Schistosomiasis affects over 250 million people, predominantly in Sub-Saharan Africa. In Schistosoma -endemic regions a lack of natural sterilizing immunity means individuals are repeatedly infected, treated and reinfected. Due to difficulties in tracking infection in endemic areas, the kinetics of the host immune response during these reinfections have not been elucidated. Here, we use repeated (3x) controlled human Schistosoma mansoni ( Sm ) infection (repeated CHI) to directly study how antigen-specific T cells develop during reinfection. We compared these responses to natural Sm -infected endemic Ugandan individuals. We report that a mixed Th1/Th2/regulatory CD4 + T cell response develops in repeated CHI, primarily against adult worm antigens. Adult worm-specific responses after repeated CHI were similar to those observed in naturally infected endemic participants. However, endemic participants showed differential responses to antigens from the egg and cercariae life-cycle stages. Repeated CHI (3x) with sequential exposure to Sm cercariae of different sexes (male-female-male) revealed an elevated CD4 + T cell cytokine response to adult worm and egg antigens. Our findings demonstrate that reinfection with single-sex schistosomes elicits adult worm-specific T cell cytokine responses that reflect endemic-natural infection, highlighting the translatability of the CHI model to natural infection in endemic settings. Overall, this study advances our understanding of how schistosome immune responses develop over reinfection cycles in the human host, thereby increasing our understanding of the immunology of natural schistosome (re)infection.

The presence of metastases in mediastinal lymph nodes (LNs) is essential for planning lung cancer treatment and assessing anticancer immune responses. The aim of the study was to assess LNs for the presence of neoplastic cells and evaluate lung cancer-selected antigen expression. LN aspirates were obtained during an EBUS/TBNA procedure. The cells were analyzed using a hematological analyzer and flow cytometry. It was possible to indicate the presence of cells characterized by high fluorescence connected with high metabolic activity using a hematological analyzer and to determine their non-hematopoietic origin using flow cytometry. Using these methods together, we detected very quickly a high proportion of cancer cells in LNs. We noticed that it was possible to determine a high expression of EpCAM, TTF-1, Ki67, cytokeratin, HER, and differences between non-small-cell (NSCLC) and small-cell lung cancer (SCLC) for the antigens MUC-1, CD56, HLA-DR, CD39, CD184, PD-L1, PD-L2 and CTLA-4 on tumor cells. We report, for the first time, that the detection of tumor cells in LNs with the expression of specific antigens is easy to evaluate using a hematological analyzer and flow cytometry in EBUS/TBNA samples. Such precise characteristics of non-hematopoietic cells in LNs may be of great diagnostic importance in the detection of micrometastases.

ABSTRACT Transcriptional control of transgene expression can be linked to dynamic changes in cellular states if this is accompanied by differential expression of transcription factors (TFs). Synthetic promoters (SPs) designed to respond to the desired TFs can provide this regulation with compactness, specificity, and orthogonality. T cells display differentially expressed TFs according to the functional state. In solid tumors, the highly immunosuppressive TME and the chronic exposure to antigens lead to a progression of T cells from a functional to a dysfunctional state known as exhaustion (Tex), in which their power against cancer cells is strongly compromised. Importantly, this transition is accompanied by a marked increase of several TFs, among other factors, that drive targeted genetic programs. Strategies to detect and mitigate Tex are extremely needed. Here, we design SPs that respond to TFs differentially expressed in activated and exhausted T cells to enable new classifiers of the functional/dysfunctional states. We developed a library of over 80 SPs responsive to 7 TFs. The SPs showed broad strength of activation of reporter genes or immunomodulatory molecules in HEK293 and Jurkat T cell lines. Moreover, using a transfer learning strategy we show SPs strength predictability. By combining SPs responding to different TFs, we created Boolean logic gates and implemented a feed-forward design that was previously shown to reduce noise in the OFF-state. Finally, as proof of principle, we demonstrate the dynamic activation of the NR4A2-responsive SP according to the T cell state in primary human CD8+ T cells. Collectively we present a sensing platform that provides a versatile tool to study and monitor the dynamic changes occurring in T cells. In perspective the biosensors coupled to therapeutic genes can be used to reprogram the TME and reinvigorate the T cell anti-tumoral functionality, preventing or reverting the exhausted phenotype. Graphical Abstract Created with BioRender.com .

Dendritic cell (DC) activation and function are underpinned by profound changes in cellular metabolism. Several studies indicate that the ability of DCs to promote tolerance is dependent on catabolic metabolism. Yet the contribution of AMP-activated kinase (AMPK), a central energy sensor promoting catabolism, to DC tolerogenicity remains unknown. Here, we show that AMPK activation renders human monocyte-derived DCs tolerogenic as evidenced by an enhanced ability to drive differentiation of regulatory T cells, a process dependent on increased RALDH activity. This is accompanied by several metabolic changes, including increased breakdown of glycerophospholipids, enhanced mitochondrial fission-dependent fatty acid oxidation, and upregulated glucose catabolism. This metabolic rewiring is functionally important as we found interference with these metabolic processes to reduce to various degrees AMPK-induced RALDH activity as well as the tolerogenic capacity of moDCs. Altogether, our findings reveal a key role for AMPK signaling in shaping DC tolerogenicity and suggest AMPK as a target to direct DC-driven tolerogenic responses in therapeutic settings.
© 2024 Brombacher et al.

The discovery of upstream regulatory genes of a gene of interest still remains challenging. Here we applied a scalable computational method to unbiasedly predict candidate regulatory genes of critical transcription factors by searching the whole genome. We illustrated our approach with a case study on the master regulator FOXP3 of human primary regulatory T cells (Tregs). While target genes of FOXP3 have been identified, its upstream regulatory machinery still remains elusive. Our methodology selected five top-ranked candidates that were tested via proof-of-concept experiments. Following knockdown, three out of five candidates showed significant effects on the mRNA expression of FOXP3 across multiple donors. This provides insights into the regulatory mechanisms modulating FOXP3 transcriptional expression in Tregs. Overall, at the genome level this represents a high level of accuracy in predicting upstream regulatory genes of key genes of interest.
© 2024. The Author(s).