Low Immune Response Research Articles

Impacts of delta and omicron variants on inactivated SARS‐CoV‐2 vaccine‐induced T cell responses in patients with autoimmune diseases and healthy controls

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes coronavirus disease 2019 (COVID-19), which is still devastating economies and communities globally. The increasing infections of variants of concern (VOCs) in vaccinated population have raised concerns about the effectiveness of current vaccines. Patients with autoimmune diseases (PAD) under immunosuppressant treatments are facing higher risk of infection and potentially lower immune responses to SARS-CoV-2 vaccination. Blood samples were collected from PAD or healthy controls (HC) who finished two or three doses of inactivated vaccines. Spike peptides derived from wild-type strain, delta, omicron BA.1 were utilisedto evaluate T cell responses and their cross-recognition of delta and omicron in HC and PAD by flow cytometry and ex vivo IFNγ-ELISpot. We found that inactivated vaccine-induced spike-specific memory T cells were long-lasting in both PAD and HC. These spike-specific T cells were highly conserved and cross-recognized delta and omicron. Moreover, a third inactivated vaccine expanded spike-specific T cells that responded to delta and omicron spike peptides substantially in both PAD and HC. Importantly, the polyfunctionality of spike-specific memory T cells was preserved in terms of cytokine and cytotoxic responses. Although the extent of T cell responses was lower in PAD after two-dose, T cell responses were boosted to a greater magnitude in PAD by the third dose, bringing comparable spike-specific T cell immunity after the third dose. Inactivated vaccine-induced spike-specific T cells remain largely intact against delta and omicron variants. This study expands our understanding of inactivated vaccine-induced T cell responses in PAD and HC, which could have important indications for vaccination strategy.

A comprehensive analysis of the FOX family for predicting kidney renal clear cell carcinoma prognosis and the oncogenic role of FOXG1.

Previous studies have confirmed that the forkhead box (FOX) superfamily of transcription factors regulates tumor progression and metastasis in multiple cancer. The purpose of this study was to develop a model based on FOX family genes for predicting kidney renal clear cell carcinom (KIRC) prognosis. We downloaded the transcriptional profiles and clinical data of KIRC patients from the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) datasets. To build a new prognosis model, we screened prognosis-related FOX family genes using Lasso regression and Multivariate Cox regression analyses. Receiver operating characteristic (ROC) curves were used to evaluate model performance. Additionally, a prognostic nomogram was developed using clinical information and selected genes to improve the accuracy of prognostic prediction. We also investigated whether prognosis-related FOX family genes are related to the immune response in KIRC. Finally, we validated the oncogenic role of FOXG1 in KIRC using an in vitro tumor function assay. Six prognosis-related FOX family genes were screened: FOXO1, FOXM1, FOXK2, FOXG1, FOXA1, and FOXD1. The ROC curves indicated that our model was capable of making accurate predictions for 1-, 3-, and 5-year overall survival (OS). The nomogram further improved the accuracy of prognostic predictions. In addition, compared to those in patients with low-risk scores, high-risk scores predicted a decreased level of immune cell infiltration and a lower immune response rate. Moreover, the results of in vitro studies confirmed that FOXG1 supports the proliferation and invasion of KIRC.

1969. SARS-CoV-2 seroprevalence among patients with cancer and healthcare workers from an oncology referral center during the first year of COVID-19 vaccination in Mexico

Abstract Background Cancer patients (CPs) with COVID-19 have an increased risk of adverse outcomes. In addition, CPs seem to have a lower immune response to SARS-CoV-2 vaccination. This study aimed to evaluate SARS-CoV-2 spike antibodies (anti-S Abs) following COVID-19 vaccination in CPs and healthcare workers (HCWs). Methods We conducted a point-seroprevalence study in CPs and HCWs who received a two-dose scheme with either BNT162b2, AZD1222, or Sputnik-V vaccine. We measured anti-S Abs by quantitative immunoassay to assess humoral immune response. Besides, we quantified anti-nucleocapsid antibodies in a subgroup of individuals to determine prior infection. We compared anti-S Abs titers in both groups and stratified by vaccine type, prior infection, and clinical characteristics. We conducted a multivariate logistic regression to determine variables associated with a poor humoral response. Results Six hundred forty-one individuals were included: 174 (27%) CPs and 467 (73%) HCWs. The median anti-S Abs titter was higher among HCWs compared to CPs (2568 U/mL vs. 1807 U/mL, p=0.002). Both CPs and HCWs with prior infection had higher anti-S Abs titter (p< 0.001). Regardless of the time since vaccination, a higher proportion of subjects with titers < 250 U/mL was observed in CPs (p< 0.001) (Fig 2). In the multivariate analysis, older age (p=0.036), AZD1222 (p=0.003), and Sputnik-V (p=0.020) were associated with lower humoral response among the entire cohort. SARS-CoV-2 spike antibody titers among cancer patients and healthcare workers. Global differences in anti-S Abs titers between CPs and HCWs groups (a) and antibody titers in CPs and HCWs groups stratified by type of received vaccine (b). Abbreviations: CP: Cancer patients, HCW: Healthcare workers. SARS-CoV-2 spike antibody titers according to time since vaccination among cancer patients and healthcare workers. Abbreviations: CP: Cancer patients, HCW: Healthcare workers. Conclusion In this study, both CPs and HCWs showed an adequate response to vaccination; however, CPs had lower anti-S Abs titers and a faster decline over time. Based on our results, new strategies should be assessed to sustain the humoral response to vaccination and thus decrease the COVID-19 burden among the oncologic population. Disclosures All Authors: No reported disclosures.

Exploring in vitro expression and immune potency in mice using mRNA encoding the Plasmodium falciparum malaria antigen, CelTOS.

The secreted malarial protein, Cell-Traversal protein for Ookinetes and Sporozoites (CelTOS), is highly conserved among Plasmodium species, and plays a role in the invasion of mosquito midgut cells and hepatocytes in the vertebrate host. CelTOS was identified as a potential protective antigen based on a proteomic analysis, which showed that CelTOS stimulated significant effector T cells producing IFN-γ in peripheral blood mononuclear cells (PBMCs) from radiation attenuated sporozoite-immunized, malaria-naïve human subjects. In a rodent malaria model, recombinant full-length CelTOS protein/adjuvant combinations induced sterile protection, and in several studies, functional antibodies were produced that had hepatocyte invasion inhibition and transmission-blocking activities. Despite some encouraging results, vaccine approaches using CelTOS will require improvement before it can be considered as an effective vaccine candidate. Here, we report on the use of mRNA vaccine technology to induce humoral and cell-mediated immune responses using this antigen. Several pfceltos encoding mRNA transcripts were assessed for the impact on protein translation levels in vitro. Protein coding sequences included those to evaluate the effects of signal sequence, N-glycosylation on translation, and of nucleoside substitutions. Using in vitro transfection experiments as a pre-screen, we assessed the quality of the expressed CelTOS target relative to the homogeneity, cellular localization, and durability of expression levels. Optimized mRNA transcripts, which demonstrated highest protein expression levels in vitro were selected for encapsulation in lipid nanoparticles (LNP) and used to immunize mice to assess for both humoral and cellular cytokine responses. Our findings indicate that mRNA transcripts encoding pfceltos while potent for inducing antigen-specific cellular cytokine responses in mice, were less able to mount PfCelTOS-specific antibody responses using a two-dose regimen. An additional booster dose was needed to overcome low seroconversion rates in mice. With respect to antibody fine specificities, N-glycosylation site mutated immunogens yielded lower immune responses, particularly to the N-terminus of the molecule. While it remains unclear the impact on CelTOS antigen as immunogen, this study highlights the need to optimize antigen design for vaccine development.

Gene therapy of glaucoma: Just an attractive experimental approach?

AbstractIn recent years, much progress has been made in the identification of the genes involved in the physiology of glaucoma and the development of new gene‐based therapies. The eyeball has ideal characteristics for gene therapy due to its location and immunological properties. Gene delivery through viral and particle‐based vectors to target tissues makes gene therapy a more specific and effective treatment than existing conventional treatments. Experimental gene therapy strategies for glaucoma primarily targets trabecular meshwork (TM) (to decrease intraocular pressure) and retinal ganglion cells (for neuroprotection).A chronic disease such as glaucoma, requires the use of vectors that allow long‐term gene expression with low toxicity and immune response. Some examples of experimental gene therapy for glaucoma are the efficient transduction of self‐complementary adeno‐associated viruses – metalloproteinase 1 (MMP1) into the TM in a steroid‐induced ocular hypertension model in sheep1. On the other hand, different studies have reported an increased survival of retinal ganglion cells after a single intravitreal injection of adenoviruses carrying brain‐derived neurotrophic factor (BDNF) in a rat model of glaucoma2.To develop gene therapy at a therapeutic level it is necessary to broaden our knowledge of the expression and regulation mechanisms of candidate genes in order to control the efficiency and stability of their effect. The specificity of the vectors and the safety to prevent their spread to the rest of the organism must also be improved. Thus, it is necessary to continue devoting efforts to the development of safe and effective gene therapy for glaucoma.

Possibilities of regulating the reaction of tissues of the implantation area with pyrimidine preparations after prosthetic repair of the hernia ring in the experiment

Purpose of the study. Study of the possibilities of pharmacological regulation of local and systemic inflammatory response, stimulation of reparative regeneration in prosthetic repair of abdominal wall hernias.Materials and methods. The experiment was carried out on 92 rats of both sexes of a pure line, divided into 4 groups. Group I (control) received only 1 ml of 0.9 % sodium chloride solution. Group II – hydroxyethyldimethyldihydropyrimidine 21 mg/day. Group III – potassium orotate 10.5 mg/day. Group IV – methyluracil 14 mg/day. Under anesthesia a mesh implant 4 × 2 cm was placed in the layer between the hypodermis and the superficial fascia. Animals were withdrawn from the experiment on days 5 (n = 52) and 14 days (n = 40). The site of implantation for histomorphometric studies captured the dermis, hypodermis, implant layer, fascia, and muscle. The preparation and staining of the preparations were carried out with hematoxylin-eosin and by Mallory.Results. 1. On the 5th day after the operation group II (hydroxyethyldimethyldihydropyrimidine) was characterized by pronounced neovasculogenesis (p = 0.002, U-test) and more active processes of formation and maturation of connective tissue (p = 0.024, U-test) with a low immune response to a foreign body (p = 0.044, U- test). III (potassium orotate) and IV groups (methyluracil) were characterized by a pronounced decrease in the inflammatory response with a simultaneous increase in tissue edema (p < 0.001, U-test), slowing down the formation and maturation of connective tissue (p = 0.016, U-test). 2. On the 14th day after the operation, group II (hydroxyethyldimethyldihydropyrimidine) was characterized an increase in the area of neovasculogenesis by 208.0 % (p < 0.001, U -criterion), a decrease in the volume of fluid accumulations by 63.4 % (p < 0.001, U-criterion), an increase in the processes of formation and maturation of connective tissue, mainly due to an increase in the number of fibrocytes by 333.3 % (p < 0.001, U-criterion). The parameters of the immune response to a foreign body had significant differences (p < 0.001, U-test).Conclusion. The use of potassium orotate and methyluracil reduces the inflammatory response in the tissues of the implantation area, however, it is associated with the appearance of liquid components and with a decrease in the formation of connective tissue cells. The use of hydroxyethyldimethyldihydropyrimidine is devoid of the above disadvantages, it is characterized by the predominance of regeneration and neovasculogenesis processes, which allows it to be used as a pharmacological support drug for prosthetic hernioplasty.

Organic copper promoted copper accumulation and transport, enhanced low temperature tolerance and physiological health of white shrimp (Litopenaeus vannamei Boone, 1931)

This study was conducted to assess the effects of dietary copper source and level on hematological parameters, copper accumulation and transport, resistance to low temperature, antioxidant capacity and immune response of white shrimp (Litopenaeus vannamei Boone, 1931). Seven experimental diets with different copper sources and levels were formulated: C, no copper supplementation; S, 30 mg/kg copper in the form of CuSO4·5H2O; SO, 15 mg/kg copper in CuSO4·5H2O + 7.5 mg/kg copper in Cu-proteinate; O1, O2, O3 and O4, 10, 20, 30 and 40 mg/kg copper in the form of Cu-proteinate, respectively. A total of 840 shrimp (5.30 ± 0.04 g) were randomly distributed to 21 tanks (3 tanks/diet, 40 shrimp/tank). An 8-week feeding trial was conducted. The results showed that there was no significant difference in growth performance and whole shrimp chemical compositions among all groups. Compared with inorganic copper, dietary organic copper (O2 and O3) increased total protein, albumin, and glucose content of plasma, while decreased triglyceride and total cholesterol of plasma. Copper concentration in plasma and muscle and gene expression of metallothionein and copper-transporting ATPase 2 like in hepatopancreas were higher in shrimp fed organic copper (SO, O2, O3 and O4). The lowest mortality after low temperature (10 °C) challenge test was observed in the O2 and O3 groups. Organic copper (SO, O2, O3 and O4) significantly enhanced the antioxidant capacity (in terms of higher activities of total superoxide dismutase, copper zinc superoxide dismutase, catalase, glutathione peroxidase and total antioxidant capacity, lower malondialdehyde concentration of plasma, and up-regulated gene expression of superoxide dismutase, copper zinc superoxide dismutase, catalase and glutathione peroxidase of hepatopancreas). Organic copper (SO, O2, O3 and O4) enhanced the immune response (in terms of higher number of total hemocytes, higher activities of acid phosphatase, alkaline phosphatase, phenoloxidase, hemocyanin and lysozyme in plasma, and higher gene expressions of alkaline phosphatase, lysozyme and hemocyanin in hepatopancreas). Inorganic copper (Diet S) also had positive effects on white shrimp compared with the C diet, but the SO, O2, O3 and O4 diets resulted in better results, among which the O2 diet appeared to be the best one. In conclusion, organic copper was more beneficial to shrimp health than copper sulfate.

TMIC-03. TUMOR INFILTRATING LYMPHOCYTES IN BRAIN METASTASIS: CLINICOPATHOLOGICAL EVALUATION AND COMPARISON WITH PAIRED PRIMARY

Abstract INTRODUCTION Little is known about tumour-infiltrating lymphocytes (TILs) in brain metastasis (BM) and their utility as predictive biomarker for immunotherapy. AIM: To analyze TILs in BM, and correlate with corresponding paired primary (PP). METHODS Inclusion: Histologically confirmed BM and PP (2015-2020). Exclusion: Hematological malignancies, spinal cord/meningeal metastasis, pediatric age, slides/blocks not available. Final Nf 277 BM; 64 PP. One H&E slide from both PP &BM assessed for stromal TILs (sTILs) and intratumoral TILs (iTILs) as per International TIL Working Group guidelines. RESULTS Median sTILs (10%) were significantly higher than iTILs (1%) in primary and BM (p-value < 0.001). sTILs were mild (<10%) in majority of primary (57.8%) and BM (59.9%), while iTILs were nearly always mild (primary 97.1%; BM 96.9%). Between PP and BM, no change in sTIL category in 48.43%, while conversion in 51.56%, with higher to lower conversion (66.67%) > lower to higher (33.33%). Conversion rate higher for breast (54.3%) &GIT (62.5%) than lung (45.5%) &GUT (40%). In BM, preoperative steroid therapy (PST) showed lower sTILs (≤10%) (p-value= 0.041), and adenocarcinoma histology higher sTILs ( >10%) (p-value= 0.001), while precocious metastasis (p-value= 0.051) and absence of extracranial metastasis (p-value= 0.083) trended towards higher sTILs. Median survival of whole cohort was 20 months (95% CI 14.4-25.68 months). Presence of extracranial metastasis (p-value= 0.01); precocious BM (p-value= 0.007) showed lower overall survival (OS), while adenocarcinoma histology better OS (p-value= 0.029), in both univariate and multivariate analysis. Absence of PST showed longer median survival, though not significant (24.1 vs 19.8months; p-value= 0.19). CONCLUSIONS sTILs predominantly show high >low conversion between PP and BM, signifying lowered immune response in BM. Thus, evaluation of sTILs in BM, wherever tissue available, may be indicated if immunotherapy is considered. Parameters with higher sTILs showed longer survival, possibly indicating prognostic role of tumor microenvironment in BM.

Screening the potential part of the G protein antigen is an achievable strategy to improve the immune effect of DNA vaccine against MSRV infection

DNA vaccines, as an effective prophylactic technology to induce both humoral and cellular immune responses, have already been widely studied to prevent and control viral and bacterial infections in aquaculture. To find a more effective and safer way to control Micropterus salmoides rhabdovirus (MSRV) infection in largemouth bass, two different DNA vaccines expressing partial (pcDNA3.1-G2) and full-length (pcDNA3.1-G) of the MSRV G protein were developed and injected intramuscularly with different doses. The immune effect was comprehensively compared and evaluated by detecting immune-related parameters including serum antibody levels, immune-related physiological indexes, immune-related gene expression and relative survival rates in this study. The results showed that compared with the pcDNA3.1-G vaccine, the pcDNA3.1-G2 vaccine induced higher serum antibody levels, a lower nonspecific immune response in serum (ACP, SOD and T-AOC activities), higher immune-related gene expression and a higher relative survival rate. Moreover, the immune effect of pcDNA3.1-G2-vaccinated fish showed gradually higher with the increasing pcDNA3.1-G2 concentration, especially in pcDNA3.1-G2 (10μg/per fish) group, the relative survival rate reached to 82.5%, which was significant higher (p < 0.05) than pcDNA3.1-G (10μg/per fish) group. This study indicated that screening the potential core part of an antigen is an achievable strategy to improve the immunogenicity and immunoprotective effect of DNA vaccine.

Hesitancy toward the Full COVID-19 Vaccination among Kidney, Liver and Lung Transplant Recipients in Italy.

Coronavirus disease 2019 (COVID-19) vaccination hesitancy is a threat as COVID-19 vaccines have reduced both viral transmission and virus-associated mortality rates, particularly in high-risk subgroups. Solid organ transplant recipients (SOTRs) are particularly vulnerable, as the underlying causes of their organ failure and the chronic immunosuppression are associated with a lower immune response to COVID-19 vaccines, and with an excessive risk of death due to SARS-CoV-2 infection. We aimed to evaluate COVID-19 vaccination hesitancy and its reasons in a population of SOTRs. All the SOTRs attending our post-transplant clinics were asked to fill in a vaccination status form with specific validated questions related to their willingness to receive a third vaccine dose. In the case of negative answers, the patients were encouraged to explain the reasons for their refusal. Among the SOTRs (1899), 1019 were investigated (53.7%). Overall, 5.01% (51/1019) of the SOTRs raised concerns regarding the future third dose vaccination. In more detail, hesitancy rates were 3.3% (15/453), 4.2% (7/166), and 7.3% (29/400) among the investigated liver, lung, and kidney transplant recipients, respectively (p = 0.0018). The main reasons for hesitancy were fear of adverse events (30/51, 58.8%) and perceived lack of efficacy (21/51, 41.2%). Full adherence to ongoing or future vaccination campaigns is crucial to prevent, or at least reduce, COVID-19-related morbidity and mortality in fragile patients. The identification of the reasons influencing COVID-19 vaccination hesitancy in these patients is very important to establish appropriate and targeted patient-doctor communication strategies, and to further implement specific vaccination campaigns.

Durability of antibodies post vaccination with two doses of inactivated BBIBP-CorV vaccine

Background Breakthrough infections post-COVID-19 vaccination occur with the emerging variants of the SARS-CoV virus which might be either due to the newer variants escaping immune response or the waning of antibodies over time. However, there is lack of long-term follow-up evidence on the waning of immune response following inactivated COVID-19 vaccine. Methods A retrospective, observational study was conducted on serum samples of individuals who had received two doses of BBIBP-CorV vaccine. Individual’s antibody responses were evaluated based on IgG anti-S and neutralizing antibodies measurements. Antibody samples were categorized into four groups, defined by the time interval from the individual’s receipt of the BBIBP-CorV vaccine: <30 days, 30–90 days, 91–180 days and >180 days. Results A total of 6668 serum samples from inactivated BBIBP-CorV vaccine recipients were analyzed for IgG anti-S and neutralizing antibodies. 571 (8.6%) samples were tested during the first 29 days interval post vaccination, 3642 (54.6%) were tested during 30–90 days interval, 2173 (32.6%) samples were tested during 91 to 180 days interval and 282(4.2%) were tested at >180 days interval post vaccination. We found that more than 50% of the individuals had antibody titers below the average cut-off range at the 91–180 days interval post vaccination. Older age (>60 years), male gender, chronic kidney disease, hypertension, immunodeficiencies and increased interval post vaccination emerged as independent risk factors associated with lower immune response. Conclusion Inactivated BBIBP-CorV vaccine recipients, based on age, gender and associated comorbid conditions might need booster doses at an earlier interval than the currently followed six months interval.

Analysis of Risk Factors for a Low Immune Response to Messenger RNA COVID-19 Vaccine in Kidney Transplant Recipients and Differences Between Second and Third Dose

INTRODUCTIONThe efficacy of the response to SARS-CoV-2 vaccination in kidney transplant recipients is low. The aim of our study was to evaluate the risk factors correlated with the low antibody response and whether there was an improvement between the second and the third dose.MATERIALS AND METHODSA prospective study was conducted on 176 kidney transplant recipients, who received the second and the third dose of the anti-SARS-CoV-2 mRNA Comirnaty vaccine. We evaluated the seroconversion process after administration of the second and the third dose and assessed a possible correlation with age, time between transplantation and vaccination and type of immunosuppressive therapy.RESULTS98 out of the 176 (55.7%) patients responded positively after the inoculation of the second dose and according to the multivariable logistic regression analysis the lack of seroconversion was independently associated with patient age ≥60 (p=0.025, OR=2.094), time since transplantation of 1-3 months (p=0.032, OR=2.118) and triple therapy (p=0.044, OR=2.327). After the vaccine third dose the seroconversion increased to 62.5% and it was negatively influenced by Calcineurin inhibitors (CNI) use (12/21, 57.1% vs. 71/78, 91.0%, p=0.0006), and triple therapy (13/21, 61.9% vs. 72/78, 92.3%, p=0.0014). The median of anti-spike Ab response significantly increased from 18.5UI/ml after the 2nd dose to 316.9UI after the 3rd dose (p<0.0001).DISCUSSION AND CONCLUSIONSWe demonstrated a correlation between older age, short distance from the transplant and triple immunosuppressive therapy with the lack of seroconversion. We noticed a significant improvement in antibody response by a third dose of mRNA vaccine.

The role of milk-derived exosomes in the treatment of diseases.

Exosomes (EXOs) are natural nanoparticles of endosome origin that are secreted by a variety of cells in the body. Exosomes have been found in bio-fluids such as urine, saliva, amniotic fluid, and ascites, among others. Milk is the only commercially available biological liquid containing EXOs. Proof that exosomes are essential for cell-to-cell communication is increasingly being reported. Studies have shown that they migrate from the cell of origin to various bioactive substances, including membrane receptors, proteins, mRNAs, microRNAs, and organelles, or they can stimulate target cells directly through interactions with receptors. Because of the presence of specific proteins, lipids, and RNAs, exosomes act in physiological and pathological conditions in vivo. Other salient features of EXOs include their long half-life in the body, no tumorigenesis, low immune response, good biocompatibility, ability to target cells through their surface biomarkers, and capacity to carry macromolecules. EXOs have been introduced to the scientific community as important, efficient, and attractive nanoparticles. They can be extracted from different sources and have the same characteristics as their parents. EXOs present in milk can be separated by size exclusion chromatography, density gradient centrifugation, or (ultra) centrifugation; however, the complex composition of milk that includes casein micelles and milk fat globules makes it necessary to take additional issues into consideration when employing the mentioned techniques with milk. As a rich source of EXOs, milk has unique properties that, in addition to its role as a carrier, promotes its use in treating diseases such as digestive problems, skin ulcers, and cancer, Moreover, EXOs derived from camel milk are reported to reduce the risk of oxidative stress and cancer. Milk-derived exosomes (MDEs) from yak milk improves gastrointestinal tract (GIT) development under hypoxic conditions. Furthermore, yak-MDEs have been suggested to be the best treatment for intestinal epithelial cells (IEC-6 cell line). Because of their availability as well as the non-invasiveness and cost-effectiveness of their preparation, isolates from mammals milk can be excellent resources for studies related to EXOs. These features also make it possible to exploit MDEs in clinical trials. The current study aimed to investigate the therapeutic applications of EXOs isolated from various milk sources.

Construction and evaluation of a self-replicative RNA vaccine against SARS-CoV-2 using yellow fever virus replicon.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global threat. To forestall the pandemic, developing safe and effective vaccines is necessary. Because of the rapid production and little effect on the host genome, mRNA vaccines are attractive, but they have a relatively low immune response after a single dose. Replicon RNA (repRNA) is a promising vaccine platform for safety and efficacy. RepRNA vaccine encodes not only antigen genes but also the genes necessary for RNA replication. Thus, repRNA is self-replicative and can play the role of an adjuvant by itself, which elicits robust immunity. This study constructed and evaluated a repRNA vaccine in which the gene encoding the spike (S) protein of SARS-CoV-2 was inserted into a replicon of yellow fever virus 17D strain. Upon electroporation of this repRNA into baby hamster kidney cells, the S protein and yellow fever virus protein were co-expressed. Additionally, the self-replication ability of repRNA vaccine was confirmed using qRT-PCR, demonstrating its potency as a vaccine. Immunization of C57BL/6 mice with 1 μg of the repRNA vaccine induced specific T-cell responses but not antibody responses. Notably, the T-cell response induced by the repRNA vaccine was significantly higher than that induced by the nonreplicative RNA vaccine in our experimental model. In the future, it is of the essence to optimize vaccine administration methods and improve S protein expression, like protection of repRNA by nanoparticles and evasion of innate immunity of the host to enhance the immune-inducing ability of the repRNA vaccine.

Photodynamic amplified immune checkpoint-blockade therapy of self-delivery bioregulator via epigenetic reprogramming

Photodynamic therapy (PDT) and immunotherapy have unique advantages for primary and metastatic tumor treatment. However, immunosuppressive tumor microenvironment (ITM) causes low immune responses and various degrees of therapeutic resistance. In this work, a self-delivery bioregulator (C-Moc) is developed for photodynamic amplified immune checkpoint-blockade (ICB) therapy by epigenetic reprogramming. To be specific, carrier-free C-Moc is prepared by the self-assembly of chlorine e6 (Ce6) and mocetinostat (Moc) in the presence of DSPE-PEG2000 through electrostatic and hydrophobic interactions. Of note, nanosized C-Moc has an improved stability, cellular uptake and pharmacokinetics behaviors. Intravenously injected C-Moc prefers to accumulate at tumor site and then penetrate into tumor tissues upon light irradiation. Meanwhile, the initiated PDT would kill tumor cells for primary tumor inhibition and also induce immunogenic cell death (ICD) to activate antitumor immunity. More importantly, C-Moc is able to increase the expressions of MHC-I and PD-L1 to regulate ITM by epigenetic reprogramming, which would promote the recognition of immune system to MHC-I overexpressed tumor cells and enhance the ICB therapy of α-PD-L1. This photodynamic amplified ICB therapy of C-Moc shows a great superiority over the single treatment on primary and distant tumor suppression.

Clinical diagnosis and etiology of patients with Chlamydia psittaci pneumonia based on metagenomic next-generation sequencing.

The incidence of severe Chlamydia psittaci (C. psittaci) pneumonia and coinfections is increasing. Early detection of this condition is needed to prevent negative outcomes, along with detailed descriptions of its associated clinical characteristics. Our study contributes by undertaking etiological analysis of patients with C. psittaci pneumonia based on metagenomic next-generation sequencing (mNGS). A retrospective analysis of 30 patients with C. psittaci pneumonia was undertaken and confirmed by mNGS or polymerase chain reaction (PCR). Clinical manifestations of the severe and non-severe C. psittaci pneumonia groups were compared for clinical reference. Etiological analyses were also performed to comprehensively understand pathogeny and coinfection with other respiratory pathogens in C. psittaci patients. The absolute value of lymphocytes (LYM) in the severe group was lower than in the non-severe group. At the same time, neutrophil-to-lymphocyte ratio (NLR), procalcitonin (PCT), alanine aminotransferase (ALT), D-II polymer, brain natriuretic peptide (BNP), myoglobin (MYO), and cardiac troponin I (cTnI) were significantly higher (P < 0.05) in the severe group. mNGS has a broader pathogen spectrum and can more sensitively detect C. psittaci and other low-abundance pathogens with a higher positive detection rate (100%, 13/13 vs. 46%, 6/13, P <0.05) than conventional culture methods. mNGS detected the following dominant species associated with C. psittaci in patients: bacteria (53.2%, 39% gram-positive, 61% gram-negative), fungi (12.9%), and viruses (33.9%). A total of 73.3% (11/15) of patients had suspected coinfections, with a coinfection rate of 91.7% (11/12) in the severe group. No coinfection or death occurred in the non-severe group. Prognosis in the severe group was poor, with a mortality rate of 27.3% (3/11) for patients with coinfection. Eight of 11 patients with coinfections (72.7%) recovered. In conclusion, the clinical symptoms of severe C. psittaci pneumonia manifested as abnormal inflammatory indicators, impaired liver function, myocardial injury, coagulation, and relatively low immune responses. The higher proportion of patients with coinfections in our study supports the use of mNGS for comprehensive early detection of respiratory infections in patients with C. psittaci pneumonia. Simultaneous early identification of coinfections would further improve the clinical treatment of these patients.

Comparison of endoparasite abundance and species richness of two Roosevelt elk herds in northern California

Roosevelt elk (Cervus canadensis roosevelti) have historically populated the Pacific Northwest from the Olympic Peninsula to the south of San Francisco Bay, and several management actions have supported restoring elk into parts of this historic range. In 1982, 17 Roosevelt elk were translocated from Gold Bluffs Beach State Park to Sinkyone Wilderness State Park. In 2020, the Sinkyone elk herd was observed to have lower body condition scores and poor coat conditions in comparison to the Gold Bluffs Beach elk herd. Therefore, the objectives of this study were to investigate the difference in health between the two herds. Fecal samples were collected (n = 20) from each herd to measure species richness and abundance of parasites. We determined there was a significant difference in species richness and abundance of parasite eggs between the two herds. The Sinkyone herd's overall higher endoparasite load may be attributed to a low immune response due to low nutrition but, causation is unknown.

CSPG4 expression in soft tissue sarcomas is associated with poor prognosis and low cytotoxic immune response

BackgroundSoft tissue sarcomas (STS) are heterogeneous and pro-metastatic tumors. Identification of accurate prognostic factors and novel therapeutic targets are crucial. CSPG4 is a cell surface proteoglycan with oncogenic functions. It recently emerged as a potential target for immunotherapy, including cell therapy based on CSPG4-specific chimeric antigen receptor (CAR)-redirected cytokine-induced killer lymphocytes (CSPG4-CAR.CIKs) in STS. However, expression of CSPG4 is poorly known in STS so far.MethodsWe analyzed CSPG4 gene expression in 1378 localized STS clinical samples, and searched for correlations with clinicopathological data, including disease-free survival (DFS), and with tumor immune features.ResultsCSPG4 expression was heterogeneous across samples. High expression was associated with younger patients’ age, more frequent undifferentiated pleomorphic sarcoma and myxofibrosarcoma pathological subtypes, more frequent internal trunk tumor site, and more CINSARC high-risk samples. No correlation existed with pathological tumor size and grade, and tumor depth. Patients with high CSPG4 expression displayed 49% (95% CI 42–57) 5-year DFS versus 61% (95% CI 56–68) in patients with low expression (p = 3.17E−03), representing a 49% increased risk of event in the “CSPG4-high” group (HR = 1.49, 95% CI 1.14–1.94). This unfavorable prognostic value persisted in multivariate analysis, independently from other variables. There were significant differences in immune variables between “CSPG4-high” and “CSPG4-low” tumors. The "CSPG4-low" tumors displayed profiles suggesting higher anti-tumor cytotoxic immune response and higher potential vulnerability to immune checkpoint inhibitors (ICI). By contrast, the "CSPG4-high" tumors displayed profiles implying an immune-excluded tumor microenvironment, potentially induced by hypoxia, resulting from an immature chaotic microvasculature, and/or the presence of contractile myofibroblasts.ConclusionsPatients with “CSPG4-high” STS, theoretically candidate for CAR.CIKs, display shorter DFS and an immune environment unfavorable to vulnerability to CAR.CIKs, which could be improved by combining anti-angiogenic drugs able to normalize the tumor vasculature. By contrast, “CSPG4-low” STS are better candidates for immune therapy involving ICI.

Hybrid heart valves with VEGF-loaded zwitterionic hydrogel coating for improved anti-calcification and re-endothelialization.

With the aging of the population in worldwide, valvular heart disease has become one of the most prominent life-threatening diseases in human health, and heart valve replacement surgery is one of the therapeutic methods for valvular heart disease. Currently, commercial bioprosthetic heart valves (BHVs) for clinical application are prepared with xenograft heart valves or pericardium crosslinked by glutaraldehyde. Due to the residual cell toxicity from glutaraldehyde, heterologous antigens, and immune response, there are still some drawbacks related to the limited lifespan of bioprosthetic heart valves, such as thrombosis, calcification, degeneration, and defectiveness of re-endothelialization. Therefore, the problems of calcification, defectiveness of re-endothelialization, and poor biocompatibility from the use of bioprosthetic heart valve need to be solved. In this study, hydrogel hybrid heart valves with improved anti-calcification and re-endothelialization were prepared by taking decellularized porcine heart valves as scaffolds following grafting with double bonds. Then, the anti-biofouling zwitterionic monomers 2-methacryloyloxyethyl phosphorylcholine (MPC) and vascular endothelial growth factor (VEGF) were utilized to obtain a hydrogel-coated hybrid heart valve (PEGDA-MPC-DHVs@VEGF). The results showed that fewer platelets and thrombi were observed on the surface of the PEGDA-MPC-DHVs@VEGF. Additionally, the PEGDA-MPC-DHVs@VEGF exhibited excellent collagen stability, biocompatibility and re-endothelialization potential. Moreover, less calcification deposition and a lower immune response were observed in the PEGDA-MPC-DHVs@VEGF compared to the glutaraldehyde-crosslinked DHVs (Glu-DHVs) after subcutaneous implantation in rats for 30 days. These studies demonstrated that the strategy of zwitterionic hydrogels loaded with VEGF may be an effective approach to improving the biocompatibility, anti-calcification and re-endothelialization of bioprosthetic heart valves.

All-Polymeric Electrode Based on PEDOT:PSS for In Vivo Neural Recording.

One of the significant challenges today in the brain–machine interfaces that use invasive methods is the stability of the chronic record. In recent years, polymer-based electrodes have gained notoriety for achieving mechanical strength values close to that of brain tissue, promoting a lower immune response to the implant. In this work, we fabricated fully polymeric electrodes based on PEDOT:PSS for neural recording in Wistar rats. We characterized the electrical properties and both in vitro and in vivo functionality of the electrodes. Additionally, we employed histological processing and microscopical visualization to evaluate the tecidual immune response at 7, 14, and 21 days post-implant. Electrodes with 400-micrometer channels showed a 12 dB signal-to-noise ratio. Local field potentials were characterized under two conditions: anesthetized and free-moving. There was a proliferation of microglia at the tissue–electrode interface in the early days, though there was a decrease after 14 days. Astrocytes also migrated to the interface, but there was not continuous recruitment of these cells in the tissue; there was inflammatory stability by day 21. The signal was not affected by this inflammatory action, demonstrating that fully polymeric electrodes can be an alternative means to prolong the valuable time of neural recordings.