It is generally believed that the gag gene product of human immunodeficiency virus type 1 (HIV-1) is processed into several core proteins by a virus-specific protease. We used deletion mutation analysis to study the role of HIV-specific protease in the processing of core proteins and its requirement for viral infectivity. Several mutant genomes with deletions in the protease gene were constructed. A mammalian cell line, COS-M6, transfected with the wild-type viral genome was shown to produce virions containing processed core proteins, while COS-M6 cells transfected with two mutated genomes could express only the core protein precursor, Pr56gag. The wild-type transfectant produced infectious virus; both transfectants expressing the mutated genomes also produced virions, and one of them still retained reverse transcriptase activity. However, the mutant viral particles were devoid of infectivity. Virions with a distinct central core and an electron-dense nucleoid budded out from the plasma membrane of COS-M6 cells transfected with the wild-type genome. In contrast, noninfectious virions that budded either into cytoplasmic vacuoles or out from the plasma membrane of COS-M6 cells transfected with mutant genomes contained ring-shaped nucleoids. These results indicate that the HIV-1 protease plays a role not only in the maturation of the core proteins but also in the assembly of the virus and thus is required for viral infectivity.
Abstract Chimeric antigen receptor (CAR) - engineered natural killer (NK) cell therapy has emerged as a promising platform for adoptive immunotherapy for cancer. However, CAR-NK or CAR-T therapy so far has achieved limited efficacy in solid tumors compared with hematologic malignancies. One of the challenges is the lack of prevalent tumor-specific surface antigen target in solid tumors. Hence, we are developing a novel oncolytic vaccinia virus (VV) to deliver a dual functional glycol-immune checkpoint inhibitor and universal tumor cell marker combined with CAR-NK cell therapy to increase anti-tumor efficacy. Using the vaccinia virus deleted in both viral TK and VGF genes (vvDD) to drive the expression of a membrane-bound sialidase derived from actinomyces viscosus (avSial) under the viral late promoter, we observed efficient desialylation of both VV-infected and non-infected tumor cells, which would alleviate the suppression of sialic acid on NK and other immune cells within TME. Further, the surface bound avSial on VV-infected tumor cells can also serve as a universal target for avSial-CAR NK cells, with less concern for cross-reactivity to normal human tissues and antigen loss. We developed anti-avSial antibodies through mice immunization study. The selected single chain variable fragments (scFV) were constructed in CAR format containing CD28 CD3 ζ for co-stimulation and human IL-15 gene for better NK persistence and function. The binding affinity of anti-avSial scFv to avSialidase were further screened in CAR constructs-transfected 293T cells. The selected anti-avSial scFv CAR were packaged into gamma retroviral vectors to transduce activated and expanded NK cells derived from healthy donor peripheral blood. For proof-of-concept, target tumor cell lines A375, A549 and HT-29 expressing transmembrane sialidase and GFP were also generated. Compared with CD19 CAR NK and none transduced (NT) NK cells, avSial CAR NK had markedly increased cytotoxicity against avSial-expressing tumor cells in co-culture assays at low E:T ratios <= 1:2. Upon tumor cell rechallenge, avSial CAR NK also controlled the tumor growth significantly better than CD19 CAR NK or NT NK cells. Furthermore, avSial CAR NK completely eliminated A375 tumor spheroids expressing transmembrane sialidase whereas CD19 CAR NK or NT NK cells only transiently controlled the tumor spheroids growth. Taken together, we have developed an effective avSial targeting CAR IL15 NK that will be used to demonstrate enhanced efficacy and versatility in combination with avSial-armed VV for treatment of solid tumors. Citation Format: Xiaomei Wang, Guowei Wei, Keshav B. Karki, Winnie Chan, Mariya Viskovska, Andrew Williams, Nancy Chang, Haiyan Jiang. Developing a novel combination therapy using engineered chimeric antigen receptor natural killer cells targeting avsialidase with avsialidase-armed oncolytic vaccinia virus in solid tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6225.
Background/Aims: Conducting longitudinal research related to chronic illness in adolescents is inherently challenging due to developmental changes and psychosocial stressors. Participants in the Treatment Options for type 2 Diabetes in Adolescents and Youth clinical trial were socioeconomically disadvantaged as well. This study assessed attitudes and beliefs about retention in Treatment Options for type 2 Diabetes in Adolescents and Youth to shed light on the factors that potentially promote and detract from the likelihood of sustained participation. Methods: After an average 7.3 years of follow-up (range 4.9–9.5), Treatment Options for type 2 Diabetes in Adolescents and Youth participants completed a survey examining their perceptions of the benefits and barriers to sustained involvement in the protocol. Results: The most common reasons for staying in Treatment Options for type 2 Diabetes in Adolescents and Youth included having a strong relationship with the medical team, getting study-provided diabetes care, access to free diabetes medicine and supplies, and being part of a large study to learn more about how to care for youth-onset type 2 diabetes. The most commonly endorsed challenges included scheduling conflicts, possibly disappointing others, difficulties getting to study visits, and the occurrence of other medical issues. Conclusions: Similar to other published reports, a supportive relationship with study staff was commonly endorsed as a benefit of engagement in the longitudinal study, suggesting that rapport, staff consistency, and relationship quality are important components of optimal retention. Moreover, our findings suggest the value of trying to remove logistical barriers, such as transportation and scheduling challenges, in order to promote long-term participation in research. Further research is recommended to evaluate factors that contribute to attrition versus retention in an a priori manner within longitudinal studies, especially protocols involving cohorts that are more vulnerable to attrition due to developmental transitions and/or socioeconomic challenges. Additional efforts to optimize quantitative and qualitative measurement of barriers would also help to expand our understanding of how to optimally retain participants in longitudinal protocols.
Because of an inadequate supply of potable water, villagers of Small Liu-Chiu Isle, Ping-Tung County, Taiwan, store water in containers supporting a large population of Aedes aegypti. In 1989-96, integrated control measures against Ae. aegypti were implemented on the basis of community participation. These measures included release of mosquito larvivorous fish in the drinking water storage facilities, application of larvicides to the water storage facilities in vegetable gardens, removal of discarded and unused containers and tires, improvement of household water storage facilities, and increase of potable water supply. Before implementation of the integrated control measures in 1988, 74% of the water-containing vessels were water storage facilities, and 24% of those were infested by Ae. aegypti. In 1989, the Breteau index for the entire island, indicating the average distribution density for larval Ae. aegypti, was 53.9, as compared to an index of 1.2 in 1996. In 4 villages located at the southwest and middle of the island, Ae. aegypti nearly became extinct because of the enthusiastic participation of the community. Before the implementation of integrated control, Ae. aegypti was the dominant species in containers both inside and outside the household, but after the integrated control, Aedes albopictus became predominant outside.
In Brief A 35-year-old woman with a 4-year history of generalized Wegener granulomatosis (WG) had clinically controlled disease. She was evaluated for a 6-month history of right lacrimal sac mass. On examination, a right chronic dacryocystitis and mucocele were observed. A right external dacryocystorhinostomy was performed. The surgical biopsy specimen from the lacrimal sac showed leukocytoclastic vasculitis with more aggressive damage to the small vessels in the deeper mucosa and focal microhemorrhages. The patient was free of symptoms 1 year after surgery. We believe this is the first report of generalized WG presenting features of an active vasculitis of the lacrimal sac wall on surgical biopsy specimen. We conclude that the lacrimal drainage system can be affected directly by focal WG vasculitis, suggesting that nasolacrimal duct obstruction is not always due to contiguous paranasal disease. A case of lacrimal sac active vasculitis in a patient with generalized Wegener granulomatosis is presented.
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