Bronchus-associated Lymphoid Tissue Research Articles

Regulation of pulmonary plasma cell responses during secondary infection with influenza virus.

During secondary infection with influenza virus, plasma cells (PCs) develop within the lung, providing a local source of antibodies. However, the site and mechanisms that regulate this process are poorly defined. Here, we show that while circulating memory B cells entered the lung during rechallenge and were activated within inducible bronchus-associated lymphoid tissues (iBALTs), resident memory B (BRM) cells responded earlier, and their activation occurred in a different niche: directly near infected alveoli. This process required NK cells but was largely independent of CD4 and CD8 T cells. Innate stimuli induced by virus-like particles containing ssRNA triggered BRM cell differentiation in the absence of cognate antigen, suggesting a low threshold of activation. In contrast, expansion of PCs in iBALTs took longer to develop and was critically dependent on CD4 T cells. Our work demonstrates that spatially distinct mechanisms evolved to support pulmonary secondary PC responses, and it reveals a specialized function for BRM cells as guardians of the alveoli.

Treatment outcome, toxicity, and quality of life of patients with bronchus-associated lymphoid tissue lymphoma

The disease failure patterns and optimal treatment of bronchus-associated lymphoid tissue (BALT) lymphoma are unknown. This retrospective study involved 71 patients with primary BALT lymphoma who had received radiotherapy (RT), surgery, immunochemotherapy (IC), or observation. The median follow-up time was 66 months. The 5-year overall survival and lymphoma-specific survival were 91.2% and 96.1%, respectively, and were not significantly different among treatments. The 5-year cumulative incidence of overall failure for RT, surgery, IC, and observation was 0%, 9.7% (p = .160), 30.8% (p = .017), and 31.3% (p = .039). There was no grade ≥3 toxicity in RT group according to the CTCAE 5.0 reporting system. Quality of life (QoL) was at similarly good levels among the treatment groups. BALT lymphoma had a favorable prognosis but persistent risk of relapse after IC or observation. Given the very low disease failure risk and good QoL, RT remains an effective initial treatment for BALT lymphoma. Key Points BALT lymphoma has a favorable prognosis but a persistent progression and relapse risk. Radiotherapy is associated with lower failure of disease progression and relapse, low toxicity and good quality of life.

Pathological analysis and etiological assessment of pulmonary lesions and its association with pleurisy in slaughtered pigs

The intensification of pig farming has posed significant challenges in managing and preventing sanitary problems, particularly diseases of the respiratory complex. Monitoring at slaughter is an important control tool and cannot be overstated. Hence, this study aimed at characterizing both macroscopical and microscopical lesions and identifying the Actinobacillus pleuropneumoniae (APP), Mycoplasma hyopneumoniae (Mhyo), and Pasteurella multocida (PM) associated with pleurisy in swine. For this, a selected slaughterhouse in São Paulo State underwent a thorough examination of carcasses on the slaughter line, followed by lung sampling. The carcasses and lungs underwent macroscopical examination and were classified according to the score of pleurisy and lung samples were allocated into five groups, being: G0: score 0 – no lesions; G1: score 1; G2: score 2; G3: score 3; and G4: score 4. In total, 217 lung fragments were collected, for the histopathological evaluation and detection of the following respiratory pathogens: APP, Mhyo, and PM by qPCR. The results demonstrated that Mhyo and APP were the most prevalent etiological agents (single and co-identification) in lung samples, in different scores of pleurisies, while bronchopneumonia and bronchus-associated lymphoid tissue (BALT) hyperplasia lesions were the most frequent histopathological findings. Positive correlations were found between the quantification of APP DNA with 1) the score of pleurisy (R=0.254); 2) with the score of lung consolidation in all lung lobes (R=0.181 to R=0.329); and 3) with the score of lung consolidation in the entire lung (R=0.389). The study brings relevant information regarding the main bacterial pathogens associated with pleurisy in pigs and helps with understanding the relationship between the abovementioned pathogens and their impact on the respiratory health of pigs.

Granulomatous pneumonia due to metastrongylus species associated with <i>Mycoplasma hyopneumoniae</i> and <i>Pasteurella multocida</i> in slaughtered pigs

Pneumonia has been identified as one of the limiting factors to pig production. Some of the pneumonia-inducing agents include Mycoplasma hyopneumoniae (MHYO), the primary cause of enzootic pneumonia and Metastrongylus species. which are widely distributed lungworms commonly found in indigenous free-range pigs. This paper describes the pathological findings of 6 cases out of 204 lungs randomly collected from slaughtered pigs in Southwest Nigeria. Samples of the lungs were collected from the cases for bacterial culture, histopathology and detection of MHYO antigens using immunohistochemisty. Gross lesions were severe acute lobular bronchopneumonia (104/204, 50.98%) and greyish discrete nodules in the lungs. Microscopically, there were varying degrees of lymphoid hyperplasia of bronchial-associated lymphoid tissue (BALT) (82.2%), suppurative bronchiolitis with widespread bronchiolar epithelial cells necrosis (57.4%) and granulomatous bronchopneumonia with presence of Metastrongylus spp. and bronchiolar intraluminal cellular exudate consisting predominantly of eosinophils (2.9%). Pasteurella multocida was the most isolated bacterial pathogen (49.0%) either as a single pathogen or in combination with other pathogens from the infected lung samples. Immunohistochemical labelling showed strong MHYO antigens on the surface of bronchial epithelial cells in infected lungs (86/204). This is the first report of granulomatous bronchopneumonia due to Metastrongylus spp. associated with a co-infection of MHYO and Pasteurella multocida in Nigerian indigenous pigs. It is suggested that metastrongylosis may be more common than reported in this study. The detection of respiratory pathogens such as Mycoplasma. hyopneumoniae, Metasrongylusspp. and Pasteurella multocida suggest that they are potential contributors to bronchopneumonia observed in this study.

Effect of Usnea longissima ethyl acetate extract on acute oxidative and inflammatory lung damage from Staphylococcus aureus infection in rats.

The role of oxidants and proinflammatory cytokines in the pathogenesis of pneumonia caused by Staphylococcus aureus (S. aureus) has been demonstrated. The present study aims to investigate the protective effect of ethyl acetate extract (EtOAc) obtained from Usnea longissima (UL) against acute oxidative and inflammatory lung damage due to S. aureus infection in rats. Albino Wistar-type male rats were divided into three groups: Healthy (HG), S. aureus inoculated (SaG), and S. aureus inoculated + ULEtOAc administered (SUL). SaG (n = 6) and SUL (n = 6) group rats' left nostrils (excluding HG) were inoculated with 0.1 ml bacterial mixture. After 24 hours, ULEtOAc (50 mg/kg) was administered orally to the SUL group, and the same volume of normal saline was administered orally to the HG (n = 6) and SaG groups. This procedure was performed once a day for seven days. Levels of oxidant and antioxidant parameters such as malondialdehyde (MDA) and total glutathione (tGSH), as well as pro-inflammatory cytokine levels such as nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-one beta (IL-1β), were measured in removed lung tissues. Tissues were also examined histopathologically. Biochemical results showed that ULEtOAc significantly suppressed the increase of MDA, NF-κB, TNF-α, and IL-1β levels and the decrease of tGSH caused by S. aureus in lung tissue. S. aureus inoculation caused severe mononuclear cell infiltration in interstitial areas, severe lymphoid hyperplasia in bronchial-associated lymphoid tissue and severe alveolar edema, histopathologically. Treatment with ULEtOAc had an attenuating effect on these histopathological findings. Experimental results from this study suggest that ULEtOAc may be beneficial in treating S. aureus-induced oxidative and inflammatory lung damage.

Real-World Data of Outcome of Patients with Newly Diagnosed Bronchial-Associated Lymphoid Tissue Lymphoma: A Multi-Center Retrospective Analysis with Long-Term Survivors

Introduction Extranodal marginal-zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) is an indolent type of non-Hodgkin's lymphoma. Although the lung is the second most common site, it accounts for less than 1% of all lymphomas. Extranodal MZL of MALT type of the lungs originates from bronchial-associated lymphoid tissue (BALT) and is clinically referred to as “BALT lymphoma” or “BALToma”. The indolent nature of BALTomas results in none or mild symptoms and their slow growth pattern allows for various treatment approaches. Depending on the case, active surveillance may be considered, while others may benefit from surgery, radiotherapy or chemotherapy. Despite some existing reviews on this lymphoma, comprehensive characterization of optimal management and prognostic factors remains inadequately defined. Limited case reports and small-scale retrospective data analyses have been conducted, but the number of patients included in these studies was highly restricted. In this study, we conducted a retrospective analysis of clinical data from 67 BALToma patients in South Korea. Methods 67 patients were included in our analysis, all of whom were diagnosed with BALToma between September 1996 and January 2023 at three institutions in South Korea. The criteria for case inclusion was histologically confirmed diagnosis of extranodal MZL of pulmonary origin in accordance with WHO classifications, and availability of clinical data. Extranodal MZL was diagnosed based on WHO classifications, along with the findings from immunohistochemical staining for CD20 and CD3. If needed, CD5, CD10, CD23, cyclin D1, BCL6, and Ki-67 was also stained. Gene rearrangement studies targeting the IgH gene were conducted using PCR analysis. Patients were treated according to the stage and location of the disease. The patients were analyzed into two groups; observation or localized treatment and systemic chemotherapy. Localized treatment included surgery or radiotherapy. Systemic chemotherapy regimens used were mainly (R)-CVP and (R)-CHOP. Baseline characteristics was analyzed with Fisher's exact test. Overall survival (OS) and Progression Free Survival (PFS) were estimated using the Kaplan-Meier method. PFS was calculated from the date of diagnosis to the date on which progression was noted, the date of the last follow-up, or the date of death. OS was measured from the date of diagnosis to the date of death or the last follow-up visit. Survival rates were compared for statistical differences via Generalized Wilcoxon analyses. Prognostic factor analysis and hazard ratio was calculated using univariate and multivariate Cox Regression method. All statistical tests were two-sided, and p < 0.05 was considered statistically significant. All data was analyzed using SPSS Statistics for Windows, Version 27.0. Results The clinical characteristics of patients according to treatment modality was analyzed (Table 1). Gender, age, performance status was not significantly different between each group. Notably, involvement of single or multiple lobe (p=0.045), involvement of bilateral lung (p<0.001), nodal involvement (p=0.033), and involvement of extrapulmonary organ (p=0.010) was significantly different between each group. The PFS and OS according to treatment method are provided in Figure 1 and 2. 10-year PFS for observation or localized treatment was 78.7% whereas chemotherapy was 56.9% (p=0.044). 10-year OS for observation or localized treatment was 100%, whereas chemotherapy was 71.7% (p=0.016). The prognostic factors for progression of disease were significant only for the involvement of extrapulmonary organ in both univariate and multivariate (hazard ratio 3.615, p=0.023) analysis (Table 2). Prognostic factor analysis for overall survival did not yield any significant result. Conclusion This study concludes that the most important prognostic factor for the progression of disease is the involvement of extrapulmonary organ. This study implies that the feasibility of simply monitoring patients whose disease is confined exclusively to the lung is a viable strategy. However, in the case of extrapulmonary involvement, the implementation of systemic chemotherapy ought to be deliberated. Given the heightened potential for disease progression, this underscores the necessity for meticulous consideration during the development of therapeutic plans.

Bordetella spp. block eosinophil recruitment to suppress the generation of early mucosal protection

Bordetella spp. are respiratory pathogens equipped with immune evasion mechanisms. We previously characterized a Bordetella bronchiseptica mutant (RB50ΔbtrS) that fails to suppress host responses, leading to rapid clearance and long-lasting immunity against reinfection. This work revealed eosinophils as an exclusive requirement for RB50ΔbtrS clearance. We also show that RB50ΔbtrS promotes eosinophil-mediated B/T cell recruitment and inducible bronchus-associated lymphoid tissue (iBALT) formation, with eosinophils being present throughout iBALT for Th17 and immunoglobulin A (IgA) responses. Finally, we provide evidence that XCL1 is critical for iBALT formation but not maintenance, proposing a novel role for eosinophils as facilitators of adaptive immunity against B. bronchiseptica. RB50ΔbtrS being incapable of suppressing eosinophil effector functions illuminates active, bacterial targeting of eosinophils to achieve successful persistence and reinfection. Overall, our discoveries contribute to understanding cellular mechanisms for use in future vaccines and therapies against Bordetella spp. and extension to other mucosal pathogens.

The effect of Toll-like receptor agonists on the immunogenicity of MVA-SARS-2-S vaccine after intranasal administration in mice.

Modified Vaccinia virus Ankara (MVA) represents a promising vaccine vector for respiratory administration to induce protective lung immunity including tertiary lymphoid structure, the bronchus-associated lymphoid tissue (BALT). However, MVA expressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein (MVA-SARS-2-S) required prime-boost administration to induce high titers of anti-Spike antibodies in serum and bronchoalveolar lavage (BAL). As the addition of adjuvants enables efficient tailoring of the immune responses even to live vaccines, we tested whether Toll-like receptor (TLR)-agonists affect immune responses induced by a single dose of intranasally applied MVA-SARS-2-S. We intranasally immunized C57BL/6 mice with MVA-SARS-2-S vaccine in the presence of either TLR3 agonist polyinosinic polycytidylic acid [poly(I:C)], TLR4 agonist bacterial lipopolysaccharide (LPS) from Escherichia coli, or TLR9 agonist CpG oligodeoxynucleotide (CpG ODN) 1826. At different time-points after immunization, we analyzed induced immune responses using flow cytometry, immunofluorescent microscopy, and ELISA. TLR agonists had profound effects on MVA-SARS-2-S-induced immune responses. At day 1 post intranasal application, the TLR4 agonist significantly affected MVA-induced activation of dendritic cells (DCs) within the draining bronchial lymph nodes, increasing the ratio of CD11b+CD86+ to CD103+CD86+ DCs. Nevertheless, the number of Spike-specific CD8+ T cells within the lungs at day 12 after vaccination was increased in mice that received MVA-SARS-2-S co-administered with TLR3 but not TLR4 agonists. TLR9 agonist did neither significantly affect MVA-induced DC activation nor the induction of Spike-specific CD8+ T cells but reduced both number and size of bronchus-associated lymphoid tissue. Surprisingly, the addition of all TLR agonists failed to boost the levels of Spike-specific antibodies in serum and bronchoalveolar lavage. Our study indicates a potential role of TLR-agonists as a tool to modulate immune responses to live vector vaccines. Particularly TLR3 agonists hold a promise to potentiate MVA-induced cellular immune responses. On the other hand, additional research is necessary to identify optimal combinations of agonists that could enhance MVA-induced humoral responses.

Lung and Heart Biology of the Dp16 Mouse Model of down Syndrome: Implications for Studying Cardiopulmonary Disease.

(1) Background: We sought to investigate the baseline lung and heart biology of the Dp16 mouse model of Down syndrome (DS) as a prelude to the investigation of recurrent respiratory tract infection. (2) Methods: In controls vs. Dp16 mice, we compared peripheral blood cell and plasma analytes. We examined baseline gene expression in lungs and hearts for key parameters related to susceptibility of lung infection. We investigated lung and heart protein expression and performed lung morphometry. Finally, and for the first time each in a model of DS, we performed pulmonary function testing and a hemodynamic assessment of cardiac function. (3) Results: Dp16 mice circulate unique blood plasma cytokines and chemokines. Dp16 mouse lungs over-express the mRNA of triplicated genes, but not necessarily corresponding proteins. We found a sex-specific decrease in the protein expression of interferon α receptors, yet an increased signal transducer and activator of transcription (STAT)-3 and phospho-STAT3. Platelet-activating factor receptor protein was not elevated in Dp16 mice. The lungs of Dp16 mice showed increased stiffness and mean linear intercept and contained bronchus-associated lymphoid tissue. The heart ventricles of Dp16 mice displayed hypotonicity. Finally, Dp16 mice required more ketamine to achieve an anesthetized state. (4) Conclusions: The Dp16 mouse model of DS displays key aspects of lung heart biology akin to people with DS. As such, it has the potential to be an extremely valuable model of recurrent severe respiratory tract infection in DS.

Very low-dose radiotherapy for extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue

Extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue (BALT) is a rare cancer for which optimal treatment strategies are undefined. Retrospective analyses suggest excellent outcomes with surgical resection for localized BALT lymphoma; however, the role of radiotherapy remains underexplored. We report the largest-to-date single-center analysis of 13 primary BALT lymphoma patients treated with radiotherapy. Of 15 treated lesions, we report a 100% response rate with complete response (CR) achieved in 67% of lesions. Among 10 lesions treated with very low-dose radiotherapy (VLDRT; 4 Gray [Gy]), 6 (60%) achieved a CR; among 5 lesions treated with full-dose radiotherapy (24–36 Gy), 4 (80%) achieved a CR. There were no local recurrences. Only one patient, treated with 30 Gy, developed an acute grade 3/4 toxic effect. There were no events of radiation-induced secondary malignancies. Our institutional experience indicates that radiotherapy, including VLDRT, is a safe and effective treatment for primary BALT lymphoma.

Histological and immunohistochemical characterization of mucosa-associated lymphoid tissue and antigen-presenting cells in trachea and lung of cattle.

The presence of bronchus-associated lymphoid tissue (BALT) and its structural components has been described in different healthy animal species and in animals with diseases of the respiratory tract. In contrast to normal mammals, BALT is absent in healthy human adult lungs, but has been found in the lungs of children. The histological characteristics of organized mucosa-associated lymphoid tissue (MALT), its subsets of immune cells and their in situ distribution in the lung of healthy subadult and adult cattle shows close similarities with BALT in humans and other animal species such as sheep, horses and pigs. This study clearly demonstrates that organized MALT also occurs in the tracheal mucosa of cattle. The absence of tracheal MALT and BALT in calves suggest that these structures are not constitutive. In the mucosa of bovine trachea, bronchi and bronchioli, MHC II+ and CD11c+ dendritic cells (DCs) are located in the epithelium and in the lamina propria mucosae. These DCs are already present in calves soon after birth. Examination of tangential epithelial sheets shows that in the bovine tracheal epithelium, like in man and rat, a dense network of MHC II+ and CD11c+ DCs exists and that their number is considerably higher than in conventional transverse sections. In the bovine tracheal and bronchial epithelium, MHC II+ DCs are extending their dendrites towards the lumen indicating that these DCs possibly are involved in sampling of luminal antigens. The presence of significantly higher numbers of MHC II+ DCs in the tracheal and bronchial/bronchiolar mucosa of older cattle in than in calves possibly results from local stimulation with exogenous antigens during postnatal life. Detection of DCs expressing the costimulatory molecules CD80 and CD86 in calves and cattle suggests maturation of DCs, which is most likely induced by stimulation with exogenous antigens.

Smoking exposure-induced bronchus-associated lymphoid tissue in donor lungs does not prevent tolerance induction after transplantation

The presence of bronchus-associated lymphoid tissue (BALT) in donor lungs has been suggested to accelerate graft rejection after lung transplantation. Although chronic smoke exposure can induce BALT formation, the impact of donor cigarette use on alloimmune responses after lung transplantation is not well understood. Here, we show that smoking-induced BALT in mouse donor lungs contains Foxp3+ T cells and undergoes dynamic restructuring after transplantation, including recruitment of recipient-derived leukocytes to areas of pre-existing lymphoid follicles and replacement of graft-resident donor cells. Our findings from mouse and human lung transplant data support the notion that a donor’s smoking history does not predispose to acute cellular rejection or prevent the establishment of allograft acceptance with comparable outcomes to nonsmoking donors. Thus, our work indicates that BALT in donor lungs is plastic in nature and may have important implications for modulating proinflammatory or tolerogenic immune responses following transplantation.

Respiratory form of infectious rhinotracheitis: Analysis of immunomorphological reactions

The concentration of cattle in limited areas, nutritional disorders, and imbalance of micro- and macroelements contribute to suppression of natural resistance of the organism, insufficient live weight gain, leading to the growth of infectious diseases of young animals with high rates of forced slaughter and cattle mortality. The source of the causative agent of rhinotracheitis infection – Bovine alphaherpesvirus 1 hinders the development of the livestock industry, thus, it is necessary to search for possible approaches to prevent and control this infection. The purpose of the research is to determine the immunomorphological changes in the lymphoid tissue of the trachea and bronchial system, in the regional lymph nodes of the lungs and in the spleen in calves naturally affected by infectious rhinotracheitis. The experimental studies were based on the research of immunomorphological reactions in lymphoid tissue during infection of young cattle with Bovine alphaherpesvirus 1, using polymerase chain reaction, histological and immunohistochemical methods. According to the results, it was established that hyperplasia of tracheaassociated lymphoid tissue was observed in the trachea, and hyperplasia of bronchial-associated lymphoid tissue was observed in the lungs; the affected areas of the trachea and lungs were infiltrated with lymphocytes, macrophages and plasma cells. The immunomorphological reactions of regional lymph nodes demonstrate hyperplasia of B- and T-dependent zones, and in the spleen – hyperplasia of T-dependent zones of the white pulp. Thus, immunocompetent cells of lymphoid tissue associated with B- and T-dependent areas of the trachea, bronchial system of the lungs and regional lymph nodes of the lungs, and with T-dependent areas of the spleen, are directly involved in the pathogenesis of infectious rhinotracheitis of respiratory type calves. Antibacterial therapy with antibiotics destroys pathogenic and normal flora in the intestine, but they are not effective enough on viral infection, therefore, production trials of effective means of specific prophylaxis and vaccination are the primary task of veterinary medicine

Formation of bronchus-associated lymphoid tissue (BALT) for early life immune protection.

Formation of bronchus-associated lymphoid tissue (BALT) for early life immune protection.

Induction of bronchus-associated lymphoid tissue is an early life adaptation for promoting human B cell immunity.

Infants and young children are more susceptible to common respiratory pathogens than adults but can fare better against novel pathogens like severe acute respiratory syndrome coronavirus 2. The mechanisms by which infants and young children mount effective immune responses to respiratory pathogens are unknown. Through investigation of lungs and lung-associated lymph nodes from infant and pediatric organ donors aged 0-13 years, we show that bronchus-associated lymphoid tissue (BALT), containing B cell follicles, CD4+ T cells and functionally active germinal centers, develop during infancy. BALT structures are prevalent around lung airways during the first 3 years of life, and their numbers decline through childhood coincident with the accumulation of memory T cells. Single-cell profiling and repertoire analysis reveals that early life lung B cells undergo differentiation, somatic hypermutation and immunoglobulin class switching and exhibit a more activated profile than lymph node B cells. Moreover, B cells in the lung and lung-associated lymph nodes generate biased antibody responses to multiple respiratory pathogens compared to circulating antibodies, which are mostly specific for vaccine antigens in the early years of life. Together, our findings provide evidence for BALT as an early life adaptation for mobilizing localized immune protection to the diverse respiratory challenges during this formative life stage.

Oral toxicological study of titanium dioxide nanoparticles with a crystallite diameter of 6 nm in rats

BackgroundThough titanium dioxide (TiO2) is generally considered to have a low impact in the human body, the safety of TiO2 containing nanosized particles (NPs) has attracted attention. We found that the toxicity of silver NPs markedly varied depending on their particle size, as silver NPs with a diameter of 10 nm exhibited fatal toxicity in female BALB/c mice, unlike those with diameters of 60 and 100 nm. Therefore, the toxicological effects of the smallest available TiO2 NPs with a crystallite size of 6 nm were examined in male and female F344/DuCrlCrlj rats by repeated oral administration of 10, 100, and 1000 mg/kg bw/day (5/sex/group) for 28 days and of 100, 300, and 1000 mg/kg bw/day (10/sex/group) for 90 days.ResultsIn both 28- and 90-day studies, no mortality was observed in any group, and no treatment-related adverse effects were observed in body weight, urinalysis, hematology, serum biochemistry, or organ weight. Histopathological examination revealed TiO2 particles as depositions of yellowish-brown material. The particles observed in the gastrointestinal lumen were also found in the nasal cavity, epithelium, and stromal tissue in the 28-day study. In addition, they were observed in Peyer's patches in the ileum, cervical lymph nodes, mediastinal lymph nodes, bronchus-associated lymphoid tissue, and trachea in the 90-day study. Notably, no adverse biological responses, such as inflammation or tissue injury, were observed around the deposits. Titanium concentration analysis in the liver, kidneys, and spleen revealed that TiO2 NPs were barely absorbed and accumulated in these tissues. Immunohistochemical analysis of colonic crypts showed no extension of the proliferative cell zone or preneoplastic cytoplasmic/nuclear translocation of β-catenin either in the male or female 1000 mg/kg bw/day group. Regarding genotoxicity, no significant increase in micronucleated or γ-H2AX positive hepatocytes was observed. Additionally, the induction of γ-H2AX was not observed at the deposition sites of yellowish-brown materials.ConclusionsNo effects were observed after repeated oral administration of TiO2 with a crystallite size of 6 nm at up to 1000 mg/kg bw/day regarding general toxicity, accumulation of titanium in the liver, kidneys, and spleen, abnormality of colonic crypts, and induction of DNA strand breaks and chromosomal aberrations.

A Retrospective Study of the Clinical, Radiological, and Pathological Characteristics of Patients with Interstitial Pneumonia Preceding Rheumatoid Arthritis.

Objective Interstitial lung disease (ILD) is the most critical manifestation in patients with rheumatoid arthritis (RA). In some cases, ILD may appear before the RA onset. Some patients with an initial diagnosis of idiopathic interstitial pneumonia (IIPs) develop RA; however, few studies have reported on its features, and the details remain unknown. In the present study, the clinical, radiological, and pathological features were evaluated in patients with ILD preceding RA. Methods The clinical, radiological, and pathological features of patients with ILD preceding RA were retrospectively reviewed using the medical records. Patients Ten patients with ILD preceding RA out of 883 IIP patients who underwent a surgical lung biopsy at our hospital from 2004 to 2018 were retrospectively examined. Results The median patient age was 59 (range 50-76) years old, and 7 of the patients were women. The median time from the ILD diagnosis to the RA onset was 50 (range 33-65) months. Regarding the high-resolution computed tomography pattern, the "indeterminate for UIP" pattern was the most popular, and cysts were seen in all cases. Attenuation around the cyst was prominent. Pathological findings showed plasma cell infiltration, bronchus-associated lymphoid tissue (BALT), and bronchiolitis in the lobules. Cellular and destructive bronchiolitis was noticeable in many patients with ILD preceding RA and contributed to the destruction and dilation of the bronchiole. Conclusion In ILD patients with IIP, radiological and pathological findings with increased attenuation around the cysts, prominent inflammatory cell infiltration (especially in plasma cells), an increase in the BALT number, and cellular and destructive bronchiolitis might serve as helpful RA development indicators.

A single‐center experience of low‐dose radiotherapy for primary extranodal marginal zone lymphoma of bronchus‐associated lymphoid tissue (BALT)

Introduction: Extranodal marginal zone lymphoma of bronchus-associated lymphoid tissue (BALT) is a rare cancer for which optimal treatment strategies are not well defined. Retrospective analyses show equivalent or superior outcomes with surgical resection compared to systemic therapy or active surveillance. Despite a well established role for radiotherapy in the management of other types of extranodal marginal zone lymphoma (MZL), its role in BALT lymphoma is underexplored. Methods: We screened 153 patients with a diagnosis of primary BALT lymphoma treated at a single institution from 1995 to 2022. Inclusion criteria comprised patients aged 18 years or older, histologically confirmed BALT lymphoma, and receipt of radiotherapy at initial presentation or disease progression/recurrence. We excluded patients with synchronous evidence of lymphoma involving non-thoracic extranodal sites and/or lymphadenopathy outside of the mediastinum and hilum, as these patients might represent MZL with secondary lung involvement as opposed to primary BALT lymphoma. All patients underwent baseline PET/CT staging. We extracted patient, tumor, imaging, and treatment characteristics from the electronic medical record. We defined active surveillance as at least 3 months of follow up prior to initiating active therapy combined with documentation of this plan in the medical record. We assessed treatment response using the RECIL 2017 criteria. Results: We report the largest to date single-center retrospective analysis of 13 patients (median age 67 years, range 33–84 years) with localized BALT lymphoma treated with radiotherapy. The median tumor size was 3.6 cm (range 0.8–8.2 cm) with a median SUV of 3.9 (range 1.3–11.4). Most patients (n = 8, 62%) received radiotherapy for BALT lymphoma after failing first-line treatment, including active surveillance (n = 3), surgical resection (n = 2), or systemic therapy (n = 3). Of 15 irradiated lesions, most (n = 10, 67%) received very low-dose radiotherapy (VLRDT) of 4 Gy (range 4–36 Gy). With a median follow-up of >50 months, only 3 patients experienced progression of disease, none within the irradiated field (1 following VLDRT and 2 following full-dose RT). Among all treated lesions, the overall response rate was 100% (n = 5, 33% partial response [PR] and n = 10, 67% complete response [CR]). Among 10 lesions treated with VLDRT, 6 (60%) achieved CR; among 5 lesions treated with full-dose RT, 4 (80%) achieved CR. There were no events of secondary lung cancers within or in proximity to the irradiated field. Conclusions: Radiotherapy, including VLDRT, is a feasible, well tolerated, non-invasive and effective treatment strategy for primary BALT lymphoma that can be considered in both the upfront and recurrent treatment settings. The research was funded by: National Cancer Institute (P30 CA008748) Keywords: Extranodal non-Hodgkin lymphoma, Indolent non-Hodgkin lymphoma No conflicts of interests pertinent to the abstract.

Human lung virtual histology by multi-scale x-ray phase-contrast computed tomography

Objectives. As the central organ of the respiratory system, the human lung is responsible for supplying oxygen to the blood, which reaches the erythrocytes by diffusion through the alveolar walls and is then distributed throughout the body. By exploiting the difference in electron density detected by a phase shift in soft tissue, high-resolution x-ray phase-contrast computed tomography (XPCT) can resolve biological structures in a sub-μm range, shedding new light on the three-dimensional structure of the lungs, physiological functions and pathological mechanisms. Approach. This work presents both synchrotron and laboratory XPCT results of postmortem tissue from autopsies and biopsies embedded with various preparation protocols such as precision-cut lung slices, cryogenically fixed lung tissue, as well as paraffin and alcohol fixed tissue. The selection of pathological abnormalities includes channel of Lambert, bronchus-associated lymphoid tissue and alveolar capillary dysplasia with misalignment of pulmonary veins. Subsequently, quantification and visualization approaches are presented. Main results. The overall high image quality even of in-house XPCT scans for the case of FFPE biopsies can be exploited for a wide range of pulmonary pathologies and translated to dedicated and optimized instrumentation which could be operated in clinical setting. By using synchrotron radiation, contrast can be further increased to resolve sub-μm sized features down to the sub-cellular level. The results demonstrate that a wide range of preparation protocols including sample mounting in liquids can be used. Significance. With XPCT, poorly understood 3D structures can be identified in larger volume overview and subsequently studied in more detail at higher resolution. With the full 3D structure, the respective physiological functions of airways or vascular networks, and the different pathophysiologic mechanisms can be elucidated or at least underpinned with structural data. Moreover, synchrotron data can be used to validate laboratory protocols and provide ground truth for standardizing the method.

Prior infection exposure alters the immune response at homeostasis and following SARS-CoV-2 vaccination and experimental infection in laboratory mice.

Abstract Variable translatability represents a major criticism of the use of mouse models for preclinical research. Lack of exposure to most endogenous murine pathogens results in natural immune responses of specific pathogen free (SPF) lab mice to more closely resemble that of newborns rather than adult humans. Recently, the effects of prior infection exposure (PIE) on immune maturation and responses have been increasingly explored in mice. Here, we employed a PIE model where BALB/c mice underwent sequential subclinical infection with four pathogens at two-week intervals: 1) MHV-68, a gammaherpesvirus, 2) MCMV, a betaherpesvirus, 3) influenza virus, and 4) Heligmosomoides polygyrus, a murine intestinal nematode. Four-to-12 weeks following H. polygyrus infection, mice were sacrificed, spleens were collected for flow cytometric analysis, and lungs were collected for histological evaluation. Compared to SPF mice, PIE spleens demonstrated increased proportions of CD4+ and CD8+ T effector memory cells. In the lungs, PIE induced the formation of bronchus-associated lymphoid tissue and increased infiltration of CD4+ and CD8+ T cells. Following vaccination against SARS-CoV-2 with either a protein subunit-based (S2P) or inactivated (iCoV2) vaccine, iCoV2-, but not S2P-, vaccinated PIE mice demonstrated significantly reduced serum neutralizing antibodies compared to SPF mice. Following infection with SARS-CoV-2-MA10, PIE mice showed a mild reduction in mortality, weight loss, and lung titers, and a significant increase in lung T cell infiltration compared to SPF mice. These data indicate that PIE results in adaptive immune maturation but has a variable effect on SARS-CoV-2-specific vaccine responses and clinical outcomes in mice. This work was supported by the NIH (K01OD026529, T32AI007151, U19AI100625, U19AI09680), an AAI Careers in Immunology Fellowship Award, an UNC School of Medicine Junior Investigator Development Award, and a NCTraCS and Emerging Challenges in Biomedical Research COVID Pilot Award.