Deciphering lung granulomas in HIV & TB co-infection: unveiling macrophages aggregation with IL6R/STAT3 activation.

Tuberculosis (TB) remains a leading cause of mortality among individuals coinfected with HIV, characterized by progressive pulmonary inflammation. Despite TB's hallmark being focal granulomatous lung lesions, our understanding of the histopathological features and regulation of inflammation in HIV & TB coinfection remains incomplete. In this study, we aimed to elucidate these histopathological features through an immunohistochemistry analysis of HIV & TB co-infected and TB patients, revealing marked differences. Notably, HIV & TB granulomas exhibited aggregation of CD68 + macrophage (Mφ), while TB lesions predominantly featured aggregation of CD20+ B cells, highlighting distinct immune responses in coinfection. Spatial transcriptome profiling further elucidated CD68+ Mφ aggregation in HIV & TB, accompanied by activation of IL6 pathway, potentially exacerbating inflammation. Through multiplex immunostaining, we validated two granuloma types in HIV & TB versus three in TB, distinguished by cell architecture. Remarkably, in the two types of HIV & TB granulomas, CD68 + Mφ highly co-expressed IL6R/pSTAT3, contrasting TB granulomas' high IFNGRA/SOCS3 expression, indicating different signaling pathways at play. Thus, activation of IL6 pathway may intensify inflammation in HIV & TB-lungs, while SOCS3-enriched immune microenvironment suppresses IL6-induced over-inflammation in TB. These findings provide crucial insights into HIV & TB granuloma formation, shedding light on potential therapeutic targets, particularly for granulomatous pulmonary under HIV & TB co-infection. Our study emphasizes the importance of a comprehensive understanding of the immunopathogenesis of HIV & TB coinfection and suggests potential avenues for targeting IL6 signaling with SOCS3 activators or anti-IL6R agents to mitigate lung inflammation in HIV & TB coinfected individuals.

Unpaired virtual histological staining using prior-guided generative adversarial networks.

Fibrosis is an inevitable stage in the development of chronic liver disease and has an irreplaceable role in characterizing the degree of progression of chronic liver disease. Histopathological diagnosis is the gold standard for the interpretation of fibrosis parameters. Conventional hematoxylin-eosin (H&E) staining can only reflect the gross structure of the tissue and the distribution of hepatocytes, while Masson trichrome can highlight specific types of collagen fiber structure, thus providing the necessary structural information for fibrosis scoring. However, the expensive costs of time, economy, and patient specimens as well as the non-uniform preparation and staining process make the conversion of existing H&E staining into virtual Masson trichrome staining a solution for fibrosis evaluation. Existing translation approaches fail to extract fiber features accurately enough, and the decoder of staining is unable to converge due to the inconsistent color of physical staining. In this work, we propose a prior-guided generative adversarial network, based on unpaired data for effective Masson trichrome stained image generation from the corresponding H&E stained image. Conducted on a small training set, our method takes full advantage of prior knowledge to set up better constraints on both the encoder and the decoder. Experiments indicate the superior performance of our method that surpasses the previous approaches. For various liver diseases, our results demonstrate a high correlation between the staging of real and virtual stains (ρ=0.82; 95% CI: 0.73-0.89). In addition, our finetuning strategy is able to standardize the staining color and release the memory and computational burden, which can be employed in clinical assessment.

Spike-mediated ACE2 down-regulation was involved in the pathogenesis of SARS-CoV-2 infection.

The ongoing global pandemic of Coronavirus disease 2019 (COVID-19) poses a serious threat to human health, with patients reportedly suffering from thrombus, vascular injury and coagulation in addition to acute and diffuse lung injury and respiratory diseases. Angiotensin converting enzyme 2 (ACE2) as the receptor for SARS-CoV-2 entry, is also an important regulator of renin-angiotensin system (RAS) homeostasis, which plays an unsettled role in the pathogenesis of COVID-19. Here, we demonstrated that SARS-CoV-2 Spike protein activated intracellular signals to degrade ACE2 mRNA. The decrease of ACE2 and higher level of angiotensin (Ang) II were verified in COVID-19 patients. High dose of Ang II induced pulmonary artery endothelial cell death in vitro, which was also observed in the lung of COVID-19 patients. Our finding indicates that the downregulation of ACE2 potentially links COVID-19 to the imbalance of RAS.

SARS-CoV-2 promotes RIPK1 activation to facilitate viral propagation.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the ongoing global pandemic that poses substantial challenges to public health worldwide. A subset of COVID-19 patients experience systemic inflammatory response, known as cytokine storm, which may lead to death. Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is an important mediator of inflammation and cell death. Here, we examined the interaction of RIPK1-mediated innate immunity with SARS-CoV-2 infection. We found evidence of RIPK1 activation in human COVID-19 lung pathological samples, and cultured human lung organoids and ACE2 transgenic mice infected by SARS-CoV-2. Inhibition of RIPK1 using multiple small-molecule inhibitors reduced the viral load of SARS-CoV-2 in human lung organoids. Furthermore, therapeutic dosing of the RIPK1 inhibitor Nec-1s reduced mortality and lung viral load, and blocked the CNS manifestation of SARS-CoV-2 in ACE2 transgenic mice. Mechanistically, we found that the RNA-dependent RNA polymerase of SARS-CoV-2, NSP12, a highly conserved central component of coronaviral replication and transcription machinery, promoted the activation of RIPK1. Furthermore, NSP12 323L variant, encoded by the SARS-CoV-2 C14408T variant first detected in Lombardy, Italy, that carries a Pro323Leu amino acid substitution in NSP12, showed increased ability to activate RIPK1. Inhibition of RIPK1 downregulated the transcriptional induction of proinflammatory cytokines and host factors including ACE2 and EGFR that promote viral entry into cells. Our results suggest that SARS-CoV-2 may have an unexpected and unusual ability to hijack the RIPK1-mediated host defense response to promote its own propagation and that inhibition of RIPK1 may provide a therapeutic option for the treatment of COVID-19.

COVID-19: Abnormal liver function tests.

BACKGROUND & AIMS: Recent data on the coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has begun to shine light on the impact of the disease on the liver. But no studies to date have systematically described liver test abnormalities in patients with COVID-19. We evaluated the clinical characteristics of COVID-19 in patients with abnormal liver test results. METHODS: Clinical records and laboratory results were obtained from 417 patients with laboratory-confirmed COVID-19 who were admitted to the only referral hospital in Shenzhen, China from January 11 to February 21, 2020 and followed up to March 7, 2020. Information on clinical features of patients with abnormal liver tests were collected for analysis. RESULTS: Of 417 patients with COVID-19, 318 (76.3%) had abnormal liver test results and 90 (21.5%) had liver injury during hospitalization. The presence of abnormal liver tests became more pronounced during hospitalization within 2 weeks, with 49 (23.4%), 31 (14.8%), 24 (11.5%) and 51 (24.4%) patients having alanine aminotransferase, aspartate aminotransferase, total bilirubin and gamma-glutamyl transferase levels elevated to more than 3× the upper limit of normal, respectively. Patients with abnormal liver tests of hepatocellular type or mixed type at admission had higher odds of progressing to severe disease (odds ratios [ORs] 2.73; 95% CI 1.19-6.3, and 4.44, 95% CI 1.93-10.23, respectively). The use of lopinavir/ritonavir was also found to lead to increased odds of liver injury (OR from 4.44 to 5.03, both p <0.01). CONCLUSION: Patients with abnormal liver tests were at higher risk of progressing to severe disease. The detrimental effects on liver injury mainly related to certain medications used during hospitalization, which should be monitored and evaluated frequently. LAY SUMMARY: Data on liver tests in patients with COVID-19 are scarce. We observed a high prevalence of liver test abnormalities and liver injury in 417 patients with COVID-19 admitted to our referral center, and the prevalence increased substantially during hospitalization. The presence of abnormal liver tests and liver injury were associated with the progression to severe pneumonia. The detrimental effects on liver injury were related to certain medications used during hospitalization, which warrants frequent monitoring and evaluation for these patients.

B cell infiltration is associated with the increased IL-17 and IL-22 expression in the lungs of patients with tuberculosis.

Although it has been recognized that ectopic follicle-like B cell aggregate formation is common in the lungs of patients with tuberculosis, the role of infiltrated B cells in human tuberculosis remains to be elucidated. In the present study, we showed that ectopic B cell aggregate formation was associated with containment of Mycobacterium tuberculosis. The area ratio of ectopic B cell aggregates was correlated with localized IL-17 mRNA expression and peripheral TGF-ß and IL-6 mRNA expression. Depletion of B cells from pleural fluid mononuclear cells resulted in significantly diminished M. tuberculosis antigen-specific IL-17 and IL-22 production, but not in IFN-γ secretion. Therefore, ectopic lung B cell formation is important for containment of M. tuberculosis, and up-regulation of IL-17 and IL-22 responses may be an important mechanism underlying the protective role B cells in human tuberculosis.

[The effect of CD4+ CD25+ regulatory T cell inactivation combined with levofloxacin on murine tuberculosis].

OBJECTIVE: To investigate the effects of inactivation of CD(4)(+)CD(25)(+) regulatory T cells (Treg) combined with the administration of levofloxacin (LFX) on the cellular immune response of murine tuberculosis. METHODS: Inactivation of Treg was achieved by intraperitoneal injection of anti-CD(25), clone PC61. Female C57BL/6 mice were divided into 4 groups, PC61 alone, LFX alone, PC61 plus LFX, and the control, with 19 mice in each group. The LFX group and the control group were treated with rat-IgG isotope control. Mice were inoculated with H(37) Rv (1 x 10(6) CFU) via the tail vein 3 days later. From the 2nd day, the LFX group and the PC61 plus LFX group received intragastric administration of LFX at 200 mg x kg(-1) x d(-1) per mouse for 45 days. Blood and spleen Tregs were measured by flow cytometry. The cellular immune response and pulmonary histopathology at different time points were also evaluated after infection. RESULTS: At the 10th and 30th day, the ratio of CD(4)(+)CD(25)(+)/CD(4)(+)T cells in the spleen was (30 +/- 4)% and (17.3 +/- 1.6)% respectively in the control group, (21 +/- 4)% and (16.1 +/- 1.3)% respectively in the PC61 group, (44 +/- 6)% and (24.7 +/- 2.0)% respectively in the LFX group, (24 +/- 3)% and (10.4 +/- 1.0)% respectively in the PC61 plus LFX group. The differences were significant between groups (q = 3.62 - 5.56, P < 0.05), but the difference between the PC61 plus LFX group and the PC61 group at the 10th day. Same results were obtained from the peripheral blood. PC61 plus LFX therapy resulted in BCG specific cytokine response (IL-17, IFN-gamma, TNF-alpha) from murine spleen cells at the 10th and the 30th day, and also in milder pathologic changes and the lowest mortality. CONCLUSIONS: The cellular immune response was enhanced by Treg inactivation and LFX therapy, which decreased the pathologic changes and the mortality of murine tuberculosis.

[Detection of cryptosporidium infection among AIDS patients in Guangdong and Yunnan].

OBJECTIVE: To investigate the infection of Cryptosporidium and its epidemiological characteristics in AIDS patients of Southern China. METHODS: Stool samples colleted from AIDS confirmed patients. The samples were detected for oocyst of Cryptosporidium by acid fast bacteria stain and indirect fluorescent antibody stain respectively, CD4 count was detected by Flow Cytometry. RESULTS: 212 samples of fresh stool obtained from the AIDS patients who live in Guangdong and Yunnan province. The total infection rate of Cryptosporidium in AIDS patients was 4.25% (9/212), the infectious rate of oocyst in the group of 50- 59-years-old was significantly higher than those in 30-39 (P < 0.01); the infectious rate of oocyst in patients with antiretroviral therapy (ART) was also significantly lower (P = 0.0000); we found the patients coinfected with Cryptosporidium with CD4 count all below 100 cells/microl. However, there were no any difference between the infectious rate to the patient's gender, areas and stool shape. CONCLUSION: AIDS patients infected by Cryptosporidium are not rare in southern China, and the infectious rate was lower than western country. Patients received ART could decrease the infectious rate of Cryptosporidium, Cryptosporidium always happen in patient whose CD4 count was very low (< 100 cells/microl).