributed to the significant reduction in CD8+ tissue-resident memory T cells within GPP lesions caused by guselkumab.

CRISPR/Cas9-mediated efficient white genome editing in the black soldier fly Hermetia illucens.

The CRISPR/Cas9 system is the most straightforward genome-editing technology to date, enabling genetic engineering in many insects, including the black soldier fly, Hermetia illucens. The white gene plays a significant role in the multifarious life activities of insects, especially the pigmentation of the eyes. In this study, the white gene of H. illucens (Hiwhite) was cloned, identified, and bioinformatically analysed for the first time. Using quantitative real-time polymerase chain reaction (qPCR), we found that the white gene was expressed in the whole body of the adult flies, particularly in Malpighian tubules and compound eyes. Furthermore, we utilised CRISPR/Cas9-mediated genome-editing technology to successfully generate heritable Hiwhite mutants using two single guide RNAs. During Hiwhite genome editing, we determined the timing, method, and needle-pulling parameters for embryo microinjection by observing early embryonic developmental features. We used the CasOT program to obtain highly specific guide RNAs (gRNAs) at the genome-wide level. According to the phenotypes of Hiwhite knockout strains, the pigmentation of larval stemmata, imaginal compound eyes, and ocelli differed from those of the wild type. These phenotypes were similar to those observed in other insects harbouring white gene mutations. In conclusion, our results described a detailed white genome editing process in black soldier flies, which lays a solid foundation for intensive research on the pigmentation pathway of the eyes and provides a methodological basis for further genome engineering applications in black soldier flies.

A novel online calculator based on clinical features and hematological parameters to predict total skin clearance in patients with moderate to severe psoriasis.

BACKGROUND: Treatment responses to biologic agents vary between patients with moderate to severe psoriasis; while some patients achieve total skin clearance (TSC), a proportion of patients may only experience partial improvement. OBJECTIVE: This study was designed to identify potential predictors for achieving TSC in psoriasis patients treated with IL-17 inhibitors. It also aimed to develop an easy-to-use calculator incorporating these factors by the nomogram to predict TSC response. METHODS: A total of 381 patients with psoriasis receiving ixekizumab were included in the development cohort and 229 psoriasis patients who initiated secukinumab treatment were included in the validation cohort. The study endpoint was achieving TSC after 12 weeks of IL-17 inhibitors treatment, defined as the 100% improvement in Psoriasis Area and Severity Index (PASI 100). Multivariate Cox regression analyses and LASSO analysis were performed to identify clinical predictors and blood predictors respectively. RESULTS: The following parameters were identified as predictive factors associated with TSC: previous biologic treatment, joint involvement, genital area affected, early response (PASI 60 at week 4), neutrophil counts and uric acid levels. The nomogram model incorporating these factors achieved good discrimination in the development cohort (AUC, 0.721; 95% CI 0.670-0.773) and validation cohort (AUC, 0.715; 95% CI 0.665-0.760). The calibration curves exhibited a satisfactory fit, indicating the accuracy of the model. Furthermore, the decision curve analysis confirmed the clinical utility of the nomogram, highlighting its favorable value for practical application. Web-based online calculator has been developed to enhance the efficiency of clinical applications. CONCLUSIONS: This study developed a practical and clinically applicable nomogram model for the prediction of TSC in patients with moderate to severe psoriasis. The nomogram model demonstrated robust predictive performance and exhibited significant clinical utility. Trial registration A multi-center clinical study of systemic treatment strategies for psoriasis in Chinese population;ChiCTR2000036186; Registered 31 August 2020; https://www.chictr.org.cn/showproj.html?proj=58256 .

Insulin Resistance Impairs Biological Agents Response in Moderate-to-Severe Plaque Psoriasis: Insights from a Prospective Cohort Study in China.

BACKGROUND: Psoriasis and insulin resistance (IR) are closely related, but it remains unclear whether IR affects the treatment of patients with psoriasis. OBJECTIVE: The objective of this study was to investigate whether IR impairs the treatment response to biologic agents in patients with moderate-to-severe plaque psoriasis. METHODS: This project was based on a prospective cohort study design. Data for this study were collected from the Shanghai Psoriasis Effectiveness Evaluation CoHort (SPEECH), which is a prospective cohort exploring treatment strategies for psoriasis in China. IR was assessed using the triglyceride glucose-body mass index (TyG-BMI). Psoriasis severity was assessed using the Psoriasis Area and Severity Index (PASI) and Physician's Global Assessment (PGA). Multiple logistic regression was used to explore the differences between patients with high and low levels of IR. Subgroup and sensitivity analyses were performed to examine the robustness of the study results. RESULTS: A total of 290 patients were included in the analysis. Based on the median TyG-BMI, the patients were divided into two groups: High and Low. The High group exhibited a higher prevalence of diabetes, higher BMI, fasting blood glucose, and triglyceride compared with the Low group. Further analysis of the treatment efficacy revealed that the High group had lower response rates for PASI 75, PASI 90, and PGA 0/1 after 12 weeks of treatment. In the Low group, 81.94% of patients achieved PASI 75, 58.33% achieved PASI 90, and 75.69% achieved PGA 0/1. However, the proportion of responses at each endpoint was significantly lower in the High group. The impairment in response to PGA 0/1 was more significant in the High group, indicated by lower odd ratios. Subsequent subgroup analysis and sensitivity analysis produced consistent results. CONCLUSION: IR is associated with lower effectiveness of biologics in patients with psoriasis. CLINICAL TRIAL REGISTRATION: [www.chictr.org.cn], identifier [ChiCTR2000036186].

Single-cell transcriptome sequencing reveals Wolbachia-mediated modification in early stages of Drosophila spermatogenesis.

Wolbachia are the most widely distributed intracellular bacteria, and their most common effect on host phenotype is cytoplasmic incompatibility (CI). A variety of models have been proposed to decipher the molecular mechanism of CI, among which the host modification (HM) model predicts that Wolbachia effectors play an important role in sperm modification. However, owing to the complexity of spermatogenesis and testicular cell-type heterogeneity, whether Wolbachia have different effects on cells at different stages of spermatogenesis or whether these effects are linked with CI remains unknown. Therefore, we used single-cell RNA sequencing to analyse gene expression profiles in adult male Drosophila testes that were infected or uninfected by Wolbachia. We found that Wolbachia significantly affected the proportion of different types of germ cells and affected multiple metabolic pathways in germ cells. Most importantly, Wolbachia had the greatest impact on germline stem cells, resulting in dysregulated expression of genes related to DNA compaction, and Wolbachia infection also influenced the histone-to-protamine transition in the late stage of sperm development. These results support the HM model and suggest that future studies on Wolbachia-induced CI should focus on cells in the early stages of spermatogenesis.

Quality of Life Benefit and Clinical Predictors of Complete Skin Clearance in Psoriasis: A Multicenter, Prospective, Real-World Study.

BACKGROUND: Newer biologics, such as interleukin (IL)-17 inhibitors, make it possible to achieve complete skin clearance (CSC) in patients with moderate-to-severe psoriasis. However, the clinical meaningfulness and predictive factors of CSC in daily practice have not yet been fully investigated. OBJECTIVE: The study was conducted to, first, assess the impact of CSC on quality of life (QoL) improvements compared with treatment responses without clearance and, second, identify clinical parameters as predictors of CSC response in psoriasis patients treated with ixekizumab. METHODS: Patients attending 26 dermatology centers across China were recruited into this real-world setting between August 2020 and May 2022. Prospective cohort study in which response to ixekizumab was assessed using the Psoriasis Area and Severity Index (PASI) and Dermatology Quality of Life Index (DLQI). The absolute DLQI score and DLQI (0) response at week 12 were compared between groups achieving various levels of skin clearance. A stepwise logistic regression analysis was applied to identify which baseline clinical characteristics were predictive factors for CSC. RESULTS: After 12 weeks of treatment, 226 of 511 (44.2%) patients achieved CSC, defined as 100% improvement in PASI score (PASI-100). A significantly higher proportion of patients with CSC versus almost clear skin (PASI 90-99) achieved DLQI score of 0, corresponding to the experience of no impairment on QoL (54.4% vs. 37.7%, p = 0.001). Females patients were more likely than males to achieve CSC response (odds ratio [OR] = 1.83; 95% confidence interval [CI]: 1.24-2.70), while previous biologic treatment (OR = 0.43; 95% CI: 0.24-0.81) and joint affected (OR = 0.61; 95% CI: 0.42-0.89) were significantly associated with less CSC response. CONCLUSIONS: This study highlights the fact that clinical parameters are important in determining CSC response in psoriasis. In daily practice, achieving CSC represents a clinically meaningful treatment goal, especially from the patient perspective.

Analysis of related factors affecting hemoporfin-mediated photodynamic therapy for port-wine stain: A retrospective study.

BACKGROUND: Hemoporfin-mediated photodynamic therapy (HMME-PDT) is currently considered one of the most promising therapies for port-wine stain (PWS). However, the efficacy of this is very variable and needs further studies. METHODS: A total of 101 patients with PWS in the face, neck, or extremities who received at least 2 HMME-PDT sessions were included in the study, and correlations of efficacy with age, gender, locations, treatment sessions, and PDL treatment history were analyzed. RESULTS: The efficacy of HMME-PDT in patients with different ages, locations, and different numbers of prior PDL treatment showed constantly significant differences after 1/2/last session (p < .05). The number of treatments was associated with efficacy, and patients who received more than two sessions had a better response than those who underwent two sessions only (p < .001). Ordinal logistic regression analysis confirmed the above-mentioned associations. Nevertheless, patients of different sex, subtype, and lesion size showed no significant differences. CONCLUSIONS: Our studies demonstrated that HMME-PDT is effective in the treatment of PWS. The more prior PDL treatments, older age, lips involvement, PWS on limbs were adverse factors for Hemoporfin-PDT, while multiple HMME-PDT sessions can improve effective and response rate. Besides, ambient temperature and lesions temperature should be concerned, local cooling provides some relief from pain but may influence effect.

Commutability evaluation of candidate reference materials and ERM-DA470k/IFCC for immunoglobulin M using two international approaches.

BACKGROUND: This study aimed to assess the commutability of frozen pooled human serum (PHS), high concentration of Immunoglobulin M (IgM) pure diluted materials (HPDM), commercialized pure materials (CPM), and dilutions of ERM-DA470k/IFCC in IgM detection using the CLSI and IFCC approaches, to support standardization or harmonization of IgM measurement. METHODS: Twenty-four serum samples, relevant reference materials (PHS, HPDM, CPM), and different ERM-DA470k/IFCC dilutions were analyzed in triplicate using six routine methods. The commutability of the relevant reference materials was carried out following CLSI EP30-A and IFCC bias analysis. RESULTS: According to the CLSI approach, low, medium, and high concentrations of PHS, HPDM, and CPM were commutable on 10, 13, 15, 13, and 8 of 15 assay combinations, respectively. Using the IFCC approach, low, medium, and high concentrations of PHS, HPDM, and CPM were commutable on 10, 11, 9, 15, and 10 of 15 assay combinations, respectively. The ERM-DA470k/IFCC dilutions with D-PBS and RPMI-1640 Medium were commutable on 13 of 15 assay combinations according to CLSI and were commutable on all 15 assay combinations using IFCC approach. CONCLUSIONS: High concentration of PHS were commutable on all six detection systems using the CLSI approach. Low and medium concentration of PHS showed unsatisfied commutability. HPDM, not CPM have good commutability, has the potential to become reference materials. ERM-DA470k/IFCC diluted with different medium showed different commutability.

Trichome-Specific Analysis and Weighted Gene Co-Expression Correlation Network Analysis (WGCNA) Reveal Potential Regulation Mechanism of Artemisinin Biosynthesis in Artemisia annua.

Trichomes are attractive cells for terpenoid biosynthesis and accumulation in Artemisia annua. However, the molecular process underlying the trichome of A. annua is not yet fully elucidated. In this study, an analysis of multi-tissue transcriptome data was performed to examine trichome-specific expression patterns. A total of 6646 genes were screened and highly expressed in trichomes, including artemisinin biosynthetic genes such as amorpha-4,11-diene synthase (ADS) and cytochrome P450 monooxygenase (CYP71AV1). Mapman and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that trichome-specific genes were mainly enriched in lipid metabolism and terpenoid metabolism. These trichome-specific genes were analyzed by a weighted gene co-expression network analysis (WGCNA), and the blue module linked to terpenoid backbone biosynthesis was determined. Hub genes correlated with the artemisinin biosynthetic genes were selected based on TOM value. ORA, Benzoate carboxyl methyltransferase (BAMT), Lysine histidine transporter-like 8 (AATL1), Ubiquitin-like protease 1 (Ulp1) and TUBBY were revealed as key hub genes induced by methyl jasmonate (MeJA) for regulating artemisinin biosynthesis. In summary, the identified trichome-specific genes, modules, pathways and hub genes provide clues and shed light on the potential regulatory mechanisms of artemisinin biosynthesis in trichomes in A. annua.

A highly accurate delta check method using deep learning for detection of sample mix-up in the clinical laboratory.

OBJECTIVES: Delta check (DC) is widely used for detecting sample mix-up. Owing to the inadequate error detection and high false-positive rate, the implementation of DC in real-world settings is labor-intensive and rarely capable of absolute detection of sample mix-ups. The aim of the study was to develop a highly accurate DC method based on designed deep learning to detect sample mix-up. METHODS: A total of 22 routine hematology test items were adopted for the study. The hematology test results, collected from two hospital laboratories, were independently divided into training, validation, and test sets. By selecting six mainstream algorithms, the Deep Belief Network (DBN) was able to learn error-free and artificially (intentionally) mixed sample results. The model's analytical performance was evaluated using training and test sets. The model's clinical validity was evaluated by comparing it with three well-recognized statistical methods. RESULTS: When the accuracy of our model in the training set reached 0.931 at the 22nd epoch, the corresponding accuracy in the validation set was equal to 0.922. The loss values for the training and validation sets showed a similar (change) trend over time. The accuracy in the test set was 0.931 and the area under the receiver operating characteristic curve was 0.977. DBN demonstrated better performance than the three comparator statistical methods. The accuracy of DBN and revised weighted delta check (RwCDI) was 0.931 and 0.909, respectively. DBN performed significantly better than RCV and EDC. Of all test items, the absolute difference of DC yielded higher accuracy than the relative difference for all methods. CONCLUSIONS: The findings indicate that input of a group of hematology test items provides more comprehensive information for the accurate detection of sample mix-up by machine learning (ML) when compared with a single test item input method. The DC method based on DBN demonstrated highly effective sample mix-up identification performance in real-world clinical settings.

Association between statin use and second cancer risk in breast cancer patients: a nationwide population-based cohort study.

PURPOSE: Many studies have revealed that statin therapy reduced mortality in cancer patients, especially in breast cancer, but the effect for second cancer was unclear. We, therefore, performed a comparable cohort study to determine the risk of second cancer in breast cancer patients with statin therapy. METHODS: Using claims data from Taiwan's National Health Insurance Program, this study enrolled newly diagnosed breast cancer patients from 2000 to 2007 with and without statin therapy as the statin (n = 1222) and nonstatin (n = 4888) cohorts, respectively. The nonstatin cohort was propensity score matched by cohort entry year, age, and randomly selected comorbidities. These two cohorts were followed up until the diagnosis of second cancer, death, or the end of 2011. Cox proportional hazard models were used to estimate the hazard ratios. RESULTS: The statin cohort had a lower incidence rate than the nonstatin cohort for second cancer (7.37 vs. 8.36 per 1000 person-years), although the difference was not significant (adjusted hazard ratio [aHR] 0.90, 95% confidence interval [CI] 0.65-1.26). Compared with the nonstatin cohort, the second cancer risk was significantly higher for patients taking pravastatin (aHR 2.71, 95% CI 1.19-6.19) but lower for those receiving multiple statin treatment (aHR 0.45, 95% CI 0.25-0.81) and combined lipophilic and hydrophilic type of statin (aHR 0.42, 95% CI 0.20-0.89). The risk was lower for patients receiving a cumulative defined daily dose (cDDD) of > 430 (aHR 0.41, 95% CI 0.19-0.86). CONCLUSION: This study showed that there is little association between statin use and second cancer risk in breast cancer patients.

Proteomics and ultrastructural analysis of Hermetia illucens (Diptera: Stratiomyidae) larval peritrophic matrix.

BACKGROUND: The black soldier fly (Hermetia illucens) has significant economic potential. The larvae can be used in financially viable waste management systems, as they are voracious feeders able to efficiently convert low-quality waste into valuable biomass. However, most studies on H. illucens in recent decades have focused on optimizing their breeding and bioconversion conditions, while information on their biology is limited. METHODS: About 200 fifth instar well-fed larvae were sacrificed in this work. The liquid chromatography-tandem mass spectrometry and scanning electron microscopy were employed in this study to perform a proteomic and ultrastructural analysis of the peritrophic matrix (PM) of H. illucens larvae. RESULTS: A total of 565 proteins were identified in the PM samples of H. illucen, of which 177 proteins were predicted to contain signal peptides, bioinformatics analysis and manual curation determined 88 proteins may be associated with the PM, with functions in digestion, immunity, PM modulation, and others. The ultrastructure of the H. illucens larval PM observed by scanning electron microscopy shows a unique diamond-shaped chitin grid texture. CONCLUSIONS: It is the first and most comprehensive proteomics research about the PM of H. illucens larvae to date. All the proteins identified in this work has been discussed in details, except several unnamed or uncharacterized proteins, which should not be ignored and need further study. A comparison of the ultrastructure between H. illucens larval PM and those of other insects as observed by SEM indicates that the PM displays diverse textures on an ultra-micro scale and we suscept a unique diamond-shaped chitin grid texture may help H. illucens larval to hold more food. This work deepens our understanding of the molecular architecture and ultrastructure of the H. illucens larval PM.

Association of Wolbachia with Gene Expression in Drosophila Testes.

Wolbachia is a genus of intracellular symbiotic bacteria that are widely distributed in arthropods and nematodes. These maternally inherited bacteria regulate host reproductive systems in various ways to facilitate their vertical transmission. Since the identification of Wolbachia in many insects, the relationship between Wolbachia and the host has attracted great interest. Numerous studies have indicated that Wolbachia modifies a variety of biological processes in the host. Previous studies in Drosophila melanogaster (D. melanogaster) have demonstrated that Wolbachia can affect spermatid differentiation, chromosome deposition, and sperm activity in the early stages of spermatogenesis, leading to sperm dysfunction. Here, we explored the putative effect of Wolbachia in sperm maturation using transcriptomic approaches to compare gene expression in Wolbachia-infected and Wolbachia-free D. melanogaster adult testes. Our findings show that Wolbachia affects many biological processes in D. melanogaster adult testes, and most of the differentially expressed genes involved in carbohydrate metabolism, lysosomal degradation, proteolysis, lipid metabolism, and immune response were upregulated in the presence of Wolbachia. In contrast, some genes that are putatively associated with cutin and wax biosynthesis and peroxisome pathways were downregulated. We did not find any differentially expressed genes that are predicted to be related to spermatogenesis in the datasets. This work provides additional information for understanding the Wolbachia-host intracellular relationships.

Acute hemiparesis. A rare presentation of spontaneous spinal epidural hematoma mimicking acute stroke.

Acute hemiparesis is an extremely rare presentation of spontaneous spinal epidural hematoma, which may be misdiagnosed as acute ischemic stroke and improperly treated with an intravenous thrombolytic agent. Here, we report a case of a 54-year-old woman who presented with acute neck pain and right-sided weakness. She was initially suspected of having ischemic stroke and therefore treated with an intravenous thrombolytic agent. However, she developed progressive tetraparesis, and subsequent magnetic resonance images confirmed cervical spontaneous spinal epidural hematoma.

Heterologous expression and biochemical characterization of a thermostable xylulose kinase from Bacillus coagulans IPE22.

Xylulose kinase is an important enzyme involved in xylose metabolism, which is considered as essential biocatalyst for sustainable lignocellulosic-derived pentose utilization. Bacillus coagulans IPE22 is an ideal bacterium for refinery due to its strong ability to ferment xylose at high temperature. However, the B. coagulans xylose utilization mechanism remains unclear and the related promising enzymes need to be developed. In the present study, the gene coding for xylulose kinase from B. coagulans IPE22 (Bc-XK) was expressed in Escherichia coli BL21 (DE3). Bc-XK has a 1536 bp open reading frame, encoding a protein of 511 amino acids (56.15 kDa). Multiple sequence alignments were performed and a phylogenetic tree was built to evaluate differences among Bc-XK and other bacteria homologs. Bc-XK showed a broad adaptability to high temperature and the enzyme displayed its best performance at pH 8.0 and 60 °C. Bc-XK was activated by Mg2+ , Mn2+ , and Co2+ . Meanwhile, the enzyme could keep activity at 60 °C for at least 180 min. KM values of Bc-XK for xylulose and ATP were 1.29 mM and 0.76 mM, respectively. The high temperature stability of Bc-XK implied that it was an attractive candidate for industrial application.

Response of ammonia-oxidizing archaea to heavy metal contamination in freshwater sediment.

It has been well-documented that the distribution of ammonia-oxidizing bacteria (AOB) and archaea (AOA) in soils can be affected by heavy metal contamination, whereas information about the impact of heavy metal on these ammonia-oxidizing microorganisms in freshwater sediment is still lacking. The present study explored the change of sediment ammonia-oxidizing microorganisms in a freshwater reservoir after being accidentally contaminated by industrial discharge containing high levels of metals. Bacterial amoA gene was found to be below the quantitative PCR detection and was not successfully amplified by conventional PCR. The number of archaeal amoA gene in reservoir sediments were 9.62 × 102-1.35 × 107 copies per gram dry sediment. AOA abundance continuously decreased, and AOA richness, diversity and community structure also considerably varied with time. Therefore, heavy metal pollution could have a profound impact on freshwater sediment AOA community. This work could expand our knowledge of the effect of heavy metal contamination on nitrification in natural ecosystems.