Manuel Rodríguez-Zapata

Statins Inhibit HIV-1 infection by down-regulating rho activity

Human immunodeficiency virus (HIV)-1 infectivity requires actin-dependent clustering of host lipid raft–associated receptors, a process that might be linked to Rho guanosine triphosphatase (GTPase) activation. Rho GTPase activity can be negatively regulated by statins, a family of drugs used to treat hypercholesterolemia in man. Statins mediate inhibition of Rho GTPases by impeding prenylation of small G proteins through blockade of 3-hydroxy-3-methylglutaryl coenzyme A reductase. We show that statins decreased viral load and increased CD4+ cell counts in acute infection models and in chronically HIV-1–infected patients. Viral entry and exit was reduced in statin-treated cells, and inhibition was blocked by the addition of l-mevalonate or of geranylgeranylpyrophosphate, but not by cholesterol. Cell treatment with a geranylgeranyl transferase inhibitor, but not a farnesyl transferase inhibitor, specifically inhibited entry of HIV-1–pseudotyped viruses. Statins blocked Rho-A activation induced by HIV-1 binding to target cells, and expression of the dominant negative mutant RhoN19 inhibited HIV-1 envelope fusion with target cell membranes, reducing cell infection rates. We suggest that statins have direct anti–HIV-1 effects by targeting Rho.

Liposomal Amphotericin B and Amphotericin B-Deoxycholate Show Different Immunoregulatory Effects on Human Peripheral Blood Mononuclear Cells

Conventional preparations of amphotericin B (AmB) at established therapeutic doses are known to increase nonspecific immune responses. It remains to be established whether higher doses of the less toxic liposomal preparation of AmB maintains a beneficial effect on the immune response to fungal infections. Examination of the effect of treatment of human peripheral blood mononuclear cells from healthy subjects with various doses of both liposomal AmB (L-AmB) and deoxycholate AmB (d-AmB) on proliferation, cell viability, and percentage of apoptosis demonstrated that, although both L-AmB and d-AmB at low doses significantly increased nonspecific proliferative responses, L-AmB, but not d-AmB, treatment maintained this beneficial effect at higher doses. High doses of d-AmB, but not L-AmB, resulted in significantly decreased cell viability and increased apoptosis. This study provides further evidence in healthy human subjects for choosing L-AmB over conventional preparations in the clinical treatment of fungal infections requiring systemic high-dose treatment with AmB.

Circulating sICAM-1 and sE-Selectin as biomarker of infection and prognosis in patients with systemic inflammatory response syndrome☆

BACKGROUND Vascular endothelium activation is a key pathogenic step in systemic inflammatory response syndrome (SIRS) that can be triggered by both microbial and sterile proinflammatory stimuli. The relevance of soluble adhesion molecules as clinical biomarkers to discriminate between infectious and non-infectious SIRS, and the individual patient prognosis, has not been established. METHODS We prospectively measured by sandwich ELISA, serum levels of soluble E-Selectin (sE-Selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble intercellular adhesion molecule-2 (sICAM-2) at ICU admission and at days 3, 7, 14 and 28 in patients with sepsis and at days 3 and 7 in patients with non-infectious SIRS. RESULTS At ICU admission, sE-Selectin, sVCAM-1 and sICAM-1 in patients with infectious SIRS were significantly higher than those found in patients with non-infectious SIRS. ROC analysis revealed that the AUC for infection identification was best for sICAM-1 (0.900±0.041; 95% CI 0.819-0.981; p<0.0001). Moreover, multivariate analysis showed that 4 variables were significantly and independently associated with mortality at 28 days: male gender (OR 15.90; 95% CI, 2.54-99.32), MODS score (OR 5.60; 95% CI, 1.67-18.74), circulating sE-Selectin levels (OR 4.81; 95% CI, 1.34-17.19) and sVCAM-1 concentrations (OR 4.80; 95% CI, 1.34-17.14). CONCLUSIONS Patients with SIRS secondary to infectious or non-infectious etiology show distinctive patterns of disturbance in serum soluble adhesion molecules. Serum ICAM-1 is a reliable biomarker for classifying patients with infectious SIRS from those with non-infectious SIRS. In addition, soluble E-Selectin is a prognostic biomarker with higher levels in patients with SIRS and fatal outcome.

Human Brucellosis Is Characterized by an Intense Th1 Profile Associated with a Defective Monocyte Function

ABSTRACT In animal models, a defective Th1 response appears to be critical in the pathogenesis of brucellosis, but the Th1 response in human brucellosis patients remains partially undefined. Peripheral blood from 24 brucellosis patients was studied before and 45 days after antibiotherapy. Twenty-four sex- and age-matched healthy donors were analyzed in parallel. Significantly increased levels of interleukin 1β (IL-1β), IL-2, IL-4, IL-6, IL-12p40, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), but not of IL-10, in serum and/or significantly increased percentages of samples with detectable levels of these cytokines, measured by enzyme-linked immunosorbent assays (ELISA), were found for untreated brucellosis patients, but these levels were reduced and/or normalized after treatment. Flow cytometry studies showed that the intracytoplasmic expression of IFN-γ, IL-2, and TNF-α, but not that of IL-4, by phorbol myristate-activated CD4+ CD3+ and CD8+ CD3+ T lymphocytes was significantly increased in untreated brucellosis patients and was also partially normalized after antibiotherapy. The percentage of phagocytic cells, the mean phagocytic activity per cell, and the phagocytic indices for monocytes at baseline were defective and had only partially reverted at follow-up. T lymphocytes from untreated brucellosis patients are activated in vivo and show Th1 cytokine production polarization, with strikingly high serum IFN-γ levels. In spite of this Th1 environment, we found deficient effector phagocytic activity in peripheral blood monocytes.

AN EXTRACT OF THE FERN POLYPODIUM LEUCOTOMOS INHIBITS HUMAN PERIPHERAL BLOOD MONONUCLEAR CELLS PROLIFERATION IN VITRO

An alcoholic extract of the fern polypodium leucotomos (PLE) has been empirically used as an immunosuppressor for the treatment of several autoimmune diseases. In this paper, we investigated the effects of PLE on activation and proliferative responses of peripheral blood mononuclear cells (PBMNC) from healthy donors to T lymphocyte polyclonal mitogens. PLE shows a significant inhibitory effect on the proliferative response of PBMNC to stimulation with phytohaemagglutinin (PHA) or anti CD3 monoclonal antibodies (p < 0.05). In contrast, PLE did not modify the proliferative response of PBMNC to phorbol esters (p > 0.05). The inhibitory effect of PLE upon mitogen induced PBMNC proliferation is time dependent and can be overcome by the exogenous addition of interleukin-2 to the culture medium (p < 0.05). The decreased proliferative response of PBMNC to PHA stimulation in the presence of PLE is not associated with a significant modification of expression of the alpha chain (CD25) of the IL-2 receptor (p > 0.05). In conclusion, PLE shows an inhibitory effect on the polyclonal proliferative response of PBMNC to T lymphocyte mitogens that interact with cytoplasmic membrane molecules.

Sepsis-induced acute respiratory distress syndrome with fatal outcome is associated to increased serum transforming growth factor beta-1 levels☆

BACKGROUND TGF-β1 is a promoter of pulmonary fibrosis in many chronic inflammatory diseases. TGF-β1 circulating levels in patients with sepsis-induced Acute Respiratory Distress Syndrome (ARDS) have not been established. METHODS In this prospective pilot cohort study, serum bioactive TGF-β1 concentration, determined by sandwich ELISA, was analyzed in 52 patients who fulfilled criteria for septic shock at admission and on days 3 and 7. RESULTS Of the 52 patients enrolled in the study, 46.1% fulfilled the criteria for ARDS on admission. At ICU admission, there were not statistical differences in TGF-β1 concentrations between septic shock patients with or without ARDS. After 7 days of follow-up in ICU, circulating TGF-β1 levels were significantly higher in patients with sepsis and ARDS than in those without ARDS [55.47 (35.04-79.48 pg/ml) versus 31.65 (22.89-45.63 pg/ml), respectively] (p = 0.002). Furthermore, in septic shock associated ARDS patients, TGF-β1 levels were significantly higher in nonsurvivors than in survivors [85.23 (78.19-96.30 pg/ml) versus 36.41 (30.21-55.47 pg/ml), respectively] (p = 0.006) on day 7 of ICU follow-up. CONCLUSIONS In patients with septic shock, persistent ARDS is accompanied with increased circulating TGF-β1 levels. Furthermore, ARDS patients with fatal outcome show higher TGF-β1 concentrations than survivors. These results suggest the relevance of TGF-β1 levels found in the pathogenesis of persistent sepsis-induced ARDS.

Diminished T lymphocyte proliferative response to polyclonal mitogens in acute brucellosis patients

SummaryT lymphocytes from 21 untreated patients with acute brucellosis were tested for their proliferative response to polyclonal mitogens. The purified T lymphocytes from these patients showed a defective proliferative response to plant lectins and anti CD3 monoclonal antibodies with respect to the response observed in T lymphocytes from 21 healthy controls (p<0.05). This defective proliferative response was not corrected by the exogenous addition of interleukin-2 or tumor necrosis factors alpha or beta to the culture medium. After antibiotic therapy, the proliferative response to the mitogens in T lymphocytes was found to be similar to that of the healthy controls (p>0.05), and significantly higher than that found before treatment (p<0.05). It was concluded that T lymphocytes from acute brucellosis patients have a defective proliferative response to membrane mitogenic signals, which disappears when the patients are cured after antibiotic treatment.ZusammenfassungT-Lymphozyten von 21 unbehandelten Patienten mit akuter Bruzellose wurden auf ihre Proliferations-antwort auf polyklonale Mitogene untersucht. Auf Pflanzenlektine und anti-CD3-monoklonale Antikörper reagierten die gereinigten T-Lymphozyten dieser Patienten mit einer im Vergleich zu T-Lymphozyten von 21 gesunden Kontrollpersonen verminderten Proliferations-Antwort (p<0,05). Dieser Defekt konnte durch die exogene Gabe von Interleukin-2 und Tumornekrosefaktor alpha oder beta zum Kulturmedium nicht ausgeglichen werden. Nach Antibiotikatherapie näherte sich die T-Lymphozyten-Proliferationsantwort der Patienten an die der gesunden Kontrollpersonen (p>0,05) an; sie war gegenüber der Phase vor Therapie signifikant gesteigert (p<0,05). Aus diesen Befunden ist auf einen Defekt in der Proliferationsantwort der T-Lymphozyten auf mitogene Membransignale zu schließen, der verschwindet, wenn die Patienten nach Antibiotikatherapie geheilt sind.T lymphocytes from 21 untreated patients with acute brucellosis were tested for their proliferative response to polyclonal mitogens. The purified T lymphocytes from these patients showed a defective proliferative response to plant lectins and anti CD3 monoclonal antibodies with respect to the response observed in T lymphocytes from 21 healthy controls (p<0.05). This defective proliferative response was not corrected by the exogenous addition of interleukin-2 or tumor necrosis factors alpha or beta to the culture medium. After antibiotic therapy, the proliferative response to the mitogens in T lymphocytes was found to be similar to that of the healthy controls (p>0.05), and significantly higher than that found before treatment (p<0.05). It was concluded that T lymphocytes from acute brucellosis patients have a defective proliferative response to membrane mitogenic signals, which disappears when the patients are cured after antibiotic treatment. T-Lymphozyten von 21 unbehandelten Patienten mit akuter Bruzellose wurden auf ihre Proliferations-antwort auf polyklonale Mitogene untersucht. Auf Pflanzenlektine und anti-CD3-monoklonale Antikörper reagierten die gereinigten T-Lymphozyten dieser Patienten mit einer im Vergleich zu T-Lymphozyten von 21 gesunden Kontrollpersonen verminderten Proliferations-Antwort (p<0,05). Dieser Defekt konnte durch die exogene Gabe von Interleukin-2 und Tumornekrosefaktor alpha oder beta zum Kulturmedium nicht ausgeglichen werden. Nach Antibiotikatherapie näherte sich die T-Lymphozyten-Proliferationsantwort der Patienten an die der gesunden Kontrollpersonen (p>0,05) an; sie war gegenüber der Phase vor Therapie signifikant gesteigert (p<0,05). Aus diesen Befunden ist auf einen Defekt in der Proliferationsantwort der T-Lymphozyten auf mitogene Membransignale zu schließen, der verschwindet, wenn die Patienten nach Antibiotikatherapie geheilt sind.