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Although many studies have explored the depletion of tumor-associated macrophages (TAM) as a therapeutic strategy for solid tumors, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent (“OximUNO”) that specifically targets CD206+ TAMs and demonstrated efficacy in a triple-negative breast cancer (TNBC) mouse model. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In the TNBC model, a fluorescently labeled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumor lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (indicating immunomodulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent a novel design of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate.Significance:A peptide-targeted nanoformulation of DOX exclusively eliminates mannose receptor+ TAMs in breast cancer models, generating response without off-target effects (a drawback of many TAM-depleting agents under clinical study).

One .docx word file containing the following information:Scheme S1. Synthetic approach for St-PGA-OG-mUNO.Scheme S2. Synthetic approach for OximUNO.Video S1. Fifty ns MD trajectory of St-PGA in solution.Table S1. St-PGA-OG-mUNO and St-PGA-OG dye loading, mUNO loading, size and charge.Table S2. OximUNO and St-PGA-DOX drug loading, mUNO loading, size and charge.Table S3. Hepatic and renal toxicity analysed following one dose of OximUNO.Fig. S1. Representative characterisation of St-PGA-OG and St-PGA-OG-mUNO.Fig. S2. The angle used to characterise the rotation of mUNO around PGA.Fig. S3. St-PGA-OG-mUNO shows low hepatic accumulation in the orthotopic TNBC.Fig. S4. Immunostaining showing CD206 expression in the liver compared to the saturated signal of CD206 in the orthotopic 4T1 tumour.Fig. S5. Immunostaining of endogenous IgG indicates leaky tumour vasculature in the orthotopic 4T1 tumours.Fig. S6. Distribution of St-PGA-OG-mUNO in the lung, spleen, sentinel lymph node (SLN) and kidney.Fig. S7. St-PGA-OG-mUNO shows low hepatic accumulation in the experimental metastasis of TNBC.Fig. S8. St-PGA-OG-mUNO shows higher receptor colocalisation than FAM-mUNO.Fig. S9. St-PGA-OG-mUNO shows high homing to M2 TAMs in the orthotopic TNBC but higher hepatic accumulation with a higher dose.Fig. S10. Representative characterisation of St-PGA-DOX and OximUNO.Fig. S11. LC-MS method development for the determination of DOX in drug release studies and stability studies of OximUNO in i.p. fluid and dPBS.Fig. S12. OximUNO shows no signs of hepatic or renal toxicity.Fig. S13. H&E on healthy Balb/c mouse lung.Fig. S14. Localisation of St-PGA-OG/St-PGA-OG-mUNO and tumour vessels.Fig. S15. H&E staining of hearts from the treatment of orthotopic TNBC.Fig. S16. A repetition of OximUNO treatment on the orthotopic TNBC monitoring tumour growth and survival.Fig. S17. Flow cytometry plots for M2 and M1 macrophages.Fig. S18. Flow cytometry gating for cytotoxic T lymphocytes (CTLs).Fig. S19. Flow cytometry gating for T regulatory cells (Tregs). Fig. S20. Flow cytometry analysis showing total cells.Fig. S21. Treatment with OximUNO does not affect splenic macrophages.

Tables S2 & S3, Legends, and Supplementary Methods from Primary Cutaneous T-Cell Lymphomas Show a Deletion or Translocation Affecting NAV3, the Human UNC-53 Homologue

Supplementary Figure S7 from Primary Cutaneous T-Cell Lymphomas Show a Deletion or Translocation Affecting NAV3, the Human UNC-53 Homologue

Multicolor fluorescent in situ hybridization (FISH) was used to identify acquired chromosomal aberrations in 12 patients with mycosis fungoides or Sézary syndrome, the most common forms of primary cutaneous T-cell lymphoma (CTCL). The most frequently affected chromosome was 12, which showed clonal deletions or translocations with a break point in 12q21 or 12q22 in five of seven consecutive Sézary syndrome patients and a clonal monosomy in the sixth patient. The break point of a balanced translocation t(12;18)(q21;q21.2), mapped in the minimal common region of two deletions, fine mapped to 12q2. By locus-specific FISH, the translocation disrupted one gene, NAV3 (POMFIL1), a human homologue of unc-53 in Caenorhabditis elegans. A missense mutation in the remaining NAV3 allele was found in one of six cases with a deletion or translocation. With locus-specific FISH, NAV3 deletions were found in the skin lesions of four of eight (50%) patients with early mycosis fungoides (stages IA-IIA) and in the skin or lymph node of 11 of 13 (85%) patients with advanced mycosis fungoides or Sézary syndrome. Preliminary functional studies with lentiviral small interfering RNA-based NAV3 silencing in Jurkat cells and in primary lymphocytes showed enhanced interleukin 2 expression (but not CD25 expression). Thus, NAV3 may contribute to the growth, differentiation, and apoptosis of CTCL cells as well as to the skewing from Th1-type to Th2-type phenotype during disease progression. NAV3, a novel putative haploinsufficient tumor suppressor gene, is disrupted in most cases of the commonest types of CTCL and may thus provide a new diagnostic tool.

Supplementary Figures S8 & S9 from Primary Cutaneous T-Cell Lymphomas Show a Deletion or Translocation Affecting NAV3, the Human UNC-53 Homologue

The core function of the immune response is to distinguish between self and foreign. The multiorgan human autoimmune disease, autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED/autoimmune polyendocrine syndrome type 1) is an example of what happens in the body when central immune tolerance goes astray. APECED revealed the existence and function of the autoimmune regulator gene, which has a central role in the development of tolerance. The discovery of autoimmune regulator was the start of a new period in immunology and in understanding the role of central and peripheral tolerance, also very relevant to many skin diseases as we highlight in this review.

Understanding the longevity of antibodies against SARS-CoV-2 infection is of utmost importance in predicting the further course of the pandemic and to plan vaccination strategies. Here we report a cohort of COVID-19 patients with different disease severities whose antibody dynamics we evaluated during one-year of follow-up.We conducted a longitudinal study of 123 COVID-19 patients and 45 SARS CoV-2 negative outpatients with upper respiratory tract infection. We analyzed the demographic and clinical features of the patients with COVID-19 in relation to different disease severities according to the WHO classification. The antibody response was evaluated by a Luciferase Immunoprecipitation System (LIPS) assay at 3, 6, and 12 months after the acute infection.Amongst the enrolled COVID-19 patients, 15 (12%) had mild, 42 (34%) had moderate, 39 (32%) had severe and 27 (22%) had critical disease courses; 79% of the patients were hospitalized. During follow-up, all patients had anti-SARS RBD-IgG levels above the cut-off value on all visits, but the antibody levels varied significantly between the different disease severity groups. Between the six- and 12-month follow-up visits, 41% of patients were vaccinated, which enhanced their antibody levels significantly.Our data demonstrate sustained antibody levels at one-year after moderate and severe COVID-19 infection. Vaccination of patients with the mild disease is important to raise the antibody levels to a protective level.

Epigenetic changes at specific genetic loci and the activation of transcriptional repressor FOXP3 are needed to establish and maintain the regulatory T cell (Treg) lineage. Here we studied the DNA methylation profiles in CD4+CD25+Tregs and CD4+CD25−conventional T cells (Tconvs) from healthy individuals and identified a wide range of differentially methylated CpG sites (DMPs). Overall, Tregs had more hypomethylated DMPs and contained more CpG sites, which on the cell population level were less defined in their methylation status. We identified top hypomethylated CpGs in Tregs close to CENPM, IKZF2, and LYST and hypermethylated sites at the THEMIS, SCML4, and ADD3 genes. Among others, DMPs were enriched for the transcriptional repressor Kaiso binding motifs. Interestingly, in Tregs we found hypomethylation and increased expression of the TSHR gene, which is a risk gene for Graves’ disease (GD). However, subsequent DNA methylation profiling in healthy individuals and GD patients revealed only 19 DMPs and no change at the TSHR locus, indicating that Tregs in GD patients share a similar methylation pattern with healthy controls. Together, we show Treg-specific hypomethylation and expression of the TSHR gene, prompting additional scenarios to explain the genetic link and role of anti-TSHR autoantibodies in GD.

International audience; Background: Immune homeostasis requires fully functional Tregs with a stable phenotype to control autoimmunity. Although IL-34 is a cytokine first described as mainly involved in monocyte cell survival and differentiation, we recently described its expression by CD8+ Tregs in a rat model of transplantation tolerance and by activated FOXP3+ CD4+ and CD8+ Tregs in human healthy individuals. However, its role in autoimmunity and potential in human diseases remains to be determined.Methods: We generated Il34-/- rats and using both Il34-/- rats and mice, we investigated their phenotype under inflammatory conditions. Using Il34-/- rats, we further analyzed the impact of the absence of expression of IL-34 for CD4+ Tregs suppressive function. We investigated the potential of IL-34 in human disease to prevent xenogeneic GVHD and human skin allograft rejection in immune humanized immunodeficient NSG mice. Finally, taking advantage of a biocollection, we investigated the correlation between presence of IL-34 in the serum and kidney transplant rejection.Results: Here we report that the absence of expression of IL-34 in Il34-/- rats and mice leads to an unstable immune phenotype, with production of multiple auto-antibodies, exacerbated under inflammatory conditions with increased susceptibility to DSS- and TNBS-colitis in Il34-/- animals. Moreover, we revealed the striking inability of Il34-/- CD4+ Tregs to protect Il2rg-/- rats from a wasting disease induced by transfer of pathogenic cells, in contrast to Il34+/+ CD4+ Tregs. We also showed that IL-34 treatment delayed EAE in mice as well as GVHD and human skin allograft rejection in immune humanized immunodeficient NSG mice. Finally, we show that presence of IL-34 in the serum is associated with a longer rejection-free period in kidney transplanted patients.Conclusion: Altogether, our data emphasize on the crucial necessity of IL-34 for immune homeostasis and for CD4+ Tregs suppressive function. Our data also shows the therapeutic potential of IL-34 in human transplantation and auto-immunity.Highlights: -Absence of expression of IL-34 in Il34-/- rats and mice leads to an unstable immune phenotype, with a production of multiple auto-antibodies and exacerbated immune pathology under inflammatory conditions. -Il34-/- CD4+ Tregs are unable to protect Il2rg-/- rats from colitis induced by transfer of pathogenic cells. -IL-34 treatment delayed EAE in mice, as well as acute GVHD and human skin allograft rejection in immune-humanized immunodeficient NSG mice.

Immune homeostasis requires fully functional Tregs with a stable phenotype to control autoimmunity. Although IL-34 is a cytokine first described as mainly involved in monocyte cell survival and differentiation, we recently described its expression by CD8+ Tregs in a rat model of transplantation tolerance and by activated FOXP3+ CD4+ and CD8+ Tregs in human healthy individuals. However, its role in autoimmunity and potential in human diseases remain to be determined. Here we report that the absence of expression of IL-34 in Il34-/- rodents leads to an unstable phenotype, with production of multiple auto-antibodies, exacerbated under inflammatory conditions with increased susceptibility to DSS- and TNBS-colitis in deficient animals. Moreover, we strikingly revealed the inability of Il34-/- CD4+ Tregs to protect Il2rg-/- rats from a wasting disease induced by transfer of pathogenic cells, in contrast to Il34+/+ CD4+ Tregs. We also showed that IL-34 treatment delayed EAE in mice as well as GVHD and human skin allograft rejection in immune humanized immunodeficient NSG mice. Finally, we show that presence of IL-34 in the serum is associated with a longer rejection-free period in kidney transplanted patients. Altogether, our data emphasize on the crucial necessity of IL-34 for immune homeostasis and for CD4+ Tregs suppressive function. Our data also shows the therapeutic potential of IL-34 in human transplantation and auto-immunity.

Aire allows medullary thymic epithelial cells (mTECs) to express and present a large number of self‐antigens for central tolerance. Although mTECs express a high diversity of self‐antigen splice isoforms, the extent and regulation of alternative splicing events (ASEs) in their transcripts, notably in those induced by Aire, is unknown. In contrast to Aire‐neutral genes, we find that transcripts of Aire‐sensitive genes show only a low number of ASEs in mTECs, with about a quarter present in peripheral tissues excluded from the thymus. We identify Raver2, as a splicing‐related factor overexpressed in mTECs and dependent on H3K36me3 marks, that promotes ASEs in transcripts of Aire‐neutral genes, leaving Aire‐sensitive ones unaffected. H3K36me3 profiling reveals its depletion at Aire‐sensitive genes and supports a mechanism that is preceding Aire expression leading to transcripts of Aire‐sensitive genes with low ASEs that escape Raver2‐induced alternative splicing. The lack of ASEs in Aire‐induced transcripts would result in an incomplete Aire‐dependent negative selection of autoreactive T cells, thus highlighting the need of complementary tolerance mechanisms to prevent activation of these cells in the periphery.

The high number of mutations in the Omicron variant of SARS-CoV-2 cause its immune escape when compared to the earlier variants of concern (VOC). At least three vaccine doses are required for the induction of Omicron neutralizing antibodies and further reducing the risk for hospitalization. However, most of the studies have focused on the immediate response after the booster vaccination while the duration of immune response is less known. We here studied longitudinal serum samples from the vaccinated individuals up to three months after their third dose of the BNT162b2 vaccine for their capacity to produce protective antibodies and T cell responses to Wuhan and Omicron variants. After the second dose, the antibody levels to the unmutated spike protein were significantly decreased at three months, and only 4% of the individuals were able to inhibit Omicron spike interaction compared to 47%, 38%, and 14% of individuals inhibiting wild-type, delta, and beta variants’ spike protein. Nine months after the second vaccination, the antibody levels were similar to the levels before the first dose and none of the sera inhibited SARS-CoV-2 wild-type or any of the three VOCs. The booster dose remarkably increased antibody levels and their ability to inhibit all variants. Three months after the booster the antibody levels and the inhibition activity were trending lower but still up and not significantly different from their peak values at two weeks after the third dose. Although responsiveness towards mutated spike peptides was lost in less than 20 % of vaccinated individuals, the wild-type spike-specific CD4+ and CD8+ memory T cells were still present at three months after the booster vaccination in the majority of studied individuals. Our data show that two doses of the BNT62b2 vaccine are not sufficient to protect against the Omicron variant, however, the spike-specific antibodies and T cell responses are strongly elicited and well maintained three months after the third vaccination dose.

Although many studies have explored the depletion of tumor-associated macrophages (TAM) as a therapeutic strategy for solid tumors, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent (“OximUNO”) that specifically targets CD206+ TAMs and demonstrated efficacy in a triple-negative breast cancer (TNBC) mouse model. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In the TNBC model, a fluorescently labeled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumor lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (indicating immunomodulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent a novel design of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate. Significance: A peptide-targeted nanoformulation of DOX exclusively eliminates mannose receptor+ TAMs in breast cancer models, generating response without off-target effects (a drawback of many TAM-depleting agents under clinical study).

Although many studies have explored the depletion of tumour-associated macrophages (TAMs) as a therapeutic strategy for solid tumours, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent (“OximUNO”) that specifically targets CD206+ TAMs and demonstrated efficacy in triple negative breast cancer (TNBC) mouse models. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In TNBC models, a fluorescently labelled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumour lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (demonstrating immunostimulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent the first report of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate.

Although many studies have explored the depletion of tumour-associated macrophages (TAMs) as a therapeutic strategy for solid tumours, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent ("OximUNO") that specifically targets CD206+ TAMs and demonstrated efficacy in triple negative breast cancer (TNBC) mouse models. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In TNBC models, a fluorescently-labelled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumour lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (demonstrating immunostimulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent the first report of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate.

The Ikaros family transcription factors regulate lymphocyte development. Loss-of-function variants in

Background Anti-inflammatory (M2) tumour-associated macrophages (TAMs) exert protumoural roles through angiogenesis, immunosuppression and resistance to therapies.1 M2 TAMs express the mannose receptor, CD206,2 excellent marker for targeted therapies. We have previously identified a peptide called mUNO2 that specifically binds to CD206 on M2 TAMs. Aiming to dissect the role of CD206high M2 TAMs in the tumour progression and immunosuppression, we depleted them using an mUNO and doxorubicin (Adriamycin®)-containing polymer-drug nanoconjugate (St-PGA-DOX-mUNO, ‘OximUNO’) where the polymer backbone is branched polyglutamic acid (St-PGA).3 Materials and Methods We compared OximUNO with free DOX and the untargeted nanoconjugate St-PGA-DOX. To study the in vitro cytotoxicity of the nanoconjugates, we used M2 and M1 skewed macrophages derived from human blood buffy coat. To study the in vivo homing of nanoconjugates we used an orthotopic triple negative breast cancer (TNBC, 4T1 cells) model and a TNBC experimental metastases model in immunocompetent mice. For in vivo therapeutic efficacy studies, we used orthotopic and experimental metastases models of TNBC, and administered the compounds intraperitoneally (i.p.). Results In vitro, OximUNO showed 39% higher toxicity to the primary human M2 macrophages than St-PGA-DOX, and 31% lower toxicity to the M1 macrophages than St-PGA-DOX. In vivo, OximUNO showed no change in creatinine or alanine aminotransferase values, indicating no toxic effects to the kidneys or liver. Compared to control St-PGA, i.p.-administered St-PGA-mUNO, showed improved homing to M2 TAMs in both orthotopic and experimental metastases models with low accumulation in the liver. In the orthotopic treatment study, only OximUNO significantly reduced the tumour volume and showed 56% and 38% less lung metastases than DOX and St-PGA-DOX, respectively. Additionally, DOX and St-PGA-DOX produced a significant bodyweight loss whereas OximUNO did not. Importantly, OximUNO treatment resulted in 2-5-fold increase in the ratio of CD8+/FOXP3+ expression, suggesting a shift in the immune landscape towards an immunostimulatory profile. In the experimental metastases model, OximUNO monotherapy resulted in the highest reduction of lung metastases, and this effect correlated with a significant reduction in CD206high M2 TAMs; whereas no significant effect on M2 TAMs population was observed with DOX or untargeted nanoconjugate. Conclusions Our data suggests that the elimination of CD206high M2 TAMs with OximUNO suppresses spontaneous and experimental metastases in safe manner, shifts immune landscape towards immunostimulatory and could therefore be a potential treatment option for TNBC patients. References Hughes R, Qian B-Z, Rowan C, Muthana M, Keklikoglou I, Olson OC, et al. Perivascular M2 macrophages stimulate tumor relapse after chemotherapy. Cancer Res 2015;75(17):3479–91. Scodeller P, Simon-Gracia L, Kopanchuk S, Tobi A, Kilk K, Saalik P, et al. Precision targeting of tumor macrophages with a CD206 binding peptide. Sci Rep 2017;7(1):14655. Duro-Castano A, Nebot VJ, Nino-Pariente A, Arminan A, Arroyo-Crespo JJ, Paul A, et al. Capturing ‘extraordinary’ soft-assembled charge-like polypeptides as a strategy for nanocarrier design. Adv Mater 2017;29(39):1702888. Disclosure Information A. Lepland: None. A. Malfanti: None. U. Haljasorg: None. S. Dordevic: None. L. Salumae: None. P. Peterson: None. T. Teesalu: None. M.J. Vicent: None. P. Scodeller: None.

Background SARS-CoV-2 mRNA vaccines have proven high efficacy, however, limited data exists on the duration of immune responses and their relation to age and side effects. Methods We studied the antibody and memory T cell responses after the two-dose BNT162b2 vaccine in 122 volunteers up to 6 months and correlated the findings with age and side effects. Findings We found a robust antibody response to Spike protein after the second dose. However, the antibody levels declined at 12 weeks and 6 months post-vaccination, indicating a waning of the immune response over time. At 6 months after the second dose, the Spike antibody levels were similar to the levels in persons vaccinated with one dose or in COVID-19 convalescent individuals. The antibodies efficiently blocked ACE2 receptor binding to SARS-CoV-2 Spike protein of five variants of concern at one week but this was decreased at three months. 87% of individuals developed Spike-specific memory T cell responses, which were lower in individuals with increased proportions of immunosenescent CD8+ TEMRA cells. We found antibody response to correlate negatively with age and positively with the total score of vaccination side effects. Interpretation The mRNA vaccine induces a strong antibody response to SARS-CoV-2 and five VOCs at 1 week post-vaccination that decreases thereafter. T cell responses, although detectable in the majority, were lower in individuals with higher T cell immunosenescence. The deterioration of vaccine response suggests the need to monitor for the potential booster vaccination.

The IKAROS family transcription factors regulate lymphocyte development. Loss-of-function variants in IKZF1 cause primary immunodeficiency, but IKAROS family members IKZF2 and IKZF3 have not yet been associated with immunodeficiency yet. Here, we describe a pedigree with a heterozygous truncating variant in IKZF2, encoding the translational activator and repressor HELIOS which is highly expressed in regulatory T cells and effector T cells, particularly of the CD8+ T cell lineage. Protein-protein interaction analysis revealed that the variant abolished HELIOS dimerizations as well as binding to members of the Mi-2/NuRD chromatin remodeling complex. Patients carrying the IKZF2 variant presented with a combined immunodeficiency phenotype characterized by recurrent upper respiratory infections, thrush and mucosal ulcers, as well as chronic lymphadenopathy. With extensive immunophenotyping, functional assays, and transcriptional analysis we show that reduced HELIOS expression was associated with chronic T cell activation and increased production of pro-inflammatory cytokines both in effector and regulatory T cells. Lymph node histology from patients indicated dysregulated germinal center reactions. Moreover, affected individuals displayed profoundly reduced circulating MAIT cell numbers. In summary, we show that this novel loss-of-function variant in HELIOS leads to an immunodeficiency with signs of immune overactivation.One sentence summaryTruncating variant of HELIOS causes immunodeficiency with signs of immune overactivation.

Chemotherapy is the standard of care for patients with triple negative breast cancer (TNBC), an aggressive breast cancer subtype with a poor prognosis. In many solid tumours, M2-skewed tumour-associated macrophages (TAMs) are known to promote progression, immunosuppression, relapse, and dissemination of the malignant disease. Although TAM depletion has been explored as an anticancer strategy, the currently available TAM depleting compounds suffer from poor efficacy and dose-limiting side effects. Here, we develop of a novel TAM-depleting agent that specifically targets CD206+ macrophages and show that it is efficacious as an anti-TNBC agent and well tolerated. This new TAM-depleting compound, called “OximUNO”, is a star-shaped polyglutamate decorated with the CD206-targeting peptide mUNO and carrying doxorubicin through a pH-responsive linker. In the orthotopic and experimental metastases of TNBC, fluorescent reporter mUNO-guided polyglutamate construct homed to CD206+ macrophages in the primary cancer lesions and at the sites of metastases. OximUNO displayed enhanced cytotoxicity towards primary M2 macrophages in vitro and exhibited no acute liver or kidney toxicity in vivo. In TNBC mouse models, OximUNO reduced the progression of primary breast cancer lesions and metastatic dissemination of malignant cells. Treatment with OximUNO had an immunomodulatory effect on the tumour microenvironment: besides reducing the number of CD206+ TAMs, it resulted in increased ratio of the CD8/FOXP3 expression. These studies suggest the potential utility of OximUNO based CD206+ TAM depletion strategies for the treatment of TNBC, and possibly, other types of solid tumours.

Purpose In Estonia, during the first wave of COVID-19 total number of cases confirmed by PCR was 13.3/10,000, similar in most regions, including capital Tallinn, but in the hotspot of Estonian epidemic, an island Saaremaa, the cumulative incidence was 166.1/10,000. We aimed to determine the prevalence of SARS-CoV-2 IgG antibodies in these two regions, symptoms associated with infection and factors associated with antibody concentrations. Methods Participants were selected using stratified (formed by age decades) random sampling and recruited by general practitioners. IgG or neutralizing antibodies were determined from sera by four assays. Symptoms associated with seropositivity were analyzed by multiple correspondence analysis, antibody concentrations by multiple linear regression. Results Total of 3608 individual were invited and 1960 recruited from May 8 to July 31, 2020. Seroprevalence was 1.5% (95% confidence interval (CI) 0.9–2.5) and 6.3% (95% CI 5.0–7.9), infection fatality rate 0.1% (95% CI 0.0–0.2) and 1.3% (95% CI 0.4–2.1) in Tallinn and Saaremaa, respectively. Of seropositive subjects 19.2% (14/73) had acute respiratory illness. Fever, diarrhea and the absence of cough and runny nose were associated with seropositivity in individuals aged 50 or more years. IgG, but not neutralizing antibodies concentrations were higher if fever, difficulty breathing, shortness of breath, chest pain or diarrhea was present, or hospitalization required. Conclusion Similarly to other European countries the seroprevalence of SARS-CoV-2 in Estonia was low even in the hotspot region Saaremaa suggesting that majority of population is susceptible to SARS-CoV-2. Focusing only on respiratory symptoms may delay accurate diagnosis of SARS-CoV-2 infection.

Circulating autoantibodies (auto-Abs) neutralizing high concentrations (10 ng/mL, in plasma diluted 1 to 10) of IFN-α and/or -ω are found in about 10% of patients with critical COVID-19 pneumonia, but not in subjects with asymptomatic infections. We detect auto-Abs neutralizing 100-fold lower, more physiological, concentrations of IFN-α and/or -ω (100 pg/mL, in 1/10 dilutions of plasma) in 13.6% of 3,595 patients with critical COVID-19, including 21% of 374 patients80 years, and 6.5% of 522 patients with severe COVID-19. These antibodies are also detected in 18% of the 1,124 deceased patients (aged 20 days-99 years; mean: 70 years). Moreover, another 1.3% of patients with critical COVID-19 and 0.9% of the deceased patients have auto-Abs neutralizing high concentrations of IFN-β. We also show, in a sample of 34,159 uninfected subjects from the general population, that auto-Abs neutralizing high concentrations of IFN-α and/or -ω are present in 0.18% of individuals between 18 and 69 years, 1.1% between 70 and 79 years, and 3.4%80 years. Moreover, the proportion of subjects carrying auto-Abs neutralizing lower concentrations is greater in a subsample of 10,778 uninfected individuals: 1% of individuals70 years, 2.3% between 70 and 80 years, and 6.3%80 years. By contrast, auto-Abs neutralizing IFN-β do not become more frequent with age. Auto-Abs neutralizing type I IFNs predate SARS-CoV-2 infection and sharply increase in prevalence after the age of 70 years. They account for about 20% of both critical COVID-19 cases in the over-80s, and total fatal COVID-19 cases.

Posté sur medRxiv le 07/04/2021Referred to byAntibodies against type I IFN: The bad guys self-restrain in systemic lupus erythematosusCell Reports Medicine, Volume 4, Issue 1, 17 January 2023, Pages 100903Simon Fillatreau; International audience; Systemic lupus erythematosus (SLE) is characterized by increased expression of type I interferon (IFN)-regulated genes in 50%-75% of patients. We report that out of 501 patients with SLE analyzed, 73 (14%) present autoantibodies against IFNα (anti-IFN-Abs). The presence of neutralizing-anti-IFN-Abs in 4.2% of patients inversely correlates with low circulating IFNα protein levels, inhibition of IFN-I downstream gene signatures, and inactive global disease score. Hallmarks of SLE pathogenesis, including increased immature, double-negative plasmablast B cell populations and reduction in regulatory B cell (Breg) frequencies, were normalized in patients with neutralizing anti-IFN-Abs compared with other patient groups. Immunoglobulin G (IgG) purified from sera of patients with SLE with neutralizing anti-IFN-Abs impedes CpGC-driven IFNα-dependent differentiation of B cells into immature B cells and plasmablasts, thus recapitulating the neutralizing effect of anti-IFN-Abs on B cell differentiation in vitro. Our findings highlight a role for neutralizing anti-IFN-Abs in controlling SLE pathogenesis and support the use of IFN-targeting therapies in patients with SLE lacking neutralizing-anti-IFN-Abs.