Exploring the functional interaction between POSH and ALIX and the relevance to HIV-1 release

<p>Abstract</p> <p>Background</p> <p>The ALG2-interacting protein X (ALIX)/AIP1 is an adaptor protein with multiple functions in intracellular protein trafficking that plays a central role in the biogenesis of enveloped viruses. The ubiquitin E3-ligase POSH (plenty of SH3) augments HIV-1 egress by facilitating the transport of Gag to the cell membrane. Recently, it was reported, that POSH interacts with ALIX and thereby enhances ALIX mediated phenotypes in <it>Drosophila</it>.</p> <p>Results</p> <p>In this study we identified ALIX as a POSH ubiquitination substrate in human cells: POSH induces the ubiquitination of ALIX that is modified on several lysine residues <it>in vivo </it>and <it>in vitro</it>. This ubiquitination does not destabilize ALIX, suggesting a regulatory function. As it is well established that ALIX rescues virus release of L-domain mutant HIV-1, HIV-1Δ_PTAP, we demonstrated that wild type POSH, but not an ubiquitination inactive RING finger mutant (POSH^V14A), substantially enhances ALIX-mediated release of infectious virions derived from HIV-1Δ_PTAPL-domain mutant (YPX_nL-dependent HIV-1). In further agreement with the idea of a cooperative function of POSH and ALIX, mutating the YPX_nL-ALIX binding site in Gag completely abrogated augmentation of virus release by overexpression of POSH. However, the effect of the POSH-mediated ubiquitination appears to be auxiliary, but not necessary, as silencing of POSH by RNAi does not disturb ALIX-augmentation of virus release.</p> <p>Conclusion</p> <p>Thus, the cumulative results identified ALIX as an ubiquitination substrate of POSH and indicate that POSH and ALIX cooperate to facilitate efficient virus release. However, while ALIX is obligatory for the release of YPX_nL-dependent HIV-1, POSH, albeit rate-limiting, may be functionally interchangeable.</p

Trends in volumes and survival after hematopoietic cell transplantation in racial/ethnic minorities.

There has been an increase in volume as well as an improvement in overall survival (OS) after hematopoietic cell transplantation (HCT) for hematologic disorders. It is unknown if these changes have affected racial/ethnic minorities equally. In this observational study from the Center for International Blood and Marrow Transplant Research of 79 904 autologous (auto) and 65 662 allogeneic (allo) HCTs, we examined the volume and rates of change of autoHCT and alloHCT over time and trends in OS in 4 racial/ethnic groups: non-Hispanic Whites (NHWs), non-Hispanic African Americans (NHAAs), and Hispanics across 5 2-year cohorts from 2009 to 2018. Rates of change were compared using Poisson model. Adjusted and unadjusted Cox proportional hazards models examined trends in mortality in the 4 racial/ethnic groups over 5 study time periods. The rates of increase in volume were significantly higher for Hispanics and NHAAs vs NHW for both autoHCT and alloHCT. Adjusted overall mortality after autoHCT was comparable across all racial/ethnic groups. NHAA adults (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.04-1.22; P&nbsp;= .004) and pediatric patients (HR 1.62; 95%&nbsp;CI 1.3-2.03; P&nbsp;&lt; .001) had a higher risk of mortality after alloHCT than NHWs. Improvement in OS over time was seen in all 4 groups after both autoHCT and alloHCT. Our study shows the rate of change for the use of autoHCT and alloHCT is higher in NHAAs and Hispanics than in NHWs. Survival after autoHCT and alloHCT improved over time; however, NHAAs have worse OS after alloHCT, which has persisted. Continued efforts are needed to mitigate disparities for patients requiring alloHCT

Trends in volumes and survival after hematopoietic cell transplantation in racial/ethnic minorities

ABSTRACT: There has been an increase in volume as well as an improvement in overall survival (OS) after hematopoietic cell transplantation (HCT) for hematologic disorders. It is unknown if these changes have affected racial/ethnic minorities equally. In this observational study from the Center for International Blood and Marrow Transplant Research of 79 904 autologous (auto) and 65 662 allogeneic (allo) HCTs, we examined the volume and rates of change of autoHCT and alloHCT over time and trends in OS in 4 racial/ethnic groups: non-Hispanic Whites (NHWs), non-Hispanic African Americans (NHAAs), and Hispanics across 5 2-year cohorts from 2009 to 2018. Rates of change were compared using Poisson model. Adjusted and unadjusted Cox proportional hazards models examined trends in mortality in the 4 racial/ethnic groups over 5 study time periods. The rates of increase in volume were significantly higher for Hispanics and NHAAs vs NHW for both autoHCT and alloHCT. Adjusted overall mortality after autoHCT was comparable across all racial/ethnic groups. NHAA adults (hazard ratio [HR] 1.13; 95% confidence interval [CI] 1.04-1.22; P = .004) and pediatric patients (HR 1.62; 95% CI 1.3-2.03; P &lt; .001) had a higher risk of mortality after alloHCT than NHWs. Improvement in OS over time was seen in all 4 groups after both autoHCT and alloHCT. Our study shows the rate of change for the use of autoHCT and alloHCT is higher in NHAAs and Hispanics than in NHWs. Survival after autoHCT and alloHCT improved over time; however, NHAAs have worse OS after alloHCT, which has persisted. Continued efforts are needed to mitigate disparities for patients requiring alloHCT

Mobile phone-based interventions for smoking cessation

-National Institute for Health Innovation (Auckland Uniservices), New Zealand. -Cancer Council Victoria, Australia

Reevaluating Patient Eligibility for Inotuzumab Ozogamicin Based on CD22 Expression: Is Dim Expression Sufficient?

Salvage options for patients with relapsed B-cell acute lymphoblastic leukemia (B-ALL) include inotuzumab ozogamicin (InO), a recombinant, humanized anti-CD22 monoclonal antibody conjugated to the cytotoxic antibiotic calicheamicin. However, the benefit of InO in patients with dim CD22 expression remains unclear. We present a case of a patient with B-ALL who responded to InO despite only dim surface expression of CD22 by flow cytometry, achieving a survival benefit concordant with that reported in the literature and maintaining a good quality of life as a transfusion-independent outpatient. Our observation has broad relevance to clinicians who manage patients with B-ALL who are candidates for InO

The Stem Cell Drive: A Canadian Perspective

Abstract Patients with a variety of blood cancers and metabolic diseases may require a stem cell transplant as part of their treatment. However, 70% of patients do not have a suitable genetic match in their family. Stem cell donor-databases are used to match potential unrelated donors to patients worldwide. In Canada, individuals aged 17-35 years can register as donors online or at a stem cell drive where they provide consent and a tissue sample (buccal-swab) for Human Leukocyte Antigen (HLA) allele typing. To date, no guidelines have been published to recommend a process for stem cell donor recruitment at drives. Here, I outline a Canadian approach to stem cell drive design, which features evidence-based strategies to identify and recruit the most-needed stem cell donors and to minimize donor ambivalence and withdrawal from the registry. This model of stem cell drive design includes five stations: pre-screening, informed consent, registration, swabbing, and reconciliation. Registrant confidentiality and privacy is maintained at each station, and quality control is emphasized throughout. Registrants are first pre-screened to ensure donor eligibility. Recruiters at the prescreening station target the most-needed stem cell donors according to the literature: young, healthy, and ethnically-diverse males. Non-optimal and ineligible registrants are redirected to help out in other ways. Recruiters then explain the principles of stem cell donation and educate registrants about the stem cell donation process. Next, registrants proceed to the informed consent station, which is designed to meet the requirements of the World Marrow Donor Association's suggested procedures for procurement of informed consent at time of recruitment (2003). Here, recruiters hand registrants an information pamphlet, and explain blood and marrow stem cell collection procedure diagrams. The risks of donation are outlined, and registrants are informed of their right to withdraw at any time and about donor and patient anonymity. Registrants are subsequently guided through registration, where they provide their contact/demographic information, complete a health questionnaire, and sign a consent form to join the registry. Recruiters at this station error check registrants' forms to ensure correct completion, and educate registrants about the data collection, storage, usage, and confidentiality. Following registration, registrants proceed to swabbing, where they swab their cheeks to provide a tissue/DNA sample. Recruiters at this station affix barcode stickers to each swab kit component. While registrants swab their cheeks, volunteers perform an informed consent checkpoint by asking registrants if they understand the donation process, the risks involved, and the right to withdraw at any time. Finally, registrants visit reconciliation, where their paperwork is error checked again, their understanding of the donation process is assessed a final time to verify informed consent, and their kit processed for shipping. In summary, the five-station approach to stem cell drive design outlined in this presentation represents a new model for effective stem cell donor recruitment. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare. </jats:sec