Biology subjects

Perez-Chaparro, P. J.

Publications and source records attributed to Perez-Chaparro, P. J..

3 recordsLinked to original sources

bioRxiv2026

Bone marrow B cell collapse promotes bone metastasis in breast cancer

Metastasis remains the primary cause of cancer-related deaths and is characterized by complex reprogramming of systemic processes. Emerging evidence indicates that extraosseous tumors can rewire bone marrow physiology and disrupt hematopoiesis, thereby compromising effective systemic immune responses. However, how tumor-induced immune alterations in bone marrow contribute to skeletal metastasis remains poorly defined. Here, using immunocompetent mouse models of mammary tumor bone metastasis, we show that mammary cancer cells precondition the bone marrow niche prior to metastatic colonization, driving early remodeling of the microenvironment and depleting bone marrow lymphoid populations. Specifically, cancer cells induce a dramatic B cell reduction, the most abundant lymphoid subset in bone marrow, resulting from dysregulated cell cycle gene expression in pre-B cells, along with impaired B-cell proliferation and differentiation. These findings are further validated in breast cancer bone metastasis patients, who exhibit significant bone marrow B-cell loss alongside disrupted molecular and developmental programs. A causal role for B cells in restraining skeletal metastasis is supported by the finding that experimental B-cell depletion significantly increases both incidence and severity of bone metastasis. Mechanistically, we find that B-cell loss is driven by systemic elevation of G-CSF. Accordingly, pharmacological neutralization of G-CSF significantly reduces both B-cell depletion and bone metastasis susceptibility. Collectively, our data reveal that breast cancer cells can distantly hijack B-cell developmental trajectories, promoting skeletal metastasis. This work identifies B cells and G-CSF as potential therapeutic targets in bone metastasis and highlights the importance of targeting early bone marrow immune dysregulation to prevent or limit skeletal metastasis. HIGHLIGHTSO_LIMammary tumor cells reshape the bone marrow niche inducing B cell loss C_LIO_LIBone marrow B cell development is impaired in mammary tumor metastasis C_LIO_LIExperimental depletion of B cells promotes bone metastasis C_LIO_LIG-CSF mediates B cell loss in mammary tumor metastasis C_LI

cancer biology↗

bioRxiv2026

Ketogenic diet synergistic reprogramming of both host and microbiome promotes tissue regeneration

Nutrition influences host physiological processes, yet how diets reshape host physiology, microbial functions, or host-microbe interactions to promote regeneration remains poorly explored. Here, we show that a ketogenic diet (KD), enriched in fats and low in carbohydrates, reprograms both skin microbial and immune functions to promote tissue repair. KD enhances IL-17A activity in {gamma}{delta} T cells and mucosal-associated invariant T (MAIT) cells, accelerating tissue repair, while KD-induced skin lipidomic alterations enhance both the abundance and metabolic output of Staphylococcus epidermidis. Metatranscriptomic and lipidomic analyses revealed increased riboflavin biosynthesis and sphingomyelinase (Sph)-dependent ceramide production in S. epidermidis under KD conditions. Genetic depletion of microbial ribD, a key enzyme for riboflavin biosynthesis, or of sph compromised the ability of the bacteria to promote tissue repair. Thus, host nutritional status drives tissue regeneration by synergistically rewiring host and microbial functions, providing new insights into how diet can be harnessed to regulate host physiology.

immunology↗

bioRxiv2025

Sulfide is a keystone metabolite for gut homeostasis and immunity

Hydrogen sulfide is a gaseous, reactive molecule specifically enriched in the gastrointestinal tract. Here, we uncover a non-redundant role for sulfide in the control of both microbial and immune homeostasis of the gut. Notably, depletion of sulfide via both pharmaceutical and dietary interventions led to a profound collapse of CD4 T cells in the ileum of the small intestine lamina propria and significant impact on microbial ecology. As a result, mice with reduced sulfide within the gut were deficient in their ability to mount T cell dependent antibody responses to oral vaccine. Mechanistically, our results support the idea that sulfide could act directly on CD4 T cells via enhanced AP-1 activation, leading to heightened proliferation and cytokine production. This study uncovers sulfides as keystone components in gut ecology and provides mechanistic insight between diet, gut sulfide production and mucosal immunity.

immunology↗