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Background As of mid-June 2020, 7,500,000 people were infected with SARS-CoV-2 worldwide and 420,000 people died, mainly from coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS). COVID-19-related ARDS is subject to a mortality rate of 50% and prolonged period of mechanical ventilation, with no specific pharmacological treatment currently available (Infection au nouveau Coronavirus (SARS-CoV-2), COVID-19, France et Monde. https://www.santepubliquefrance.fr/dossiers/coronavirus-covid-19). Because of its immunomodulatory action, we propose to evaluate the efficacy and safety of intravenous immunoglobulin (IVIG) administration in patients developing COVID-19-related ARDS. Methods The trial is a phase III double-blind, randomized, multicenter, parallel group, concurrent, controlled study in hospitalized participants with COVID-19 requiring mechanical ventilation using a sequential design. Participants in the treatment group will receive infusions of polyvalent immunoglobulin for 4 consecutive days, and the placebo group will receive an equivalent volume of sodium chloride 0.9% for the same duration. The primary outcome is the number of ventilator-free days up to the 28th day. Secondary objectives are to evaluate the effect of IVIG on (1) organ failure according to the Sequential Organ Failure Assessment (SOFA) score at 14 and 28 days, (2) lung injury score at 14 and 28 days, (3) the occurrence of grade 3 or 4 adverse events of IVIG, (4) length of intensive care unit (ICU) stay, (5) length of hospital stay, (6) functional outcomes at day 90 defined by the activities of daily living and instrumental activities of the daily living scales, and (7) 90-day survival. One hundred thirty-eight subjects will be randomized in a 1:1 ratio to IVIG or placebo groups (69 in each group), considering 90% power, alpha level 0.05 (two sides), and 0.67 effect size level. Discussion The ICAR trial investigates the effect of IVIG in COVID-19-related ARDS. We expect an increase in the survival rate and a reduction in the duration of mechanical ventilation, which is associated with significant morbidity. Trial registration EudraCT 2020-001570-30. ClinicalTrials.gov NCT04350580. Registered on 17 April 2020

International audience; The constitutive expression of major histocompatibility complex class II (MHC II) molecules in melanoma is highly unusual and has been associated with unfavorable clinical outcome and higher metastatic dissemination. This association remains poorly understood and therefore, in this study we looked to whether it is caused by intracellular events that promote tumor progression. We previously reported that MHC II expression in melanoma cells requires active mitogen-activated protein kinase/extracellular signal-related kinase. However, our comparative and molecular analyses of a panel of melanoma cell lines herein provide clear evidence that mitogen-activated protein kinase/extracellular signal-related kinase is not sufficient for HLA-DR expression. We found that the expression of HLA-DR in these tumors rather coincides with the expression of CXCL-1 and CXCL-8 chemokines, both known to be expressed in tumors that invade early and are related to invasive stages of melanoma. The expression of HLA-DR also nicely paralleled that of the nuclear NFkappaB p50 subunit, regulating the expression of these chemokines in melanoma and previously correlated with poor prognosis of melanoma patients, although we provide evidence that NFkappaB is not directly regulating MHC II expression level. The molecular basis for class II transactivator and HLA-DR expression in melanoma therefore remains unsolved, but our findings linking together the expression of HLA-DR, of chemokines involved in invasiveness, and of nuclear NFkappaB p50 strongly support the content that MHC II may be a marker of invasive primary melanoma, and could explain the long-standing association of MHC II expression with overall poor prognosis and unfavorable clinical outcome.

Resistance of malignant melanoma cells to Fas-mediated apoptosis is among the mechanisms by which they escape immune surveillance. However, the mechanisms contributing to their resistance are not completely understood, and it is still unclear whether antiapoptotic Bcl-2–related family proteins play a role in this resistance. In this study, we report that treatment of Fas-resistant melanoma cell lines with cycloheximide, a general inhibitor of de novo protein synthesis, sensitizes them to anti-Fas monoclonal antibody (mAb)–induced apoptosis. The cycloheximide-induced sensitization to Fas-induced apoptosis is associated with a rapid down-regulation of Mcl-1 protein levels, but not that of Bcl-2 or Bcl-xL. Targeting Mcl-1 in these melanoma cell lines with specific small interfering RNA was sufficient to sensitize them to both anti-Fas mAb-induced apoptosis and activation of caspase-9. Furthermore, ectopic expression of Mcl-1 in a Fas-sensitive melanoma cell line rescues the cells from Fas-mediated apoptosis. Our results further show that the expression of Mcl-1 in melanoma cells is regulated by the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) and not by phosphatidylinositol 3-kinase/AKT signaling pathway. Inhibition of ERK signaling with the mitogen-activated protein/ERK kinase-1 inhibitor or by expressing a dominant negative form of mitogen-activated protein/ERK kinase-1 also sensitizes resistant melanoma cells to anti-Fas mAb-induced apoptosis. Thus, our study identifies mitogen-activated protein kinase/ERK/Mcl-1 as an important survival signaling pathway in the resistance of melanoma cells to Fas-mediated apoptosis and suggests that its targeting may contribute to the elimination of melanoma tumors by the immune system. (Mol Cancer Res 2008;6(1):42–52)

International audience; The class II transactivator (CIITA) is the master regulator of MHC class II molecules (MHC II). In melanoma, the MHC II are constitutively expressed due to an abnormal transcription of CIITA from its promoter III (pIII), and requires the presence of a 1-kb enhancer located upstream from this latter. Since mitogen-activated protein kinases (MAPK) have been shown to be activated in most melanomas, we sought to analyze their possible involvement in CIITA expression. Using chemical inhibitors and dominant-negative constructs of MAPK-ERK kinase (Mek1) and MAPK-JNK, we evidenced the inhibition of MHC II and CIITA expression in melanoma cell lines displaying activated MAPK. Transcriptional regulation by MAPK is known to involve the AP-1 transcription factor family. Sequence analysis revealed an AP-1-responsive motif in the enhancer of CIITA pIII at -5954/-5947 from the site of transcription initiation. Its mutagenesis reduced CIITA expression four- to fivefold in melanoma cell lines and alleviated the effect of dominant-negative constructs of the MAPK pathway. Together, our findings demonstrate that MAPK-ERK and MAPK-JNK are regulators of CIITA transcription in melanoma, and pinpoint an AP-1-responsive site in the CIITA gene pIII. This should have considerable impact on our understanding of the physio-pathologic expression of MHC II.