Endogenous Interleukin 4 Is Required for Development of Protective CD4+ T Helper Type 1 Cell Responses to Candida albicans

Interleukin (IL)-4–deficient mice were used to assess susceptibility to systemic or gastrointestinal Candida albicans infections, as well as parameters of innate and elicited T helper immunity. In the early stage of systemic infection with virulent C. albicans, an unopposed interferon (IFN)-γ response renders IL-4–deficient mice more resistant than wild-type mice to infection. Yet, IL-4–deficient mice failed to efficiently control infection in the late stage and succumbed to it. Defective IFN-γ and IL-12 production, but not IL-12 responsiveness, was observed in IL-4–deficient mice that failed to mount protective T helper type 1 cell (Th1)-mediated acquired immunity in response to a live vaccine strain of the yeast or upon mucosal immunization in vivo. In vitro, IL-4 primed neutrophils for cytokine release, including IL-12. However, late treatment with exogenous IL-4, while improving the outcome of infection, potentiated CD4⁺ Th1 responses even in the absence of neutrophils. These findings indicate that endogenous IL-4 is required for the induction of CD4⁺ Th1 protective antifungal responses, possibly through the combined activity on cells of the innate and adaptive immune systems.     

Incompetence of Neutrophils to Invasive Group A streptococcus Is Attributed to Induction of Plural Virulence Factors by Dysfunction of a Regulator

Group A streptococcus (GAS) causes variety of diseases ranging from common pharyngitis to life-threatening severe invasive diseases, including necrotizing fasciitis and streptococcal toxic shock-like syndrome. The characteristic of invasive GAS infections has been thought to attribute to genetic changes in bacteria, however, no clear evidence has shown due to lack of an intriguingly study using serotype-matched isolates from clinical severe invasive GAS infections. In addition, rare outbreaks of invasive infections and their distinctive pathology in which infectious foci without neutrophil infiltration hypothesized us invasive GAS could evade host defense, especially neutrophil functions. Herein we report that a panel of serotype-matched GAS, which were clinically isolated from severe invasive but not from non-invaive infections, could abrogate functions of human polymorphnuclear neutrophils (PMN) in at least two independent ways; due to inducing necrosis to PMN by enhanced production of a pore-forming toxin streptolysin O (SLO) and due to impairment of PMN migration via digesting interleukin-8, a PMN attracting chemokine, by increased production of a serine protease ScpC. Expression of genes was upregulated by a loss of repressive function with the mutation of csrS gene in the all emm49 severe invasive GAS isolates. The csrS mutants from clinical severe invasive GAS isolates exhibited high mortality and disseminated infection with paucity of neutrophils, a characteristic pathology seen in human invasive GAS infection, in a mouse model. However, GAS which lack either SLO or ScpC exhibit much less mortality than the csrS-mutated parent invasive GAS isolate to the infected mice. These results suggest that the abilities of GAS to abrogate PMN functions can determine the onset and severity of invasive GAS infection.     

Serum levels of inhibitory costimulatory molecules and correlations with levels of innate immune cytokines in patients with pulmonary tuberculosis

ObjectiveTo analyze serum levels of inhibitory costimulatory molecules and their correlations with innate immune cytokine levels in patients with pulmonary tuberculosis (PTB).MethodsData for 280 PTB patients and 280 healthy individuals were collected. Serum levels of immune molecules were measured using ELISA. Univariate, multivariate, subgroup, matrix correlation, and receiver operating characteristic curve analyses were performed.ResultsHost, environment, lifestyle, clinical features, and medical history all influenced PTB. Serum levels of soluble programmed death ligand 1 (sPD-L1), soluble T-cell immunoglobulin- and mucin-domain–containing molecule 3 (sTim-3), soluble galectin-9 (sGal-9), interleukin (IL)-4, and IL-33 were significantly higher in patients with PTB, while levels of IL-12, IL-23, IL-18, and interferon (IFN)-γ were significantly lower. Serum levels of sTim-3 were higher in alcohol users. Levels of sTim-3 were negatively correlated with those of IL-12. Levels of IL-12, IL-23, and IL-18 were positively correlated with those of IFN-γ, while levels of IL-12 were negatively correlated with those of IL-4. The areas under the curve of sPD-L1, sTim-3, sGal-9, IL-12, IL-23, IL-18, IFN-γ, IL-4, and IL-33 for identifying PTB were all >0.77.ConclusionsInhibitory costimulatory molecules may be targets for controlling PTB. Immune molecules may be helpful for diagnosis of PTB.     

Selective Expression of an Interleukin-12 Receptor Component by Human T Helper 1 Cells

Interleukin-12 (IL-12), a heterodimeric cytokine produced by activated monocytes and dendritic cells, plays a crucial role in regulating interferon (IFN)-γ production and in the generation of IFN–γ–producing T helper 1 (Th1) cells. Here we show that the IL-12 receptor (IL12R) β2 subunit, a recently cloned binding and signal transducing component of the IL-12R, is expressed on human Th1 but not Th2 clones and is induced during differentiation of human naive cells along the Th1 but not the Th2 pathway. IL-12 and type I but not type II interferons induce expression of the IL-12R β2 chain during in vitro T cell differentiation after antigen receptor triggering. The selective expression and regulation of the IL-12R β2 subunit may help to understand the basis of Th1/Th2 differentiation and may provide therapeutic options for altering the Th1/Th2 balance in several immuno-pathological conditions such as autoimmune diseases and allergies.     

Characterization of Early Cytokine Responses and an Interleukin (IL)-6–dependent Pathway of Endogenous Glucocorticoid Induction during Murine Cytomegalovirus Infection

Early infection with murine cytomegalovirus (MCMV) induces circulating levels of interleukin (IL)-12, interferon (IFN)-γ, and tumor necrosis factor (TNF). Studies presented here further characterize these responses by defining kinetics and extending evaluation to include IL-1, IL-6, and glucocorticoids. IL-12 p40, IFN-γ, TNF, IL-1α, and IL-6 were shown to be increased, but IL-1β was undetectable, in serum of MCMV-infected mice. The IL-12 p40, IFN-γ, TNF, and IL-6 responses were dramatic with peak levels reaching >150–10,000 pg/ml at 32–40 h after infection and rapidly declining thereafter. Glucocorticoid induction, peaking at 36 h and reaching 30-fold increases above control values, accompanied the cytokine responses. Mice with cytokine deficiencies or neutralized cytokine function demonstrated that IL-6 was the pivotal mediator of the glucocorticoid response, with IL-1 contributing to IL-6 production. The IL-6 requirement appeared to be specific for virus-type stimuli as the synthetic analogue of viral nucleic acid, polyinosinic-polycytidylic acid, also induced IL-6–dependent glucocorticoid release, but treatments with the bacterial product lipopolysaccharide and a non-immune physical restraint stressor elicited IL-6–independent responses. Collectively, the results identify IL-6 as a primary mediator of glucocorticoid induction, and elucidate specific pathways of interactions between immune and neuroendocrine systems during viral infection.The cytokines IL-12, IFN-γ, TNF, IL-1, and IL-6 are induced under conditions of sepsis with gram-negative bacteria and in response to administration of the gram-negative bacterial product endotoxin, i.e., LPS (1, 2). High levels of these cytokines contribute to pathologies characterized as endotoxin-induced shock with wasting, thymic atrophy, and life-threatening states (1–3). Circulating TNF, IL-1, and/or IL-6, elicited as a cascade after exposure to LPS (4–6) or after administration of purified cytokines (7), induce the steroid hormones glucocorticoids. Induction is largely a result of hypothalamic-pituitary-adrenal (HPA)¹ axis activation through stimulating hypothalamus production of corticotropin-releasing hormone (CRH), which induces pituitary release of adrenocorticotropin hormone (ACTH) for stimulation of adrenal gland glucocorticoid production. Glucocorticoids can suppress multiple immune functions, including cytokine production and T cell responses (4, 8, 9). Thus, the immune and neuroendocrine systems can communicate to provide feedback inhibition mechanisms limiting immune responses.In addition to stimulation as a result of cytokine responses to bacterial LPS, glucocorticoid release through the HPA axis occurs as part of circadian rhythm (10) and is induced by a variety of other stimuli including physical or cognitive stress (11), a synthetic analogue for viral nucleic acids, i.e., polyinosinic-polycytidylic acid (poly I:C) (12), and turpentine induction of inflammation (3, 13). The precise pathways for HPA axis activation under each of these conditions has yet to be fully elucidated, and little is known about endogenous induction in response to infections. If glucocorticoids are elicited during challenge with pathogens, they may shape or modulate down-stream T cell functions as well as control acute detrimental cytokinemediated pathologies (4, 8, 9).This laboratory has been examining cytokine responses and functions during viral infections (14–16). In particular, responses to infections of mice with the cytopathic (14–18) murine cytomegalovirus (MCMV) are being investigated. Our group has shown that systemic levels of IL-12, IFN-γ, and TNF are induced at early times after infection (15, 16). The present studies were undertaken to more precisely define the early MCMV-elicited cytokine responses, to extend characterization to IL-1 and IL-6, and to determine the effects of cytokine expression on endogenous glucocorticoid responses. Our results demonstrate that MCMV stimulates dramatic and tightly regulated early IL-12, IFN-γ, TNF, IL-1, and IL-6 responses with an accompanying glucocorticoid response. The key mediator of glucocorticoid induction is shown to be IL-6 with IL-1 acting to stimulate IL-6 production. These studies define an IL-6–dependent pathway for endogenous glucocorticoid induction. Moreover, they suggest that distinct pathways are in place for communication between immune and neuroendocrine systems during infections with different types of pathogens.     

Interferon γ Derived from CD4+ T Cells Is Sufficient to Mediate T Helper Cell Type 1 Development

Interferon γ (IFN-γ) has been implicated in T helper type 1 (Th1) cell development through its ability to optimize interleukin 12 (IL-12) production from macrophages and IL-12 receptor expression on activated T cells. Various systems have suggested a role for IFN-γ derived from the innate immune system, particularly natural killer (NK) cells, in mediating Th1 differentiation in vivo. We tested this requirement by reconstituting T cell and IFN-γ doubly deficient mice with wild-type CD4⁺ T cells and challenging the mice with pathogens that elicited either minimal or robust IL-12 in vivo (Leishmania major or Listeria monocytogenes, respectively). Th1 cells developed under both conditions, and this was unaffected by the presence or absence of IFN-γ in non-T cells. Reconstitution with IFN-γ–deficient CD4⁺ T cells could not reestablish control over L. major, even in the presence of IFN-γ from the NK compartment. These data demonstrate that activated T cells can maintain responsiveness to IL-12 through elaboration of endogenous IFN-γ without requirement for an exogenous source of this cytokine.     

The Initial 96 Hours of Invasive Pulmonary Aspergillosis: Histopathology,Comparative Kinetics of Galactomannan and (1→3)-β-d-Glucan,and Consequences of Delayed Antifungal Therapy

Acute invasive pulmonary aspergillosis is a rapidly progressive and frequently lethal infection. Relatively little is known about early events in the pathogenesis and relationship between the cell wall biomarkers galactomannan and (1→3)-β-d-glucan. The consequences of delayed antifungal therapy are also poorly defined. A persistently neutropenic rabbit model of invasive pulmonary aspergillosis was used to describe the histopathology of early invasive pulmonary aspergillosis and the kinetics of galactomannan and (1→3)-β-d-glucan. The time course of both molecules was mathematically modeled by using a population methodology, and Monte Carlo simulations were performed. The effect of progressive delay in the administration of amphotericin B deoxycholate 1 mg/kg at 24, 48, 72, and 96 h postinoculation on fungal burden, lung weight, pulmonary infarct score, and survival was determined. Histopathology showed phagocytosis of conidia by pulmonary alveolar macrophages at 4 h postinoculation. At 12 to 24 h, there was a progressive focal inflammatory response with conidial germination and hyphal extension. Subsequently, hyphae invaded into the contiguous lung. Galactomannan and (1→3)-β-d-glucan had similar trajectories, and both exhibited considerable interindividual variability, which was reflected in Monte Carlo simulations. Concentrations of both molecules began to rise <24 h postinoculation before pulmonary hemorrhagic infarction was present. Delays of 72 and 96 h in the administration of amphotericin B resulted in fungal burdens and lung weights that were indistinguishable from those of controls, respectively. Galactomannan and (1→3)-β-d-glucan have similar kinetics and are comparable biomarkers of early invasive pulmonary aspergillosis. Antifungal treatment at ≥48 h postinoculation is associated with suboptimal therapeutic outcomes.Acute invasive pulmonary aspergillosis is a leading cause of morbidity and mortality in immunocompromised patients. There have been considerable efforts to improve the diagnostic accuracy and therapeutic outcomes associated with this frequently lethal infection. A better understanding of the relationship of clinically relevant biomarkers and the pathogenesis of invasive pulmonary aspergillosis would facilitate further development of strategies to identify and treat patients at the earliest possible time.Galactomannan and (1→3)-β-d-glucan are complex carbohydrate cell wall molecules produced by Aspergillus spp. The diagnostic and prognostic value of these biomarkers in experimental models and humans is relatively well characterized (7, 12, 17, 18, 23). Despite this, there is little understanding of the relationship of the time course of galactomannan and (1→3)-β-d-glucan to early events in the pathogenesis of invasive pulmonary aspergillosis, and no studies that have rigorously compared their kinetics in laboratory animals or humans.Recently, we described the kinetics of galactomannan in persistently neutropenic rabbits with early invasive pulmonary aspergillosis (12). In the present study, we extend our previous findings by defining the critical histopathological events in early invasive pulmonary aspergillosis and further characterize and compare the kinetics of the circulating fungal antigens galactomannan and (1→3)-β-d-glucan. We further explore the consequences of delayed antifungal therapy with amphotericin B deoxycholate to provide insight into the period after inoculation in which favorable therapeutic outcomes can be secured in profoundly immunocompromised hosts.     

Prostaglandin E2 regulates Th17 cell differentiation and function through cyclic AMP and EP2/EP4 receptor signaling

Prostaglandins, particularly prostaglandin E2 (PGE2), play an important role during inflammation. This is exemplified by the clinical use of cyclooxygenase 2 inhibitors, which interfere with PGE2 synthesis, as effective antiinflammatory drugs. Here, we show that PGE2 directly promotes differentiation and proinflammatory functions of human and murine IL-17–producing T helper (Th17) cells. In human purified naive T cells, PGE2 acts via prostaglandin receptor EP2- and EP4-mediated signaling and cyclic AMP pathways to up-regulate IL-23 and IL-1 receptor expression. Furthermore, PGE2 synergizes with IL-1β and IL-23 to drive retinoic acid receptor–related orphan receptor (ROR)-γt, IL-17, IL-17F, CCL20, and CCR6 expression, which is consistent with the reported Th17 phenotype. While enhancing Th17 cytokine expression mainly through EP2, PGE2 differentially regulates interferon (IFN)-γ production and inhibits production of the antiinflammatory cytokine IL-10 in Th17 cells predominantly through EP4. Furthermore, PGE2 is required for IL-17 production in the presence of antigen-presenting cells. Hence, the combination of inflammatory cytokines and noncytokine immunomodulators, such as PGE2, during differentiation and activation determines the ultimate phenotype of Th17 cells. These findings, together with the altered IL-12/IL-23 balance induced by PGE2 in dendritic cells, further highlight the crucial role of the inflammatory microenvironment in Th17 cell development and regulation.Prostaglandins, prostaglandin E2 (PGE2) in particular, play an important role in the regulation of inflammatory responses. PGE2 is a key mediator of pyrexia, hyperalgesia, and arterial dilation, which increases blood flow to inflamed tissues and, in combination with enhanced microvascular permeability, results in edema. The relevance of this pathway in promoting inflammation is supported by the clinical use of cyclooxygenase inhibitors, which interfere with prostaglandin synthesis and are used as effective antiinflammatory agents (1). However, PGE2 can also exert antiinflammatory properties and is a negative regulator of neutrophil, monocyte, and lymphocyte function, particularly of Th1 cells that produce IFN-γ (2). This apparent paradox has puzzled many investigators for decades. The interplay among PGE2, IL-23, and IL-1β biology may now provide an explanation of this paradox.Th17 cells have been recognized as a unique subset of effector T cells that are distinct from the Th1 and Th2 subsets (3–6), and they have been implicated as potent effectors of autoimmune disorders, such as multiple sclerosis, psoriasis, arthritis, and inflammatory bowel disease (IBD) (7–10). We and others have previously reported that IL-23 and IL-1β are crucial factors during development of human Th17 cells (9, 11, 12). In addition, IL-23 and the IL-23–dependent Th17 cell population play essential roles in chronic inflammation and autoimmunity (13).PGE2 has been shown to exacerbate inflammation and disease severity in murine models of IBD and collagen-induced arthritis through the IL-23–IL-17 pathway (14, 15). These effects have been attributed to actions of PGE2 on innate cells, as PGE2 enhances the production of IL-23 and IL-1β in macrophages and DCs, while down-regulating IL-12 production (16). A recent report has shown that PGE2, together with IL-23, favors the expansion of human Th17 cells from PBMCs, and that PGE2 enhances IL-17 production induced by IL-23 from memory CD4⁺ cells (17). However, the molecular mechanism of PGE2-mediated signaling during human Th17 cell development has not yet been examined.In this study, we show that PGE2 acts directly on both human and murine T cells to enhance Th17 development and effector cytokine production. In human T cells, PGE2 acts via the prostaglandin receptor EP2- and EP4-mediated signaling and cAMP pathways to up-regulate IL-23 and IL-1 receptor expression. Furthermore, PGE2 synergizes with IL-1β and IL-23 to drive retinoic acid receptor–related orphan receptor (ROR)-γt, IL-17, IL-17F, CCL20, and CCR6 expression, which is consistent with the previously reported Th17 phenotype (8, 18). While enhancing Th17 cytokine expression mainly through EP2, PGE2 differentially regulates IFN-γ production and inhibits production of the antiinflammatory cytokine IL-10 in both naive and memory Th17 cells predominantly through EP4. Hence, the combination of inflammatory cytokines and noncytokine immunomodulators, such as PGE2, during differentiation and activation determines the ultimate phenotype of Th17 cells. These findings, together with the altered IL-12/IL-23 balance induced by PGE2 in dendritic cells, further highlight the crucial role of the inflammatory microenvironment in Th17 cell development and regulation.     

A partial form of recessive STAT1 deficiency in humans

Complete STAT1 deficiency is an autosomal recessive primary immunodeficiency caused by null mutations that abolish STAT1-dependent cellular responses to both IFN-α/β and IFN-γ. Affected children suffer from lethal intracellular bacterial and viral diseases. Here we report a recessive form of partial STAT1 deficiency, characterized by impaired but not abolished IFN-α/β and IFN-γ signaling. Two affected siblings suffered from severe but curable intracellular bacterial and viral diseases. Both were homozygous for a missense STAT1 mutation: g.C2086T (P696S). This STAT1 allele impaired the splicing of STAT1 mRNA, probably by disrupting an exonic splice enhancer. The misspliced forms were not translated into a mature protein. The allele was hypofunctional, because residual full-length mRNA production resulted in low but detectable levels of normally functional STAT1 proteins. The P696S amino acid substitution was not detrimental. The patients’ cells, therefore, displayed impaired but not abolished responses to both IFN-α and IFN-γ. We also show that recessive STAT1 deficiencies impaired the IL-27 and IFN-λ1 signaling pathways, possibly contributing to the predisposition to bacterial and viral infections, respectively. Partial recessive STAT1 deficiency is what we believe to be a novel primary immunodeficiency, resulting in impairment of the response to at least 4 cytokines (IFN-α/β, IFN-γ, IFN-λ1, and IL-27). It should be considered in patients with unexplained, severe, but curable intracellular bacterial and viral infections.     

2012-2018年山东省济南市A族β溶血性链球菌分子分型特征研究

目的了解济南市A族β溶血性链球菌（GAS)的emm分型特点，为猩红热病原学监测提供数据。方法收集2012 — 2018年济南市GAS菌株，应用PCR方法扩增emm基因，扩增产物经测序、比对，获得菌株emm基因型。结果共获得GAS菌株143株，检测到5个emm基因型，其中emm12占55.2%（79/143），emm1占42.0%（60/143），其他emm基因型占2.8%（4/143）。 2015年和2016年仅分到11株菌，均为emm12。 患者分离菌株116株，分为4种emm基因型，emm1（46株）和emm12（67株）共占97.4%（113/116），emm22（1株）和emm75（2株）共占2.6%（3/116）。 143株GAS菌株中，菌株数量排在前3位的分别为市中区（85株）、槐荫区（35株）和历城区（9株）。结论2012 — 2018年济南市GAS菌株优势基因型为emm12和emm1。 2013年和2014年以emm1为主，其余年份以emm12为主。     

Behavior of Visceral Leishmania donovani in an Experimentally Induced T Helper Cell 2 (Th2)-Associated Response Model

Although implicated in the clinical expression of human visceral leishmaniasis, a disease-exacerbating T helper cell 2 (Th2)-associated immune response involving interleukin-4 (IL-4) and/ or IL-10 is not readily detectable in experimental visceral infection. To overcome this obstacle to analyzing visceral Leishmania donovani in this relevant immunopathogenetic environment, we sought a model in which a Th2 response induces noncuring infection. Four initial approaches were tested primarily in BALB/c mice which control intracellular L. donovani via an IL-12– and interferon-γ (IFN-γ)–dependent Th1 mechanism: (a) modifying the cytokine milieu when the parasite is first encountered (treatment with exogenous IL-4 or anti–IL-12), (b) providing sustained endogenous exposure to a Th2 cytokine (infection of IL-4 transgenic mice), (c) increasing the parasite challenge inoculum, and (d) injecting heat-killed L. major promastigotes (HKLMP) to induce a cross-reactive Th2 response to live L. donovani. Only the last approach generated a functional Th2-type response that induced disease exacerbation accompanied by inhibition of tissue granuloma assembly. In HKLMP-primed BALB/c mice, prophylaxis with anti–IL-4, anti–IL-10, or exogenous IL-12 (but not IFN-γ) readily restored resistance. In primed mice with established visceral infection, treatment with either IL-12 or IFN-γ also successfully induced antileishmanial activity. The results in this model (a) suggest that rather than acting alone, IL-4 and IL-10 may act in concert to prevent acquisition of resistance to L. donovani, (b) reemphasize the capacity of IL-12 to reverse early Th2-related effects, and (c) demonstrate that Th1 cytokines (IL-12, IFN-γ) have therapeutic action in an established systemic infection despite the presence of a disease-exacerbating Th2-type response.     

GVS-12 attenuates non-alcoholic steatohepatitis by suppressing inflammatory responses via PPARγ/STAT3 signaling pathways

Non-alcoholic steatohepatitis (NASH), a type of fatty liver disease, is characterized by excessive inflammation and fat accumulation in the liver. Peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone has great potential in protecting against the development of NASH. However, long-term usage of rosiglitazone probably leads to many adverse reactions. In this research, GVS-12 was designed and synthesized as a PPARγ agonist with high selectivity, evidenced by increasing the activity of the PPARγ reporter gene and promoting the mRNA expression of the PPARγ responsive gene cluster of differentiation 36 (CD36). It was noteworthy that GVS-12 could ameliorate dysfunction and lipid accumulation by down-regulating the mRNA expression of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the liver of high fat diet (HFD)-induced rats and palmitic acid (PA)-stimulated hepatocellular carcinoma G2 (HepG2) cells. Moreover, PPARγ siRNA (siPPARγ) markedly diminished GVS-12 induced the down-regulation of mRNA expression of IL-1β, IL-6 and TNF-α in PA-stimulated HepG2 cells. Additionally, GVS-12 could reduce the phosphorylation level of STAT3 and up-regulate the protein expression of a suppressor of cytokine signaling 3 (SOCS3), which could be reversed by siPPARγ. In detail, SOCS3 siRNA (siSOCS3) diminished the inhibitory effect of GVS-12 on the mRNA expression of IL-1β, IL-6 and TNF-α. In conclusion, GVS-12 suppressed the development of NASH by down-regulating the mRNA expression of IL-1β, IL-6 and TNF-α via PPARγ/STAT3 signaling pathways.

Non-alcoholic steatohepatitis (NASH), a type of fatty liver disease, is characterized by excessive inflammation and fat accumulation in the liver.     

In vivo regulation of interleukin 1β in patients with cryopyrin-associated periodic syndromes

The investigation of interleukin 1β (IL-1β) in human inflammatory diseases is hampered by the fact that it is virtually undetectable in human plasma. We demonstrate that by administering the anti–human IL-1β antibody canakinumab (ACZ885) to humans, the resulting formation of IL-1β–antibody complexes allowed the detection of in vivo–produced IL-1β. A two-compartment mathematical model was generated that predicted a constitutive production rate of 6 ng/d IL-1β in healthy subjects. In contrast, patients with cryopyrin-associated periodic syndromes (CAPS), a rare monogenetic disease driven by uncontrolled caspase-1 activity and IL-1 production, produced a mean of 31 ng/d. Treatment with canakinumab not only induced long-lasting complete clinical response but also reduced the production rate of IL-1β to normal levels within 8 wk of treatment, suggesting that IL-1β production in these patients was mainly IL-1β driven. The model further indicated that IL-1β is the only cytokine driving disease severity and duration of response to canakinumab. A correction for natural IL-1 antagonists was not required to fit the data. Together, the study allowed new insights into the production and regulation of IL-1β in man. It also indicated that CAPS is entirely mediated by IL-1β and that canakinumab treatment restores physiological IL-1β production.IL-1α and β, which were originally described as leukocytic pyrogens (1), are important regulators of the response to tissue damage and infections and mediate symptoms of fever, fatigue, pain, arthritis, and the hepatic acute phase responses including synthesis of C-reactive protein (CRP) and serum amyloid A protein (SAA) (2). Although studies using recombinant IL-1 in cancer patients confirmed the causative role of IL-1 for many of these symptoms (3), its direct investigation in man is hampered by the inability to detect IL-1 in biological fluids. cryopyrin-associated periodic syndromes (CAPS) is a clinical disease syndrome resulting from heterozygous gain-of-function mutations in NLRP3, the gene encoding cryopyrin. These mutations are supposed to promote release of IL-1, thereby providing an excellent paradigm for studying human IL-1 in vivo (4, 5). CAPS patients present with a spectrum of autoinflammatory diseases (6–11) involving almost all organ systems. NLRP3 mutations result in overactivation of caspase 1, the enzyme which cleaves the precursors of IL-1β, IL-18, and IL-33, members of the IL-1 family of cytokines, into their active forms (12). Although pro–IL-1α is not a substrate of caspase 1, recent studies in mice indicate that secretion of bioactive IL-1α requires functional NLRP3 (13) and activated caspase-1 (14). The recombinant IL-1 receptor antagonist (IL-1Ra) anakinra and the IL-1 receptor type I (IL-1RI) fusion protein rilonacept (IL-1 trap) have both induced clinical response in CAPS, demonstrating that signaling via the IL-1RI is crucial for the pathogenesis of CAPS (15–17). This strongly implies that neither IL-18 nor IL-33 plays significant roles in the disease, as neither of these two cytokines signals via the IL-1RI, and suggests that the disease is caused by overproduction of IL-1. By administering the human anti–IL-1β antibody canakinumab to CAPS patients, we provide evidence in this paper that IL-1β is pivotal in the pathogenesis of CAPS. Treatment with the antibody allowed the detection of IL-β and the creation of a mathematical model, which indicates that the in vivo production rate of IL-1β is fivefold higher in CAPS as compared with healthy subjects. Furthermore, in vivo IL-β production could be completely restored in these patients after canakinumab treatment.     

Plasma Levels of Interleukin 12 Family Cytokines and Their Relevant Cytokines in Adult Patients with Chronic Immune Thrombocytopenia before and after High-Dose Dexamethasome Treatment

Objective

We aimed to investigate the expression of interleukin 12 (IL-12) family cytokines (IL-12, IL-23, IL-27 and IL-35) and their relevant cytokines (IFN-γ, IL-4, IL-17A and IL-10) in patients with chronic immune thrombocytopenia (cITP) as well as the effect of high-dose dexamethasone (HD-DXM) treatment on this expression.

Materials and Methods

DXM was administered orally at a dose of 40 mg per day for 4 consecutive days to 38 patients with cITP. We measured the plasma levels of IL-12p70, IL-23, IL-27, IFN-γ, IL-4 and IL-17A before and after treatment and also in 36 matched healthy controls, by means of FlowCytomix™ technology. The plasma levels of IL-10 and IL-35 were measured by enzyme-linked immunosorbent assay.

Results

Significantly higher plasma levels of IL-12p70, IL-23, IL-27, IFN-γ and IL-17A were observed in cITP patients than in controls (p < 0.01), and after HD-DXM treatment, these levels decreased significantly (p < 0.01). However, significantly lower plasma levels of IL-4, IL-10 and IL-35 were observed in cITP patients than in controls (p < 0.01); after the HD-DXM treatment, these levels had increased significantly in the cITP patients (p < 0.01). Moreover, the cytokine levels of patients who attained a complete response returned to the levels of normal controls (p > 0.05) but were not corrected in the patients who had no response (p < 0.01).

Conclusions

The patients with cITP had abnormal expression of the IL-12 family cytokines and their relevant cytokines levels, and HD-DXM treatment corrected the derangement of plasma cytokines. Measuring cytokine levels may help in the clinical assessment of cITP.Key Words: Immune thrombocytopenia, Interleukin 12, Cytokines, Dexamethasone     

Profile of serum cytokine concentrations in patients with gouty arthritis

ObjectiveThis study aimed to analyze the changes in serum inflammatory cytokines and anti-inflammatory cytokines in patients with gouty arthritis (GA).MethodsThe clinical data and serum samples in patients with gouty arthritis and those in healthy volunteers were collected in China-Japan Friendship Hospital from July 2018 to January 2019. Serum cytokine concentrations in patients with GA and volunteers (controls) were determined by a chemiluminescence method. The differences in cytokine concentrations were compared between the two groups.ResultsConcentrations of serum interleukin-1 beta (IL-1ß), tumor necrosis factor-alpha (TNF-α), IL-6, IL-8, and IL-4 were significantly higher in patients with acute GA than in controls. Serum concentrations of IL-1ß, TNF-α, IL-6, IL-8, and immunoglobulin E in patients with remission of GA were significantly lower, whereas concentrations of IL-10 and interferon-γ were significantly higher, compared with those in patients with acute GA.ConclusionThis study shows that serum concentrations of IL-1ß, TNF-α, IL-6, IL-8, and IL-4 are significantly elevated in patients with GA, and may be involved in the pathogenesis of GA.     

2011-2014年北京地区儿童咽扁桃体炎感染病例A组链球菌emm分型研究

目的 了解2011-2014年北京市儿童咽扁桃体炎感染病例A组链球菌(group A streptococcus,GAS)emm基因型别分布情况。 方法 采集2011-2014年北京地区36家医院儿科门、急诊咽扁桃体炎感染病例咽拭子标本,分离GAS菌株,用聚合酶链反应(PCR)方法扩增emm基因进行测序和分型,分析不同人群,和临床诊断结果的emm型别特征。 结果 共有739个病例纳入研究,检测到10种emm基因型和32种emm基因亚型。主要基因型为emm12和emm1,分别占所有型别比例的62.2%和35.0%;主要基因亚型为emm12.00和emm1.00,分别占所有亚型的比例为53.2%和31.9%;发现两种新的emm亚型,分别为st1258和st485。基因型emm12 GAS感染人群主要分布在中心城区,占59.8%;基因型emm1 GAS感染人群主要分布在北部郊区,占49.4%。这两种基因型的地区分布,时间分布和感染人群的平均年龄差异均有明显的统计学意义,人群性别构成差异无统计学意义。 结论 北京地区儿童GAS咽扁桃体炎感染病例emm基因优势型别为emm12和emm1,这两种型别在不同地区和年龄人群中的分布存在明显差异。     

Selective Expression and Functions of Interleukin 18 Receptor on T Helper (Th) Type 1 but not Th2 Cells

Interleukin (IL)-18 induces interferon (IFN)-γ synthesis and synergizes with IL-12 in T helper type 1 (Th1) but not Th2 cell development. We report here that IL-18 receptor (IL-18R) is selectively expressed on murine Th1 but not Th2 cells. IL-18R mRNA was expressed constitutively and consistently in long-term cultured clones, as well as on newly polarized Th1 but not Th2 cells. IL-18 sustained the expression of IL-12Rβ2 mRNA, indicating that IL-18R transmits signals that maintain Th1 development through the IL-12R complex. In turn, IL-12 upregulated IL-18R mRNA. Antibody against an IL-18R–derived peptide bound Th1 but not Th2 clones. It also labeled polarized Th1 but not Th2 cells derived from naive ovalbumin–T cell antigen receptor-αβ transgenic mice (D011.10). Anti–IL-18R antibody inhibited IL-18– induced IFN-γ production by Th1 clones in vitro. In vivo, anti–IL-18R antibody reduced local inflammation and lipopolysaccharide-induced mortality in mice. This was accompanied by shifting the balance from Th1 to Th2 responses, manifest as decreased IFN-γ and proinflammatory cytokine production and increased IL-4 and IL-5 synthesis. Therefore, these data provide a direct mechanism for the selective effect of IL-18 on Th1 but not Th2 cells. They also show that the synergistic effect of IL-12 and IL-18 on Th1 development may be due to the reciprocal upregulation of their receptors. Furthermore, IL-18R is a cell surface marker distinguishing Th1 from Th2 cells and may be a therapeutic target.     

Protective Effects of Human Lactoferrin during Aggregatibacter actinomycetemcomitans-Induced Bacteremia in Lactoferrin-Deficient Mice

Aggregatibacter actinomycetemcomitans, a periodontopathogen, has been associated with several systemic diseases. Herein, we report the protective effect of human lactoferrin (hLF) during A. actinomycetemcomitans bacteremia in lactoferrin knockout (LFKO^−/−) mice. The prophylactic, concurrent, and therapeutic intravenous (i.v.) administrations of hLF significantly cleared the bacteria from blood and organs. Nevertheless, all modes of hLF administration significantly decreased the concentrations of serum proinflammatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p70. Additionally, hLF administration significantly decreased hepatic and splenic proinflammatory cytokine expression levels compared to those in the non-hLF-treated group. Furthermore, administration of hLF decreased the serum C-reactive protein level, inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) gene expression levels in liver and spleen. hLF treatment has also resulted in a 6-fold decrease in spleen weight with the migration of typical inflammatory cells in infected mice as a result of decreased inflammatory response. These results reveal that hLF protects against A. actinomycetemcomitans bacteremia, as indicated by rapid bacterial clearance and decreased host proinflammatory mediators.     

CD40 Ligand Is Not Essential for Induction of Type 1 Cytokine Responses or Protective Immunity after Primary or Secondary Infection With Histoplasma capsulatum

The induction of type 1 immune responses (interleukin [IL]-12, interferon [IFN]-γ) has been shown to be important in mediating protection against many intracellular infections including Histoplasma capsulatum. Costimulatory molecules such as CD40 ligand (CD40L) have been shown to be a central regulator of type 1 responses in vivo. To study the role of CD40L in mediating protection against infection with H. capsulatum, CD40L-deficient (CD40L^−/−) and CD40L^+/+ mice were infected with H. capsulatum and assessed for various parameters. After a lethal challenge of H. capsulatum, CD40L^−/− mice were not substantially different from CD40L^+/+ mice in terms of mortality, fungal burden, or production of IFN-γ, IL-12, nitric oxide, or tumor necrosis factor α. Moreover, CD40L^−/− mice treated with anti–IFN-γ or anti–IL-12 at the time of infection had accelerated mortality, providing further evidence that IL-12 and IFN-γ are produced in vivo in the absence of CD40L. In addition, CD40L^−/− mice infected with a sublethal dose of H. capsulatum survived infection, whereas all mice infected with the same dose and treated with anti–IFN-γ had accelerated mortality, demonstrating that IFN-γ but not CD40L was essential for primary immunity to H. capsulatum infection. Interestingly, depletion of either CD4⁺ or CD8⁺ T cells resulted in accelerated mortality in CD40L^−/− mice, suggesting a critical role for these cells in response to infection. Finally, CD40L^−/− mice initially infected with a sublethal dose of H. capsulatum were protected from secondary infection with a lethal dose of H. capsulatum, demonstrating that CD40L is not required for the maintenance of memory immunity.     

深圳地区儿童A群致病性链球菌感染流行现状及M蛋白基因分型分析

目的 了解深圳地区儿童A群致病性链球菌(group A streptococcus,GAS)感染流行现状及其M蛋白基因(emm)分布状况,为该区GAS疫苗的研制提供科学依据。方法 收集2014年3月～2015年12月来医院门诊和住院部就诊的急性咽炎、急性化脓性扁桃体炎、风湿热及猩红热患儿的咽拭子及皮肤化脓性感染伤口分泌物共1 634例,分别对标本进行细胞培养与鉴定,分析不同年龄儿童GAS感染流行情况,并对GAS的M蛋白N末端进行PCR扩增测序,分析GAS的emm基因分型及其在疾病中的分布情况。结果 1 634例标本中共分离鉴定出61株GAS,检出率为3.73%(61/1 634),其中学龄前和学龄儿童分别检测出14株和47株,检出率分别为22.95%(14/61)和77.05%(47/61),学龄儿童GAS感染率明显高于学龄前儿童,两者结果之间差异有统计学意义(χ2=32.035,P<0.01),但学龄儿童不同年龄段GAS感染率之间比较差异无统计学意义(χ2=1.572,P>0.05); GAS在急性咽炎和化脓性扁桃体炎的患儿中检出率最高,分别为34.43%(21/61)和27.87%(17/61); 61株GAS的emm基因型以emml和emm12最为多见,分别占40.98%(25/61)和29.51%(18/61)。结论 深圳地区学龄儿童GAS感染率明显高于学龄前儿童,且以急性咽炎和急性化脓性扁桃体炎患儿检出率最高。61株GAS感染的emm基因以emm1和emm12为主,因此,各地加强GAS的emm基因分型研究,可为该区GAS疫苗的研制提供重要的分子流行病学依据。