IL-23 in infections, inflammation, autoimmunity and cancer: possible role in HIV-1 and AIDS

Age-specific dynamics of neutralizing antibodies, cytokines, and chemokines in response to La Crosse virus infection in mice

La Crosse virus (LACV) is a primary cause of pediatric arboviral encephalitis in the United States, particularly affecting children aged 16 years or younger. This age-related susceptibility extends to murine models, where weanling mice (3 weeks old) succumb to LACV infection, while adults (≥6 weeks old) demonstrate resistance. Despite its clinical relevance, the host immune response to LACV is not fully understood. In this study, we investigated the roles of neutralizing antibodies (nAbs), cytokines, and chemokines in weanling and adult mice following infection with 5 × 105 plaque-forming units (PFU) of LACV. Weanling mice demonstrated early disease onset with elevated peripheral viremia, but passive transfer of adult serum, confirmed to have nAbs, to naïve weanlings prior to infection completely rescued them from death. Moreover, adult mice had increased Th1 cytokines, Th9/Th17/Th22/Treg cytokines, and many chemokines. In contrast, weanlings had higher Th2 cytokines, correlating with symptoms onset. Flow cytometry and intracellular cytokine staining further demonstrated that weanling mice produced higher levels of IL-4 by CD4+ and CD8+ T cells compared to adults, regardless of infection status. Conversely, LACV-infected adult mice had increased IFN-γ production by CD8+ T cells compared to uninfected controls. Finally, the adoptive transfer of splenocytes from immune adult mice to naïve weanlings delayed neurological symptoms and improved survival. In conclusion, this study links nAbs and cytokine and chemokine responses to protective immunity in adult mice, contrasting with the pathogenesis seen in weanlings. These findings underscore the importance of further research into innate and adaptive immune mechanisms during LACV infection.IMPORTANCELa Crosse virus (LACV) is a primary cause of pediatric encephalitis in the United States, with an impact on children aged 16 years or younger. This age-related susceptibility is recapitulated in mouse models, where young mice succumb to LACV-induced disease, while adults demonstrate resistance. Our understanding of host responses to LACV remains underexplored. This study sheds light on the dynamics of neutralizing antibodies (nAbs), cytokines, and chemokines following LACV infection in both adult and weanling mice. Our study reveals age-specific variations in viremia, neutralizing antibody titers, survivability, and levels of cytokines and chemokines. Adult mice exhibit significantly elevated levels of Th1 cytokines, contrasting with elevated levels of Th2 cytokines observed in weanling mice, often coinciding with the onset of symptoms. These data reveal age-specific dynamics in cytokines and chemokines associated with protective versus pathogenic immunity, emphasizing the need for further studies on innate and adaptive immunity.

Association between a single nucleotide polymorphism of the IL23R gene and tuberculosis in a Chinese Han population: a case‒control study

BACKGROUND

Severe tuberculosis constitutes a significant menace to human safety and well-being, with a considerable mortality rate. The severity of tuberculosis can be impacted by genetic variations in host genes, particularly single nucleotide polymorphisms (SNPs).

METHODS

A case‒control study was undertaken, encompassing a cohort of 1137 tuberculosis patients (558 with severe tuberculosis and 579 with mild tuberculosis), alongside 581 healthy controls within the age range of fifteen to forty-five years. Whole blood DNA was extracted from all participants, and three tag polymorphisms (rs1884444, rs7518660, rs7539625) of the IL23R gene were selectively identified and genotyped.

RESULTS

No significant correlation was observed between the IL23R gene polymorphisms (rs1884444, rs7518660, and rs7539625) and tuberculosis. Upon comparing the tuberculosis group with the healthy control group, the mild tuberculosis group with the healthy control group, and the severe tuberculosis group with the healthy control group, the obtained P-values were> 0.05. However, in the comparison between severe tuberculosis and mild tuberculosis, the presence of rs1884444 G alleles exhibited a significantly increased risk of severe tuberculosis after adjusting for age and sex (OR^a: 1.199, 95% CI: 1.009-1.424; P^a=0.039, respectively). In subgroup analysis, after accounting for confounding factors, including age and sex, rs1884444 G alleles continued to demonstrate a significantly heightened risk of severe tuberculosis. Nonetheless, the comparison between the multisystemic tuberculosis group and the mild tuberculosis group was no significant difference. Notably, rs1884444 of the IL23R gene exhibited a noteworthy association with the risk of severe tuberculosis in the comparison between severe tuberculosis and mild tuberculosis before and after adjusting for age and sex (OR^a: 1.301, 95% CI: 1.030-1.643; P^a=0.027, respectively). Furthermore, the presence of the rs1884444 G allele exhibited a significantly increased risk of severe tuberculosis after adjusting for age and sex in the comparison between tuberculous meningitis and mild tuberculosis (OR^a: 1.646, 95% CI: 1.100-2.461; P^a=0.015, respectively).

CONCLUSIONS

The present study suggests that there is no significant association between IL23R gene polymorphism and tuberculosis susceptibility in the Chinese Han population. However, it does indicate a potential link between IL23R polymorphism and an increased risk of developing severe tuberculosis.

Cold Atmospheric Plasma Exerts Antimicrobial Effects in a 3D Skin Model of Cutaneous Candidiasis

Cutaneous candidiasis is characterized by an overgrowth of Candida leading to skin inflammation and infection. Similar to bacteria, Candida can develop tolerance to common antifungal drugs. Cold atmospheric plasma (CAP), with its proven antimicrobial properties, offers a promising alternative to the prevailing methods. Because of plasma heterogeneity each new device must be tested individually for its effectiveness. Antimicrobial activity is usually studied using planktonic microorganisms or animal models, making it difficult to extrapolate the results to the human system. Therefore, a 3D skin model of cutaneous candidiasis for the antimicrobial testing of CAP was established. First, the reaction of the 3D-skin model to Candida infection was examined using various histological and molecular-biological methods. Infection with C. albicans resulted in increased expression and secretion of pro-inflammatory cytokines and augmented expression of antimicrobial peptides. Within 48 h, hyphal growth spread throughout the model and caused tissue damage. Second, the CAP treatment was employed. It was shown that CAP significantly reduced the spread of the yeast in the infected skin models as well as decreased the expression and secretion of the infection markers. The plasma device exhibited a high antifungal activity by completely inhibiting hyphal growth and reducing inflammation at the highest treatment duration.

Application of Monoclonal Antibody Drugs in Treatment of COVID-19: a Review

Coronavirus infection can have various degrees of severity and outcomes. In some cases, it causes excessive production of pro-inflammatory cytokines, a so-called cytokine storm, leading to acute respiratory distress syndrome. Unfortunately, the exact pathophysiology and treatment, especially for severe cases of COVID-19, are still uncertain. Results of preliminary studies showed that immunosuppressive therapy, such as interleukin (IL)-6, IL-1, and TNF-α antagonists commonly used in rheumatology, can be considered as treatment options for COVID-19, especially in severe cases. The review focused on the most common and currently studied monoclonal antibody drugs, as well as up-to-date data on the pathogenesis of COVID-19, host immune response against SARS-CoV-2 and its association with cytokine storm. It also covered effects of interleukin (IL)-6, IL-1, and TNF-α blockers on the course of coronavirus infection and outcome in patients treated for the main autoimmune disease and subsequently infected with COVID-19.

Risk of Candida Infection and Serious Infections in Patients with Moderate-to-Severe Psoriasis Receiving Biologics: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Biological agents used to treat moderate-to-severe plaque psoriasis have been associated with Candida infection and other serious infections. It is, however, necessary to verify whether biologic agents increase the risk of Candida infection and serious infections and whether these risks vary among biologics.

METHODS

PubMed, EMBASE, and Cochrane Library were searched for eligible randomized controlled trials (RCTs) from their inception to December 2021. Results from individual RCT were pooled using Peto's method with a fixed-effects model, and I ² was calculated to assess the heterogeneity. A Cochrane collaboration tool was used to examine bias risk, and Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) were used to assess the quality of evidence.

RESULTS

This study included 48 published articles with data from 52 RCTs involving 27297 participants. The anti-interleukin (IL)-17 agents (95% confidence interval (CI) = 1.54-3.45, P < 0.0001) and anti-IL-12/23 agents (95% CI = 1.69-3.83, P < 0.0001) were associated with an increased risk of Candida infection compared with placebos, but there was no difference in Candida infection risk between anti-IL-17 agents and tumor necrosis factor inhibitors (TNFi) (95% CI = 0.92-3.07, P=0.09). There was no evidence that the biological agents increased the risk of serious infections in adult psoriasis (95% CI = 0.93-2.06, P=0.11) or that the biologics differed in the risk of serious infections.

CONCLUSIONS

Our results indicated that anti-IL-17 agents, especially secukinumab, were associated with the increased risk of Candida infection. The clinically used biological agents did not increase the risk of serious infections.

Characterization of the IL-17 and CD4+ Th17 Cells in the Clinical Course of Dengue Virus Infections

The aims of this study were to determine the involvement of interleukin 17 (IL-17) and IL-17-producing cells in dengue pathogenesis. Blood samples from dengue virus (DENV)-infected patients were collected on different days after the onset of symptoms. Patients were classified according to 1997 World Health Organization guidelines. Our study examined 152 blood samples from dengue fever (DF, n = 109) and dengue hemorrhagic fever (DHF, n = 43) patients and 90 blood samples from healthy controls (HC). High serum concentrations of IL-17A and IL-22 were also associated with DHF (IL-17A [DHF vs. DF, p < 0.01; DHF vs. HC, p < 0.0001]; IL-22 [DHF vs. DF, p < 0.05; DHF vs. HC, p < 0.0001]). Moreover, there was a positive correlation between serum levels of IL-17A and IL-23, a key cytokine that promotes IL-17-based immune responses (r = 0.4089, p < 0.0001). Consistent with the IL-17-biased immune response in DHF patients, we performed ex vivo activation of peripheral blood mononuclear cells (PBMCs) from DHF patients and flow cytometry analysis showed a robust IL-17-biased immune response, characterized by a high frequency of CD4+IL-17+ producing cells. Our results suggests IL-17-producing cells and their related cytokines can play a prominent role in this viral disease.

IL-23 costimulates antigen-specific MAIT cell activation and enables vaccination against bacterial infection

Mucosal-associated invariant T (MAIT) cells are activated in a TCR-dependent manner by antigens derived from the riboflavin synthesis pathway, including 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil (5-OP-RU), bound to MHC-related protein-1 (MR1). However, MAIT cell activation in vivo has not been studied in detail. Here, we have found and characterized additional molecular signals required for optimal activation and expansion of MAIT cells after pulmonary Legionella or Salmonella infection in mice. We show that either bone marrow-derived APCs or non-bone marrow-derived cells can activate MAIT cells in vivo, depending on the pathogen. Optimal MAIT cell activation in vivo requires signaling through the inducible T cell costimulator (ICOS), which is highly expressed on MAIT cells. Subsequent expansion and maintenance of MAIT-17/1-type responses are dependent on IL-23. Vaccination with IL-23 plus 5-OP-RU augments MAIT cell-mediated control of pulmonary Legionella infection. These findings reveal cellular and molecular targets for manipulating MAIT cell function under physiological conditions.

Blood-based inflammation biomarkers of neurocognitive impairment in people living with HIV

Inflammation in people living with HIV (PLWH) correlates with severity of HIV-associated neurocognitive disorders. The objective of this study is to identify blood-based markers of neurocognitive function in a demographic balanced cohort of PLWH. Seven neurocognitive domains were evaluated in 121 seropositive Black/African American, Non-Hispanic White, and White Hispanic men and women using computerized assessments. Associations among standardized neurocognitive function and HIV-related parameters, relevant sociodemographic variables, and inflammation-associated cytokines measured in plasma and cellular supernatants were examined using multivariate and univariate regression models. Outlier and covariate analyses were used to identify and normalize for education level, CD4 T cell count, viral load, CNS and drug abuse comorbidities, which could influence biomarker and neurocognitive function associations. Plasma levels of chemokine (C-C motif) ligand (CCL) 8 significantly associated with memory, complex attention, cognitive flexibility, psychomotor speed, executive function, and processing speed. Plasma tissue inhibitor of metalloproteinases 1 associated with the aforementioned domains except memory and processing speed. In addition, plasma interleukin-23 significantly associated with processing speed and executive function. Analysis of peripheral blood cell culture supernatants revealed no significant markers for neurocognitive function. In this cohort, CD4 T cell count and education level also significantly associated with neurocognitive function. All identified inflammatory biomarkers demonstrated a negative correlation to neurocognitive function. These cytokines have known connections to HIV pathophysiology and are potential biomarkers for neurocognitive function in PLWH with promising clinical applications.

IL-23 and PSMA-targeted duo-CAR T cells in Prostate Cancer Eradication in a preclinical model

Background

Prostate cancer is one of the most common adult malignancies in men, and nearly all patients with metastatic prostate cancer can develop and receive resistance to primary androgen deprivation therapy (ADT), a state known as metastatic castration-resistant prostate cancer (mCRPC). Recent reports demonstrated the great breakthroughs made by the chimeric antigen receptor T (CAR-T) cell therapy, which is significantly different from traditional T cells therapies. In spite of the progress of CAR-T technology in the treatment of lymphoma, leukemia, and other blood system tumor, there are still many difficulties in the treatment of solid tumors by CAR-T technology.

Methods

In this report, we designed a panel of IL23mAb-PSMA-CARs, including PSMA-CAR, IL23mAb-T2A-PSMA-CAR, IL23mAb-PSMA-CAR, and PSMA-CAR (soluble IL23mAb). And we studied the function of these CARs in mice model.

Results

Co-culture experiments with different CAR T cells have normal lysis function in vitro. The duo-CAR T cells co-expressing the IL-23mAb and PSMA-mAb had a significant higher population than the rest three different CAR T cells in co-culturing experiments at day 28, 35 and 42. A panel of cytokines were differentially secreted at higher amounts in IL23mAb-T2A-PSMA-CAR T cells than CAR T cells in other groups. In NOD/SCID IL-2 gamma (NSG) mice model, IL23mAb-T2A-PSMA-CAR T cells functioned significantly better than CAR T cells from the other groups and eradicated the tumor from these mice starting at day 14 post T cells injection and regained the body weight immediately. In IL23mAb-T2A-PSMA-CAR mice, CD45RO+ CD8+ T cells and CD127+ CD4+ CAR T cells were significantly increased. RNA sequencing revealed a difference expression pattern of genes in IL23mAb-T2A-PSMA-CAR mice. A reverse infusion experiment under the same model further proved the tumor eradication function of IL23mAb-T2A-PSMA-CAR T cells.

Conclusions

We found that IL-23mAb combined PSMA CARs worked better than PSMA CAR only in Prostate Cancer Eradication, and we further discussed the mechanisms among different IL-23mAb combined PSMA CARs in Prostate Cancer Eradication.

Immunoregulatory Functions of the IL-12 Family of Cytokines in Antiviral Systems

Members of the interleukin 12 (IL-12) family have been known to be inflammatory factors since their discovery. The IL-12 family consists of IL-12, IL-23, IL-27, IL-35, and a new member, IL-39, which has recently been identified and has not yet been studied extensively. Current literature has described the mechanisms of immunity of these cytokines and potential uses for therapy and medical cures. IL-12 was found first and is effective in combatting a wide range of naturally occurring viral infections through the upregulation of various cytokines to clear the infected cells. IL-23 has an essential function in immune networks, can induce IL-17 production, and can antagonize inhibition from IL-12 in the presence of T helper (Th) 17 cells, resulting in type II IFN (IFN-γ) regulation. IL-27 has a competitive relationship to IL-35 because they both include the same subunit, the Epstein–Barr virus-induced gene3 (EBi3). This review provides a simple introduction to the IL-12 family and focuses on their functions relevant to their actions to counteract viral infections.

Promoting effects of IL‑23 on myocardial ischemia and reperfusion are associated with increased expression of IL‑17A and upregulation of the JAK2‑STAT3 signaling pathway

Interleukin (IL)-23, as a novel pro-inflammatory cytokine, is important in several inflammatory diseases, including myocardial ischemia and reperfusion (I/R) injury, however, the underlying mechanism remains to be elucidated. The present study was designed to investigate the specific role of IL-23 in myocardial I/R injury, and whether the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2-STAT3) signaling pathway, one of the important downstream signaling pathways of IL-23, and the IL-17A downstream pro-inflammatory cytokine, were involved. Anesthetized rats underwent different treatments with adenovirus (Ad) vectors (Ad-GFP, Ad-IL-23, Anti-IL-23 or Ad-IL-23+AG490) and were then subjected to ischemia for 30 min prior to 4 h reperfusion. The effects of the upregulation and downregulation of IL-23 on myocardial injury, inflammatory responses in myocardial tissue, and myocardial apoptosis were measured accordingly. In addition, the levels of phosphorylated (P-)JAK2 and P-STAT3 were measured to assess the activity of the JAK2-STAT3 signaling pathway. The results demonstrated that there was an increased expression of IL-23 in the myocardial tissue exposed to myocardial I/R injury (P<0.05). The upregulation of IL-23 significantly increased the infarct size and the expression levels of lactate dehydrogenase and creatine kinase (P<0.05). The upregulation of IL-23 significantly increased inflammatory responses, as reflected by the high expression levels of IL-17A, IL-6, tumor necrosis factor-α in the myocardial tissues (P<0.05). Furthermore, the upregulation of IL-23 significantly facilitated the decrease in the B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein ratio, and the increases in the myocardial apoptotic index and expression of caspase-3 induced by myocardial I/R (P<0.05). IL-23 also activated the JAK2-STAT3 signaling pathway, upregulating the expression levels of P-JAK2 and P-STAT3 in the myocardial tissues (P<0.05). Treatment with AG490, an inhibitor of JAK2-STAT3, partially attenuated the pro-inflammatory and pro-apoptotic effects of IL-23 (P<0.05). The results of the present study suggested that IL-23 aggravated myocardial I/R injury by promoting inflammatory responses and myocardial apoptosis, which may be associated with high expression levels of IL-17A and upregulation of the JAK2-STAT3 signaling pathway.

Monocyte-lymphocyte fusion induced by the HIV-1 envelope generates functional heterokaryons with an activated monocyte-like phenotype

Enveloped viruses induce cell-cell fusion when infected cells expressing viral envelope proteins interact with target cells, or through the contact of cell-free viral particles with adjoining target cells. CD4⁺ T lymphocytes and cells from the monocyte-macrophage lineage express receptors for HIV envelope protein. We have previously reported that lymphoid Jurkat T cells expressing the HIV-1 envelope protein (Env) can fuse with THP-1 monocytic cells, forming heterokaryons with a predominantly myeloid phenotype. This study shows that the expression of monocytic markers in heterokaryons is stable, whereas the expression of lymphoid markers is mostly lost. Like THP-1 cells, heterokaryons exhibited FcγR-dependent phagocytic activity and showed an enhanced expression of the activation marker ICAM-1 upon stimulation with PMA. In addition, heterokaryons showed morphological changes compatible with maturation, and high expression of the differentiation marker CD11b in the absence of differentiation-inducing agents. No morphological change nor increase in CD11b expression were observed when an HIV-fusion inhibitor blocked fusion, or when THP-1 cells were cocultured with Jurkat cells expressing a non-fusogenic Env protein, showing that differentiation was not induced merely by cell-cell interaction but required cell-cell fusion. Inhibition of TLR2/TLR4 signaling by a TIRAP inhibitor greatly reduced the expression of CD11b in heterokaryons. Thus, lymphocyte-monocyte heterokaryons induced by HIV-1 Env are stable and functional, and fusion prompts a phenotype characteristic of activated monocytes via intracellular TLR2/TLR4 signaling.

The Role of Interleukin-23 in the Early Development of Emphysema in HIV1(+) Smokers

Rationale. Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1⁺ smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1⁺ smokers contains increased levels of inflammatory cytokines compared to HIV1⁻ smokers, we hypothesized that upregulation of lung cytokines in HIV1⁺ smokers may be functionally related to increased MMP-9 expression. Methods. Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1⁻ healthy nonsmokers, HIV1⁻ healthy smokers, HIV1⁻ smokers with low diffusing capacity (DL_CO), HIV1⁺ nonsmokers, and HIV1⁺ smokers with low DL_CO. Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1⁻ smokers with low DL_CO and HIV1⁺ smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1⁺ individuals, with greater expression in AM of HIV1⁺ smokers with low DL_CO. Infection with HIV1 in vitro induced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte cocultures in vitro induced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9. Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1⁺ smokers and suggests that Th17 related inflammation may play a role.

IL-23 prevents IL-13-dependent tissue repair associated with Ly6C(lo) monocytes in Entamoeba histolytica-induced liver damage

BACKGROUND & AIMS

The IL-23/IL-17 axis plays an important role in the pathogenesis of autoimmune diseases and the pathological consequences of infection. We previously showed that immunopathologic mechanisms mediated by inflammatory monocytes underlie the severe focal liver damage induced by the protozoan parasite, Entamoeba histolytica. Here, we analyze the contribution of the IL-23/IL-17 axis to the induction and subsequent recovery from parasite-induced liver damage.

METHODS

IL-23p19(-/-), IL-17A/F(-/-), CCR2(-/-), and wild-type (WT) mice were intra-hepatically infected with E. histolytica trophozoites and disease onset and recovery were analyzed by magnetic resonance imaging. Liver-specific gene and protein expression during infection was examined by qPCR, microarray, FACS analysis and immunohistochemistry. Immuno-depletion and substitution experiments were performed in IL-23p19(-/-) and WT mice to investigate the role of IL-13 in disease outcome.

RESULTS

Liver damage in infected IL-23p19(-/-), IL-17A/F(-/-), and CCR2(-/-) mice was strongly attenuated compared with that in WT mice. IL-23p19(-/-) mice showed reduced accumulation of IL-17 and CCL2 mRNA and proteins. Increased numbers of IL-13-producing CD11b(+)Ly6C(lo) monocytes were associated with disease attenuation in IL-23p19(-/-) mice. Immuno-depletion of IL-13 in IL-23p19(-/-) mice reversed this attenuation and treatment of infected WT mice with an IL-13/anti-IL-13-mAb complex supported liver recovery.

CONCLUSIONS

The IL-23/IL-17 axis plays a critical role in the immunopathology of hepatic amebiasis. IL-13 secreted by CD11b(+)Ly6C(lo) monocytes may be associated with recovery from liver damage. An IL-13/anti-IL13-mAb complex mimics this function, suggesting a novel therapeutic option to support tissue healing after liver damage.

Stromal fibroblasts support dendritic cells to maintain IL-23/Th17 responses after exposure to ionizing radiation

Cross talk between DCs and FBs in understanding the effects of IR in DC function.

Dendritic cell function is modulated by stromal cells, including fibroblasts. Although poorly understood, the signals delivered through this crosstalk substantially alter dendritic cell biology. This is well illustrated with release of TNF-α/IL-1β from activated dendritic cells, promoting PGE₂ secretion from stromal fibroblasts. This instructs dendritic cells to up-regulate IL-23, a key Th17-polarizing cytokine. We previously showed that ionizing radiation inhibited IL-23 production by human dendritic cells in vitro. In the present study, we investigated the hypothesis that dendritic cell-fibroblast crosstalk overcomes the suppressive effect of ionizing radiation to support appropriately polarized Th17 responses. Radiation (1–6 Gy) markedly suppressed IL-23 secretion by activated dendritic cells (P < 0.0001) without adversely impacting their viability and consequently, inhibited the generation of Th17 responses. Cytokine suppression by ionizing radiation was selective, as there was no effect on IL-1β, -6, -10, and -27 or TNF-α and only a modest (11%) decrease in IL-12p70 secretion. Coculture with fibroblasts augmented IL-23 secretion by irradiated dendritic cells and increased Th17 responses. Importantly, in contrast to dendritic cells, irradiated fibroblasts maintained their capacity to respond to TNF-α/IL-1β and produce PGE₂, thus providing the key intermediary signals for successful dendritic cell-fibroblasts crosstalk. In summary, stromal fibroblasts support Th17-polarizing cytokine production by dendritic cells that would otherwise be suppressed in an irradiated microenvironment. This has potential ramifications for understanding the immune response to local radiotherapy. These findings underscore the need to account for the impact of microenvironmental factors, including stromal cells, in understanding the control of immunity.

Identification and expression analysis of two interleukin-23α (p19) isoforms, in rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar

Interleukin (IL)-23 is a heterodimeric IL-12 family cytokine composed of a p19 α-chain, linked to a p40 β-chain that is shared with IL-12. IL-23 is distinguished functionally from IL-12 by its ability to induce the production of IL-17, and differentiation of Th17 cells in mammals. Three isoforms of p40 (p40a, p40b and p40c) have been found in some 3R teleosts. Salmonids also possess three p40 isoforms (p40b1, p40b2 and p40c) although p40a is missing, and two copies (paralogues) of p40b are present that have presumably been retained following the 4R duplication in this fish lineage. Teleost p19 has been discovered recently in zebrafish, but to date there is limited information on expression and modulation of this molecule. In this report we have cloned two p19 paralogues (p19a and p19b) in salmonids, suggesting that a salmonid can possess six potential IL-23 isoforms. Whilst Atlantic salmon has two active p19 genes, the rainbow trout p19b gene may have been pseudogenized. The salmonid p19 translations share moderate identities (22.8-29.9%) to zebrafish and mammalian p19 molecules, but their identity was supported by structural features, a conserved 4 exon/3 intron gene organisation, and phylogenetic tree analysis. The active salmonid p19 genes are highly expressed in blood and gonad. Bacterial (Yersinia ruckeri) and viral infection in rainbow trout induces the expression of p19a, suggesting pathogen-specific induction of IL-23 isoforms. Trout p19a expression was also induced by PAMPs (poly IC and peptidoglycan) and the proinflammatory cytokine IL-1β in primary head kidney macrophages. These data may indicate diverse functional roles of trout IL-23 isoforms in regulating the immune response in fish.

Th17 cells in autoimmune and infectious diseases

The view of CD4 T-cell-mediated immunity as a balance between distinct lineages of Th1 and Th2 cells has changed dramatically. Identification of the IL-17 family of cytokines and of the fact that IL-23 mediates the expansion of IL-17-producing T cells uncovered a new subset of Th cells designated Th17 cells, which have emerged as a third independent T-cell subset that may play an essential role in protection against certain extracellular pathogens. Moreover, Th17 cells have been extensively analyzed because of their strong association with inflammatory disorders and autoimmune diseases. Also, they appear to be critical for controlling these disorders. Similar to Th1 and Th2 cells, Th17 cells require specific cytokines and transcription factors for their differentiation. Th17 cells have been characterized as one of the major pathogenic Th cell populations underlying the development of many autoimmune diseases, and they are enhanced and stabilized by IL-23. The characteristics of Th17 cells, cytokines, and their sources, as well as their role in infectious and autoimmune diseases, are discussed in this review.

Phosphorylated STAT3 and PD-1 regulate IL-17 production and IL-23 receptor expression in Mycobacterium tuberculosis infection

We studied the factors that regulate IL-23 receptor expression and IL-17 production in human tuberculosis infection. Mycobacterium tuberculosis (M. tb)-stimulated CD4(+) T cells from tuberculosis patients secreted less IL-17 than did CD4(+) T cells from healthy tuberculin reactors (PPD(+) ). M. tb-cultured monocytes from tuberculosis patients and PPD(+) donors expressed equal amounts of IL-23p19 mRNA and protein, suggesting that reduced IL-23 production is not responsible for decreased IL-17 production by tuberculosis patients. Freshly isolated and M. tb-stimulated CD4(+) T cells from tuberculosis patients had reduced IL-23 receptor and phosphorylated STAT3 (pSTAT3) expression, compared with cells from PPD(+) donors. STAT3 siRNA reduced IL-23 receptor expression and IL-17 production by CD4(+) T cells from PPD(+) donors. Tuberculosis patients had increased numbers of PD-1(+) T cells compared with healthy PPD(+) individuals. Anti-PD-1 antibody enhanced pSTAT3 and IL-23R expression and IL-17 production by M. tb-cultured CD4(+) T cells of tuberculosis patients. Anti-tuberculosis therapy decreased PD-1 expression, increased IL-17 and IFN-γ production and pSTAT3 and IL-23R expression. These findings demonstrate that increased PD-1 expression and decreased pSTAT3 expression reduce IL-23 receptor expression and IL-17 production by CD4(+) T cells of tuberculosis patients.

In vivo effect of statins on the expression of the HIV co-receptors CCR5 and CXCR4

BACKGROUND

During the HIV-1 replication cycle, several molecules including chemokine receptors and cholesterol are crucial, and are therefore potential targets for therapeutic intervention. Indeed statins, compounds that inhibit cellular synthesis of cholesterol and have anti-inflammatory and immunomodulatory properties were shown to inhibit HIV-1 infection by R5 tropic strains but not by X4 strains in vitro, mainly by altering the chemokine receptor/ligands axes. Therefore, the objective of this study was to characterize in vivo, the capacity of statins to modulate in HIV seronegative and chronically HIV-1-infected adults the expression of CCR5 and CXCR4, of their ligands and the tropism of circulating HIV-1 strains.

METHODS

Samples from asymptomatic HIV-1-infected adults enrolled in a clinical trial aimed at evaluating the antiretroviral activity of lovastatin were used to evaluate in vivo the modulation by lovastatin of CCR5, CXCR4, their ligands, and the shift in plasma viral tropism over one year of intervention. In addition, ten HIV negative adults received a daily oral dose of 40 mg of lovastatin or 20 mg of atorvastatin; seven other HIV negative individuals who received no treatment were followed as controls. The frequency and phenotype of immune cells were determined by flow-cytometry; mRNA levels of chemokine receptors and their ligands were determined by real-time PCR. Viral tropism was determined by PCR and sequencing, applying the clonal and clinical model of analyses.

RESULTS

Our study shows that long-term administration of lovastatin in HIV-infected individuals does not induce a shift in viral tropism, or induce a significant modulation of CCR5 and CXCR4 on immune cells in HIV-infected patients. Similar results were found in HIV seronegative control subjects, treated with lovastatin or atorvastatin, but a significant increase in CCL3 and CCL4 transcription was observed in these individuals.

CONCLUSIONS

These findings suggest that long-term administration of statins at therapeutic doses, does not significantly affect the expression of HIV-1 co-receptors or of their ligands. In addition it is important to point out that based on the results obtained, therapeutic administration of statins in HIV-infected patients with lipid disorders is safe in terms of selecting X4 strains.

ssICAM-1, IL-21 and IL-23 in patients with tick borne encephalitis and neuroborreliosis

Objective

There have been few reports on the role of Intercellular Adhesion Molecule 1 (ICAM-1), but not interleukin-21 (IL-21) and interleukin-23 (IL-23) in tick-borne encephalitis (TBE) and neuroborreliosis (NB). We postulate that these two interleukins may participate in the early phase of TBE and NB.

The aim of the study was to measure serum and cerebrospinal fluid (CSF) concentration of ICAM-1, IL-21 and IL-23 in patients with TBE and NB before treatment and to assess their usefulness in the diagnosis and monitoring of inflammatory process in TBE and NB.

Methods

Forty-three patients hospitalized in The Department of Infectious Diseases and Neuroinfections of Medical University in Bialystok, Poland, were included in the study. Patients were divided into three groups: TBE, NB and CG. Pre-treatment blood and CSF samples were obtained from all patients. ELISA kits (DRG Instruments, Germany) were used to measure the concentration of IL-21, IL-23 and sICAM-1.

Results

Significant differences between TBE/CG and NB/CG concentration of sICAM-1 were found only in the CSF. CSF IL-21 levels in NB were lower than in TBE.

In TBE, a strong negative correlation between CSF concentration of IL-21 and IL-23 and monocyte count in CSF was observed. Negative correlation between IL-21 in CSF and neutrophil count was also noted. Serum IL-23 correlated positively with leukocytes and platelet count in serum.

In NB, a strong positive correlation between serum IL-21 and platelet count and negative correlation between IL-21 in serum and CSF with pleocytosis was observed.

Conclusions

Increased sICAM-1 concentration in TBE and NB may be a proof of brain–blood barrier disturbances in the early phase of these diseases. IL-21 and IL-23 do not appear to play an important role in the pathogenesis of the early stages of TBE and NB.