In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
We generated a monoclonal antibody, RG-1, that binds to highly conserved L2 residues 17 to 36 and neutralizes human papillomavirus 16 (HPV16) and HPV18. Passive immunotherapy with RG-1 was protective in mice. Antiserum to the HPV16 L2 peptide comprising residues 17 to 36 (peptide 17-36) neutralized pseudoviruses HPV5, HPV6, HPV16, HPV 18, HPV31, HPV 45, HPV 52, HPV 58, bovine papillomavirus 1, and HPV11 native virions. Depletion of HPV16 L2 peptide 17-36-reactive antibodies from cross-neutralizing rabbit and human L2-specific sera abolished cross-neutralization and drastically reduced neutralization of the cognate type. This cross-neutralization of diverse HPVs associated with cervical cancer, genital warts, and epidermodysplasia verruciformis suggests the possibility of a broadly protective, peptide-based vaccine.Minor capsid antigen L2 is a possible alternative to highly multivalent L1 virus-like-particle (VLP) vaccines to obtain broad protection against oncogenic human papillomaviruses (HPVs) (16). Vaccination with L2 as a full-length protein or as polypeptides protects animals against homologous-type viral challenges at both cutaneous and mucosal sites (2-4, 6, 12). Protection is not mediated by cellular immunity, suggesting the importance of neutralizing antibodies (5, 7). L2 is subdominant in the context of L1/L2 VLPs (19), but antibodies elicited by recombinant L2 immunogens are able to neutralize a remarkably broad range of HPV genotypes (15). This suggests that neutralizing epitopes of L2 may be conserved across HPV types due to some critical viral function (13). Furthermore, it raises the possibility that a single L2 protein-or peptide-based vaccine might provide comprehensive protection against the HPV types causing genital cancer and genital warts and possibly even those associated with cutaneous warts and epidermodysplasia verruciformis (EV).Identification of neutralizing epitopes within HPV16 L2. The rational design of a broadly protective L2-based preventive vaccine requires knowledge of the relevant neutralizing epitopes. To identify the neutralizing epitopes in L2, we vaccinated BALB/c mice with full-length six-His-tagged HPV16 L2 protein and produced hybridomas by using standard procedures (18). Of the 100 supernatants reactive with L2 protein, only 45 reacted with HPV16 L1/L2 pseudovirions, and only one (RG-1) neutralized HPV16 pseudovirus and was cloned. The RG-1 supernatant exhibited a neutralizing titer of 1,280 and also reacted with HPV16 L1/L2 pseudivirions by an enzyme-linked immunosorbent assay (ELISA). RG-1 and another four monoclonal antibodies (MAbs) that showed the highest ELISA reactivities with HPV16 pseudovirions were all the immunoglobulin G1() [IgG1()] isotype and reacted with HPV16 L2 protein by Western blotting (Table 1).Each MAb was screened for reactivity with 56 20-mer peptides of HPV16 L2 that overlapped each other by 12 amino acids ( Table 1). The neutralizing MAb RG-1 reacted with a peptide comprising residues 17 to 36 of HPV 16 L2 (peptide 17-36) (Fig. 1A) but not the ...
Phosphodiesterases (PDEs) regulate cyclic nucleotide levels. Increased cyclic AMP (cAMP) signaling has been associated with PRKAR1A or GNAS mutations and leads to adrenocortical tumors and Cushing syndrome. We investigated the genetic source of Cushing syndrome in individuals with adrenocortical hyperplasia that was not caused by known defects. We performed genome-wide SNP genotyping, including the adrenocortical tumor DNA. The region with the highest probability to harbor a susceptibility gene by loss of heterozygosity (LOH) and other analyses was 2q31-2q35. We identified mutations disrupting the expression of the PDE11A isoform-4 gene (PDE11A) in three kindreds. Tumor tissues showed 2q31-2q35 LOH, decreased protein expression and high cyclic nucleotide levels and cAMP-responsive element binding protein (CREB) phosphorylation. PDE11A codes for a dual-specificity PDE that is expressed in adrenal cortex and is partially inhibited by tadalafil and other PDE inhibitors; its germline inactivation is associated with adrenocortical hyperplasia, suggesting another means by which dysregulation of cAMP signaling causes endocrine tumors.
The type 1alpha regulatory subunit (RIalpha) of cAMP-dependent protein kinase (PKA) (coded by the PRKAR1A gene) is the main component of type I PKA, which regulates most of the serine-threonine kinase activity catalyzed by the PKA holoenzyme in response to cAMP. Carney complex (CNC), or the complex of spotty skin pigmentation, myxomas, and endocrine overactivity, is a multiple endocrine (and not only) neoplasia syndrome that is due to PRKAR1A-inactivating mutations. The R1alpha protein and PRKAR1A mRNA have been found to be up-regulated in a series of cell lines and human and rodent neoplasms, suggesting this molecule's involvement in tumorigenesis and its potential role in cell cycle regulation, growth, and/or proliferation. Alterations in PKA activity elicit a variety of effects depending on the tissue, developmental stage, degree of differentiation, and cAMP levels. In addition, RIalpha may have functions independent of PKA. The presence of inactivating germline mutations and the loss of its wild-type allele in some CNC lesions indicate that PRKAR1A might function as a tumor suppressor gene in these tissues, but could PRKAR1A be a classic tumor suppressor gene? Probably not, and this review explains why.
Prenatal influenza exposure increases the risk for schizophrenia and brings to question how other respiratory viruses may contribute to neuropsychiatric disease etiopathology. Human coronaviruses cause respiratory infections that range in seriousness from common colds to severe acute respiratory syndrome. Like influenza, coronaviruses can be neurotropic. To test for associations between coronaviruses and serious mental disorders, we utilized a recently developed assay and measured immunoglobulin G (IgG) response against 4 human coronavirus strains (229E, HKU1, NL63, and OC43) in 106 patients with a recent onset of psychotic symptoms and 196 nonpsychiatric controls. We expressed results quantitatively as antibody levels and qualitatively as seroprevalence relative to a defined seropositivity cutoff value. Patient IgG levels were higher than controls for HKU1, NL63, and OC43, with HKU1 and NL63 both showing highly significant patient-to-control differences (HKU1, P ≤ .002; NL63, P ≤ .00001). All 4 coronaviruses were more seroprevalent in patients vs controls, with greatest intergroup differences observed for HKU1 (93% vs 77%, P ≤ .0001). HKU1 and NL63 associations with the patient group were further supported by multivariate analyses that controlled for age, gender, race, socioeconomic status, and smoking status (HKU1, odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.03-1.67, P ≤ .027; NL63, OR = 2.42, 95% CI = 1.25-4.66, P ≤ .008). Among patients, NL63 was associated with schizophrenia-spectrum (OR = 3.10, 95% CI = 1.27-7.58, P ≤ .013) but not mood disorders. HKU1 and NL63 coronavirus exposures may represent comorbid risk factors in neuropsychiatric disease. Future studies should explore links between the timing of coronavirus infections and subsequent development of schizophrenia and other disorders with psychotic symptoms.
The use of critical-for-life organs (e.g., liver or lung) for systemic gene therapeutics can lead to serious safety concerns. To circumvent such issues, we have considered salivary glands (SGs) as an alternative gene therapeutics target tissue. Given the high secretory abilities of SGs, we hypothesized that administration of low doses of recombinant adeno-associated virus (AAV) vectors would allow for therapeutic levels of transgene-encoded secretory proteins in the bloodstream. We administered 10 9 particles of an AAV vector encoding human erythropoietin (hEPO) directly to individual mouse submandibular SGs. Serum hEPO reached maximum levels 8 -12 weeks after gene delivery and remained relatively stable for 54 weeks (longest time studied). Hematocrit levels were similarly increased. Moreover, these effects proved to be vector dose-dependent, and even a dosage as low as 10 8 particles per animal led to significant increases in hEPO and hematocrit levels. Vector DNA was detected only within the targeted SGs, and levels of AAV copies within SGs were highly correlated with serum hEPO levels (r ؍ 0.98). These results show that SGs appear to be promising targets with potential clinical applicability for systemic gene therapeutics.
Coronaviruses cause respiratory infections ranging from common colds to severe acute respiratory syndrome (SARS) in humans. Estimates for exposure to non-SARS coronaviruses are high, particularly for 229E and OC43; however, less information regarding seroprevalence is available for HKU1 and NL63. To measure exposure rates to these four coronavirus strains (229E, HKU1, NL63, and OC43), we devised an immunoassay based on amino-and carboxy-terminally tagged recombinant coronavirus nucleocapsid antigens. Four human and one feline coronavirus antigen were cloned into baculoviruses expressed in insect cells and recovered proteins bound in the solid phase of an enzyme-linked immunosorbent assay-based system. We screened sera from 10 children and 196 adults and established primary cutoff points based on immunoglobulin G (IgG) antibody levels of the predominantly seronegative children. The proportion of seropositive adults for each coronavirus was as follows: 229E, 91.3%; HKU1, 59.2%; NL63, 91.8%; and OC43, 90.8%. No evidence of a significant serological response to the feline coronavirus was observed. Significant associations of coronavirus seropositivity and antibody levels with age, gender, race, socioeconomic status, smoking status, and season of the blood draw were tested with chi-square and regression analyses. The group II coronaviruses (OC43 and HKU1) were significantly associated with race (P < 0.009 and P < 0.03, respectively). Elevated OC43 IgG levels were further significantly associated with smoking status (P < 0.03), as were high NL63 titers with socioeconomic status (P < 0.04). The high-level immunoreactivity of each coronavirus was significantly associated with the summer season (P < 0.01 to 0.0001). In summary, high rates of exposure to 229E, NL63, and OC43 and a moderate rate of exposure to HKU1 characterized the seroprevalence among individuals in this population. Demographic factors, such as race, smoking status, and socioeconomic status, may confer an increased risk of susceptibility to these viruses.Human coronaviruses primarily replicate within the respiratory tract and cause infections ranging from common colds to severe acute respiratory syndrome (SARS) (7, 13). Coronaviruses are single-stranded RNA viruses with outer envelopes that have distinct crown-like morphologies. Non-SARS respiratory infections occur from group I and group II coronaviruses, the prototypes of which (229E and OC43) were first described in the 1960s (4, 9, 18). More recently isolated human coronaviruses described in 2004 and 2005 include NL63, which is a member of group I, and HKU1, which is a member of group II (20, 21). Although current evidence suggests a worldwide distribution of these four coronaviruses (14, 19), seroprevalence studies showing relative exposure rates among the viral strains are lacking.We developed serological assays specific for each non-SARS human coronavirus (229E, HKU1, NL63, and OC43) and a feline coronavirus, which is not known to cause infections in humans. Antigen targets for these assays were t...
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