Background: Patients with atopic dermatitis (AD) exhibit phenotypic variability in ethnicity and IgE status. In addition, some patients develop other allergic conditions, such as allergic rhinitis (AR), in subsequent life. Understanding the heterogeneity of AD would be beneficial to phenotype-specific therapies.

Methods: Twenty-eight Chinese AD patients and 8 healthy volunteers were enrolled in the study. High-throughput transcriptome sequencing was conducted on lesional and nonlesional skin samples from 10 AD patients and matched normal skin samples from 5 healthy volunteers. Identification of differentially expressed genes (DEGs), KEGG pathway analyses, and sample cluster analyses were conducted in the R software environment using the DEseq2, ClusterProfiler, and pheatmap R packages, respectively. qRT-PCR, Western blotting, and ELISA were used to detect gene expression levels among subtypes. Correlation analysis was performed to further investigate their correlation with disease severity.

Results: A total of 25,798 genes were detected per sample. Subgroup differential expression analysis and functional enrichment analysis revealed significant changes in the IL17 signaling pathway in Chinese EAD patients but not in IAD patients. DEGs enriched in cytokine-cytokine receptor interactions and gland secretion were considered to be associated with atopic march. Further investigations confirmed a marked IL17A upregulation in Chinese EAD with a positive relationship with total IgE level and AD severity. In addition, increased IL17A in AD patients with AR demonstrated a closer association with AR severity than IL4R. Moreover, AQP5 and CFTR were decreased in the lesions of AD patients with AR. The CFTR mRNA expression level was negatively associated with the skin IL17A level and AR severity.

Conclusion: Our research characterized marked Th17 activation in Chinese EAD patients, and altered expression of IL17A, IL4R, AQP5, and CFTR in AD patients with AR was associated with AR severity. It partially explained the phenotypic differences of AD subtypes and provided potential references for endotype-targeted therapy.

Keywords: atopic dermatitis; atopic march; extrinsic AD; heterogeneity; intrinsic AD.

Background: Atractylodes lancea (Thunb) DC. (AL) and bioactive compounds β-eudesmol and atractylodin have been demonstrated in the in vitro and in vivo studies for their potential clinical use in cholangiocarcinoma. The study was a randomized, double-blinded, placebo-controlled phase I clinical trial to evaluate the immunomodulatory effect of AL in human subjects.

Methods: The modulatory effects of AL and β-eudesmol and atractylodin on TNFα and IL6 expression in PBMCs were measured using real-time PCR. Blood samples were collected from forty-eight healthy subjects following oral administration of a single or multiple dosing of capsule formulation of the standardized AL extract or placebo. Serum cytokine profiles, lymphocyte subpopulations (B lymphocytes, CD8⁺ cytotoxic T lymphocytes, CD4⁺ T-helper lymphocytes, and NK cells), and cytotoxic activity of PBMCs against the cholangiocarcinoma cell line CL-6 were evaluated using cytometric bead array (CBA) with flow cytometry analysis.

Results: AL extract at almost all concentrations significantly inhibited both TNFα and IL6 expression in Con A-mediated inflammation in PBMCs. β-Eudesmol at all concentrations significantly inhibited only IL6 expression. Atractylodin at the lowest concentration significantly inhibited the expression of both cytokines, while the highest concentration significantly inhibited only IL6 expression. The administration of AL at a single oral dose of 1000 mg appeared to decrease IFNγ and IL10 and increase B cell, while significantly increase NK and CD4⁺ and CD8⁺ cells. A trend of increasing (compared with placebo) in the cytotoxic activity of PBMCs at 24 h of dosing was observed. AL at multiple dosing of 1000 mg for 21 days tended to decrease the production of all cytokines, while significantly inhibited IL17A production at 24 h of dosing. In addition, a significant increase in CD4⁺ and CD8⁺ cells was observed. A trend of increase in the cytotoxic activity of PBMCs was observed at 24 h but terminated at 48 h of dosing.

Conclusions: The results confirm the immunomodulatory activity of AL in humans. This activity, in complementary with the direct action of AL on inducing cholangiocarcinoma cell apoptosis, suggests its potential role for CCA control.

Trial registration: Retrospectively registered on 17 October 2020 [Thai Clinical Trials Registry (TCTR: www.clinical trials.in.th ) Number TCTR20201020001 #].

Keywords: Atractylodes lancea; Atractylodin; Cholangiocarcinoma; Immunomodulatory activity; β-Eudesmol.

Background: NOTCH signaling has been shown to play a role in the production of interleukin-22 (IL-22) by CD4⁺ T cells. Multiple T-helper (Th) cell populations secrete IL-22. Th22 (CD4⁺IL22⁺IFNγ^-IL17A^-) cells are a subgroup of CD4⁺ effector T cells that primarily generate IL-22. The regulatory mechanisms of the NOTCH signaling pathway involved in differentiation of the Th22 cell subset have not been completely elucidated. This study aimed to further explore the involvement of NOTCH signaling in Th22 differentiation.

Methods: In vitro combination of IL-6, IL-23, and tumor necrosis factor-α (TNF-α) treatment with naïve CD4⁺ T cells established the Th22 cell induced model. NOTCH signaling was activated by jagged-1 and inhibited by (2S)-N-[(3,5-difluorophenyl) acetyl]-L-alanyl-2-phenyl]glycine 1,1-dimethylethyl ester (DAPT). HES-1 siRNA and HES-1 vector were employed to knock down and induce overexpression of HES-1 to investigate the effect of NOTCH signaling on the differentiation of CD4⁺T cells into Th22 cells.

Results: We observed that the proportion of Th22 cells, along with Hes-1, Ahr, and Il-22 mRNA and protein expression, was increased by both jagged-1 and overexpression of HES-1. On the other hand, after the combined cytokine treatment of cells, and exposure to jagged-1 and DAPT or HES-1 siRNA, there was a decrease in the Th22 cell proportion, mRNA and protein expression of HES-1, AHR, and IL-22.

Conclusions: Our study demonstrates that HES-1 enhancement in AHR and IL-22 up-regulation of NOTCH signaling can promote the skewing of naïve CD4⁺T cells toward Th22 cells. Also, the results of our study show that HES-1 is a crucial factor in Th22 cell differentiation.

Keywords: CD4+ T cells; Differentiation; HES-1; NOTCH signaling; Th22.

Aim: Interleukin-17 (IL-17) family cytokines promote the host defense against mycobacterial infections. We have previously shown an association between IL17A variations and Bacillus Calmette-Guérin (BCG) osteitis. This paper evaluates the association of three IL17F polymorphisms with BCG osteitis after newborn vaccination.

Methods: IL17F rs763780, rs11465553 and rs7741835 single nucleotide polymorphisms (SNPs) were studied in 132 adults, who presented with BCG osteitis in infancy. The genotypes and minor allele frequencies (MAFs) were compared between cases and Finnish population-based controls (N=99) from the 1000 Genomes Project, and MAFs were compared between cases and allele data of Finnish subjects from the large genome aggregation database.

Results: There were no significant differences between former BCG osteitis patients and population-based controls in the IL17F rs763780 (wild 84.4% vs. 84.8%), rs11465553 (86.4% vs. 91.9%) or rs7741835 (65.7% vs. 67.7%) genotypes. Homozygous variant genotypes were only present in 1.5%, 0.8% and 3.8% of cases, respectively. Likewise, MAFs of the three IL17F SNPs did not substantially differ from those of 11252, 11939 and 1371 Finnish subjects, respectively, from the available genome aggregation database.

Conclusion: IL17F rs763780, rs11465553 and rs7741835 variations showed no association with the risk of BCG osteitis after newborn vaccination.

Keywords: Bacillus Calmette-Guérin; Gene polymorphism; Innate immunity; Interleukin-17F; Vaccination complications.

Second mitochondria-derived activator of caspase (SMAC) mimetics (SMs) are selective antagonists of the inhibitor of apoptosis proteins (IAPs), which activate noncanonical NF-κB signaling and promote tumor cell death. Through gene expression analysis, we found that treatment of CD4⁺ T cells with SMs during T helper 17 (T_H17) cell differentiation disrupted the balance between two antagonistic transcription factor modules. Moreover, proteomics analysis revealed that SMs altered the abundance of proteins associated with cell cycle, mitochondrial activity, and the balance between canonical and noncanonical NF-κB signaling. Whereas SMs inhibited interleukin-17 (IL-17) production and ameliorated T_H17 cell-driven inflammation, they stimulated IL-22 secretion. Mechanistically, SM-mediated activation of NF-κB-inducing kinase (NIK) and the transcription factors RelB and p52 directly suppressed <i><em>Il17a</em></i> expression and IL-17A protein production, as well as the expression of a number of other immune genes. Induction of IL-22 production correlated with the NIK-dependent reduction in cMAF protein abundance and the enhanced activity of the aryl hydrocarbon receptor. Last, SMs also increased IL-9 and IL-13 production and, under competing conditions, favored the differentiation of naïve CD4⁺ T cells into T_H2 cells rather than T_H17 cells. These results demonstrate that SMs shape the gene expression and protein profiles of T_H17 cells and inhibit T_H17 cell-driven autoimmunity.

Psoriasis is a chronic and recurrent dermatitis, mediated by keratinocytes and T cells. Several proinflammatory cytokines contribute to formation and maintenance of psoriatic plaque. The Th1/Th17 pathways and some of IL-1 family members were involved in psoriasis pathogenesis and could contribute to disease activity. Therefore, we sought to analyse skin transcript levels of IL17A, IL22, RORC, IL8, IFNG, IL33, IL36A, FOXP3, and IL10 and correlate with clinic of patients with plaque-type psoriasis. In order to conduct that, we collected punch biopsies from lesional skin and obtained tissue RNA. After reverse transcription, qRT-PCR quantified the relative mRNA expression. The main results revealed increased transcripts levels of IL17A, IFNG, and FOXP3 in moderate-severe patients. Despite this, only IL17A can increase the chance to worsen disease severity. We also observed many significant positive correlations between each transcript. In conclusion, IL17A is elevated in lesional skin from psoriasis patients and plays crucial role in disease severity.

Exposure to subacute ozone (O3) causes pulmonary neutrophil recruitment. In mice, this recruitment requires IL-17A. Ozone also causes expression of IL-23 and IL-1, which can induce IL-17A. The purpose of this study was to examine the hypothesis that IL-23 and IL-1 contribute to IL-17A expression and subsequent neutrophil recruitment after subacute O3 exposure. Wild-type, IL-23(-/-), and Flt3l(-/-) mice were exposed to air or 0.3 ppm O3 for 72 h. Flt3l(-/-) mice lack conventional dendritic cells (cDC) that can express IL-23 and IL-1. Other wild-type mice were pre-treated with saline or the IL-1R1 antagonist anakinra prior to O3 exposure. After exposure, bronchoalveolar lavage (BAL) was performed and lung tissue harvested. The results indicated that pulmonary Il17a mRNA abundance and IL-17A(+) F4/80(+) cells were significantly reduced in O3-exposed IL-23(-/-) vs in wild-type mice. In contrast, anakinra had no effect on Il23a or Il17a pulmonary mRNA abundance or on BAL concentrations of the neutrophil survival factor G-CSF, but anakinra did reduce BAL neutrophil numbers, likely because anakinra also reduced BAL IL-6. Compared to air, O3 caused a significant increase in DC numbers in wild-type, but not in Flt3(-/-) mice. However, there was no significant difference in Il23a or Il17a mRNA abundance or in BAL neutrophil count in O3-exposed Flt3(-/-) vs in wild-type mice. From these results, it was concluded that IL-23 but not IL-1 contributes to the IL-17A expression induced by subacute O3 exposure. Induction of IL-23 by O3 does not appear to require cDC.

Refolding of human interleukin 17A (IL-17A) has been reported; however, the key refolding protocol was not robust enough to deliver consistent results and to be easily scaled up for crystallization. Here we report an optimized refolding method for IL-17A. Although co-crystal structures of IL-17A with ligands have been obtained with a high-affinity peptide and an anti-IL-17A Fab as stabilizers, neither the production yield nor the characterization of the IL-17A/Fab complex was reported. To facilitate co-crystallization of IL-17A with small-molecule compounds derived from our DNA encoded library, we also describe the method for yield enhancement of anti-IL-17A Fab production and characterize the IL-17A/Fab complex for the first time, providing an essential prerequisite for structure-based drug discovery targeting IL-17A.

High interleukin 17A (IL17A) expression in hepatocellular carcinoma (HCC) tissue promotes HCC development. This study is explore a method to inhibit HCC growth by neutralizing IL17A in the HCC microenvironment. A novel type 5 adenoviral vector (Ad5) that carries DNA sequences encoding specific neutralizing IL17A recombinant antibody fragments was developed in this research. After locally injected into tumor tissues, the Ad5 transduced into tumor cells. This leading to the expression of the anti-IL17A recombinant antibody fragments in the HCC tissue and consequently to an inhibition of HCC growth by neutralizing IL17A. The stability of the antibody fragments was optimized by different structures design. Stable HCC cell lines that secrete IL17A continuously were constructed and showed stronger invasion and migration ability than control HCC cell lines. Additionally, the enhanced migration and invasion ability was partially reversed by applying the adenoviral vectors. These results suggest that IL17A might promote HCC growth by enhancing the invasion and migration ability of hepatoma cells. The antibody fragments from Ad5 neutralized IL17A locally in turn inhibited the growth of HCC tumors. In conclusion, the local administration of Ad5 vectors encoding IL17A-neutralizing antibody fragments provides a new option for HCC immunotherapy.

<AbstractText>The aim of the present study was to investigate the Th2/Th17 pathway in asthmatic patients and also the relationship to asthma severity and biomarkers of inflammation.</AbstractText><AbstractText>90 asthmatic patients, 51 patients with severe, 39 patients with mild asthma and 98 healthy controls were included. Skin prick tests, blood eosinophils, total serum IgE and exhaled FeNO were evaluated. Serum levels of IL-4, IL-5, IL-13, IL-6, IL-17A, IL-23 and TGFβ1 were determined by Flow Cytometry using a panel kit (AimPlex Biosciences). The SNP of <em>IL17A</em> (rs17880588) was genotyped using reverse transcriptase polymerase chain reaction (RT-PCR).</AbstractText><AbstractText>The genotype of the SNP in <em>IL17A</em> (rs 17880588) was similar among all three groups. Serum levels of IL-4, IL-5, IL-13, IL-6, IL-17A and IL-23 were higher in asthmatics compared to controls (p < 0.05). In addition, IL-17A and IL-4 serum levels were found significantly elevated in patients with allergic asthma (p < 0.05). Furthermore, IL-4, IL-5, IL-13 and IL-23 were found significantly higher in patients with eosinophil cut off values above 300 cells/μl (p < 0.05). IL-17A levels were positively correlated with FeNO values in severe asthmatics with eosinophils>400 cells/μl.</AbstractText><AbstractText>The above findings suggest the coexistence of Th2/Th17 pathway in severe, eosinophilic and in allergic asthma.</AbstractText>

Objective:To detect the differentially expressed genes of allergic rhinitis(AR) with asthma and screen the pathogenic genes. Method: Eight nasal mucosa tissue samples from patients with nasal septum deviation (healthy control group), eight nasal mucosa tissue samples from patients with allergic rhinitis（AR） and eight nasal mucosa tissue samples from patients with AR and asthma were collected. Allergy & Asthma PCR Array was used to analyze allergy related genes expression level. Result: Compared to the control group, there are 84 related genes were found and 15 genes were up-regulated, 69 genes were down-regulated. Furthermore, there are 17 genes（ADAM33, BCL6, IFNGR2, IL12A, IL12B, IL13RA1, IL17A, IL31, IL4R, IL5, KIT, LTB4R, MS4A2, RORC, STAT5A, STAT6, TBX21） differentially expressed. Compared AR with asthma group to the AR group, there was 1 gene differentially expressed(RORC). Conclusion: ADAM33, BCL6, IFNGR2, IL12A, IL12B, IL13RA1, IL17A, IL31, IL4R, IL5, KIT, LTB4R, MS4A2, RORC, STAT5A, STAT6, TBX21 are the possible pathogenic genes of AR with asthma. RORC may be the specific marker gene in asthma induced by allergic rhinitis.

BACKGROUND

Coronary artery disease (CAD) is a current major public health concern. Immunity and inflammation are involved in all phases of CAD and there is a dynamic balance between cells and molecules. Interleukin 17A (IL17A) concentrations are higher in male patients with acute myocardial infarction than in women. In this study, we evaluated if the IL17A concentrations in male CAD patients (MPs) differed from those in female patients (FPs) and male controls (MCs). Moreover, FPs were compared with female controls (FCs).

METHODS

This was a cross-sectional, prospective, and analytical study conducted between March 2012 and August 2013 that enrolled 40 patients (24 men and 16 women) with stable CAD and 20 healthy volunteers (12 men and 8 women) were selected as controls and were matched with the patients (1:2) for sex and age (± 3 years). Comparative analyses of IL17A concentrations in serum and cell culture with and without stimulation were performed between MPs and MCs, MPs and FPs, and FPs and FCs. The lower detection limit was 3.91 pg/mL.

RESULTS

The comparison of the IL17A concentrations showed: after 48 hours of cell culture with stimulus: MP = 451.67 (99.02 - 892.58) vs. MC = 135 (3.91 - 285), P = 0.04; after 48 hours of cell culture with stimulus: MP = 451.67 (99.02 - 892.58) vs. FP = 131.21 (3.91 - 231.97), P = 0.02; after 48 hours of cell culture with stimulus: FP = 131.21 (3.91 - 231.97) vs. FC = 173.78 (3.91 - 642), P = 0.24.

CONCLUSIONS

This study revealed higher IL17A concentrations in the stimulated cells isolated from the MPs than in those isolated from FPs and MCs. These findings support the hypothesis that when exposed to certain stimuli, cells isolated from MPs with chronic CAD may produce higher IL17A concentrations than those from FPs and MCs.

The human commensal microflora plays an essential role in modulating the immune response to control homeostasis. Staphylococcus epidermidis, a commensal bacterium most commonly associated with the skin exerts such effects locally, modulating local immune responses during inflammation and preventing superinfection by pathogens such as Staphylococcus aureus. Although the prostate is considered by many to be sterile, multiple investigations have shown that small numbers of gram-positive bacterial species such as S. epidermidis can be isolated from the expressed prostatic secretions of both healthy and diseased men. Chronic pelvic pain syndrome is a complex syndrome with symptoms including pain and lower urinary tract dysfunction. It has an unknown etiology and limited effective treatments but is associated with modulation of prostate immune responses. Chronic pelvic pain syndrome can be modeled using murine experimental prostatitis (EAP), where CD4+ve IL17A+ve T cells have been shown to play a critical role in disease orchestration and development of pelvic tactile allodynia. Here, we report that intraurethral instillation of a specific S. epidermidis strain (designated NPI [non-pain inducing]), isolated from the expressed prostatic secretion of a healthy human male, into EAP-treated mice reduced the pelvic tactile allodynia responses and increased CD4+ve IL17A+ve T-cell numbers associated with EAP. Furthermore, a cell wall constituent of NPI, lipoteichoic acid, specifically recapitulates these effects and mediates increased expression of CTLA4-like ligands PDL1 and PDL2 on prostatic CD11b+ve antigen-presenting cells. These results identify a new potential therapeutic role for commensal S. epidermidis NPI lipoteichoic acid in the treatment of prostatitis-associated pain.

Acute lung injury (ALI) is a pathologic condition responsible for incurable human chronic respiratory diseases. Recent studies have shown the involvement of the glycoprotein, IL17A secreted by IL-17 producing cells in chronic inflammation. The current investigation was carried out to study the IL-17A mediated activation of SMAD and non- SMAD signaling in alveolar epithelial cells and to assess the putative modulatory role of curcumin. C57BL/6 mice were exposed to IL-17A and curcumin was administered as an intervention to modulate the IL-17A-induced alveolar damage. Techniques like Immunofluorescence and real-time PCR were used. We found elevated expression of IL-17A and IL-17A-associated signaling pathways to be activated in mice lung tissues. Curcumin intervention in vivo promoted the resolution of IL-17A-induced ALI and attenuated pulmonary damage. Increase phosphorylation of non- SMAD proteins like P-EGFR, P-STAT-1, STAT-3, P-JAK-1/2, P-JNK, and also SMAD proteins like P- SMAD 2/3 and TGF-β1 was encountered upon IL-17A exposure, while curcumin intervention reversed the protein expression levels. Curcumin was found to block mRNA expressions of non- SMAD genes EGFR, JNK-1, JAK1, JAK2, STAT-1, STAT-3, MAPK14, also of TGF-β1 and SMAD genes like SMAD 2, SMAD 3. However, mRNA expressions of SMAD 6 and SMAD 7 were increased upon curcumin intervention. Our study indicates that IL-17A participates in the development of ALI in both SMAD dependent and independent manner and the IL-17A signaling components were effectively controlled by curcumin, suggesting probable anti-inflammatory use of curcumin during ALI.

Keywords: Curcumin; IL-17A; Lung injury; SMAD dependent; SMAD independent.

Interleukin-17-producing T helper cells (Th17) are attracting attention as a new CD4-positive subset of T cells, reported to be responsible for various autoimmune diseases through stimulation of the release of inflammatory cytokines from target cells. However, most investigations of Th17 mediation of autoimmune diseases have focused on the experimental autoimmune models derived from young animals, with few studies that have analyzed physiological factors such as aging. The present study analyzed autoreactive T cells established in a syngeneic mixed lymphocyte culture (sMLC) from aged mice and examined their similarity with Th17. IL-17-producing autoreactive CD4-intermediate T cells were observed in the sMLC; these expressed several stem cell markers or an immunosuppressive receptor PD-1 on the cell surface and so seemed to be different to typical Th17 cells. RT-PCR analysis revealed that purified Th17-like cells also expressed Il17a, Il17f, Il23r, Rorc and Tdt mRNA, but not Rag1 or Rag2 mRNA. These findings that it is likely that Th17-like cells are involved in autoimmune responses in aged mice.

We evaluated the influence of the IL8 T-738A (nonidentified rs), IL8 T-353A (rs4073), IL17A G197A (rs2275913), and IL17F T7488C (rs763780) single-nucleotide polymorphisms on leprosy. The AA genotype of IL8 T-353A was observed as a risk factor for multibacillary leprosy, regardless of gender and age-of-onset of disease, considering the recessive model (OR, 3.8; 95% CI, 1.1-13.5; P, 0.023). Furthermore, the AA genotype of IL17A G197A was associated with leprosy type 1 reaction (OR, 2.4; 95% CI, 1.1-5.1; P, 0.026) when compared to the group without reaction, which was adjusted for gender and age-of-onset of disease by the model log additive. These results indicate association of IL8 and IL17A polymorphisms with the progression to multibacillary leprosy and with the type 1 reaction, respectively.

Objective: To assess the prevalence of axial articular manifestations (AAMs) in primary Sjögren's syndrome (pSS) patients; to investigate whether these symptoms do reveal an associated spondyloarthritis (SpA); and to assess their therapeutic management.

Methods: Among 148 consecutive pSS patients fulfilling ACR/EULAR classification criteria followed between 2010 and 2018, we selected those who presented with AAMs. The association with SpA was retained when patients fulfilled ASAS criteria.

Results: A total of 29 patients (20%, 28 women), median age of 43 years (range: 15-65), were identified. The main extra-glandular features were peripheral arthralgia and arthritis in 93% and 90%, respectively. Positive anti-SSA antibody was reported in 62%. AAMs were inaugural in 7%, delayed from the diagnostic of pSS in 7%, and occurred concomitantly in 86% of patients. AAMs were not associated to pluri-systemic involvement of pSS. Radiological sacroiliitis was mentioned in 65%, and HLA-B27 was positive in 13%. The diagnosis of SpA was retained in 23/29 patients (79%), among which 74% and 26% fulfilled psoriatic arthritis and ankylosing spondylitis criteria, respectively. There was no phenotypic difference according to the anti-SSA antibody status. With a median follow-up of 60 months (range: 5-96), 61% of patients with associated SpA required biotherapies, mainly of anti-TNF-⍺ or anti-IL17A molecules with a good clinical outcome in 64% and no effect on pSS.

Conclusion: AAMs are not uncommon in pSS patients and may reveal an associated SpA. Treatment of AAMs, especially when clearly associated with SpA, may necessitate biologicals following SpA-management therapeutic guidelines.

Colorectal cancer (CRC) is the third leading cause of cancer-associated mortality. The present study aimed to investigate novel biomarkers to predict prognosis and provide a theoretical basis for studies of the pathogenesis and the development of therapies for CRC. The present study compared mRNA expression levels of patients with CRC with short- and long-term prognosis and of individuals with and without tumors in The Cancer Genome Atlas (TCGA) database. Differentially expressed genes (DEGs) were identified via volcano plot and Venn diagram analysis. Gene Ontology (GO) analysis and gene set enrichment analysis (GSEA) were performed to identify the functions of the DEGs, and the DEGs were further verified using clinical CRC samples. A total of 10 DEGs were identified as candidate genes using the TCGA database, and four DEGs [defensin β 4A (DEFB4A), hyaluronan binding protein 2 (HABP2), oleoyl-ACP hydrolase and TBC1 domain family member 3G] were associated with poor prognosis of patients with CRC. Two DEGs (DEFB4A and HABP2) were upregulated in tumor tissues of patients with CRC in the TCGA database. GO and GSEA analyses revealed that DEFB4A was highly associated with immunosuppression, participates in 'myeloid leukocyte differentiation', 'leukocyte proliferation' and 'positive regulation of leukocyte-mediated immunity', and was positively correlated with CD11b, CD14, CD45, CD163 and IL17A. Furthermore, DEFB4A expression was significantly upregulated in patients with large tumors, advanced cancer stage, lymph node metastasis and liver metastasis. Survival analysis revealed that DEFB4A upregulation was associated with poor prognosis. DEFB4A gene knockdown experiments demonstrated that DEF4BA promotes cell migration. These results indicated that DEFB4A potentially promotes tumor growth by regulating immunosuppressive activity and provided novel insights into the diagnosis and treatment of CRC.

Keywords: biomarker; colorectal cancer; defensin β 4A; immunity; prognosis.

Recognition of Ab-opsonized pathogens by immune cells triggers both TLR and Fc receptor signaling. Fc receptors endocytose modified nucleic acids bound to Abs and deliver them to endosomes, where they are recognized by nucleic acid-sensing TLRs (NA-TLRs). We show that in CD4+ T cells, NA-TLRs, TLR3, TLR8, and TLR9 are upregulated by FcγRIIIa-pSyk cosignaling and localize with FcγRIIIa on the cell surface. TLR9 accumulates on the cell surface, where it recognizes CpG oligonucleotide 2006. Subcellular location of NA-TLRs is a key determinant in discriminating self versus viral nucleic acid. Hydroxychloroquine used for treating systemic lupus erythematosus and a Syk inhibitor blocked NA-TLR localization with FcγRIIIa. Engaging TLR9 with CpG oligonucleotide contributes to the development of IL17A+ and IL-21+ populations. RNA-sequencing analysis showed upregulation of proinflammatory cytokines, NF-κB signaling, and heat shock protein pathway RNA transcripts. These data suggest a role for FcγRIIIa-pSyk cosignaling in modulating NA-TLR responses in human CD4+ T cells by affecting the amounts and cellular distribution. These events are important for understanding of autoimmune pathology.

The short isoform of human TIAM2 has been shown to promote proliferation and invasion in various cancer cells. However, the roles of TIAM2S in immune cells in relation to tumor development have not been investigated. To characterize the effects of TIAM2S, we generated TIAM2S-overexpressing mouse lines and found that aged TIAM2S-transgenic (TIAM2S-TG) developed significantly higher occurrence of lymphocytic infiltration and tumorigenesis in various organs, including colon. In addition, TIAM2S-TG is more sensitized to AOM-induced colon tumor development, suggesting a priming effect toward tumorigenesis. In the light of our recent findings that TIAM2S functions as a novel regulator of cellular serotonin level, we found that serotonin, in addition to Cox2, is a unique inflammation marker presented in the colonic lesion sites in the aged TG animals. Furthermore, our results demonstrated that ectopic TIAM2S altered immunity via the expansion of T lymphocytes; this was especially pronounced in CD8⁺ T cells in combination with CXCL13/BCA-1 pro-inflammatory chemokine in the serum of TIAM2S-TG mice. Consequently, T lymphocytes and B cells were recruited to the lesion sites and stimulated IL-23/IL17A expression to form the tertiary lymphoid organs. Collectively, our research suggests that TIAM2S provokes a pro-inflammatory immune microenvironment permissive to colorectal tumorigenesis through the serotonin-induced immunomodulatory effects.

Keywords: T lymphocyte; T-cell lymphoma invasion and metastasis 2; chronic inflammation; inflammatory bowel disease; serotonin.

In leporids, IL17A had been implicated in the host defense against extracellular pathogens, such as Francisella tularensis that infects hares and rabbits and causes the zoonotic disease tularemia. Here, we studied IL17A from five lagomorphs, European rabbit, pygmy rabbit, brush rabbit, European brown hare, and American pika. We observed that this protein is highly conserved between these species, with a similarity of 97-99% in leporids and ~88% between leporids and American pika. The exon/intron structure, N-glycosylation sites, and cysteine residues are conserved between lagomorphs. However, at codon 88, one of the interaction sites between IL17A and its receptor IL17RA, there is an Arg>Pro mutation that only occurs in European rabbit and European brown hare. This could induce critical alterations in the IL17A structure and conformation and consequently modify its function. The differences observed between leporids and humans or rodents might also represent important alterations in protein structure and function. In addition, as for other interleukins, IL17A sequences of human and European rabbit are more closely related than the sequences of human and mouse or European rabbit and mouse. This study gives further support to the hypothesis that European rabbit might be a more suitable animal model for studies on human IL17.