Pathogen-associated T follicular helper cell plasticity is critical in anti-viral immunity

Ononin inhibits triple-negative breast cancer lung metastasis by targeting the EGFR-mediated PI3K/Akt/mTOR pathway

The spreading of cancer cells from the primary tumor site to other parts of the body, known as metastasis, is the leading cause of cancer recurrence and mortality in patients with triple-negative breast cancer (TNBC). Overexpression of epidermal growth factor receptor (EGFR) is observed in approximately 70% of TNBC patients. EGFR is crucial for promoting tumor metastasis and associated with poor prognosis. Therefore, it is vital to identify effective therapeutic strategies targeting EGFR inhibition. Ononin, an isoflavonoid found in various plants, such as clover and soybeans, has been shown to have anticancer properties in several cancers. In the present study, we aimed to investigate the effects of ononin on TNBC lung metastasis and the associated molecular pathways. We used various assays, including cell viability, colony formation, Transwell, wound healing, ELISA, Western blotting, and staining techniques, to achieve this objective. The results demonstrated that ononin effectively suppressed cellular proliferation and induced apoptosis, as evidenced by the cell viability assay, colony formation assay, and expression of apoptosis markers, and reduced the metastatic capabilities of TNBC cells. These effects were achieved through the direct suppression of cell adhesion, invasiveness and motility. Furthermore, in TNBC xenograft lung metastatic models, ononin treatment significantly reduced tumor growth and lung metastasis. Additionally, ononin reversed the epithelial-mesenchymal transition (EMT) by downregulating the expression of EMT markers and matrix metalloproteinases, as confirmed by Western blot analysis. Furthermore, ononin treatment reduced EGFR phosphorylation and suppressed the PI3K, Akt, and mTOR signaling pathways, which was further confirmed using EGFR agonists or inhibitors. Importantly, ononin treatment did not exert any toxic effects on liver or kidney function. In conclusion, our findings suggest that ononin is a safe and potentially therapeutic treatment for TNBC metastasis that targets the EGFR-mediated PI3K/Akt/mTOR pathway. Further studies are warranted to validate its efficacy and explore its potential clinical applications.

A novel memory-like Tfh cell subset is precursor to effector Tfh cells in recall immune responses

T follicular helper (Tfh) cells, essential for germinal center reactions, are not identical, with different phenotypes reported. Whether, when, and how they generate memory cells is still poorly understood. Here, through single-cell RNA-sequencing analysis of CXCR5+Bcl6+ Tfh cells generated under different conditions, we discovered, in addition to PD-1hi effector Tfh cells, a CD62L+PD1low subpopulation. CD62L-expressing Tfh cells developed independently from PD-1+ cells and not in direct contact with B cells. More importantly, CD62L+ Tfh cells expressed memory- and stemness-associated genes, and with better superior long-term survival, they readily generated PD-1hi cells in the recall response. Finally, KLF2 and IL7R, also highly expressed by CD62L+ Tfh cells, were required to regulate their development. Our work thus demonstrates a novel Tfh memory-like cell subpopulation, which may benefit our understanding of immune responses and diseases.

Innate and adaptive immune abnormalities underlying autoimmune diseases: the genetic connections

With the exception of an extremely small number of cases caused by single gene mutations, most autoimmune diseases result from the complex interplay between environmental and genetic factors. In a nutshell, etiology of the common autoimmune disorders is unknown in spite of progress elucidating certain effector cells and molecules responsible for pathologies associated with inflammatory and tissue damage. In recent years, population genetics approaches have greatly enriched our knowledge regarding genetic susceptibility of autoimmunity, providing us with a window of opportunities to comprehensively re-examine autoimmunity-associated genes and possible pathways. In this review, we aim to discuss etiology and pathogenesis of common autoimmune disorders from the perspective of human genetics. An overview of the genetic basis of autoimmunity is followed by 3 chapters detailing susceptibility genes involved in innate immunity, adaptive immunity and inflammatory cell death processes respectively. With such attempts, we hope to expand the scope of thinking and bring attention to lesser appreciated molecules and pathways as important contributors of autoimmunity beyond the 'usual suspects' of a limited subset of validated therapeutic targets.

Phenotypes of peripheral CD4+ T helper cell subsets in pregnant women with HBeAg-negative chronic asymptomatic HBV carriers

Background

Chronic hepatitis B virus (HBV) infection is a major public health problem worldwide, and mother-to-child transmission is the key mode of HBV infection. CD4⁺ T helper (Th) cells play a critical role in the immune microenvironment of specific maternal tolerance to the foetus during pregnancy. However, the roles of Th cell subsets in pregnant women (PW) with chronic asymptomatic HBV carriers (ASCs) remain completely unclear. Here, we aimed to characterize CD4⁺ T-cell immunity in PW with hepatitis Be antigen (HBeAg)-negative chronic ASCs.

Methods

Human peripheral blood mononuclear cells (PBMCs) from PW without HBV infection or with chronic ASCs and healthy controls (HC) were isolated, and CD4⁺ Th cell subsets were detected by flow cytometry in addition to serum cytokines. Serological HBV markers, liver function and hormone levels of these individuals were also tested.

Results

The frequencies of circulating T follicular helper (Tfh) type 2 (Tfh2) cells were significantly evaluated, but Tfh1 cell frequencies were notably decreased in PW compared to HC. Moreover, the frequencies of Th22 cells were only notably increased in PW with chronic ASCs in comparison with PW. Additionally, increased levels of serum IL-4 were positively correlated with Tfh2 cell frequencies in healthy PW. Interestingly, serum P4 levels were positively associated with the frequencies of circulating Tfh2 or Th2 cells but were negatively related to the frequencies of circulating Tfh17 or Th17 cells in healthy PW. Although there were some changes in the other CD4⁺ Th cell frequencies and cytokine levels or other references, significant differences were not found among HC, healthy PW, PW with HBeAg-negative chronic ASCs.

Conclusion

CD4⁺ Th cell subsets played a critical role in the immune microenvironment of PW, and these findings provided potential evidence for why PW with chronic ASCs did not receive antenatal antiviral prophylaxis.

Heterogeneity, subsets, and plasticity of T follicular helper cells in allergy

Antibody responses are critical for protection against pathogens. However, diseases such as allergic rhinitis or food allergy result from aberrant production of IgE antibodies against otherwise innocuous environmental antigens. The production of allergen-specific IgE requires interaction between B cells and CD4⁺ T cells, and a granular understanding of these interactions is required to develop novel therapies for allergic disease. CD4⁺ T cells are exceptionally heterogeneous in their transcriptional, epigenetic, and proteomic profiles, which poses significant challenges when attempting to define subsets relevant to the study of allergy among a continuum of cells. Defining subsets such as the T follicular helper (T_FH) cell cluster provides a shorthand to understand the functions of CD4⁺ T cells in antibody production and supports mechanistic experimentation for hypothesis-driven discovery. With a focus on allergic disease, this Rostrum article broadly discusses heterogeneity among CD4⁺ T cells and provides a rationale for subdividing T_FH cells into both functional and cytokine-skewed subsets. Further, it highlights the plasticity demonstrated by T_FH cells during the primary response and after recall, and it explores the possibility of harnessing this plasticity to reprogram immunity for therapeutic benefit in allergic disease.