Rice Big Grain1 enhances biomass and plant growth-promoting traits in rhizospheric yeast Candida tropicalis.

The Big Grain1 (BG1) gene of rice (Oryza sativa L.) is reported to increase the yield of rice crops; however, its molecular mechanism is largely concealed. To explore its functional prospects, we have taken a structure-function-based approach. In silico analyses suggest OsBG1 is a DNA- and phytohormone-binding protein. Heterologous expression of OsBG1 with galactose-inducible promoter GAL1p in the rhizospheric yeast Candida tropicalis SY005 revealed 7.9- and 1.5-fold higher expression of the gene at 12 and 24 h, respectively, compared to the expression at 36 h post-galactose induction. Functional activity of the induced OsBG1 in engineered yeast increased cell density, specific growth rate, and biomass by 28.5%, 29.8%, and 14.1%, respectively, and decreased the generation time by 21.25%. Flow cytometry-based cell cycle analysis of OsBG1-expressing yeast cells exhibited an increase in the cells of the G2/M population by 15.8% after 12 h of post-galactose induction. The gene expression study of yeast transformants disclosed that OsBG1 regulates cell division by upregulating the expression of the endogenous gene cyclin B1 (CtCYB1) by 1.3- and 1.9-folds at 10 and 12 h, respectively, compared to the control, and is positively influenced by the phytohormone indole acetic acid (IAA). Further, the study revealed that OsBG1 significantly increases biofilm formation, stress tolerance, and IAA production in C. tropicalis SY005, implying its prospective role in enhancing plant growth-promoting traits in microbes. OsBG1-expressing rhizospheric yeast cells significantly improved the germination and growth parameters of the bio-inoculated rice seeds. Altogether, this study suggests OsBG1 can be employed to genetically improve suitable bio-inoculants for their plant growth-promoting traits to augment crop productivity. KEY POINTS: • In silico analyses suggested OsBG1 is a phytohormone-binding transcription factor. • OsBG1 enhanced growth in rhizospheric Candida tropicalis by upregulating CtCYB1. • OsBG1 improved plant growth-promoting traits of the rhizospheric yeast C. tropicalis.

Activation and differentiation of cognate T cells by a dextran-based antigen-presenting system for cancer immunotherapy.

Immunotherapeutic modulation of antigen-specific T-cell responses instead of the whole repertoire helps avoid immune-related adverse events. We have developed an artificial antigen-presenting system (aAPS) where multiple copies of a multimeric peptide-MHC class I complex presenting a murine class I MHC restricted ovalbumin-derived peptide (signal 1), along with a costimulatory ligand (signal 2) are chemically conjugated to a dextran backbone. Cognate naive CD8+ T cells, when treated with this aAPS underwent significant expansion and showed an activated phenotype. Furthermore, elevated expression of effector cytokines led to the differentiation of these cells to cytotoxic T lymphocytes which resulted in target cell lysis, indicative of the functional efficacy of the aAPS. CD8+ T cells with decreased proliferative potential due to repeated antigenic stimulation could also be re-expanded by the developed aAPS. Thus, the developed aAPS warrants further engineering for future application as a rapidly customizable personalized immunotherapeutic agent, incorporating patient-specific MHC-restricted tumor antigens and different costimulatory signals to modulate both naive and antigen-experienced but exhausted tumor-specific T cells in cancer.

Plasma therapy: a passive resistance against the deadliest.

Convalescent plasma therapy provides a useful therapeutic tool to treat infectious diseases, especially where no specific therapeutic strategies have been identified. The ongoing pandemic puts back the spotlight on this age-old method as a viable treatment option. In this review, we discuss the usage of this therapy in different diseases including COVID-19, and the possible mechanisms of action. The current review also discusses the progress of therapeutic applications of blood-derivatives, from the simple transfer of immunized animal sera, to the more target-specific intravenous administration of human immunoglobulins from a pool of convalescent individuals, in both infectious and non-infectious diseases of various etiologies.

Hospital mortality among COVID-19 patients - Experience of a multi-disciplinary tertiary care teaching hospital of Chhattisgarh in Central India.

Introduction: The mortality from coronavirus disease 2019 (COVID-19) infection and the severity of it vary among populations. There is a dearth of research on epidemiology and clinical outcomes in central Indian populations with COVID-19. Our aim was to provide an analysis of all hospitalized mortality among patients with COVID-19 infection in a tertiary care hospital of Chhattisgarh in central India. This analysis helped us to know the severity predictors for mortality and in future will help the authorities to formulate a plan to decrease the mortality in the epidemic or uncertain ongoing pandemic. Methodology: This was a retrospective observational study using the hospital-based record of multi-disciplinary teaching hospital in Chhattisgarh, India. All COVID-19 reverse-transcriptase polymerase chain reaction-positive patients who were declared dead or died during the course of treatment from April 1, 2020 to March 31, 2021 were included in the study. In-hospital mortality was the primary outcome of interest. In secondary analysis, age and gender distribution, co-morbidity, length of stay, and the cause of death were also investigated. Results: A total of 7495 patients with a confirmed diagnosis of COVID-19 were enrolled in the study, of whom 762 (10.16%) died in the hospital with COVID-19 as the primary cause of death. The majority of the patients were more than 60 years of age (45.7%). A total of 416 (54.4%) of the deceased patients were having co-morbidity with diabetes (13.4%), hypertension (16.4%), or both (24.4%). The majority of the patients who succumbed had a hospital stay of less than a week (≤7) (68.5%). More than half of the patients (58.3%) who expired had referred and reported to the hospital in the second or third week of illness. The respiratory system involvement was the dominant contributor of death with pneumonia (78.8%) being the most common cause, followed by acute respiratory distress syndrome (62.2%). 13.6% of expired patients had multiple system involvement, and 11.2% had sepsis as well. Conclusion: Mortality in COVID-19 patients was associated with advanced age, co-morbidities such as diabetes and hypertension, and delay in hospitalization. These are high-risk groups and should be vaccinated against COVID-19 on priority.