Infection with hypervirulent Mycobacterium tuberculosis triggers emergency myelopoiesis but not trained immunity.

Introduction: During infection, bone marrow (BM) hematopoiesis is reprogrammed toward myeloid cell production, a mechanism named emergency myelopoiesis. In addition to replenishing myeloid cells, emergency myelopoiesis has been linked to trained immunity, a process that allows enhanced innate immune responses to secondary challenges. Although hematopoietic alterations during tuberculosis (TB) have been described and Mycobacterium tuberculosis may colonize the BM, studies using the mouse model of infection and the laboratory reference strain M. tuberculosis H37Rv have demonstrated limited emergency myelopoiesis and trained immunity. Methods: To further address this issue, we aerosol- infected C57BL/6 mice with high doses of the hypervirulent M. tuberculosis isolate HN878 and monitored alterations to the BM. This experimental model better resembles the human blood immune signature of TB. Results and discussion: We found increased frequencies of lineage-Sca-1+cKit+ (LSK) cells and the granulocyte/macrophage progenitor (GMP) population. At the mature cell level, we observed an increase of monocytes and neutrophils in the blood and lung, likely reflecting the increased BM myeloid output. Monocytes or monocyte-derived macrophages recovered from the BM of M. tuberculosis HN878-infected mice did not show signs of trained immunity, suggesting an uncoupling of emergency myelopoiesis and trained immunity in the BM. Surprisingly, M. tuberculosis HN878-induced emergency myelopoiesis was not fully dependent on IFNγ, as mice lacking this cytokine and infected under the same conditions as wild-type mice still presented BM alterations. These data expand our understanding of the immune response to M. tuberculosis and raise awareness of pathogen strain-imposed differences to host responses.

Protocol for infecting and monitoring susceptible k18-hACE2 mice with SARS-CoV-2.

Intranasal infection of k18-hACE2 mice with SARS-CoV-2 recapitulates the clinical characteristics present in severe COVID-19. Here, we present a protocol for intranasal administration of SARS-CoV-2 to k18-hACE2 mice and their subsequent daily monitoring. We describe steps for intranasal inoculation of SARS-CoV-2 and the collection of clinical scores on weight, body condition, hydration, appearance, neurological symptoms, behavior, and respiratory movements. This protocol contributes to the establishment of a model of severe SARS-CoV-2 infection that minimizes animal suffering. For complete details on the use and execution of this protocol, please refer to Gonçalves et al. (2023).1.

SARS-CoV-2 variants induce distinct disease and impact in the bone marrow and thymus of mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved to variants associated with milder disease. We employed the k18-hACE2 mouse model to study how differences in the course of infection by SARS-CoV-2 variants alpha, delta, and omicron relate to tissue pathology and the immune response triggered. We documented a variant-specific pattern of infection severity, inducing discrete lung and blood immune responses and differentially impacting primary lymphoid organs. Infections with variants alpha and delta promoted bone marrow (BM) emergency myelopoiesis, with blood and lung neutrophilia. The defects in the BM hematopoietic compartment extended to the thymus, with the infection by the alpha variant provoking a marked thymic atrophy. Importantly, the changes in the immune responses correlated with the severity of infection. Our study provides a comprehensive platform to investigate the modulation of disease by SARS-CoV-2 variants and underscores the impact of this infection on the function of primary lymphoid organs.

Advances on the Role and Applications of Interleukin-1 in Tuberculosis.

Interleukin-1 (IL-1) is a key player in the immune response to pathogens due to its role in promoting inflammation and recruiting immune cells to the site of infection. In tuberculosis (TB), tight regulation of IL-1 responses is critical to ensure host resistance to infection while preventing immune pathology. In the mouse model of Mycobacterium tuberculosis infection, both IL-1 absence and overproduction result in exacerbated disease and mortality. In humans, several polymorphisms in the IL1B gene have been associated with increased susceptibility to TB. Importantly, M. tuberculosis itself has evolved several strategies to manipulate and regulate host IL-1 responses for its own benefit. Given all this, IL-1 appears as a promising target for host-directed therapies in TB. However, for that to succeed, more detailed knowledge on the biology and mechanisms of action of IL-1 in vivo, together with a deep understanding of how host-M. tuberculosis interactions modulate IL-1, is required. Here, we discuss the most recent advances in the biology and therapeutic potential of IL-1 in TB as well as the outstanding questions that remain to be answered.

Direct tissue-sensing reprograms TLR4+ Tfh-like cells inflammatory profile in the joints of rheumatoid arthritis patients.

CD4+ T cells mediate rheumatoid arthritis (RA) pathogenesis through both antibody-dependent and independent mechanisms. It remains unclear how synovial microenvironment impinges on CD4+ T cells pathogenic functions. Here, we identified a TLR4+ follicular helper T (Tfh) cell-like population present in the blood and expanded in synovial fluid. TLR4+ T cells possess a two-pronged pathogenic activity whereby direct TLR4+ engagement by endogenous ligands in the arthritic joint reprograms them from an IL-21 response, known to sponsor antibody production towards an IL-17 inflammatory program recognized to fuel tissue damage. Ex vivo, synovial fluid TLR4+ T cells produced IL-17, but not IL-21. Blocking TLR4 signaling with a specific inhibitor impaired IL-17 production in response to synovial fluid recognition. Mechanistically, we unveiled that T-cell HLA-DR regulates their TLR4 expression. TLR4+ T cells appear to uniquely reconcile an ability to promote systemic antibody production with a local synovial driven tissue damage program.

Functional Redundancy in bird community decreases with riparian forest width reduction.

Riparian ecosystems are suffering anthropogenic threats that reduce biodiversity and undermine ecosystem services. However, there is a great deal of uncertainty about the way species composition of assemblages is related to ecosystem function, especially in a landscape fragmentation context.Here, we assess the impact of habitat loss and disturbance on Functional Diversity (FD) components Functional Redundancy (FRed), Functional Evenness (FEve), and Functional Richness (FRic) of riparian forest bird assemblages to evaluate (a) how FD components respond to riparian forest width reduction and vegetation disturbance; (b) the existence of thresholds within these relationships; (c) which of the main birds diet guild (frugivores, insectivores, and omnivores) respond to such thresholds. We predict that FD components will be affected negatively and nonlinearly by riparian changes. However, guilds could have different responses due to differences of species sensitivity to fragmentation and disturbance. We expect to find thresholds in FD responses, because fragmentation and disturbance drive loss of specific FD components.Our results show that FRed and FEve were linearly affected by width and disturbance of riparian habitats, respectively. FRed was significantly lower in riparian forests assemblages below 400 m wide, and FEve was significantly higher above 60% disturbance. These responses of FD were also followed to the decline in insectivores and frugivores richness in riparian forests most affected by these changes.Consequently, our study suggests communities do not tolerate reduction in riparian forest width or disturbance intensification without negative impact on FD, and this becomes more critical for riparian area <400-m wide or with more than 60% disturbance. This minimum riparian width required to maintain FRed is greater than the minimum width required for riparian forests by Brazilian law. Thus, it is important to consider mechanisms to expand riparian habitats and reduce the disturbance intensity in riparian forests so that riparian bird community FD may be effectively conserved.

Celiac disease in children from Madeira island and its prevalence in first degree relatives.

CONTEXT: It is well recognized that celiac disease is an immune-mediated systemic disorder highly prevalent among relatives of celiac patients. OBJECTIVES: The aim of this study is to determine the prevalence of celiac disease in a group of first degree relatives of celiac children, and to access the frequency of human leukocyte antigen HLA-DQ2 and DQ8 in celiac disease patients and their affected relatives. METHODS: A survey was conducted of 39 children with celiac disease with follow-up in the Pediatric outpatient's clinic of Dr. Nélio Mendonça Hospital, in Madeira Island, Portugal. Were invited 110 first degree relatives to undergo serological screen for celiac disease with IgA antibody to human recombinant tissue transglutaminase (IgA-TGG) quantification. In all seropositive relatives, small intestinal biopsy and HLA typing was recommended. RESULTS: HLA- typing was performed in 38 celiac patients, 28/74% DQ2 positive, 1/2% DQ8 positive and 9/24% incomplete DQ2. Positive IgA-TGG was found in five out of the 95 relatives, and CD was diagnosed in three of them. Three relatives had the presence of HLA-DQ2, two were DQ2 incomplete (DQB1*02). CONCLUSIONS: The prevalence of celiac disease among first degree celiac patients´ relatives was 3.1%, 4.5 times higher than the general Portuguese population (0,7%) witch reinforces the need of extensive diagnostic screening in this specific group. HLA-DQ2 typing may be a tool in the diagnostic approach.

Celiac disease nn children from madeira island and its prevalence in first degree reaatives / Doença celíaca em idade pediátrica na Ilha da Madeira e sua prevalência em familiares de primeiro grau

Context It is well recognized that celiac disease is an immune-mediated systemic disorder highly prevalent among relatives of celiac patients. Objectives The aim of this study is to determine the prevalence of celiac disease in a group of first degree relatives of celiac children, and to access the frequency of human leukocyte antigen HLA-DQ2 and DQ8 in celiac disease patients and their affected relatives. Methods A survey was conducted of 39 children with celiac disease with follow-up in the Pediatric outpatient’s clinic of Dr. Nélio Mendonça Hospital, in Madeira Island, Portugal. Were invited 110 first degree relatives to undergo serological screen for celiac disease with IgA antibody to human recombinant tissue transglutaminase (IgA-TGG) quantification. In all seropositive relatives, small intestinal biopsy and HLA typing was recommended. Results HLA- typing was performed in 38 celiac patients, 28/74% DQ2 positive, 1/2% DQ8 positive and 9/24% incomplete DQ2. Positive IgA-TGG was found in five out of the 95 relatives, and CD was diagnosed in three of them. Three relatives had the presence of HLA-DQ2, two were DQ2 incomplete (DQB1*02). Conclusions The prevalence of celiac disease among first degree celiac patients´ relatives was 3.1%, 4.5 times higher than the general Portuguese population (0,7%) witch reinforces the need of extensive diagnostic screening in this specific group. HLA-DQ2 typing may be a tool in the diagnostic approach. .

Contexto A doença celíaca é uma doença sistémica autoimune muito prevalente nos familiares de primeiro grau de doentes celíacos. Objetivos O objetivo deste estudo é determinar a prevalência de doença celíaca, num grupo de familiares de primeiro grau de crianças com o diagnóstico de doença celíaca e, determinar a frequência de antígeno leucocitário humano (HLA)-DQ2 e DQ8 nos doentes celíacos e seus familiares afetados. Métodos Foi feita a pesquisa dos processos clínicos de 39 crianças com o diagnóstico de doença celíaca seguidas na consulta de Gastroenterologia Pediátrica do Hospital Dr. Nélio Mendonça na Ilha da Madeira, Portugal. Foram convidados 110 familiares de primeiro grau para a realização do rastreio serológico de doença celíaca através da quantificação do anticorpo IgA anti-transglutaminase tecidular humano (IgA-TGG). Aos familiares com resultado positivo no rastreio, foi recomendada a realização de biópsia intestinal e tipificação HLA. Resultados A tipificação HLA foi realizada em 38 crianças. Verificou-se a presença do heterodímero DQ2 em 28/74%, DQ8 em 1/2% e DQ2 incompleto em 9/24% das crianças. O rastreio de DC com IgA-TGG foi positivo em cinco dos 95 familiares analisados, tendo sido diagnosticada doença celíaca em três destes. Verificou-se a presença do heterodímero HLA-DQ2 em três familiares e HLA-DQ2 incompleto (DQB1*02) em dois familiares. Conclusões A prevalência de doença celíaca em familiares de primeiro grau de doentes celíacos foi 3.1%, 4.5 vezes mais elevada do que a da população Portuguesa geral (0,7%), o que reforça a importância de alargar o rastreio a este grupo específico. A tipificação ...

Recurrent gastric lactobezoar in an infant.

Lactobezoars are a type of bezoar composed of undigested milk and mucus. The aetiology is likely multifactorial, being classically described in association with pre-term, low-birth weight infants fed with hyperconcentrated formula. The authors present a case of lactobezoar recurrence in a pre-term infant with oesophageal atresia. To our knowledge, this is the first report of recurrence of lactobezoar.

[Pediatric obesity: the reality of one consultation]. / Obesidade Pediátrica: A Realidade de Uma Consulta.

BACKGROUND: The prevalence of paediatric obesity is constantly rising. The association to cardiovascular risk, diabetes and psychosocial disturbances is a concern. Precocious identification and intervention is essential to reduce the negative impact on adult life. MATERIAL AND METHODS: Evaluation of the expression of comorbidities and the multidisciplinary intervention on nutritional status and body composition in obese children and adolescents, at six months follow-up on the Paediatric Obesity consultation. Retrospective analysis from the clinical files of under 17 years-old patients, followed from January 2005 to December 2008. RESULTS: We followed 67 children and adolescents, mostly female. Overweight emerged at 4.6 years and the first evaluation in our consult occurred at 9.1 years-old, on average. Primary health care colleagues referred most patients (47.8%). The commonest predictor of obesity was parental obesity (60%). Planned physical activity was poorer in the lowest school years. Severe obesity was the most prevalent type of obesity (70%). Both genders showed a different fat distribution (female: non-central; male: central). Frequent findings on physical examination were: striae, adipomastia, acanthosis nigricans and orthopedic changes. In the first evaluation, although 6% of patients have shown high blood pressure, 34.4% insulin resistance and 56.7% dyslipidemia, only 7.7% met criteria for metabolic syndrome. Other associated comorbidities were psychosocial problems (23.9%), asthma (16.4%), orthopedic (10.5%) and gastrointestinal (3%) diseases. BMI percentile reduction occurred in 51% of cases, after 6 months of intervention. The increase on physical activity was reported by 56.7% of patients. Bioelectrical impedance showed an average fat mass reduction of 0.8%. At the end of the studied period, dropout rate from this consultation was admirably high (28.4%). CONCLUSION: Multidisciplinary involvement of all health professionals, schools and family is essential for paediatric obesity intervention. Anthropometric evaluation should always include the waist circumference and BMI estimate. Bioelectrical impedance can be used to evaluate the individual changes in body composition. Changing lifestyle habits is still the most effective treatment as success will mainly depend on the patient and family motivation.