Impaired cytokine production by neutrophils isolated from patients with AIDS

Systemic and mucosal mobilization of granulocyte subsets during lentiviral infection

Granulocytes mediate broad immunoprotection through phagocytosis, extracellular traps, release of cytotoxic granules, antibody effector functions and recruitment of other immune cells against pathogens. However, descriptions of granulocytes in HIV infection and mucosal tissues are limited. Our goal was to characterize granulocyte subsets in systemic, mucosal and lymphoid tissues during lentiviral infection using the rhesus macaque (RM) model. Mononuclear cells from jejunum, colon, cervix, vagina, lymph nodes, spleen, liver and whole blood from experimentally naïve and chronically SHIVsf162p3-infected RM were analysed by microscopy and polychromatic flow cytometry. Granulocytes were identified using phenotypes designed specifically for RM: eosinophils-CD45+  CD66+  CD49d+ ; neutrophils-CD45+  CD66+  CD14+ ; and basophils-CD45+  CD123+  FcRε+ . Nuclear visualization with DAPI staining and surface marker images by ImageStream (cytometry/microscopy) further confirmed granulocytic phenotypes. Flow cytometric data showed that all RM granulocytes expressed CD32 (FcRγII) but did not express CD16 (FcRγIII). Additionally, constitutive expression of CD64 (FcRγI) on neutrophils and FcRε on basophils indicates the differential expression of Fc receptors on granulocyte subsets. Granulocytic subsets in naïve whole blood ranged from 25·4% to 81·5% neutrophils, 0·59% to 13·3% eosinophils and 0·059% to 1·8% basophils. Interestingly, elevated frequencies of circulating neutrophils, colorectal neutrophils and colorectal eosinophils were all observed in chronic lentiviral disease. Conversely, circulating basophils, jejunal eosinophils, vaginal neutrophils and vaginal eosinophils of SHIVsf162p3-infected RM declined in frequency. Overall, our data suggest modulation of granulocytes in chronic lentiviral infection, most notably in the gastrointestinal mucosae where a significant inflammation and disruption occurs in lentivirus-induced disease. Furthermore, granulocytes may migrate to inflamed tissues during infection and could serve as targets of immunotherapeutic intervention.

Interactions of HIV and Antiretroviral Therapy With Neutrophils and Platelets

Neutrophils are important components of the innate immune system that mediate pathogen defense by multiple processes including phagocytosis, release of proteolytic enzymes, production of reactive oxygen species, and neutrophil extracellular trap formation. Abnormalities of neutrophil count and function have been described in the setting of HIV infection, with the majority of antiretroviral agents (ARVs), excluding zidovudine, having been reported to correct neutropenia. Questions still remain, however, about their impact on neutrophil function, particularly the possibility of persistent neutrophil activation, which could predispose people living with HIV to chronic inflammatory disorders, even in the presence of virally-suppressive treatment. In this context, the effects of protease inhibitors and integrase strand transfer inhibitors, in particular, on neutrophil function remain poorly understood and deserve further study. Besides mediating hemostatic functions, platelets are increasingly recognized as critical role players in the immune response against infection. In the setting of HIV, these cells have been found to harbor the virus, even in the presence of antiretroviral therapy (ART) potentially promoting viral dissemination. While HIV-infected individuals often present with thrombocytopenia, they have also been reported to have increased platelet activation, as measured by an upregulation of expression of CD62P (P-selectin), CD40 ligand, glycoprotein IV, and RANTES. Despite ART-mediated viral suppression, HIV-infected individuals reportedly have sustained platelet activation and dysfunction. This, in turn, contributes to persistent immune activation and an inflammatory vascular environment, seemingly involving neutrophil-platelet-endothelium interactions that increase the risk for development of comorbidities such as cardiovascular disease (CVD) that has become the leading cause of morbidity and mortality in HIV-infected individuals on treatment, clearly underscoring the importance of unraveling the possible etiologic roles of ARVs. In this context, abacavir and ritonavir-boosted lopinavir and darunavir have all been linked to an increased risk of CVD. This narrative review is therefore focused primarily on the role of neutrophils and platelets in HIV transmission and disease, as well as on the effect of HIV and the most common ARVs on the numbers and functions of these cells, including neutrophil-platelet-endothelial interactions.

Anti-inflammatory effect of traditional Chinese medicine preparation Penyanling on pelvic inflammatory disease

ETHNOPHARMACOLOGICAL RELEVANCE

Penyanling is made up of Smilacis Glabrae Rhizoma (SG, from Smilar glabra Roxb.), Angelicae Sinensis Radix (AS, from Angelica sinensis (Oliv.) Diels), Salviae Miltiorrhizae Radix et Rhizoma (SM, from Salvia miltiorrhiza Bunge), Sargentodoxae Caulis (SC, from Sargentodoxa cuneata (Oliv.) Rehd.et Wils.), Linderae Radix (LR, from Lindera aggregata (Sims) Kosterm.), Paeoniae Radix Rubra (PR, from Paeonia lactiflora Pall.), Sparganii Rhizoma (SR, from Sparganium stoloniferum (Graebn.) Buch.-Ham.), Corydalis Rhizoma (CoR, from Corydalis yanhusuo W. T. Wang), Cyperi Rhizoma (CyR, from Cyperus rotundus Linn.), Glycyrrhizae Radix et Rhizoma (GR, from Glycyrrhiza uralensis Fisch.), and Patrinia Scabiosaefolia (PS, from Patrinia scabiosaefolia Fisch. ex Trev.) recorded in Chinese Pharmacopoeia. It has been used on pelvic inflammatory disease (PID) for more than twenty years.

AIM OF THE STUDY

This study was carried out to illustrate its pharmacological action and clarify its substantial composition.

MATERIALS AND METHODS

The anti-inflammatory effects of Penyanling were studied on a PID rat model and a lipopolysaccharides (LPS)-stimulated THP-1 cell line. Histological changes and levels of inflammatory factors in the uterine tube of the PID rat were examined. Levels of nuclear factor-kappa B (NF-κB) in the nuclear of THP-1 cells and NF-κB, IκB-α, and FPR2 in the cytoplasm were tested by Western blot analysis. Substances within Penyanling were scanned with liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-Q-TOF-MS). The contents of total flavonoids, phenolics, and saponins were quantified.

RESULTS

The anti-inflammatory effects of Penyanling were observed on PID rats, such as suppressing the infiltrations of lymphocytes and neutrophils in the uterine tube, decreasing the release of interleukin (IL)-1β, IL-6, IL-8, and monocyte chemotactic protein (MCP)-1, and promoting the production of lipoxin A₄ (LXA₄). On the other hand, Penyanling regulated the activity of NF-κB signal pathway on the LPS-stimulated THP-1 cell line, which suggested the potential mechanism of its anti-inflammatory effect. Besides, it could promote the expression of formyl peptide receptor 2 (FPR2), which suggested its effect on enhancing the resolution of inflammation. Seventy-six substances were identified by their accurate molecular weights, mass fragment patterns, retention times, and standards if available. Most of these substances were flavonoids, phenolics, saponins, and alkaloids. The contents of total flavonoids, phenolics, and saponins within Penyanling were 0.186, 1.371, and 4.321 mg/mL, respectively.

CONCLUSION

Penyanling showed an anti-inflammatory effect on PID, and its potential mechanism involved suppressing NF-κB signal pathway and promoting the resolution of inflammation. The main substances within it were flavonoids, phenolics, saponins, and alkaloids.

Comparison of the Analgesic and Anti-Inflammatory Effects of Xiaoyuningkun Decoction with Cynanchum Paniculatum and Fukeqianjin in a Mouse Model of Pelvic Inflammatory Disease

BACKGROUND Preclinical and clinical studies have shown that the extract of Cynanchum paniculatum (bunge) kitag and the fukeqianjin formulation have beneficial effects in pelvic inflammatory disease (PID). This study aimed to compare the effects of Cynanchum paniculatum and fukeqianjin with a new decoction, xiaoyuningkun, consisting of Melia toosendan, Angelica biserrata, and Cynanchum paniculatum, in a mouse model of PID. MATERIAL AND METHODS The mouse model of PID included injection of the upper genital tract with hydrochloric acid (HCl) and lipopolysaccharide (LPS). The control group underwent sham treatment with 0.9% physiological saline. Cynanchum paniculatum, fukeqianjin, and xiaoyuningkun decoction were administered orally for 15 days. Acetic acid-induced writhing and thermal nociception hot plate tests evaluated the analgesic effects of treatment. Mouse uterus and Fallopian tubes were examined histologically to evaluate the degree of inflammation. Immunohistochemistry was used to measure the protein expression of intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial growth factor (VEGF). Enzyme-linked immunosorbent assay (ELISA) measured serum levels of inflammatory cytokines. RESULTS Treatment with xiaoyuningkun decoction significantly reduced the pain threshold in the mouse model of PID and the degree of inflammation in the uterus and Fallopian tubes compared with Cynanchum paniculatum and fukeqianjin. Cynanchum paniculatum decoction significantly reduced the serum levels of interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-alpha), ICAM-1, and VEGF, and the expression of ICAM-1 and VEGF in the mouse uterus and Fallopian tubes. CONCLUSIONS The new xiaoyuningkun decoction had analgesic and anti-inflammatory effects in the mouse model of PID, possibly by inhibiting ICAM-1, VEGF, and inflammatory cytokines.

Neutrophil Vaccination Dynamics and Their Capacity To Mediate B Cell Help in Rhesus Macaques

Neutrophils are the most abundant leukocyte and play a critical role in the initial response to an Ag. Recently, their ability to contribute to adaptive immunity has been highlighted. We evaluated the ability of neutrophils from blood to contribute to the adaptive immune response in a preclinical rhesus macaque SIV vaccine trial. Replication-competent adenovirus-SIV recombinants induced neutrophil activation, B cell help markers, and enhanced ability to generate reactive oxygen species. Boosting with SIV vaccines (adjuvant together with ALVAC or DNA plus envelope protein) elicited significant neutrophil responses. Serum cytokine and chemokine levels induced correlated with the frequency of neutrophil subsets expressing IL-21, myeloperoxidase, and CD64. Post-SIV infection, neutrophils exhibited dysfunction, both phenotypically and functionally. B cells from protected and infected macaques cocultured with autologous polymorphonuclear cells, consisting primarily of neutrophils, were activated, underwent class switching, and produced Abs. This B cell help was not aided by addition of IL-10 and was largely contact dependent. Numerous genes associated with inflammation, Ab production, and chemotaxis were upregulated in the cocultured B cells. We conclude that immune stimulation by vaccination or antigenic exposure imparts a greater ability of neutrophils to contribute to the adaptive immune response. Harnessing this granulocytic response has the potential to improve vaccine efficacy.

Anti-Inflammatory Effect of Feiyangchangweiyan Capsule on Rat Pelvic Inflammatory Disease through JNK/NF-κB Pathway

Objectives

In this study, we aimed to illustrate the preventive effect and possible mechanisms of Feiyangchangweiyan capsule (FYCWYC) on rat pelvic inflammatory disease (PID) model.

Methods

To construct the rat PID model, upper genital tract was infected by multipathogen, and then drugs were orally administered for 8 days. The histological examination, immunohistochemical analysis, and ELISA were carried out. Furthermore, Western blotting was used to analyze the expression of Akt, MAPKs, NF-κB p65, and IκB-α in uterus.

Results

As the results showed, infiltrations of neutrophils and lymphocytes in uterus were significantly suppressed, and IL-1β, IL-6, CXCL-1, and TNF-α were also reduced in a dose-dependent manner. We also found that FYCWYC inhibited apoptosis induced by infection. Furthermore, FYCWYC could block the infection-induced nuclear translocation of NF-κB. We found that FYCWYC treatment only decreased the phosphorylation of JNK induced by infection and had no effects on Akt and P38. Additional, the effects of SP600125, an inhibitor of phospho-JNK, were similar to the results of FYCWYC.

Conclusions

Taken together, our results demonstrated that FYCWYC had anti-inflammatory effect in pathogen-induced PID model, and the mechanism might be through inhibiting NF-κB nuclear translocation which is mediated by JNK.

Rhizoma Smilacis Glabrae inhibits pathogen-induced upper genital tract inflammation in rats through suppression of NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Smilacis Glabrae (RSG) is traditionally used to treat gynecological disease, which is simply recorded in Chinese Pharmacopoeia. However, whether it has effect on upper genital tract inflammation (UGTI) is unclear.

AIM OF THE STUDY

To evaluate the pharmacological effect of RSG on UGTI in rats and analyze its phytochemistry characteristics.

MATERIALS AND METHODS

The substances in RSG extract was qualified by LC-Q-TOF-MS method, and 11 substances were further quantified. The RSG extract, at dose of 241, 482 (clinical dose) and 964mg/kg/day, was orally administered to UGTI rats whose upper genital tracts were multi-infected with pathogens. Infiltrations of neutrophil and lymphocyte and productions of IL-1β, IL-6, CXCL-1, MCP-1, RANTES, PGE2, COX-2, NF-κB p65 and IκB-α in upper genital tract were examined to evaluate the effects of RSG and its potential mechanism.

RESULTS

A total of 77 substances were detected in RSG extract, with 50 substances putatively identified, most of which were flavonoids, phenolic acids and phenylpropanoids. The quantification analysis showed flavonoid had a relative high amount. In pharmacological study, RSG extract suppressed infiltrations of inflammatory cells, reduced over-productions of factors involved in inflammation and pelvic pain. A potential mechanism of these effects was blocking NF-κB signal pathway.

CONCLUSIONS

The RSG extract exhibited anti-inflammatory effect on UGTI, with a potential mechanism of blocking the activation of NF-κB signal pathway. The effect may be involved in the presence of substances, such as flavonoids and phenolic acids.

The anti-inflammatory effect of Andrographis paniculata (Burm. f.) Nees on pelvic inflammatory disease in rats through down-regulation of the NF-κB pathway

BACKGROUND

Andrographis paniculata (Burm. f.) Nees (APN), a principal constituent of a famous traditional Chinese medicine Fukeqianjin tablet which is used for the treatment of pelvic inflammatory disease (PID), has been reported to have anti-inflammatory effect in vitro. However, whether it has pharmacological effect on PID in vivo is unclear. Therefore, the aim of this study is to test the anti-inflammatory effect of APN and illuminate a potential mechanism.

METHODS

Thirty-six female specific pathogen-free SD rats were randomly divided into control group, PID group, APN1 group, APN2 group, APN3 group and prednisone group. Pathogen-induced PID rats were constructed. The APN1, APN2 and APN3 group rats were orally administrated with APN extract at different levels. The prednisone group rats were administrated with prednisone. Eight days after the first infection, the histological examination of upper genital tract was carried out, and enzyme-linked immunosorbent assay (ELISA) was carried out using homogenate of the uterus and fallopian tube. Furthermore, immunohistochemical evaluations of NF-κB p65 and IκB-α in uterus was conducted.

RESULTS

APN obviously suppressed the infiltrations of neutrophils and lymphocytes, and it could significantly reduce the excessive production of cytokines and chemokines including IL-1β, IL-6, CXCL-1, MCP-1 and RANTES in a dose-dependent manner. Furthermore, APN could block the pathogen-induced activation of NF-κB pathway.

CONCLUSION

APN showed potent anti-inflammatory effect on pathogen-induced PID in rats, with a potential mechanism of inhibiting the NF-κB signal pathway.

Immune activation in the course of HIV-1 infection: Causes, phenotypes and persistence under therapy

Systemic immune activation is a striking consequence of HIV-1 infection. Even in virologically suppressed patients, some hyperactivity of the immune system and even of the endothelium and of the coagulation pathway may persist. Apart from immune deficiency, this chronic activation may contribute to various morbidities including atherothrombosis, neurocognitive disorders, liver steatosis and osteoporosis, which are currently main challenges. It is therefore of major importance to better understand the causes and the phenotypes of immune activation in the course of HIV-1 infection. In this review we will discuss the various causes of immune activation in HIV-1 infected organisms: the presence of the virus together with other microbes, eventually coming from the gut, CD4+ T cell lymphopenia, senescence and dysregulation of the immune system, and/or genetic factors. We will also describe the activation of the immune system: CD4+ and CD8+ T cells, B cells, NKT and NK cells, dendritic cells, monocytes and macrophages, and neutrophils of the inflammation cascade, as well as of the endothelium and the coagulation system. Finally, we will see that antiretroviral therapy reduces the hyperactivity of the immune and coagulation systems and the endothelial dysfunction, but often does not abolish it. A better knowledge of this phenomenon might help us to identify biomarkers predictive of non AIDS-linked comorbidities, and to define new strategies aiming at preventing their emergence.

Cocaine alters cytokine profiles in HIV-1-infected African American individuals in the DrexelMed HIV/AIDS genetic analysis cohort

BACKGROUND

This study evaluated the relationship between illicit drug use and HIV-1 disease severity in HIV-1-infected patients enrolled in the DREXELMED HIV/AIDS Genetic Analysis Cohort. Because cocaine is known to have immunomodulatory effects, the cytokine profiles of preferential nonusers, cocaine users, and multidrug users were analyzed to understand the effects of cocaine on cytokine modulation and HIV-1 disease severity.

METHODS

Patients within the cohort were assessed approximately every 6 months for HIV-1 clinical markers and for history of illicit drug, alcohol, and tobacco use. The Luminex human cytokine 30-plex panel was used for cytokine quantitation. Analysis was performed using a newly developed biostatistical model.

RESULTS

Substance abuse was common within the cohort. Using the drug screens at the time of each visit, the subjects in the cohort were categorized as preferential nonusers, cocaine users, or multidrug users. The overall health of the nonuser population was better than that of the cocaine users, with peak and current viral loads in nonusers substantially lower than those in cocaine and multidrug users. Among the 30 cytokines investigated, differential levels were established within the 3 populations. The T-helper 2 cytokines, interleukin-4 and -10, known to play a critical role during HIV-1 infection, were positively associated with increasing cocaine use. Clinical parameters such as latest viral load, CD4 T-cell counts, and CD4:CD8 ratio were also significantly associated with cocaine use, depending on the statistical model used.

CONCLUSIONS

Based on these assessments, cocaine use seems to be associated with more severe HIV-1 disease.

Interactions between human immunodeficiency virus type 1 and polymorphonuclear neutrophils

Polymorphonuclear neutrophils (PMN) are the most abundant circulating leukocytes. They represent a first line of innate immunity against a large panel of microbial pathogens, pending development of specific immune responses. The role of PMN in human immunodeficiency virus type 1 (HIV-1) disease has mainly been investigated from the point of view of the increased susceptibility of HIV-1-infected patients to bacterial and fungal infections. However, it is now clear that the relationship between PMN and HIV-1 is far more complex. This review examines both the beneficial and the detrimental effects of PMN during HIV infection.

IL-23 and IL-12p70 production by monocytes and dendritic cells in primary HIV-1 infection

IL-12 enhances protective responses against HIV replication. Its production after in vitro stimulation is defective in chronic HIV infection, but higher responses can be found. IL-23 shares the p40 chain and some properties with IL-12 and enhances Th17 responses, but its role in HIV infection is unknown. The production of IL-12 and IL-23 and the respective contribution of monocytes and myeloid conventional DC (cDCs) during primary HIV infection were determined. Sixteen patients included in the French PRIMO-ANRS Cohort without antiretroviral treatment were followed prospectively and compared with uninfected donors. Intracellular p40 expression by monocytes and cDCs, analyzed by flow cytometry, was transiently increased in monocytes and cDCs in response to LPS and more consistently, in monocytes in response to LPS + IFN-gamma. IL-23 production, measured by ELISA after PBMC stimulation, was induced by LPS in strong correlation with VLs. IL-12p70 production required the addition of IFN-gamma and was transiently increased in patients compared with controls in correlation with VLs, whereas IL-23 was increased sustainedly. Therefore, an apparent domination of IL-23 over IL-12 responses occurred throughout primary HIV infection, and a potential restoration of IL-12 responses might be expected from a treatment mimicking activated T cell signals.

Community-associated methicillin-resistant Staphylococcus aureus in the patient with HIV infection

The prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has increased alarmingly in both the general population and the HIV-infected community. We look at the background of MRSA including the mechanisms of resistance, genetics, and trends in the individual with HIV infection. Numerous studies have investigated the risk factors for CA-MRSA. Other studies have further characterized the incidence of and risk factors for MRSA infections in the HIV community. Although one might not readily associate advanced HIV infection with increased susceptibility to bacterial pathogens, a number of studies have explained the mechanisms of this B-cell-mediated susceptibility. Invasive MRSA infections have spread into communities, are increasingly prevalent, and pose a public health challenge for their containment, prevention, and treatment.

Regulation of interleukin 12 p40 and p70 production by blood and alveolar phagocytes during severe sepsis

Paradoxically, the host response to severe sepsis may lead to immunosuppression, thereby favoring nosocomial infections. We examined the role of the two IL-12 isoforms, bioactive IL-12p70 and regulatory IL-12p40, in 16 patients with severe sepsis. We compared the capacity of purified blood and alveolar phagocytes [polymorphonuclear neutrophils (PMN) and monocytes/macrophages] to secrete each isoform. Blood monocytes had normal basal secretions. In contrast, a marked imbalance was observed after ex vivo stimulation by lipopolysaccharide plus IFN-gamma, with significantly lower IL-12p70 production and higher IL-12p40 production. Conversely, stimulated IL-12p40 production by the patients' blood PMN tended to be impaired, as was their cell-surface beta2 integrin and L-selectin expression, known as markers of cell activation. In the patient's bronchoalveolar lavage fluid, the production of both IL-12 isoforms after ex vivo stimulation was significantly lower with alveolar macrophages than with autologous blood monocytes and significantly higher with alveolar PMN than with autologous blood PMN. This sheds new light on the potential role of PMN in local modulation of inflammation, via secretion of the anti-inflammatory IL-12 p40 subunit. The imbalance between the bioactive and regulatory IL-12 isoforms, which is probably designed to control excessive inflammation, may also make septic patients more susceptible to nosocomial infection.

Detection of elevated serum beta-chemokine levels in seronegative Chinese individuals exposed to human immunodeficiency virus type 1

The mutations in the CCR5 coding region, such as CCR5Delta32 and CCR5m303, that suppress the transmission of human immunodeficiency virus (HIV) type 1 do not exist in Chinese people. However, 9 Chinese subjects in Taiwan with histories of multiple sexual exposures to HIV remained uninfected, suggesting that certain anti-HIV factors do indeed exist. Experiments were therefore designed to investigate the immune mechanism that protects this cohort against HIV infection. Peripheral blood samples from these 9 subjects and 7 healthy people who had not been exposed to HIV were obtained for the quantitation of the levels for beta-chemokines and interleukin 16 (IL-16) in serum samples or secreted by peripheral blood lymphocytes. Significantly higher serum levels for nearly all 3 beta-chemokines, regulation on activation, normal T cell-expressed and secreted, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta (P<.05, P<.05, and P=.05, respectively), but not IL-16, were detected in the 9 HIV-uninfected subjects as compared with control subjects. The result suggests that among the host genes and cellular factors thus far identified, beta-chemokines are the major HIV-suppressive factors that protect Chinese people from infection with HIV.

Influence of HIV infection on presentation of Kaposi's sarcoma

We report a retrospective review of 57 patients with endemic Kaposi's sarcoma (EKS) seen between 1981 and 1990 and 40 prospectively diagnosed patients with and without human immunodeficiency virus (HIV) infection seen between 1991 and 1995. In the retrospective study 52 patients were males and five were females. Their ages ranged between 15 and 62 years with a mean of 39 years.Thirty-five (61%) patients had symptoms for more than 1 year. Nodular KS was seen in 75% of the patients. In the prospective study 26 patients had EKS while 14 had AIDS associated KS (AAKS). Among the patients with EKS 24 were males and two were females. The mean duration of symptoms was 20 months. The CD4 count done on nine patients ranged between 900 and 1300 cells/mm3 and there was no mortality within 1 year of presentation. Eleven of the patients with AAKS were males and three were females. Their ages ranged between 22 months and 41 years with a mean of 26. Nine patients had symptoms for less than 6 months. Ten patients had peripheral lymphadenopathy. CD4 counts done on 11 patients ranged between 200 and 800 cells/mm3. Five patients (35%) died within 6 months of presentation. Between 1991 and 1995, 486 patients were seen with HIV infection. Patients with AAKS present with fulminant disease which seemed quickly fatal.

Interleukin-1 receptor antagonist production during infectious and noninfectious systemic inflammatory response syndrome

OBJECTIVE

To analyze the levels of circulating and cell-associated forms of interleukin-1 receptor antagonist (IL-1ra) and the spontaneous and the lipopolysaccharide- or streptococcus-induced ex vivo production of IL-1ra by isolated neutrophils.

DESIGN

Cohort study.

SETTING

A collaborative study between an intensive care unit and a research laboratory.

PATIENTS

Septic patients (those with infectious systemic inflammatory response syndrome [SIRS]) and patients undergoing cardiac surgery with cardiopulmonary bypass (noninfectious SIRS).

MEASUREMENTS AND MAIN RESULTS

Both noninfectious and infectious SIRS patients had enhanced levels of plasma IL-1ra. In septic patients, the increased level of IL-1ra associated with circulating leukocytes reflected the higher number of circulating neutrophils, because these cells, as well as peripheral blood mononuclear cells, contained similar levels of cell-associated forms of IL-1ra than those found at homeostasis in healthy controls. The analysis of the in vitro production of IL-1ra by neutrophils showed a decreased capacity of these cells to release the secreted form of IL-1ra on activation in all patients when compared with that capacity in healthy controls. In contrast, the production of the intracellular forms of IL-1ra was not altered in septic patients, but it was diminished in post-cardiopulmonary bypass patients.

CONCLUSIONS

The capacity of releasing IL-1ra by activated neutrophils from infectious or noninfectious SIRS patients was diminished. In contrast, the accumulation of intracellular IL-1ra in septic patients was not modified when compared with that in healthy controls. These ex vivo data illustrate that a different gene regulation of the secreted and intracellular forms of IL-1 ra occurs during a pathologic situation like sepsis.

Differential production of IFN-gamma, analyzed at the single-cell level, by specific subsets of human NK and T cells from healthy and HIV(+) subjects

BACKGROUND

Interferon gamma is a cytokine that plays a central role in immunity, and is physiologically secreted by T and NK cells under appropriate stimuli during the immune response. By means of flow cytometry, we performed a single cell analysis of interferon gamma producing NK cells and their surface phenotype in normal and HIV(+) individuals that show several defects of cytokine production and cellular immunity.

METHODS

PBMC or purified NK cells were stimulated for 1-12 h with PMA/ionomycin in the presence of monensin, subsequently stained for surface CD56 and CD3 or CD8, and for intracytoplasmic IFN-gamma, and analysed by flow cytometry.

RESULTS

Our results show that CD56(+) NK cells are more efficient interferon gamma producers than T cells. Moreover, within the CD56(+) NK cell population, those that co-express low density CD8 are the best producers. Finally, we show that NK cells during HIV infection are more massively recruited to interferon gamma production than those from normal subjects.

CONCLUSIONS

Both in the normal and HIV(+) subjects, a higher percentage of NK cells than T cells can produce IFN-gamma although differences can be identified within the NK cells subset in terms of IFN-gamma production. The production of IFN-gamma is fully achievable in the HIV(+) subjects, which is consistent with their elevated plasmatic levels of the cytokine. The possibility that NK cells that produce interferon gamma could represent a functionally distinct population committed to the production of this cytokine, is discussed.

Respiratory Syncytial Virus Stimulates Neutrophil Degranulation and Chemokine Release

Neutrophil infiltration of the airways is a common finding in respiratory syncytial virus (RSV) bronchiolitis. Neutrophil-derived chemokines and neutrophil granule contents can cause further inflammation, hyperresponsiveness, and damage of the airways. In this study, peripheral blood neutrophils incubated with RSV (multiplicity of infection (MOI) = 10) induced IL-8, macrophage inflammatory protein (MIP)-1α, MIP-1β, and myeloperoxidase (MPO) release. In contrast, LPS induced only chemokine but not MPO release. RSV-induced chemokine and MPO release was noncytotoxic as assessed by trypan blue exclusion. The mechanism of RSV-induced chemokine release was shown to be transcription dependent since cytokine mRNA synthesis was increased with RSV stimulation and the process was inhibited by actinomycin-D. In addition, the effect of dexamethasone (dex) on mediator release was also studied. Dex significantly inhibited chemokine release but did not inhibit MPO release. The mechanism of inhibition of the release of these chemokines is probably posttranscriptional since the mRNA synthesis was not inhibited by dex. We conclude that the release of chemokines (IL-8, MIP-1α, MIP-1β) and granule enzymes (MPO) by RSV-stimulated neutrophils may contribute to the pulmonary pathology in RSV bronchiolitis. These in vitro findings showing that dex failed to consistently inhibit all the RSV-induced release of neutrophil inflammatory mediators may explain the variable efficacy of corticosteroids in the treatment of RSV bronchiolitis.