Targeting human CD2 by the monoclonal antibody CB.219 reduces intestinal inflammation in a humanized transfer colitis model

Identification and validation of hub genes expressed in ulcerative colitis with metabolic dysfunction-associated steatotic liver disease

Objective

Ulcerative colitis (UC) and metabolic dysfunction-associated steatotic liver disease (MASLD) are closely intertwined; however, the precise molecular mechanisms governing their coexistence remain unclear.

Methods

We obtained UC (GSE75214) and MASLD (GSE151158) datasets from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were acquired by the 'edgeR' and 'limma' packages of R. We then performed functional enrichment analysis of common DEGs. Hub genes were selected using the cytoHubba plugin and validated using GSE87466 for UC and GSE33814 for MASLD. Immunohistochemistry was employed to validate the hub genes' expression in clinical samples. Immune infiltration and gene set enrichment analyses of the hub genes were performed. Finally, we estimated the Spearman's correlation coefficients for the clinical correlation of the core genes.

Results

Within a cohort of 26 differentially regulated genes in both UC and MASLD, pathways involving cytokine-mediated signaling, cell chemotaxis, and leukocyte migration were enriched. After further validation, CXCR4, THY1, CCL20, and CD2 were identified as the hub genes. Analysis of immune infiltration patterns highlighted an association between elevated pivotal gene expression and M1 macrophage activation. Immunohistochemical staining revealed widespread expression of pivotal genes in UC- and MASLD-affected tissues. Furthermore, significant correlations were observed between the increased expression of hub genes and biochemical markers, such as albumin and prothrombin time.

Conclusion

This bioinformatics analysis highlights CXCR4, THY1, CCL20, and CD2 as crucial genes involved in the co-occurrence of UC and MASLD, providing insights into the underlying mechanisms of these two conditions.

Visualization of Inflammation in Experimental Colitis by Magnetic Resonance Imaging Using Very Small Superparamagnetic Iron Oxide Particles

Inflammatory bowel diseases (IBD) comprise mainly ulcerative colitis (UC) and Crohn´s disease (CD). Both forms present with a chronic inflammation of the (gastro) intestinal tract, which induces excessive changes in the composition of the associated extracellular matrix (ECM). In UC, the inflammation is limited to the colon, whereas it can occur throughout the entire gastrointestinal tract in CD. Tools for early diagnosis of IBD are still very limited and highly invasive and measures for standardized evaluation of structural changes are scarce. To investigate an efficient non-invasive way of diagnosing intestinal inflammation and early changes of the ECM, very small superparamagnetic iron oxide nanoparticles (VSOPs) in magnetic resonance imaging (MRI) were applied in two mouse models of experimental colitis: the dextran sulfate sodium (DSS)-induced colitis and the transfer model of colitis. For further validation of ECM changes and inflammation, tissue sections were analyzed by immunohistochemistry. For in depth ex-vivo investigation of VSOPs localization within the tissue, Europium-doped VSOPs served to visualize the contrast agent by imaging mass cytometry (IMC). VSOPs accumulation in the inflamed colon wall of DSS-induced colitis mice was visualized in T₂* weighted MRI scans. Components of the ECM, especially the hyaluronic acid content, were found to influence VSOPs binding. Using IMC, co-localization of VSOPs with macrophages and endothelial cells in colon tissue was shown. In contrast to the DSS model, colonic inflammation could not be visualized with VSOP-enhanced MRI in transfer colitis. VSOPs present a potential contrast agent for contrast-enhanced MRI to detect intestinal inflammation in mice at an early stage and in a less invasive manner depending on hyaluronic acid content.

Dysregulated lncRNAs are Involved in the Progress of Sepsis by Constructing Regulatory Networks in Whole Blood Cells

Sepsis is a highly heterogeneous syndrome that is caused by an unbalanced host response to an infection. Long noncoding RNAs (lncRNAs) have been reported to exert regulatory roles in a variety of biological processes, and became potential biomarkers and therapeutic targets for diverse diseases. However, current understanding on the roles of lncRNAs in sepsis is extremely limited. Herein, to decipher the underlying functions of lncRNAs, we reexplored the 83 transcriptome datasets from specimens with sepsis, no_sepsis by final diagnosis, and control. The results of differentially expressed genes (DEGs), differentially expressed lncRNA (DElncRNA) analysis, and co-expression analysis of lncRNA–mRNA pairs were obtained. We found that the expression pattern of lncRNAs was significantly activated in sepsis specimens, which was clearly distinguished in sepsis from no_sepsis and control specimens. By performing co-expression analysis, we found DElncRNAs were closely related to T-cell activation and immune response–related terms in sepsis by regulating mRNA expression in the trans manner. The lncRNA–mRNA network and the qRT-PCR test revealed that lncRNAs LINC00861, RP11-284N8.3, and CTB-61M7.2 were significantly correlated with the pathogenesis of sepsis. In addition, weighted gene co-expression analysis (WGCNA) and cis-regulation analysis also revealed sepsis-specific lncRNAs were highly associated with important biological processes correlated with sepsis. In summary, the systematic dysregulation of lncRNAs is tightly involved in the remodeling of gene expression regulatory network in sepsis, and the lncRNA–mRNA expression network may be used to refine biomarker predictions for developing novel therapeutic approaches in sepsis.

CD2 Immunobiology

The glycoprotein CD2 is a costimulatory receptor expressed mainly on T and NK cells that binds to LFA3, a cell surface protein expressed on e.g., antigen-presenting cells. CD2 has an important role in the formation and organization of the immunological synapse that is formed between T cells and antigen-presenting cells upon cell-cell conjugation and associated intracellular signaling. CD2 expression is upregulated on memory T cells as well as activated T cells and plays an important role in activation of memory T cells despite the coexistence of several other costimulatory pathways. Anti-CD2 monoclonal antibodies have been shown to induce immune modulatory effects in vitro and clinical studies have proven the safety and efficacy of CD2-targeting biologics. Investigators have highlighted that the lack of attention to the CD2/LFA3 costimulatory pathway is a missed opportunity. Overall, CD2 is an attractive target for monoclonal antibodies intended for treatment of pathologies characterized by undesired T cell activation and offers an avenue to more selectively target memory T cells while favoring immune regulation.

Anti-inflammatory effects of Dioscorea alata L. anthocyanins in a TNBS-induced colitis model

The purple yam, Dioscorea alata L., is an important source of starch, vitamins and polyphenols. Five different pigments from the purple tubers of this plant were separated by high-performance liquid chromatography-mass spectrometry, and the anthocyanin fraction (DACN) was collected. The anti-inflammatory effects of DACNs were investigated at different concentrations and compared with the standard colitis treatment, 5-aminosalicylic acid, in a trinitrobenzenesulfonic acid (TNBS)-induced colitis mouse model. Macro- and microscopic parameters including body weight change, disease activity index (DAI) and intestinal histology were used for the determination of the anti-inflammatory effects of DACNs. The gene expression levels of tight junction-related proteins in the intestine, myeloperoxidase activity, inducible nitric oxide synthase activity in colonic tissues and pro-inflammatory cytokine production in serum were also measured to elucidate the mechanism of DACN action. Eighty micrograms of DACNs per kilogram of body weight produced potent anti-inflammatory effects in the mouse model of inflammatory bowel disease (IBD), as shown by the DAI (2.78 ± 0.38 vs. 0.44 ± 0.51). Therefore, DACNs may be applied as a potential food supplement in IBD therapy.

The tyrosine kinase inhibitor tyrphostin AG126 reduces activation of inflammatory cells and increases Foxp3+ regulatory T cells during pathogenesis of rheumatoid arthritis

Protein tyrosine kinases are key mediators of the signal transduction cascades that control expression of many genes involved in the induction of inflammation caused by arthritis. Here we investigate the effect of the tyrosine kinase inhibitor tyrphostin AG126 on a mouse model of adjuvant-induced arthritis (AIA). We report that when given at 5mg/kg i.p. every 48h from days 0-21, AG126 exerts potent anti-arthritic effects. Further, we investigated the role of AG126 on the key mediators of arthritic inflammation, namely, edema, arthritic score, presence of immunophenotypes including Foxp3⁺, CD4⁺Foxp3⁺, and CD25⁺Foxp3⁺ T regulatory (Treg) cells, as well as pro- and anti-inflammatory mediators. AG126 treatment significantly attenuated the severity of AIA and caused a substantial reduction in the percentage of CD2⁺, CD3⁺, CD4⁺, CD8⁺, CD23⁺, CD80⁺, CD86⁺ CD122⁺, CD195⁺, TCRβ⁺, and GITR⁺ cells in whole blood. Moreover, administration of AG126 under arthritis-inducing conditions resulted in suppression of IL-17A⁺, IFN-γ⁺, CD4⁺ and CD25⁺ populations while causing an increase in the Foxp3⁺, CD4⁺Foxp3⁺, and CD25⁺Foxp3⁺ Treg populations in the spleen. In addition, RT-PCR analysis revealed increased expression of CD4, CD8, IL-17A, IFN-γ, TNF-α, and NF-κB p65 mRNAs and decreased IL-4 mRNA in the arthritic control (AC) mice, while treatment of animals with AG126 reversed these effects. Western blot analysis confirmed the decreased expression of IL-17, GITR, NF-κB p65 proteins and increased Foxp3 and IL-4 proteins following AG126 treatment of knee tissue. Thus, our findings provide new evidence that inhibition of protein tyrosine kinase activity decreases the progression of arthritis.

Preventive Anti-CD2 Treatment does not Impair Parasite Control in a Murine Toxoplasmosis Model

Targeting human CD2 with the monoclonal antibody (mAb) CB.219 reduces intestinal inflammation in a colitis model where T cells carry human CD2. Here, we asked whether this mAb has adverse effects on infection control.

Mice expressing human CD2 on T cells (huCD2tg) were orally infected with Toxoplasma (T.) gondii and treated with the human CD2-specific mAb CB.219 in a preventive setting. The intestinal T. gondii loads in CB.219 treated mice did not differ from the control group. Histologically, huCD2tg mice showed moderate ileal inflammation that did not change with CB.219 treatment. In the ileum, CB.219 treatment reduced the protein levels of interferon-γ, transforming growth factor β and interleukin-6, whereas interleukin-18 mRNA was slightly increased. The infiltration of neutrophils, macrophages, and T cells into the ileum was unaffected by CB.219 treatment. However, CB.219 treatment decreased the numbers of forkhead box P3⁺ regulatory T cells (Treg) in ileum and liver of huCD2tg mice. This was confirmed in vitro using human peripheral blood mononuclear cells.

Taken together, targeting CD2⁺ T cells by the human CD2 mAb CB.219 does not prevent beneficial immune reactions necessary for pathogen control. Further experiments will address gut specificity, underlying mechanisms, and general applicability of CB.219 treatment.