The innate immune response following multivalent dengue vaccination and implications for protection against dengue challenge

• Text
• PDF

Abstract

Understanding the immune response to dengue virus (DENV) is essential for developing a dengue vaccine that is protective against all four DENV serotypes. We evaluated the immune response post-vaccination (live attenuated tetravalent dengue vaccine TV005 or trivalent admixture) and post-challenge with DEN2Δ30 (Tonga/74) to better understand the importance of homotypic immunity in vaccine protection. Significant increases in IP-10 expression were observed following receipt of either the trivalent or tetravalent vaccine. After challenge, a large increase in IP-10 expression was observed in the placebo (FCH = 4.5) and trivalent admixture groups (FCH = 2.3) but not in the tetravalent vaccine group (FCH = 1.1). MCP-1, IL-1RA, and MIP-1β exhibit a similar pattern as IP-10. These results demonstrate protective effects of trivalent and tetravalent vaccines against DENV, but suggest a better protective effect with the tetravalent vaccine compared to the trivalent admixture. We also explored the post-vaccination and post-challenge immune response differences between black participants and white participants. White participants respond to vaccine differently from black participants, with black participants receiving trivalent and tetravalent vaccines respond strongly and white participants only transiently in trivalent group. In response to challenge, white participants elicit a stronger response than black participants. These results may explain why white participants may have a more vigorous DENV immune response than black participants reported in literature.

Authors

Ruixue Hou, Lewis E. Tomalin, Jessica Pintado Silva, Seunghee Kim-Schulze, Stephen S. Whitehead, Ana Fernandez-Sesma, Anna P. Durbin, Mayte Suárez-Fariñas

Activated CLL cells regulate IL17F producing Th17 cells in miR155 dependent and outcome specific manners

• Text
• PDF

Abstract

Chronic lymphocytic leukemia (CLL) results from expansion of a CD5+ B-cell clone that requires interactions with other cell types, including T cells. Moreover, CLL patients have elevated circulating IL17A+ and IL17F+ CD4+ T cells (Th17s), with higher IL17A+Th17s correlating with better outcomes. We report that CLL Th17s express more miR155, a Th17 differentiation regulator, than control Th17s, despite naïve CD4+ T cell (TN) basal miR155 levels being similar in both. We also found that CLL cells directly regulate miR155 levels in TN, thereby affecting Th17 differentiation by documenting that: co-culturing TN with resting (Brest) or activated (Bact) CLL cells alters the magnitude and direction of T-cell miR155 levels; CLL Bact promote IL17A+ and IL17F+ T cell generation by a miR155-dependent mechanism, confirmed by miR155 inhibition; co-cultures of TN with CLL Bact lead to a linear correlation between the degree and direction of T-cell miR155 expression changes and IL17F production, but not IL17A; Bact-mediated changes in TN miR155 expression correlate with outcome, irrespective of IGHV mutation status, a strong prognostic indicator. Together, the results identify a previously unrecognized CLL Bact-dependent mechanism, upregulation of TN miR155 expression and subsequent enhancement of IL17F+ Th17 generation, that favors better clinical courses.

Authors

Byeongho Jung, Gerardo Ferrer, Pui Yan Chiu, Rukhsana Aslam, Anita Ng, Florencia Palacios, Michael Wysota, Martina Cardillo, Jonathan E. Kolitz, Steven L. Allen, Jacqueline C. Barrientos, Kanti R. Rai, Nicholas Chiorazzi, Barbara Sherry

Biological aging of CNS-resident cells alters the clinical course and immunopathology of autoimmune demyelinating disease

• Text
• PDF

Abstract

Biological aging is the strongest factor associated with the clinical phenotype of multiple sclerosis (MS). Relapsing remitting MS (RRMS) typically presents in the third or fourth decade, while the mean age of presentation of progressive MS (pMS) is 45 years old. Here we show that experimental autoimmune encephalomyelitis (EAE), induced by the adoptive transfer of encephalitogenic CD4+ Th17 cells, is more severe, and less like to remit, in middle-aged compared with young adult mice. Donor T cells and neutrophils are more abundant, while B cells are relatively sparse, in central nervous system (CNS) infiltrates of the older mice. Experiments with reciprocal bone marrow chimeras demonstrate that radio-resistant, non-hematopoietic cells play a dominant role in shaping age-dependent features of the neuroinflammatory response, as well as the clinical course, during EAE. Reminiscent of pMS, EAE in middle-aged adoptive transfer recipients is characterized by widespread microglial activation. Microglia from older mice express a distinctive transcriptomic profile, suggestive of enhanced chemokine synthesis and antigen presentation. Collectively, our findings suggest that drugs that suppress microglial activation, and acquisition or expression of aging-associated properties, may be beneficial in the treatment of progressive forms of inflammatory demyelinating disease.

Authors

Jeffrey R. Atkinson, Andrew D. Jerome, Andrew R. Sas, Ashley Munie, Cankun Wang, Anjun Ma, William D. Arnold, Benjamin M. Segal

Glucose supply and glycolysis inhibition shape the clinical fate of Staphylococcus epidermidis-infected preterm newborns

• Text
• PDF

Abstract

Preterm infants are susceptible to bloodstream infection by coagulase-negative staphylococci (CONS) that can lead to sepsis. High parenteral glucose supplement is commonly used to support their growth and energy expenditure, but may exceed endogenous regulation during infection, causing dysregulated immune response and clinical deterioration. Using a preterm piglet model of neonatal CONS sepsis induced by Staphylococcus epidermidis infection, we demonstrate the delicate interplay between immunity and glucose metabolism to regulate the host infection response. Circulating glucose levels, glycolysis and inflammatory response to infection are closely connected across the states of tolerance, resistance and immunoparalysis. Further, high parenteral glucose provision during infection induces hyperglycemia, elevated glycolysis and inflammation, leading to metabolic acidosis and sepsis, whereas glucose restricted individuals are clinically unaffected with increased gluconeogenesis to maintain moderate hypoglycemia. Finally, standard glucose supply maintaining normoglycemia or pharmacological glycolysis inhibition enhances bacterial clearance and dampens inflammation but fails to prevent sepsis. Our results uncover how blood glucose and glycolysis controls circulating immune responses, in turn determining the clinical fate of CONS infected preterm individuals. This questions the current practice of parenteral glucose supply for preterm infants during infection.

Authors

Tik Muk, Anders Brunse, Nicole L. Henriksen, Karoline Aasmul-Olsen, Duc Ninh Nguyen

Vertical sleeve gastrectomy induces enteroendocrine cell differentiation of intestinal stem cells through bile acid signaling

• Text
• PDF

Abstract

Vertical sleeve gastrectomy (VSG) results in an increase in the number of hormone-secreting enteroendocrine cells (EECs) in the intestinal epithelium, however the mechanism remains unclear. Notably, the beneficial effects of VSG are lost in a mouse model lacking the nuclear bile acid receptor, farnesoid X receptor (FXR). FXR is a nuclear transcription factor that has been shown to regulate intestinal stem cell (ISC) function in cancer models. Therefore, we hypothesized that the VSG-induced increase in EECs is due to changes in intestinal differentiation driven by an increase in bile acid signaling through FXR. To test this, we performed VSG in mice that express eGFP in ISC/progenitor cells and performed RNA-seq on GFP-positive cells sorted from the intestinal epithelia. We also assessed changes in EEC number (marked by GLP-1) in mouse intestinal organoids following treatment with bile acids, an FXR agonist, and a FXR antagonist. RNA-seq of ISCs revealed that bile acids receptors are expressed in ISCs and that VSG explicitly alters expression of several genes that regulate EEC differentiation. Mouse intestinal organoids treated with bile acids and two different FXR agonists increased GLP-1-positive cell numbers, and administration of an FXR antagonist blocked these effects. Taken together, these data indicate that VSG drives ISC fate towards EEC differentiation through bile acid signaling.

Authors

Ki-Suk Kim, Bailey C.E. Peck, Yu-Han Hung, Kieran Koch-Laskowski, Landon Wood, Priya H. Dedhia, Jason R. Spence, Randy J. Seeley, Praveen Sethupathy, Darleen A. Sandoval

CD206⁺ tumor-associated macrophages cross-present tumor antigen and drive anti-tumor immunity

• Text
• PDF

Abstract

In many solid cancers, tumor-associated macrophages (TAM) represent the predominant myeloid cell population. Antigen (Ag) cross-presentation leading to tumor Ag-directed cytotoxic CD8+ T cell responses is crucial for anti-tumor immunity. However, the role of recruited monocyte-derived macrophages, including TAM, as potential cross-presenting cells is not well understood. Here, we show that primary human as well as mouse CD206+ macrophages are effective in functional cross-presentation of soluble self and non-self Ag, including tumor-associated Ag (TAA) as well as viral Ag. To confirm the presence of cross-presenting TAM in vivo, we performed phenotypic and functional analysis of TAM from B16-F10 and CT26 syngeneic tumor models and have identified CD11b+F4/80hiCD206+ TAM to effectively cross-present TAA. We show that CD11b+CD206+ TAM represent the dominant tumor-infiltrating myeloid cell population, expressing a unique cell surface repertoire, promoting Ag cross-presentation and Ag-specific CD8+ T cell activation comparable to cross-presenting CLEC9A+ dendritic cells (cDC1). The presence of cross-presenting CD206+ TAM is associated with reduced tumor burden in mouse syngeneic tumor models and with improved overall survival in cutaneous melanoma patients. Therefore, the demonstration of effective Ag cross-presentation capabilities of CD206+ TAM, including their clinical relevance, expands our understanding of TAM phenotypic diversity and functional versatility.

Authors

Madhura Modak, Ann-Kathrin Mattes, Daniela Reiss, Wioletta Skronska-Wasek, Rebecca Langlois, Nicolas Sabarth, Renate Konopitzky, Fidel Ramírez, Katharina Lehr, Tobias Mayr, David Kind, Coralie Viollet, Lee Kim Swee, Jutta Petschenka, Karim Christian El Kasmi, Elfriede Noessner, Kerstin Kitt, Stefan Pflanz

MTG16 (CBFA2T3) regulates colonic epithelial differentiation, colitis, and tumorigenesis by repressing E protein transcription factors

• Text
• PDF

Abstract

Aberrant epithelial differentiation and regeneration contribute to colon pathologies including inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). MTG16 (CBFA2T3) is a transcriptional corepressor expressed in the colonic epithelium. MTG16 deficiency in mice exacerbates colitis and increases tumor burden in CAC, though the underlying mechanisms remain unclear. Here, we identified MTG16 as a central mediator of epithelial differentiation, promoting goblet and restraining enteroendocrine cell development in homeostasis and enabling regeneration following dextran sulfate sodium (DSS)-induced colitis. Transcriptomic analyses implicated increased E box-binding transcription factor (E protein) activity in MTG16-deficient colon crypts. Using a novel mouse model with a point mutation that attenuates MTG16:E protein interactions (Mtg16P209T), we established that MTG16 exerts control over colonic epithelial differentiation and regeneration by repressing E protein-mediated transcription. Mimicking murine colitis, MTG16 expression was increased in biopsies from patients with active IBD compared to unaffected controls. Finally, uncoupling MTG16:E protein interactions partially phenocopied the enhanced tumorigenicity of Mtg16-/- colon in the azoxymethane(AOM)/DSS-induced model of CAC, indicating that MTG16 protects from tumorigenesis through additional mechanisms. Collectively, our results demonstrate that MTG16, via its repression of E protein targets, is a key regulator of cell fate decisions during colon homeostasis, colitis, and cancer.

Authors

Rachel E. Brown, Justin Jacobse, Shruti A. Anant, Koral M. Blunt, Bob Chen, Paige N. Vega, Chase T. Jones, Jennifer M. Pilat, Frank Revetta, Aidan H. Gorby, Kristy R. Stengel, Yash A. Choksi, Kimmo Palin, M. Blanca Piazuelo, Mary K. Washington, Ken S. Lau, Jeremy A. Goettel, Scott W. Hiebert, Sarah P. Short, Christopher S. Williams

Blimp-1 moulds the epigenetic architecture of IL-21-mediated autoimmune diseases through an autoregulatory circuit

• Text
• PDF

Abstract

PRDM1 encodes B lymphocyte-induced maturation protein 1 (BLIMP1), also known as a master regulator of T-cell homeostasis. We observed a negative relationship between Blimp-1 and IL-21 based on our previous data that Blimp-1 overexpression in T cells suppresses autoimmune diabetes while Blimp-1 deficient T cells contribute to colitis in NOD mice. Reanalysis of published datasets also reveals an inverse correlation between PRDM1 and IL21 in Crohn’s disease. Here, we illustrate that Blimp-1 represses IL-21 by reducing chromatin accessibility and evicting an IL-21 activator c-Maf from the Il21 promoter. Moreover, IL-21-accelerated autoimmune diabetogenesis in small ubiquitin-like modifier-defective c-Maf transgenic mice can be overridden by Blimp-1 overexpression-mediated reduction in permissive chromatin structures at Il21 promoter. An autoregulatory feedback loop to harness IL-21 expression is unveiled by the evidence that addition of IL-21 induces time-dependent Blimp-1 expression and subsequently enriches its binding to the Il21 promoter to suppress IL-21 overproduction. Furthermore, intervention of this feedback loop by IL-21 blockade, IL-21R.Fc administration or IL-21 receptor deletion, attenuates Blimp-1 deficiency-mediated colitis and reinforces the circuit between Blimp-1 and IL-21 in the regulation of autoimmunity. We highlight the translation of Blimp-1-based epigenetic and transcriptomic profiles applicable to a personalized medicine approach in autoimmune diseases.

Authors

Yu-Wen Liu, Shin-Huei Fu, Ming-Wei Chien, Chao-Yuan Hsu, Ming-Hong Lin, Jia-Ling Dong, Rita Jui-Hsien Lu, Yi-Jing Lee, Pao-Yang Chen, Chih-Hung Wang, Huey-Kang Sytwu

EBAG9 controls CD8⁺ T cell memory formation responding to tumor challenge in mice

• Text
• PDF

Abstract

Insight into processes that determine CD8+ T cell memory formation has been obtained from infection models. These models are biased toward an inflammatory milieu and often employ high avidity CD8+ T cells in adoptive transfer procedures. It is unclear whether these conditions mimic the differentiation processes of an endogenous repertoire that proceed upon non-inflammatory conditions prevailing in premalignant tumor lesions. We examined the role of cytolytic capacity on CD8+ T cell fate decisions when primed by tumor cells or by minor histocompatibility antigen-mismatched leukocytes. CD8+ memory commitment was analyzed in Ebag9-deficient mice that exhibit an enhanced tumor cell lysis. This property endowed Ebag9-/- mice with extended control of Tcl-1 oncogene-induced chronic lymphocytic leukemia progression. In Ebag9-/- mice, an expanded memory population was obtained for anti-HY and anti-SV40 T antigen-specific T cells, despite unchanged effector frequencies in the primary response. By comparing the single-cell transcriptomes of CD8+ T cells responding to tumor cell vaccination, we found differential distribution of subpopulations between Ebag9+/+ and Ebag9-/- T cells. In Ebag9-/- cells, these larger clusters contained genes encoding transcription factors regulating memory cell differentiation, along with anti-apoptotic gene functions. Our findings link EBAG9-controlled cytolytic activity and the commitment to the CD8+ memory lineage.

Authors

Armin Rehm, Anthea Wirges, Dana Hoser, Cornelius Fischer, Stefanie Herda, Kerstin Gerlach, Sascha Sauer, Gerald Willimsky, Uta E. Höpken

Lethal synergy between SARS-CoV-2 and Streptococcus pneumoniae in hACE2 mice and protective efficacy of vaccination

• Text
• PDF

Abstract

Secondary infections are frequent complications of viral respiratory infections but the potential consequence of SARS-CoV-2 co-infection with common pulmonary pathogens is poorly understood. We report that co-infection of human ACE2 transgenic mice with sublethal doses of SARS-CoV-2 and Streptococcus pneumoniae results in synergistic lung inflammation and lethality. Mortality was observed regardless of whether SARS-CoV-2 challenge occurred before or after establishment of sublethal pneumococcal infection. Increased bacterial levels following co-infection were associated with alveolar macrophage depletion and treatment with murine GM-CSF reduced lung bacteria numbers and pathology, and partially protected from death. However, therapeutic targeting of interferons, an approach that is effective against influenza co-infections, failed to increase survival. Combined vaccination against both SARS-CoV-2 and pneumococci resulted in 100% protection against subsequent co-infection. The results indicate that when seasonal respiratory infections return to pre-pandemic levels, they could lead to an increased incidence of lethal COVID-19 superinfections, especially among the unvaccinated population.

Authors

Tarani Kanta Barman, Amit K. Singh, Jesse L. Bonin, Tanvir N. Nafiz, Sharon L. Salmon, Dennis W. Metzger