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Mudianto, T.

Publications and source records attributed to Mudianto, T..

4 recordsLinked to original sources

Lymphatic constraint of germinal centers optimizes protective antibody responses

Immunization strategies are central to pathogen control, where efficacy relies on antigen uptake, distribution, persistence, and inflammatory context. We recently demonstrated that dermal lymphatic capillaries regulate antigen presentation in lymph nodes (LN) by restraining fluid and virion transport following vaccinia virus (VACV) infection by skin scarification. Concurrently, a perifollicular, LN lymphangiogenic response encapsulates expanding B cell follicles. Given the important role of antigen transport and uptake on humoral immunity, we tested the hypothesis that lymphatic remodeling in the skin and LNs regulates germinal center (GC)-dependent antibody responses during infection. Using a model of lymphatic-specific VEGFR2 inhibition, we found that inhibiting viral-induced lymphatic remodeling in skin and LNs prompted significant GC expansion but paradoxically decreases protective VACV-specific class-switched antibodies. While the larger GC responses appeared structurally normal, they failed to support a proliferative burst consistent with clonal selection. Mathematical modeling revealed that this disconnect between GC size and function arises from impaired productive T follicular cell interactions in larger GC volumes and consistent with this finding, the optimal GC size was evolutionarily conserved across diverse mammals. Finally, we found that the presence of virus in the LN initiates these changes in GC function, inhibits LN lymphangiogenesis, increases B cell follicle size, and reduces selection efficiency. Therefore, protecting LN lymphatic vessels from virus-induced interferons rescues perifollicular lymphatic growth and follicle size, indicating that LN lymphangiogenesis directly constrains the follicular response. In summary, this study underscores the central role of lymphatic remodeling in compartmentalizing antigen and inflammatory signals to optimize GC fitness and protective antibody responses.

immunology↗

CXCR6 promotes dermal CD8+ T cell survival and transition to long-term tissue residence

Tissue resident memory T cells (TRM) provide protection against local re-infection, and yet the interstitial signals necessary for their formation and persistence remain incompletely understood. Here we show that antigen-dependent induction of the chemokine receptor, CXCR6, is a conserved adaptation to peripheral tissue infiltration that promotes TRM formation after viral infection. Deficient TRM formation in the absence of CXCR6 was not explained by canonical trafficking as CXCR6 was not required for tissue entry, was dispensable for the early accumulation of antigen-specific CD8+ T cells in skin, and did not restrain their exit. Further, single cell sequencing indicated that Cxcr6-/- CD8+ T cells were competent to acquire a transcriptional program of residence and TRM that formed were equally functional compared to their WT counterparts when reactivated greater than 100 days post primary infection. The reduced numbers observed at memory time points, where instead found to associate with impaired redox homeostasis and antioxidant capacity during the transition from effector to memory states. As such, Cxcr6-/- CD8+ T cells exhibited increased rates of apoptosis in the dermis relative to controls, which led to reduced numbers of TRM in the epidermis at memory. CXCR6 therefore promotes the metabolic adaptation of T cells as they engage antigen in tissue to increase the probability of memory differentiation and long-term residence. One Sentence SummaryCXCR6 promotes mechanisms of cellular adaptation to tissue that support local survival and the transition to tissue residence.

immunology↗

Infection-induced dermal lymphatic zippering restricts viral dissemination from skin and promotes anti-viral CD8+ T cell expansion.

Lymphatic vessels are often considered passive conduits that rapidly flush antigenic material, pathogens, and cells to draining lymph nodes. Recent evidence, however, suggests that lymphatic vessels actively regulate diverse processes from antigen transport to leukocyte trafficking and dietary lipid absorption. Here we tested the hypothesis that dermal lymphatic transport is dynamic and contributes to innate host defense during viral infection. We demonstrate that cutaneous vaccinia virus infection activates the tightening of lymphatic interendothelial junctions, termed zippering, in a VEGFA/VEGFR2-dependent manner. Both antibody-mediated blockade of VEGFA/VEGFR2 and lymphatic-specific deletion of Vegfr2 impaired lymphatic capillary zippering and increased fluid flux out of tissue. Strikingly, inhibition of lymphatic zippering allows viral dissemination to draining lymph nodes independent of dendritic cell migration and impairs CD8+ T cell priming. These data indicate that infection-induced dermal lymphatic capillary zippering is a context-dependent, active mechanism of innate host defense that limits interstitial fluid and virion flux and promotes protective, anti-viral CD8+ T cell responses. SummaryCutaneous infection with vaccinia virus induces VEGFR2-dependent dermal lymphatic capillary zippering. This tightening of lymphatic junctions exacerbates tissue edema, sequesters virus, and promotes anti-viral CD8+ T cell responses. Dermal lymphatic capillaries are therefore an active component of innate host defense.

immunology↗

Identification of STK25 as a direct activator of LATS signaling

The Hippo pathway maintains tissue homeostasis by negatively regulating the oncogenic transcriptional co-activators YAP and TAZ. Though functional inactivation of the Hippo pathway is common in tumors, mutations in core pathway components are rare. Thus, understanding how tumor cells inactivate Hippo signaling remains a key unresolved question. Here, we identify the kinase STK25 as a novel activator of Hippo signaling. We demonstrate that loss of STK25 promotes YAP/TAZ activation and enhanced cellular proliferation, even under normally growth-suppressive conditions. We reveal that STK25 activates LATS via a previously unobserved mechanism, in which STK25 directly phosphorylates the LATS activation loop. This represents a new paradigm in Hippo activation and distinguishes STK25 from all other identified kinase activators of LATS. STK25 is significantly focally deleted across a wide spectrum of human cancers, suggesting STK25 loss may represent a common mechanism by which tumor cells functionally impair the Hippo tumor suppressor pathway.

cell biology↗