Novel mRNA adjuvant ImmunER enhances prostate cancer tumor-associated antigen mRNA therapy via augmenting T cell activity.

Prostate cancer (PCa) is characterized as a "cold tumor" with limited immune responses, rendering the tumor resistant to immune checkpoint inhibitors (ICI). Therapeutic messenger RNA (mRNA) vaccines have emerged as a promising strategy to overcome this challenge by enhancing immune reactivity and significantly boosting anti-tumor efficacy. In our study, we synthesized Tetra, an mRNA vaccine mixed with multiple tumor-associated antigens, and ImmunER, an immune-enhancing adjuvant, aiming to induce potent anti-tumor immunity. ImmunER exhibited the capacity to promote dendritic cells (DCs) maturation, enhance DCs migration, and improve antigen presentation at both cellular and animal levels. Moreover, Tetra, in combination with ImmunER, induced a transformation of bone marrow-derived dendritic cells (BMDCs) to cDC1-CCL22 and up-regulated the JAK-STAT1 pathway, promoting the release of IL-12, TNF-α, and other cytokines. This cascade led to enhanced proliferation and activation of T cells, resulting in effective killing of tumor cells. In vivo experiments further revealed that Tetra + ImmunER increased CD8+T cell infiltration and activation in RM-1-PSMA tumor tissues. In summary, our findings underscore the promising potential of the integrated Tetra and ImmunER mRNA-LNP therapy for robust anti-tumor immunity in PCa.

[Research advances in the development and function of macrophages and classical dendritic cells during resting and infection].

Macrophages (MACs) and classical dendritic cells (cDCs) represent the front line of immune defense, playing crucial roles in both innate and adaptive immunity due to their remarkable tissue specificity and precise adaptation to environmental cues. MACs contribute to maintaining tissue homeostasis and immune surveillance, while cDCs function as the most efficient antigen-presenting cells, playing a critical role in immune responses. These two cell types share similarities and interconnections. Both MACs and cDCs are capable of recognizing pathogens and tissue damage, secreting cytokines to activate other innate immune cells, and initiating or modulating adaptive immunity through interactions with T cells. In this review, we provide a comprehensive analysis of the research advances in the development and functions of MACs and cDCs during resting and infection processes, elucidate their interrelationships and interactions within the immune system, and offer a theoretical basis for in-depth studies of diseases.

Overview of histiocytic and dendritic disorders by the 5th version of WHO Classifi cation of Hematolymphoid Tumours from 2022.

BACKGROUND: Histiocytoses are rare disorders characterized by the accumulation of macrophages, dendritic cells, or monocyte-derived cells in various tissues and organs of children and adults, with a wide range of clinical manifestations, presentations, and histology. The histiocytoses are classified according to the WHO Classification, the last version of which was published in 2022, or according to the Histiocyte Society Classification, with the last version published in 2016. PURPOSE: This text provides an overview of histiocytoses as described in the WHO Classification 2022.

Effects of Injectable Solutions on the Quality of Monocyte-Derived Dendritic Cells for Immunotherapy.

Therapeutic vaccines based on monocyte-derived dendritic cells have been shown to be promising strategies and may act as complementary treatments for viral infections, cancers, and, more recently, autoimmune diseases. Alpha-type-1-polarized dendritic cells (aDC1s) have been shown to induce type-1 immunity with a high capacity to produce interleukin-12p70 (IL-12p70). In the clinical use of cell-based therapeutics, injectable solutions can affect the morphology, immunophenotypic profile, and viability of cells before delivery and their survival after injection. In this sense, preparing a cell suspension that maintains the quality of aDC1s is essential to ensure effective immunotherapy. In the present study, monocytes were differentiated into aDC1s in the presence of IL-4 and GM-CSF. On day 5, the cells were matured by the addition of a cytokine cocktail consisting of IFN-α, IFN-γ, IL-1ß, TNF-α, and Poly I:C. After 48 hr, mature aDC1s were harvested and suspended in two different solutions: normal saline and Ringer's lactate. The maintenance of cells in suspension was evaluated after 4, 6, and 8 hr of storage. Cell viability, immunophenotyping, and apoptosis analyses were performed by flow cytometry. Cellular morphology was observed by electron microscopy, and the production of IL-12p70 by aDC1s was evaluated by ELISA. Compared with normal saline, Ringer's lactate solution was more effective at maintaining DC viability for up to 8 hr of incubation at 4 or 22°C.

Embryo Quality Conditions the Secretory Profile of Tolerogenic Dendritic Cell DC-10 During the Peri-Implantation Period.

PROBLEM: The decidualization process conditions monocytes to the immunosuppressive and tolerogenic dendritic cell (DC)-10 profile, a DC subset with high IL-10 production. Since the implantation process implies an embryo-endometrium-immune crosstalk, here we focused on the ability of embryonic soluble factors to modify decidual DC conditioning accordingly with its quality. METHOD OF STUDY: Human endometrial stromal cell line (HESC) decidualized with medroxyprogesterone and dibutyryl-cAMP (Dec) was stimulated with human embryo-conditioned media (ECM), classified as normal (ND) or impaired developed (ID) for 48 h (n = 18/group). Monocytes isolated from six healthy women were differentiated to DCs with rhGM-CSF+rhIL-4 in the presence/absence of conditioned media (CM) from decidualized cells stimulated with ECM or nontreated. RESULTS: We found that decidualized cells stimulated with ECM sustain a myeloid regulatory cell profile on monocyte-derived culture with increased frequency of CD1a-CD14+ and CD83+CD86low cells. ND-Dec sustained the higher expression of the DC-10 markers, HLA-G and IL-10 whereas ID-Dec diminished IL-10 production (ID-Dec: 135 ± 37.4 vs. Dec: 223.3 ± 49.9 pg/mL, p < 0.05). The treatment with ECM-Dec sustained a higher IL-10 production and prevented the increase of CD83/CD86 after LPS challenge regardless of embryo quality. Notably, TNF-α production increased in ID-Dec cultures (ID-Dec: 475.1 ± 134.7 vs. Dec: 347.5 ± 98 pg/mL, p < 0.05). CONCLUSIONS: Although remaining in a tolerogenic profile compatible with DC-10, DCs can differentially respond to decidual secreted factors based on embryo quality, changing their secretome. These results suggest that in the presence of arrested embryo, DCs could differentially shape the immunological microenvironment, contributing to arrested embryo clearance during the menstrual phase.

Repression of SMAD3 by STAT3 and c-Ski induces conventional dendritic cell differentiation.

A pleiotropic immunoregulatory cytokine, TGF-ß, signals via the receptor-regulated SMADs: SMAD2 and SMAD3, which are constitutively expressed in normal cells. Here, we show that selective repression of SMAD3 induces cDC differentiation from the CD115+ common DC progenitor (CDP). SMAD3 was expressed in haematopoietic cells including the macrophage DC progenitor. However, SMAD3 was specifically down-regulated in CD115+ CDPs, SiglecH- pre-DCs, and cDCs, whereas SMAD2 remained constitutive. SMAD3-deficient mice showed a significant increase in cDCs, SiglecH- pre-DCs, and CD115+ CDPs compared with the littermate control. SMAD3 repressed the mRNA expression of FLT3 and the cDC-related genes: IRF4 and ID2. We found that one of the SMAD transcriptional corepressors, c-SKI, cooperated with phosphorylated STAT3 at Y705 and S727 to repress the transcription of SMAD3 to induce cDC differentiation. These data indicate that STAT3 and c-Ski induce cDC differentiation by repressing SMAD3: the repressor of the cDC-related genes during the developmental stage between the macrophage DC progenitor and CD115+ CDP.

The role of CD83 in the pathogenesis of immune thrombocytopenia.

BACKGROUND: CD83 are closely related to the pathogenesis of immune thrombocytopenia (ITP), but the exact mechanism remains unclear. AIM: To explore the relationship between CD83 and CD4+ T cell subsets and clarify the role of CD83 in the pathogenesis of ITP. METHODS: RT-qPCR and Flow cytometry were used to illustrate CD83 expression. The downregulation and overexpression of DC-CD83 were co-cultured with CD4+ T cells to detect cell proliferation, co-cultured supernatant cytokines and Tregs expression. RESULTS: The results indicate that the ITP patients showed higher expression of CD83 than the healthy controls. The proliferation of CD4+ T cells was inhibited by downregulation of DCs-CD83 but promoted by overexpression of DCs-CD83. siRNA-CD83 inhibited proinflammatory IFN-γ and IL-17 secretion while raising TGF-ß, IL-10 concentrations. Overexpression of DCs-CD83 promoted Tregs expression. CONCLUSION: The Th1/Th2 and Th17/Tregs polarization were reversed via interfering DCs with siRNA-CD83. CD83 plays an important role in ITP pathogenesis, suggesting novel treatment for ITP patients.

TCF1-positive and TCF1-negative TRM CD8 T cell subsets and cDC1s orchestrate melanoma protection and immunotherapy response.

BACKGROUND: Melanoma, the most lethal form of skin cancer, has undergone a transformative treatment shift with the advent of checkpoint blockade immunotherapy (CBI). Understanding the intricate network of immune cells infiltrating the tumor and orchestrating the control of melanoma cells and the response to CBI is currently of utmost importance. There is evidence underscoring the significance of tissue-resident memory (TRM) CD8 T cells and classic dendritic cell type 1 (cDC1) in cancer protection. Transcriptomic studies also support the existence of a TCF7+ (encoding TCF1) T cell as the most important for immunotherapy response, although uncertainty exists about whether there is a TCF1+TRM T cell due to evidence indicating TCF1 downregulation for tissue residency activation. METHODS: We used multiplexed immunofluorescence and spectral flow cytometry to evaluate TRM CD8 T cells and cDC1 in two melanoma patient cohorts: one immunotherapy-naive and the other receiving immunotherapy. The first cohort was divided between patients free of disease or with metastasis 2 years postdiagnosis while the second between CBI responders and non-responders. RESULTS: Our study identifies two CD8+TRM subsets, TCF1+ and TCF1-, correlating with melanoma protection. TCF1+TRM cells show heightened expression of IFN-γ and Ki67 while TCF1- TRM cells exhibit increased expression of cytotoxic molecules. In metastatic patients, TRM subsets undergo a shift in marker expression, with the TCF1- subset displaying increased expression of exhaustion markers. We observed a close spatial correlation between cDC1s and TRMs, with TCF1+TRM/cDC1 pairs enriched in the stroma and TCF1- TRM/cDC1 pairs in tumor areas. Notably, these TCF1- TRMs express cytotoxic molecules and are associated with apoptotic melanoma cells. Both TCF1+ and TCF1- TRM subsets, alongside cDC1, prove relevant to CBI response. CONCLUSIONS: Our study supports the importance of TRM CD8 T cells and cDC1 in melanoma protection while also highlighting the existence of functionally distinctive TCF1+ and TCF1- TRM subsets, both crucial for melanoma control and CBI response.

Environment-responsive dendrobium polysaccharide hydrogel embedding manganese microsphere as a post-operative adjuvant to boost cascaded immune cycle against melanoma.

Rationale: Surgical resection is a primary treatment for solid tumors, but high rates of tumor recurrence and metastasis post-surgery present significant challenges. Manganese (Mn2+), known to enhance dendritic cell-mediated cancer immunotherapy by activating the cGAS-STING pathway, has potential in post-operative cancer management. However, achieving prolonged and localized delivery of Mn2+ to stimulate immune responses without systemic toxicity remains a challenge. Methods: We developed a post-operative microenvironment-responsive dendrobium polysaccharide hydrogel embedded with Mn2+-pectin microspheres (MnP@DOP-Gel). This hydrogel system releases Mn2+-pectin microspheres (MnP) in response to ROS, and MnP shows a dual effect in vitro: promoting immunogenic cell death and activating immune cells (dendritic cells and macrophages). The efficacy of MnP@DOP-Gel as a post-surgical treatment and its potential for immune activation were assessed in both subcutaneous and metastatic melanoma models in mice, exploring its synergistic effect with anti-PD1 antibody. Result: MnP@DOP-Gel exhibited ROS-responsive release of MnP, which could exert dual effects by inducing immunogenic cell death of tumor cells and activating dendritic cells and macrophages to initiate a cascade of anti-tumor immune responses. In vivo experiments showed that the implanted MnP@DOP-Gel significantly inhibited residual tumor growth and metastasis. Moreover, the combination of MnP@DOP-Gel and anti-PD1 antibody displayed superior therapeutic potency in preventing either metastasis or abscopal brain tumor growth. Conclusions: MnP@DOP-Gel represents a promising drug-free strategy for cancer post-operative management. Utilizing this Mn2+-embedding and ROS-responsive delivery system, it regulates surgery-induced immune responses and promotes sustained anti-tumor responses, potentially increasing the effectiveness of surgical cancer treatments.

Sensing of an HIV-1-Derived Single-Stranded RNA-Oligonucleotide Induces Arginase 1-Mediated Tolerance.

Small synthetic oligodeoxynucleotides (ODNs) can mimic microbial nucleic acids by interacting with receptor systems and promoting immunostimulatory activities. Nevertheless, some ODNs can act differently on the plasmacytoid dendritic cell (pDC) subset, shaping their immunoregulatory properties and rendering them suitable immunotherapeutic tools in several clinical settings for treating overwhelming immune responses. We designed HIV-1-derived, DNA- and RNA-based oligonucleotides (gag, pol, and U5 regions) and assessed their activity in conferring a tolerogenic phenotype to pDCs in skin test experiments. RNA-but not DNA-oligonucleotides are capable of inducing tolerogenic features in pDCs. Interestingly, sensing the HIV-1-derived single-stranded RNA-gag oligonucleotide (RNA-gag) requires both TLR3 and TLR7 and the engagement of the TRIF adaptor molecule. Moreover, the induction of a suppressive phenotype in pDCs by RNA-gag is contingent upon the induction and activation of the immunosuppressive enzyme Arginase 1. Thus, our data suggest that sensing of the synthetic RNA-gag oligonucleotide in pDCs can induce a suppressive phenotype in pDCs, a property rendering RNA-gag a potential tool for therapeutic strategies in allergies and autoimmune diseases.

Interleukin-10 as a marker for response to dendritic cells-dribbles immunotherapy in hepatocellular carcinoma, a mice model.

Cancer immunotherapy is a promising strategy in cancer management, including hepatocellular carcinoma (HCC). This experimental study aimed to evaluate interleukin-10 (IL-10) as a biomarker for monitoring the response of tumor-derived autophagosomes vaccine in inducing antitumor immunity in HCC induced mice. It was conducted on 56 BALB/c mice; divided into 20 normal and 36, cancer induced with human liver cancer cell line (HepG2) cells. The latter group was subdivided into a positive control group (n=6) and a treated group (n=30), that was subdivided into 3 subgroups: (A) treated with dendritic cells (DC) vaccine only, (B) treated with vaccine named Dribbles only, and (C) treated with DC plus Dribbles. Serum IL-10 was assessed after immunotherapy. The mean percentage of tumor volume reduction in mice vaccinated by DC plus Dribbles was significantly superior to DC and Dribbles groups (p= 0.013, and p= 0.043, respectively). There was a statistically significant difference in IL-10 levels between different immunotherapy groups (p= 0.0003). As the mean IL-10 level was 19.50 pg/ml for the positive control group, 13 pg/ml for Dribbles group, 10 pg/ml for DCs group and 3.50 pg/ml for DCs plus Dribbles group. We conclude that DC-Dribbles vaccine has a remarkable efficacy superior to either Dribbles alone or DC alone in the decline of HCC development and survival improvement. IL-10 is a predictive biomarker for response after immunotherapy.

Lupus IgA1 autoantibodies synergize with IgG to enhance plasmacytoid dendritic cell responses to RNA-containing immune complexes.

Autoantibodies to nuclear antigens are hallmarks of systemic lupus erythematosus (SLE) where they contribute to pathogenesis. However, there remains a gap in our knowledge regarding how different isotypes of autoantibodies contribute to this autoimmune disease, including the production of the critical type I interferon (IFN) cytokines by plasmacytoid dendritic cells (pDCs) in response to immune complexes (ICs). We focused on IgA, which is the second-most prevalent isotype in serum and, along with IgG, is deposited in glomeruli in individuals with lupus nephritis. We show that individuals with SLE have serum IgA autoantibodies against most nuclear antigens, correlating with IgG against the same antigen. We investigated whether IgA autoantibodies against a major SLE autoantigen, Smith ribonucleoprotein (Sm/RNP), played a role in IC activation of pDCs. We found that pDCs expressed the IgA-specific Fc receptor, FcαR, and IgA1 autoantibodies synergized with IgG in RNA-containing ICs to generate robust primary blood pDC IFN-α responses in vitro. pDC responses to these ICs required both FcαR and FcγRIIa, showing synergy between these Fc receptors. Sm/RNP IC binding to and internalization by pDCs were greater when ICs contained both IgA1 and IgG. Circulating pDCs from individuals with SLE had higher binding of IgA1-containing ICs and higher expression of FcαR than pDCs from healthy control individuals. Although pDC FcαR expression correlated with the blood IFN-stimulated gene signature in SLE, Toll-like receptor 7 agonists, but not IFN-α, up-regulated pDC FcαR expression in vitro. Together, we show a mechanism by which IgA1 autoantibodies contribute to SLE pathogenesis.

Reactive oxygen species/glutathione dual sensitive nanoparticles with encapsulation of miR155 and curcumin for synergized cancer immunotherapy.

Considerable attention has been directed towards exploring the potential efficacy of miR-155 in the realm of cancer immunotherapy. Elevated levels of miR-155 in dendritic cells (DCs) have been shown to enhance their maturation, migration, cytokine secretion, and their ability to promote T cell activation. In addition, overexpression of mir155 in M2 macrophages boost the polarization towards the M1 phenotype. Conversely, miR-155 has the propensity to induce the accumulation of immunosuppressive cells like regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in the tumor tissue. To account for this discrepancy, it is imperative to get help from a drug that could deal with immunosuppressive effect. Curcumin (CUR) exhibits the capacity to prompt Tregs converse into T helper 1 cells, fostering the polarization of M2 tumor-associated macrophage towards the M1 phenotype, and impeding the recruitment and aggregation of MDSCs within the tumor microenvironment. Nonetheless, CUR is known to exert an immunosuppressive impact on DCs by hindering the expression of maturation markers, cytokines, and chemokines, thereby prevent DCs response to immunostimulatory agents. Hence, a reactive oxygen species/glutathione dual responsive drug conveyance platform (CUR/miR155@DssD-Hb NPs) was devised to co-deliver CUR and miR155, with the aim of exploring their synergistic potential in bolstering a sustained and robust anti-tumor immune response. In vitro and in vivo results have suggested that CUR/miR155@DssD-Hb NPs can effectively inhibit the viability of 4T1 and B16F10 tumor cells, trigger the release of damage associated molecular patterns, stimulate DCs maturation, subsequent activation of CD8+ T cells, diminish immunosuppressive cell populations (MDSCs, Tregs, M2 TAMs and exhausted T cells), promote the formation of long-term immunity and lessen the formation of metastatic nodules in the lungs. In summary, the co-delivery system integrating CUR and miR155 (CUR/miR155@DssD-Hb NPs) demonstrates promise as a promising strategy for the immunotherapy of melanoma and triple negative breast cancer.

A long-term stable cold-chain-friendly HIV mRNA vaccine encoding multi-epitope viral protease cleavage site immunogens inducing immunogen-specific protective T cell immunity.

The lack of success in clinical trials for HIV vaccines highlights the need to explore novel strategies for vaccine development. Research on highly exposed seronegative (HESN) HIV-resistant Kenyan female sex workers revealed naturally protective immunity is correlated with a focused immune response mediated by virus-specific CD8 T cells. Further studies indicated that the immune response is unconventionally focused on highly conserved sequences around HIV viral protease cleavage sites (VPCS). Thus, taking an unconventional approach to HIV vaccine development, we designed lipid nanoparticles loaded with mRNA that encodes multi-epitopes of VPCS (MEVPCS-mRNA LNP), a strategic design to boost antigen presentation by dendritic cells, promoting effective cellular immunity. Furthermore, we developed a novel cold-chain compatible mRNA LNP formulation, ensuring long-term stability and compatibility with cold-chain storage/transport, widening accessibility of mRNA LNP vaccine in low-income countries. The in-vivo mouse study demonstrated that the vaccinated group generated VPCS-specific CD8 memory T cells, both systemically and at mucosal sites of viral entry. The MEVPCS-mRNA LNP vaccine-induced CD8 T cell immunity closely resembled that of the HESN group and displayed a polyfunctional profile. Notably, it induced minimal to no activation of CD4 T cells. This proof-of-concept study underscores the potential of the MEVPCS-mRNA LNP vaccine in eliciting CD8 T cell memory specific to the highly conserved multiple VPCS, consequently having a broad coverage in human populations and limiting viral escape mutation. The MEVPCS-mRNA LNP vaccine holds promise as a candidate for an effective prophylactic HIV vaccine.

Controlled human hookworm infection remodels plasmacytoid dendritic cells and regulatory T cells towards profiles seen in natural infections in endemic areas.

Hookworm infection remains a significant public health concern, particularly in low- and middle-income countries, where mass drug administration has not stopped reinfection. Developing a vaccine is crucial to complement current control measures, which necessitates a thorough understanding of host immune responses. By leveraging controlled human infection models and high-dimensional immunophenotyping, here we investigated the immune remodeling following infection with 50 Necator americanus L3 hookworm larvae in four naïve volunteers over two years of follow-up and compared the profiles with naturally infected populations in endemic areas. Increased plasmacytoid dendritic cell frequency and diminished responsiveness to Toll-like receptor 7/8 ligand were observed in both controlled and natural infection settings. Despite the increased CD45RA+ regulatory T cell (Tregs) frequencies in both settings, markers of Tregs function, including inducible T-cell costimulatory (ICOS), tumor necrosis factor receptor 2 (TNFR2), and latency-associated peptide (LAP), as well as in vitro Tregs suppressive capacity were higher in natural infections. Taken together, this study provides unique insights into the immunological trajectories following a first-in-life hookworm infection compared to natural infections.

Plasmacytoid dendritic cells at the forefront of anti-cancer immunity: rewiring strategies for tumor microenvironment remodeling.

Plasmacytoid dendritic cells (pDCs) are multifaceted immune cells executing various innate immunological functions. Their first line of defence consists in type I interferons (I-IFN) production upon nucleic acids sensing through endosomal Toll-like receptor (TLR) 7- and 9-dependent signalling pathways. Type I IFNs are a class of proinflammatory cytokines that have context-dependent functions on cancer immunosurveillance and immunoediting. In the last few years, different studies have reported that pDCs are also able to sense cytosolic DNA through cGAS-STING (stimulator of interferon genes) pathway eliciting a potent I-IFN production independently of TLR7/9. Human pDCs are also endowed with direct effector functions via the upregulation of TRAIL and production of granzyme B, the latter modulated by cytokines abundant in cancer tissues. pDCs have been detected in a wide variety of human malignant neoplasms, including virus-associated cancers, recruited by chemotactic stimuli. Although the role of pDCs in cancer immune surveillance is still uncompletely understood, their spontaneous activation has been rarely documented; moreover, their presence in the tumor microenvironment (TME) has been associated with a tolerogenic phenotype induced by immunosuppressive cytokines or oncometabolites. Currently tested treatment options can lead to pDCs activation and disruption of the immunosuppressive TME, providing a relevant clinical benefit. On the contrary, the antibody-drug conjugates targeting BDCA-2 on immunosuppressive tumor-associated pDCs (TA-pDCs) could be proposed as novel immunomodulatory therapies to achieve disease control in patients with advance stage hematologic malignancies or solid tumors. This Review integrate recent evidence on the biology of pDCs and their pharmacological modulation, suggesting their relevant role at the forefront of cancer immunity.

Corneal nerve fiber morphology following COVID-19 infection in vaccinated and non-vaccinated population.

To examine corneal subbasal nerve changes in patients who received vaccination against SARS-CoV-2 virus and underwent COVID-19 infection compared to infected non-vaccinated patients and healthy controls. Twenty-nine eyes of 29 vaccinated patients (mean age: 36.66 ± 12.25 years) within six months after PCR or Ag test proven COVID-19 infection and twenty-eight eyes of 28 age-matched infected, non-vaccinated patients (mean age: 42.14 ± 14.17 years) were enrolled. Twenty-five age-matched healthy individuals (mean age: 47.52 ± 18.45 years) served as controls. In vivo confocal microscopy (Heidelberg Retina Tomograph II Rostock Cornea Module, Germany) was performed in each group. Corneal subbasal nerve plexus morphology and corneal dendritic cells (DC) were evaluated. Significantly higher corneal nerve fiber density (P < 0.001), nerve branch density (P < 0.001), nerve fiber length (P < 0.001), total branch density (P = 0.007), nerve fiber area (P = 0.001) and fractal dimension (P < 0.001) values were observed in vaccinated patients after COVID-19 infection compared to the non-vaccinated group. Significantly higher DC density was observed in the non-vaccinated group compared to the control group (P = 0.05). There was a statistically significant difference in the size of mature DCs (P < 0.0001) but the size of immature DCs did not differ significantly among the 3 groups (P = 0.132). Our results suggest that SARS-CoV-2 vaccination may have a protective effect against the complications of COVID-19 disease on the corneal subbasal nerve fibers.

Lactococcus lactis subsp. cremoris YRC3780 modifies function of mesenteric lymph node dendritic cells to modulate the balance of T cell differentiation inducing regulatory T cells.

Introduction: The intestinal immune system plays a pivotal role in the induction of immune responses against food. In the case of T cell response, dendritic cells (DCs) are especially important. However, the regulation of immune responses to food by intestinal DCs has been poorly described. In this study, we analyzed the effect of Lactococcus lactis subsp. cremoris YRC3780, a lactic acid bacterial strain isolated from kefir, a traditional fermented milk product, on the immune responses induced by antigen presentation by intestinal DCs to T cells as well as the mechanism of action of these immunomodulatory effects. It has been shown that L. cremoris YRC3780 ameliorates the symptoms of pollinosis in both animal and human studies. Methods: CD11c+ cells from mesenteric lymph nodes (MLNs) of BALB/c mice were cultured as MLN DCs with L. cremoris YRC3780 and expression of genes inducing regulatory T cells (Tregs) was examined by qPCR. In addition, MLN DCs were cocultured with CD4+ T cells from DO11.10 transgenic mice expressing an ovalbumin (OVA)-specific TCR and the OVA antigen peptide and L. cremoris YRC3780. Induction of Tregs was examined by flow cytometry, gene expression was analyzed by DNA microarray and qPCR, and the production of cytokines was measured by ELISA. MLN DCs from TLR2-deficient mice and components of L. cremoris YRC3780 were used to examine the recognition of YRC3780 by MLN DCs. Results: L. cremoris YRC3780 enhanced the expression of genes involved in Treg induction in MLN DCs and induced Foxp3+CD4+T cells in an MLN DC and CD4+ T-cell co-culture system. The effect on MLN DCs was likely mediated by receptors other than TLR2. Together with microarray analyses of CD4+ T cell gene expression and cytokine ELISA, it was demonstrated that L. cremoris YRC3780 promoted the induction of Th1 and Tregs, and regulated the balance of Th1/Th2 and Treg/Th17 cells involving multiple genes via the antigen-presentation of MLN DCs. Discussion: Our findings provide insights into the modulation of intestinal immune responses mediated by DCs and the antiallergic effects of lactic acid bacteria.

Programming of in Situ Tumor Vaccines via Supramolecular Nanodrug/Hydrogel Composite and Deformable Nanoadjuvant for Cancer Immunotherapy.

The development of in situ tumor vaccines offers promising prospects for cancer treatment. Nonetheless, the generation of plenary autologous antigens in vivo and their codelivery to DC cells along with adjuvants remains a significant challenge. Herein, we developed an in situ tumor vaccine using a supramolecular nanoparticle/hydrogel composite (ANPMTO/ALCD) and a deformable nanoadjuvant (PPER848). The ANPMTO/ALCD composite consisted of ß-cyclodextrin-decorated alginate (Alg-g-CD) and MTO-encapsulated adamantane-decorated nanoparticles (ANPMTO) through supramolecular interaction, facilitating the long-term and sustained production of plenary autologous antigens, particularly under a 660 nm laser. Simultaneously, the produced autologous antigens were effectively captured by nanoadjuvant PPER848 and subsequently transported to lymph nodes and DC cells, benefiting from its optimized size and deformability. This in situ tumor vaccine can trigger a robust antitumor immune response and demonstrate significant therapeutic efficacy in inhibiting tumor growth, suppressing tumor metastasis, and preventing postoperative recurrence, offering a straightforward approach to programming in situ tumor vaccines.

CD150­dependent activation of EBV­transformed B cells induces the differentiation of peripheral blood monocytes via the secretion of multiple cytokines.

CD150, also termed signaling lymphocyte activation molecule family member 1, is a cell surface receptor expressed on T cells, B cells, dendritic cells (DCs) and some tumors. Stimulation of CD150 on immune cells induces cell proliferation and cytokine production. However, the function of CD150 in Epstein­Barr virus (EBV)­infected B cells is still not fully understood. In the present study, CD150 expression on B cells increased rapidly following EBV infection, and various CD150 antibodies, measles viral proteins and recombinant CD150 proteins induced the secretion of multiple cytokines in both CD150+ EBV­transformed B cells and EBV+ lymphoma cells. Notably, the IL­1α protein level showed the greatest increase among all cytokines measured. The culture supernatant containing these cytokines induced the rapid differentiation of monocytes to DCs after only 2 days in vitro, which was faster than the established DC maturation time. Furthermore, knockdown of CD150 expression led to a reduction in the secretion of multiple cytokines, and monocyte differentiation was partially inhibited by anti­IL­1α and anti­granulocyte­macrophage colony­stimulating factor neutralizing antibodies. Collectively, the results of the present study suggest that CD150 activation triggers cytokine production in EBV­transformed B cells, and that measles virus coinfection might affect immune responses through the production of various cytokines in EBV+ lymphoma cells.