Experimental pulmonary histoplasmosis and emphysema

Chronic pulmonary histoplasmosis often occurs in the setting of emphysema. However, it is unknown whether emphysema directly predisposes to the development of the necrotizing lesions of chronic pulmonary histoplasmosis. We evaluated this possibility using a murine model of pulmonary histoplasmosis. Using intratracheal inoculation of elastase, we induced pulmonary emphysema in Balb/c mice. When mice with emphysema were challenged intranasally with H. capsulatum (HC) yeast cells, the course of their disease was not significantly different from that of normal mice. Mice were also exposed to HC antigens by sublethal intranasal challenge with viable or heat-killed HC, or immunized with histoplasmin. Prior sublethal challenge with viable HC did not cause prolonged illness or increased mortality in the setting of emphysema. In contrast, such mice were protected against a severe rechallenge. Additional studies showed that intranasal administration of heat-killed HC or subcutaneous immunization with histoplasmal antigens had neither protective nor deleterious effects on the course of histoplasmosis. Therefore, in this murine model, we could not substantiate an interaction of underlying emphysema with acute primary or rechallenge pulmonary histoplasmosis.     

Immunological cross reactivity between Schistosoma mansoni and cholera toxin

Intranasal administration of schistosome antigens in combination with appropriate adjuvant may be an effective route for immunization against schistosomes, since the lungs represent an important site of elimination of schistosomulae. Our previous studies have shown that in mice intranasal administration of cholera toxin (CT) before infection with Schistosoma mansoni results in an enhancement of the worm burden in comparison to nontreated infected animals. In the present study, it was shown that mice treated intranasally with CT displayed high numbers of schistosome-reactive IgM-secreting cells in the spleen as well as high levels of schistosome-reactive serum IgM antibodies, whereas no significant immunological response against two other antigens, ovalbumin (OVA) or keyhole limpet haemocyanin (KLH) was noted. Sera from mice treated intranasally with CT recognized a 22 kDa antigen on SWAP blots. This band was not demonstrable after absorption of the sera with SWAP. These findings indicate a possible cross reactivity between cholera toxin and schistosome antigens. Further analysis by Western blot revealed that a 22 kDa antigen was detected on CT blots by sera from mice and humans infected with S. mansoni. This band was not demonstrable after absorption of the mouse or the human sera with CT. The 22 kDa cross reactive antigen was heat-stable. The antibodies against the 22 kDa antigen were only found within the IgM class but not within other Ig isotypes. Our findings also indicate that the 22 kDa antigen detected by anti- S. mansoni antibodies represents the A1 fragment of the cholera toxin .     

Divergent patterns of pulmonary blastomycosis induced by conidia and yeasts in athymic and euthymic mice

Athymic nude (nu/nu) mice are uniformly more susceptible than euthymic nu/+ mice to lethal infection with intranasally inoculated Blastomyces dermatitidis, whether infection is initiated by yeasts or conidia. Conidial infection requires a high inoculum size; the disease produced is prolonged and disseminated. Yeasts are infective at a low inoculum size and produce a rapidly fatal pneumonia. Thymus transplantation is more protective for conidia-infected than yeast-infected nude mice, presumably because the disease course is long enough for an effect to become demonstrable. Yeast inocula multiply more rapidly in the lungs than do conidial inocula. This may relate to the greater susceptibility of conidia to heterophils evoked in the airways, and the fact that yeasts derived from conidial inocula must survive in the face of an established inflammatory reaction. When yeasts and conidia are inoculated simultaneously, the disease produced is less severe than when yeasts are inoculated alone, presumably because of a more intense and diffuse inflammatory response engendered by the conidia. Suppression of conidia-derived yeast replication is demonstrable for at least 1 wk in nu/nu mice and for 2 to 3 wk in nu/+ mice. The latter delay appears attributable to the intact immune system in nu/+ mice, and the probability that cellular immunity limits the subsequent replication of yeasts. Eventually, the immune response fails to control yeast replication, and the mice succumb. These studies provide further insights into the role of the thymus in host defense against B. dermatitidis and the basis for the differential pace of infection when mice are infected with yeasts or conidia.     

Cave-associated acute pulmonary histoplasmosis in two Japanese returning from Mexico]

We report cases of cave-associated acute pulmonary histoplasmosis that occurred in two Japanese returning from Yucatan, Mexico. Patient 1 is a 35-year-old woman who worked in a bat-infested cave in Mexico for about 3 weeks. Almost all her colleagues had developed cough, fever and headache after 5 days in the cave. She was asymptomatic but her chest radiograph showed multiple nodules 5-10 mm in diameter throughout both lungs. The histoplasmal mycelial-phase complement fixation titer on admission was 1:16, and 1:128 one month later. Patient 2, the 53-year-old husband of patient 1, was also infected by histoplasma in the cave, and similar nodules were observed in his chest radiograph. His histoplasmal complement fixation titer did not elevate. To date, about 20 cases of pulmonary histoplasmosis have been reported in Japan. The number of imported mycoses in Japan is increasing, and histoplasmosis should be considered in the differential diagnosis of pulmonary nodules in travelers returning from endemic areas.     

Levamisole: Might It Be used in Treatment and Prevention of Atopic Diseases?

As an antihelmintic and Th₁‐biased immunostimulant, levamisole has been used to restore impaired cell mediated immunity. We sought to explore whether the Th₁ driving effect of levamisole may also have an influence on the course of allergic diseases, by shifting the Th₂ dominant immunity more toward Th₁‐mediated response. BALB/c mice were sensitized intraperitoneally on days 0, 7, and 15 with ovalbumin (OVA). After the sensitization, they were challenged intranasally with OVA once a day for 6 consecutive days. Levamisole (2.5 mg/kg) was administered orally three times a week during sensitization and challenge. After the last challenge, differential cell counts were performed, and IL‐4 and IFNγ levels were measured in the bronchoalveolar lavage fluids (BALF). Serum total IgE level was determined, and lungs were examined histologically. The present study establishes that mice administered with oral levamisole gave significantly lower IL‐4 levels on sensitization with OVA; however, IFNγ production, eosinophil infiltration, and serum IgE levels remained unaffected. In conclusion, use of levamisole may have important implications in the management of the allergic inflammation.     

Hypersensitivity pneumonitis in athymic nude mice. Additional evidence of T cell dependency.

We previously demonstrated that C57 Black/6 mice develop lung lesions similar to human hypersensitivity pneumonitis (HP) by repeated transnasal administration of Thermoactinomyces vulgaris (Tv) antigen. To elucidate the role of T cells in the development of this disease, Tv antigen (90 micrograms/day) was transnasally administered to athymic nude C57 Black/nu/nu (nu) mice and their littermates (+/nu) three times a week for 3 wk. The nude mice developed minimal lung lesions, whereas their thymus-intact littermates (+/nu) showed changes equivalent to those in C57 Black/6. Changes in local inflammatory cell responses were evaluated by bronchoalveolar lavage, and increases in the numbers of lymphocytes and macrophages were significantly less severe in the nude mice than in the +/nu mice. Interestingly, the increase in polymorphonuclear leukocytes 6 h after the last antigen inoculation was equivalently seen in both groups. When spleen-derived T cells (more than 95% Thy-1.2+) from the sensitized +/nu mice were adoptively transferred to nude mice, the HP-like lesions in the recipients were found after Tv antigen challenge. These results suggest that Thy-1.2+ T cell-mediated immunity was necessary for the development of HP in this murine model.     

Immunohistopathology of murine pulmonary histoplasmosis during normal and hypersensitive conditions.

Pulmonary histoplasmosis was induced in nonimmunized and immunized Balb-C nu/+ mice. The lung tissue burden of H. capsulatum, histopathology, the size of the inflammatory area, and the numbers of total T lymphocytes and subtypes in situ were evaluated serially after challenge. Over 3 days previously immunized mice developed a large lymphocyte/macrophage inflammatory response. This rapidly decreased in the next 2 wk. In contrast, the nonimmunized control mice developed a predominantly polymorphonuclear infiltrate that evolved more slowly over the first week of infection. This initial response was nonspecific but, after the first week, shifted to lymphocytes and granuloma formation. The lymphocyte infiltration in both immunized and nonimmunized mice was predominantly CD4. Previously immunized mice had a rapid decrease in tissue counts of H. capsulatum after Day 3, but nonimmunized mice continued to have increased counts through Day 7 after infection. These studies reproduce in the mouse model a host response similar to acute reinfection histoplasmosis in the human. In this condition an intense cell-mediated inflammatory response is thought to be elicited by fungal antigens and to represent host reaction rather than fungal replication. Our experimental model added new information relevant to the understanding of the pathogenesis of this process.     

致敏小鼠抗原激发后肺局部免疫反应的研究

目的：探讨抗原致敏和激发后肺局部免疫反应的变化。方法：以抗原钥孔嘁血兰素（KLH）经气管内滴注致敏小鼠，2－4周后进行激发，期间分别收集支气管肺泡灌洗液（BALF）和外周血，对肺、肺相关淋巴结（LALN）和脾组织细胞悬液进行培养并收集上清液，以酶联免疫吸附试验（ELISA）测定总IgA、抗KLHIgA及白蛋白。结果：KLH致敏和激发均引起BALF中抗KLHIgA反应。抗原致敏和激发后BALF中抗KLHIgA／白蛋白比率明显高于血清；抗原致敏激发后肺和LALN细胞悬液在体外均可释放抗KLHIgA，而脾细胞悬液仅释放低水平抗KLHIgA。结论：气管内滴注抗原致敏小鼠可诱导肺局部抗原特异IgA反应，抗原激发后反应加强，肺局部积聚的抗KLHIgA并非由血中渗漏而来，而是局部产生的结果，肺和LALN中的淋巴细胞是抗原特异IgA的主要来源。     

不同品系小鼠对卡氏肺孢子虫的易感性及其免疫反应的研究

目的　探讨不同品系小鼠对卡氏肺孢子虫 (P.c)的易感性及其免疫反应。　方法　以接触传播方式使BAL B/ c和 C5 7BL / 6小鼠 (各 15只 )感染 P.c。观察小鼠与传染源接触 4、5、6 wk后肺内虫数、支气管肺泡灌洗液中CD4 + T细胞和 CD8+ T细胞及血清 Ig G水平的变化。　结果　与传染源接触 4 wk,小鼠肺内均可检出 P.c,之后 ,BAL B/ c小鼠虫数继续增高 ,5 wk末达高峰。4 wk时 C5 7BL/ 6小鼠虫数无明显变化 ,5 wk时显著少于 BAL B/ c小鼠。两组小鼠支气管肺泡灌洗液内 CD4 + CD6 2 low T细胞和 CD8+ CD6 2 low T细胞数明显增多 ,血清 Ig G抗体水平显著上升。6 wk小鼠肺内 P.c均转阴。　结论　 BAL B/ c比 C5 7BL / 6小鼠更易感染 P.c。 BAL B/ c和 C5 7BL / 6小鼠感染 P.c后5 wk可产生有效的细胞和体液免疫反应并清除肺内感染的 P.c     

Pulmonary immune responses to Nippostrongylus brasiliensis: isotype-specific antibodies in bronchoalveolar lavage fluids of rats

Larvae of Nippostrongylus brasiliensis have an obligatory migratory phase through the lungs of rats during their development. Since earlier studies have shown that this migration is associated with accumulation of Fc receptor bearing effector cells in the bronchoalveolar spaces, wc have analysed antibody reactivity in bronchoalveolar lavage fluids (BALF) during development of immune responses against N. brasiliensis. The development of parasite specific antibodies in bronchoalveolar spaces was similar to that in the serum, but was of a lower titre. A secondary infection resulted in an anamnestic response. Iso type analysis showed that IgG, IgA and IgM antibodies were present in BALF and they recognized several proteins of the parasite ranging from 16-290 kDa. Immunoblot analysis on two-dimensional electrophoretic separated parasitic proteins identified stage specific differences in the BALF antibody responses. IgG was the predominant class of antibody in BALF and when compared with serum, IgM antibody responses were weak. Thus, infection with N. brasiliensis resulted in the appearance of site-, stage- and isotype-specific antibody responses in the lungs of rats.     

Inflammatory mediators and cellular infiltration of the lungs in a guinea pig model of the late asthmatic reaction

Alterations in cell numbers, vascular permeability, and concentrations of various inflammatory mediators in the lung were measured in a guinea pig model of the late asthmatic reaction. Animals sensitized by inhalation of ovalbumin were challenged with an aerosol of ovalbumin or saline, and bronchoalveolar lavage fluid (BALF) and peripheral blood were collected after periods ranging from 5 min to 72 h. Increased vascular leakage within the lungs was indicated by elevated BALF/plasma albumin ratios at all time points, and was maximal 6 h after challenge. There were increased numbers of eosinophils in BALF by 6 h after challenge and they remained elevated at least until 72 h. A corresponding increase in the proportion of blood leukocytes represented by eosinophils was observed at 6 and 17 h, which suggests that these cells may be drawn to the lung following their release into the circulation, but by 72 h the proportion in blood had returned to normal. A transitory neutrophilia was evident in BALF and blood 6 h after allergen exposure, but there were no allergen-induced changes in BALF numbers of macrophages, lymphocytes, epithelial cells, or mast cells (as assessed by concentrations of cell-associated histamine). beta-Glucuronidase activity was significantly increased in BALF of guinea pigs at 2 h and 17 h following challenge. The degree to which eicosanoids can be recovered in BALF was investigated by instilling a range of tritiated compounds into the lungs of normal guinea pigs at the time of lavage. Ratio high-performance liquid chromatography revealed that there had been little metabolism of the eicosanoids recovered in BALF. However, there was evidence for a rapid removal of these mediators from the lung, a process which will militate against their accurate quantitation in BALF. Histamine, prostaglandin D2, and thromboxane B2 were detected in BALF but did not differ between treatment groups, and levels showed no simple relationship with the other inflammatory changes measured.     

Septic arthritis due to Histoplasma capsulatum in a leukaemic patient.

A case of septic, histoplasmal monoarthritis of the knee in a leukaemic patient is described. Ketoconazole therapy failed to eliminate the infection, but after histoplasmosis was diagnosed prolonged therapy with amphotericin B was curative.     

Production of inflammatory cytokines in ventilator-induced lung injury: a reappraisal

We investigated the production of proinflammatory cytokines by the lung during high mechanical stretch in vivo. To do this, we subjected rats to high-volume (42 ml/kg tidal volume [VT]) ventilation for 2 h. The animals developed severe pulmonary edema and alveolar flooding, with a high protein concentration in bronchoalveolar lavage fluid (BALF). The animals' BALF contained no tumor necrosis factor (TNF)-alpha, negligible amounts of interleukin (IL)-1beta, and less than 300 pg/ml of the chemokine macrophage inflammatory protein (MIP)-2, an amount similar to that found in rats ventilated with 7 ml/kg VT. Systemic cytokine levels were below the detection threshold. Because isolated lungs have been shown to produce high levels of proinflammatory cytokines when ventilated with a similarly high VT for the same duration (Tremblay, et al. J Clin Invest 1997;99:944-952), we reconsidered this specific issue. We ventilated isolated, unperfused rat lungs for 2 h with 7 ml/kg or 42 ml/kg VT, or maintained them in a statically inflated state. Negligible amounts of TNF-alpha were found in the BALF whatever the ventilatory condition applied. The BALF IL-1beta concentration was slightly elevated and higher in lungs ventilated with 42 ml/kg VT than in those ventilated with 7 ml/kg VT or in statically inflated lungs (p < 0.05). The BALF MIP-2 concentration was moderately elevated in all isolated lungs (200 to 300 pg/ml), and was slightly higher (p < 0.05) in lungs ventilated with 42 ml/kg VT. After lipopolysaccharide (LPS) challenge, high levels of TNF-alpha, IL-1beta, and MIP-2 were found in the animals' plasma before the lungs were removed. Negligible amounts of TNF-alpha and IL-1beta were retrieved from the BALF of statically inflated lungs. The concentrations of TNF-alpha and IL-1beta were higher in the BALF of ventilated lungs (p < 0.001). The TNF-alpha level did not differ with the magnitude of VT, whereas the level of IL-1beta was significantly higher in BALF of lungs ventilated with 42 ml/kg VT (p < 0.01). The MIP-2 concentrations were similar for the two ventilatory conditions. These results suggest that ventilation that severely injures lungs does not lead to the release of significant amounts of TNF-alpha or IL-1beta by the lung in the absence of LPS challenge but may increase lung MIP-2 production.     

Levamisole: Might It Be used in Treatment and Prevention of Atopic Diseases?

As an antihelmintic and Th₁-biased immunostimulant, levamisole has been used to restore impaired cell mediated immunity. We sought to explore whether the Th₁ driving effect of levamisole may also have an influence on the course of allergic diseases, by shifting the Th₂ dominant immunity more toward Th₁-mediated response. BALB/c mice were sensitized intraperitoneally on days 0, 7, and 15 with ovalbumin (OVA). After the sensitization, they were challenged intranasally with OVA once a day for 6 consecutive days. Levamisole (2.5 mg/kg) was administered orally three times a week during sensitization and challenge. After the last challenge, differential cell counts were performed, and IL-4 and IFNγ levels were measured in the bronchoalveolar lavage fluids (BALF). Serum total IgE level was determined, and lungs were examined histologically. The present study establishes that mice administered with oral levamisole gave significantly lower IL-4 levels on sensitization with OVA; however, IFNγ production, eosinophil infiltration, and serum IgE levels remained unaffected. In conclusion, use of levamisole may have important implications in the management of the allergic inflammation.     

Inflammatory mediators and cellular infiltration of the lungs in a guinea pig model of the late asthmatic reaction

Alterations in cell numbers, vascular permeability, and concentrations of various inflammatory mediators in the lung were measured in a guinea pig model of the late asthmatic reaction. Animals sensitized by inhalation of ovalbumin were challenged with an aerosol of ovalbumin or saline, and bronchoalveolar lavage fluid (BALF) and peripheral blood were collected after periods ranging from 5 min to 72 h. Increased vascular leakage within the lungs was indicated by elevated BALF/plasma albumin ratios at all time points, and was maximal 6 h after challenge. There were increased numbers of eosinophils in BALF by 6 h after challenge and they remained elevated at least until 72 h. A corresponding increase in the proportion of blood leukocytes represented by eosinophils was observed at 6 and 17 h, which suggests that these cells may be drawn to the lung following their release into the circulation, but by 72 h the proportion in blood had returned to normal. A transitory neutrophilia was evident in BALF and blood 6 h after allergen exposure, but there were no allergen-induced changes in BALF numbers of macrophages, lymphocytes, epithelial cells, or mast cells (as assessed by concentrations of cell-associated histamine).β-Glucuronidase activity was significantly increased in BALF of guinea pigs at 2 h and 17 h following challenge. The degree to which eicosanoids can be recovered in BALF was investigated by instilling a range of tritiated compounds into the lungs of normal guinea pigs at the time of lavage. Ratio high-performance liquid chromatography revealed that there had been little metabolism of the eicosanoids recovered in BALF. However, there was evidence for a rapid removal of these mediators from the lung, a process which will militate against their accurate quantitation in BALF. Histamine, prostaglandin D₂, and thromboxane B₂ were detected in BALF but did not differ between treatment groups, and levels showed no simple relationship with the other inflammatory changes measured.     

鼻腔接种伤寒杆菌Fe-SOD的抗体应答及对鼠伤寒杆菌攻击的免疫保护作用

目的　探讨鼻腔接种伤寒杆菌Fe SOD后血液和粘膜系统的抗体应答及免疫保护作用。方法　用IL - 1作为佐剂 ,将伤寒杆菌Fe SOD经鼻腔接种小鼠 ,检测小鼠血液及肠液中的抗体应答 ,并用鼠伤寒杆菌攻击小鼠 ,观察小鼠的存活情况 ,以确定免疫保护作用。结果　当用IL - 1作为佐剂时 ,经鼻腔接种伤寒杆菌Fe SOD的小鼠血液和肠液中可产生高水平特异性IgG和IgA ;而腹腔注射仅在血液中产生高水平特异性IgG。另外发现经鼻腔接种伤寒杆菌Fe SOD的小鼠在 2LD50 鼠伤寒杆菌攻击后 ,3d和 7d的存活率均明显高于对照组 (P <0 0 5 ) ,且以 5LD50 鼠伤寒杆菌攻击时 ,小鼠 7d的存活率明显高于对照组 (P <0 0 1)。结论　结果说明伤寒杆菌Fe SOD经鼻腔接种后可引起小鼠粘膜系统和血液中的抗体应答 ;对鼠伤寒杆菌的攻击可产生一定的免疫保护作用 ,也进一步说明了Fe SOD是沙门菌的共同保护性抗原。     

Beneficial effects of Galectin-9 on allergen-specific sublingual immunotherapy in a Dermatophagoides farinae-induced mouse model of chronic asthma

Background

Allergen-specific sublingual immunotherapy is a potential disease-modifying treatment for allergic asthma. Galectin-9 (Gal-9), a β-galactoside-binding protein with various biologic effects, acts as an immunomodulator in excessive immunologic reactions by expanding regulatory T cells (Treg) and enhancing transforming growth factor (TGF)-β signaling. We investigated the efficacy of sublingually administered Gal-9 as an adjuvant to a specific allergen in a Dermatophagoides farinae (Df)-induced mouse model of chronic asthma.

Specific bronchoalveolar lavage IgA antibody in patients with summer-type hypersensitivity pneumonitis induced by Trichosporon cutaneum

Patients with summer-type hypersensitivity pneumonitis induced by Trichosporon cutaneum were studied with respect to specific IgG, IgA, and secretory IgA (S-IgA) antibody activities to T. cutaneum in serum and bronchoalveolar lavage fluid (BALF). A strain of T. cutaneum was isolated from 1 patient's pillow. All serum samples from the family members (2 patients and 2 asymptomatic) contained IgG antibody activity to T. cutaneum, and the titers showed no difference between the patients and asymptomatic family members. On the other hand, IgA and S-IgA antibody activities in serum and BALF were markedly increased only in the patients, and the titers were well correlated with the clinical course. The BALF/serum ratio of specific antibody activity was markedly elevated in IgA and S-IgA antibody activities in striking contrast to that in IgG, suggesting an immune reaction of the respiratory tract. The bronchial challenge test with T. cutaneum antigen was positive in the patients, but not in an asymptomatic family member. These results indicate that measurement of IgA and S-IgA antibody activities in serum and BALF is useful for diagnosis and evaluation of disease activity in summer-type hypersensitivity pneumonitis.     

Peripheral blood smear findings in a kidney transplant recipient with disseminated histoplasmosis and elevated Aspergillus galactomannan

We report a case of disseminated histoplasmosis in a renal transplant recipient who presented with a nodular pulmonary lesion and elevated serum and bronchoalveolar lavage (BAL) Aspergillus galatomannan. This almost led to an erroneous diagnosis of invasive aspergillosis since the donor respiratory tract was known to be colonized with Aspergillus terreus. However, distinctive intracelluar Histoplasma yeasts on peripheral blood smear led to early diagnosis and appropriate treatment. The cross‐reactivity between Aspergillus galactomannan and Histoplasma antigen is discussed further.