Preclinical development of a novel CCR8/CTLA-4 bispecific antibody for cancer treatment by disrupting CTLA-4 signaling on CD8 T cells and specifically depleting tumor-resident Tregs.

Anti-CTLA-4 antibodies faced challenges due to frequent adverse events and limited efficacy, which spurred the exploration of next-generation CTLA-4 therapeutics to balance regulatory T cells (Tregs) depletion and CD8 T cells activation. CCR8, identified primarily on tumor-infiltrating Tregs, has become a target of interest due to the anti-tumor effects demonstrated by CCR8 antibody-mediated Tregs depletion. Single-cell RNA sequencing analysis reveals that CCR8-positive Tregs constitute a small subset, with concurrent expression of CCR8 and CTLA-4. Consequently, we proposed a novel bispecific antibody targeting CCR8 and CTLA-4 that had the potential to enhance T cell activation while selectively depleting intratumor Tregs. The candidate molecule 2MW4691 was developed in a tetravalent symmetric format, maintaining a strong binding affinity for CCR8 while exhibiting relatively weaker CTLA-4 binding. This selective binding ability allowed 2MW4691 to target and deplete tumor-infiltrating Tregs with higher specificity. In vitro assays verified the antibody's capacity for antibody-dependent cellular cytotoxicity (ADCC) to Tregs with high level of CTLA-4 expression, but not CD8 T cells with relatively low level of CTLA-4 on cell surface. Also, 2MW4691 inhibited the CTLA-4 pathway and enhanced T cell activation. The in vivo therapeutic efficacy of 2MW4691 was further demonstrated using hCCR8 or hCTLA-4 humanized mouse models and hCCR8/hCTLA-4 double knock-in mouse models. In cynomolgus monkeys, 2MW4691 was well-tolerated, exhibited the anticipated pharmacokinetic profile, and had a minimal impact on the peripheral T cell population. The promising preclinical results supported the further evaluation of 2MW4691 as a next-generation Treg-based therapeutics in clinical trials.

Study on diagnosis and management strategies on heterotopic pregnancy: a retrospective study.

Heterotopic pregnancy (HP) is a rare but potentially life-threatening event with a high risk of maternal death, which also jeopardise the coexisting intrauterine pregnancy (IUP), thus an early accurate diagnosis and prompt treatment can decrease adverse complications. We aimed to explore the early predictors for pregnancy outcomes of HP. We reviewed patients with HP following assisted reproductive technology in our institution between January 2013 and December 2020. The relationships between pregnancy outcomes and clinical features were analysed by logistic regression. We found that 29 patients (72.5%) of HP were accurately diagnosed by transvaginal ultrasonography (TVS). Eighteen patients in the surgery group had live births, three of whom delivered preterm. Additionally, the miscarriage rate was lower for patients with IUP cardiac activity than those without (16.7% vs. 90.0%, p < .001). Further by logistic regression analysis, an IUP with cardiac activity at HP diagnosis was identified as favourable independent predictor of live birth (p < .001). Therefore, early diagnosis and prompt surgical intervention are recommended to prevent the development of HP.Impact of statementWhat is already known on this subject? Heterotopic pregnancy (HP) has long been thought to be a rare but potentially life-threatening event with a high risk of complications. The early diagnosis of HP is challenging due to the co-existence of a viable intrauterine pregnancy (IUP) and the absence of typical clinical symptoms.What do the results of this study add? This stduy showed that symptoms combined with routine transvaginal ultrasonography (TVS) scans reduce the rates of misdiagnosis of HP and prompt surgical intervention after diagnosis may minimise the incidence of miscarriage of the IUP.What are the implications of these findings for clinical practice and/or further research? An IUP with cardiac activity at HP diagnosis is a predictor of a favourable prognosis of HP, and laparoscopy under general anaesthesia is effective and safe during the first trimester of pregnancy. Awareness, assessment and early interventions in view of symptoms combined with routine TVS is recommended to reduce the risk of miscarriage and ensure a favourable live birth rate.

Associations of MCM8 rs3761873 and rs16991617 variants with abnormal uterine bleeding induced by copper intrauterine device.

AIM: Intrauterine device (IUD) is a commonly used contraceptive method worldwide. Abnormal uterine bleeding (AUB) is one of the most common side effects of Cu-IUDs. Since AUB varies among Cu-IUD users, changes in the bleeding-related genetic factors may contribute to AUB. This study aimed to determine the genetic risk factors of AUB after Cu-IUD insertion. METHODS: We conducted a case-control study on women who experienced AUB after Cu-IUD insertion (case:control = 62:59). Six candidate variants were genotyped using the Sequenom MassARRAY. Genotype and allele frequencies were analyzed using SHEsisPlus. We performed Pearson's Chi-squared test to analyze categorical data, and ESEfinder to predict the impact on splicing regulation. RESULTS: MCM8 coding sequence variants: rs3761873-A>C was in Exon 7 and rs16991617 A>G was in Exon 12 of all 19 exons, both of which were significantly different between cases and controls (pallele  = 0.039 and pgenotype  = 0.092). rs6022 and rs6029 in F5 gene and rs3761873 and rs16991617 in the MCM8 gene showed strong linkage disequilibrium (R2 > 0.8). ESEfinder indicated that the variants of MCM8 may affect the splicing regulation. CONCLUSIONS: MCM8 rs376187 and rs16991617 were associated with AUB in Cu-IUDs users. MCM8 may play a role in AUB by regulating functions of reproductive organs and primary ovarian insufficiency. Our findings may improve the understanding of the genetic basis of AUB caused by Cu-IUDs.

Whole-exome sequencing reveals novel variants associated with abnormal uterine bleeding caused by copper intrauterine device.

Aim: This study aimed to explore the genetic risk factors and validate variants of abnormal uterine bleeding after copper intrauterine device insertion. Methods: Whole-exome sequencing was performed and several variants were validated by Sequenom MassARRAY. Results: Eight variants showed potential clinical damage according to American College of Medical Genetics and Genomics criteria. By combined analysis of screening and validation, NFASC RS2802808 C>G p.Ile971Met (Pallele = 0.009 and Pgenotype = 0.027) and PIGR RS2275531 C>T p.Gly365Ser (Pallele = 0.009 and Pgenotype = 0.013) variants were identified as significantly associated with abnormal uterine bleeding with a false discovery rate <0.05. NFASC and PIGR may play a role in abnormal uterine bleeding by regulating coagulation fibrinolysis and endometrial epithelium inflammation functions. Conclusion: These findings provide a genetic basis for clinical individualization and precision of intrauterine device implantation.

Abnormal uterine bleeding (AUB) after Cu intrauterine device (Cu-IUD) insertion is the most common side effect of Cu-IUD use. AUB is a multifactorial process that relates to endometrial-related genetic factors, ovulatory function-related genetic factors, coagulation, the fibrinolytic system, contraction of the uterine arteries and endometritis inflammatory factor. This is the first study to explore the underlying genetic mechanisms of AUB related to the use of Cu-IUDs by whole-exome sequencing in the Chinese Han population. The authors found that variants of NFASC and PIGR genes were significantly associated with AUB in women using Cu-IUDs. NFASC and PIGR may be involved in coagulation fibrinolysis and endometrial epithelium inflammation functions, indicating its potential functions in AUB. This study could provide a genetic basis for studies on the individualization and precision of IUD use in the future.

Tandem mass tag-based quantitative proteomic profiling of the serum of patients with abnormal uterine bleeding associated with copper intrauterine device.

OBJECTIVE: To investigate changes in the level of protein in serum and uncover the underlying pathogenesis of abnormal uterine bleeding (AUB) associated with copper intrauterine devices (Cu IUD). METHODS: Protein profiles were investigated via tandem mass tag (TMT)-based quantitative proteomics and bioinformatics technology. Quantification and characterization of candidate proteins were further performed in 33 controls and 45 cases by Luminex assay and enzyme-linked immunosorbent assay. RESULTS: In total, 842 proteins were identified via TMT coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the serum of individuals with IUDs. Among them, 25 differentially expressed proteins (p < 0.05) were observed, including eight upregulated proteins and 17 downregulated proteins. Ten proteins were verified, and Alpha-1-Antitrypsin (a1AT) had a significantly elevated expression in women with AUB associated with the Cu IUD compared with healthy controls (p = 0.026) and a high area under the curve value (0.656), as well as sensitivity (64.9%) and specificity (71.9%). CONCLUSION: This is the first study to explore changes in serum protein and the underlying mechanisms of AUB associated with the Cu IUD via TMT technology. a1AT with biomarker potential was validated. These findings might provide an experimental basis for the early diagnosis or treatment of AUB associated with the Cu IUD.