Laura Piñero Páez

Abstract Infectious, inflammatory and autoimmune conditions present differently in males and females. SARS-CoV-2 infection in naive males is associated with increased risk of death, whereas females are at increased risk of long COVID 1 , similar to observations in other infections 2 . Females respond more strongly to vaccines, and adverse reactions are more frequent 3 , like most autoimmune diseases 4 . Immunological sex differences stem from genetic, hormonal and behavioural factors 5 but their relative importance is only partially understood 6–8 . In individuals assigned female sex at birth and undergoing gender-affirming testosterone therapy (trans men), hormone concentrations change markedly but the immunological consequences are poorly understood. Here we performed longitudinal systems-level analyses in 23 trans men and found that testosterone modulates a cross-regulated axis between type-I interferon and tumour necrosis factor. This is mediated by functional attenuation of type-I interferon responses in both plasmacytoid dendritic cells and monocytes. Conversely, testosterone potentiates monocyte responses leading to increased tumour necrosis factor, interleukin-6 and interleukin-15 production and downstream activation of nuclear factor kappa B-regulated genes and potentiation of interferon-γ responses, primarily in natural killer cells. These findings in trans men are corroborated by sex-divergent responses in public datasets and illustrate the dynamic regulation of human immunity by sex hormones, with implications for the health of individuals undergoing hormone therapy and our understanding of sex-divergent immune responses in cisgender individuals.

PURPOSE: A causal role of type-I interferons (IFN-I) in autoinflammatory type-I interferonopathies such as SAVI (STING-associated vasculopathy with onset in infancy) and CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures) is suggested by elevated expression of IFN-I stimulated genes (ISGs). Hitherto, the lack of specific inhibitors of IFN-I signaling has prevented the verification of a causal role for IFN-I in these conditions. Commonly used inhibitors of the JAK/STAT pathway exert broad effects on multiple signaling pathways leading to more general immunosuppression beyond IFN-I signaling. METHODS: Here we show in four patients with SAVI and one patient with CANDLE syndrome that blockade of the IFNAR1 receptor (Anifrolumab) exerts an additive effect over JAK-inhibitor alone. In two patients with SAVI, monotherapy with Anifrolumab is sufficient to retain a suppressed IFN-I signature and clinical improvement. RESULTS: Anifrolumab normalizes IFN-I signature genes and relieves symptoms beyond what is typically achieved by a JAK-inhibitor (Baricitinib) alone in patients with type-I interferonopathies. In two patients Anifrolumab was used successfully as monotherapy. Addition of Anifrolumab enabled steroid tapering and cessation with reduced overall immunosuppression and lower risks of opportunistic infections and improved metabolic states and growth which is highly beneficial in these young patients. CONCLUSION: These results verify a causal role of IFN-I signaling in type-I Interferonopathies SAVI and CANDLE and suggests Anifrolumab as an important new treatment option in autoinflammatory diseases with elevated IFN-I induced gene expression. Genia Kretzschmar, Laura Piñero Páez, and Ziyang Tan are shared-first authors. Sara Alehashemi, AnnaCarin Horne, and Petter Brodin are co-senior author.

Cancer is the leading cause of death from disease in children. Survival depends not only on surgery, cytostatic drugs, and radiation but also on systemic immune responses. Factors influencing these immune responses in children of different ages and tumor types are unknown. Novel immunotherapies can enhance anti-tumor immune responses, but few children have benefited, and markers of effective responses are lacking. Here, we present a systems-level analysis of immune responses in 191 children within a population-based cohort with diverse tumors and reveal that age and tumor type shape immune responses differently. Systemic inflammation and cytotoxic T cell responses correlate with tumor mutation rates and immune cell infiltration. Clonally expanded T cell responses are rarely detected in blood or tumors at diagnosis but are sometimes elicited during treatment. Expanded T cells are similarly regulated in children and adults with more immunogenic cancers. This research aims to facilitate the development of precision immunotherapies for children with cancer.

<h3>Background</h3> Childhood cancer is the second most common cause of death among children in developed countries, although the field of cancer immunotherapy has advanced dramatically, children with solid tumors have not benefitted much from these advances. Pediatric cancers have traditionally been considered non-immunogenic due to their lower mutational burden. However, with more pediatric tumors recently sequenced, it has become apparent that there are considerable variations in the mutational load burden (TMB) among tumors from pediatric patients. So better knowledge of pediatric cancer genomics as well as immunology is needed to advance this field further. <h3>Methods</h3> Whole genome analysis was performed on 140 samples obtained from 135 patients, covering 22 types of childhood solid tumors from Karolinska Hospital. Sarek pipelines were then used to call variants for downstream analysis. Mutational signatures, which are characteristic patterns of somatic mutations reflecting the underlying mutational processes, were extracted using the SigProfiler tool. Immune cell compositions and plasma proteins were measured by mass cytometry (CyTOF) and Olink. Additionally, bulk RNA-seq data from tumor tissues were used to estimate immune cell infiltration and TCR expansion. <h3>Results</h3> Compared with adult patients from TCGA, pediatric cancer exhibits a comparatively lower tumor mutational burden (TMB). However, TMB escalates after relapse or metastasis. Furthermore, the ISAC cohort analysis revealed distinct TMB patterns across different pediatric cancers. It is noteworthy that all samples in the ISAC cohort are microsatellite stable. In-depth analysis identified a total of 38 Single Base Substitution (SBS) signatures and 10 Insertion-Deletion (ID) signatures. ID and SBS signatures with similar etiologies are strongly correlated. SBS40, whose etiology is unknown, is highly associated with high mutation rates, in contrast to the notably low TMB in the APOBEC signature. The TMB-high group shows stronger Th1 responses. For Neuroblastoma (NB), a clear demarcation exists between groups with high and low TMB, which coincides with clinical stratification. Remarkably, the high mutation group has more neutrophils, γδ T cells, fewer NK cells, and an inflammation profile. Reactive oxygen species (SBS18) are mainly found in NB, especially in the high mutation group, and are associated with systemic inflammation. <h3>Conclusions</h3> Based on tumor genomic data and systemic immune-related indicators, these findings illuminate the intricate interplay between TMB, mutational signatures, clinical characteristics, the tumor microenvironment, and systemic immune states in pediatric cancers. This understanding holds significant implications for the future treatment and early diagnosis of pediatric tumors.