Association Between Interleukin 35 Gene Single Nucleotide Polymorphisms and the Uveitis Immune Status in a Chinese Han Population

The effects of IL-27 and IL-35 gene variation and expression levels on the susceptibility and clinical manifestations of pulmonary tuberculosis

Inflammatory cytokines have crucial roles in the pathogenesis of tuberculosis (TB), and interleukin (IL)-27 and IL-35 have a pro-inflammatory and anti-inflammatory effect on many diseases, including infectious diseases. Therefore, we evaluated the relationship between IL-27 and IL-35 gene polymorphism, expression levels, and pulmonary TB (PTB) susceptibility. Nine single-nucleotide polymorphisms (SNPs) in the IL-27 gene (rs181206, rs153109, and rs17855750) and the IL-35 gene (rs4740, rs428253, rs9807813, rs2243123, rs2243135, and rs568408) were genotyped by the SNPscan technique in 497 patients with PTB and 501 controls. There was no significant difference regarding the genotype and allele frequencies of the above SNPs in the IL-27 and IL-35 genes between patients with PTB and controls. Haplotype analysis showed that the frequency of the GAC haplotype in the IL-35 gene was significantly decreased in patients with PTB when compared to controls (p = 0.036). Stratified analysis suggested that the frequency of the IL-27 rs17855750 GG genotype was significantly increased in patients with PTB with fever. Moreover, the lower frequency of the IL-35 rs568408 GA genotype was associated with drug-induced liver injury in patients with PTB. The IL-35 rs428253 GC genotype, as well as the rs4740 AA genotype and A allele, showed significant relationships with hypoproteinemia in patients with PTB. When compared with controls, the IL-27 level was significantly increased in patients with PTB. Taken together, IL-35 gene variation might contribute to a protective role on the susceptibility to PTB, and IL-27 and IL-35 gene polymorphisms were associated with several clinical manifestations of patients with PTB.

Risk factors, clinical features and treatment of Behçet's disease uveitis

Behçet's disease is a systemic vasculitis frequently associated with intraocular inflammation. Recent findings identified independent clinical clusters in Behçet's disease, each involving distinct combinations of affected organs. Ocular Behçet's disease, mainly manifested as uveitis, is characterized as an independent cluster with a low likelihood of association with other system involvements, such as intestinal, cardiovascular, or central nervous system. A prevailing theory suggests that the pathogenesis of the disease is multifactorial, where a variety of genetic and infectious agents may interact with each other to cause the disease. Among sporadic cases, the human leukocyte antigen (HLA) genes, including HLA-B51, HLA-A26, HLA-B15, and HLA-B5701, have been found to be a key component conferring genetic susceptibility. Outside the HLA region, a set of susceptibility variants are identified, closely related to interleukin (IL)-23/IL-17 pathway, tumor necrosis factor (TNF) signaling, and pattern recognition receptor systems. Microbial infections, such as Streptococcus sanguinis, Mycobacterium tuberculosis, and Herpes simplex virus (HSV), are linked to play the triggering of disease in immunogenetically predisposed individuals. Clinically, due to the notable relapsing-remitting course of ocular Behçet's disease, the prevention of recurrent attack would be the primary treatment goal. Combination of corticosteroids and immunomodulatory drugs, such as anti-TNF agents, interferon, and conventional immunosuppressants (e.g. cyclosporine, azathioprine), have been the mainstream regimen for the disease. Future research may focus on comparing the effectiveness of immunomodulatory drugs and identifying the most suitable subgroups for a specific drug on the basis of the knowledge of the molecular heterogeneity of the disease.

Photoreceptor Cells Constitutively Express IL-35 and Promote Ocular Immune Privilege

Interleukin-27 is constitutively secreted by microglia in the retina or brain, and upregulation of IL-27 during neuroinflammation suppresses encephalomyelitis and autoimmune uveitis. However, while IL-35 is structurally and functionally similar to IL-27, the intrinsic roles of IL-35 in CNS tissues are unknown. Thus, we generated IL-35/YFP-knock-in reporter mice (p35-KI) and demonstrated that photoreceptor neurons constitutively secrete IL-35, which might protect the retina from persistent low-grade inflammation that can impair photoreceptor functions. Furthermore, the p35-KI mouse, which is hemizygous at the il12a locus, develops more severe uveitis because of reduced IL-35 expression. Interestingly, onset and exacerbation of uveitis in p35-KI mice caused by extravasation of proinflammatory Th1/Th17 lymphocytes into the retina were preceded by a dramatic decrease of IL-35, attributable to massive death of photoreceptor cells. Thus, while inflammation-induced death of photoreceptors and loss of protective effects of IL-35 exacerbated uveitis, our data also suggest that constitutive production of IL-35 in the retina might have housekeeping functions that promote sterilization immunity in the neuroretina and maintain ocular immune privilege.

Interleukin-35 ameliorates cardiovascular disease by suppressing inflammatory responses and regulating immune homeostasis

The immune response is of great significance in the initiation and progression of a diversity of cardiovascular diseases involving pro-and anti-inflammatory cytokines. Interleukin-35 (IL-35), a cytokine of the interleukin-12 family, is a novel anti-inflammation and immunosuppressive cytokine, maintaining inflammatory suppression and regulating immune homeostasis. The role of IL-35 in cardiovascular diseases (CVDs) has aroused enthusiastic attention, a diversity of experimental or clinical evidence has indicated that IL-35 potentially has a pivot role in protecting against cardiovascular diseases, especially atherosclerosis and myocarditis. In this review, we initiate an overview of the relationship between Interleukin-35 and cardiovascular diseases, including atherosclerosis, acute coronary syndrome, pulmonary hypertension, abdominal aortic aneurysm, heart failure, myocardial ischemia-reperfusion, aortic dissection and myocarditis. Although the specific molecular mechanisms entailing the protective effects of IL-35 remain an unsolved issue, targeted therapies with IL-35 might provide a promising and effective solution to prevent and cure cardiovascular diseases.

Icariin alleviates uveitis by targeting peroxiredoxin 3 to modulate retinal microglia M1/M2 phenotypic polarization

Uveitis causes blindness and critical visual impairment in people of all ages, and retinal microglia participate in uveitis progression. Unfortunately, effective treatment is deficient. Icariin (ICA) is a bioactive monomer derived from Epimedium. However, the role of ICA in uveitis remains elusive. Our study indicated that ICA alleviated intraocular inflammation in vivo. Further results showed the proinflammatory M1 microglia could be transferred to anti-inflammatory M2 microglia by ICA in the retina and HMC3 cells. However, the direct pharmacological target of ICA is unknown, to this end, proteome microarrays and molecular simulations were used to identify the molecular targets of ICA. Data showed that ICA binds to peroxiredoxin-3 (PRDX3), increasing PRDX3 protein expression in both a time- and a concentration-dependent manner and promoting the subsequent elimination of H₂O₂. In addition, GPX4/SLC7A11/ACSL4 pathways were activated accompanied by PRDX3 activation. Functional tests demonstrated that ICA-derived protection is afforded through targeting PRDX3. First, ICA-shifted microglial M1/M2 phenotypic polarization was no longer detected by blocking PRDX3 both in vivo and in vitro. Next, ICA-activated GPX4/SLC7A11/ACSL4 pathways and downregulated H₂O₂ production were also reversed via inhibiting PRDX3 both in vivo and in vitro. Finally, ICA-elicited positive effects on intraocular inflammation were eliminated in PRDX3-deficient retina from experimental autoimmune uveitis (EAU) mice. Taking together, ICA-derived PRDX3 activation has therapeutic potential for uveitis, which might be associated with modulating microglial M1/M2 phenotypic polarization.