Pulmonary Granulomas Research Articles

Pulmonary Hyalinizing Granuloma in a Veteran With Latent Tuberculosis and Agent Orange Exposure

Pulmonary Hyalinizing Granuloma in a Veteran With Latent Tuberculosis and Agent Orange Exposure

Mycobacterium tuberculosis ESAT-6 is a leukocidin causing Ca2+ influx, necrosis and neutrophil extracellular trap formation.

Mycobacterium tuberculosis infection generates pulmonary granulomas that consist of a caseous, necrotic core surrounded by an ordered arrangement of macrophages, neutrophils and T cells. This inflammatory pathology is essential for disease transmission and M. tuberculosis has evolved to stimulate inflammatory granuloma development while simultaneously avoiding destruction by the attracted phagocytes. The most abundant phagocyte in active necrotic granulomas is the neutrophil. Here we show that the ESAT-6 protein secreted by the ESX-1 type VII secretion system causes necrosis of the neutrophils. ESAT-6 induced an intracellular Ca2+ overload followed by necrosis of phosphatidylserine externalised neutrophils. This necrosis was dependent upon the Ca2+ activated protease calpain, as pharmacologic inhibition prevented this secondary necrosis. We also observed that the ESAT-6 induced increase in intracellular Ca2+, stimulated the production of neutrophil extracellular traps characterised by extruded DNA and myeloperoxidase. Thus we conclude that ESAT-6 has a leukocidin function, which may facilitate bacterial avoidance of the antimicrobial action of the neutrophil while contributing to the maintenance of inflammation and necrotic pathology necessary for granuloma formation and TB transmission.

Limited activity of clofazimine as a single drug in a mouse model of tuberculosis exhibiting caseous necrotic granulomas.

New drugs and drugs with a novel mechanism of action are desperately needed to shorten the duration of tuberculosis treatment, to prevent the emergence of drug resistance, and to treat multiple-drug-resistant strains of Mycobacterium tuberculosis. Recently, there has been renewed interest in clofazimine (CFZ). In this study, we utilized the C3HeB/FeJ mouse model, possessing highly organized, hypoxic pulmonary granulomas with caseous necrosis, to evaluate CFZ monotherapy in comparison to results with BALB/c mice, which form only multifocal, coalescing cellular aggregates devoid of caseous necrosis. While CFZ treatment was highly effective in BALB/c mice, its activity was attenuated in the lungs of C3HeB/FeJ mice. This lack of efficacy was directly related to the pathological progression of disease in these mice, since administration of CFZ prior to the formation of hypoxic, necrotic granulomas reconstituted bactericidal activity in this mouse strain. These results support the continued use of mouse models of tuberculosis infection which exhibit a granulomatous response in the lungs that more closely resembles the pathology found in human disease.

Recombinant paracoccin reproduces the biological properties of the native protein and induces protective Th1 immunity against Paracoccidioides brasiliensis infection.

BackgroundParacoccin is a dual-function protein of the yeast Paracoccidioides brasiliensis that has lectin properties and N-acetylglucosaminidase activities. Proteomic analysis of a paracoccin preparation from P. brasiliensis revealed that the sequence matched that of the hypothetical protein encoded by PADG-3347 of isolate Pb-18, with a polypeptide sequence similar to the family 18 endochitinases. These endochitinases are multi-functional proteins, with distinct lectin and enzymatic domains.Methodology/principal findingsThe multi-exon assembly and the largest exon of the predicted ORF (PADG-3347), was cloned and expressed in Escherichia coli cells, and the features of the recombinant proteins were compared to those of the native paracoccin. The multi-exon protein was also used for protection assays in a mouse model of paracoccidioidomycosis.Conclusions/SignificanceOur results showed that the recombinant protein reproduced the biological properties described for the native protein—including binding to laminin in a manner that is dependent on carbohydrate recognition—showed N-acetylglucosaminidase activity, and stimulated murine peritoneal macrophages to produce high levels of TNF-α and nitric oxide. Considering the immunomodulatory potential of glycan-binding proteins, we also investigated whether prophylactic administration of recombinant paracoccin affected the course of experimental paracoccidioidomycosis in mice. In comparison to animals injected with vehicle (controls), mice treated with recombinant paracoccin displayed lower pulmonary fungal burdens and reduced pulmonary granulomas. These protective effects were associated with augmented pulmonary levels of IL-12 and IFN-γ. We also observed that injection of paracoccin three days before challenge was the most efficient administration protocol, as the induced Th1 immunity was balanced by high levels of pulmonary IL-10, which may prevent the tissue damage caused by exacerbated inflammation. The results indicated that paracoccin is the protein encoded by PADG-3347, and we propose that this gene and homologous proteins in other P. brasiliensis strains be called paracoccin. We also concluded that recombinant paracoccin confers resistance to murine P. brasiliensis infection by exerting immunomodulatory effects.

Comparison of gene expression of immune mediators in lung and pulmonary lymph node granulomas from cattle experimentally infected with Mycobacterium bovis

The cellular infiltrates and macrophage activation pathways may differ in granulomas found in the lungs and pulmonary lymph nodes of cattle infected with Mycobacterium bovis. The aim of this study was to compare the histopathology and gene expression profiles of cytokines and immune mediators for cattle which had these lesions in both sites. Ten Friesian-cross, 15–16 month old cattle were challenged intratracheally with 5×103CFU of virulent M. bovis and killed and necropsied at 28 weeks after infection. Seven animals were found to have gross TB granulomas in both their lungs and pulmonary lymph nodes (PLN) and these lesions were fully encapsulated with central necrosis and mineralisation. Neutrophil infiltration was clearly involved in granuloma in lung whereas neutrophils were limited in lesions of PLN. Comparisons were made of immune mediators from these two sites from the same animals as well as those between lesioned PLN tissues and non-lesioned prescapular lymph nodes (PSLN). Gene expressions of the immune mediators were normalised using a housekeeping gene (U1), a monocyte/macrophage marker (CD14) and a common leucocyte marker (CD45). mRNA expression of IFN-γ, IL-17A, IRF5(1) and arginase 1 (Arg1) was significantly up-regulated in lung compared to that for PLN (p<0.05), while mRNA expression of IFN-γ, IL-12p40, TNF-α and iNOs for PLN was significantly higher than that for PSLN (p<0.05). In addition, IL-10 mRNA expression was significantly higher for lung compared to PLN when normalised for CD45 (p<0.05). The results suggested that the stronger proinflammatory immune response in the lesioned lung may be a consequence of enhanced expression of IRF5 promoting IFN-γ and IL-17 production. In contrast, Arg1 expression in the lungs could facilitate the infection through competing with iNOs for l-arginine, preventing generation of nitric oxide for clearance of M. bovis infection.

Early Changes by 18 Fluorodeoxyglucose Positron Emission Tomography Coregistered with Computed Tomography Predict Outcome after Mycobacterium tuberculosis Infection in Cynomolgus Macaques

Cynomolgus macaques infected with low-dose Mycobacterium tuberculosis develop both active tuberculosis and latent infection similar to those of humans, providing an opportunity to study the clinically silent early events in infection. (18)Fluorodeoxyglucose radiotracer with positron emission tomography coregistered with computed tomography (FDG PET/CT) provides a noninvasive method to measure disease progression. We sought to determine temporal patterns of granuloma evolution that distinguished active-disease and latent outcomes. Macaques (n = 10) were infected with low-dose M. tuberculosis with FDG PET/CT performed during infection. At 24 weeks postinfection, animals were classified as having active disease (n = 3) or latent infection (n = 6), with one "percolator" monkey. Imaging characteristics (e.g., lesion number, metabolic activity, size, mineralization, and distribution of lesions) were compared among active and latent groups. As early as 3 weeks postinfection, more pulmonary granulomas were observed in animals that would later develop active disease than in those that would develop latent infection. Over time, new lesions developed in active-disease animals but not in latent animals. Granulomas and mediastinal lymph nodes from active-disease but not latent animals consistently increased in metabolic activity at early time points. The presence of fewer lesions at 3 weeks and the lack of new lesion development in animals with latent infection suggest that innate and rapid adaptive responses are critical to preventing active tuberculosis. A greater emphasis on innate responses and/or rapid recruitment of adaptive responses, especially in the airway, should be emphasized in newer vaccine strategies.

Perturbation of pulmonary immune functions by carbon nanotubes and susceptibility to microbial infection

Occupational and environmental pulmonary exposure to carbon nanotubes (CNT) is considered to be a health risk with a very low threshold of tolerance as determined by the United States Center for Disease Control. Immortalized airway epithelial cells exposed to CNTs show a diverse range of effects including reduced viability, impaired proliferation, and elevated reactive oxygen species generation. Additionally, CNTs inhibit internalization of targets in multiple macrophage cell lines. Mice and rats exposed to CNTs often develop pulmonary granulomas and fibrosis. Furthermore, CNTs have immunomodulatory properties in these animal models. CNTs themselves are proinflammatory and can exacerbate the allergic response. However, CNTs may also be immunosuppressive, both locally and systemically. Studies that examined the relationship of CNT exposure prior to pulmonary infection have reached different conclusions. In some cases, pre-exposure either had no effect or enhanced clearance of infections while other studies showed CNTs inhibited clearance. Interestingly, most studies exploring this relationship use pathogens which are not considered primary pulmonary pathogens. Moreover, harmony across studies is difficult as different types of CNTs have dissimilar biological effects. We used Pseudomonas aeruginosa as model pathogen to study how helical multi-walled carbon nanotubes (HCNTs) affected internalization and clearance of the pulmonary pathogen. The results showed that, although HCNTs can inhibit internalization through multiple processes, bacterial clearance was not altered, which was attributed to an enhanced inflammatory response caused by pre-exposure to HCNTs. We compare and contrast our findings in relation to other studies to gauge the modulation of pulmonary immune response by CNTs.

Zapalenie ziarniniakowe płuc jako powikłanie leczenia dopęcherzowymi wlewkami BCG—Opis przypadku

BCG (Bacillus Calmette-Guerin) comprises an attenuated strain of Mycobacterium bovis and is used for vaccination against tuberculosis. An additional use of BCG is for immunotherapy of cancer in which the vaccine is administered intravesically for the treatment of superficial bladder cancer. The efficacy of immunotherapy with BCG in the prevention of recurrence is estimated at 70-99%, which is higher than for local chemotherapy. The most frequent complications of such treatment include fever and urinary bladder inflammation, while serious complications of haematogenous organ inflammation, especially inflammation of the lungs with the formation of pulmonary caseosus granulomas, are rarely seen. The authors reported a case of a 68-year-old man who was treated with intravesical BCG instillations due to a superficial bladder cancer. The patient underwent transurethral resection of bladder cancer and then periodically received intravesical BCG instillations. A few days after one instillation, systemic symptoms with a high fever appeared. Further examinations showed features of hepatitis and spread pulmonary changes. The patient underwent videothoracoscopy, and a fragment of lung parenchyma was collected. The histopathological examination revealed the presence of granulomas with central caseosus necrosis. Suspecting BCG infection, diagnostics were enhanced to include bacteriological and genetic tests for the presence of acid-resistant bacilli, which finally gave negative results. The authors diagnosed granulomatous pneumonia as a complication of intravesical BCG immunotherapy. Treatment with antituberculous drugs was initiated. After completing pharmacological treatment, radiological control was performed, which showed significant but not complete remission of pulmonary changes.

Pulmonary hyalinizing granuloma involving the diaphragm and the pericardium

Pulmonary hyalinizing granuloma (PHG) is a rare disorder and is a pertinent differential for lung diseases with multiple pulmonary nodules. Natural history of this disease is not known. Although the usual course is benign, a close follow-up of these cases is necessary. We herein report a case of PHG involving the diaphragm and the heart, detected on autopsy in a 57-year-old male who suffered a road traffic accident.

Potential Occupational Risks Associated with Pulmonary Toxicity of Carbon Nanotubes.

Given their remarkable properties, carbon nanotubes (CNTs) have made their way through various industrial and medicinal applications and the overall production of CNTs is expected to grow rapidly in the next few years, thus requiring an additional recruitment of workers. However, their unique applications and desirable properties are fraught with concerns regarding occupational exposure. The concern about worker exposure to CNTs arises from the results of recent animal studies. Short-term and sub-chronic exposure studies in rodents have shown consistent adverse health effects such as pulmonary inflammation, granulomas, fibrosis, genotoxicity and mesothelioma after inhalation or instillation of several types of CNTs. Furthermore, physicochemical properties of CNTs such as dispersion, functionalization and particle size can significantly affect their pulmonary toxicity. Risk estimates from animal studies necessitate implementation of protective measures to limit worker exposure to CNTs. Information on workplace exposure is very limited, however, studies have reported that CNTs can be aerosolized and attain respirable airborne levels during synthesis and processing activities in the workplace. Quantitative risk assessments from sub-chronic animal studies recommend the health-based need to reduce exposures below the recommended exposure limit of 1 µg/m3. Practice of prevention measures including the use of engineering controls, personal protective equipment, health surveillance program, safe handling and use, as well as worker training can significantly minimize worker exposure and improve worker health and safety.

Immunophenotype of lung granulomas in HIV and non-HIV associated tuberculosis

OBJECTIVE: To describe the immunophenotype of pulmonary TB granulomas from autopsied patients with tuberculosis (TB group) and from HIV patients with tuberculosis (TB/HIV group), and to identify the Mycobacterium species using polymerase chain reaction (PCR) technique. METHODS: Lung samples of 15 TB group patients and 23 TB/HIV group patients were selected. Histopathologic analyses and immunohistochemistry tests were performed to describe the granulomas and to detect the infectious agent (anti-BCG). CD4, CD8, CD20 and CD68 were evaluated to characterize the immnophenotype of the granulomas. Polymerase Chain Reaction was performed to identify the mycobacterium species. RESULTS: CD4 + T lymphocytes were the cells with highest density in the TB group, whereas CD68 cells exhibited the highest density in the TB/HIV group. Comparison between groups showed that the CD4 + T density was significantly higher in the TB patients; whereas, CD68 density was significantly higher in the TB/HIV patients. M. tuberculosis was identified in 8 cases of each group; M. avium was only found in one case of the TB/HIV group. CONCLUSION: With the advent of AIDS, the immunological profile of TB has changed. This may be associated with the depletion of CD4 + T lymphocytes in lung granulomas. M. tuberculosis was the major etiological agent of TB in both groups.

Thallium-201-scintigraphy-positive recurrent pulmonary hyalinising granuloma with elevated IgG4 [Correspondence

Thallium-201-scintigraphy-positive recurrent pulmonary hyalinising granuloma with elevated IgG4 [Correspondence

肺外突出性の増殖を示したPulmonary Hyalinizing Granulomaの1例

肺外突出性の増殖を示したPulmonary Hyalinizing Granulomaの1例

Pulmonary Granuloma Associated with Non-tuberculous Mycobacteriosis Occurring at the Staple Line After Segmentectomy for Lung Cancer: Report of a Case

Pulmonary Granuloma Associated with Non-tuberculous Mycobacteriosis Occurring at the Staple Line After Segmentectomy for Lung Cancer: Report of a Case

Inflammatory markers and pulmonary granuloma infiltration in sarcoidosis

Previous studies have demonstrated increases of inflammatory mediators in sarcoidosis while epidemiological studies have also demonstrated an association with increased fungi exposure. This study measured the level of β-glucan in the lungs and of inflammatory mediators in serum, and correlated both with the extent of pulmonary granuloma infiltration. This is a cross-sectional study of 98 patients with sarcoidosis and 26 controls. β-glucan, a cell wall constituent of fungi, was measured in bronchoalveolar lavage. Inflammatory mediator levels were determined in serum. The extent of granuloma infiltration was estimated on the chest X-ray. Exposure to fungi at home was determined by taking air samples in bedrooms and analysing for the presence of β-N-acetylhexosaminidase. Significantly, higher levels of β-glucan were found in broncho-alveolar lavage in subjects with sarcoidosis as compared with controls. There were significant positive relationships between the extent of granuloma infiltration and the levels of the different inflammatory mediators, except for interleukin-10. Domestic fungal exposure was higher among subjects with sarcoidosis. This is the first time that a specific agent, previously suspected to be related to the risk of sarcoidosis, has been detected in the lung of subjects with sarcoidosis and related to the levels of inflammatory mediators and the degree of home exposure to fungi. The results suggest that exposure to fungi should be explored when investigating patients with sarcoidosis.

Pulmonary Necrotizing Granulomas of Unknown Cause: Clinical and Pathologic Analysis of 131 Patients With Completely Resected Nodules

The cause of pulmonary necrotizing granulomas is often unclear, even after histologic examination. Our aim was to determine the clinical significance of histologically unexplained necrotizing granulomas. Pulmonary necrotizing granulomas surgically resected at the Mayo Clinic (1994-2004) were retrieved and reviewed retrospectively. Cases in which a cause was evident at the time of initial histologic examination were excluded. The analysis cohort comprised 131 completely resected histologically unexplained pulmonary necrotizing granulomas. Clinical and laboratory information was abstracted from medical records, chest CT scans were reviewed, histologic slides were reexamined, and additional ancillary studies were performed in selected cases. A cause was determined on review in more than one-half of the histologically unexplained necrotizing granulomas (79 of 131, 60%) by reexamining histologic slides (47), incorporating the results of cultures (26), fungal serologies (14), and other laboratory studies (eight), and correlating histologic findings with clinical and radiologic information (13). Infections accounted for the majority (64 of 79), the most common being histoplasmosis (37) and nontuberculous mycobacterial infections (18). Noninfectious diagnoses (15 of 79) were rheumatoid nodule (five), granulomatosis with polyangiitis (Wegener) (five), sarcoidosis (four), and chronic granulomatous disease (one). Many cases remained unexplained even after extensive review (52 of 131, 40%). Most of these patients received no medical therapy and did not progress clinically or develop new nodules (median follow-up, 84 months). A cause, the most common being infection, can be established in many surgically resected pulmonary necrotizing granulomas that appear unexplained at the time of initial histologic diagnosis. Patients whose granulomas remain unexplained after a rigorous review have a favorable outcome. Most do not develop new nodules or progress clinically, even without medical therapy.

Roles of Th17 cells in pulmonary granulomas induced by Schistosoma japonicum in C57BL/6 mice

In schistosomiasis, limited information is available about the role of interleukin-17 (IL-17) in lung, despite the fact that this cytokine plays a crucial role during pro-inflammatory immune responses. In our study, we observed CD4+T cells changed after the infection. Furthermore, ELISA and FACS results revealed that Schistosomajaponicum infection could induce a large amount of IL-17 in mouse pulmonary lymphocytes. IL-17-producing cells, including Th17 cells, CD8+T (Tc) cells, γδT cells and natural killer T cells, was also associated with the development of lung inflammatory diseases. FACS results indicated that Th17 cell was the main source of IL-17 in the infected pulmonary lymphocytes after phorbol-12-myristate-13-acetate (PMA) and Ionomycin stimulation. Moreover, FACS results revealed that the percentage of Th17 cells continued to increase as over the course of S. japonicum infection. Additionally, cytokines co-expression results demonstrated that Th17 cells could express more IL-4 and IL-5 than IFN-γ. Reducing IL-17 activity by using anti-IL-17 ameliorated the damage and decreased infiltration of inflammatory cells in infected C57BL/6 mouse lungs. Collectively, these results suggest Th17 cells is the major IL-17-producing cells population and IL-17 contributes to pulmonary granulomatous inflammatory during the S. japonicum infection.

Pulmonary Hyalinizing Granuloma Detected in a Family Member after Confirmation of Tuberculosis in His Father

Pulmonary hyalinizing granuloma (PHG) is an uncommon lung disease that usually presents as bilateral multiple nodules, and more rarely as a solitary nodule. An exaggerated immune response to antigenic stimuli resulting from infection or an autoimmune process has been suggested as the cause of PHG. Here, we describe a rare case of solitary PHG that was detected in a family member after tuberculosis had been confirmed in his father, without any background of infectious disease or autoimmune abnormality.

Basophil depletion downregulates Schistosoma mansoni egg-induced granuloma formation

Granuloma formation around parasite eggs during schistosomal infection is considered to be controlled by Th2 cytokines. However, it is still controversial which cell populations are responsible for the host Th2 cytokine-dependent granuloma formation. Basophils have recently attracted attention because of their ability to produce large amounts of IL-4. Therefore, we investigated whether basophils play an essential role in the induction of granuloma formation induced by Schistosoma mansoni eggs. Together with our previous observation that basophil numbers increased markedly in the spleen at 7weeks postinfection, immunohistochemical staining using anti-mMCP8 monoclonal antibody (mAb) showed basophil infiltration in the granulomatous lesions formed around parasite eggs. To examine the roles of basophils more directly, we treated mice with anti-CD200R3 mAb to deplete basophils. Depletion of basophils resulted in a reduction of basophil number with concomitant downregulation of egg granuloma formation at 7weeks postinfection. Moreover, we observed a significant reduction in the size of egg granulomas formed in basophil-depleted mice in the pulmonary granuloma model. Taken together, these findings indicated that basophils are essential for S. mansoni egg-induced granuloma formation, and this may serve as a novel therapeutic target in ameliorating the pathology of schistosomiasis.

B Cell-Deficient Mice Display Enhanced Susceptibility to Paracoccidioides brasiliensis Infection

Paracoccidioidomycosis (PCM) is a chronic granulomatous disease caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. T helper 1 (Th1)-mediated immunity is primarily responsible for acquired resistance during P. brasiliensis infection. On the contrary, the susceptibility is associated with occurrence of type-2 immunity (Th2), which is characterized by IL-4 release, B cell activation, and production of antibodies. Although antibodies are frequently associated with severe PCM, it is not clear whether they contribute to susceptibility or merely constitute a marker of infection stage. Here, we assessed the function of B cells during experimental P. brasiliensis infection in mice, and our results showed that B cell-knockout (B(KO)) mice are more susceptible than their wild-type littermate controls (C57BL/6, WT). The B(KO) mice showed higher mortality rate, increased number of colony-forming units in the lungs, and larger granulomas than WT mice. In the absence of B cells, we observed high levels of IL-10, whereas IFN-γ, TNF-α, and IL-4 levels were similar between both groups. Finally, we showed that transference of WT immune serum to B(KO) mice resulted in diminished infiltration of inflammatory cells and better organization of the pulmonary granulomas. Taken together, these data suggest that B cells are effectively involved in the control of P. brasiliensis growth and organization of the granulomatous lesions observed during the experimental PCM.