Afucosylated IgG characterizes enveloped viral responses and correlates with COVID-19 severity

Immunoglobulin G (IgG) antibodies are crucial for protection against invading pathogens. A highly conserved N-linked glycan within the IgG-Fc tail, which is essential for IgG function, shows variable composition in humans. Afucosylated IgG variants are already used in anticancer therapeutic antibodies for their increased activity through Fc receptors (Fc gamma RIIIa). Here, we report that afucosylated IgG (approximately 6% of total IgG in humans) are specifically formed against enveloped viruses but generally not against other antigens. This mediates stronger Fc gamma RIIIa responses but also amplifies brewing cytokine storms and immune-mediated pathologies. Critically ill COVID-19 patients, but not those with mild symptoms, had high concentrations of afucosylated IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), amplifying proinflammatory cytokine release and acute phase responses. Thus, antibody glycosylation plays a critical role in immune responses to enveloped viruses, including COVID-19.Proteomic

Correlação entre teores de nitrogênio e de clorofila na folha com o rendimento de grãos de aveia branca Correlation among nitrogen and chlorophyll contents of leaves and grain yield of oat

Um experimento foi conduzido na Universidade de Passo Fundo (UPF) com o objetivo de avaliar as correlações entre teores de N e de clorofila em folhas de aveia branca e entre estes e o rendimento de grãos (RG), massa de mil grãos (MMG), período de enchimento (PEG) e taxa de enchimento de grãos (TEG). O ensaio foi conduzido no ano agrícola de 2003, utilizando-se 21 cultivares de aveia branca desenvolvidas pela FAMV/UPF, distribuídas em blocos ao acaso, em quatro repetições. Estimou-se o teor de clorofila por meio do índice SPAD (clorofilômetro) e determinou-se o seu teor pelo método químico e também os teores de N, nas folhas bandeia e bandeira-1, no estádio de antese. Na maturação (colheita), determinou-se o RG, o MMG, o TEG e o PEG. Verificou-se que não houve correlações significativas entre teores de clorofila com os teores de N, com RG, MMG, TEG e PEG, porém, houve correlações significativas entre teores de N com o RG, MMG e PEG.<br>An experiment was conducted at the Passo Fundo University, with the aim of evaluate the correlations among nitrogen contents, chlorophyll contents, grain yield (GY), thousand grain weight (TGW), grain filling period (GFP) and grain filling rate (GFR) in oat cultivars. The experiment was conducted during 2003 agriculture year, with oat cultivars developed by Passo Fundo University, with four replications, at random blocks distribution. The chlorophyll contents, estimated by chlorophyll meter (SPAD 502 model) and chemical method, and nitrogen contents were determined at anthesis stage. At maturation stage, the GY, TGW, GFP and GFR variables were determined. It was observed that there were no significant correlations among chlorophyll contents with nitrogen contents, with GY, TGW and GFP, but there were significant correlations among nitrogen contents and GY, TGW and GFP