Yong Cao

Bio: Yong Cao is an academic researcher from Huazhong University of Science and Technology. The author has contributed to research in topics: Bronchoalveolar lavage & Interleukin 5. The author has an hindex of 10, co-authored 26 publications receiving 509 citations.

Clinical and immunologic features in severe and moderate forms of Coronavirus Disease 2019

Abstract: Background Since late December, 2019, an outbreak of pneumonia cases caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, and continued to spread throughout China and across the globe. To date, few data on immunologic features of Coronavirus Disease 2019 (COVID-19) have been reported. Methods In this single-centre retrospective study, a total of 21 patients with pneumonia who were laboratory-confirmed to be infected with SARS-CoV-2 in Wuhan Tongji hospital were included from Dec 19, 2019 to Jan 27, 2020. The immunologic characteristics as well as their clinical, laboratory, radiological features were compared between 11 severe cases and 10 moderate cases. Results Of the 21 patients with COVID-19, only 4 (19%) had a history of exposure to the Huanan seafood market. 7 (33.3%) patients had underlying conditions. The average age of severe and moderate cases was 63.9 and 51.4 years, 10 (90.9%) severe cases and 7 (70.0%) moderate cases were male. Common clinical manifestations including fever (100%, 100%), cough (70%, 90%), fatigue (100%, 70%) and myalgia (50%, 30%) in severe cases and moderate cases. PaO2/FiO2 ratio was significantly lower in severe cases (122.9) than moderate cases (366.2). Lymphocyte counts were significantly lower in severe cases (0.7 × 10□/L) than moderate cases (1.1 × 10□/L). Alanine aminotransferase, lactate dehydrogenase levels, high-sensitivity C-reactive protein and ferritin were significantly higher in severe cases (41.4 U/L, 567.2 U/L, 135.2 mg/L and 1734.4 ug/L) than moderate cases (17.6 U/L, 234.4 U/L, 51.4 mg/L and 880.2 ug /L). IL-2R, TNF-α and IL-10 concentrations on admission were significantly higher in severe cases (1202.4 pg/mL, 10.9 pg/mL and 10.9 pg/mL) than moderate cases (441.7 pg/mL, 7.5 pg/mL and 6.6 pg/mL). Absolute number of total T lymphocytes, CD4+T cells and CD8+T cells decreased in nearly all the patients, and were significantly lower in severe cases (332.5, 185.6 and 124.3 × 106/L) than moderate cases (676.5, 359.2 and 272.0 × 106/L). The expressions of IFN-γ by CD4+T cells tended to be lower in severe cases (14.6%) than moderate cases (23.6%). Conclusion The SARS-CoV-2 infection may affect primarily T lymphocytes, particularly CD4+T cells, resulting in significant decrease in number as well as IFN-γ production, which may be associated with disease severity. Together with clinical characteristics, early immunologic indicators including diminished T lymphocytes and elevated cytokines may serve as potential markers for prognosis in COVID-19.

CCL2/CCR2-dependent recruitment of Th17 cells but not Tc17 cells to the lung in a murine asthma model.

Abstract: Background: Interleukin (IL)-17 has been implicated in the pathogenesis of asthma and the progression of airway inflammation Here, we used a model of allergic asthma and found that the frequencies of IL-17-secreting T helper (Th)17 and CD8 (Tc)17 cells were both significantly increased, as was the expression of the CC chemokine receptor (CCR2) on the surface of these cells CC chemokine ligand 2 (CCL2) has been shown to mediate the activation and recruitment of inflammatory cells in asthma, which are also skewed after ovalbumin (OVA) challenge However, the role of CCL2 on Th17 cells and Tc17 cells in asthma has not been illuminated Methods: Mice that were sensitized and challenged with OVA received anti-CCL2 antibody (Ab; 5 μg/day intratracheally) or CCR2 antagonist (RS504393, 2 mg/kg/day intraperitoneally) prior to the challenge Some mice received an isotype control Ab or vehicle alone We then assessed the effects of allergic asthma and anti-CCL2 Ab or CCR2 antagonist treatment on the levels of IL-17 and CCL2, the Th17 and Tc17 cell frequencies and lung tissue inflammation Results: We demonstrated that CCL2 and IL-17 levels and the frequency of Th17 and Tc17 cells in lung tissues and bronchoalveolar lavage fluid increased in the asthma group compared with the normal control mice Blocking the CCL2/CCR2 axis greatly reduced the Th17 but not the Tc17 cell frequency, and revealed a suppressive effect on airway inflammation Conclusion: These findings indicate a role for the CCL2/CCR2 axis in mediating Th17 but not Tc17 cell migration during acute allergic airway inflammation

Increased expression of aryl hydrocarbon receptor and interleukin 22 in patients with allergic asthma.

Abstract: Objectives: We sought to determine whether the aryl hydrocarbon receptor ( AhR ) and interleukin (IL)-22 may be involved in the pathogenesis of the peripheral blood mononuclear cells (PBMCs) in allergic asthmatic patients and whether their expression may be related to the severity of the disease. Methods: Blood samples were obtained from each subject with allergic asthma (n =18), controlled asthma (n =17) and healthy control s (n =12) respectively. The PBMCs were collected for AhR mRNA detection by real-time quantitative polymerase chain reaction (PCR). The plasma was collected for IL-22 protein detection by enzyme-linked immunosorbent assay (ELISA). Results: The expression of AhR mRNA in PBMCs and IL-22 protein in plasma of patients with allergic asthma were higher than those in controlled asthma cases and healthy controls. The plasma concentrations of IL-22 had negative correlation with the predicted percentage of forced expiratory volume in the first second (FEV 1 %) and the percentage of FEV 1 and forced vital capacity (FEV 1 /FVC%) and it was positively correlated with the asthma severity score (ASS) of the asthmatics. Conclusion: Our results suggested that both AhR and IL-22 might be involved in the pathogenesis of allergic asthma in human and the level of IL-22 might have some relationship with the severity of the disease.

CXCR4 inhibitor attenuates allergen-induced lung inflammation by down-regulating MMP-9 and ERK1/2.

Abstract: Chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor chemokine receptor 4 (CXCR4) have been recognized to play a crucial role in the pathogenesis of bronchial asthma, but the underlying molecular mechanisms are yet to be fully addressed. In the present report we demonstrated that CXCL12/CXCR4 signaling mediates allergic airway inflammation through induction of matrix metalloproteinase 9 (MMP-9) in a murine asthmatic model. We noted that administration of AMD3100, a specific CXCR4 antagonist, significantly attenuated OVA-induced asthmatic responses along with reduced epithelial MMP-9 expression. Our studies in a bronchial epithelial cell line, 16HBE cells, further revealed that CXCL12/CXCR4 signaling synergizes with IL-13 to enhance epithelial MMP-9 expression. Our mechanistic studies demonstrated that CXCL12/CXCR4 enhances epithelial MMP-9 expression by inducing ERK1/2 expression and activation. Together, these studies would bring novel insight into the understanding for the role of CXCL12/CXCR4 signaling in asthmatic responses during the course of bronchial asthma development.

Targeting potential drivers of COVID-19: Neutrophil extracellular traps.

Abstract: Coronavirus disease 2019 (COVID-19) is a novel, viral-induced respiratory disease that in ∼10-15% of patients progresses to acute respiratory distress syndrome (ARDS) triggered by a cytokine storm. In this Perspective, autopsy results and literature are presented supporting the hypothesis that a little known yet powerful function of neutrophils-the ability to form neutrophil extracellular traps (NETs)-may contribute to organ damage and mortality in COVID-19. We show lung infiltration of neutrophils in an autopsy specimen from a patient who succumbed to COVID-19. We discuss prior reports linking aberrant NET formation to pulmonary diseases, thrombosis, mucous secretions in the airways, and cytokine production. If our hypothesis is correct, targeting NETs directly and/or indirectly with existing drugs may reduce the clinical severity of COVID-19.

The COVID-19 Cytokine Storm; What We Know So Far.

Abstract: COVID-19 is a rapidly spreading global threat that has been declared as a pandemic by the WHO COVID-19 is transmitted via droplets or direct contact and infects the respiratory tract resulting in pneumonia in most of the cases and acute respiratory distress syndrome (ARDS) in about 15 % of the cases Mortality in COVID-19 patients has been linked to the presence of the so-called "cytokine storm" induced by the virus Excessive production of proinflammatory cytokines leads to ARDS aggravation and widespread tissue damage resulting in multi-organ failure and death Targeting cytokines during the management of COVID-19 patients could improve survival rates and reduce mortality

Cytokine Storm in COVID-19: The Current Evidence and Treatment Strategies.

Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is the pathogen that causes coronavirus disease 2019 (COVID-19). As of 25 May 2020, the outbreak of COVID-19 has caused 347,192 deaths around the world. The current evidence showed that severely ill patients tend to have a high concentration of pro-inflammatory cytokines, such as interleukin (IL)-6, compared to those who are moderately ill. The high level of cytokines also indicates a poor prognosis in COVID-19. Besides, excessive infiltration of pro-inflammatory cells, mainly involving macrophages and T-helper 17 cells, has been found in lung tissues of patients with COVID-19 by postmortem examination. Recently, increasing studies indicate that the "cytokine storm" may contribute to the mortality of COVID-19. Here, we summarize the clinical and pathologic features of the cytokine storm in COVID-19. Our review shows that SARS-Cov-2 selectively induces a high level of IL-6 and results in the exhaustion of lymphocytes. The current evidence indicates that tocilizumab, an IL-6 inhibitor, is relatively effective and safe. Besides, corticosteroids, programmed cell death protein (PD)-1/PD-L1 checkpoint inhibition, cytokine-adsorption devices, intravenous immunoglobulin, and antimalarial agents could be potentially useful and reliable approaches to counteract cytokine storm in COVID-19 patients.