Immune cells for microbiota surveillance

Longitudinal profiling of the microbiome at four body sites reveals core stability and individualized dynamics during health and disease

To understand the dynamic interplay between the human microbiome and host during health and disease, we analyzed the microbial composition, temporal dynamics, and associations with host multi-omics, immune, and clinical markers of microbiomes from four body sites in 86 participants over 6 years. We found that microbiome stability and individuality are body-site specific and heavily influenced by the host. The stool and oral microbiome are more stable than the skin and nasal microbiomes, possibly due to their interaction with the host and environment. We identify individual-specific and commonly shared bacterial taxa, with individualized taxa showing greater stability. Interestingly, microbiome dynamics correlate across body sites, suggesting systemic dynamics influenced by host-microbial-environment interactions. Notably, insulin-resistant individuals show altered microbial stability and associations among microbiome, molecular markers, and clinical features, suggesting their disrupted interaction in metabolic disease. Our study offers comprehensive views of multi-site microbial dynamics and their relationship with host health and disease.

Longitudinal profiling of the microbiome at four body sites reveals core stability and individualized dynamics during health and disease

To understand dynamic interplay between the human microbiome and host during health and disease, we analyzed the microbial composition, temporal dynamics, and associations with host multi-omics, immune and clinical markers of microbiomes from four body sites in 86 participants over six years. We found that microbiome stability and individuality are body-site-specific and heavily influenced by the host. The stool and oral microbiome were more stable than the skin and nasal microbiomes, possibly due to their interaction with the host and environment. Also, we identified individual-specific and commonly shared bacterial taxa, with individualized taxa showing greater stability. Interestingly, microbiome dynamics correlated across body sites, suggesting systemic coordination influenced by host-microbial-environment interactions. Notably, insulin-resistant individuals showed altered microbial stability and associations between microbiome, molecular markers, and clinical features, suggesting their disrupted interaction in metabolic disease. Our study offers comprehensive views of multi-site microbial dynamics and their relationship with host health and disease.

Study Highlights

The stability of the human microbiome varies among individuals and body sites.Highly individualized microbial genera are more stable over time.At each of the four body sites, systematic interactions between the environment, the host and bacteria can be detected.Individuals with insulin resistance have lower microbiome stability, a more diversified skin microbiome, and significantly altered host-microbiome interactions.

Intestinal Microbiota: The Driving Force behind Advances in Cancer Immunotherapy

Simple Summary

Despite the great achievements of cancer immunotherapy in a variety of tumors, tumor heterogeneity and drug resistance still plague patients and clinical researchers. In particular, the occurrence of immune-related adverse events forces patients to discontinue cancer immunotherapy. Therefore, it is urgent to optimize cancer immunotherapy and improve the efficacy of immunotherapy. With the iteration of sequencing technology, the microbiome, as the second set of genomes in the body, has been proven to be involved in immunity and metabolism. More and more studies are gradually shifting the perspective to the intestinal microbiota and cancer immunotherapy. The intestinal microbiota reactivates and modulates immune cells in immunotherapy and is expected to become a biomarker for predicting immune efficacy. Targeting to improve the intestinal microbiota can enhance anti-tumor immunity. This advantage is beneficial to control related adverse symptoms and expand the beneficiary population of cancer immunotherapy. This finding can help clinicians comprehensively evaluate the effect of tumor screening and tumor treatment. Therefore, the innovative combination of gut microbiota and cancer immunotherapy is expected to be an active strategy to enhance individualized immune responses.

Abstract

In recent years, cancer immunotherapy has become a breakthrough method to solve solid tumors. It uses immune checkpoint inhibitors to interfere with tumor immune escape to coordinate anti-tumor therapy. However, immunotherapy has an individualized response rate. Moreover, immune-related adverse events and drug resistance are still urgent issues that need to be resolved, which may be attributed to the immune imbalance caused by immune checkpoint inhibitors. Microbiome research has fully revealed the metabolic-immune interaction relationship between the microbiome and the host. Surprisingly, sequencing technology further proved that intestinal microbiota could effectively intervene in tumor immunotherapy and reduce the incidence of adverse events. Therefore, cancer immunotherapy under the intervention of intestinal microbiota has innovatively broadened the anti-tumor landscape and is expected to become an active strategy to enhance individualized responses.

Regulation and Functions of Protumoral Unconventional T Cells in Solid Tumors

The vast majority of studies on T cell biology in tumor immunity have focused on peptide-reactive conventional T cells that are restricted to polymorphic major histocompatibility complex molecules. However, emerging evidence indicated that unconventional T cells, including γδ T cells, natural killer T (NKT) cells and mucosal-associated invariant T (MAIT) cells are also involved in tumor immunity. Unconventional T cells span the innate-adaptive continuum and possess the unique ability to rapidly react to nonpeptide antigens via their conserved T cell receptors (TCRs) and/or to activating cytokines to orchestrate many aspects of the immune response. Since unconventional T cell lineages comprise discrete functional subsets, they can mediate both anti- and protumoral activities. Here, we review the current understanding of the functions and regulatory mechanisms of protumoral unconventional T cell subsets in the tumor environment. We also discuss the therapeutic potential of these deleterious subsets in solid cancers and why further feasibility studies are warranted.

Barrier lymphocytes in spondyloarthritis

PURPOSE OF REVIEW

The clinical overlap between spondyloarthritis (SpA) and inflammation of barrier tissues such as the intestine and skin indicates a role of barrier tissue immunity in the development of SpA. Herein, we review the recent advances in understanding lymphocyte populations and functions within the intestine and skin implicated in the pathophysiology of SpA.

RECENT FINDINGS

A number of unique lymphocyte populations have been identified to be expanded within the gut and skin of patients with SpA, including γδ T cells, mucosa-associated invariant T (MAIT) cells, innate lymphoid cells (ILCs) and T resident memory (TRM) cells. These cells respond to microbial cues at their barrier surface causing cellular activation and generation of interleukin (IL)-17, which is hypothesized to be the mechanism by which they contribute to SpA pathogenesis.

SUMMARY

Understanding how unique lymphocyte populations expand and produce IL-17 in the development of SpA provides insights into the pathophysiology of this disease as well as potential future therapeutic avenues.

Functional inactivation of pulmonary MAIT cells following 5-OP-RU treatment of non-human primates

Targeting MAIT cells holds promise for the treatment of different diseases and infections. We previously showed that treatment of Mycobacterium tuberculosis infected mice with 5-OP-RU, a major antigen for MAIT cells, expands MAIT cells and enhances bacterial control. Here we treated M. tuberculosis infected rhesus macaques with 5-OP-RU intratracheally but found no clinical or microbiological benefit. In fact, after 5-OP-RU treatment MAIT cells did not expand, but rather upregulated PD-1 and lost the ability to produce multiple cytokines, a phenotype resembling T cell exhaustion. Furthermore, we show that vaccination of uninfected macaques with 5-OP-RU+CpG instillation into the lungs also drives MAIT cell dysfunction, and PD-1 blockade during vaccination partly prevents the loss of MAIT cell function without facilitating their expansion. Thus, in rhesus macaques MAIT cells are prone to the loss of effector functions rather than expansion after TCR stimulation in vivo, representing a significant barrier to therapeutically targeting these cells.

Interactions between Gut Microbiota and Immunomodulatory Cells in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases caused by abnormal immune activation and immune tolerance. Immunomodulatory cells (ICs) play a critical role in the maintenance and homeostasis of normal immune function and in the pathogenesis of RA. The human gastrointestinal tract is inhabited by trillions of commensal microbiota on the mucosal surface that play a fundamental role in the induction, maintenance, and function of the host immune system. Gut microbiota dysbiosis can impact both the local and systemic immune systems and further contribute to various diseases, such as RA. The neighbouring intestinal ICs located in distinct intestinal mucosa may be the most likely intermediary by which the gut microbiota can affect the occurrence and development of RA. However, the reciprocal interaction between the components of the gut microbiota and their microbial metabolites with distinct ICs and how this interaction may impact the development of RA are not well studied. Therefore, a better understanding of the gut microbiota, ICs, and their interactions might improve our knowledge of the mechanisms by which the gut microbiota contribute to RA and facilitate the further development of novel therapeutic approaches. In this review, we have summarized the roles of the gut microbiota in the immunopathogenesis of RA, especially the interactions between the gut microbiota and ICs, and further discussed the strategies for treating RA by targeting/regulating the gut microbiota.