HIV persistence during combination antiretroviral therapy (cART) is the principal obstacle to cure. Mechanisms responsible for persistence remain uncertain; infections may be maintained by persistence and clonal expansion of infected cells or by ongoing replication in anatomic locations with poor antiretroviral penetration. These mechanisms require different strategies for eradication, and determining their contributions to HIV persistence is essential. We used phylogenetic approaches to investigate, at the DNA level, HIV populations in blood, lymphoid, and other infected tissues obtained at colonoscopy or autopsy in individuals who were on cART for 8 to 16 years. We found no evidence of ongoing replication or compartmentalization of HIV; we did detect clonal expansion of infected cells that were present before cART. Long-term persistence, and not ongoing replication, is primarily responsible for maintaining HIV. HIV-infected cells present when cART is initiated represent the only identifiable source of persistence and is the appropriate focus for eradication.
This article analyzes the images of aging presented in five of the prime-time television programs of 1989 most watched by the elderly: Murder, She Wrote, The Golden Girls, Matlock, Jake and the Fatman, and In the Heat of the Night, all of which have central elderly characters. An examination of the title sequences reveals that earlier television stereotypes of the elderly "as more comical, stubborn, eccentric, and foolish than other characters" have been replaced by more positive stereotypes of them as powerful, affluent, healthy, active, admired, and sexy.
Combination antiretroviral therapy (cART) controls but does not eradicate HIV infection; HIV persistence is the principal obstacle to curing infections. The proportion of defective proviruses increases during cART, but the dynamics of this process are not well understood, and a quantitative analysis of how the proviral landscape is reshaped after cART is initiated is critical to understanding how HIV persists. Here, we studied longitudinal samples from HIV infected individuals undergoing long term cART using multiplexed Droplet Digital PCR (ddPCR) approaches to quantify the proportion of deleted proviruses in lymphocytes. In most individuals undergoing cART, HIV proviruses that contain gag are lost more quickly than those that lack gag. Increases in the fraction of gag-deleted proviruses occurred only after 1–2 years of therapy, suggesting that the immune system, and/or toxicity of viral re-activation helps to gradually shape the proviral landscape. After 10–15 years on therapy, there were as many as 3.5–5 times more proviruses in which gag was deleted or highly defective than those containing intact gag. We developed a provirus-specific ddPCR approach to quantify individual clones. Investigation of a clone of cells containing a deleted HIV provirus integrated in the HORMAD2 gene revealed that the cells underwent a massive expansion shortly after cART was initiated until the clone, which was primarily in effector memory cells, dominated the population of proviruses for over 6 years. The expansion of this HIV-infected clone had substantial effects on the overall proviral population.
The vaccines industry has not changed appreciably in decades regarding technology, and has struggled to remain viable, with large companies withdrawing from production. Meanwhile, there has been no let-up in outbreaks of viral disease, at a time when the biopharmaceuticals industry is discussing downsizing. The distributed manufacturing model aligns well with this, and the advent of synthetic biology promises much in terms of vaccine design. Biofoundries separate design from manufacturing, a hallmark of modern engineering. Once designed in a biofoundry, digital code can be transferred to a small-scale manufacturing facility close to the point of care, rather than physically transferring cold-chain-dependent vaccine. Thus, biofoundries and distributed manufacturing have the potential to open up a new era of biomanufacturing, one based on digital biology and information systems. This seems a better model for tackling future outbreaks and pandemics. The Vaccine Production Model Needs to ChangeThe COVID-19 crisis has cast the vaccines industry into scrutiny [1]; an industry that has been silently beleaguered for decades (https://www.who.int/immunization/programmes_systems/ procurement/mi4a/platform/module2/2019_Global_Vaccine_Market_Report.pdf?ua=1). A United States National Academy of Sciences study from 2003 [2] concluded that the amount that the nation spent on vaccines 'appears to be insignificant compared with that spent on other medical and social interventions that may have lesser social benefits.' Large company numbers that supply vaccines have steadily reduced [3]: some 80% of vaccines arise from five multinationals (https://www.who.int/immunization/programmes_systems/procurement/market/ global_supply/en/). At the heart of the problem is a tension between relatively poor financial returns to the vaccine industry and the high costs in production and R&D [4].Compared to small molecule pharmaceuticals, centralised vaccine production facilities are capital intensive [5]. Fixed costs are high [6], especially for new vaccines. For example, the need for eggs for production is at least 70 years old, is expensive and time-consuming, but difficult to replace [7]. In past high-income countries have paid a higher price until the fixed costs are amortised. Then lower-income countries have adopted vaccines as the price has dropped after paying the fixed costs. However, there is now tremendous pressure for a COVID-19 vaccine to be available for all who need it, effectively everyone. Distributed Manufacturing, a More-Sustainable Vaccine ModelThe long distribution chains of centralised vaccine production are patchy, resulting in incomplete geographical coverage [8] (Box 1). Even if there is no overall shortage, there may be where they are needed most. Centralisation of labour and production has been the norm in many industries, but in 2015 the World Economic Forum (WEF, see Glossary) put distributed manufacturing in its top ten emerging technologies for the year (https://www.weforum.org/agenda/2015/03/top- HighlightsBiofoun...
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