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1.
Haematologica ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39021214

RESUMO

In multiple myeloma (MM), advancements in treatments and toxicity management have enhanced survival rates. This, coupled with shifting age demographics in MM, necessitates an updated understanding of infection risks in MM patients compared to the general population. Using Swedish population-based registries, we investigated the incidence of infections in 8,672 Swedish symptomatic MM patients diagnosed 2008-2021 and 34,561 matched controls. Overall, MM patients had a 5-fold risk (hazard ratio (HR) = 5.30; 95%, Confidence Interval = CI 5.14-5.47) of developing any clinically significant infection compared to matched controls. Bacterial infections represented a 5-fold (HR 4.88; CI 4.70-5.07) increased risk, viral and fungal infections 7-fold compared to controls. The 1st year after MM diagnosis the risk of infections compared to controls was 7 -fold (HR 6.95; CI 6.61-7.30) and remained elevated up to 5 years after the myeloma diagnosis. The risk of infection compared to controls remained 5-fold in MM patients with follow-up till 2022. Preceding MM diagnosis, the risk compared to matched controls was significantly increased up to four years before MM diagnosis (HR1.16; CI 1.05-1.28). Among MM patients, 8% had died within 2 months of diagnosis and infection contributed to 32% of all deaths. After 1 year, 20% MM patients had died, and infection-related mortality was 27%. Our data constitute the largest population-based study to date on the risk of infections compared to the normal population in the era of modern MM therapies and confirms that infections still represent a major threat to patients and underscores importance of preventive strategies.

2.
Cell Rep ; 43(4): 114012, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38573856

RESUMO

Plasmodium falciparum is a human-adapted apicomplexan parasite that causes the most dangerous form of malaria. P. falciparum cysteine-rich protective antigen (PfCyRPA) is an invasion complex protein essential for erythrocyte invasion. The precise role of PfCyRPA in this process has not been resolved. Here, we show that PfCyRPA is a lectin targeting glycans terminating with α2-6-linked N-acetylneuraminic acid (Neu5Ac). PfCyRPA has a >50-fold binding preference for human, α2-6-linked Neu5Ac over non-human, α2-6-linked N-glycolylneuraminic acid. PfCyRPA lectin sites were predicted by molecular modeling and validated by mutagenesis studies. Transgenic parasite lines expressing endogenous PfCyRPA with single amino acid exchange mutants indicated that the lectin activity of PfCyRPA has an important role in parasite invasion. Blocking PfCyRPA lectin activity with small molecules or with lectin-site-specific monoclonal antibodies can inhibit blood-stage parasite multiplication. Therefore, targeting PfCyRPA lectin activity with drugs, immunotherapy, or a vaccine-primed immune response is a promising strategy to prevent and treat malaria.


Assuntos
Eritrócitos , Plasmodium falciparum , Polissacarídeos , Proteínas de Protozoários , Humanos , Antígenos de Protozoários/metabolismo , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/genética , Eritrócitos/parasitologia , Eritrócitos/metabolismo , Lectinas/metabolismo , Lectinas/genética , Malária Falciparum/parasitologia , Plasmodium falciparum/metabolismo , Polissacarídeos/metabolismo , Ligação Proteica , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/genética
3.
Cureus ; 15(6): e39989, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37416044

RESUMO

Arterioureteral fistula (AUF) is a direct communication between the ureter and an artery and is a rare cause of catastrophic, life-threatening haematuria. Fistulation may occur between the ureter and the abdominal aorta, common iliac, external and internal iliac, and inferior mesenteric arteries, and is typically observed in patients with a prior history of pelvic radiotherapy, oncological pelvic surgeries, aortoiliac vascular procedures, and pelvic exenteration. There is also an increased frequency of cases amongst patients who have undergone urological diversion surgeries and in those with chronic indwelling ureteric stents requiring repeated exchange. As AUF is so rarely encountered in clinical practice, the urologist may fail to appreciate its presence until late in the patient's presentation; such diagnostic delay is associated with high mortality and thus rapid clinical suspicion and investigative action are necessary. There are sporadic cases of this rare entity mentioned in literature. In this report, we present two cases as well as a review of the literature. A 73-year-old female presented with repeated episodic haematuria for a week in whom the cause of symptoms remained persistently elusive despite repeated imaging and operative approaches. An eventual diagnosis of a secondary right internal iliac-ureteral fistula was ascertained on a subsequent digital subtraction angiography of the renal tract. The fistula was embolised using an endovascular approach. The patient remained stable post emobilisation and was successfully discharged shortly after the procedure. In the second case, a 51-year-old female, presented with hematuria from her ileal conduit for a few days. Initially, the cause of symptoms was thought to be due to ureteric stents. During a change in her stents, brisk bleeding led to further investigation including an iliac angiogram confirming bleeding from the left common iliac artery. She had a covered common iliac artery stent, which successfully controlled her bleeding This report emphasizes the diagnostic difficulty of AUF, outlines the management principles of this rare disease, and aims to increase awareness of this rare yet potentially lethal phenomenon among practitioners of urology and interventional radiology.

4.
J Arthroplasty ; 38(6S): S275-S280, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36739924

RESUMO

BACKGROUND: Revisions of total knee arthroplasties (TKAs) may require revision of one or both tibial and femoral components. Our purpose was to examine the clinical and functional outcomes in 1- versus 2-component TKA revisions. METHODS: We identified 92 1-component (tibial or femoral) revisions at a single center. Our inclusion criteria were isolated revision of the tibial or femoral components with a minimum 2-year follow-up. The included cases were matched 1:2 with a control group of 2-component revisions (tibial and femoral) by age, body mass index, American Society of Anesthesiologists score, and indication for revision. We collected demographics, complications, operative times, any subsequent rerevisions, and functional outcome scores. RESULTS: The median follow-up time for the 1- and 2-component revision groups were 10 years (range, 3 to 17) and 8 years (range, 2 to 18), respectively. The most common complication after rerevision in both groups was stiffness at 9 of 92 (9.8%) and 9 of 170 (5.3%) in the 1- and 2-component groups, respectively (P = .20). The overall complication prevalence in the 1- and 2- component revision groups was similar 20 of 92 (22%) and 35 of 170 (21%), respectively (P = .87). Subsequent rerevisions for any indication were encountered in 12 of 92 (13.0%) of the 1-component and 18 of 170 (11%) in the 2-component groups (P = .69). There was no statistical difference in survivorship or functional outcomes scores between the groups. CONCLUSION: Our results showed that isolated revision of a single TKA component is an acceptable option, with comparable functional outcomes, complications, and survivorships when compared with both-component revision. As such, a 1-component revision should be considered where appropriate.


Assuntos
Artroplastia do Joelho , Humanos , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/métodos , Articulação do Joelho/cirurgia , Prótese do Joelho/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Desenho de Prótese , Falha de Prótese , Reoperação/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento
5.
Transl Oncol ; 31: 101643, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36805917

RESUMO

One of the forms of aberrant glycosylation in human tumors is the expression of N-glycolylneuraminic acid (Neu5Gc). The only known enzyme to biosynthesize Neu5Gc in mammals, cytidine-5'-monophosphate-N-acetylneuraminic acid (CMAH), appears to be genetically inactivated in humans. Regardless, low levels of Neu5Gc have been detected in healthy humans. Therefore, it is proposed that the presence of Neu5Gc in humans is from dietary acquisition, such as red meat. Notably, detection of elevated Neu5Gc levels has been repeatedly found in cancer tissues, cells and serum samples, thereby Neu5Gc-containing antigens may be exploited as a class of cancer biomarkers. Here we review the findings to date on using Neu5Gc-containing tumor glycoconjugates as a class of cancer biomarkers for cancer detection, surveillance, prognosis and therapeutic targets. We review the evidence that supports an emerging hypothesis of de novo Neu5Gc biosynthesis in human cancer cells as a source of Neu5Gc in human tumors, generated under certain metabolic conditions.

6.
Biochem Biophys Res Commun ; 642: 162-166, 2023 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-36580827

RESUMO

Cutaneous melanoma is one of the most aggressive and deadly types of skin cancer and rates of disease are continuing to increase worldwide. Currently, no serum biomarkers exist for the early detection of cutaneous melanoma. Normal human cells cannot make the sialic acid sugar, Neu5Gc, yet human tumor cells express Neu5Gc and Neu5Gc-containing glycoconjugates have been proposed as tumor biomarkers. We engineered a Neu5Gc-specific lectin based on the pentameric B-subunit of the Shiga toxigenic Escherichia coli subtilase cytotoxin, termed SubB2M. We have detected elevated Neu5Gc-containing biomarkers in the sera of ovarian and breast cancer patients in a highly sensitive surface plasmon resonance (SPR)-based assay using our SubB2M lectin. Here, we used the SubB2M-SPR assay to investigate Neu5Gc-containing glycoconjugates in the serum of cutaneous melanoma patients. We found elevated total serum Neu5Gc levels in primary (n = 24) and metastatic (n = 38) patients compared to cancer-free controls (n = 34). Serum Neu5Gc levels detected with SubB2M can distinguish cutaneous melanoma patients from cancer-free controls with high sensitivity and specificity as determined by ROC curve analysis. These data indicate that serum Neu5Gc-containing glycoconjugates are a novel class of biomarkers for cutaneous melanoma, particularly for primary melanoma, and have the potential to contribute to the early diagnosis of this disease.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Melanoma/diagnóstico , Neoplasias Cutâneas/diagnóstico , Ácidos Neuramínicos , Lectinas , Biomarcadores Tumorais , Glicoconjugados , Melanoma Maligno Cutâneo
7.
BMC Cancer ; 22(1): 334, 2022 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-35346112

RESUMO

BACKGROUND: Normal human tissues do not express glycans terminating with the sialic acid N-glycolylneuraminic acid (Neu5Gc), yet Neu5Gc-containing glycans have been consistently found in human tumor tissues, cells and secretions and have been proposed as a cancer biomarker. We engineered a Neu5Gc-specific lectin called SubB2M, and previously reported elevated Neu5Gc biomarkers in serum from ovarian cancer patients using a Surface Plasmon Resonance (SPR)-based assay. Here we report an optimized SubB2M SPR-based assay and use this new assay to analyse sera from breast cancer patients for Neu5Gc levels. METHODS: To enhance specificity of our SPR-based assay, we included a non-sialic acid binding version of SubB, SubBA12, to control for any non-specific binding to SubB2M, which improved discrimination of cancer-free controls from early-stage ovarian cancer. We analysed 96 serum samples from breast cancer patients at all stages of disease compared to 22 cancer-free controls using our optimized SubB2M-A12-SPR assay. We also analysed a collection of serum samples collected at 6 monthly intervals from breast cancer patients at high risk for disease recurrence or spread. RESULTS: Analysis of sera from breast cancer cases revealed significantly elevated levels of Neu5Gc biomarkers at all stages of breast cancer. We show that Neu5Gc serum biomarker levels can discriminate breast cancer patients from cancer-free individuals with 98.96% sensitivity and 100% specificity. Analysis of serum collected prospectively, post-diagnosis, from breast cancer patients at high risk for disease recurrence showed a trend for a decrease in Neu5Gc levels immediately following treatment for those in remission. CONCLUSIONS: Neu5Gc serum biomarkers are a promising new tool for early detection and disease monitoring for breast cancer that may complement current imaging- and biopsy-based approaches.


Assuntos
Neoplasias da Mama , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Recidiva Local de Neoplasia , Ácidos Neuramínicos/metabolismo
8.
mBio ; 13(1): e0217721, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35012346

RESUMO

Transmission of HIV across the mucosal surface of the female reproductive tract to engage subepithelial CD4-positive T cells is not fully understood. Cervical epithelial cells express complement receptor 3 (CR3) (integrin αMß2 or CD11b/CD18). In women, the bacterium Neisseria gonorrhoeae uses CR3 to invade the cervical epithelia to cause cervicitis. We hypothesized that HIV may also use CR3 to transcytose across the cervical epithelia. Here, we show that HIV-1 strains bound with high affinity to recombinant CR3 in biophysical assays. HIV-1 bound CR3 via the I-domain region of the CR3 alpha subunit, CD11b, and binding was dependent on HIV-1 N-linked glycans. Mannosylated glycans on the HIV surface were a high-affinity ligand for the I-domain. Man5 pentasaccharide, representative of HIV N-glycans, could compete with HIV-1 for CR3 binding. Using cellular assays, we show that HIV bound to CHO cells by a CR3-dependent mechanism. Antibodies to the CR3 I-domain or to the HIV-1 envelope glycoprotein blocked the binding of HIV-1 to primary human cervical epithelial (Pex) cells, indicating that CR3 was necessary and sufficient for HIV-1 adherence to Pex cells. Using Pex cells in a Transwell model system, we show that, following transcytosis across an intact Pex cell monolayer, HIV-1 is able to infect TZM-bl reporter cells. Targeting the HIV-CR3 interaction using antibodies, mannose-binding lectins, or CR3-binding small-molecule drugs blocked HIV transcytosis. These studies indicate that CR3/Pex may constitute an efficient pathway for HIV-1 transmission in women and also demonstrate strategies that may prevent transmission via this pathway. IMPORTANCE In women, the lower female reproductive tract is the primary site for HIV infection. How HIV traverses the epithelium to infect CD4 T cells in the submucosa is ill-defined. Cervical epithelial cells have a protein called CR3 on their surface. We show that HIV-1 binds to CR3 with high affinity and that this interaction is necessary and sufficient for HIV adherence to, and transcytosis across, polarized, human primary cervical epithelial cells. This suggests a unique role for CR3 on epithelial cells in dually facilitating HIV-1 attachment and entry. The HIV-CR3 interaction may constitute an efficient pathway for HIV delivery to subepithelial lymphocytes following virus transmission across an intact cervical epithelial barrier. Strategies with potential to prevent transmission via this pathway are presented.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Cricetinae , Animais , Humanos , Feminino , Antígeno de Macrófago 1/metabolismo , HIV-1/metabolismo , Cricetulus , Células Epiteliais/microbiologia , Células CHO , Transcitose , Polissacarídeos/metabolismo
9.
Mol Cell ; 82(4): 803-815.e5, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35077705

RESUMO

The hormone-stimulated glucocorticoid receptor (GR) modulates transcription by interacting with thousands of enhancers and GR binding sites (GBSs) throughout the genome. Here, we examined the effects of GR binding on enhancer dynamics and investigated the contributions of individual GBSs to the hormone response. Hormone treatment resulted in genome-wide reorganization of the enhancer landscape in breast cancer cells. Upstream of the DDIT4 oncogene, GR bound to four sites constituting a hormone-dependent super enhancer. Three GBSs were required as hormone-dependent enhancers that differentially promoted histone acetylation, transcription frequency, and burst size. Conversely, the fourth site suppressed transcription and hormone treatment alleviated this suppression. GR binding within the super enhancer promoted a loop-switching mechanism that allowed interaction of the DDIT4 TSS with the active GBSs. The unique functions of each GR binding site contribute to hormone-induced transcriptional heterogeneity and demonstrate the potential for targeted modulation of oncogene expression.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Dexametasona/farmacologia , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Receptores de Glucocorticoides/agonistas , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética
10.
J Hepatol ; 76(2): 275-282, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34656649

RESUMO

BACKGROUND & AIMS: Only a minority of excess alcohol drinkers develop cirrhosis. We developed and evaluated risk stratification scores to identify those at highest risk. METHODS: Three cohorts (GenomALC-1: n = 1,690, GenomALC-2: n = 3,037, UK Biobank: relevant n = 6,898) with a history of heavy alcohol consumption (≥80 g/day (men), ≥50 g/day (women), for ≥10 years) were included. Cases were participants with alcohol-related cirrhosis. Controls had a history of similar alcohol consumption but no evidence of liver disease. Risk scores were computed from up to 8 genetic loci identified previously as associated with alcohol-related cirrhosis and 3 clinical risk factors. Score performance for the stratification of alcohol-related cirrhosis risk was assessed and compared across the alcohol-related liver disease spectrum, including hepatocellular carcinoma (HCC). RESULTS: A combination of 3 single nucleotide polymorphisms (SNPs) (PNPLA3:rs738409, SUGP1-TM6SF2:rs10401969, HSD17B13:rs6834314) and diabetes status best discriminated cirrhosis risk. The odds ratios (ORs) and (95% CIs) between the lowest (Q1) and highest (Q5) score quintiles of the 3-SNP score, based on independent allelic effect size estimates, were 5.99 (4.18-8.60) (GenomALC-1), 2.81 (2.03-3.89) (GenomALC-2), and 3.10 (2.32-4.14) (UK Biobank). Patients with diabetes and high risk scores had ORs of 14.7 (7.69-28.1) (GenomALC-1) and 17.1 (11.3-25.7) (UK Biobank) compared to those without diabetes and with low risk scores. Patients with cirrhosis and HCC had significantly higher mean risk scores than patients with cirrhosis alone (0.76 ± 0.06 vs. 0.61 ± 0.02, p = 0.007). Score performance was not significantly enhanced by information on additional genetic risk variants, body mass index or coffee consumption. CONCLUSIONS: A risk score based on 3 genetic risk variants and diabetes status enables the stratification of heavy drinkers based on their risk of cirrhosis, allowing for the provision of earlier preventative interventions. LAY SUMMARY: Excessive chronic drinking leads to cirrhosis in some people, but so far there is no way to identify those at high risk of developing this debilitating disease. We developed a genetic risk score that can identify patients at high risk. The risk of cirrhosis is increased >10-fold with just two risk factors - diabetes and a high genetic risk score. Risk assessment using this test could enable the early and personalised management of this disease in high-risk patients.


Assuntos
Predisposição Genética para Doença/classificação , Cirrose Hepática Alcoólica/diagnóstico , Medição de Risco/métodos , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/psicologia , Estudos de Casos e Controles , Estudos de Coortes , Diabetes Mellitus/epidemiologia , Diabetes Mellitus/fisiopatologia , Feminino , Estudo de Associação Genômica Ampla/métodos , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Humanos , Cirrose Hepática Alcoólica/etiologia , Cirrose Hepática Alcoólica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , Medição de Risco/estatística & dados numéricos
11.
mBio ; 12(4): e0181921, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34340539

RESUMO

The Helicobacter pylori chemoreceptor TlpA plays a role in dampening host inflammation during chronic stomach colonization. TlpA has a periplasmic dCache_1 domain, a structure that is capable of sensing many ligands; however, the only characterized TlpA signals are arginine, bicarbonate, and acid. To increase our understanding of TlpA's sensing profile, we screened for diverse TlpA ligands using ligand binding arrays. TlpA bound seven ligands with affinities in the low- to middle-micromolar ranges. Three of these ligands, arginine, fumarate, and cysteine, were TlpA-dependent chemoattractants, while the others elicited no response. Molecular docking experiments, site-directed point mutants, and competition surface plasmon resonance binding assays suggested that TlpA binds ligands via both the membrane-distal and -proximal dCache_1 binding pockets. Surprisingly, one of the nonactive ligands, glucosamine, acted as a chemotaxis antagonist, preventing the chemotaxis response to chemoattractant ligands, and acted to block the binding of ligands irrespective of whether they bound the membrane-distal or -proximal dCache_1 subdomains. In total, these results suggest that TlpA senses multiple attractant ligands as well as antagonist ones, an emerging theme in chemotaxis systems. IMPORTANCE Numerous chemotactic bacterial pathogens depend on the ability to sense a diverse array of signals through chemoreceptors to achieve successful colonization and virulence within their host. The signals sensed by chemoreceptors, however, are not always fully understood. This is the case for TlpA, a dCache_1 chemoreceptor of H. pylori that enables the bacterium to induce less inflammation during chronic infections. H. pylori causes a significant global disease burden, which is driven by the development of gastric inflammation. Accordingly, it is essential to understand the processes by which H. pylori modulates host inflammation. This work uncovers the signals that TlpA can sense and highlights the underappreciated ability to regulate chemotactic responses by antagonistic chemoreceptor ligands, which is an emerging theme among other chemotactic systems.


Assuntos
Proteínas de Bactérias/metabolismo , Células Quimiorreceptoras/metabolismo , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Proteínas de Bactérias/genética , Quimiotaxia , Glucosamina/metabolismo , Ligantes , Simulação de Acoplamento Molecular , Mutação Puntual
12.
mBio ; 12(2)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33758087

RESUMO

The lipooligosaccharide (LOS) of Neisseria gonorrhoeae plays key roles in pathogenesis and is composed of multiple possible glycoforms. These glycoforms are generated by the process of phase variation and by differences in the glycosyltransferase gene content of particular strains. LOS glycoforms of N. gonorrhoeae can be terminated with an N-acetylneuraminic acid (Neu5Ac), which imparts resistance to the bactericidal activity of serum. However, N. gonorrhoeae cannot synthesize the CMP-Neu5Ac required for LOS biosynthesis and must acquire it from the host. In contrast, Neisseria meningitidis can synthesize endogenous CMP-Neu5Ac, the donor molecule for Neu5Ac, which is a component of some meningococcal capsule structures. Both species have an almost identical LOS sialyltransferase, Lst, that transfers Neu5Ac from CMP-Neu5Ac to the terminus of LOS. Lst is homologous to the LsgB sialyltransferase of nontypeable Haemophilus influenzae (NTHi). Studies in NTHi have demonstrated that LsgB can transfer keto-deoxyoctanoate (KDO) from CMP-KDO to the terminus of LOS in place of Neu5Ac. Here, we show that Lst can also transfer KDO to LOS in place of Neu5Ac in both N. gonorrhoeae and N. meningitidis Consistent with access to the pool of CMP-KDO in the cytoplasm, we present data indicating that Lst is localized in the cytoplasm. Lst has previously been reported to be localized on the outer membrane. We also demonstrate that KDO is expressed as a terminal LOS structure in vivo in samples from infected women and further show that the anti-KDO monoclonal antibody 6E4 can mediate opsonophagocytic killing of N. gonorrhoeae Taken together, these studies indicate that KDO expressed on gonococcal LOS represents a new antigen for the development of vaccines against gonorrhea.IMPORTANCE The emergence of multidrug-resistant N. gonorrhoeae strains that are resistant to available antimicrobials is a current health emergency, and no vaccine is available to prevent gonococcal infection. Lipooligosaccharide (LOS) is one of the major virulence factors of N. gonorrhoeae The sialic acid N-acetylneuraminic acid (Neu5Ac) is present as the terminal glycan on LOS in N. gonorrhoeae In this study, we made an unexpected discovery that KDO can be incorporated as the terminal glycan on LOS of N. gonorrhoeae by the alpha-2,3-sialyltransferase Lst. We showed that N. gonorrhoeae express KDO on LOS in vivo and that the KDO-specific monoclonal antibody 6E4 can direct opsonophagocytic killing of N. gonorrhoeae These data support further development of KDO-LOS structures as vaccine antigens for the prevention of infection by N. gonorrhoeae.


Assuntos
Gonorreia/prevenção & controle , Lipopolissacarídeos/metabolismo , Neisseria gonorrhoeae/enzimologia , Neisseria gonorrhoeae/genética , Sialiltransferases/genética , Sialiltransferases/metabolismo , Antígenos de Bactérias/análise , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Vacinas Bacterianas , Colo do Útero/microbiologia , Células Epiteliais/microbiologia , Feminino , Humanos , Lipopolissacarídeos/genética , Lipopolissacarídeos/imunologia , Ácido N-Acetilneuramínico/metabolismo , Neisseria gonorrhoeae/patogenicidade , Neutrófilos/imunologia , Neutrófilos/microbiologia , Fagocitose/imunologia , beta-Galactosídeo alfa-2,3-Sialiltransferase
13.
PLoS Negl Trop Dis ; 15(2): e0009136, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33630844

RESUMO

Mycobacterium ulcerans is the causative agent of the chronic, necrotizing skin disease Buruli ulcer. Modes of transmission and molecular mechanisms involved in the establishment of M. ulcerans infections are poorly understood. Interactions with host glycans are often crucial in bacterial pathogenesis and the 22 kDa M. ulcerans protein MUL_3720 has a putative role in host cell attachment. It has a predicted N-terminal lectin domain and a C-terminal peptidoglycan-binding domain and is highly expressed on the surface of the bacilli. Here we report the glycan-binding repertoire of whole, fixed M. ulcerans bacteria and of purified, recombinant MUL_3720. On an array comprising 368 diverse biologically relevant glycan structures, M. ulcerans cells showed binding to 64 glycan structures, representing several distinct classes of glycans, including sulfated structures. MUL_3720 bound only to glycans containing sulfated galactose and GalNAc, such as glycans known to be associated with keratins isolated from human skin. Surface plasmon resonance studies demonstrated that both whole, fixed M. ulcerans cells and MUL_3720 show high affinity interactions with both glycans and human skin keratin extracts. This MUL_3720-mediated interaction with glycans associated with human skin keratin may contribute to the pathobiology of Buruli ulcer.


Assuntos
Queratinas/metabolismo , Proteínas de Membrana/metabolismo , Mycobacterium ulcerans , Polissacarídeos/metabolismo , Pele/microbiologia , Úlcera de Buruli/microbiologia , Células Epiteliais , Sulfatos
14.
J Clin Med ; 11(1)2021 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-35011863

RESUMO

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty. Staged revision surgery is considered effective in eradicating PJI. We aimed to determine the rate of infection resolution after each stage of staged revision surgery (first stage, repeat first stage, second stage, excision arthroplasty, and reimplantation) and to assess functional outcomes and the mortality rate at ten years in a consecutive series of 30 chronic PJI of total hip arthroplasties. Infection resolution was defined as no clinical nor laboratory evidence of infection at 24 months after the last surgery and after a minimum of 12 months following cessation of antimicrobial treatment. Four patients died within 24 months of their final surgery. Nineteen patients, 73% (worst-case analysis (wca) 63%), were infection free after 1 surgery; 22 patients, 85% (wca 73%), were infection free after 2 surgeries; and 26 patients, 100% (wca 87%), were infection free after three and four surgeries. The median Harris Hip Score was 41 prior to first revision surgery and improved to 74 at twelve months and 76 at ten years after the final surgery. Thirteen patients died at a mean of 64 months from first revision, giving a mortality rate of 43% at ten years, which is approximately 25% higher than that of an age-matched general population. The results show that with repeated aggressive surgical treatment, most PJIs of the hip are curable. Ten years after successful treatment of PJI, functional outcomes and pain are improved and maintained compared to before initial surgery, but this must be balanced against the high 10-year mortality. Level of evidence: cohort studies.

15.
Am J Gastroenterol ; 116(1): 106-115, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32868629

RESUMO

INTRODUCTION: Sustained high alcohol intake is necessary but not sufficient to produce alcohol-related cirrhosis. Identification of risk factors, apart from lifetime alcohol exposure, would assist in discovery of mechanisms and prediction of risk. METHODS: We conducted a multicenter case-control study (GenomALC) comparing 1,293 cases (with alcohol-related cirrhosis, 75.6% male) and 754 controls (with equivalent alcohol exposure but no evidence of liver disease, 73.6% male). Information confirming or excluding cirrhosis, and on alcohol intake and other potential risk factors, was obtained from clinical records and by interview. Case-control differences in risk factors discovered in the GenomALC participants were validated using similar data from 407 cases and 6,573 controls from UK Biobank. RESULTS: The GenomALC case and control groups reported similar lifetime alcohol intake (1,374 vs 1,412 kg). Cases had a higher prevalence of diabetes (20.5% (262/1,288) vs 6.5% (48/734), P = 2.27 × 10-18) and higher premorbid body mass index (26.37 ± 0.16 kg/m2) than controls (24.44 ± 0.18 kg/m2, P = 5.77 × 10-15). Controls were significantly more likely to have been wine drinkers, coffee drinkers, smokers, and cannabis users than cases. Cases reported a higher proportion of parents who died of liver disease than controls (odds ratio 2.25 95% confidence interval 1.55-3.26). Data from UK Biobank confirmed these findings for diabetes, body mass index, proportion of alcohol as wine, and coffee consumption. DISCUSSION: If these relationships are causal, measures such as weight loss, intensive treatment of diabetes or prediabetic states, and coffee consumption should reduce the risk of alcohol-related cirrhosis.


Assuntos
Consumo de Bebidas Alcoólicas/epidemiologia , Café , Diabetes Mellitus/epidemiologia , Cirrose Hepática Alcoólica/epidemiologia , Uso da Maconha/epidemiologia , Obesidade/epidemiologia , Fumar/epidemiologia , Chá , Bebidas Alcoólicas , Austrália/epidemiologia , Estudos de Casos e Controles , Feminino , França/epidemiologia , Alemanha/epidemiologia , Humanos , Modelos Logísticos , Masculino , Anamnese , Pessoa de Meia-Idade , Fatores de Risco , Suíça , Reino Unido/epidemiologia , Estados Unidos/epidemiologia , Vinho
16.
Ann Vasc Surg ; 72: 563-570, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33227478

RESUMO

BACKGROUND: Blunt thoracic aortic injury (BTAI) is associated with a high mortality and large trauma burden. Trauma and resuscitation after injury affect cardiovascular status, which may in turn affect aortic diameter. Measurement of aortic diameter is necessary to guide stent-graft sizing as part of BTAI management. Inaccurate measurement may lead to stent-graft complications. This pilot study aimed to assess the effect of acute major trauma on stent-graft sizing and stent-graft complications, in the context of BTAI and to assess whether any effect could be predicted. METHODS: Patients who were admitted to a UK major trauma center between January 2007 and December 2017, and were diagnosed with BTAI, were identified. The thoracic aortic diameter was measured at six points on initial and surveillance computed tomography imaging. Data on patient demographics, admission heart rate, mean arterial pressure (MAP), and serum lactate were gathered. RESULTS: Thirty-two patients were identified. Twenty met inclusion criteria. Of these, 12 were managed operatively and eight nonoperatively. The mean age was 40, the mean injury severity score was 43, and 85% were male. A mean increase in diameter between initial trauma scan and surveillance scan was noted throughout the thoracic aorta (P < 0.05). Stent-graft oversizing relative to aortic diameter changed significantly from initial trauma imaging to surveillance imaging (P < 0.05). Admission heart rate, MAP, and serum lactate were not predictive of the percentage change in aortic diameter. There were no complications at surveillance imaging (mean 45 days) or during medium term follow-up (mean 532 days). CONCLUSIONS: Aortic diameter is affected by BTAI, acute major trauma, and resuscitation in a significant and variable manner. Measurements of the aorta in a patient with BTAI in the acute trauma setting should be viewed with uncertainty. A lack of complications in the short term is suggestive of a wide tolerance range regarding stent-graft sizing, but long-term results are unknown.


Assuntos
Aorta Torácica/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Stents , Traumatismos Torácicos/cirurgia , Lesões do Sistema Vascular/cirurgia , Ferimentos não Penetrantes/cirurgia , Adulto , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/lesões , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Desenho de Prótese , Estudos Retrospectivos , Traumatismos Torácicos/diagnóstico por imagem , Fatores de Tempo , Centros de Traumatologia , Resultado do Tratamento , Lesões do Sistema Vascular/diagnóstico por imagem , Ferimentos não Penetrantes/diagnóstico por imagem , Adulto Jovem
17.
ACS Infect Dis ; 6(10): 2604-2615, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32926786

RESUMO

Shigella flexneri targets colonic cells in humans to initiate invasive infection processes that lead to dysentery, and direct interactions between their lipopolysaccharide O antigens and blood group A related glycans are involved in the cell adherence interactions. Here, we show that treatment with Tn and sialyl-Tn glycans, monoclonal antibodies and lectins reactive to Tn/sialyl-Tn, and luteolin (a Tn antigen synthesis inhibitor) all significantly inhibited S. flexneri adherence and invasion of cells in vitro. Surface plasmon resonance analysis showed that lipopolysaccharide O antigen had a high affinity interaction with Tn/sialyl-Tn. Immunofluorescence probing of human colon tissue with antibodies detected expression of Tn/sialyl-Tn by MUC2 producing goblet cells (GCs), and S. flexneri incubated with human colon tissue colocalized with GCs. Our findings demonstrate that S. flexneri targets GCs in the human colonic crypts via glycan-glycan interactions, establishing new insight into the infection process in humans.


Assuntos
Antígenos O , Shigella flexneri , Antígenos Glicosídicos Associados a Tumores , Colo , Células Caliciformes , Humanos
18.
mBio ; 11(2)2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32127453

RESUMO

In the absence of a vaccine, multidrug-resistant Neisseria gonorrhoeae has emerged as a major human health threat, and new approaches to treat gonorrhea are urgently needed. N. gonorrhoeae pili are posttranslationally modified by a glycan that terminates in a galactose. The terminal galactose is critical for initial contact with the human cervical mucosa via an interaction with the I-domain of complement receptor 3 (CR3). We have now identified the I-domain galactose-binding epitope and characterized its galactose-specific lectin activity. Using surface plasmon resonance and cellular infection assays, we found that a peptide mimic of this galactose-binding region competitively inhibited the N. gonorrhoeae-CR3 interaction. A compound library was screened for potential drugs that could similarly prohibit the N. gonorrhoeae-CR3 interaction and be repurposed as novel host-targeted therapeutics for multidrug-resistant gonococcal infections in women. Two drugs, methyldopa and carbamazepine, prevented and cured cervical cell infection by multidrug-resistant gonococci by blocking the gonococcal-CR3 I-domain interaction.IMPORTANCE Novel therapies that avert the problem of Neisseria gonorrhoeae with acquired antibiotic resistance are urgently needed. Gonococcal infection of the human cervix is initiated by an interaction between a galactose modification made to its surface appendages, pili, and the I-domain region of (host) complement receptor 3 (CR3). By targeting this crucial gonococcal-I-domain interaction, it may be possible to prevent cervical infection in females. To this end, we identified the I-domain galactose-binding epitope of CR3 and characterized its galactose lectin activity. Moreover, we identified two drugs, carbamazepine and methyldopa, as effective host-targeted therapies for gonorrhea treatment. At doses below those currently used for their respective existing indications, both carbamazepine and methyldopa were more effective than ceftriaxone in curing cervical infection ex vivo This host-targeted approach would not be subject to N. gonorrhoeae drug resistance mechanisms. Thus, our data suggest a long-term solution to the growing problem of multidrug-resistant N. gonorrhoeae infections.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Colo do Útero/citologia , Reposicionamento de Medicamentos , Células Epiteliais/efeitos dos fármacos , Neisseria gonorrhoeae/efeitos dos fármacos , Receptores de Complemento/antagonistas & inibidores , Carbamazepina/farmacologia , Células Cultivadas , Farmacorresistência Bacteriana Múltipla , Células Epiteliais/microbiologia , Feminino , Galactose/metabolismo , Humanos , Metildopa/farmacologia , Receptores de Complemento/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas
19.
Biol Cell ; 112(4): 103-112, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31916263

RESUMO

The effects of cell size, shape and deformability on cellular function have long been a topic of interest. Recently, mechanical phenotyping technologies capable of analysing large numbers of cells in real time have become available. This has important implications for biology and medicine, especially haemato-oncology and immunology, as immune cell mechanical phenotyping, immunologic function, and malignant cell transformation are closely linked and potentially exploitable to develop new diagnostics and therapeutics. In this review, we introduce the technologies used to analyse cellular mechanical properties and review emerging findings following the advent of high throughput deformability cytometry. We largely focus on cells from the myeloid lineage, which are derived from the bone marrow and include macrophages, granulocytes and erythrocytes. We highlight advances in mechanical phenotyping of cells in suspension that are revealing novel signatures of human blood diseases and providing new insights into pathogenesis of these diseases. The contributions of mechanical phenotyping of cells in suspension to our understanding of drug mechanisms, identification of novel therapeutics and monitoring of treatment efficacy particularly in instances of haematologic diseases are reviewed, and we suggest emerging topics of study to explore as high throughput deformability cytometers become prevalent in laboratories across the globe.


Assuntos
Células Mieloides/imunologia , Fenótipo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Fenômenos Biomecânicos , Elasticidade , Citometria de Fluxo , Glucocorticoides/farmacologia , Humanos , Microscopia de Força Atômica , Células Mieloides/efeitos dos fármacos , Neoplasias/tratamento farmacológico
20.
Int J Med Microbiol ; 310(2): 151398, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31987726

RESUMO

Clostridium perfringens is the causative agent of human clostridial myonecrosis; the major toxins involved in this disease are α-toxin and perfringolysin O. The RevSR two-component regulatory system has been shown to be involved in regulating virulence in a mouse myonecrosis model. Previous microarray and RNAseq analysis of a revR mutant implied that factors other than the major toxins may play a role in virulence. The RNAseq data showed that the expression of the gene encoding the EngCP endo α-N-acetylgalactosaminidase (CPE0693) was significantly down-regulated in a revR mutant. Enzymes from this family have been identified in several Gram-positive pathogens and have been postulated to contribute to their virulence. In this study, we constructed an engCP mutant of C. perfringens and showed that it was significantly less virulent than its wild-type parent strain. Virulence was restored by complementation in trans with the wild-type engCP gene. We also demonstrated that purified EngCP was able to hydrolyse α-dystroglycan derived from C2C12 mouse myotubes. However, EngCP had little effect on membrane permeability in mice, suggesting that EngCP may play a role other than the disruption of the structural integrity of myofibres. Glycan array analysis indicated that EngCP could recognise structures containing the monosaccharide N-acetlygalactosamine at 4C, but could recognise structures terminating in galactose, glucose and N-acetylglucosamine under conditions where EngCP was enzymatically active. In conclusion, we have obtained evidence that EngCP is required for virulence in C. perfringens and, although classical exotoxins are important for disease, we have now shown that an O-glycosidase also plays an important role in the disease process.


Assuntos
Clostridium perfringens/enzimologia , Clostridium perfringens/patogenicidade , Gangrena Gasosa/microbiologia , Fatores de Virulência/genética , alfa-N-Acetilgalactosaminidase/genética , Animais , Permeabilidade da Membrana Celular , Clostridium perfringens/genética , Feminino , Regulação Bacteriana da Expressão Gênica , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sequência de RNA , alfa-N-Acetilgalactosaminidase/metabolismo
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