Search

Abstract Background One reason why subunit protein and DNA vaccines are often less immunogenic than live-attenuated and whole-inactivated virus vaccines is that they lack the co-stimulatory signals provided by various components of the more complex vaccines. The HIV-1 envelope glycoprotein complex (Env) is no exception to this rule. Other factors that limit the induction of neutralizing antibodies against HIV-1 lie in the structure and instability of Env. We have previously stabilized soluble trimeric mimics of Env by introducing a disulfide bond between gp120 and gp41 and adding a trimer stabilizing mutation in gp41 (SOSIP.R6 gp140). Results We further stabilized the SOSIP.R6 gp140 using a GCN4-based isoleucine zipper motif, creating SOSIP.R6-IZ gp140. In order to target SOSIP.R6-IZ to immune cells, including dendritic cells, while at the same time activating these cells, we fused SOSIP.R6-IZ to the active domain of CD40 ligand (CD40L), which may serve as a 'cis-adjuvant'. The Env component of the SOSIP.R6-IZ-CD40L fusion construct bound to CD4 and neutralizing antibodies, while the CD40L moiety interacted with CD40. Furthermore, the chimeric molecule was able to signal efficiently through CD40 and induce maturation of human dendritic cells. Dendritic cells secreted IL-6, IL-10 and IL-12 in response to stimulation by SOSIP.R6-IZ-CD40L and were able to activate naïve T cells. Conclusions Chimeric HIV-1 gp140 - CD40L trimers can target and activate dendritic cells. Targeting and activating immune cells using CD40L and other 'cis-adjuvants' may improve subunit protein vaccine immunogenicity for HIV-1 and other infectious diseases.

Abstract Background The HIV-1 envelope glycoprotein gp120, which mediates viral attachment to target cells, consists for ~50% of sugar, but the role of the individual sugar chains in various aspects of gp120 folding and function is poorly understood. Here we studied the role of the carbohydrate at position 386. We identified a virus variant that had lost the 386 glycan in an evolution study of a mutant virus lacking the disulfide bond at the base of the V4 domain. Results The 386 carbohydrate was not essential for folding of wt gp120. However, its removal improved folding of a gp120 variant lacking the 385–418 disulfide bond, suggesting that it plays an auxiliary role in protein folding in the presence of this disulfide bond. The 386 carbohydrate was not critical for gp120 binding to dendritic cells (DC) and DC-mediated HIV-1 transmission to T cells. In accordance with previous reports, we found that N386 was involved in binding of the mannose-dependent neutralizing antibody 2G12. Interestingly, in the presence of specific substitutions elsewhere in gp120, removal of N386 did not result in abrogation of 2G12 binding, implying that the contribution of N386 is context dependent. Neutralization by soluble CD4 and the neutralizing CD4 binding site (CD4BS) antibody b12 was significantly enhanced in the absence of the 386 sugar, indicating that this glycan protects the CD4BS against antibodies. Conclusion The carbohydrate at position 386 is not essential for protein folding and function, but is involved in the protection of the CD4BS from antibodies. Removal of this sugar in the context of trimeric Env immunogens may therefore improve the elicitation of neutralizing CD4BS antibodies.

Background: While gastrointestinal (GI) dysfunction is commonly encountered among critically ill patients, a uniform prospectively validated scoring system is lacking. The present study aims to validate the recently developed Gastrointestinal Dysfunction Score (GIDS) in a multicenter, prospective cohort of consecutive adult patients admitted to intensive care units (ICU)., Methods: GUTPHOS is a prospective, multicenter, non-interventional cohort study in which at least 1400 consecutive adult patients (age ≥18 years) admitted to the ICU will be monitored daily for abdominal signs and symptoms of GI dysfunction. The previously developed GIDS constructed from these signs and symptoms will be tested in relation to mortality and duration of ICU dependency and parenteral nutrition (PN) dependency. Between January and June 2024, each participating clinical site will include 50-120 consecutive patients over an eight-week period. Study data will be collected in three phases: baseline data upon ICU admission, daily observations throughout a maximum of 7 days in ICU or until discharge, and a follow-up period of 90 days. The primary outcomes are 28- and 90-day all-cause mortality. Secondary outcomes include ICU and hospital mortality, ICU and hospital length of stay, days alive and free of ICU by day 28 and day 90, days alive and free of hospital by day 28 and day 90, and days alive and free of organ support and PN dependency by day 28., Discussion: The GUTPHOS study will be the first worldwide, multicenter, prospective, observational cohort study to validate the GIDS in adult patients admitted to ICUs against 28- and 90-day mortality. The availability of a validated tool will allow its use in interventional studies that are currently hindered by the lack of a validated measurement tool for GI dysfunction., Clinical Trial Registry: NCT05909722., Competing Interests: Declaration of competing interest IWKK received a Veni Fellowship (2024–2028) through the Dutch Research Council (NWO Talent Program). SJS received grants and non-financial support from Reactive Robotics GmbH (Munich, Germany), ASP GmbH (Attendorn, Germany), STIMIT AG (Biel, Switzerland), ESICM (Geneva, Switzerland), grants, personal fees, and non-financial support from Fresenius Kabi Deutschland GmbH (Bad Homburg, Germany), grants from the Innovationsfond of The Federal Joint Committee (G-BA), personal fees from Springer Verlag GmbH (Vienna, Austria) for educational purposes and Advanz Pharma GmbH (Bielefeld, Germany), non-financial support from national and international societies (and their congress organizers) in the field of anesthesiology and intensive care medicine, outside the submitted work. SJS holds stocks in small amounts from Alphabet Inc., Bayer AG, and Siemens AG; these holdings have not affected any decisions regarding his research or this study. ARHvZ reported receiving honoraria for advisory board meetings, lectures, research, and travel expenses from Abbott, AOP Pharma, Baxter, Cardinal Health, Danone-Nutricia, Fresenius Kabi, GE Healthcare, Medcaptain, Nestlé, PAION, and Rousselot. ARB received speaker or consulting fees from Nutricia and VIPUN Medical. JG is granted a senior clinical investigator fellowship by Research Foundation – Flanders (1842724N) and has obtained research funding through grants from KU Leuven (STG/23/032) and the European Society of Intensive Care Medicine (Fundamental Research Award 2022). MPC has obtained research funding by grants from Research Foundation Flanders, KU Leuven and Department for Innovation of the Flanders Government, and reported receiving consulting fees from Baxter and VIPUN. MLNGM reported receiving honoraria for advisory board meetings, lectures, research, and travel expenses from Getinge, Serenno Medical, Potrero Medical, Sentinel Medical, Baxter, BBraun, Becton Dickinson, ConvaTec, Spiegelberg, Medtronic, MedCaptain, and Holtech Medical, and PeerVoice. He holds stock options for Sentinel, Serenno and Potrero. The other authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Aberrations in blood phosphate (Pi) levels, whether presenting as hypo- or hyperphosphatemia, appear to be associated with clinical complications and adverse outcomes in patients admitted to an intensive care unit (ICU). However, the prevalence of Pi disorders and the association with subsequent factors and organ failures leading to death in ICU patients are poorly described. Despite endeavors to understand the etiology and treatment of low Pi levels from systematic reviews and meta-analyses, the literature lacks comprehensive guidance for managing hypophosphatemia. Hyperphosphatemia, on the other hand, appears to be associated with higher mortality among critically ill patients, yet its prevalence among ICU patients, particularly following phosphate repletion, remains unknown. The present study aims to investigate the prevalence of Pi abnormalities upon ICU admission and their incidence during the first week of ICU stay, the factors associated with Pi alterations, and the effect of phosphate repletion on the normalization of Pi levels, and its associations with clinical outcomes., Methods: This multicentre, prospective, non-interventional cohort study will include at least 1000 consecutive adult ICU patients (≥18 years) as part B of the GUTPHOS study. Sites are eligible if an anticipated minimal inclusion of 50 eligible patients during eight weeks from January 2024 until June 2024 and daily phosphate measurements during the first seven days of ICU stay are expected. All consecutive adult patients admitted to a participating ICU during the recruitment period, lasting up to eight weeks, or up to 120 patients if enrollment reaches that limit earlier, will be included. Study parameters include study site characteristics, patient demographics, daily assessment of Pi levels, Pi-related treatment, feeding details, renal replacement therapy details, the incidence of refeeding-associated hypophosphatemia and administered medication (during the first seven calendar days of ICU stay). There will be a follow-up period of a maximum of 90 days to document 28- and 90-day all-cause mortality as the primary outcome. Multiple logistic regression will be used to assess independent associations with mortality in addition to Receiver Operating Characteristics curves to identify cut-off Pi values associated with mortality and overcorrection. Linear mixed models will be conducted to assess Pi treatment effects. Subgroup analyses will be performed based on Pi abnormalities observed during ICU admission, categorized as normo-, hypo-, hyper-, or mixed, along with its severity (mild, moderate, or severe)., Discussion: The GUTPHOS study will be the first multicentre, prospective observational cohort study to investigate the prevalence, management practices, and consequent outcomes associated with Pi abnormalities during the first week of ICU admission. Its results may bridge the current evidence gap in repletion protocols while establishing the groundwork for a subsequent randomized controlled trial., Clinical Trial Registry: NCT05909722., Competing Interests: Declaration of competing interest IWKK received a Veni Fellowship (2024–2028) through the Dutch Research Council (NWO Talent Program). SJS received grants and non-financial support from Reactive Robotics GmbH (Munich, Germany), ASP GmbH (Attendorn, Germany), STIMIT AG (Biel, Switzerland), ESICM (Geneva, Switzerland), grants, personal fees, and non-financial support from Fresenius Kabi Deutschland GmbH (Bad Homburg, Germany), grants from the Innovationsfond of The Federal Joint Committee (G-BA), personal fees from Springer Verlag GmbH (Vienna, Austria) for educational purposes and Advanz Pharma GmbH (Bielefeld, Germany), non-financial support from national and international societies (and their congress organizers) in the field of anesthesiology and intensive care medicine, outside the submitted work. SJS holds stocks in small amounts from Alphabet Inc., Bayer AG, and Siemens AG; these holdings have not affected any decisions regarding his research or this study. ARHvZ reported receiving honoraria for advisory board meetings, lectures, research, and travel expenses from Abbott, AOP Pharma, Baxter, Cardinal Health, Danone-Nutricia, Fresenius Kabi, GE Healthcare, Medcaptain, Nestlé, PAION, and Rousselot. ARB received speaker or consulting fees from Nutricia and VIPUN Medical and is holding a grant from Estonian Research Council (PRG1255). MPC has obtained research funding by grants from Research Foundation Flanders, KU Leuven and Department for Innovation of the Flanders Government, and reported receiving consulting fees from Baxter and VIPUN. MLNGM reported receiving honoraria for advisory board meetings, lectures, research, and travel expenses from Getinge, Serenno Medical, Potrero Medical, Sentinel Medical, Baxter, BBraun, Becton Dickinson, ConvaTec, Spiegelberg, Medtronic, MedCaptain, and Holtech Medical, and PeerVoice. He holds stock options for Sentinel, Serenno and Potrero. JG is granted a senior clinical investigator fellowship by Research Foundation – Flanders (1842724N), and has obtained research funding by grants from KU Leuven (STG/23/032) and the European Society of Intensive Care Medicine (Fundamental Research Award 2022). The other authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background & Aims: Malnutrition is prevalent among COVID-19 patients admitted to the intensive care unit (ICU) and it is associated with poor survival. Customized nutrition plays a vital role in enhancing outcomes for this patient population. This study explores the association between energy and protein intake and 90-day mortality in invasively mechanically ventilated COVID-19 patients, utilizing fat-free mass (FFM) and actual body weight (ABW) for nutritional requirements. Furthermore, the study investigates the occurrence of gastrointestinal (GI) intolerance in critically ill COVID-19 patients in relation to their nutritional intake and survival., Methods: A retrospective study was undertaken at a university-affiliated teaching hospital, focusing on COVID-19 patients on invasive mechanical ventilation admitted to the ICU between March 2020 and December 2021. The study collected demographic and clinical data, along with cumulative energy and protein goals, and recorded cumulative intake on days 4, 7, and throughout the ICU stay. Univariate and multivariable Cox regression analyses were conducted to evaluate associations between energy and protein deficits and the 90-day all-cause mortality., Results: The study included 85 patients, of whom 67 (78 %) survived 90 days after ICU admission. There were no significant differences in body composition between survivors and non-survivors. Reaching ≥70 % of the energy goal based on both ABW and FFM during the ICU stay was associated with decreased 90-day mortality (HR 0.22, 95 % CI 0.08-0.60 and HR 0.28, 95 % CI 0.09-0.85, respectively). Similarly, achieving ≥80 % of the protein target based on FFM was associated with decreased 90-day mortality (HR 0.26, 95 % CI 0.07-0.94), whereas no significant association was found for reaching protein targets based on ABW (HR 0.03, 95 % CI 0.00-3.40). Patients who reached both their energy and protein goal based on FFM during ICU admission showed a lower risk of all-cause 90-day mortality compared to those who received <70 % of the energy goal and <80 % of protein based on FFM after adjusting for age (aHR 0.12, 95 % CI 0.03-0.50). No differences in GI intolerance related symptoms between COVID-19 survivors and non-survivors were observed., Conclusions: This study underscores the significance of providing adequate nutritional therapy to COVID-19 ICU patients who require IMV. Meeting over 80 % of the protein goals based on BIA-derived FFM was associated with lower mortality rates, which emphasizes the need for further investigation into the role of FFM in establishing nutritional targets., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose of Review: To better understand the established associations between hypocalcaemia and clinical outcomes, we synopsize the mechanisms involved in hypocalcaemia in the critically ill. We also provide an overview of the current evidence on managing hypocalcaemia in critical illness., Recent Findings: Hypocalcaemia is reported to occur in 55-85% of ICU patients. It appears to be associated with poor outcomes. It appears to be associated with poor outcomes, but it may be a marker rather than a direct cause of disease severity. The recommendations to correct calcium in major bleeding are found on weak evidence and require further exploration by a randomized controlled trial (RCT). Calcium administration in cardiac arrest has shown no benefit and may provoke harm. In addition, no RCT has assessed the risks and benefits of calcium supplementation in critically ill hypocalcemic patients. Several recent studies conclude that it may even harm septic ICU patients. These observations are supported by evidence that septic patients using calcium channel blockers may have better outcomes., Summary: Hypocalcaemia is common in critically ill patients. Direct evidence that calcium supplementation improves their outcomes is lacking, and there is even some indication that it may be detrimental. Prospective studies are required to elucidate the risks and benefits, and the pathophysiological mechanisms involved., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)