Benign Breast Disease and Breast Cancer Risk in the Percutaneous Biopsy Era.

Importance: Benign breast disease (BBD) comprises approximately 75% of breast biopsy diagnoses. Surgical biopsy specimens diagnosed as nonproliferative (NP), proliferative disease without atypia (PDWA), or atypical hyperplasia (AH) are associated with increasing breast cancer (BC) risk; however, knowledge is limited on risk associated with percutaneously diagnosed BBD. Objectives: To estimate BC risk associated with BBD in the percutaneous biopsy era irrespective of surgical biopsy. Design, Setting, and Participants: In this retrospective cohort study, BBD biopsy specimens collected from January 1, 2002, to December 31, 2013, from patients with BBD at Mayo Clinic in Rochester, Minnesota, were reviewed by 2 pathologists masked to outcomes. Women were followed up from 6 months after biopsy until censoring, BC diagnosis, or December 31, 2021. Exposure: Benign breast disease classification and multiplicity by pathology panel review. Main Outcomes: The main outcome was diagnosis of BC overall and stratified as ductal carcinoma in situ (DCIS) or invasive BC. Risk for presence vs absence of BBD lesions was assessed by Cox proportional hazards regression. Risk in patients with BBD compared with female breast cancer incidence rates from the Iowa Surveillance, Epidemiology, and End Results (SEER) program were estimated. Results: Among 4819 female participants, median age was 51 years (IQR, 43-62 years). Median follow-up was 10.9 years (IQR, 7.7-14.2 years) for control individuals without BC vs 6.6 years (IQR, 3.7-10.1 years) for patients with BC. Risk was higher in the cohort with BBD than in SEER data: BC overall (standard incidence ratio [SIR], 1.95; 95% CI, 1.76-2.17), invasive BC (SIR, 1.56; 95% CI, 1.37-1.78), and DCIS (SIR, 3.10; 95% CI, 2.54-3.77). The SIRs increased with increasing BBD severity (1.42 [95% CI, 1.19-1.71] for NP, 2.19 [95% CI, 1.88-2.54] for PDWA, and 3.91 [95% CI, 2.97-5.14] for AH), comparable to surgical cohorts with BBD. Risk also increased with increasing lesion multiplicity (SIR: 2.40 [95% CI, 2.06-2.79] for ≥3 foci of NP, 3.72 [95% CI, 2.31-5.99] for ≥3 foci of PDWA, and 5.29 [95% CI, 3.37-8.29] for ≥3 foci of AH). Ten-year BC cumulative incidence was 4.3% for NP, 6.6% for PDWA, and 14.6% for AH vs an expected population cumulative incidence of 2.9%. Conclusions and Relevance: In this contemporary cohort study of women diagnosed with BBD in the percutaneous biopsy era, overall risk of BC was increased vs the general population (DCIS and invasive cancer combined), similar to that in historical BBD cohorts. Development and validation of pathologic classifications including both BBD severity and multiplicity may enable improved BC risk stratification.

A drug repurposing screen for whipworms informed by comparative genomics.

Hundreds of millions of people worldwide are infected with the whipworm Trichuris trichiura. Novel treatments are urgently needed as current drugs, such as albendazole, have relatively low efficacy. We have investigated whether drugs approved for other human diseases could be repurposed as novel anti-whipworm drugs. In a previous comparative genomics analysis, we identified 409 drugs approved for human use that we predicted to target parasitic worm proteins. Here we tested these ex vivo by assessing motility of adult worms of Trichuris muris, the murine whipworm, an established model for human whipworm research. We identified 14 compounds with EC50 values of ≤50 µM against T. muris ex vivo, and selected nine for testing in vivo. However, the best worm burden reduction seen in mice was just 19%. The high number of ex vivo hits against T. muris shows that we were successful at predicting parasite proteins that could be targeted by approved drugs. In contrast, the low efficacy of these compounds in mice suggest challenges due to their chemical properties (e.g. lipophilicity, polarity, molecular weight) and pharmacokinetics (e.g. absorption, distribution, metabolism, and excretion) that may (i) promote absorption by the host gastrointestinal tract, thereby reducing availability to the worms embedded in the large intestine, and/or (ii) restrict drug uptake by the worms. This indicates that identifying structural analogues that have reduced absorption by the host, and increased uptake by worms, may be necessary for successful drug development against whipworms.

General Anesthesia for Cesarean Delivery for Thrombocytopenia in Hypertensive Disorders of Pregnancy: Findings From the Obstetric Airway Management Registry.

BACKGROUND: In resource-limited environments, spinal anesthesia (SA) is preferred for cesarean delivery. In women at risk of spinal epidural hematoma, particularly those with hypertensive disorders of pregnancy, thrombocytopenia should be excluded before neuraxial blockade. In the context of emergency surgery for fetal distress, this investigation may be hampered by laboratory services being unavailable or off-site. METHODS: The Obstetric Airway Management Registry (ObAMR) is currently active across all anesthesia training institutions affiliated with the University of Cape Town. This multicenter observational study aimed to estimate the proportion of patients receiving general anesthesia (GA) for either confirmed or suspected thrombocytopenia, which was not excluded due to unavailability of laboratory results. To establish the number of GA uses that may have been avoided if platelet counts were available, we retrospectively searched for subsequent platelet counts in patients for whom thrombocytopenia was suspected. An algorithm was proposed, including a simple decision aid for estimating risk versus benefit of SA versus GA, to be followed in the setting of hypertensive disorders of pregnancy and thrombocytopenia. RESULTS: Thrombocytopenia was the indication for GA in 100 of 591 patients (16.9%) captured in the registry. In total, 48 of 591 (8.1%) had confirmed thrombocytopenia, and 52 of 591 (8.8%) had suspected thrombocytopenia. Of these patients, 91 of 100 had a hypertensive disorder of pregnancy. In the confirmed thrombocytopenia group, the indication for GA was a platelet count <75 × 10 9 /L. In the suspected thrombocytopenia group, 46 of 52 (88.5%) platelet counts could be retrospectively traced. The median (interquartile range) platelet count was 178 × 10 9 /L (93 - 233 × 10 9 /L), and platelets exceeded 75 × 10 9 /L in 41 of 46 patients (89.1%). In the 5 of 46 patients with retrospectively confirmed thrombocytopenia, 2 had hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, 2 had antepartum hemorrhage with preeclampsia, and 1 had isolated thrombocytopenia with preeclampsia. CONCLUSIONS: In 17% of patients, the indication for GA was thrombocytopenia. Of these, 52 of 100, or nearly 9% of the total of 591, received GA because a platelet count was unavailable at the time of surgery. The importance of early laboratory assessment, when available, should be emphasized. Overall, 41 of 591 (6.9%) had a platelet count >75 × 10 9 /L and would not have needed GA if their platelet count had been known. After following the constructed algorithm and applying the decision aid to assess risk and benefit, there may be circumstances in which the clinician justifiably opts for SA when a platelet count is indicated but unavailable.

Group A Streptococcus M1T1 Intracellular Infection of Primary Tonsil Epithelial Cells Dampens Levels of Secreted IL-8 Through the Action of SpyCEP.

Streptococcus pyogenes (Group A Streptococcus; GAS) commonly causes pharyngitis in children and adults, with severe invasive disease and immune sequelae being an infrequent consequence. The ability of GAS to invade the host and establish infection likely involves subversion of host immune defenses. However, the signaling pathways and innate immune responses of epithelial cells to GAS are not well-understood. In this study, we utilized RNAseq to characterize the inflammatory responses of primary human tonsil epithelial (TEpi) cells to infection with the laboratory-adapted M6 strain JRS4 and the M1T1 clinical isolate 5448. Both strains induced the expression of genes encoding a wide range of inflammatory mediators, including IL-8. Pathway analysis revealed differentially expressed genes between mock and JRS4- or 5448-infected TEpi cells were enriched in transcription factor networks that regulate IL-8 expression, such as AP-1, ATF-2, and NFAT. While JRS4 infection resulted in high levels of secreted IL-8, 5448 infection did not, suggesting that 5448 may post-transcriptionally dampen IL-8 production. Infection with 5448ΔcepA, an isogenic mutant lacking the IL-8 protease SpyCEP, resulted in IL-8 secretion levels comparable to JRS4 infection. Complementation of 5448ΔcepA and JRS4 with a plasmid encoding 5448-derived SpyCEP significantly reduced IL-8 secretion by TEpi cells. Our results suggest that intracellular infection with the pathogenic GAS M1T1 clone induces a strong pro-inflammatory response in primary tonsil epithelial cells, but modulates this host response by selectively degrading the neutrophil-recruiting chemokine IL-8 to benefit infection.

Anti-Inflammatory Activity and Structure-Activity Relationships of Brominated Indoles from a Marine Mollusc.

Marine molluscs are rich in biologically active natural products that provide new potential sources of anti-inflammatory agents. Here we used bioassay guided fractionation of extracts from the muricid Dicathais orbita to identify brominated indoles with anti-inflammatory activity, based on the inhibition of nitric oxide (NO) and tumour necrosis factor α (TNFα) in lipopolysaccharide (LPS) stimulated RAW264.7 macrophages and prostaglandin E2 (PGE2) in calcium ionophore-stimulated 3T3 ccl-92 fibroblasts. Muricid brominated indoles were then compared to a range of synthetic indoles to determine structure-activity relationships. Both hypobranchial gland and egg extracts inhibited the production of NO significantly with IC50 of 30.8 and 40 µg/mL, respectively. The hypobranchial gland extract also inhibited the production of TNFα and PGE2 with IC50 of 43.03 µg/mL and 34.24 µg/mL, respectively. The purified mono-brominated indole and isatin compounds showed significant inhibitory activity against NO, TNFα, and PGE2, and were more active than dimer indoles and non-brominated isatin. The position of the bromine atom on the isatin benzene ring significantly affected the activity, with 5Br > 6Br > 7Br. The mode of action for the active hypobranchial gland extract, 6-bromoindole, and 6-bromoisatin was further tested by the assessment of the translocation of nuclear factor kappa B (NFκB) in LPS-stimulated RAW264.7 mouse macrophage. The extract (40 µg/mL) significantly inhibited the translocation of NFκB in the LPS-stimulated RAW264.7 macrophages by 48.2%, whereas 40 µg/mL of 6-bromoindole and 6-bromoistain caused a 60.7% and 63.7% reduction in NFκB, respectively. These results identify simple brominated indoles as useful anti-inflammatory drug leads and support the development of extracts from the Australian muricid D. orbita, as a new potential natural remedy for the treatment of inflammation.

Clinical features of bipolar spectrum with binge eating behaviour.

OBJECTIVE: To determine whether bipolar spectrum disorder with binge eating behavior (BE) is an important clinical sub-phenotype. METHODS: Prevalence rates and correlates of different levels of BE were assessed in 1114 bipolar spectrum patients participating in a genetic biobank. BE and eating disorders (EDs) were assessed with the Eating Disorder Diagnostic Scale (EDDS). Psychiatric illness burden was evaluated with measures of suicidality, psychosis, mood instability, anxiety disorder comorbidity, and substance abuse comorbidity. Medical illness burden was evaluated with body mass index (BMI) and the Cumulative Index Rating Scale (CIRS). RESULTS: Thirty percent of patients had any BE and 27% had BE plus an ED diagnosis. Compared with bipolar spectrum patients without BE, bipolar spectrum patients with BE were younger and more likely to be female; had significantly higher levels of eating psychopathology, suicidality, mood instability, and anxiety disorder comorbidity; had a significantly higher mean BMI and a significantly higher rate of obesity; and had a significantly higher medical illness burden. Bipolar spectrum patients with BE but no ED diagnosis were more similar to bipolar spectrum patients without BE than to those with an ED. Nonetheless, the positive predictive value and specificity of BE predicting an ED was 0.90 and 0.96, respectively. LIMITATIONS: As only two patients had co-occurring anorexia nervosa, these results may not generalize to bipolar spectrum patients with restricting EDs. CONCLUSION: Bipolar spectrum disorder with broadly-defined BE may not be as clinically relevant a sub-phenotype as bipolar spectrum disorder with an ED but may be an adequate proxy for the latter when phenotyping large samples of individuals.

Prevalence and correlates of DSM-5 eating disorders in patients with bipolar disorder.

OBJECTIVE: To determine prevalence rates and clinical correlates of current DSM-5 eating disorders in patients with bipolar disorder (BP). METHODS: Prevalence rates of current DSM-5- and DSM-IV-defined binge eating disorder (BED), bulimia nervosa (BN), and anorexia nervosa (AN) were assessed with the Eating Disorder Diagnostic Scale (EDDS) in 1092 patients with BP. Psychiatric illness burden was evaluated with five proxy measures of BP illness severity. Medical illness burden was evaluated with the Cumulative Index Rating Scale (CIRS). RESULTS: Twenty-seven percent of patients had a current DSM-5 eating disorder: 12% had BED, 15% had BN, and 0.2% had AN. Rates of DSM-5-defined BED and BN were higher than clinical diagnosis rates and rates of DSM-IV-defined BED and BN. Compared with BP patients without an eating disorder, BP patients with a DSM-5 eating disorder were younger and more likely to be women; had an earlier age of onset of BP; had higher EDDS composite scores and higher degrees of suicidality, mood instability, and anxiety disorder comorbidity; and had a higher mean BMI, higher rate of obesity, and higher CIRS total scores. In a logistic regression model controlling for previously identified correlates of an eating disorder, younger age, female gender, and higher BMI remained significantly associated with an eating disorder. LIMITATIONS: The EDDS has not been validated in BP patients. CONCLUSION: DSM-5-defined BED and BN are common in BP patients, possibly more common than DSM-IV-defined BED and BN, and associated with greater psychiatric and general medical illness burden. Further studies assessing DSM-5 eating disorders in people with BP are greatly needed.

National survey and community advisory board development for a bipolar disorder biobank.

OBJECTIVES: The aim of the present study was to engage a national advocacy group and local stakeholders for guidance in developing a bipolar disorder biobank through a web-based survey and a community advisory board. METHODS: The Depression and Bipolar Support Alliance and the Mayo Clinic Bipolar Biobank conducted a national web-based survey inquiring about interest in participating in a biobank (i.e., giving DNA and clinical information). A community advisory board was convened to guide establishment of the biobank and identify key deliverables from the research project and for the community. RESULTS: Among 385 survey respondents, funding source (87%), professional opinion (76%), mental health consumer opinion (79%), and return of research results (91%) were believed to be important for considering study participation. Significantly more patients were willing to participate in a biobank managed by a university or clinic (78.2%) than one managed by government (63.4%) or industry (58.2%; both p < 0.001). The nine-member community advisory board expressed interest in research to help predict the likelihood of bipolar disorder developing in a child of an affected parent and which medications to avoid. The advisory board endorsed the use of a comprehension questionnaire to evaluate participants' understanding of the study (e.g., longevity of DNA specimens, right to remove samples, accessing medical records) as a means to strengthen the informed consent process. CONCLUSIONS: These national survey and community advisory data support the merit of establishing a biobank to enable studies of disease risk, provided that health records and research results are adequately protected. The goals of earlier diagnosis and individualized treatment of bipolar disorder were endorsed.

Development of a bipolar disorder biobank: differential phenotyping for subsequent biomarker analyses.

BACKGROUND: We aimed to establish a bipolar disorder biobank to serve as a resource for clinical and biomarker studies of disease risk and treatment response. Here, we describe the aims, design, infrastructure, and research uses of the biobank, along with demographics and clinical features of the first participants enrolled. METHODS: Patients were recruited for the Mayo Clinic Bipolar Biobank beginning in July 2009. The Structured Clinical Interview for DSM-IV was used to confirm bipolar diagnosis. The Bipolar Biobank Clinical Questionnaire and Participant Questionnaire were designed to collect detailed demographic and clinical data, including clinical course of illness measures that would delineate differential phenotypes for subsequent analyses. Blood specimens were obtained from participants, and various aliquots were stored for future research. RESULTS: As of September 2014, 1363 participants have been enrolled in the bipolar biobank. Among these first participants, 69.0 % had a diagnosis of bipolar disorder type I. The group was 60.2 % women and predominantly white (90.6 %), with a mean (SD) age of 42.6 (14.9) years. Clinical phenotypes of the group included history of psychosis (42.3 %), suicide attempt (32.5 %), addiction to alcohol (39.1 %), addiction to nicotine (39.8 %), obesity (42.9 %), antidepressant-induced mania (31.7 %), tardive dyskinesia (3.2 %), and history of drug-related serious rash (5.7 %). CONCLUSIONS: Quantifying phenotypic patterns of illness beyond bipolar subtype can provide more detailed clinical disease characteristics for biomarker research, including genomic-risk studies. Future research can harness clinically useful biomarkers using state-of-the-art research technology to help stage disease burden and better individualize treatment selection for patients with bipolar disorder.

Clinical risk factors and serotonin transporter gene variants associated with antidepressant-induced mania.

INTRODUCTION: Identifying clinical and genetic risk factors associated with antidepressant-induced mania (AIM) may improve individualized treatment strategies for bipolar depression. METHOD: From 2009 to 2012, bipolar depressed patients, confirmed by DSM-IV-TR-structured interview, were screened for AIM. An AIM+ case was defined as a manic/hypomanic episode within 60 days of starting or changing dose of antidepressant, while an AIM- control was defined as an adequate (≥ 60 days) exposure to an antidepressant with no associated manic/hypomanic episode. 591 subjects (205 AIM+ and 386 AIM-) exposed to an antidepressant and a subset of 545 subjects (191 AIM+ and 354 AIM-) treated with a selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) were used to evaluate the association of AIM with phenotypic clinical risk factors previously published. 295 white subjects (113 AIM+ cases, 182 AIM-controls) were genotyped for 3 SLC6A4 variants: the 5-HTTLPR, single nucleotide polymorphism (SNP) rs25531, and the intron 2 variable number of tandem repeats (VNTR). Tests of association with AIM were performed for each polymorphism and the haplotype. RESULTS: The only clinical risk factors associated with AIM in the overall and the SSRI + SNRI analysis was bipolar I subtype. The S allele of 5-HTTLPR was not significantly associated with AIM; however, a meta-analysis combining this sample with 5 prior studies provided marginal evidence of association (P = .059). The L-A-10 haplotype was associated with a reduced risk of AIM (P = .012). DISCUSSION: Narrowly defined, AIM appears to be at greatest risk for bipolar I patients. Our haplotype analysis of SLC6A4 suggests that future pharmacogenetic studies should not only focus on the SLC6A4 promotor variation but also investigate the role of other variants in the gene.

Proteolytic processing of the cilium adhesin MHJ_0194 (P123J ) in Mycoplasma hyopneumoniae generates a functionally diverse array of cleavage fragments that bind multiple host molecules.

Mycoplasma hyopneumoniae, the aetiological agent of porcine enzootic pneumonia, regulates the presentation of proteins on its cell surface via endoproteolysis, including those of the cilial adhesin P123 (MHJ_0194). These proteolytic cleavage events create functional adhesins that bind to proteoglycans and glycoproteins on the surface of ciliated and non-ciliated epithelial cells and to the circulatory host molecule plasminogen. Two dominant cleavage events of the P123 preprotein have been previously characterized; however, immunoblotting studies suggest that more complex processing events occur. These extensive processing events are characterized here. The functional significance of the P97 cleavage fragments is also poorly understood. Affinity chromatography using heparin, fibronectin and plasminogen as bait and peptide arrays were used to expand our knowledge of the adhesive capabilities of P123 cleavage fragments and characterize a novel binding motif in the C-terminus of P123. Further, we use immunohistochemistry to examine in vivo, the biological significance of interactions between M. hyopneumoniae and fibronectin and show that M. hyopneumoniae induces fibronectin deposition at the site of infection on the ciliated epithelium. Our data supports the hypothesis that M. hyopneumoniae possesses the molecular machinery to influence key molecular communication pathways in host cells.

Mutual exclusivity of hyaluronan and hyaluronidase in invasive group A Streptococcus.

A recent analysis of group A Streptococcus (GAS) invasive infections in Australia has shown a predominance of M4 GAS, a serotype recently reported to lack the antiphagocytic hyaluronic acid (HA) capsule. Here, we use molecular genetics and bioinformatics techniques to characterize 17 clinical M4 isolates associated with invasive disease in children during this recent epidemiology. All M4 isolates lacked HA capsule, and whole genome sequence analysis of two isolates revealed the complete absence of the hasABC capsule biosynthesis operon. Conversely, M4 isolates possess a functional HA-degrading hyaluronate lyase (HylA) enzyme that is rendered nonfunctional in other GAS through a point mutation. Transformation with a plasmid expressing hasABC restored partial encapsulation in wild-type (WT) M4 GAS, and full encapsulation in an isogenic M4 mutant lacking HylA. However, partial encapsulation reduced binding to human complement regulatory protein C4BP, did not enhance survival in whole human blood, and did not increase virulence of WT M4 GAS in a mouse model of systemic infection. Bioinformatics analysis found no hasABC homologs in closely related species, suggesting that this operon was a recent acquisition. These data showcase a mutually exclusive interaction of HA capsule and active HylA among strains of this leading human pathogen.

Participation changes in sexual functioning after mild stroke.

The purpose of this study was to explore the extent to which people with mild stroke experience changes in participation in sexual activity post stroke. A cross-sectional study was completed with adults 6 to 18 months post mild stroke (N = 13); a brief case study was also done with one of the participants. Participants completed an assessment battery over the telephone that included the modified Quality of Sexual Function scale, the Stroke Impact Scale (SIS), and the Patient Health Questionnaire-9. The sample reported mild problems with sexual dysfunction (mean = 10.77, SD = 4.09). Sexual dysfunction post stroke was highly correlated (r(2) = -0.372 to -0.875) with all of the domains on the SIS. Several participants in this study reported that they would have liked more information about sexual functioning post stroke. These findings suggest that individuals with mild stroke are experiencing decreased participation in sexual activities post stroke and would like more information from the health care community on the potential for sexual changes.

The globally disseminated M1T1 clone of group A Streptococcus evades autophagy for intracellular replication.

Autophagy is reported to be an important innate immune defense against the intracellular bacterial pathogen Group A Streptococcus (GAS). However, the GAS strains examined to date belong to serotypes infrequently associated with human disease. We find that the globally disseminated serotype M1T1 clone of GAS can evade autophagy and replicate efficiently in the cytosol of infected cells. Cytosolic M1T1 GAS (strain 5448), but not M6 GAS (strain JRS4), avoids ubiquitylation and recognition by the host autophagy marker LC3 and ubiquitin-LC3 adaptor proteins NDP52, p62, and NBR1. Expression of SpeB, a streptococcal cysteine protease, is critical for this process, as an isogenic M1T1 ΔspeB mutant is targeted to autophagy and attenuated for intracellular replication. SpeB degrades p62, NDP52, and NBR1 in vitro and within the host cell cytosol. These results uncover a proteolytic mechanism utilized by GAS to escape the host autophagy pathway that may underpin the success of the M1T1 clone.

Clinical phenotype of bipolar disorder with comorbid binge eating disorder.

BACKGROUND: To explore the relationship between binge eating disorder (BED) and obesity in patients with bipolar disorder (BP). METHODS: 717 patients participating in the Mayo Clinic Bipolar Biobank completed structured diagnostic interviews and questionnaires for demographic and illness-related variables. They also had weight and height measured to determine body mass index (BMI). The effects of BED and obesity (BMI≥30 kg/m(2)), as well as their interaction, were assessed on one measure of general medical burden and six proxies of psychiatric illness burden. RESULTS: 9.5% of patients received a clinical diagnosis of BED and 42.8% were obese. BED was associated with a significantly elevated BMI. Both BED and obesity were associated with greater psychiatric and general illness burden, but illness burden profiles differed. After controlling for obesity, BED was associated with suicidality, psychosis, mood instability, anxiety disorder comorbidity, and substance abuse comorbidity. After controlling for BED status, obesity was associated with greater general medical comorbidity, but lower substance abuse comorbidity. There were no significant interaction effects between obesity and BED, or BMI and BED, on any illness burden outcome. LIMITATIONS: There may have been insufficient power to detect interactions between BED and obesity. CONCLUSIONS: Among patients with BP, BED and obesity are highly prevalent and correlated, but associated with different profiles of enhanced illness burden. As the association of BED with greater psychiatric illness burden remained significant even after accounting for the effect of obesity, BP with BED may represent a clinically important sub-phenotype.

Characterization of cleavage events in the multifunctional cilium adhesin Mhp684 (P146) reveals a mechanism by which Mycoplasma hyopneumoniae regulates surface topography.

UNLABELLED: Mycoplasma hyopneumoniae causes enormous economic losses to swine production worldwide by colonizing the ciliated epithelium in the porcine respiratory tract, resulting in widespread damage to the mucociliary escalator, prolonged inflammation, reduced weight gain, and secondary infections. Protein Mhp684 (P146) comprises 1,317 amino acids, and while the N-terminal 400 residues display significant sequence identity to the archetype cilium adhesin P97, the remainder of the molecule is novel and displays unusual motifs. Proteome analysis shows that P146 preprotein is endogenously cleaved into three major fragments identified here as P50(P146), P40(P146), and P85(P146) that reside on the cell surface. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) identified a semitryptic peptide that delineated a major cleavage site in Mhp684. Cleavage occurred at the phenylalanine residue within sequence (672)ATEF↓QQ(677), consistent with a cleavage motif resembling S/T-X-F↓X-D/E recently identified in Mhp683 and other P97/P102 family members. Biotinylated surface proteins recovered by avidin chromatography and separated by two-dimensional gel electrophoresis (2-D GE) showed that more-extensive endoproteolytic cleavage of P146 occurs. Recombinant fragments F1(P146)-F3(P146) that mimic P50(P146), P40(P146), and P85(P146) were constructed and shown to bind porcine epithelial cilia and biotinylated heparin with physiologically relevant affinity. Recombinant versions of F3(P146) generated from M. hyopneumoniae strain J and 232 sequences strongly bind porcine plasminogen, and the removal of their respective C-terminal lysine and arginine residues significantly reduces this interaction. These data reveal that P146 is an extensively processed, multifunctional adhesin of M. hyopneumoniae. Extensive cleavage coupled with variable cleavage efficiency provides a mechanism by which M. hyopneumoniae regulates protein topography. IMPORTANCE: Vaccines used to control Mycoplasma hyopneumoniae infection provide only partial protection. Proteins of the P97/P102 families are highly expressed, functionally redundant molecules that are substrates of endoproteases that generate multifunctional adhesin fragments on the cell surface. We show that P146 displays a chimeric structure consisting of an N terminus, which shares sequence identity with P97, and novel central and C-terminal regions. P146 is endoproteolytically processed at multiple sites, generating at least nine fragments on the surface of M. hyopneumoniae. Dominant cleavage events occurred at S/T-X-F↓X-D/E-like sites generating P50(P146), P40(P146), and P85(P146). Recombinant proteins designed to mimic the major cleavage fragments bind porcine cilia, heparin, and plasminogen. P146 undergoes endoproteolytic processing events at multiple sites and with differential processing efficiency, generating combinatorial diversity on the surface of M. hyopneumoniae.

Mhp182 (P102) binds fibronectin and contributes to the recruitment of plasmin(ogen) to the Mycoplasma hyopneumoniae cell surface.

Mycoplasma hyopneumoniae is a major, economically damaging respiratory pathogen. Although M. hyopneumoniae cells bind plasminogen, the identification of plasminogen-binding surface proteins and the biological ramifications of acquiring plasminogen requires further investigation. mhp182 encodes a highly expressed 102 kDa protein (P102) that undergoes proteolytic processing to generate surface-located N-terminal 60 kDa (P60) and C-terminal 42 kDa (P42) proteins of unknown function. We show that recombinant P102 (rP102) binds plasminogen at physiologically relevant concentrations (K(D) ~ 76 nM) increasing the susceptibility of plasmin(ogen) to activation by tissue-specific plasminogen activator (tPA). Recombinant proteins constructed to mimic P60 (rP60) and P42 (rP42) also bound plasminogen at physiologically significant levels. M. hyopneumoniae surface-bound plasminogen was activated by tPA and is able to degrade fibrinogen, demonstrating the biological functionality of M. hyopneumoniae-bound plasmin(ogen) upon activation. Plasmin(ogen) was readily detected in porcine ciliated airways and plasmin levels were consistently higher in bronchoalveolar lavage fluid from M. hyopneumoniae-infected animals. Additionally, rP102 and rP42 bind fibronectin with K(D) s of 26 and 33 nM respectively and recombinant P102 proteins promote adherence to porcine kidney epithelial-like cells. The multifunctional binding ability of P102 and activation of M. hyopneumoniae-sequestered plasmin(ogen) by an exogenous activator suggests P102 plays an important role in virulence.

Mhp107 is a member of the multifunctional adhesin family of Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae is the causative pathogen of porcine enzootic pneumonia, an economically significant disease that disrupts the mucociliary escalator in the swine respiratory tract. Expression of Mhp107, a P97 paralog encoded by the gene mhp107, was confirmed using ESI-MS/MS. To investigate the function of Mhp107, three recombinant proteins, F1(Mhp107), F2(Mhp107), and F3(Mhp107), spanning the N-terminal, central, and C-terminal regions of Mhp107 were constructed. Colonization of swine by M. hyopneumoniae requires adherence of the bacterium to ciliated cells of the respiratory tract. Recent studies have identified a number of M. hyopneumoniae adhesins that bind heparin, fibronectin, and plasminogen. F1(Mhp107) was found to bind porcine heparin (K(D) ∼90 nM) in a dose-dependent and saturable manner, whereas F3(Mhp107) bound fibronectin (K(D) ∼180 nM) at physiologically relevant concentrations. F1(Mhp107) also bound porcine plasminogen (K(D) = 24 nM) in a dose-dependent and physiologically relevant manner. Microspheres coated with F3(Mhp107) mediate adherence to porcine kidney epithelial-like (PK15) cells, and all three recombinant proteins (F1(Mhp107)-F3(Mhp107)) bound swine respiratory cilia. Together, these findings indicate that Mhp107 is a member of the multifunctional M. hyopneumoniae adhesin family of surface proteins and contributes to both adherence to the host and pathogenesis.

Repeat regions R1 and R2 in the P97 paralogue Mhp271 of Mycoplasma hyopneumoniae bind heparin, fibronectin and porcine cilia.

Mycoplasma hyopneumoniae, the causative agent of porcine enzootic pneumonia, adheres to ciliated respiratory epithelia resulting in ciliostasis and epithelial cell death. The cilium adhesin P97 (Mhp183) contains two repeat regions, designated R1 and R2, that play key roles in adherence. Eight pentapeptide repeats in R1 are sufficient to bind porcine cilia; however, both R1 and R2 are needed to bind heparin. Mhp271, a paralogue of P97, is the only other M. hyopneumoniae protein to contain both R1 and R2 repeats. These repeats are arranged as a set of three pentapeptide repeats (designated R1A271), two decapeptide repeats (designated R2271), and a second set of six pentapeptide repeats (designated R1B271). To determine their function, recombinant proteins containing R1A271) (F1271) and R2271-R1B271 (F2271) were constructed and used in in vitro binding assays. F2271, but not F1271, bound heparin (K(D)=8.1 ± 0.4 nM), fibronectin (K(D)=174 ± 13 nM) and porcine cilia. Pre-incubation of F2271 with 100 µM heparin blocked cilium binding by ~69%. Cell surface shaving with trypsin combined with two-dimensional liquid chromatography coupled to tandem mass spectrometry analysis identified Mhp271 as surface-exposed. Our data suggest that both R1 and R2 in Mhp271 are involved in binding to host molecules.

A processed multidomain mycoplasma hyopneumoniae adhesin binds fibronectin, plasminogen, and swine respiratory cilia.

Porcine enzootic pneumonia is a chronic respiratory disease that affects swine. The etiological agent of the disease, Mycoplasma hyopneumoniae, is a bacterium that adheres to cilia of the swine respiratory tract, resulting in loss of cilia and epithelial cell damage. A M. hyopneumoniae protein P116, encoded by mhp108, was investigated as a potential adhesin. Examination of P116 expression using proteomic analyses observed P116 as a full-length protein and also as fragments, ranging from 17 to 70 kDa in size. A variety of pathogenic bacterial species have been shown to bind the extracellular matrix component fibronectin as an adherence mechanism. M. hyopneumoniae cells were found to bind fibronectin in a dose-dependent and saturable manner. Surface plasmon resonance was used to show that a recombinant C-terminal domain of P116 bound fibronectin at physiologically relevant concentrations (K(D) 24 ± 6 nm). Plasmin(ogen)-binding proteins are also expressed by many bacterial pathogens, facilitating extracellular matrix degradation. M. hyopneumoniae cells were found to also bind plasminogen in a dose-dependent and saturable manner; the C-terminal domain of P116 binds to plasminogen (K(D) 44 ± 5 nm). Plasminogen binding was abolished when the C-terminal lysine of P116 was deleted, implicating this residue as part of the plasminogen binding site. P116 fragments adhere to the PK15 porcine kidney epithelial-like cell line and swine respiratory cilia. Collectively these data suggest that P116 is an important adhesin and virulence factor of M. hyopneumoniae.