Augmented Expansion of Treg Cells From Healthy and Autoimmune Subjects via Adult Progenitor Cell Co-Culture

Growth of human regulatory CD4+ T cells is more tightly controlled than effector T cells due to distinctive molecular programming

Foreign and self-antigens activate CD4+ conventional and regulatory T cells (Tregs) to promote immunity and tolerance, respectively. These cell populations, which depend on interleukin-2 (IL-2), are being expanded and engineered in vitro for adoptive cell therapy (ACT) for cancer and autoimmunity. Here, we investigate the molecular pathways underlying the in vitro expansion of human CD4+ Teff and Tregs to TCR/CD28/IL-2 signaling over 12-days. Temporal integration of differential chromatin accessibility and gene expression revealed similar responses over the first 6 days. After this time, T effector (Teff) cells showed greater expansion that was associated with more robust gene activation and chromatin opening that supported increased activation of mTORC1-dependent signaling and a more energetic phenotype. Thus, Tregs are programmed temporally for more limited expansion in vitro that may benefit ACT for cancer but may be a drawback for autoimmunity. These findings may reflect a mechanism to finely tune Treg numbers to maintain homeostasis in vivo.

Initial or continuous coculture with umbilical cord-derived mesenchymal stromal cells facilitates in vitro expansion of human regulatory T-cell subpopulations

Clinical trials have demonstrated the safety and potential efficacy of ex vivo expanded regulatory T cells (Tregs) for immune-mediated diseases. Nonetheless, achieving consistent and timely Treg yield and purity remains challenging. We aimed to evaluate the potential to enhance culture expansion of primary human total Treg (CD4+/CD25+/CD127lo) and Treg subpopulations through coculture with human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs). In 14- to 21-day anti-CD3/anti-CD28-, interleukin-2-, and rapamycin-containing cultures, fluorescence-activated cell sorting (FACS)-purified total Treg underwent 4-fold greater expansion following hUC-MSC coculture. Potency to suppress T effector cell (Teff) proliferation was equivalent for hUC-MSC-cocultured and control Tregs and correlated with the expression of HLA-DR, CD39, and inducible costimulator (ICOS). The impact of hUC-MSC coculture on ex vivo expansion of 3 FACS-purified Treg subpopulations [CD45RA+ (Subtype I), CD45RA-HLA-DR+ (Subtype II), and CD45RA-HLA-DR- (Subtype III)] was then investigated. Both initial and continuous hUC-MSC coculture yielded significantly higher fold expansion of each Treg subpopulation compared to control. However, the magnitude of enhancement was substantially greater for non-naive (Subtypes II and III) than for naive (Subtype I) Treg. Coculture with hUC-MSC increased HLA-DR expression of all 3 expanded Treg subpopulations while maintaining comparable Teff suppressive potency. For non-naive Treg (Subtypes II and III), both initial and continuous hUC-MSC coculture also increased the final %Foxp3+ and %Helios+. Thus, coculture with clinical-grade hUC-MSC substantially enhances the ex vivo yield, preserves the suppressive potency, and modulates HLA-DR expression of FACS-purified Treg subpopulations with greatest effect on non-naive (CD45RA-) Treg. The findings have potential to facilitate identification, functional characterization, and manufacturing of Treg subpopulations with distinct therapeutic benefits.

Cell therapy with human IL-10-producing ILC2s limits xenogeneic graft-versus-host disease by inhibiting pathogenic T cell responses

Interleukin-10 (IL-10)-producing group 2 innate lymphoid cells (ILC210) regulate inflammatory immune responses, yet their therapeutic potential remains largely unexplored. Here, we demonstrate that cell therapy with human ILC210 inhibits pathogenic T cell responses in humanized mouse models of graft-versus-host disease (GVHD), resulting in reduced GVHD severity and improved overall survival without limiting the graft-versus-leukemia effect. ILC210 conferred superior protection from GVHD than IL-10-/low ILC2s, and blocking IL-10 and IL-4 abrogated ILC210 protective effects, indicating that these cytokines are important for the protective effects of ILC210. Notably, ILC210 provided comparable protection from GVHD to regulatory T cells without impairing T cell engraftment, instead decreasing intestinal T cell infiltration and suppressing CD4+ Th1 and CD8+ Tc1 cells. CITE-seq of expanded ILC2s revealed CD49d and CD86 are markers that allow for enrichment of ILC210 from conventional ILC2s and tracking of ILC210 in patient studies. Altogether, these findings demonstrate the potential of ILC210 in cell therapies for GVHD and other immune-mediated diseases.

Latent human herpesvirus 6 is reactivated in CAR T cells

Cell therapies have yielded durable clinical benefits for patients with cancer, but the risks associated with the development of therapies from manipulated human cells are understudied. For example, we lack a comprehensive understanding of the mechanisms of toxicities observed in patients receiving T cell therapies, including recent reports of encephalitis caused by reactivation of human herpesvirus 6 (HHV-6)1. Here, through petabase-scale viral genomics mining, we examine the landscape of human latent viral reactivation and demonstrate that HHV-6B can become reactivated in cultures of human CD4+ T cells. Using single-cell sequencing, we identify a rare population of HHV-6 'super-expressors' (about 1 in 300-10,000 cells) that possess high viral transcriptional activity, among research-grade allogeneic chimeric antigen receptor (CAR) T cells. By analysing single-cell sequencing data from patients receiving cell therapy products that are approved by the US Food and Drug Administration2 or are in clinical studies3-5, we identify the presence of HHV-6-super-expressor CAR T cells in patients in vivo. Together, the findings of our study demonstrate the utility of comprehensive genomics analyses in implicating cell therapy products as a potential source contributing to the lytic HHV-6 infection that has been reported in clinical trials1,6-8 and may influence the design and production of autologous and allogeneic cell therapies.

Systemic immune profiling of Omicron-infected subjects inoculated with different doses of inactivated virus vaccine

SARS-CoV-2 primary strain-based vaccination exerts a protective effect against Omicron variants-initiated infection, symptom occurrence, and disease severity in a booster-dependent manner. Yet, the underlying mechanisms remain unclear. During the 2022 Omicron outbreak in Shanghai, we enrolled 122 infected adults and 50 uninfected controls who had been unvaccinated or vaccinated with two or three doses of COVID-19 inactive vaccines and performed integrative analysis of 41-plex CyTOF, RNA-seq, and Olink on their peripheral blood samples. The frequencies of HLA-DRhi classical monocytes, non-classical monocytes, and Th1-like Tem tended to increase, whereas the frequency of Treg was reduced by booster vaccine, and they influenced symptom occurrence in a vaccine dose-dependent manner. Intercorrelation and mechanistic analysis suggested that the booster vaccination induced monocytic training, which would prime monocytic activation and maturation rather than differentiating into myeloid-derived suppressive cells upon Omicron infections. Overall, our study provides insights into how booster vaccination elaborates protective immunity across SARS-CoV-2 variants.

Exogenous monocyte myeloid-derived suppressor cells ameliorate immune imbalance, neuroinflammation and cognitive impairment in 5xFAD mice infected with Porphyromonas gingivalis

BACKGROUND

Periodontitis is closely associated with the pathogenesis of Alzheimer's disease (AD). Porphyromonas gingivalis (Pg), the keystone periodontal pathogen, has been reported in our recent study to cause immune-overreaction and induce cognitive impairment. Monocytic myeloid-derived suppressor cells (mMDSCs) possess potent immunosuppressive function. It is unclear whether mMDSCs-mediated immune homeostasis is impaired in AD patients with periodontitis, and whether exogenous mMDSCs could ameliorate immune-overreaction and cognitive impairment induced by Pg.

METHODS

To explore the influence of Pg on cognitive function, neuropathology and immune balance in vivo, 5xFAD mice were treated with live Pg by oral gavage, three times a week for 1 month. The cells of peripheral blood, spleen and bone marrow from 5xFAD mice were treated with Pg to detect the proportional and functional alterations of mMDSCs in vitro. Next, exogenous mMDSCs were sorted from wild-type healthy mice and intravenously injected into 5xFAD mice that were infected with Pg. We used behavioral tests, flow cytometry and immunofluorescent staining to evaluate whether exogenous mMDSCs could ameliorate the cognitive function, immune homeostasis and reduce neuropathology exacerbated by Pg infection.

RESULTS

Pg exacerbated cognitive impairment in 5xFAD mice, with the deposition of amyloid plaque and increased number of microglia in the hippocampus and cortex region. The proportion of mMDSCs decreased in Pg-treated mice. In addition, Pg reduced the proportion and the immunosuppressive function of mMDSCs in vitro. Supplement of exogenous mMDSCs improved the cognitive function, and enhanced the proportions of mMDSCs and IL-10⁺ T cells of 5xFAD mice infected with Pg. At the same time, supplement of exogenous mMDSCs increased the immunosuppressive function of endogenous mMDSCs while decreased the proportions of IL-6⁺ T cells and IFN-γ⁺ CD4⁺ T cells. In addition, the deposition of amyloid plaque decreased while the number of neurons increased in the hippocampus and cortex region after the supplement of exogenous mMDSCs. Furthermore, the number of microglia increased with an increase in the proportion of M2 phenotype.

CONCLUSIONS

Pg can reduce the proportion of mMDSCs, induce immune-overreaction, and exacerbate the neuroinflammation and cognitive impairment in 5xFAD mice. Supplement of exogenous mMDSCs can reduce the neuroinflammation, immune imbalance and cognitive impairment in 5xFAD mice infected with Pg. These findings indicate the mechanism of AD pathogenesis and Pg-mediated promotion of AD, and provide a potential therapeutic strategy for AD patients.

Regulatory T cells as a therapeutic approach for inflammatory bowel disease

Foxp3+ T regulatory (Treg) cells suppress inflammation and are essential for maintaining tissue homeostasis. A growing appreciation of tissue-specific Treg functions has built interest in leveraging the endogenous suppressive mechanisms of these cells into cellular therapeutics in organ-specific diseases. Notably, Treg cells play a critical role in maintaining the intestinal environment. As a barrier site, the gut requires Treg cells to mediate interactions with the microbiota, support barrier integrity, and regulate the immune system. Without fully functional Treg cells, intestinal inflammation and microbial dysbiosis ensue. Thus, there is a particular interest in developing Treg cellular therapies for intestinal inflammatory disease, such as inflammatory bowel disease (IBD). This article reviews some of the critical pathways that are dysregulated in IBD, Treg cell mechanisms of suppression, and the efforts and approaches in the field to develop these cells as a cellular therapy for IBD.

ASPM, CDC20, DLGAP5, BUB1B, CDCA8, and NCAPG May Serve as Diagnostic and Prognostic Biomarkers in Endometrial Carcinoma

Uterine Corpus Endometrial Carcinoma (UCEC), the most common gynecologic malignancy in developed countries, remains to be a major public health problem. Further studies are surely needed to elucidate the tumorigenesis of UCEC. Herein, intersecting 203 differentially expressed genes (DEGs) were identified with the GSE17025, GSE63678, and The Cancer Genome Atlas-UCEC datasets. The Gene Ontology/Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis and protein-protein interaction (PPI) network were performed on those 203 DEGs. Intriguingly, 6 of the top 10 nodes in the PPI network were related to unfavorable prognosis, that is, ASPM, CDC20, DLGAP5, BUB1B, CDCA8, and NCAPG. The mRNA and protein expression levels of the 6 hub genes were elevated in UCEC tissues compared to normal tissues. Higher expression of the 6 hub genes was associated with poor prognostic clinicopathological characteristics. The receiver operating characteristic curve suggested the significant diagnostic ability of the 6 hub genes for UCEC. Then, underlying pathogeneses of UCEC including promoter methylation level, TP53 mutation status, genomic genetic variation, and immune cells infiltration were analyzed. The mRNA expression level of the 6 hub genes was also higher in cervical squamous cell carcinoma and endocervical adenocarcinoma, uterine carcinosarcoma, and ovarian serous cystadenocarcinoma tissues than in corresponding normal tissues. In conclusion, ASPM, CDC20, DLGAP5, BUB1B, CDCA8, and NCAPG may be considered diagnostic and prognostic biomarkers in UCEC.