Non-redundant functions of group 2 innate lymphoid cells.

Protective immunity relies on the interplay of innate and adaptive immune cells with complementary and redundant functions. Innate lymphoid cells (ILCs) have recently emerged as tissue-resident, innate mirror images of the T cell system, with which they share lineage-specifying transcription factors and effector machinery1. Located at barrier surfaces, ILCs are among the first responders against invading pathogens and thus could potentially determine the outcome of the immune response2. However, so far it has not been possible to dissect the unique contributions of ILCs to protective immunity owing to limitations in specific targeting of ILC subsets. Thus, all of the available data have been generated either in mice lacking the adaptive immune system or with tools that also affect other immune cell subsets. In addition, it has been proposed that ILCs might be dispensable for a proper immune response because other immune cells could compensate for their absence3-7. Here we report the generation of a mouse model based on the neuromedin U receptor 1 (Nmur1) promoter as a driver for simultaneous expression of Cre recombinase and green fluorescent protein, which enables gene targeting in group 2 ILCs (ILC2s) without affecting other innate and adaptive immune cells. Using Cre-mediated gene deletion of Id2 and Gata3 in Nmur1-expressing cells, we generated mice with a selective and specific deficiency in ILC2s. ILC2-deficient mice have decreased eosinophil counts at steady state and are unable to recruit eosinophils to the airways in models of allergic asthma. Further, ILC2-deficient mice do not mount an appropriate immune and epithelial type 2 response, resulting in a profound defect in worm expulsion and a non-protective type 3 immune response. In total, our data establish non-redundant functions for ILC2s in the presence of adaptive immune cells at steady state and during disease and argue for a multilayered organization of the immune system on the basis of a spatiotemporal division of labour.

The miR-221/222 cluster regulates hematopoietic stem cell quiescence and multipotency by suppressing both Fos/AP-1/IEG pathway activation and stress-like differentiation to granulocytes.

Throughout life, hematopoietic stem cells (HSCs), residing in bone marrow (BM), continuously regenerate erythroid/megakaryocytic, myeloid, and lymphoid cell lineages. This steady-state hematopoiesis from HSC and multipotent progenitors (MPPs) in BM can be perturbed by stress. The molecular controls of how stress can impact hematopoietic output remain poorly understood. MicroRNAs (miRNAs) as posttranscriptional regulators of gene expression have been found to control various functions in hematopoiesis. We find that the miR-221/222 cluster, which is expressed in HSC and in MPPs differentiating from them, perturbs steady-state hematopoiesis in ways comparable to stress. We compare pool sizes and single-cell transcriptomes of HSC and MPPs in unperturbed or stress-perturbed, miR-221/222-proficient or miR-221/222-deficient states. MiR-221/222 deficiency in hematopoietic cells was induced in C57BL/6J mice by conditional vav-cre-mediated deletion of the floxed miR-221/222 gene cluster. Social stress as well as miR-221/222 deficiency, alone or in combination, reduced HSC pools 3-fold and increased MPPs 1.5-fold. It also enhanced granulopoisis in the spleen. Furthermore, combined stress and miR-221/222 deficiency increased the erythroid/myeloid/granulocytic precursor pools in BM. Differential expression analyses of single-cell RNAseq transcriptomes of unperturbed and stressed, proficient HSC and MPPs detected more than 80 genes, selectively up-regulated in stressed cells, among them immediate early genes (IEGs). The same differential single-cell transcriptome analyses of unperturbed, miR-221/222-proficient with deficient HSC and MPPs identified Fos, Jun, JunB, Klf6, Nr4a1, Ier2, Zfp36-all IEGs-as well as CD74 and Ly6a as potential miRNA targets. Three of them, Klf6, Nr4a1, and Zfp36, have previously been found to influence myelogranulopoiesis. Together with increased levels of Jun, Fos forms increased amounts of the heterodimeric activator protein-1 (AP-1), which is known to control the expression of the selectively up-regulated expression of the IEGs. The comparisons of single-cell mRNA-deep sequencing analyses of socially stressed with miR-221/222-deficient HSC identify 5 of the 7 Fos/AP-1-controlled IEGs, Ier2, Jun, Junb, Klf6, and Zfp36, as common activators of HSC from quiescence. Combined with stress, miR-221/222 deficiency enhanced the Fos/AP-1/IEG pathway, extended it to MPPs, and increased the number of granulocyte precursors in BM, inducing selective up-regulation of genes encoding heat shock proteins Hspa5 and Hspa8, tubulin-cytoskeleton-organizing proteins Tuba1b, Tubb 4b and 5, and chromatin remodeling proteins H3f3b, H2afx, H2afz, and Hmgb2. Up-regulated in HSC, MPP1, and/or MPP2, they appear as potential regulators of stress-induced, miR-221/222-dependent increased granulocyte differentiation. Finally, stress by serial transplantations of miR-221/222-deficient HSC selectively exhausted their lymphoid differentiation capacities, while retaining their ability to home to BM and to differentiate to granulocytes. Thus, miR-221/222 maintains HSC quiescence and multipotency by suppressing Fos/AP-1/IEG-mediated activation and by suppressing enhanced stress-like differentiation to granulocytes. Since miR-221/222 is also expressed in human HSC, controlled induction of miR-221/222 in HSC should improve BM transplantations.

Barriers and facilitators to cervical cancer screening among under-screened women in Cuenca, Ecuador: the perspectives of women and health professionals.

BACKGROUND: Cervical cancer screening is a cost-effective method responsible for reducing cervical cancer-related mortality by 70% in countries that have achieved high coverage through nationwide screening strategies. However, there are disparities in access to screening. In Ecuador, although cervical cancer is the second most common cancer in women, only 58.4% of women of reproductive age have ever been screened for cervical cancer. METHODOLOGY: A qualitative study was performed to understand the current barriers to screening and to identify strategies that could increase uptake in Azuay province, Ecuador. Seven focus group discussions (FGDs) were conducted with under-screened women and health professionals (HPs). The FGDs were recorded and transcribed. Content analysis was done using the socio-ecological framework to categorize and analyse the data. RESULTS: Overall, 28 women and 27 HPs participated in the study. The two groups perceived different barriers to cervical cancer screening. The HPs considered barriers to be mainly at the policy level (lack of a structured screening plan; lack of health promotion) and the individual level (lack of risk perception; personal beliefs). The women identified barriers mainly at organizational level, such as long waiting times, lack of access to health centres, and inadequate patient-physician communication. Both groups mentioned facilitators at policy level, such as national campaigns promoting cervical cancer screening, and at community and individual level, including health literacy and women's empowerment. CONCLUSIONS: The women considered access to health services the main barrier to screening, while the HPs identified a lack of investment in screening programmes and cultural patterns at the community level as major obstacles. To take an integrated approach to cervical cancer prevention, the perspectives of both groups should be taken into account. Additionally, new strategies and technologies, such as self-administered human papillomavirus (HPV) testing and community participation, should be implemented to increase access to cervical cancer screening.

UNC93B1 variants underlie TLR7-dependent autoimmunity.

UNC93B1 is critical for trafficking and function of nucleic acid-sensing Toll-like receptors (TLRs) TLR3, TLR7, TLR8, and TLR9, which are essential for antiviral immunity. Overactive TLR7 signaling induced by recognition of self-nucleic acids has been implicated in systemic lupus erythematosus (SLE). Here, we report UNC93B1 variants (E92G and R336L) in four patients with early-onset SLE. Patient cells or mouse macrophages carrying the UNC93B1 variants produced high amounts of TNF-α and IL-6 and upon stimulation with TLR7/TLR8 agonist, but not with TLR3 or TLR9 agonists. E92G causes UNC93B1 protein instability and reduced interaction with TLR7, leading to selective TLR7 hyperactivation with constitutive type I IFN signaling. Thus, UNC93B1 regulates TLR subtype-specific mechanisms of ligand recognition. Our findings establish a pivotal role for UNC93B1 in TLR7-dependent autoimmunity and highlight the therapeutic potential of targeting TLR7 in SLE.

Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow.

Bone marrow plasma cells (BMPC) are the correlate of humoral immunity, consistently releasing antibodies into the bloodstream. It remains unclear if BMPC reflect different activation environments or maturation of their precursors. Here we define human BMPC heterogeneity and track the recruitment of antibody-secreting cells (ASC) from SARS-CoV-2 vaccine immune reactions to the bone marrow (BM). Trajectories based on single-cell transcriptomes and repertoires of peripheral and BM ASC reveal sequential colonisation of BMPC compartments. In activated B cells, IL-21 suppresses CD19 expression, indicating that CD19low-BMPC are derived from follicular, while CD19high-BMPC originate from extrafollicular immune reactions. In primary immune reactions, both CD19low- and CD19high-BMPC compartments are populated. In secondary immune reactions, most BMPC are recruited to CD19high-BMPC compartments, reflecting their origin from extrafollicular reactivations of memory B cells. A pattern also observable in vaccinated-convalescent individuals and upon diphtheria/tetanus/pertussis recall-vaccination. Thus, BMPC diversity reflects the evolution of a given humoral immune response.

Distinct tissue niches direct lung immunopathology via CCL18 and CCL21 in severe COVID-19.

Prolonged lung pathology has been associated with COVID-19, yet the cellular and molecular mechanisms behind this chronic inflammatory disease are poorly understood. In this study, we combine advanced imaging and spatial transcriptomics to shed light on the local immune response in severe COVID-19. We show that activated adventitial niches are crucial microenvironments contributing to the orchestration of prolonged lung immunopathology. Up-regulation of the chemokines CCL21 and CCL18 associates to endothelial-to-mesenchymal transition and tissue fibrosis within these niches. CCL21 over-expression additionally links to the local accumulation of T cells expressing the cognate receptor CCR7. These T cells are imprinted with an exhausted phenotype and form lymphoid aggregates that can organize in ectopic lymphoid structures. Our work proposes immune-stromal interaction mechanisms promoting a self-sustained and non-resolving local immune response that extends beyond active viral infection and perpetuates tissue remodeling.

Cross-regulation of antibody responses against the SARS-CoV-2 Spike protein and commensal microbiota via molecular mimicry.

The commensal microflora provides a repertoire of antigens that illicit mucosal antibodies. In some cases, these antibodies can cross-react with host proteins, inducing autoimmunity, or with other microbial antigens. We demonstrate that the oral microbiota can induce salivary anti-SARS-CoV-2 Spike IgG antibodies via molecular mimicry. Anti-Spike IgG antibodies in the saliva correlated with enhanced abundance of Streptococcus salivarius 1 month after anti-SARS-CoV-2 vaccination. Several human commensal bacteria, including S. salivarius, were recognized by SARS-CoV-2-neutralizing monoclonal antibodies and induced cross-reactive anti-Spike antibodies in mice, facilitating SARS-CoV-2 clearance. A specific S. salivarius protein, RSSL-01370, contains regions with homology to the Spike receptor-binding domain, and immunization of mice with RSSL-01370 elicited anti-Spike IgG antibodies in the serum. Additionally, oral S. salivarius supplementation enhanced salivary anti-Spike antibodies in vaccinated individuals. Altogether, these data show that distinct species of the human microbiota can express molecular mimics of SARS-CoV-2 Spike protein, potentially enhancing protective immunity.

B Cell Numbers Predict Humoral and Cellular Response Upon SARS-CoV-2 Vaccination Among Patients Treated With Rituximab.

OBJECTIVE: Patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk of poor COVID-19 outcomes and show substantially impaired humoral immune response to anti-SARS-CoV-2 vaccine. However, the complex relationship between antigen-specific B cells and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown. METHODS: Antibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 patients with rheumatoid arthritis (RA) or antineutrophil cytoplasmic antibody-associated vasculitis receiving RTX, 12 patients with RA receiving other therapies, and 30 healthy controls after SARS-CoV-2 vaccination with either messenger RNA or vector-based vaccines. RESULTS: A minimum of 10 B cells per microliter (0.4% of lymphocytes) in the peripheral circulation appeared to be required for RTX-treated patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX-treated patients who lacked IgG seroconversion showed reduced receptor-binding domain-positive B cells (P = 0.0005), a lower frequency of Tfh-like cells (P = 0.0481), as well as fewer activated CD4 (P = 0.0036) and CD8 T cells (P = 0.0308) compared to RTX-treated patients who achieved IgG seroconversion. Functionally relevant B cell depletion resulted in impaired interferon-γ secretion by spike-specific CD4 T cells (P = 0.0112, r = 0.5342). In contrast, antigen-specific CD8 T cells were reduced in both RA patients and RTX-treated patients, independently of IgG formation. CONCLUSION: In RTX-treated patients, a minimum of 10 B cells per microliter in the peripheral circulation is a candidate biomarker for a high likelihood of an appropriate cellular and humoral response after SARS-CoV-2 vaccination. Mechanistically, the data emphasize the crucial role of costimulatory B cell functions for the proper induction of CD4 responses propagating vaccine-specific B cell and plasma cell differentiation.

Cell Type-Specific Role of RNA Nuclease SMG6 in Neurogenesis.

SMG6 is an endonuclease, which cleaves mRNAs during nonsense-mediated mRNA decay (NMD), thereby regulating gene expression and controling mRNA quality. SMG6 has been shown as a differentiation license factor of totipotent embryonic stem cells. To investigate whether it controls the differentiation of lineage-specific pluripotent progenitor cells, we inactivated Smg6 in murine embryonic neural stem cells. Nestin-Cre-mediated deletion of Smg6 in mouse neuroprogenitor cells (NPCs) caused perinatal lethality. Mutant mice brains showed normal structure at E14.5 but great reduction of the cortical NPCs and late-born cortical neurons during later stages of neurogenesis (i.e., E18.5). Smg6 inactivation led to dramatic cell death in ganglionic eminence (GE) and a reduction of interneurons at E14.5. Interestingly, neurosphere assays showed self-renewal defects specifically in interneuron progenitors but not in cortical NPCs. RT-qPCR analysis revealed that the interneuron differentiation regulators Dlx1 and Dlx2 were reduced after Smg6 deletion. Intriguingly, when Smg6 was deleted specifically in cortical and hippocampal progenitors, the mutant mice were viable and showed normal size and architecture of the cortex at E18.5. Thus, SMG6 regulates cell fate in a cell type-specific manner and is more important for neuroprogenitors originating from the GE than for progenitors from the cortex.

Impaired humoral immunity to SARS-CoV-2 BNT162b2 vaccine in kidney transplant recipients and dialysis patients.

Patients with kidney failure are at increased risk for SARS-CoV-2 infection making effective vaccinations a critical need. It is not known how well mRNA vaccines induce B and plasma cell responses in dialysis patients (DP) or kidney transplant recipients (KTR) compared to healthy controls (HC). We studied humoral and B cell responses of 35 HC, 44 DP and 40 KTR. Markedly impaired anti-BNT162b2 responses were identified among KTR and DP compared to HC. In DP, the response was delayed (3-4 weeks after boost) and reduced with anti-S1 IgG and IgA positivity in 70.5% and 68.2%, respectively. In contrast, KTR did not develop IgG responses except one patient who had a prior unrecognized infection and developed anti-S1 IgG. The majority of antigen-specific B cells (RBD+) were identified in the plasmablast or post-switch memory B cell compartments in HC, whereas RBD+ B cells were enriched among pre-switch and naïve B cells from DP and KTR. The frequency and absolute number of antigen-specific circulating plasmablasts in the cohort correlated with the Ig response, a characteristic not reported for other vaccinations. In conclusion, these data indicated that immunosuppression resulted in impaired protective immunity after mRNA vaccination, including Ig induction with corresponding generation of plasmablasts and memory B cells. Thus, there is an urgent need to improve vaccination protocols in patients after kidney transplantation or on chronic dialysis.

SARS-CoV-2 in severe COVID-19 induces a TGF-ß-dominated chronic immune response that does not target itself.

The pathogenesis of severe COVID-19 reflects an inefficient immune reaction to SARS-CoV-2. Here we analyze, at the single cell level, plasmablasts egressed into the blood to study the dynamics of adaptive immune response in COVID-19 patients requiring intensive care. Before seroconversion in response to SARS-CoV-2 spike protein, peripheral plasmablasts display a type 1 interferon-induced gene expression signature; however, following seroconversion, plasmablasts lose this signature, express instead gene signatures induced by IL-21 and TGF-ß, and produce mostly IgG1 and IgA1. In the sustained immune reaction from COVID-19 patients, plasmablasts shift to the expression of IgA2, thereby reflecting an instruction by TGF-ß. Despite their continued presence in the blood, plasmablasts are not found in the lungs of deceased COVID-19 patients, nor does patient IgA2 binds to the dominant antigens of SARS-CoV-2. Our results thus suggest that, in severe COVID-19, SARS-CoV-2 triggers a chronic immune reaction that is instructed by TGF-ß, and is distracted from itself.

Consecuencias físicas y psicológicas de la violencia obstétrica en países de Latinoamérica / Physical and psychological consequences of obstetric violence in Latin American countries

El término violencia obstétrica tiene sus orígenes en Latinoamérica, se considera una expresión de violencia de género y de violencia institucional contra la mujer. Puede ser ejercida de dos maneras, física y psicológica, por lo que se pretende definir la violencia obstétrica, su origen, divisiones, relación con los derechos sexuales y reproductivos de la mujer, así como identificar sus consecuencias físicas y psicológicas. Se realizó una búsqueda bibliográfica en Medigraphic, SciELO y Google Académico, fueron incluidas únicamente las publicaciones que se encontraron a texto completo, en español, inglés y portugués durante los años 2014 al 2022. La violencia obstétrica provoca que los derechos sexuales y reproductivos de las mujeres sean quebrantados, lo que hace imprescindible que todos los involucrados en la atención en salud conozcan las repercusiones físicas y psicológicas relacionadas que contribuyen a la morbimortalidad de la madre y el recién nacido, tales como: desgarros vaginales, problemas en la lactancia materna, síndrome de estrés postraumático y depresión posparto

The term obstetric violence has its origins in Latin America, it is considered an expression of gender violence and institutional violence against women. It can be exercised in two ways, physical and psychological, therefore, the aim is to define obstetric violence, its origin, divisions, and relation with women's sexual and reproductive rights, as well as to identify its physical and psychological consequences. A bibliographic search was conducted in Medigraphic, SciELO, and Google Scholar, including only publications that were found in full text, in Spanish, English, and Portuguese during the years 2014 to 2022. Obstetric violence causes the violation of women's sexual and reproductive rights, which makes it essential for all those involved in health care to be aware of the related physical and psychological repercussions that contribute to maternal and newborn morbidity and mortality, such as vaginal tears, breastfeeding problems, post-traumatic stress syndrome, and postpartum depression

Understanding dengue virus capsid protein disordered N-Terminus and pep14-23-based inhibition.

Dengue virus (DENV) infection affects millions of people and is becoming a major global disease for which there is no specific available treatment. pep14-23 is a recently designed peptide, based on a conserved segment of DENV capsid (C) protein. It inhibits the interaction of DENV C with host intracellular lipid droplets (LDs), which is crucial for viral replication. Combining bioinformatics and biophysics, here, we analyzed pep14-23 structure and ability to bind different phospholipids, relating that information with the full-length DENV C. We show that pep14-23 acquires α-helical conformation upon binding to negatively charged phospholipid membranes, displaying an asymmetric charge distribution structural arrangement. Structure prediction for the N-terminal segment reveals four viable homodimer orientations that alternatively shield or expose the DENV C hydrophobic pocket. Taken together, these findings suggest a new biological role for the disordered N-terminal region, which may function as an autoinhibitory domain mediating DENV C interaction with its biological targets. The results fit with our current understanding of DENV C and pep14-23 structure and function, paving the way for similar approaches to understanding disordered proteins and improved peptidomimetics drug development strategies against DENV and similar Flavivirus infections.

Lipidomic characterization of streptozotocin-induced heart mitochondrial dysfunction.

Myocardial mitochondria dysfunction seems to represent an important pathogenic factor underlying cardiomyopathy, a common complication of type 1 diabetes mellitus (T1DM). Despite significant progress in the understanding of the molecular mechanisms of mitochondrial function in the heart, the interplay between phospholipids and membrane proteins of this organelle is still poorly comprehended. Using a well-characterized animal model of T1DM obtained by the administration of streptozotocin, phospholipid profiling of isolated mitochondria was performed using MS-based approaches, which was analyzed together with oxidative phosphorylation (OXPHOS) complexes activities and their susceptibility to oxidation, and the expression of cytochrome c, the uncoupling protein UCP-3 and the mitochondrial transcription factor Tfam. Although in higher amounts, mitochondria from T1DM heart presented lower OXPHOS activity and lower transcription ability. This profile was related to phospholipid (PL) remodeling characterized by higher phosphatidylcholine levels, lower phosphatidylglycerol, phosphatidylinositol and sphingomyelin content, higher amounts of long fatty acyl side chains and increased lipid peroxidation, particularly of cardiolipin (CL). CL peroxidation was paralleled by lower cytochrome c content. Though in higher levels, UCP-3 does not seem to protect heart mitochondrial PL and membrane proteins from the oxidative damage induced by four weeks of hyperglycemia. Taken together, our data suggest that PL remodeling of heart mitochondria is an early event in T1DM pathogenesis and is related with OXPHOS dysfunction.