image_2_Altered Humoral Immune Responses and IgG Subtypes in NOX2-Deficient Mice and Patients: A Key Role for NOX2 in Antigen-Presenting Cells.jpg

<p>Chronic granulomatous disease (CGD) is a primary immunodeficiency resulting from loss of function mutations in the reactive oxygen species generating phagocyte NADPH oxidase (NOX2). CGD patients are prone to infection, but also have an increased susceptibility to autoimmune diseases. The aim of this study was to investigate the role of NOX2 in the regulation of specific immunity. In both CGD patients and NOX2-deficient mice, we observed an alteration in the basal proportions of IgG subtypes. Upon immunization with curdlan—a dectin 1 agonist—NOX2-deficient mice showed increased production of IgG2c compared to controls, and restimulation of lymph node-derived cells led to increased production of IFNγ, but not IL-5, indicative hallmark of an enhanced Th1 response. T cell activation was increased in NOX2-deficient mice and a similar trend was observed in vitro when T cells were co-cultured with NOX2-deficient bone marrow-derived cells. In contrast, no difference in T cell activation was observed when NOX2-deficient T cells were co-cultured with wild-type BMDC. Following stimulation of NOX2-deficient dendritic cells (DCs), no difference in costimulatory molecules was observed, while there was an increase in the release of Th1-driving cytokines. In summary, both CGD patients and CGD mice have an altered IgG subtype distribution, which is associated with an increased IFNγ production. Thus, NOX2 within DCs appears to be an important regulator at the interface of innate and specific immunity, especially after activation of the dectin 1 pathway, limiting immune activation and the development of autoimmunity.</p

image_4_Altered Humoral Immune Responses and IgG Subtypes in NOX2-Deficient Mice and Patients: A Key Role for NOX2 in Antigen-Presenting Cells.jpg

<p>Chronic granulomatous disease (CGD) is a primary immunodeficiency resulting from loss of function mutations in the reactive oxygen species generating phagocyte NADPH oxidase (NOX2). CGD patients are prone to infection, but also have an increased susceptibility to autoimmune diseases. The aim of this study was to investigate the role of NOX2 in the regulation of specific immunity. In both CGD patients and NOX2-deficient mice, we observed an alteration in the basal proportions of IgG subtypes. Upon immunization with curdlan—a dectin 1 agonist—NOX2-deficient mice showed increased production of IgG2c compared to controls, and restimulation of lymph node-derived cells led to increased production of IFNγ, but not IL-5, indicative hallmark of an enhanced Th1 response. T cell activation was increased in NOX2-deficient mice and a similar trend was observed in vitro when T cells were co-cultured with NOX2-deficient bone marrow-derived cells. In contrast, no difference in T cell activation was observed when NOX2-deficient T cells were co-cultured with wild-type BMDC. Following stimulation of NOX2-deficient dendritic cells (DCs), no difference in costimulatory molecules was observed, while there was an increase in the release of Th1-driving cytokines. In summary, both CGD patients and CGD mice have an altered IgG subtype distribution, which is associated with an increased IFNγ production. Thus, NOX2 within DCs appears to be an important regulator at the interface of innate and specific immunity, especially after activation of the dectin 1 pathway, limiting immune activation and the development of autoimmunity.</p

Cytokine and chemokine responses to BCG infection.

<p>TNF-α (A), IL-17 (B), IL-12p40 (C), IFN-γ (D), CXCL1 (E) and CCL5 (F) were assessed in lung homogenates obtained 3 days and 4 weeks after BCG infection. Results are presented as the mean ± SEM (n = 4–7 mice per group). (**: p<0.05, *: p<0.01).</p

Analysis of published cases of mycobacterial infections in CGD patients.

<p>Our literature research identified a total of 297 published cases of mycobacterial disease in CGD patients. (A) Mycobacterial species recovered in mycobacterial disease in CGD patients. (B) Clinical presentations of <i>Mycobacterium bovis</i> BCG and <i>Mycobacterium tuberculosis</i> infections in CGD patients. The numbers indicated on top of each column represent the percentage with respect to the total number of BCG or <i>M. tuberculosis</i> cases, respectively. The terms “systemic” refers to disseminated or to lung infections.</p

Impact of CGD mutation on mortality and weight loss in response to BCG infection.

<p><i>Ncf1</i> mutant (loss of function mutation in p47^phox), <i>Ncf1</i> rescue (expression of wild-type p47^phox in mononuclear phagocytes) with C57Bl/10.Q background, <i>Ncf1</i> mutant (loss of function mutation in p47^phox) with C57Bl/6 background, <i>Cybb</i><b>-</b>deficient and their respective wild-type controls were injected intravenously with BCG (10⁷ CFU). Survival was monitored over the 4 weeks period following BCG inoculation in (A) C57Bl/10.Q wild-type (n = 15), <i>Ncf1</i> mutant (n = 15) and <i>Ncf1</i> rescue (n = 11), in (C) C57Bl/6 wild-type (n = 7), <i>Ncf1</i> mutant (n = 6) and (E) C57Bl/6 wild-type (n = 7), <i>Cybb</i><b>-</b>deficient (n = 9) mice. (B, D and F) Body weight changes as a function of time after BCG inoculation. Survival (percent of initial number of mice) is shown in brackets. Statistics shown in the figures are the comparison between respective wild-type and <i>Ncf1</i> mutant or <i>Cybb</i><b>-</b>deficient (***: p<0.001, **: p<0.05, *: p<0.01) and the comparison between <i>Ncf1</i> mutant and rescue (§§§: p<0.001 and §§: p<0.01). Note that no significant differences were observed between wild-type and <i>Ncf1</i> rescue mice.</p

Additional file 2 of Obstructive sleep apnea: a major risk factor for COVID-19 encephalopathy?

Additional file 2: Supplemental Table 2. Comparison of patient characteristics at the time of COVID-19 onset and COVID-19 acute encephalopathy between definite OSA group and No OSA group

Lung parameters in response to BCG infection.

<p>(A) Lung/weight ratio of wild-type (n = 9), <i>Ncf1</i> mutant (n = 5) and <i>Ncf1</i> rescue (n = 8) mice without BCG infection and at 3 days and 4 weeks post infection. (B) Determination of alveolar space score (occupied lung tissue <i>vs.</i> free space) in lung sections at 4 weeks post infection. Data are represented as the mean of alveolar space score ± SD in 4 mice per group with at least 3 lobes analyzed per mouse. (C) Number of viable bacteria was determined at 3 days and 4 weeks following BCG infection. Data are shown as mean log of CFU per organ (±SEM; 3–5 mice per group). (D) iNOS protein expression in lung was detected by western blot 4 weeks after BCG infection. Results are expressed as mean ± SEM of relative units of iNOS/actin (n = 4, per group) after quantification by Image Quant software. (E) Nitrotyrosine quantification by ELISA was done in lungs, 4 weeks after BCG infection. Results are expressed as mean ± SEM of nM per lung (n = 4–5, per group). (***: p<0.001, **: p<0.05, *: p<0.01).</p

Additional file 3 of Obstructive sleep apnea: a major risk factor for COVID-19 encephalopathy?

Additional file 3: Supplemental Table 3. Cerebrospinal fluid analyses at the time of COVID-19 acute encephalopathy

Additional file 1 of Obstructive sleep apnea: a major risk factor for COVID-19 encephalopathy?

Additional file 1: Supplemental Table 1. Comparison of patient demographic characteristics between definite OSA group and No OSA group