Soluble immune checkpoints are dysregulated in COVID-19 and heavy alcohol users with HIV infection

Immune checkpoints (ICPs) consist of paired receptor-ligand molecules that exert inhibitory or stimulatory effects on immune defense, surveillance, regulation, and self-tolerance. ICPs exist in both membrane and soluble forms in vivo and in vitro. Imbalances between inhibitory and stimulatory membrane-bound ICPs (mICPs) in malignant cells and immune cells in the tumor immune microenvironment (TIME) have been well documented. Blockades of inhibitory mICPs have emerged as an immense breakthrough in cancer therapeutics. However, the origin, structure, production regulation, and biological significance of soluble ICPs (sICPs) in health and disease largely remains elusive. Soluble ICPs can be generated through either alternative mRNA splicing and secretion or protease-mediated shedding from mICPs. Since sICPs are found in the bloodstream, they likely form a circulating immune regulatory system. In fact, there is increasing evidence that sICPs exhibit biological functions including (1) regulation of antibacterial immunity, (2) interaction with their mICP compartments to positively or negatively regulate immune responses, and (3) competition with their mICP compartments for binding to the ICP blocking antibodies, thereby reducing the efficacy of ICP blockade therapies. Here, we summarize current data of sICPs in cancer and infectious diseases. We particularly focus on sICPs in COVID-19 and HIV infection as they are the two ongoing global pandemics and have created the worlds most serious public health challenges. A "storm" of sICPs occurs in the peripheral circulation of COVID-19 patients and is associated with the severity of COVID-19. Similarly, sICPs are highly dysregulated in people living with HIV (PLHIV) and some sICPs remain dysregulated in PLHIV on antiretroviral therapy (ART), indicating these sICPs may serve as biomarkers of incomplete immune reconstitution in PLHIV on ART. We reveal that HIV infection in the setting of alcohol abuse exacerbates sICP dysregulation as PLHIV with heavy alcohol consumption have significantly elevated plasma levels of many sICPs. Thus, both stimulatory and inhibitory sICPs are present in the bloodstream of healthy people and their balance can be disrupted under pathophysiological conditions such as cancer, COVID-19, HIV infection, and alcohol abuse. There is an urgent need to study the role of sICPs in immune regulation in health and disease.

Excessive matrix metalloproteinase-1 and hyperactivation of endothelial cells occurred in COVID-19 patients and were associated with the severity of COVID-19

COVID-19 starts as a respiratory disease that can progress to pneumonia, severe acute respiratory syndrome (SARS), and multi-organ failure. Growing evidence suggests that COVID-19 is a systemic illness that primarily injures the vascular endothelium, yet the underlying mechanisms remain unknown. SARS-CoV-2 infection is believed to trigger a cytokine storm that plays a critical role in the pathogenesis of endothelialitis and vascular injury, eventually leading to respiratory and multi-organ failure in COVID-19 patients. We used a multiplex immunoassay to systematically profile and compare 65 inflammatory cytokines/chemokines/growth factors in plasma samples from 24 hospitalized (severe/critical) COVID-19 patients, 14 mild/moderate cases, and 13 healthy controls (HCs). Patients with severe/critical and mild/moderate COVID-19 had significantly higher plasma levels of 20 analytes than HCs. Surprisingly, only one cytokine (MIF) was among these altered analytes, while the rest were chemokines and growth factors. In addition, only MMP-1 and VEGF-A were significantly elevated in hospitalized COVID-19 patients when compared to mild/moderate cases. Given that excessive MMP-1 plays a central role in tissue destruction in a wide variety of vascular diseases and that elevated VEGF-A, an EC activation marker, increases vascular permeability, we further studied MMP-1 enzymatic activity and other EC activation markers such as soluble forms of CD146, ICAM-1, and VCAM-1. We found that plasma MMP-1 enzymatic activity and plasma levels of MMP-1 and EC activation markers were highly dysregulated in COVID-19 patients. Some dysregulations were associated with patients age or gender, but not with race. Our results demonstrate that COVID-19 patients have distinct inflammatory profiles that are distinguished from the cytokine storms in other human diseases. Excessive MMP-1 and hyperactivation of ECs occur in COVID-19 patients and are associated with the severity of COVID-19.

Effect of obesity on blood pressure variation and plasma levels of nitric oxide and endothelin in elderly hypertensive patients / 中华老年医学杂志

Objective To investigate the effects of obesity on blood pressure variation and plasma levels of nitric oxide (NO) and endothelin (ET) in elderly hypertensive patients.Methods A total of 175 elderly patients with hypertension were screened for this study.Based on body mass index,they were categorized into three groups with normal weight (n =69),overweight (n=56) and obesity (n=50).24 hour dynamic blood pressure,NO and ET levels were monitored.Results No significant differences in 24 h systolic blood pressure,daytime systolic blood pressure,nighttime systolic blood pressure,24 hours diastolic blood pressure (24 h-DBP) and night time diastolic blood pressure were found among the groups (all P＞0.05).Morning systolic and diastolic blood pressure were higher in obese group than in normal weight and overweight groups(both P＜0.05).The daytime diastolic blood pressure was higher in obese group than in overweight group.24 h systolic blood pressure variation,daytime systolic blood pressure variation,and blood pressure pattern were higher in obese group than in overweight and normal weight group [(12.6 ± 2.7)％ vs.(10.4 ±2.2)％ and (9.4±1.9)％,(12.2±2.9)％ vs.(10.2±2.2)％ and (9.2±2.1)％,(5.2±10.5)％vs.(1.4± 6.9) ％ and (1.8 ± 8.2) ％ group,all P＜ 0.05].The nighttime systolic blood pressure variation,24 h diastolic blood pressure variation,daytime diastolic blood pressure variation were increased in obese group as compared with normal weight group [(9.8 ± 3.7)％ vs.(8.2 ± 3.1)％,(15.3±3.3)％ vs.(13.2±4.2)％,(14.7±3.7)％ vs.(12.9±3.8)％,all P＜0.05].No differences were found in nighttime diastolic blood pressure variation among the groups.Plasma NO level was lower in obese group than in overweight and normal weight group [(29.8± 14.2)μmol/L vs.(47.9± 18.6) μmol/L and (94.6 ± 42.9) μmol/L,P＜0.01].Plasma ET level was significantly higher in obese group than in overweight group and normal weight group [(46.5± 9.8)ng/L vs.(37.3±4.8) ng/L and (31.1± 5.5) ng/L,P＜0.01].24 h systolic blood pressure variation was significantly correlated with plasma NO level (r =0.340,P =0.004) in normal weight group.Conclusions Obesity can effectively increase blood pressure variation and ET level,and reduce plasma NO level in elderly hypertensive patients.Obesity is one of the most important influencing factors for blood pressure variation,plasma NO and ET levels.

Cytokine secretion, angiogenesis and cardiomyocyte apoptosis after transplantation of autologous bone marrow mesenchymal stem cells into myocardial infarction regions / 中国组织工程研究

AIM: The autologous bone marrow mesenchymal stem cell (BMSC) transplantation for treating acute myocardial infarction (AMI) via coronary artery in clinic has made remarkable and encouraging progress. The experiment aimed to study cytokine secretion in autologous BMSC transplantation for myocardial infarction dogs and its influence on angiogenesis and cardiomyocyte apoptosis. METHODS: Experiments were performed at the Animal Laboratory and the Central Laboratory, First Affiliated Hospital of Anhui Medical University between December 2005 and May 2007. 10 mL of bone marrow was sterilely aspirated from the posterosuperior iliac spine of 36 healthy mongrel dogs. BMSCs were isolated and purified by Percoll density gradient centrifugation and cultured in vitro by adherence method. After being co-cultured with 5-azacytidine for two passages, these cells were labeled by 5-bromodeoxyuridine (Brdu) for preparation. Dog models of AMI were established in a model control group and a cell transplantation group randomly. 2 mL of cell suspension of autologous BMSCs were implanted into four different regions in the acute myocardial site via topical injection in the cell transplantation group, while the same dose of DMEM was injected into the corresponding regions in the model control group. Myocardial infraction tissues were measured after transplantation. RESULTS: Flow cytometry demonstrated that the positive rate of CD34 and CD11b on third passage of BMSC cell surface was below 5%, while the positive rate of CD44 and CD105 was above 90%. In situ end labeling showed that apoptotic index of cardiomyocytes was lower in the cell transplantation group than in the model control group (P

CONSTRUCTION OF HYBRID NUCLEIC ACID VACCINES BASED ON PLASMODIUM FALCIPARUM MEROZOITE SURFACE PROTEIN1BLOCK17REGION / 中国寄生虫学与寄生虫病杂志

AIM:To construct hybrid nucleic acid vaccines which contain Plasmodium falciparum merozoite surface protein 1 (MSP1 ) block 1 7gene and gene fragment coding for several T cell epitopes. METHODS:MSP1 block 1 7gene of FUP strain was connected with a polyvalent gene fragment which contains several T cell epitopes from MSA1 ,MSA2 ,RESA,IL- 1 and Tetanus toxin,the connected gene fragment (hybrid gene,HG) was cloned into eukaryotic expression plasmid p CDNA3.1 (- ) ,VR1 0 1 2 for intracellular expression,VR1 0 1 2 /TPA for secretion,the recombinants were identified by PCR and restriction enzyme digestion. RE- SUL TS &CONCLUSION:The hybrid nucieic acid vaccines:VR1 0 1 2 /HG,VR1 0 1 2 /TPA/ HG and p CDNA3.1 /HG were successfully constructed.

Identification of glycoprotein C of herpes simplex virus / 中国免疫学杂志

A group of glycoproteins with ⅥW 105- 130 K D from BHK-21 cell infected with Herpes Simplex Virus (HSV) were precipitated by six monoclonal antibodies (McAb). 1 A 12. Mad-2, 2D11, CM-D3, 2A8 and lC4,by using immunoprecipate technique. Im munoassays of BHK-21 cells infected with HSV-1/HSV-2 intertypic recom binants localized the genes encoding the target antigens of 1 A12, Mad-2, 2Dll, CM-D3, 2A8 and 1 C4 to the unique long region of HSV genesome at mapping unit 0.536—0.682 overlapping the gene encoding glycoprotein C(gC). De pending on reactivity with HSV- 1 and HSV-2 infected BHK-21 cells, Mad-2 shows HSV type-1 specificity, C M-D 3 shows HSV ty pe-2 specificity and the other four McAbs show type-common spe. cifity. So Mad-2 is against gC-1, CM D3 is against gC - 2 and 1 A12, 2 A8, 2 D11, 1 C4 are against type-common gC. We labelled the four McAbs directed at type-common gC with horseradise peroxidase (HRP)by the modified method of Nakane. ELISA blocking test was done to test the relationships of them. The result is that those four McAbs are against four distinct antigenic sites on type-common gC.