Objective To screen the anti-CD22-specific nanobodies to provide a basis for immunotherapy agents. Methods The naive phage nanobody library was constructed and its diversity was analyzed. Three rounds of biotinylated streptavidin liquid phase screening were performed by using biotinylated CD22 antigen as the target, and the sequence of nanobodies against CD22 were identified by ELISA and gene sequencing. Results The capacity of the constructed naive phage nanobody library was 3.89×10⁹ CFU/mL, and the insertion of effective fragments was higher than 85%. Based on this library, seven anti-human CD22 nanobodies were screened, and the amino acid sequence comparison results showed that the overall similarity was 70.34%, and all of them were hydrophilic proteins. The results of protein-protein complex docking prediction showed that the mimetic proteins of the five nanobody sequences could be paired and linked to CD22, and the main forces were hydrophobic interaction and hydrogen bonding. Conclusion This study provided a basis for the study of chimeric antigen receptor T cells targeting CD22, successfully constructed the natural phage nanobody library and obtaining five anti-CD22-specific nanobodies.
Camelus/immunology* ; Single-Domain Antibodies/chemistry* ; Peptide Library ; Humans ; Animals ; Sialic Acid Binding Ig-like Lectin 2/genetics* ; Amino Acid Sequence ; Molecular Docking Simulation

Objective To explore the expression levels of CD33⁺ myeloid-derived suppressor cell (MDSC)-mediated T lymphocyte function and related inflammatory factors secreted by T lymphocyte subsets in patients with cervical cancer, and to analyze their correlation with the treatment efficacy of ¹²⁵I particle implantation combined with arterial chemoembolization, as well as predictive value for treatment outcomes and interaction effects. Methods From January 1st, 2021 to January 1st, 2024, our hospital admitted 152 patients with advanced cervical cancer, who were confirmed by pathological examination. All patients received uterine artery chemoembolization combined with ¹²⁵I particle implantation. The predictive value of CD33⁺MDSC levels for clinical treatment response in cervical cancer was assessed using receiver operating characteristic (ROC) curve analysis. Multivariate logistic regression analysis was performed to evaluate both multiplicative and additive interactions between CD33⁺MDSC and T lymphocytes in predicting clinical treatment failure of cervical cancer. Kaplan Meier method was used to analyze the survival differences between cervical cancer patients with high and low CD33⁺MDSC expression levels. Results Compared with the effective group, patients in the ineffective group had decreased expression levels of CD3⁺ T lymphocyte, CD4⁺ T lymphocyte, interleukin 2 (IL-2) and interferon γ (IFN-γ), while showing increased expression levels of CD33⁺MDSC, CD8⁺ T lymphocyte, IL-4 and IL-6, along with increased tumor necrosis factor α (TNF-α) levels, larger maximum tumor diameters, and a higher incidence of lymph node metastasis. The expression levels of CD33⁺MDSCs demonstrated good predictive performance for treatment efficacy in cervical cancer patients. The high CD33⁺MDSC expression group had a significantly shorter overall survival (OS) than the low CD33⁺MDSC expression group (6.0±1.0 months vs. 12.0±1.2 months; t=33.280). The interaction analysis revealed that CD33⁺MDSCs and CD8⁺ T lymphocytes were highly expressed, while CD3⁺ and CD4⁺ T lymphocytes were lowly expressed, which was associated with an increased risk of clinical treatment failure in cervical cancer patients. Conclusion CD33⁺MDSCs can inhibit CD3⁺ and CD4⁺ T lymphocytes. It can upregulate the expression of CD8⁺ T lymphocytes, form an immunosuppressive microenvironment, and reduce the treatment response rate of ¹²⁵I particle implantation combined with arterial chemoembolization. CD33⁺MDSCs may serve as an independent biomarker for predicting the therapeutic efficacy and poor prognosis.
Humans ; Female ; Uterine Cervical Neoplasms/immunology* ; Middle Aged ; Chemoembolization, Therapeutic/methods* ; Sialic Acid Binding Ig-like Lectin 3/immunology* ; Adult ; T-Lymphocytes/immunology* ; Aged ; Treatment Outcome

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 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

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

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

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

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