High-dimensional analysis of 16 SARS-CoV-2 vaccine combinations reveals lymphocyte signatures correlating with immunogenicity.

The range of vaccines developed against severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) provides a unique opportunity to study immunization across different platforms. In a single-center cohort, we analyzed the humoral and cellular immune compartments following five coronavirus disease 2019 (COVID-19) vaccines spanning three technologies (adenoviral, mRNA and inactivated virus) administered in 16 combinations. For adenoviral and inactivated-virus vaccines, heterologous combinations were generally more immunogenic compared to homologous regimens. The mRNA vaccine as the second dose resulted in the strongest antibody response and induced the highest frequency of spike-binding memory B cells irrespective of the priming vaccine. Priming with the inactivated-virus vaccine increased the SARS-CoV-2-specific T cell response, whereas boosting did not. Distinct immune signatures were elicited by the different vaccine combinations, demonstrating that the immune response is shaped by the type of vaccines applied and the order in which they are delivered. These data provide a framework for improving future vaccine strategies against pathogens and cancer.

Trisomy 21 dysregulates T cell lineages toward an autoimmunity-prone state associated with interferon hyperactivity.

Trisomy 21 (T21) causes Down syndrome (DS), a condition characterized by high prevalence of autoimmune disorders. However, the molecular and cellular mechanisms driving this phenotype remain unclear. Building upon our previous finding that T cells from people with DS show increased expression of interferon (IFN)-stimulated genes, we have completed a comprehensive characterization of the peripheral T cell compartment in adults with DS with and without autoimmune conditions. CD8+ T cells from adults with DS are depleted of naïve subsets and enriched for differentiated subsets, express higher levels of markers of activation and senescence (e.g., IFN-γ, Granzyme B, PD-1, KLRG1), and overproduce cytokines tied to autoimmunity (e.g., TNF-α). Conventional CD4+ T cells display increased differentiation, polarization toward the Th1 and Th1/17 states, and overproduction of the autoimmunity-related cytokines IL-17A and IL-22. Plasma cytokine analysis confirms elevation of multiple autoimmunity-related cytokines (e.g., TNF-α, IL17A-D, IL-22) in people with DS, independent of diagnosis of autoimmunity. Although Tregs are more abundant in DS, functional assays show that CD8+ and CD4+ effector T cells with T21 are resistant to Treg-mediated suppression, regardless of Treg karyotype. Transcriptome analysis of white blood cells and T cells reveals strong signatures of T cell differentiation and activation that correlate positively with IFN hyperactivity. Finally, mass cytometry analysis of 8 IFN-inducible phosphoepitopes demonstrates that T cell subsets with T21 show elevated levels of basal IFN signaling and hypersensitivity to IFN-α stimulation. Therefore, these results point to T cell dysregulation associated with IFN hyperactivity as a contributor to autoimmunity in DS.

High IRF8 expression correlates with CD8 T cell infiltration and is a predictive biomarker of therapy response in ER-negative breast cancer.

BACKGROUND: Characterization of breast cancer (BC) through the determination of conventional markers such as ER, PR, HER2, and Ki67 has been useful as a predictive and therapeutic tool. Also, assessment of tumor-infiltrating lymphocytes has been proposed as an important prognostic aspect to be considered in certain BC subtypes. However, there is still a need to identify additional biomarkers that could add precision in distinguishing therapeutic response of individual patients. To this end, we focused in the expression of interferon regulatory factor 8 (IRF8) in BC cells. IRF8 is a transcription factor which plays a well-determined role in myeloid cells and that seems to have multiple antitumoral roles: it has tumor suppressor functions; it acts downstream IFN/STAT1, required for the success of some therapeutic regimes, and its expression in neoplastic cells seems to depend on a cross talk between the immune contexture and the tumor cells. The goal of the present study was to examine the relationship between IRF8 with the therapeutic response and the immune contexture in BC, since its clinical significance in this type of cancer has not been thoroughly addressed. METHODS: We identified the relationship between IRF8 expression and the clinical outcome of BC patients and validated IRF8 as predictive biomarker by using public databases and then performed in silico analysis. To correlate the expression of IRF8 with the immune infiltrate in BC samples, we performed quantitative multiplex immunohistochemistry. RESULTS: IRF8 expression can precisely predict the complete pathological response to monoclonal antibody therapy or to select combinations of chemotherapy such as FAC (fluorouracil, adriamycin, and cytoxan) in ER-negative BC subtypes. Analysis of immune cell infiltration indicates there is a strong correlation between activated and effector CD8+ T cell infiltration and tumoral IRF8 expression. CONCLUSIONS: We propose IRF8 expression as a potent biomarker not only for prognosis, but also for predicting therapy response in ER-negative BC phenotypes. Its expression in neoplastic cells also correlates with CD8+ T cell activation and infiltration. Therefore, our results justify new efforts towards understanding mechanisms regulating IRF8 expression and how they can be therapeutically manipulated.

In Vivo Visualizing the IFN-ß Response Required for Tumor Growth Control in a Therapeutic Model of Polyadenylic-Polyuridylic Acid Administration.

The crucial role that endogenously produced IFN-ß plays in eliciting an immune response against cancer has recently started to be elucidated. Endogenous IFN-ß has an important role in immune surveillance and control of tumor development. Accordingly, the role of TLR agonists as cancer therapeutic agents is being revisited via the strategy of intra/peritumoral injection with the idea of stimulating the production of endogenous type I IFN inside the tumor. Polyadenylic-polyuridylic acid (poly A:U) is a dsRNA mimetic explored empirically in cancer immunotherapy a long time ago with little knowledge regarding its mechanisms of action. In this work, we have in vivo visualized the IFN-ß required for the antitumor immune response elicited in a therapeutic model of poly A:U administration. In this study, we have identified the role of host type I IFNs, cell populations that are sources of IFN-ß in the tumor microenvironment, and other host requirements for tumor control in this model. One single peritumoral dose of poly A:U was sufficient to induce IFN-ß, readily visualized in vivo. IFN-ß production relied mainly on the activation of the transcription factor IFN regulatory factor 3 and the molecule UNC93B1, indicating that TLR3 is required for recognizing poly A:U. CD11c(+) cells were an important, but not the only source of IFN-ß. Host type I IFN signaling was absolutely required for the reduced tumor growth, prolonged mice survival, and the strong antitumor-specific immune response elicited upon poly A:U administration. These findings add new perspectives to the use of IFN-ß-inducing compounds in tumor therapy.

Krüppel-like factor 6 interferes with cellular transformation induced by the H-ras oncogene.

KLF6 is a member of the Krüppel-like factor family of transcription factors, with diverse roles in the regulation of cell physiology, including proliferation, signal transduction, and apoptosis. Mutations or down-regulation of KLF6 have been described in several human cancers. In this work, we found that KLF6-knockdown resulted in the formation of transformed foci and allowed the spontaneous conversion of NIH3T3 cells to a tumorigenic state. We further assessed the role of KLF6 in the context of oncogenic Ras. We showed that KLF6 was up-regulated by H-Ras(G12V) expression in a Jun N-terminal kinase (JNK)-dependent manner, correlated with enhanced klf6 promoter activity. We found that ectopic KLF6 expression induced a G1-phase cell cycle arrest, thereby decreasing the cell proliferation rate. In addition, constitutive KLF6 expression impaired H-Ras(G12V)-mediated loss of density-dependent growth inhibition and anchorage-independent growth. Moreover, growth of H-Ras(G12V)-driven tumors was reduced in mice challenged with cells stably expressing KLF6. KLF6 expression correlated with the up-regulation of p21, whereas neither p53 induction nor apoptotic cell death was detected. Further, p21 knockdown impaired KLF6-induced cell cycle arrest. These findings provide novel evidence highlighting KLF6 function in response to malignant transformation, suggesting the relevance of KLF6 in controlling cell proliferation and hindering tumorigenesis.

TLR7 triggering with polyuridylic acid promotes cross-presentation in CD8α+ conventional dendritic cells by enhancing antigen preservation and MHC class I antigen permanence on the dendritic cell surface.

ssRNA can interact with dendritic cells (DCs) through binding to TLR7, inducing secretion of proinflammatory cytokines and type I IFN. Triggering TLR7 enhances cross-priming of CD8(+) T cells, which requires cross-presentation of exogenous Ag to DCs. However, how TLR triggering can affect Ag cross-presentation is still not clear. Using OVA as an Ag model, we observed that stimulation of TLR7 in DCs by polyuridylic acid (polyU), a synthetic ssRNA analog, generates a strong specific cytotoxic response in C57BL/6 mice. PolyU stimulate CD8α(+) DCs to cross-prime naive CD8(+) T cells in a type I IFN-dependent fashion. This enhanced cross-priming is accompanied by a higher density of OVA(256-264)/H-2K(b) complexes on CD8α(+) DCs treated with polyU, as well as by upregulation of costimulatory molecules and increased secretion of proinflammatory cytokines by DCs. Cross-priming of CD8(+) T cells by DCs treated with polyU requires proteasome and Ag translocation to cytosol through the Sec61 channel in DCs. The observed enhancement in OVA cross-presentation with polyU in DCs could be mediated by a limited Ag degradation in endophagosomal compartments and a higher permanence of OVA peptide/MHC class I complexes on DCs. These observations clearly reveal that key steps of Ag processing for cross-presentation can be modulated by TLR ligands, opening new avenues for understanding their mechanisms as adjuvants of the immune response.

Direct effect of dsRNA mimetics on cancer cells induces endogenous IFN-ß production capable of improving dendritic cell function.

Viral double-stranded RNA (dsRNA) mimetics have been explored in cancer immunotherapy to promote antitumoral immune response. Polyinosine-polycytidylic acid (poly I:C) and polyadenylic-polyuridylic acid (poly A:U) are synthetic analogs of viral dsRNA and strong inducers of type I interferon (IFN). We describe here a novel effect of dsRNA analogs on cancer cells: besides their potential to induce cancer cell apoptosis through an IFN-ß autocrine loop, dsRNA-elicited IFN-ß production improves dendritic cell (DC) functionality. Human A549 lung and DU145 prostate carcinoma cells significantly responded to poly I:C stimulation, producing IFN-ß at levels that were capable of activating STAT1 and enhancing CXCL10, CD40, and CD86 expression on human monocyte-derived DCs. IFN-ß produced by poly I:C-activated human cancer cells increased the capacity of monocyte-derived DCs to stimulate IFN-γ production in an allogeneic stimulatory culture in vitro. When melanoma murine B16 cells were stimulated in vitro with poly A:U and then inoculated into TLR3(-/-) mice, smaller tumors were elicited. This tumor growth inhibition was abrogated in IFNAR1(-/-) mice. Thus, dsRNA compounds are effective adjuvants not only because they activate DCs and promote strong adaptive immunity, but also because they can directly act on cancer cells to induce endogenous IFN-ß production and contribute to the antitumoral response.

COVID-19 patients display changes in lymphocyte subsets with a higher frequency of dysfunctional CD8lo T cells associated with disease severity.

This work examines cellular immunity against SARS-CoV-2 in patients from Córdoba, Argentina, during two major waves characterized by different circulating viral variants and different social behavior. Using flow cytometry, we evaluated the main lymphocyte populations of peripheral blood from hospitalized patients with moderate and severe COVID-19 disease. Our results show disturbances in the cellular immune compartment, as previously reported in different cohorts worldwide. We observed an increased frequency of B cells and a significant decrease in the frequency of CD3+ T cells in COVID-19 patients compared to healthy donors (HD). We also found a reduction in Tregs, which was more pronounced in severe patients. During the first wave, the frequency of GZMB, CD107a, CD39, and PD-1-expressing conventional CD4+ T (T conv) cells was significantly higher in moderate and severe patients than in HD. During the second wave, only the GZMB+ T conv cells of moderate and severe patients increased significantly. In addition, these patients showed a decreased frequency in IL-2-producing T conv cells. Interestingly, we identified two subsets of circulating CD8+ T cells with low and high CD8 surface expression in both HD and COVID-19 patients. While the percentages of CD8hi and CD8lo T cells within the CD8+ population in HD are similar, a significant increase was observed in CD8lo T cell frequency in COVID-19 patients. CD8lo T cell populations from HD as well as from SARS-CoV-2 infected patients exhibited lower frequencies of the effector cytokine-producing cells, TNF, IL-2, and IFN-γ, than CD8hi T cells. Interestingly, the frequency of CD8lo T cells increased with disease severity, suggesting that this parameter could be a potential marker for disease progression. Indeed, the CD8hi/CD8lo index helped to significantly improve the patient's clinical stratification and disease outcome prediction. Our data support the addition of, at least, a CD8hi/CD8lo index into the panel of biomarkers commonly used in clinical labs, since its determination may be a useful tool with impact on the therapeutic management of the patients.

Different cytokine and chemokine profiles in hospitalized patients with COVID-19 during the first and second outbreaks from Argentina show no association with clinical comorbidities.

Background: COVID-19 severity has been linked to an increased production of inflammatory mediators called "cytokine storm". Available data is mainly restricted to the first international outbreak and reports highly variable results. This study compares demographic and clinical features of patients with COVID-19 from Córdoba, Argentina, during the first two waves of the pandemic and analyzes association between comorbidities and disease outcome with the "cytokine storm", offering added value to the field. Methods: We investigated serum concentration of thirteen soluble mediators, including cytokines and chemokines, in hospitalized patients with moderate and severe COVID-19, without previous rheumatic and autoimmune diseases, from the central region of Argentina during the first and second infection waves. Samples from healthy controls were also assayed. Clinical and biochemical parameters were collected. Results: Comparison between the two first COVID-19 waves in Argentina highlighted that patients recruited during the second wave were younger and showed less concurrent comorbidities than those from the first outbreak. We also recognized particularities in the signatures of systemic cytokines and chemokines in patients from both infection waves. We determined that concurrent pre-existing comorbidities did not have contribution to serum concentration of systemic cytokines and chemokines in COVID-19 patients. We also identified immunological and biochemical parameters associated to inflammation which can be used as prognostic markers. Thus, IL-6 concentration, C reactive protein level and platelet count allowed to discriminate between death and discharge in patients hospitalized with severe COVID-19 only during the first but not the second wave. Conclusions: Our data provide information that deepens our understanding of COVID-19 pathogenesis linking demographic features of a COVID-19 cohort with cytokines and chemokines systemic concentration, presence of comorbidities and different disease outcomes. Altogether, our findings provide information not only at local level by delineating inflammatory/anti-inflammatory response of patients but also at international level addressing the impact of comorbidities and the infection wave in the variability of cytokine and chemokine production upon SARS-CoV-2 infection.

Male rat genital tract infection with Chlamydia muridarum has no significant consequence on male fertility.

PURPOSE: Chlamydia trachomatis infection of the male genital tract was proposed to alter male fertility. We studied the putative consequences of chlamydial male genital tract infection on semen quality and male fertility in an experimental rat model of infection. MATERIALS AND METHODS: We used 36 male and 40 female Wistar rats. Male genital infection was created by inoculating Chlamydia muridarum in the meatal urethra. The presence of C. muridarum was evaluated by polymerase chain reaction in semen and male genital tract organs early (15 days) and late (80 days) after infection. Sperm quality parameters were assayed in seminal and epididymal sperm from sham infected and infected rats. Mating studies with sexually mature females were performed and fertility parameters were assayed, including potency, fecundity and fertility indexes, fetal size, and pre-implantation and post-implantation embryo loss. RESULTS: Male rats showed ascending, disseminated infection 15 days after infection. Bacteria persisted in the prostate and seminal vesicles 80 days after infection. C. muridarum was detected in semen in most rats regardless of acute or chronic infection. Seminal or epididymal sperm quality did not differ in infected and sham infected rats 15 or 80 days after infection. Sperm apoptosis was also minimal in infected rats. No differences were observed in fertility parameters between infected and sham infected rats. CONCLUSIONS: C. muridarum infects the rat male genital tract and persists mainly in the prostate. Although C. muridarum was detected in semen during acute and chronic infection, no alterations in sperm quality were observed. C. muridarum infection does not impair male fertility.

Oral squamous cell carcinoma (OSCC) tumors from heavy alcohol consumers are associated with higher levels of TLR9 and a particular immunophenotype: Impact on patient survival.

Oral squamous cell carcinoma (OSCC) is one of the most frequent types of oral cancer in developing countries and its burden correlates with exposure to tobacco and excessive alcohol consumption. Toll like receptors (TLRs) are major sensors of inflammatory stimuli, from both microbial and sterile causes and as such, they have been related to tumor progression and metastasis. Here, we evaluated the expression of TLR2, 4 and 9 as well as CD3+, CD8+ and Granzyme B+ cell infiltration by immunohistochemistry in oral samples of 30 patients with OSCC, classified according to their consumption of alcohol. Our findings indicate that there is a significant association between heavy alcohol consumption and tumors with higher expression levels of TLR9. Moreover, patients with TLR9high tumors, as well as those who indicated high consumption of alcohol exhibited a diminished overall survival. TCGA data analysis indicated that TLR9high tumors express a significant increase in some genes related with the oral cavity itself, inflammation and tumor promotion. Our analysis of tumor infiltrating leukocytes demonstrated that the major differences perceived in heavy alcohol consumers was the location of CD8+ T cells infiltrating the tumor, which showed lower numbers intratumorally. Our data suggest the existence of a pathogenic loop that involves alcohol consumption, high TLR9 expression and the immunophenotype, which might have a profound impact on the progression of the disease.

Male rodent genital tract infection with Chlamydia muridarum: persistence in the prostate gland that triggers self-immune reactions in genetically susceptible hosts.

PURPOSE: We investigated Chlamydia trachomatis infection and its pathogenic consequences in the male rodent genital tract. MATERIALS AND METHODS: Male rats were inoculated in the meatal urethra with Chlamydia muridarum. We sought bacterial DNA at early and late times after inoculation in different parts of the male genital tract. Histological alterations and the immune response against prostate antigens were analyzed. RESULTS: Male rats showed ascending infection with wide dissemination of bacteria in the genital tract at an early time point after inoculation. At later stages bacteria persisted only in some parts of the genital tract and in the prostate gland. C. muridarum was also detected in semen in a high proportion of rats irrespective of an acute or chronic stage of infection. Histological alterations that accompanied C. muridarum were especially observed in the prostate and mainly composed of CD3+ cell infiltration. Positive humoral and cellular responses against prostate antigens were noted in a considerable number of infected rats. NOD mice, an autoimmune, prostatitis prone strain, showed a similar pattern with C. muridarum in the prostate of 100% of infected mice, which was again accompanied by mononuclear cell infiltration and antibodies against prostate antigens at early and late times after inoculation. CONCLUSIONS: Results reveal that C. muridarum infects the male rodent genitourinary tract with special persistence in the prostate gland, where it causes chronic inflammation that in turn may act as a trigger factor for self-immune reactions in susceptible hosts.

Arthritogenic monoclonal antibodies from K/BxN mice.

Arthritis in the K/BxN mouse model is provoked by pathogenic antibodies (Abs) directed against a ubiquitously expressed protein, glucose-6-phosphate isomerase (GPI). To begin dissecting the repertoire of arthritogenic immunoglobulins (Igs) in the K/BxN model, and to provide a basis for comparison with RA patients we have generated anti-GPI monoclonal Abs (mAbs) from spontaneously activated B cells in the lymphoid organs of arthritic mice. B cell clones with anti-GPI specificities were present at extraordinarily high frequencies in the spleen, and less frequently in other lymphoid organs and in the synovial fluid. None of the anti-GPI mAbs induced arthritis when injected individually into healthy recipients, but most were effective when combined in pairs or larger pools. Arthritogenic combinations depended on mAbs of the IgG1 isotype, which bound to GPI with Kd in the 10(-9) M range, with no indication of cooperative binding between complementing pairs. Pathogenicity was not associated with recognition of a particular epitope, but the ability to form mAb/GPI multimers by simultaneous recognition of different epitopes was clearly required, consistent with the known role of complement and FcRs in this model. Sequence analysis revealed structural similarities amongst the mAbs, indicating that a particular subset of B cells may evade tolerance in K/BxN mice, and that affinity maturation by somatic mutation likely takes place. These results confirm that GPI itself, rather than a cross-reactive molecule, is the target of pathogenic Igs.

Acute inflammation promotes early cellular stimulation of the epithelial and stromal compartments of the rat prostate.

BACKGROUND: It has been proposed that prostatic inflammation plays a pivotal role in the pathophysiology of benign hyperplasia and prostate cancer. However, little information is available about the prostatic reaction to bacterial compounds in vivo. Our aim was therefore to evaluate the early effects of bacterial infection on rat ventral prostate compartments. METHODS: Using a rat model of acute bacterial prostatitis by Escherichia coli, we analyzed the histological and ultrastructural changes in the prostate at 24, 48, and 72 hr postinfection. Prostatic tissues were immunostained for prostatic binding protein (PBP), ACTA2, ErbB1, and ErbB2 receptors, TUNEL, and markers of cell proliferation. Dot and Western blots for PBP, ACTA2, ErbB1, ErbB2, and TGFbeta1 were also performed. RESULTS: The prostatic epithelium became hypertrophied, with increases in PBP and ErbB1 expression at 24 hr postinfection. Moreover, inflammation induced the expression of ErbB2, a receptor strongly involved in carcinogenesis. These alterations were more pronounced at 48 hr, but the epithelium also showed apoptosis and finally atrophy at 72 hr postinfection, with a decrease in PBP and ErbB receptors. Interestingly, the epithelial cells exhibited a high level of proliferation in response to the bacteria. The stromal reaction to acute inflammation was initially characterized by smooth muscle hypertrophy. Afterwards, muscle cells acquired a secretory phenotype, with a reduction in ACTA2 at 72 hr postinfection. CONCLUSIONS: Prostatic inflammation, even at the early stages, promotes atrophic and proliferative changes, and the upregulation of ErbB receptors together with dedifferentiation of smooth muscle cells. These data suggest that repetitive reinfections could lead to uncontrolled growth in the prostate gland.

Cytokines and the immune-neuroendocrine network: What did we learn from infection and autoimmunity?

The initial view of the neuroendocrine-immune communication as the brake of immune activation is changing. Recent evidence suggests that the optimization of the body's overall response to infection could be actually the role of the immune-endocrine network. In gradually more complex organisms, the multiplicity of host-pathogen interfaces forced the development of efficient and protective responses. Molecules such as cytokines and Toll-like receptors (TLRs) are distributed both in the periphery and in the brain to participate in a coordinated adaptive function. When sustained release of inflammatory mediators occurs, as in autoimmune diseases, undesirable pathological consequences become evident with different manifestations and outcomes. Clearly, organisms are not well adapted to that disregulated condition yet, suggesting that additional partners within neuroendocrine-immune interactions might emerge from the evolutionary road.

Expression of Toll-like receptor 4 in the prostate gland and its association with the severity of prostate cancer.

BACKGROUND: Chronic inflammation has been postulated to be an important driving force to prostate carcinoma. Toll-like receptors (TLRs) compose a family of receptors mainly expressed on immune cells. Recently, functional TLRs have been shown to be also expressed in numerous cancer cells, but their significance has only recently begun to be explored. The purpose of this study was to investigate the putative role of TLR4 expression in prostate carcinoma. METHODS: To determine if there is an association between TLR4 expression and the malignancy of the tumor, 35 prostate carcinoma samples showing different Gleason grades were analyzed by immunohistochemistry. Also, to explore the functionality of the receptors expressed on the epithelium, we analyzed the type of cytokine response elicited and the signaling pathways involved after TLR4 triggering in the human prostate adenocarcinoma cell line, DU-145. RESULTS: TLR4 is expressed in the normal prostate gland in both stroma and epithelium. TLR4 expression significantly drops to negative values as the Gleason grade augments in both, stroma and epithelium. Moreover, DU-145 cells also exhibit TLR4 expression and respond to TLR4 agonists, activating the transcription factor NF-kappaB and increasing the expression of pro-inflammatory mediators. Inhibition of the molecular adaptors MyD88 and MAL by overexpression of dominant-negative mutants diminished LPS-induced activation of NF-kappaB, showing that DU-145 cells activate the NF-kappaB through MyD88-dependent signaling pathways. CONCLUSIONS: We hypothesize that TLR4 in prostate cells could synergize with innate immune cells contributing to an eventual inflammatory process, which in genetically prone individuals could promote carcinogenesis. Prostate 69: 1387-1397, 2009. (c) 2009 Wiley-Liss, Inc.

TLR3 Activation of Intratumoral CD103+ Dendritic Cells Modifies the Tumor Infiltrate Conferring Anti-tumor Immunity.

An important challenge in cancer immunotherapy is to expand the number of patients that benefit from immune checkpoint inhibitors (CI), a fact that has been related to the pre-existence of an efficient anti-tumor immune response. Different strategies are being proposed to promote tumor immunity and to be used in combined therapies with CI. Recently, we reported that intratumoral administration of naked poly A:U, a dsRNA mimetic empirically used in early clinical trials with some success, delays tumor growth and prolongs mice survival in several murine cancer models. Here, we show that CD103+ cDC1 and, to a much lesser extent CD11b+ cDC2, are the only populations expressing TLR3 at the tumor site, and consequently could be potential targets of poly A:U. Upon poly A:U administration these cells become activated and elicit profound changes in the composition of the tumor immune infiltrate, switching the immune suppressive tumor environment to anti-tumor immunity. The sole administration of naked poly A:U promotes striking changes within the lymphoid compartment, with all the anti-tumoral parameters being enhanced: a higher frequency of CD8+ Granzyme B+ T cells, (lower Treg/CD8+ ratio) and an important expansion of tumor-antigen specific CD8+ T cells. Also, PD1/PDL1 showed an increased expression indicating that neutralization of this axis could be exploited in combination with poly A:U. Our results shed new light to promote further assays in this dsRNA mimetic to the clinical field.

Photodynamic Modulation of Type 1 Interferon Pathway on Melanoma Cells Promotes Dendritic Cell Activation.

The immune response against cancer generated by type-I-interferons (IFN-1) has recently been described. Exogenous and endogenous IFN-α/ß have an important role in immune surveillance and control of tumor development. In addition, IFN-1s have recently emerged as novel DAMPs for the consecutive events connecting innate and adaptive immunity, and they also have been postulated as an essential requirement for induction of immunogenic cell death (ICD). In this context, photodynamic therapy (PDT) has been previously linked to the ICD. PDT consists in the administration of a photosensitizer (PS) and its activation by irradiation of the affected area with visible light producing excitation of the PS. This leads to the local generation of harmful reactive oxygen species (ROS) with limited or no systemic defects. In the current work, Me-ALA inducing PpIX (endogenous PS) was administrated to B16-OVA melanoma cells. PpIX preferentially localized in the endoplasmic reticulum (ER). Subsequent PpIX activation with visible light significantly induced oxidative ER-stress mediated-apoptotic cell death. Under these conditions, the present study was the first to report the in vitro upregulation of IFN-1 expression in response to photodynamic treatment in melanoma. This IFN-α/ß transcripts upregulation was concurrent with IRF-3 phosphorylation at levels that efficiently activated STAT1 and increased ligand receptor (cGAS) and ISG (CXCL10, MX1, ISG15) expression. The IFN-1 pathway has been identified as a critical molecular pathway for the antitumor host immune response, more specifically for the dendritic cells (DCs) functions. In this sense, PDT-treated melanoma cells induced IFN-1-dependent phenotypic maturation of monocyte-derived dendritic cells (DCs) by enhancing co-stimulatory signals (CD80, MHC-II) and tumor-directed chemotaxis. Collectively, our findings showed a new effect of PDT-treated cancer cells by modulating the IFN-1 pathway and its impact on the activation of DCs, emphasizing the potential relevance of PDT in adoptive immunotherapy protocols.

Autoimmune etiology in chronic prostatitis syndrome: an advance in the understanding of this pathology.

The prostate is the target of many inflammatory and neoplastic disorders that affect men of all ages. Pathological conditions of the prostate gland range from infection of this organ by ascending bacteria from infected urine, to chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) of a still unknown etiology (accompanied with inflammation and lymphocyte infiltration of the gland), to benign hyperplasia and cancer. Patients under 50 years of age usually suffer from CP/CPPS, a chronic inflammatory syndrome characterized by pelvic pain, irritative voiding symptoms, and sexual dysfunction complaints. In this review, we summarize the current knowledge regarding immunological alterations present in CP/ CPPS patients. Remarkably, an inflammation state, in the absence of an invading infectious agent, is established in these patients, suggesting that an autoimmune process could be involved. In fact, specific autoimmune response to prostate antigens has recently been reported in CP/CPPS patients. Autoimmune response to prostate gland affects the seminal quality reported in these patients and may have critical consequences in their fertility. It is anticipated that preclinical studies in experimental models for CP/CPSS will provide important insights into the etiopathogenic mechanisms involved in this disease. We discuss here the similarities and the differences between human disease and experimental models and argue for the importance of the prostate gland in male reproductive function. Ultimately, we suggest that a state of inflammation, originally incited by an autoimmune response within the prostate, together with a diminished prostate functionality, may compromise male fertility.