Arginase inhibitor reduces fungal dissemination in murine pulmonary cryptococcosis by promoting anti-cryptococcal immunity.

Elevation of arginase enzyme activity in the lung contributes to the pathogenesis of various chronic inflammatory diseases and infections. Inhibition of arginase expression and activity is able to alleviate those effects. Here, we investigated the immunomodulatory effect of arginase inhibitor in C. neoformans infection. In the pulmonary cryptococcosis model that was shown to recapitulate human infection, we found arginase expression was excessively induced in the lung during the late stage of infection. To inhibit the activity of arginase, we administered a specific arginase inhibitor, nor-NOHA, during C. neoformans infection. Inhibition of arginase reduced eosinophil infiltration and level of IL-13 secretion in the lungs. Whole lung transcriptome RNA-sequencing analysis revealed that treatment with nor-NOHA resulted in shifting the Th2-type gene expression patterns induced by C. neoformans infection to the Th1-type immune profile, with higher expression of cytokines Ifng, Il6, Tnfa, Csf3, chemokines Cxcl9 and Cxcl10 and transcription factor Stat1. More importantly, mice treated with arginase inhibitor had more infiltrating brain leukocytes and enhanced gene expression of Th1-associated cytokines and chemokines that are known to be essential for protection against C. neoformans infection. Inhibition of arginase dramatically attenuated spleen and brain infection, with improved survival. Taken together, these studies demonstrated that inhibiting arginase activity induced by C. neoformans infection can modulate host immune response by enhancing protective type-1 immune response during C. neoformans infection. The inhibition of arginase activity could be an immunomodulatory target to enhance protective anti-cryptococcal immune responses.

Single-Cell Transcriptional Heterogeneity of Neutrophils During Acute Pulmonary Cryptococcus neoformans Infection.

Neutrophils are critical as the first-line defense against fungal pathogens. Yet, previous studies indicate that neutrophil function is complex during Cryptococcus neoformans (Cn) infection. To better understand the role of neutrophils in acute pulmonary cryptococcosis, we analyzed neutrophil heterogeneity by single-cell transcriptional analysis of immune cells in the lung of Cn-infected mice from a published dataset. We identified neutrophils by reference-based annotation and identified two distinct neutrophil subsets generated during acute Cn infection: A subset with an oxidative stress signature (Ox-PMN) and another with enhanced cytokine gene expression (Cyt-PMN). Based on gene regulatory network and ligand-receptor analysis, we hypothesize that Ox-PMNs interact with the fungus and generate ROS, while Cyt-PMNs are longer-lived neutrophils that indirectly respond to Cn-derived ligands and cytokines to modulate cell-cell communication with dendritic cells and alveolar macrophages. Based on the data, we hypothesized that, during in vivo fungal infection, there is a division of labor in which each activated neutrophil becomes either Ox-PMN or Cyt-PMN.

AhR Ligands Modulate the Differentiation of Innate Lymphoid Cells and T Helper Cell Subsets That Control the Severity of a Pulmonary Fungal Infection.

In agreement with other fungal infections, immunoprotection in pulmonary paracoccidioidomycosis (PCM) is mediated by Th1/Th17 cells whereas disease progression by prevalent Th2/Th9 immunity. Treg cells play a dual role, suppressing immunity but also controlling excessive tissue inflammation. Our recent studies have demonstrated that the enzyme indoleamine 2,3 dioxygenase (IDO) and the transcription factor aryl hydrocarbon receptor (AhR) play an important role in the immunoregulation of PCM. To further evaluate the immunomodulatory activity of AhR in this fungal infection, Paracoccidioides brasiliensis infected mice were treated with two different AhR agonists, L-Kynurenin (L-Kyn) or 6-formylindole [3,2-b] carbazole (FICZ), and one AhR specific antagonist (CH223191). The disease severity and immune response of treated and untreated mice were assessed 96 hours and 2 weeks after infection. Some similar effects on host response were shared by FICZ and L-Kyn, such as the reduced fungal loads, decreased numbers of CD11c+ lung myeloid cells expressing activation markers (IA, CD40, CD80, CD86), and early increased expression of IDO and AhR. In contrast, the AhR antagonist CH223191 induced increased fungal loads, increased number of pulmonary CD11c+ leukocytes expressing activation markers, and a reduction in AhR and IDO production. While FICZ treatment promoted large increases in ILC3, L-Kyn and CH223191 significantly reduced this cell population. Each of these AhR ligands induced a characteristic adaptive immunity. The large expansion of FICZ-induced myeloid, lymphoid, and plasmacytoid dendritic cells (DCs) led to the increased expansion of all CD4+ T cell subpopulations (Th1, Th2, Th17, Th22, and Treg), but with a clear predominance of Th17 and Th22 subsets. On the other hand, L-Kyn, that preferentially activated plasmacytoid DCs, reduced Th1/Th22 development but caused a robust expansion of Treg cells. The AhR antagonist CH223191 induced a preferential expansion of myeloid DCs, reduced the number of Th1, Th22, and Treg cells, but increased Th17 differentiation. In conclusion, the present study showed that the pathogen loads and the immune response in pulmonary PCM can be modulated by AhR ligands. However, further studies are needed to define the possible use of these compounds as adjuvant therapy for this fungal infection.

Effect of patient immunodeficiencies on the diagnostic performance of serological assays to detect Aspergillus-specific antibodies in chronic pulmonary aspergillosis.

BACKGROUND: Prevalence of chronic pulmonary aspergillosis (CPA) is ~3 million patients worldwide, and detection of Aspergillus-specific antibody is a critical diagnostic component. Some patients with CPA have subtle immune deficits possibly contributing to poor Aspergillus antibody production and false negative results. MATERIALS/METHODS: We analyzed patient data from 167 cases of clinically confirmed CPA previously evaluated by ImmunoCAP Aspergillus-specific IgG EIA, Bordier ELISA and LDBio Aspergillus IgG/IgM ICT lateral flow assay, to identify deficiencies in: mannose binding lectin (MBL), IgG, IgA, IgM, IFN gamma, IL12 or IL17 production, and/or low cell marker counts (CD4, CD19, CD56). We defined patients as 'sero-negative' if ImmunoCAP Aspergillus IgG was consistently and repeatedly negative (<40 mg A/L). 'Sero-positive' was defined as all other CPA cases. RESULTS: We found the rate of false negatives by ImmunoCAP Aspergillus IgG EIA (n = 23) to be more prevalent in patients with immunodeficiency markers, especially multiple defects. MBL deficiency combined with low CD19 cells (p < 0.001), pneumococcal antibody levels (p = 0.043), IgM (p = 0.047) or three combined (p = 0.001-0.018) or all four together (p = 0.018) were significant. The performance LDBio Aspergillus IgG/IgM ICT appears to be relatively unaffected by immunodeficiency (92.7% of ImmunoCap sero-negatives were positive). The Bordier assay performed significantly better than the ImmunoCAP assay (P = 0.0016) for sero-negative CPA cases. CONCLUSIONS: In select cases of CPA, ImmunoCAP EIA yields a false negative result, making serological diagnosis difficult. ImmunoCAP false negatives are more prevalent in patients with multiple immunological defects, who may still be positive with the LDBio Aspergillus ICT or Bordier EIA.

Assessment of the pulmonary adaptive immune response to Cladosporium cladosporioides infection using an experimental mouse model.

Cladosporium cladosporioides causes asthma and superficial and deep infections, mostly in immunodeficient individuals and animals. This study aimed to investigate whether C. cladosporioides spores can enter the lungs through pulmonary circulation and influence pulmonary immune response. We intravenously injected mice with C. cladosporioides spore suspension and conducted several assays on the lungs. Pulmonary hemorrhage symptoms and congestion were most severe on days 1, 2, and 3 post-inoculation (PI). Extensive inflammatory cell infiltration occurred throughout the period of infection. More spores and hyphae colonizing the lungs were detected on days 1, 2, and 3 PI, and fewer spores and hyphae were observed within 21 d of infection. Numerous macrophages, dendritic cells, and neutrophils were observed on day 5 PI, along with upregulation of CD54, an intercellular adhesion molecule. Th1 and Th2 cells increased after infection; specifically, Th2 cells increased considerably on day 5 PI. These results suggest that days 2 and 5 PI represent the inflammatory peak in the lungs and that the Th2 and Th1 signaling pathways are potentially involved in pulmonary immune responses. In conclusion, the further adaptive immune responses played important roles in establishing effective pulmonary immunity against C. cladosporioides systemic infections based on innate immune responses.

Diagnostic Value of Flow Cytometry in Kidney Transplant Recipients With Active Pulmonary Tuberculosis.

OBJECTIVES: Long-term use of immunosuppressant drugs in kidney transplant recipients leads to immunosuppression. When active pulmonary tuberculosis infection occurs, lymphocyte proliferation and function are impaired, and the clinical symptoms of patients are not typical, which often leads to delay in diagnosis. MATERIALS AND METHODS: We collected and analyzed the peripheral blood lymphocytes of hospitalized patients with active pulmonary tuberculosis and other types of pulmonary infection after kidney transplant within 2 years. The proportion and absolute values of lymphocytes were obtained by a flow cytometer. RESULTS: There were significant differences in the proportion of CD8+ subsets between active pulmonary tuberculosis and bacterial pneumonia in kidney transplant recipients. If the proportion of CD8+ subsets in peripheral blood is over 33.27%, then the active pulmonary tuberculosis diagnosis sensitivity is higher than 88.9% and specificity is higher than 83.3%. CONCLUSIONS: Analysis of peripheral lymphocyte subsets is helpful in the early diagnosis of kidney transplant recipients with active pulmonary tuberculosis. It should be added into routine examinations of kidney transplant recipients who have an ambiguous diagnosis between active pulmonary tuberculosis and bacterial pneumonia.

The airway fungal microbiome in asthma.

BACKGROUND: Fungal involvement in asthma is associated with severe disease. The full spectrum of fungal species in asthma is not well described and is derived largely from insensitive culture techniques. OBJECTIVES: To use high-throughput sequencing to describe the airway mycobiota in asthmatics with and without fungal sensitization and healthy controls; to compare samples representing different airway compartments; to determine whether the mycobiota was influenced by the fungal composition of outdoor air; and to compare findings with clinically relevant outcomes. METHODS: We amplified the internal transcribed spacer region 2 of the nuclear ribosomal operon to identify the fungal species present. Ninety-seven subjects were recruited and provided sputum (83 asthmatics; 14 healthy subjects), with 29 also undergoing a bronchoscopy. A subset of airway samples were compared with matched outdoor air and mouthwash samples. RESULTS: Two hundred and six taxa at the species level were identified in sputum, most at low relative abundance. Aspergillus fumigatus, Candida albicans and Mycosphaerella tassiana had the highest relative abundances and were the most prevalent species across all subjects. The airway mycobiota consisted of a complex community with high diversity between individuals. Notable shifts in the balance of fungi detected in the lung were associated with asthma status, asthma duration and biomarkers of inflammation. Aspergillus tubingensis, a member of the Aspergillus niger species complex, was most prevalent from bronchoscopic protected brush samples and significantly associated with a low sputum neutrophilia. Cryptococcus pseudolongus, from the Cryptococcus humicola species complex, was more abundant from bronchoscopy samples than sputum, and differentially more abundant in asthma than health. CONCLUSIONS AND CLINICAL RELEVANCE: The airway mycobiota was dominated by a relatively small number of species, but was distinct from the oropharyngeal mycobiota and air samples. Members of the A. niger and C. humicola species complexes may play unexpected roles in the pathogenesis of asthma.

Chronic ethanol consumption compromises neutrophil function in acute pulmonary Aspergillus fumigatus infection.

Chronic ethanol consumption is a leading cause of mortality worldwide, with higher risks to develop pulmonary infections, including Aspergillus infections. Mechanisms underlying increased susceptibility to infections are poorly understood. Chronic ethanol consumption induced increased mortality rates, higher Aspergillus fumigatus burden and reduced neutrophil recruitment into the airways. Intravital microscopy showed decrease in leukocyte adhesion and rolling after ethanol consumption. Moreover, downregulated neutrophil activation and increased levels of serum CXCL1 in ethanol-fed mice induced internalization of CXCR2 receptor in circulating neutrophils. Bone marrow-derived neutrophils from ethanol-fed mice showed lower fungal clearance and defective reactive oxygen species production. Taken together, results showed that ethanol affects activation, recruitment, phagocytosis and killing functions of neutrophils, causing susceptibility to pulmonary A. fumigatus infection. This study establishes a new paradigm in innate immune response in chronic ethanol consumers.

Alcoholism is a chronic disease that has many damaging effects on the body. Over long periods, excessive alcohol intake weakens the immune system, putting consumers at increased risk of getting lung infections such as pneumonia. Some forms of pneumonia can be caused by the fungus Aspergillus fumigatus. This microbe does not tend to be a problem for healthy individuals, but it can be fatal for those with impaired immune systems. Here, Malacco et al. wanted to find out why excessive alcohol consumers are more prone to pneumonia. To test this, the researchers used two groups of mice that were either fed plain water or water containing ethanol. After 12 weeks, both groups were infected with Aspergillus fumigatus. The results showed that alcohol-fed mice were more susceptible to the infection caused by strong inflammation of the lungs. Normally, the immune system confronts a lung infection by activating a group of defense cells called neutrophils, which travel through the blood system to the infection site. Once in the right spot, neutrophils get to work by releasing toxins that kill the fungus. Malacco et al. discovered that after chronic alcohol consumption, neutrophils were less reactive to inflammatory signals and less likely to reach the lungs. They were also less effective in dealing with the infection. Neutrophil released fewer toxins and were thus less able to kill the microbial cells. These findings demonstrate for the first time how alcohol can affect immune cells during infection and pave the way for new possibilities to prevent fatal lung infections in excessive alcohol consumers. A next step would be to identify how alcohol acts on other processes in the body and to find a way to modulate or even revert the changes it causes.

Comparison of cryptococcal meningitis in HIV-negative patients with and without lung infections.

OBJECTIVE: To investigate the clinical features and outcomes of cryptococcal meningitis (CM) in HIV-negative patients with and without lung infections. METHODS: We retrospectively reviewed the medical records of HIV-negative patients with CM admitted to two university hospitals in Southwest China over the past 5 years. RESULTS: Seventy-one patients were included, of whom 35 (49.3%) had lung disease. Compared with patients without lung infection, CM patients with lung infection tended to be male and younger (≤30 years), experienced more fever, less vomiting and fewer central nervous system symptoms; more often had low white blood cell (WBC) counts (<20 × 106/L), and fewer often had ethmoid sinusitis, maxillary sinusitis, paranasal sinusitis, and otitis media. Cryptococcus neoformans isolates from these patients were sensitive to itraconazole, voriconazole, fluconazole, and amphotericin B but resistant to flucytosine. CM patients with lung infection had higher mortality at discharge compared with patients without lung infection (8.6% vs. 0%). Multivariable analyses showed that a WBC count <20 × 106/L was significantly associated with poor treatment outcome (odds ratio 0.01, 95% confidence interval 0-0.83). CONCLUSION: HIV-negative CM patients with lung infections tended to be male and younger. Fever, fewer central nervous system symptoms, and WBC counts <20 × 106/L were characteristic of this patient group.

Clinicopathological features of isolated pulmonary cryptococcosis in HIV-negative patients.

OBJECTIVE: To analyse the clinicopathological features of isolated pulmonary cryptococcosis in human immunodeficiency virus (HIV)-negative patients. METHODS: This retrospective study analysed the following data from HIV-negative patients diagnosed with pulmonary cryptococcosis: demographics, underlying diseases, clinical manifestations on admission, laboratory tests, imaging data, results of histopathology, treatment options and outcomes. Sputum samples from all patients were collected and assessed for the presence of yeast or fungi. Cryptococcal antigen testing was performed for some patients. Histopathological analysis was also undertaken for some samples of lung tissue. RESULTS: The study analysed 37 patients (22 males). Thirteen (35.14%) patients were asymptomatic, 24 (64.86%) were symptomatic and 17 (45.95%) patients had no underlying disease. Out of 25 tested patients, 23 (92.00%) tested positive on the serum cryptococcal capsular polysaccharide antigen test. During 6 to 24 months of follow-up, all 37 patients that were either treated with or without antifungal therapy alone or combined with surgical resection showed complete recovery. One patient made a full recovery without any treatment. CONCLUSION: Early identification of pulmonary cryptococcosis in HIV-negative patients and timely detection of cryptococcal antigens in serum or respiratory specimens may help to improve diagnosis, prognosis and treatment of the disease.

Rapid and precise diagnosis of T. marneffei pulmonary infection in a HIV-negative patient with autosomal-dominant STAT3 mutation: a case report.

BACKGROUND: Talaromyces marneffei, also named Penicillium marneffei, is an opportunistic pathogen that can cause systemic or limited infection in human beings. This infection is especially common in human immunodeficiency virus (HIV)-infected hosts; however, it has also been recently reported in HIV-negative hosts. Here, we report a very rarely seen case of T. marneffei pulmonary infection in a non-HIV-infected patient with signal transducer and activator of transcription 3 (STAT3) mutation. CASE PRESENTATION: A 34-year-old woman was admitted to our hospital for uncontrollable nonproductive cough and dyspnea with exercise. She had been immunocompromised since infancy. Computerized tomography scan showed multiple ground glass opacities with multiple bullae in both lungs. Next generation sequencing (NGS) of the bronchoalveolar lavage fluid identified T. marneffei nucleotide sequences. Culture of bronchoscopy specimens further verified the results. The patient was HIV negative, and blood gene detection indicated STAT3 mutation. To date, following the application of itraconazole, the patient has recovered satisfactorily. CONCLUSION: In clinical practice, T. marneffei infection among HIV-negative individuals is relatively rare, and we found that patients who are congenitally immunocompromised due to STAT3 mutation may be potential hosts. Early diagnosis and timely treatment are expected to improve the prognosis of T. marneffei infection. NGS is a powerful technique that may play an important role in this progress. The reviews of this paper are available via the supplemental material section.

Cryptococcus neoformans Evades Pulmonary Immunity by Modulating Xylose Precursor Transport.

Cryptococcus neoformans is a fungal pathogen that kills almost 200,000 people each year and is distinguished by abundant and unique surface glycan structures that are rich in xylose. A mutant strain of C. neoformans that cannot transport xylose precursors into the secretory compartment is severely attenuated in virulence in mice yet surprisingly is not cleared. We found that this strain failed to induce the nonprotective T helper cell type 2 (Th2) responses characteristic of wild-type infection, instead promoting sustained interleukin 12p40 (IL-12p40) induction and increased IL-17A (IL-17) production. It also stimulated dendritic cells to release high levels of proinflammatory cytokines, a behavior we linked to xylose expression. We further discovered that inducible bronchus-associated lymphoid tissue (iBALT) forms in response to infection with either wild-type cryptococci or the mutant strain with reduced surface xylose; although iBALT formation is slowed in the latter case, the tissue is better organized. Finally, our temporal studies suggest that lymphoid structures in the lung restrict the spread of mutant fungi for at least 18 weeks after infection, which is in contrast to ineffective control of the pathogen after infection with wild-type cells. These studies demonstrate the role of xylose in modulation of host response to a fungal pathogen and show that cryptococcal infection triggers iBALT formation.

Utility of bronchoscopy in immunocompromised paediatric patients: Systematic review.

PURPOSE: The objective of this study was to describe the diagnostic yield and safety of bronchoalveolar lavage (BAL) in the evaluation of pulmonary lesions in immunocompromised children. METHODS: We conducted a systematic review of literature published during the past 20 years, searching Medline, Medline EPub, EMBASE, and Scopus. Studies included involved paediatric patients (<18 years) on treatment for an oncological diagnosis or other immune compromise who underwent BAL for evaluation of pulmonary lesions. Only English language publications were included. RESULTS: In all, 272 studies were screened and 19 included. All were observational studies with moderate (11/19) or serious (8/19) risk of bias. BAL yielded a potential pathogen in 43% of cases (496/1156). Two papers reported improved diagnostic yield with early BAL (less than 3 days of presentation). A change in patient management after BAL was reported in 53% of cases (275/519). Adverse events were reported in 19% of cases following BAL (193/993) but were generally mild with no procedure-related mortality reported. CONCLUSION: BAL appears to be useful for evaluation of pulmonary lesions in immunocompromised children with generally acceptable safety, though included studies had at least moderate risk of bias. Future prospective studies may provide more definitive estimates of benefit, timing and risk of BAL in this population.

Group 2 Innate Lymphoid Cells (ILC2) Suppress Beneficial Type 1 Immune Responses During Pulmonary Cryptococcosis.

Cryptococcus neoformans is an opportunistic fungal pathogen preferentially causing disease in immunocompromised individuals such as organ-transplant-recipients, patients receiving immunosuppressive medications or, in particular, individuals suffering from HIV infection. Numerous studies clearly indicated that the control of C. neoformans infections is strongly dependent on a prototypic type 1 immune response and classical macrophage activation, whereas type 2-biased immunity and alternative activation of macrophages has been rather implicated in disease progression and detrimental outcomes. However, little is known about regulatory pathways modulating and balancing immune responses during early phases of pulmonary cryptococcosis. Here, we analyzed the role of group 2 innate lymphoid cells (ILC2s) for the control of C. neoformans infection. Using an intranasal infection model with a highly virulent C. neoformans strain, we found that ILC2 numbers were strongly increased in C. neoformans-infected lungs along with induction of a type 2 response. Mice lacking ILC2s due to conditional deficiency of the transcription factor RAR-related orphan receptor alpha (Rora) displayed a massive downregulation of features of type 2 immunity as reflected by reduced levels of the type 2 signature cytokines IL-4, IL-5, and IL-13 at 14 days post-infection. Moreover, ILC2 deficiency was accompanied with increased type 1 immunity and classical macrophage activation, while the pulmonary numbers of eosinophils and alternatively activated macrophages were reduced in these mice. Importantly, this shift in pulmonary macrophage polarization in ILC2-deficient mice correlated with improved fungal control and prolonged survival of infected mice. Conversely, adoptive transfer of ILC2s was associated with a type 2 bias associated with less efficient anti-fungal immunity in lungs of recipient mice. Collectively, our date indicate a non-redundant role of ILC2 in orchestrating myeloid anti-cryptococcal immune responses toward a disease exacerbating phenotype.

Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation.

Pulmonary mucormycosis (PM) is an uncommon fungal infection most often seen in immunocompromised patients. The fungus grows on decaying food, soil, and animal excrement. Patients usually become infected by inhalation of spores. The most common risk factors include diabetes mellitus, hematologic malignancy, and solid organ or stem cell transplant. PM can have a nonspecific appearance at imaging. For example, early imaging may show peribronchial ground-glass opacity. Later, the disease progresses to consolidation, nodules, or masses. Because patients are usually immunocompromised, the differential diagnosis often includes invasive pulmonary aspergillosis (IPA). Various radiologic findings suggestive of PM have been identified to help differentiate it from IPA. For example, the reverse halo sign is more closely associated with PM than with IPA. The reverse halo sign is an area of ground-glass opacity surrounded by a rim of consolidation. In addition, the presence of pleural effusions and more than 10 nodules is more suggestive of PM than it is of IPA. PM can progress rapidly in neutropenic patients. Identification of the hyphae in tissue by using endobronchial or percutaneous sampling can allow differentiation from IPA and help confirm the diagnosis of mucormycosis. Because of the high mortality rate associated with PM, early identification of the disease is critical for an improved likelihood of survival. A multimodality treatment approach with antifungal agents and surgical débridement has been shown to improve outcomes. The authors review the risk factors for PM, describe its imaging appearance and disease process, and describe the treatment of the disease. ©RSNA, 2020.

Pulmonary infection due to Acrophialophora fusispora in a patient with underlying mixed connective tissue disease and chronic pulmonary aspergillosis: A case report and review of literature.

Acrophialophora fusispora is a soil-borne fungus rarely implicated in human infections. Here, we report a case of pulmonary infection due to A. fusispora in a 59-year-old male who presented with productive cough and gradually progressive dyspnoea for 20 days. He had a past history of pulmonary tuberculosis and was a known case of chronic obstructive pulmonary disease for past five years. He was diagnosed with mixed connective tissue disease and had been receiving oral azathioprine and prednisolone for three months. CECT thorax revealed an aspergilloma and serum Aspergillus fumigatus-specific IgG levels were raised, suggestive of chronic pulmonary aspergillosis. He was also tested positive for influenza A (H1N1) and received treatment with oral oseltamivir without any clinical benefit. Culture of sputum and bronchoalveolar lavage fluid showed growth of a fungus which was identified as Acrophialophora fusispora based on characteristic microscopic morphology and internal transcribed spacer sequencing of the ribosomal DNA. Antifungal susceptibility testing for six antifungal drugs showed itraconazole to have the most potent in vitro activity (MIC=0.25µg/mL) against A. fusispora in comparison to the other drugs tested. Treatment with itraconazole capsule 200mg twice daily was initiated and favourable clinical response was observed after 10 days of therapy. Follow-up visit after three months showed marked clinical and radiological improvement. A. fusispora is an emerging opportunistic fungus capable of causing invasive infections in immunocompromised hosts. Lack of knowledge about this fungus and confusion with morphologically similar opportunistic fungi have led to its misidentification and hence its prevalence remains largely underestimated. Accurate identification is crucial as it can help initiate early effective antifungal therapy and improve patient outcomes. To our knowledge, this is the first case of pulmonary infection due to A. fusispora reported from India.

Pulmonary Cryptococcosis: comparison of Cryptococcal antigen detection and radiography in Immunocompetent and Immunocompromised patients.

BACKGROUND: We compared the cryptococcal antigen detection and imaging findings between immunocompetent and immunocompromised patients in whom pulmonary cryptococcosis had been diagnosed. The aim of our study was to determine whether the patient's immune status and radiography affect the detection of cryptococcal antigen. METHODS: According to whether they took immunosuppressive drugs or not, seventy and eight adult patients with pulmonary cryptococcosis were divided into two groups: the immunocompetent group and the immunocompromised group. According to the detection of CrAg, each group was divided into the CrAg+ group and the CrAg- group. Then, clinical records, laboratory examinations and computed tomography findings were collected and analyzed. RESULTS: No difference was found in baseline characteristics, clinical symptoms, and laboratory investigations. By comparing CrAg detection in these two groups, it was found that the number of CrAg+ cases in the immunocompetent group was more than that in the immunocompromised group. And in the immunocompetent group, diffuse lesions were more common in CrAg+ group and limited lesions were more frequently observed in CrAg- group. CONCLUSIONS: The patient's immune status and radiography would affect the detection of cryptococcal antigen. And serum CrAg could be a useful tool for the diagnosis of pulmonary cryptococcosis in immunocompetent patients with extensive lung involvement.

CARD9 Is Required for Classical Macrophage Activation and the Induction of Protective Immunity against Pulmonary Cryptococcosis.

Caspase recruitment domain-containing protein 9 (CARD9) is a critical adaptor molecule triggered by the interaction of C-type lectin receptors (CLRs) with carbohydrate motifs found in fungi. Consequently, clinical and animal studies indicate that CARD9 is an important regulator of protective immunity against fungal pathogens. Previous studies suggest that CARD9 is important for the induction of protection against Cryptococcus neoformans, an opportunistic fungal pathogen that causes life-threatening infections of the central nervous system in immunocompromised patients. However, the effect of CARD9 deficiency on the induction of protective immune responses against C. neoformans is unknown. Immunization with a C. neoformans mutant that overexpresses the transcription factor zinc finger 2, denoted LW10, results in protection against an otherwise lethal challenge with wild-type (WT) C. neoformans Our results showed that CARD9 is essential for the induction of vaccine-mediated immunity against C. neoformans infection. We observed significant decreases in interleukin-17 (IL-17) production and significant increases in Th2-type cytokine (IL-4, IL-5, and IL-13) production in CARD9-deficient mice after inoculation with strain LW10. While leukocyte infiltration to the lungs of CARD9-deficient mice was similar in LW10 and WT C. neoformans-infected mice, macrophages derived from CARD9-deficient mice inherently skewed toward an M2 activation phenotype, were unable to contain the growth of LW10, and failed to produce nitric oxide in response to infection with LW10 or stimulation with lipopolysaccharide. These results suggest that CARD9-mediated signaling is required for M1 macrophage activation and fungicidal activity necessary for the induction of vaccine-mediated immunity against C. neoformansIMPORTANCECryptococcus neoformans is a fungal pathogen that is found throughout the environment and can cause life-threatening infections of the lung and central nervous system in severely immunocompromised individuals. Caspase recruitment domain-containing protein 9 (CARD9) is a critical molecule that is activated after interactions of C-type lectin receptors (CLRs) found on the surfaces of specific immune cells, with carbohydrate structures associated with fungi. Patients with defects in CARD9 are significantly more susceptible to a multitude of fungal infections. C. neoformans contains several carbohydrate structures that interact with CLRs on immune cells and activate CARD9. Consequently, these studies evaluated the necessity of CARD9 for the induction of protective immunity against C. neoformans infection. These results are important, as they advance our understanding of cryptococcal pathogenesis and host factors necessary for the induction of protective immunity against C. neoformans.