Rapid Pivot of CURE Wet Lab to Online with the Help of Instructor Communities.

The pivot to remote and hybrid learning during the Covid-19 pandemic presented a challenge for many in academia. Most institutions were not prepared to support this rapid change, and instructors were left with the burden of converting a traditional face-to-face course into multiple modalities with very limited preparation time. When institutional support is lacking, we posit that instructor communities of practice can help provide the resources needed to meet the instructional demands. Tiny Earth, a course-based-undergraduate research experience (CURE) and international network of instructors and students, responded to the instructional challenges of the pandemic by leveraging its large community of instructors to create several smaller working groups to form focused communities of practice. Using the pedagogical principles of backward design and scientific teaching, one working group, the Tiny Earth Pivot Group (Pivot Group) generated a course map of remote learning activities and simulated learning resources to fulfill the Tiny Earth learning objectives and maintain the essential tenets of a CURE. Additional working groups were created to disseminate the resources collated and created by the Pivot Group to the greater community. In terms of Tiny Earth, the community structure provided the means for instructors to rapidly pivot their course materials to multiple modalities while upholding the student CURE experience. Harnessing the hallmarks of communities of practice-collective workpower toward common purpose, diversity of perspectives, and ongoing evolution-coupled with high-structured course design allows instructors flexibility and adaptability in meeting the changing modalities of higher education.

A Crucial Role for Antimicrobial Stewardship in the Midst of COVID-19.

As the world deals with a pandemic, there remains another global challenge that cannot be ignored. Use of broad-spectrum antibiotics may be justified as we are trying to treat a novel disease condition, which in turn could lead to an increase in antimicrobial resistance. We can decrease morbidity, mortality, and health care costs by controlling antimicrobial resistance, but it requires antimicrobial stewardship. Major components of effective and timely antimicrobial stewardship are diagnostic stewardship, infection prevention and control, and integration of COVID-19 specific flags into electronic health records, all of which may be integrated into current strategies of COVID-19 mitigation and management. Going through the influenza season of 2020, implementation of antimicrobial stewardship education efforts in the United States can help us contend with influenza in addition to COVID-19 and any bacterial co-infections or secondary infections. Additional solutions include the development of vaccines, alternative therapies such as antibodies, and advanced diagnostics using advances in genomics and computer science.

The role of Neuropilin-1 in COVID-19.

Neuropilin-1 (NRP-1), a member of a family of signaling proteins, was shown to serve as an entry factor and potentiate SARS Coronavirus 2 (SARS-CoV-2) infectivity in vitro. This cell surface receptor with its disseminated expression is important in angiogenesis, tumor progression, viral entry, axonal guidance, and immune function. NRP-1 is implicated in several aspects of a SARS-CoV-2 infection including possible spread through the olfactory bulb and into the central nervous system and increased NRP-1 RNA expression in lungs of severe Coronavirus Disease 2019 (COVID-19). Up-regulation of NRP-1 protein in diabetic kidney cells hint at its importance in a population at risk of severe COVID-19. Involvement of NRP-1 in immune function is compelling, given the role of an exaggerated immune response in disease severity and deaths due to COVID-19. NRP-1 has been suggested to be an immune checkpoint of T cell memory. It is unknown whether involvement and up-regulation of NRP-1 in COVID-19 may translate into disease outcome and long-term consequences, including possible immune dysfunction. It is prudent to further research NRP-1 and its possibility of serving as a therapeutic target in SARS-CoV-2 infections. We anticipate that widespread expression, abundance in the respiratory and olfactory epithelium, and the functionalities of NRP-1 factor into the multiple systemic effects of COVID-19 and challenges we face in management of disease and potential long-term sequelae.

Impact of pyriproxyfen on virus behavior: implications for pesticide-induced virulence and mechanism of transmission.

BACKGROUND: More than 3 years since the last Zika virus (ZIKV) outbreak in Brazil, researchers are still deciphering the molecular mechanisms of neurovirulence and vertical transmission, as well as the best way to control spread of ZIKV, a flavivirus. The use of pesticides was the main strategy of mosquito control during the last ZIKV outbreak. METHODS: We used vesicular stomatitis virus (VSV) tagged with green fluorescent protein (GFP) as our prototypical virus to study the impact of insecticide pyriproxyfen (PPF). VZV-GFP infected and uninfected Jurkat, HeLa and trophoblast cells were treated with PPF and compared to untreated cells (control). Cell viability was determined by the MTT assay. Cell morphology, presence of extracellular vesicles (EVs), virus infection/GFP expression as well as active mitochondrial levels/localization were examined by confocal microscopy. RESULTS: PPF, which was used to control mosquito populations in Brazil prior to the ZIKV outbreak, enhances VSV replication and has cell membrane-altering properties in the presence of virus. PPF causes enhanced viral replication and formation of large EVs, loaded with virus as well as mitochondria. Treatment of trophoblasts or HeLa cells with increasing concentrations of PPF does not alter cell viability, however, it proportionately increases Jurkat cell viability. Increasing concentrations of PPF followed by VSV infection does not interfere with HeLa cell viability. Both Jurkats and trophoblasts show proportionately increased cell death with increased concentrations of PPF in the presence of virus. CONCLUSIONS: We hypothesize that PPF disrupts the lipid microenvironment of mammalian cells, thereby interfering with pathways of viral replication. PPF lowers viability of trophoblasts and Jurkats in the presence of VSV, implying that the combination renders immune system impairment in infected individuals as well as enhanced vulnerability of fetuses towards viral vertical transmission. We hypothesize that similar viruses such as ZIKV may be vertically transmitted via EV-to-cell contact when exposed to PPF, thereby bypassing immune detection. The impact of pesticides on viral replication must be fully investigated before large scale use in future outbreaks of mosquito borne viruses.

Science Alive!: Connecting with Elementary Students through Science Exploration.

A novel program called Science Alive! was developed by undergraduate faculty members, K-12 school teachers, and undergraduate students to enrich science, technology, engineering, and mathematics (STEM) literacy at community schools located near the university. The ultimate goal of the program is to bolster the scientific knowledge and appreciation of local area students and community members and serve as a model for similar programs. Through the program, we observed that elementary school students made gains toward learning their grade-level science curricula after a hands-on learning experience and had fun doing these hands-on activities. Through the program, undergraduate students, working with graduate students and alumni, build scientific learning modules using explanatory handouts and creative activities as classroom exercises. This helps better integrate scientific education through a collaborative, hands-on learning program. Results showed that elementary school students made the highest learning gains in their performance on higher-level questions related to both forces and matter as a result of the hands-on learning modules. Additionally, college students enjoyed the hands-on activities, would consider volunteering their time at such future events, and saw the service learning program as a benefit to their professional development through community building and discipline-specific service. The science modules were developed according to grade-level curricular standards and can be used year after year to teach or explain a scientific topic to elementary school students via a hands-on learning approach.

Access of antibody molecules to the conserved coreceptor binding site on glycoprotein gp120 is sterically restricted on primary human immunodeficiency virus type 1.

Anti-human immunodeficiency virus type 1 (HIV-1) antibodies whose binding to gp120 is enhanced by CD4 binding (CD4i antibodies) are generally considered nonneutralizing for primary HIV-1 isolates. However, a novel CD4i-specific Fab fragment, X5, has recently been found to neutralize a wide range of primary isolates. To investigate the precise nature of the extraordinary neutralizing ability of Fab X5, we evaluated the abilities of different forms (immunoglobulin G [IgG], Fab, and single-chain Fv) of X5 and other CD4i monoclonal antibodies to neutralize a range of primary HIV-1 isolates. Our results show that, for a number of isolates, the size of the neutralizing agent is inversely correlated with its ability to neutralize. Thus, the poor ability of CD4i-specific antibodies to neutralize primary isolates is due, at least in part, to steric factors that limit antibody access to the gp120 epitopes. Studies of temperature-regulated neutralization or fusion-arrested intermediates suggest that the steric effects are important in limiting the binding of IgG to the viral envelope glycoproteins after HIV-1 has engaged CD4 on the target cell membrane. The results identify hurdles in using CD4i epitopes as targets for antibody-mediated neutralization in vaccine design but also indicate that the CD4i regions could be efficiently targeted by small molecule entry inhibitors.

Interaction of HIV reverse transcriptase with structures mimicking recombination intermediates.

Interactions between human immunodeficiency virus (HIV) reverse transcriptase (RT) and structures mimicking intermediates proposed to occur during recombination (strand transfer) were investigated. One mechanism proposed for strand transfer is strand exchange in which a homologous RNA (acceptor) "invades" a donor RNA.DNA duplex (replication intermediate) on which DNA synthesis is occurring. The acceptor displaces the donor of the duplex and binds to the DNA. During exchange a transient trimeric structure forms. A model structure was designed with a replication intermediate to which an acceptor RNA was bound. The acceptor was bound to the 5'-end of the DNA over a 54-base region, whereas the donor associated with the DNA 3'-end over a 28-base region. The dimeric constituents of the trimer (acceptor RNA.DNA and donor RNA.DNA) were also constructed. The acceptor RNA.DNA formed a branched structure in this case. Results showed that RT could cleave the RNA portion of all the structures examined. Association with junction substrates was less stable as determined by off-rates. On the trimer, RT cleaved both RNAs but showed a clear preference for cleaving the donor RNA region. This preference was accentuated by HIV nucleocapsid protein (NC). Results suggest that during recombination RT generally associates with the donor-RNA portion of the trimer and the acceptor RNA is protected but not immune from cleavage. The partial protection likely allows the acceptor RNA to more easily complete strand exchange and shield this RNA to provide a means to salvage replication if the DNA were to dissociate from the cleaved donor RNA.

CD4 binding site antibodies inhibit human immunodeficiency virus gp120 envelope glycoprotein interaction with CCR5.

The human immunodeficiency virus type 1 (HIV-1) gp120 exterior glycoprotein is conformationally flexible. Upon binding the host cell receptor, CD4, gp120 assumes a conformation that is able to bind the chemokine receptors CCR5 or CXCR4, which act as coreceptors for the virus. CD4-binding-site (CD4BS) antibodies are neutralizing antibodies elicited during natural infection that are directed against gp120 epitopes that overlap the binding site for CD4. Recent studies (S. H. Xiang et al., J. Virol. 76:9888-9899, 2002) suggest that CD4BS antibodies recognize conformations of gp120 distinct from the CD4-bound conformation. This predicts that the binding of CD4BS antibodies will inhibit chemokine receptor binding. Here, we show that Fab fragments and complete immunoglobulin molecules of CD4BS antibodies inhibit CD4-independent gp120 binding to CCR5 and cell-cell fusion mediated by CD4-independent HIV-1 envelope glycoproteins. These results are consistent with a model in which the binding of CD4BS antibodies limits the ability of gp120 to assume a conformation required for coreceptor binding.