Handling Errors in Public Organizations

Learning from mistakes is essential for effective organizational development and collaboration. Yet, surprisingly little is known about the underlying behavioral mechanisms that determine public agents’ likelihood to handle errors positively, that is reporting, analyzing, and learning from mistakes instead of hiding them from their supervisors and coworkers. Using experimental data from an original conjoint experiment, we disentangle the interaction between error-related, individual, and organizational factors as a basis for error response. In this we advance the theoretical understanding on the micro-foundations of error handling and we help public managers understand their employees’ behavior to foster positive error cultures in their organizations

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections—Interactions with Neutrophils, Complement, and Coagulation Pathways

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig’s modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement

Immunomodulation: Immunoglobulin Preparations Suppress Hyperinflammation in a COVID-19 Model via FcγRIIA and FcαRI

The rapid spread of SARS-CoV-2 has induced a global pandemic. Severe forms of COVID-19 are characterized by dysregulated immune response and “cytokine storm”. The role of IgG and IgM antibodies in COVID-19 pathology is reasonably well studied, whereas IgA is neglected. To improve clinical outcome of patients, immune modulatory drugs appear to be beneficial. Such drugs include intravenous immunoglobulin preparations, which were successfully tested in severe COVID-19 patients. Here we established a versatile in vitro model to study inflammatory as well as anti-inflammatory processes by therapeutic human immunoglobulins. We dissect the inflammatory activation on neutrophil-like HL60 cells, using an immune complex consisting of latex beads coated with spike protein of SARS-CoV-2 and opsonized with specific immunoglobulins from convalescent plasma. Our data clarifies the role of Fc-receptor-dependent phagocytosis via IgA-FcαRI and IgG-FcγR for COVID-19 disease followed by cytokine release. We show that COVID-19 associated inflammation could be reduced by addition of human immunoglobulin preparations (IVIG and trimodulin), while trimodulin elicits stronger immune modulation by more powerful ITAMi signaling. Besides IgG, the IgA component of trimodulin in particular, is of functional relevance for immune modulation in this assay setup, highlighting the need to study IgA mediated immune response

The Functional Role of IgA in the IgM/IgA-Enriched Immunoglobulin Preparation Trimodulin

In comparison to human immunoglobulin (Ig) G, antibodies of IgA class are not well investigated. In line with this, the functional role of the IgA component in IgM/IgA-enriched immunoglobulin preparations is also largely unknown. In recent years, powerful anti-pathogenic and immunomodulatory properties of human serum IgA especially on neutrophil function were unraveled. Therefore, the aim of our work is to investigate functional aspects of the trimodulin IgA component, a new plasma-derived polyvalent immunoglobulin preparation containing ~56% IgG, ~23% IgM and ~21% IgA. The functional role of IgA was investigated by analyzing the interaction of IgA with FcαRI, comparing trimodulin with standard intravenous IgG (IVIG) preparation and investigating Fc receptor (FcR)-dependent functions by excluding IgM-mediated effects. Trimodulin demonstrated potent immunomodulatory, as well as anti-pathogenic effects in our neutrophil model (neutrophil-like HL-60 cells). The IgA component of trimodulin was shown to induce a strong FcαRI-dependent inhibitory immunoreceptor tyrosine-based activation motif (ITAMi) signaling, counteract lipopolysaccharide-induced inflammation and mediate phagocytosis of Staphylococcus aureus. The fine-tuned balance between immunomodulatory and anti-pathogenic effects of trimodulin were shown to be dose-dependent. Summarized, our data demonstrate the functional role of IgA in trimodulin, highlighting the importance of this immunoglobulin class in immunoglobulin therapy

The Dual Role of a Polyvalent IgM/IgA-Enriched Immunoglobulin Preparation in Activating and Inhibiting the Complement System

Activation of the complement system is important for efficient clearance of a wide variety of pathogens via opsonophagocytosis, or by direct lysis via complement-dependent cytotoxicity (CDC). However, in severe infections dysregulation of the complement system contributes to hyperinflammation. The influence of the novel IgM/IgA-enriched immunoglobulin preparation trimodulin on the complement pathway was investigated in in vitro opsonophagocytosis, binding and CDC assays. Immunoglobulin levels before and after trimodulin treatment were placed in relation to complement assessments in humans. In vitro, trimodulin activates complement and induces opsonophagocytosis, but also interacts with opsonins C3b, C4b and anaphylatoxin C5a in a concentration-dependent manner. This was not observed for standard intravenous IgG preparation (IVIg). Accordingly, trimodulin, but not IVIg, inhibited the downstream CDC pathway and target cell lysis. If applied at a similar concentration range in healthy subjects, trimodulin treatment resulted in C3 and C4 consumption in a concentration-dependent manner, which was extended in patients with severe community-acquired pneumonia. Complement consumption is found to be dependent on underlying immunoglobulin levels, particularly IgM, pinpointing their regulative function in humans. IgM/IgA provide a balancing effect on the complement system. Trimodulin may enhance phagocytosis and opsonophagocytosis in patients with severe infections and prevent excessive pathogen lysis and release of harmful anaphylatoxins

Loss of hCD45⁺ or hCD3⁺ cells from the peripheral blood upon TGN1412 or OKT3 treatment.

<p>Humanized mice were injected i.v. with 20 μg OKT3 or 20 μg TGN1412 per 10 grams body weight. <b>(A)</b> Before (black bars) and 2–6 hours post OKT3 (n = 11–12) or TGN1412 (n = 18–20) application (time point of sacrifice; gray bars), percentage and composition of hCD45⁺ cells in peripheral blood of reconstituted mice were analyzed by flow cytometric analysis. PBS-treated mice (n = 12) were used as control. Each line represents an individual mouse. *** p < 0.001; n.s., not significant (paired t-test for difference after-before). <b>(B)</b> Before and 4 hours post OKT3 application (n = 3) CD3 expression on hCD4⁺ or hCD8⁺ T cells in peripheral blood of humanized mice was investigated by flow cytometric analysis. Data from one individual animal, being representative for the indicated groups, are shown. The relative number of hCD4⁺ or hCD8⁺ T cells 4 hours after OKT3 application (gray bars) is given as percentages of total hCD4⁺ or hCD8⁺ T cells, normalized to “before”. *** p < 0.001 (paired t-test for difference after-before). <b>(C)</b> CD3 expression on human CD4⁺/CD8⁺ T cells in peripheral blood of humanized mice was investigated by flow cytometric analysis after OKT3 in vivo application (n = 3; upper panel). CD3 expression on CD4⁺/CD8⁺ T cells was investigated by flow cytometry before and after in vitro stimulation of purified human T cells with coated OKT3 (n = 3; lower panel). As control, primary human T cells were left unstained (light gray-shaded curve). Data from one individual animal or independent T cell donor, being representative for the indicated groups, are shown. Data shown in (A) are taken from 5–8 independent experiments. Data shown in (B) are representative for 2, in (C) for 3 independent experiments.</p

OKT3 application selectively downmodulates CD3 on T cells in humanized mice.

<p>Humanized mice were injected i.v. with 20 μg OKT3 or 20 μg TGN1412 per 10 grams body weight. <b>(A)</b> 2–6 hours (time point of sacrifice) post OKT3 (gray bars; n = 6–16) or TGN1412 (white bars; n = 6–16) application, percentage and composition of hCD45⁺ cells in spleen, PEC, LN, and thymus of humanized mice were analyzed by flow cytometry. PBS-treated mice (black bars; n = 6–16) were used as control. *** p < 0.001; n.s., not significant (t-test, for comparison of hCD45⁺ cells adjusted according Dunnett for multiple comparisons). <b>(B)</b> 4 hours post OKT3 (n = 3) application, CD3 expression on hCD4⁺ or hCD8⁺ T cells in spleen, PEC, LN, and thymus of humanized mice was analyzed by flow cytometry. PBS-treated mice (n = 3) were used as control to adjust quadrants for definition of positive and negative cells. Data from one individual animal, being representative for the indicated groups, are shown. <b>(C)</b> 4 hours post OKT3 (n = 3) or TGN1412 (n = 3) application, mAbs bound by their target CD3 or CD28 on human CD4⁺/CD8⁺ T cells in spleen, PEC, LN, and thymus of humanized mice were analyzed by flow cytometry (black curves). In vivo receptor occupancy of CD3 or CD28 was analyzed by exogenously adding OKT3 or TGN1412 to cells isolated from spleen, PEC, LN, and thymus of in vivo mAb-treated humanized mice (dotted curve). PBS-treated mice (n = 3) were used as control (gray-shaded curves). Data from one individual animal, being representative for the indicated groups, are shown. Data shown in (A) are taken from 2–6 independent experiments. Data shown in (B) and (C) are representative for 2 independent experiments.</p

Pneumolysin induces platelet destruction, not platelet activation, which can be prevented by immunoglobulin preparations in vitro.

Community-acquired pneumonia by primary or superinfections with Streptococcus pneumoniae can lead to acute respiratory distress requiring mechanical ventilation. The pore-forming toxin pneumolysin alters the alveolar-capillary barrier and causes extravasation of protein-rich fluid into the interstitial pulmonary tissue, which impairs gas exchange. Platelets usually prevent endothelial leakage in inflamed pulmonary tissue by sealing inflammation-induced endothelial gaps. We not only confirm that S pneumoniae induces CD62P expression in platelets, but we also show that, in the presence of pneumolysin, CD62P expression is not associated with platelet activation. Pneumolysin induces pores in the platelet membrane, which allow anti-CD62P antibodies to stain the intracellular CD62P without platelet activation. Pneumolysin treatment also results in calcium efflux, increase in light transmission by platelet lysis (not aggregation), loss of platelet thrombus formation in the flow chamber, and loss of pore-sealing capacity of platelets in the Boyden chamber. Specific anti-pneumolysin monoclonal and polyclonal antibodies inhibit these effects of pneumolysin on platelets as do polyvalent human immunoglobulins. In a post hoc analysis of the prospective randomized phase 2 CIGMA trial, we show that administration of a polyvalent immunoglobulin preparation was associated with a nominally higher platelet count and nominally improved survival in patients with severe S pneumoniae-related community-acquired pneumonia. Although, due to the low number of patients, no definitive conclusion can be made, our findings provide a rationale for investigation of pharmacologic immunoglobulin preparations to target pneumolysin by polyvalent immunoglobulin preparations in severe community-acquired pneumococcal pneumonia, to counteract the risk of these patients becoming ventilation dependent. This trial was registered at www.clinicaltrials.gov as #NCT01420744

TGN1412 Induces Lymphopenia and Human Cytokine Release in a Humanized Mouse Model.

Therapeutic monoclonal antibodies (mAbs) such as the superagonistic, CD28-specific antibody TGN1412, or OKT3, an anti-CD3 mAb, can cause severe adverse events including cytokine release syndrome. A predictive model for mAb-mediated adverse effects, for which no previous knowledge on severe adverse events to be expected or on molecular mechanisms underlying is prerequisite, is not available yet. We used a humanized mouse model of human peripheral blood mononuclear cell-reconstituted NOD-RAG1-/-Aβ-/-HLADQ(tg+ or tg-)IL-2Rγc-/- mice to evaluate its predictive value for preclinical testing of mAbs. 2-6 hours after TGN1412 treatment, mice showed a loss of human CD45+ cells from the peripheral blood and loss of only human T cells after OKT3 injection, reminiscent of effects observed in mAb-treated humans. Moreover, upon OKT3 injection we detected selective CD3 downmodulation on T cells, a typical effect of OKT3. Importantly, we detected release of human cytokines in humanized mice upon both OKT3 and TGN1412 application. Finally, humanized mice showed severe signs of illness, a rapid drop of body temperature, and succumbed to antibody application 2-6 hours after administration. Hence, the humanized mouse model used here reproduces several effects and adverse events induced in humans upon application of the therapeutic mAbs OKT3 and TGN1412