Impact of the dose of CsA on mitochondrial function.

<p>(A) Calcium retention capacity (CRC) 24 h after reperfusion as a function of the CsA dose. Mitochondrial PTP opening was significantly inhibited in the control versus the sham group. The CRC 24 h after reperfusion was significantly higher in the CsA 10 mg/kg-10 min group than in the control or CsA 3 mg/kg-10 min groups (*p< 0.05 vs control group).</p

Oxidative phosphorylation 24 h after reperfusion in CsA-treated, sham and control mice.

<p>Oxidative phosphorylation 24 h after reperfusion in CsA-treated, sham and control mice.</p

Impact of the dose of CsA on renal function.

<p>(A) Plasma creatinine levels, (B) histological scores 24 h after reperfusion (*p< 0.05 vs control).</p

In-hospital management.

<p>In-hospital management.</p

Blood samples collection protocol for STEMI cohort at our institution.

<p>Blood samples collection protocol for STEMI cohort at our institution.</p

Leucocytes and neutrophil granulocytes at 24 hours (H24) and their correlation with myocardial infarct size (IS).

<p><b>A</b>; Leucocytes count at H24 was significantly correlated with IS as measured by peak troponin release. <b>B</b>; At H24 neutrophil count was available for 24 patients only. For these patients, we found a significant correlation between neutrophil count and IS as measured by peak troponin release. Dotted line shows 95% confidence bands.</p

IL-17A activity assessed by ΔIL-8 on Human Umbilical Vein Endothelial Cells (HUVEC) and its correlation with infarct size (IS) in STEMI patients.

<p><b>A, B and C</b>; IL-17A activity (ΔIL-8) at H0 was not correlated with IS as measured by peak troponin level (A) (r = 0.2576, p = 0.27) peak CK level (B) (r = 0.1753, p = 0.45) or Cardiac Magnetic Resonance (CMR) (C) (r = -0.09123, p = 0.71). <b>D, E and F</b>; ΔIL-8 at H4 was not correlated with IS as measured by peak troponin level (D) (r = 0.03628, p = 0.88) peak CK level (E) (r = 0.2137, p = 0.36) or CMR (F) (r = -0.1615, p = 0.50). Correlations were tested using Spearman correlation. CK: Creatine Kinase.</p

Principal biological characteristics of the study population at admission and myocardial biomarkers peak values.

<p>Principal biological characteristics of the study population at admission and myocardial biomarkers peak values.</p

IL-17A functional test with Human Umbilical Vein Endothelial Cells (HUVEC).

<p><b>A</b>; HUVECs were incubated 48 hours with the serum of each patient. IL-8 production by HUVECs was significantly higher in STEMI patient (at H0 and at H4) compared to healthy control. <b>B</b>; HUVECs were also incubated with each patient serum in the presence of anti-IL-17A antibody (neutralizing antibody). The difference between IL-8 secretion by HUVECs without and with IL-17A neutralizing antibody (named ΔIL-8) represented the secretion of IL-8 due to IL-17A. ΔIL-8 was significantly increased at H0 for STEMI patients compare to healthy controls but not at H4. STEMI: ST-Segment Elevation Myocardial Infarction. *p<0.05, **p<0.01.</p

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<p>Antibody-mediated rejection is currently the leading cause of transplant failure. Prevailing dogma predicts that B cells differentiate into anti-donor-specific antibody (DSA)-producing plasma cells only with the help of CD4+ T cells. Yet, previous studies have shown that dependence on helper T cells decreases when high amounts of protein antigen are recruited to the spleen, two conditions potentially met by organ transplantation. This could explain why a significant proportion of transplant recipients develop DSA despite therapeutic immunosuppression. Using murine models, we confirmed that heart transplantation, but not skin grafting, is associated with accumulation of a high quantity of alloantigens in recipients’ spleen. Nevertheless, neither naive nor memory DSA responses could be observed after transplantation of an allogeneic heart into recipients genetically deficient for CD4+ T cells. These findings suggest that DSA generation rather result from insufficient blockade of the helper function of CD4+ T cells by therapeutic immunosuppression. To test this second theory, different subsets of circulating T cells: CD8+, CD4+, and T follicular helper [CD4+CXCDR5+, T follicular helper cells (Tfh)], were analyzed in 9 healthy controls and 22 renal recipients. In line with our hypothesis, we observed that triple maintenance immunosuppression (CNI + MMF + steroids) efficiently blocked activation-induced upregulation of CD25 on CD8+, but not on CD4+ T cells. Although the level of expression of CD40L and ICOS was lower on activated Tfh of immunosuppressed patients, the percentage of CD40L-expressing Tfh was the same than control patients, as was Tfh production of IL21. Induction therapy with antithymocyte globulin (ATG) resulted in prolonged depletion of Tfh and reduction of CD4+ T cells number with depleting monoclonal antibody in murine model resulted in exponential decrease in DSA titers. Furthermore, induction with ATG also had long-term beneficial influence on Tfh function after immune reconstitution. We conclude that CD4+ T cell help is mandatory for naive and memory DSA responses, making Tfh cells attractive targets for improving the prevention of DSA generation and to prolong allograft survival. Waiting for innovative treatments to be translated into the clinical field ATG induction seems to currently offer the best clinical prospect to achieve this goal.</p