Lectins are proteins responsible for recognizing the signals of sugar molecules in the body. Sialic acid-binding immunoglobulin-like lectins (Siglecs) regulate the innate and adaptive immune responses in the tumor microenvironment by recognizing the glycan structure containing sialic acid and mediating downstream signals through immune receptor tyrosine inhibitory motifs. In recent years, a variety of tumor treatment strategies targeting the sialic acid-Siglecs axis have been introduced, including sialoglycoprotein-mediated drug delivery and antibody mediated inhibition of Siglecs from recognizing tumor surface ligands. In the future, by combining with glycoprotein nanotherapy, antibody therapy and gene therapy, Siglecs can be used to accurately locate tumor targets and release the anti-tumor immunity, so as to achieve the purpose of effective cure of tumors.
Sialic Acid Binding Immunoglobulin-like Lectins/metabolism* ; N-Acetylneuraminic Acid ; Immunoglobulins/metabolism* ; Receptors, Immunologic ; Ligands

Objective: To investigate the effect of CD33-targeted bi-specific and tri-specific T-cell engagers on T-cell proliferation and explore their cytotoxicity on leukemia cells. Methods: The CD33-targeted bi-specific T-cell engager (CD33-BiTE) and tri-specific T-cell engager (CD33-TriTE) expression vectors were successfully constructed and expressed through a eukaryotic cell expression system. CD33-BiTE and CD33-TriTE were purified by affinity chromatography. The effects of CD33-BiTE and CD33-TriTE on T cells were analyzed through in vitro experiments. Results: ① CD33-BiTE and CD33-TriTE were successfully constructed and purified and could compete with flow cytometry antibodies for binding to the target cells. ② After 12 days of co-culture with CD33-BiTE and CD33-TriTE, the number of human T cells were expanded to 33.89±19.46 and 81.56±23.62 folds, respectively. CD33-TriTE induced a stronger proliferation of T cells than CD33-BiTE (P<0.05) . ③ Both CD33-BiTE and CD33-TriTE induced specific dose-dependent cytotoxicity on CD33(+) leukemia cells. ④ Compared to CD33-TriTE, leukemia cells were prone to express PD-L1 when co-cultured with T cells and CD33-BiTE. CD33-TriTE induced powerful cytotoxicity on leukemia cells with high PD-L1 expression. Conclusion: CD33-BiTE and CD33-TriTE expression vectors were constructed, and fusion proteins were expressed in eukaryotic cells. Our results support the proliferative and activating effects of BiTE and TriTE on T cells. Compared to that of CD33-BiTE, CD33-TriTE induced a stronger proliferative effect on T cells and a more powerful cytotoxicity on leukemia cells with high PD-L1 expression.
B7-H1 Antigen/pharmacology* ; Humans ; Leukemia, Myeloid, Acute/metabolism* ; Sialic Acid Binding Ig-like Lectin 3/pharmacology* ; T-Lymphocytes

OBJECTIVE: To investigate the expressions of CD33 and CD13 in newly diagnosed multiple myeloma (MM) patients and its relationship with prognosis. METHODS: It was retrospectively observed that the expression of CD33 and CD13 in 121 MM patients who were newly diagnosed from January 2014 to January 2020, and the relationship between the expressions of CD33 and CD13 and patients prognosis was analyzed. RESULTS: Among the 121 newly diagnosed MM patients, there were 30 patients (24.8%) in the CD33⁺ group and 12 patients (9.9%) in the CD13⁺ group. Kaplan-Meier analysis showed that, compared with the CD33^- group, the progression-free survival (PFS) time and overall survival (OS) time were significantly shortened in MM patients in CD33⁺ group (PFS 17.5 vs 23 months, P=0.000; OS 18.5 vs 25 months, P=0.000); and the PFS time and OS time of MM patients in the CD13⁺ group were also significantly shortened than those in CD13^- group (PFS 21 vs 22 months, P=0.012; OS 25 vs 26 months, P=0.006). Cox regression analysis showed that CD33 and CD13 were independent adverse prognostic factors in MM patients (CD33: P=0.000;CD13: P=0.003). CONCLUSION CD33 and CD13 are prognostic risk factors in patients with MM.
CD13 Antigens ; Cell Count ; Humans ; Kaplan-Meier Estimate ; Multiple Myeloma ; Prognosis ; Retrospective Studies ; Sialic Acid Binding Ig-like Lectin 3

Chronic obstructive pulmonary disease (COPD) has become the third-leading cause of death worldwide, which is a severe economic burden to the healthcare system. Chronic bronchitis is the most common condition that contributes to COPD, both locally and systemically. Neutrophilic inflammation predominates in the COPD airway wall and lumen. Logically, repression of neutrophilia is an essential fashion to COPD treatment. However, currently available anti-neutrophilic therapies provide little benefit in COPD patients and may have serious side effects. Thus, there is an urgent need to explore an effective and safe anti-neutrophilic approach that might delay progression of the disease. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 is a member of the Siglec cell surface immunoglobulin family. It is noteworthy that Siglec-9 is highly expressed on human neutrophils and monocytes. Ligation of Siglec-9 by chemical compounds or synthetic ligands induced apoptosis and autophagic-like cell death in human neutrophils. Furthermore, administration of antibody to Siglec-E, mouse functional ortholog of Siglec-9, restrained recruitment and activation of neutrophils in mouse models of airway inflammation in vivo. Given the critical role that neutrophils play in chronic bronchitis and emphysema, targeting Siglec-9 could be beneficial for the treatment of COPD, asthma, fibrosis, and related chronic inflammatory lung diseases.
Animals ; Asthma ; Humans ; Lung ; Mice ; N-Acetylneuraminic Acid ; Neutrophils ; Pulmonary Disease, Chronic Obstructive/drug therapy* ; Sialic Acid Binding Immunoglobulin-like Lectins

Carcinoma, Renal Cell ; Disease Progression ; Humans ; Immunoglobulins/genetics* ; Kidney Neoplasms ; Membrane Proteins/genetics* ; Sialic Acid Binding Immunoglobulin-like Lectins

Antigens, CD19 ; Automobiles ; Cytokine Release Syndrome/complications* ; Humans ; Immunotherapy, Adoptive ; Leukemia, B-Cell/complications* ; Receptors, Antigen, T-Cell ; Sialic Acid Binding Ig-like Lectin 2 ; T-Lymphocytes

OBJECTIVE: To explore the therapeutic effect of Fasudil-modified splenic mononuclear cells (MNCs) in experimental autoimmune encephalomyelitis (EAE) and the possible mechanisms.
 METHODS: C57BL/6 female mice were immunized with myelin oligodendrocyte glycoprotein peptide 35-55 to establish active immunity EAE model. Splenic MNCs were isolated on the 9th day after immunization and treated with or without Fasudil for 72 h in vitro. These cells were collected for analysis of the variance of T cell subtypes, the level of cytokines and the activity of Rho kinase (ROCK). MNCs (5×107 cells) were resuspended in 500 µL of phosphate buffer solution (PBS) and transferred into EAE model (intraperitoneal injection), which was divided into a PBS-MNCs group and a Fasudil-MNCs group. Changes of body weight and clinical symptom scores were observed.
 RESULTS: Splenic encephalitogenic MNCs from EAE mice on the 9th day after immunization could establish passive transfer EAE model. But Fasudil-treated MNCs did not trigger EAE development. Compared with the PBS-MNCs group, the loss of body weight was less in the Fasudil-MNCs group. The in vitro experiment indicated that Fasudil could suppress the activity of ROCK on MNCs (P<0.01), decrease the percentage of CD4+ T cells with the expression of interferon-γ (IFN-γ) and interleukin-17 (IL-17) (IFN-γ: P<0.01; IL-17: P<0.05), while increase the secretion of CD4+ T cells with the expression of transforming growth factor-β (TGF-β) and IL-10 (all P<0.001) . Furthermore, Fasudil could inhibit the release of IL-17 (P<0.001) and enhance the level of IL-10 (P<0.05).
 CONCLUSION Fasudil-modified cell therapy affects the occurrence and development of EAE by inhibiting the inflammatory reaction of helper T cell 1 (Th1) and Th17 while enhancing the immunoregulative effect of Th2.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine ; analogs & derivatives ; Animals ; Encephalomyelitis, Autoimmune, Experimental ; Female ; Interferon-gamma ; Interleukin-10 ; Interleukin-17 ; Mice ; Mice, Inbred C57BL ; Myelin-Oligodendrocyte Glycoprotein ; Spleen ; T-Lymphocytes ; Transforming Growth Factor beta ; rho-Associated Kinases

CD22 is a type I transmembrane protein expressed on most mature B lymphocyte, and plays a significant role in signal transduction pathways. CD22 acts as a co-receptor of the B-cell receptor (BCR) that inhibits the BCR signaling by antigen-receptor interaction. The phosphorylation of CD22 can be triggered by cross-linking of CD22 with the BCR through antigen, then predominantly triggers the dephosphorylation and inactivation of downstream proteins and inhibit the BCR signaling. Autoimmune disease could be caused by the abnormal expression or dysfunction of CD22 which interrupts BCR signaling and then influences the quantity and function of B cells. The further study of the function and regulation of CD22 would help us understanding the pathogenesis of autoimmune disease and setting theoretical basis for its targeting treatment. In this article, the structure and expression of CD22, the ligands of CD22, the regulation of BCR and transmenbrane signaling, the effect of CD22 on B cells, and CD22 and autoimmune diseases were reviewed.
Autoimmune Diseases ; B-Lymphocytes ; Humans ; Phosphorylation ; Receptors, Antigen, B-Cell ; Sialic Acid Binding Ig-like Lectin 2 ; Signal Transduction

This study was aimed to investigate clinical and prognostic significances of 4 target antigens (CD19, CD20, CD22 and CD33) for antibody-based immunotherapy and to evaluate the applications of these antibody-based target therapy to adult acute lymphoblastic leukemia (ALL). The immunophenotype of 220 adult patients with ALL were analyzed by four-color flow Cytometry, and cytogenetic and molecular parameters were detected by conventional cytogenetics, fluorescence in situ hybridization, real-time quantitative PCR, nested PCR and DNA sequencing. The results showed that CD19 positive (CD19(+)) cases were more in female (46.4% vs. 23.4%, P = 0.006), elderly patients aged > 60 years (14.4% vs. 2.1%, P = 0.022), CD33(+) co-expression cases (47.8% vs. 12.0%, P = 0.001) and genetic high-risk group (55.8% vs. 20.8%, P = 0.002) compared with CD19 negative (CD19(-)) cases; CD20(+) cases had lower co-expression of CD13 than CD20(-) cases (31.6% vs.67.1%, P = 0.000) and no significant prognostic indications for CD20(+) was observed; CD22(+) cases had higher relapse rate at 12-month than CD22(-) cases (93.9% vs.57.1%, P = 0.041) in B-ALL patients; CD33(+) cases had higher incidence of Ph(+) than CD33(-) cases (43.5% vs.19.4%, P = 0.007) and significantly correlated with Ph(+) (r = 0.261, P = 0.006). It is concluded that elucidation of the characteristics of the target antigens (CD19, CD20, CD22, CD33) used for antibody-based immunotherapy will help hematologists making the correct decision whether and when to use these antibody-based target therapies.
Adolescent ; Adult ; Aged ; Antigens, CD19 ; immunology ; Antigens, CD20 ; immunology ; Child ; Female ; Humans ; Immunophenotyping ; Male ; Middle Aged ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; immunology ; Sialic Acid Binding Ig-like Lectin 2 ; immunology ; Sialic Acid Binding Ig-like Lectin 3 ; immunology ; Young Adult

OBJECTIVETo investigate the expression of CD33⁺ HLA-DR⁻ myeloid-derived suppressor cells (MDSCs) in the peripheral blood of patients with renal carcinoma and its correlation with the clinicopathological features of renal cancer.

METHODSForty-four patients with renal carcinoma treated in our hospital between June, 2011 and October, 2012 and 18 healthy volunteers were enrolled in this study. Flow cytometry was performed to detect CD33⁺ HLA-DR⁻ MDSCs in the peripheral blood, and its correlation with the clinicopathological features of the patients were analyzed.

RESULTSThe positivity rate of CD33⁺ HLA-DR⁻ MDSCs in the peripheral blood was significantly higher in the cancer patients than in the healthy controls [(1.91 ± 0.66)% vs (0.62 ± 0.22)%, P<0.001]. The expression levels of CD33⁺ HLA-DR⁻ MDSCs in patients with renal carcinoma showed significant differences between stage I+II [(1.46 ± 0.44)%] and stage III [(2.04 ± 0.35)%] patients (P<0.01) and between stage III and stage IV patients [(2.50 ± 0.64)%] (P<0.05), but did not differ significantly in respect of age or gender.

CONCLUSIONCD33⁺ HLA-DR⁻ MDSCs expression in the peripheral blood is associated with tumor stage and differentiation in renal carcinoma and may play an important role in predicting the prognosis and tumor immunology of renal carcinoma.

Adult ; Aged ; Case-Control Studies ; Female ; Flow Cytometry ; HLA-DR Antigens ; metabolism ; Humans ; Immunophenotyping ; Kidney Neoplasms ; blood ; immunology ; Male ; Middle Aged ; Myeloid Cells ; cytology ; metabolism ; Neoplasm Staging ; Prognosis ; Sialic Acid Binding Ig-like Lectin 3 ; metabolism ; Young Adult