Potent Enhancement of HIV-1 Replication by Nef in the Absence of SERINC3 and SERINC5

It has recently emerged that HIV-1 Nef counteracts the antiviral host proteins SERINC3 and SERINC5. In particular, SERINC5 inhibits the infectivity of progeny virions when incorporated. SERINC3 and SERINC5 are also counteracted by the unrelated murine leukemia virus glycosylated Gag (glycoGag) protein, which possesses a potent Nef-like activity on HIV-1 infectivity. We now report that a minimal glycoGag termed glycoMA can fully substitute for Nef in promoting HIV-1 replication in Jurkat T lymphoid cells, indicating that Nef enhances replication in these cells mainly by counteracting SERINCs. In contrast, the SERINC antagonist glycoMA was unable to substitute for Nef in MOLT-3 T lymphoid cells, in which HIV-1 replication was highly dependent on Nef, and remained so even in the absence of SERINC3 and SERINC5. As in MOLT-3 cells, glycoMA was unable to substitute for Nef in stimulating HIV-1 replication in primary human cells. Although the ability of Nef mutants to promote HIV-1 replication in MOLT-3 cells correlated with the ability to engage endocytic machinery and to downregulate CD4, Nef nevertheless rescued virus replication under conditions where CD4 downregulation did not occur. Taken together, our observations raise the possibility that Nef triggers the endocytosis of a novel antiviral factor that is active against both laboratory-adapted and primary HIV-1 strains. IMPORTANCE The Nef protein of HIV-1 and the unrelated glycoGag protein of a murine leukemia virus similarly prevent the uptake of antiviral host proteins called SERINC3 and SERINC5 into HIV-1 particles, which enhances their infectiousness. We now show that although both SERINC antagonists can in principle similarly enhance HIV-1 replication, glycoGag is unable to substitute for Nef in primary human cells and in a T cell line called MOLT-3. In MOLT-3 cells, Nef remained crucial for HIV-1 replication even in the absence of SERINC3 and SERINC5. The pronounced effect of Nef on HIV-1 spreading in MOLT-3 cells correlated with the ability of Nef to engage cellular endocytic machinery and to downregulate the HIV-1 receptor CD4 but nevertheless persisted in the absence of CD4 downregulation. Collectively, our results provide evidence for a potent novel restriction activity that affects even relatively SERINC-resistant HIV-1 isolates and is counteracted by Nef

A Practical Approach to the Initiation, Titration and Intensification of Insulin Therapy in Adults with Diabetes in the Indian Context: Recommendations by Association of Clinical Endocrinologists Consensus Group

Insulin therapy is critical for people with type 1 diabetes (T1D). Although oral antidiabetic drugs (OADs) remain the mainstay of treatment for people with type 2 diabetes (T2D) in the early stages, insulin therapy becomes essential as the disease progresses to sustain life. Whilst there are guidelines and consensus statements from reputed institutions and medical bodies pertaining to diabetes mellitus (DM), there is not a dedicated guideline or consensus statement that is based on an evidence-based grading system that deals exclusively with the “Practical Approach to the Initiation, Titration and Intensification of Insulin Therapy in Adults with Diabetes in the Indian Context”, guiding general physicians and general practitioners. Hence, this consensus statement uses the modified Delphi method.The Association of Clinical Endocrinologists is a nonprofit, non-commercial body registered in India, that serves as a platform for like-minded Endocrinologists who aspire to work for the cause of the science of Diabetes and Endocrinology, its utility and application for the betterment of the health of the people and the country. The authors request the readers to please do not confuse this Association of Clinical Endocrinologists with the American College of Endocrinology/American Association of Clinical Endocrinologists (ACE/AACE) of the United States of America (USA)

Mental health transition plans for older adolescents with autistic spectrum disorders – clinical profile of patients from a metropolitan Borough, North West of England

IntroductionThe needs of people with Autistic Spectrum Conditions (ASC) are varied and complex. In order to improve outcomes for Adults with Autism, it is important to understand and evaluate the transition planning process and current services for adolescents/young Adults with ASC.Aims and objectivesAim was to undertake the needs assessment audit of all young people (ages 16–19) open to a Child and Adolescent Mental Health Service. Objectives was to ensure that transition/discharge plan was in place for all the open cases and also identify any gaps in service provision.MethodsA retrospective case-note review of all open cases (n = 41) aged 16–19 was undertaken. Data was obtained on diagnosis, co morbid problems, educational status, and transition/discharge plans.ResultsTwenty-two percent of the cases had co morbid moderate to severe Intellectual Disability. Transition was not an issue for this group, with entitlement of support from secondary-care-teams. Seventy-eight percent of the cases had diagnosis of Asperger's Syndrome (AS)/high functioning autism (HFA). Seventy-five percent had co-morbid depressive/anxiety disorders, 12% had ADHD and 10% presented with repeated self-harm/suicidal behaviour. Nature of the co-morbid problems/risks did not meet thresholds for Community Adult Secondary Mental Health Services resulting in discharge to Primary Health Care Services.ConclusionsBetter training to equip primary care staff, such as General Practitioners is needed to support the growing numbers of young adults with HFA/Asperger's syndrome being discharged to their care. Costs/benefits of providing specialist adult services for people with HFA and AS to be considered in order to improve outcomes for adults with autism.Disclosure of interestThe author has not supplied his/her declaration of competing interest.</jats:sec

Screening Sleep Abnormalities in Children with Prader–Willi Syndrome: Challenges in the Indian Scenario

There is a high prevalence of sleep-related breathing disorders in the form of obstructive and central sleep apnea as well as spontaneous oxygen desaturation in children with Prader–Willi syndrome (PWS). Most cases are asymptomatic and if untreated go on to develop unfavorable neurodevelopmental, cardiovascular, and cerebrovascular outcomes. Hence, sleep study or polysomnography (PSG) is recommended in all children at the time of diagnosis as well as with the development of certain risk factors including symptoms of sleep apnea, before and after initiation of recombinant growth hormone (rGH) therapy. The use of rGH in children with PWS has been shown to improve central sleep apnea but also shown to be associated with worsening of OSA. PSG is ideally performed in a sleep laboratory. Various types of PSG devices are available depending on the biological parameters that are desired to be monitored. Sleep disorders in children are distinct from those seen in adults and have different diagnostic scoring criteria necessitating a trained pediatric sleep specialist to analyze the PSG recording. Through the clinical case vignette of a 14-year-old girl with PWS, severe obesity, and sleep disordered breathing, this review aims to highlight the need, timing, types, analysis, and interpretation of sleep studies in infants and older children with PWS, particularly in relation to rGH therapy. There is a paucity of literature on sleep studies in children with PWS in the local setting. Thus this review also suggests the need for adapting the existing Western guidelines for PSG in Indian children with PWS.</jats:p

Relationships between MA-RNA binding in cells and suppression of HIV-1 Gag mislocalization to intracellular membranes

ABSTRACTThe HIV-1 Gag matrix (MA) domain mediates localization of Gag to the plasma membrane (PM), the site for infectious virion assembly. The MA highly basic region (HBR) interacts with phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2], a PM-specific acidic lipid. MA-HBR also binds RNAs. To test whether acidic lipids alone determine PM-specific localization of Gag or whether MA-RNA binding also plays a role, we compared a panel of MA-HBR mutants that contain two types of substitutions at MA residues 25/26 or 29/31: Lys-&gt;Arg (KR) (25/26KR and 29/31KR) and Lys-&gt;Thr (KT) (25/26KT and 29/31KT). Consistent with the importance of the HBR charge in RNA binding, both KT mutants failed to bind RNA via MA efficiently unlike the corresponding KR mutants. Both 25/26KT Gag-YFP and 29/31KT Gag-YFP bound non-specifically to PM and intracellular membranes, presumably via the myristoyl moiety and remaining MA basic residues. In contrast, 25/26KR Gag-YFP bound specifically to the PM, suggesting a role for the total positive charge and/or MA-bound RNA in navigating Gag to the PM. Unlike 29/31KT Gag-YFP, 29/31KR Gag-YFP was predominantly cytosolic and showed little intracellular membrane binding despite having a higher HBR charge. Therefore, it is likely that MA-RNA binding blocks promiscuous Gag membrane binding in cells. Notably, introduction of a heterologous multimerization domain restored PI(4,5)P2-dependent PM-specific localization for 29/31KR Gag-YFP, suggesting that the blocking of PM binding is more readily reversed than that of intracellular membrane binding. Altogether, these cell-based data support a model in which MA-RNA binding ensures PM-specific localization of Gag via suppression of non-specific membrane binding.IMPORTANCEThe PM-specific localization of HIV-1 Gag is a crucial early step in the infectious progeny production. The interaction between the MA highly basic region (HBR) of Gag and the PM-specific lipid PI(4,5)P2 is critical for Gag localization to the PM. Additionally,in vitroevidence has indicated that MA-RNA binding prevents non-specific binding of Gag to non-PI(4,5)P2-containing membranes. However, cell-based evidence supporting a role for HIV-1 MA-RNA binding in PM-specific subcellular localization has been scarce; thus, it remained possible that in cells, just the high basic charge or the PI(4,5)P2-binding ability is sufficient for MA to direct Gag specifically to the PM. The current study revealed for the first time an excellent correlation between RNA binding of MA-HBR and inhibition of promiscuous Gag localization, both within the cells, and thereby provided cell-based evidence supporting a mechanism in which HIV-1 MA binding to RNA ensures specific localization of Gag to the PM.</jats:sec

Advances in the Synthesis and Antisense Technology Applications of Bridged Nucleic Acid Monomers

: Bridged Nucleic Acids (BNA) or Locked Nucleic Acids (LNA) belong to a class of nucleic acid modification that is obtained by connecting the 2'-O and 4'-C of ribose sugar using a methylene bridge. This ‘bridging or locking’ of ribose sugar has a tremendous impact on the biological and biophysical properties of therapeutic nucleic acids. They have enhanced stability against nucleases and also have a higher binding affinity for the target RNA. Owing to these advantages, BNA is one of the most preferred nucleic acids modifications of antisense oligonucleotides (ASOs). However, the synthesis of BNA monomers is lengthy and low-yielding and requires extensive protection and deprotection of the sugar functionalities. In this article, we aim to review challenges associated with their synthesis and discuss recent chemical, chemo-enzymatic, and transglycosylation strategies employed for the efficient and cost-effective synthesis of BNA monomers and selected BNA analogues. </jats:sec