Potent T cell Responses Induced by Single DNA Vaccine Boosted with Recombinant Vaccinia Vaccine

Plasmid DNA, an effective vaccine vector, can induce both cellular and humoral immune responses. However, plasmid DNA raises issues concerning potential genomic integration after injection. This issue should be considered in preclinical studies. Tiantan vaccinia virus (TV) has been most widely utilized in eradicating smallpox in China. This virus has also been considered as a successful vaccine vector against a few infectious diseases. Potent T cell responses through T-cell receptor (TCR) could be induced by three injections of the DNA prime vaccine followed by a single injection of recombinant vaccinia vaccine. To develop a safer immunization strategy, a single DNA prime followed by a single recombinant Tiantan vaccinia (rTV) AIDS vaccine was used to immunize mice. Our data demonstrated that one DNA prime/rTV boost regimen induced mature TCR activation with high functional avidity, preferential T cell Vβ receptor usage and high sensitivity to anti-CD3 antibody stimulation. No differences in T cell responses were observed among one, two or three DNA prime/rTV boost regimens. This study shows that one DNA prime/rTV boost regimen is sufficient to induce potent T cell responses against HIV.

The Drug-carrier Interactions, Release Behaviors and Cell Responses of Hydroxyapaptite Containing Several Chinese Medicines

The present work shows drug-carrier interactions, release behaviors and cell responses of hydroxyapatite （HA） containing salvianolic acid B （Sal B）, astragalus polysaecharide （APS）, and naringin. X-ray diffraction （XRD） showed that the crystallinity and crystal size of HA decreased significantly when Sal B was added （p〈0.05）. Transmission electron microscope （TEM） confirmed that the nano-acicular crystals of HA containing Sal B were the most fine among all specimens. It was conjectured that Sal B preferentially adsorbed on the positively charged surface of HA crystals to inhibit their growth. In vitro release of HA containing Chinese medicines followed the first-order equation. The drug-carrier affinity between HA and Sal B might have prolonged the release of Sal B. The proliferation and differentiation of osteoblasts were promoted by Chinese medicines containing HA in the time and dosage dependent manner. The osteoblasts displayed a polygonal morphology with cell-cell junctions in all cases. It is suggested that the contained Chinese medicines would promote the activities of the osteoblasts.

SARS-CoV-2-specific T cell responses wane profoundly in convalescent individuals 10 months after primary infection

A key question in the coronavirus disease 2019(COVID-19)pandemic is the duration of specific T cell responses against the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)post primary infection,which is difficult to address due to the large-scale COVID-19 vaccination and re-exposure to the virus.Here,we conducted an analysis of the long-term SARS-CoV-2-specific T cell responses in a unique cohort of convalescent individuals(CIs)that were among the first to be infected worldwide and without any possible antigen re-exposure since then.The magnitude and breadth of SARS-CoV-2-specific T cell responses correlated inversely with the time that had elapsed from disease onset and the age of those CIs.The mean magnitude of SARS-CoV-2-specific CD4 and CD8 T cell responses decreased about 82%and 76%,respectively,over the time period of ten months after infection.Accordingly,the longitudinal analysis also demonstrated that SARS-CoV-2-specific T cell responses waned significantly in 75%of CIs during the follow-up.Collectively,we provide a comprehensive characterization of the long-term memory T cell response in CIs,suggesting that robust SARS-CoV-2-specific T cell immunity post primary infection may be less durable than previously expected.

An adjusted ELISpot-based immunoassay for evaluation of SARS-CoV-2-specific T-cell responses

Like antibody evaluation,using an effective antigen‐specific T‐cell immunity assessment method in coronavirus disease 2019(COVID‐19)patients,survivors and vaccinees is crucial for understanding the immune persistence,prognosis assessment,and vaccine development for COVID‐19.This study evaluated an empirically adjusted enzyme‐linked immunospot assay for detecting severe acute respiratory syndrome coronavirus 2(SARS‐CoV‐2)‐specific T‐cell immunity in 175 peripheral blood samples from COVID‐19 convalescents and healthy individuals.Results of viral nucleic acid were used as the gold standard of infection confirmation.The SARS‐CoV‐2M peptide pool had higher sensitivity of 85%and specificity of 71%for the single peptide pool.For combined peptide pools,the parallel evaluation(at least one of the peptide pools is positive)of total peptide pools(S1&S2&M&N)had higher sensitivity(up to 93%),and the serial evaluation(all peptide pools are positive)of total peptide pools had higher specificity(up to 100%).The result of the serial evaluation was better than that of the parallel evaluation as a whole.The detection efficiency of M and N peptide pool serial evaluation appeared the highest,with a sensitivity of 80%and specificity of 93%.This T‐cell immunity detection assay introduced in this report can achieve high operability and applicability.Therefore,it can be an effective SARS‐CoV‐2‐specific cellular immune function evaluation method.

Subversion of cellular stress responses by poxviruses

Cellular stress responses are powerful mechanisms that prevent and cope with the accumulation of macromolecular damage in the cells and also boost host defenses against pathogens. Cells can initiate either protective or destructive stress responses depending, to a large extent, on the nature and duration of the stressing stimulus as well as the cell type. The productive replication of a virus within a given cell places inordinate stress on the metabolism machinery of the host and, to assure the continuity of its replication, many viruses have developed ways to modulate the cell stress responses. Poxviruses are among the viruses that have evolved a large number of strategies to manipulate host stress responses in order to control cell fate and enhance their replicative success. Remarkably, nearly every step of the stress responses that is mounted during infection can be targeted by virally encoded functions. The fine-tuned interactions between poxviruses and the host stress responses has aided virologists to understand specific aspects of viral replication; has helped cell biologists to evaluate the role of stress signaling in the uninfected cell; and has tipped immunologists on how these signals contribute to alert the cells against pathogen invasionand boost subsequent immune responses. This review discusses the diverse strategies that poxviruses use to subvert host cell stress responses.

Cytotoxic Responses and Apoptosis in Rat Kidney Epithelial Cells Exposed to Lead

The toxic effects of lead on normal rat kidney epithelial cells（NRK cells）may occur via various pathways.However,the role of intrinsic mitochondrial pathway in Lead-induced apoptosis in NRK cells has not been investigated.The purpose of our study was to investigate cytotoxic responses and cell apoptosis mediated by lead in NRK cells.

Preventive effects of Bifidobacterium lactis Probio-M8 on ovalbumin-induced food allergy in mice

Food allergy is a significant public health concern globally.Certain probiotics have been found to enhance food allergy by regulating immune-microbe interactions in animal models and patients.However,the effects of Bifidobacterium lactis Probio-M8 on food allergy have not been thoroughly investigated.The present study examined the anti-allergic properties of Probio-M8,particularly in relation to immune response and gut microbiota composition.Results demonstrate that oral administration of Probio-M8 effectively mitigated the allergy symptoms triggered by ovalbumin(OVA)by ameliorating the morphological damage in the jejunum,reducing OVA-specific IgE and histamine levels in the serum,and suppressing Th2 cytokines(interleukin(IL)4 and IL-13)while increasing Th1 cytokines(interferon(IFN)γ)and regulatory T(Treg)cytokines(IL-10 and transforming growth factor(TGF)β1)in the culture supernatants of splenic cells.Furthermore,Probio-M8 effectively altered the diversity and composition of gut microbiota,particularly the relative abundances of Akkermansia_muciniphila in OVA-induced mice.Compared to the OVA group,the Probio-M8 group showed a decrease in the relative abundance of Akkermansia_muciniphila.In conclusion,Probio-M8 demonstrates the potential to alleviate food allergy by regulating the Th1/Th2 response and modulating gut microbiota,thereby offering a novel therapeutic strategy for patients with food allergy.

Natural course of chronic hepatitis B is characterized by changing patterns of programmed death type-1 of CD8-positive T cells

AIM:To investigate if and how programmed death type-1(PD-1)expression affects the natural course of hepatitis B virus(HBV)infection. METHODS:Sixty-four patients in different natural stages of chronic HBV infection were enrolled in this study.PD-1 expression in total T cells was detected by flow cytometry.Levels of total CD8+T cell responses and proliferation in relation to PD-1 expression levels were analyzed with intracellular staining and PD-1/ PD-L1 blockage. RESULTS:The PD-1 expression in T cells was dynamically changed during the natural course of chronic HBV infection,did not significantly increase in the immune tolerance phase,and returned to normal in the inactive virus carrier stage.Blockage of the PD-1/PD-L1 pathway could not affect the T-cell response in the immune tolerance and inactive virus carrier stages of chronic HBV infection.However,it could significantly restore the T-cell response in the immune clearance stage of chronic HBV infection.Furthermore,the PD-1 expression level in T cells was associated with the alanine aminotransferase level during the immune clearance stage of chronic HBV infection. CONCLUSION:The PD-l/PD-L1 pathway plays a different role in T-cell response during the natural course of chronic HBV infection.

T cell immune response is correlated with fibrosis and inflammatory activity in hepatitis B cirrhotics

AIM： TO explore the relationship among interferon-γ （IFN-γ） activity, fibrogenesis, T cell immune responses and hepatic inflammatory activity. METHODS： Peripheral blood samples from a total of 43 hepatitis B cirrhotic patients （LC） and 19 healthy controls （NC） were collected to measure their serum levels of IFN-γ, interleukin-2 （IL-2）, soluble interleukin-2 receptor （sIL-2R）, interleukin-10 （IL-10） and three serological markers of fibrosis including hyaluronic acid （HA）, procollagen type III peptide （PIIIP）, and type iV collagen were measured using a double antibody sandwich ELISA. Also, serum total bilirubin （TB） and alanine aminotransferase （ALT） were measured by routine measures. RESULTS： The concentrations of serological markers of fibrosis in patients with active cirrhosis （ALC） were significantly higher than those in stationary liver cirrhosis （SLC） or NC groups. The levels of serological markers in HBeAg-positive patients were significantly higher than those in HBeAg-negative patients. In SLC and ALC patients, a negative linear correlation was found between IFN-γ levels and the serological markers of fibrosis. IFN-γ and IL-2 levels in the ALC group were significantly higher than those in the SLC and NC groups, but the statistical difference was not significant between the latter two. In contrast, IL-10 levels in the SLC group were significantly higher than that in the NC group, but no significant difference was found between SLC and ALC groups. The sIL-2R level was elevated gradually in all these groups, and the differences were significant. Positive linear correlations were seen between IFN-γ activity and ALT levels （r = 0.339, P 〈 0.05）, and IL-2 activity and TB levels （r = 0.517, P 〈 0.05）. sIL-2R expression was positively correlated with both ALT and TB levels （r = 0.324, 0.455, P 〈 0.05）, whereas there was no statistically significant correlation between IL-10 expression and serum ALT and TB levels （r = -0.102, -0.093, P 〉 0.05）. Finally, there was a positive correlation between IFN-γ and IL-2 levels. CONCLUSION： T cell immune responses are correlated with fibrosis and hepatic inflammatory activity and may play an important role in liver cirrhosis.

Immune Responses in Wild-type Mice Against Prion Proteins Induced Using a DNA Prime-Protein Boost Strategy

Objective To break immune tolerance to prion （PrP） proteins using DNA vaccines.Methods Four different human prion DNA vaccine candidates were constructed based on the pcDNA3.1 vector：PrP‐WT expressing wild‐type PrP,Ubiq‐PrP expressing PrP fused to ubiquitin,PrP‐LII expressing PrP fused to the lysosomal integral membrane protein type II lysosome‐targeting signal,and PrP‐ER expressing PrP locating the ER.Using a prime‐boost strategy,three‐doses of DNA vaccine were injected intramuscularly into Balb/c mice,followed by two doses of PrP protein.Two weeks after the last immunization,sera and spleens were collected and PrP‐specific humoral and cellular immune responses evaluated by ELISA and ELISPOT tests.Results Higher levels of serum PrP antibodies were detected in mice vaccinated using the strategy of DNA priming followed by protein boosting.Of these,WT‐PrP,Ubiq‐PrP,and PrP‐LII induced significantly higher humoral responses.ELISPOT tests showed markedly increased numbers of IFN‐γ‐secreting T cells in mice vaccinated using the strategy of DNA priming followed by protein boosting after stimulation with recombinant PrP23‐90 and PrP23‐231.PrP‐ER inducedthe strongest T‐cell response.Conclusion Prion vaccines can break tolerance to PrP proteins and induce PrP‐specific humoral and cellular immune responses.

Mechanical responses of the bio-nano interface: A molecular dynamics study of graphene-coated lipid membrane

Bio-nano interfaces between biological materials and functional nanodevices are of vital importance in relevant energy and information exchange processes, which thus demand an in-depth understanding. One of the critical issues from the application viewpoint is the stability of the bio-nano hybrid under mechanical perturbations. In this work we explore mechanical responses of the interface between lipid bilayer and graphene under hydrostatic coating provides remarkable resistance to the pressure or indentation loads, We find that graphene loads, and the intercalated water layer offers additional protection. These findings are discussed based on molecular dynamics simulation results that elucidate the molecular level mechanisms, which provide a basis for the rational design of bionanotechnology- enabled aoolications such as biomedical devices and nanotheraoeutics.

The HMGB1 signaling pathway activates the inflammatory response in Schwann cells

Schwann cells are not only myelinating cells, but also function as immune cells and express numerous innate pattern recognition receptors, including the Toll-like receptors. Injury to peripheral nerves activates an inflammatory response in Schwann cells. However, it is unclear whether specific endogenous damage-associated molecular pattern molecules are involved in the inflammatory response following nerve injury. In the present study, we demonstrate that a key damage-associated molecular pattern molecule, high mobility group box 1（HMGB1）, is upregulated following rat sciatic nerve axotomy, and we show colocalization of the protein with Schwann cells. HMGB1 alone could not enhance expression of Toll-like receptors or the receptor for advanced glycation end products（RAGE）, but was able to facilitate migration of Schwann cells. When Schwann cells were treated with HMGB1 together with lipopolysaccharide, the expression levels of Toll-like receptors and RAGE, as well as inflammatory cytokines were upregulated. Our novel findings demonstrate that the HMGB1 pathway activates the inflammatory response in Schwann cells following peripheral nerve injury.

HIV-Specific IL-2^+ and/or IFN-γ^+ CD8^+ T Cell Reponses during Chronic HIV-1 Infection in Former Blood Donors

Objective Conflicting data have been generated from previous studies to determine which kind of relationship exists between HIV-1 specific CD8 Tcell responses and HIV-1 viral load or CD4 count over the course of infection.In this study,153 HIV-1 infected LTNPs were enrolled to investigate the role of HIV-1 specific CD8 T-cell responses in chronic HIV-1 infection among HIV-1 infected former blood donors.Methods The patients were stratified into three groups according to CD4 count：CD4≥500 cells/μL;350 cells/μL≤CD4〈500 cells/μL;CD4〈350 cells/μL.PBMCs were isolated from the patients＇ anticoagulated blood samples.IL-2 and IFN-γ secretions of CD 8 T cells against 17 HIV-1 consensus B full peptide pools were analyzed by using ICS assay.Results An overall inverse correlation were observed between CD4 count and plasma viral load.Although no significant difference was observed during the comparisons of frequency/breadth of HIV-1 specific CD8 T cell responses,CD4 count stratification analysis showed that different correlation pattern existed in three strata：as for patients whose CD4 counts were less than 350 cells/μL,no significant correlations were identified between frequency/breadth of HIV-1 specific CD8 T cell responses and CD4 count/viral load;as for patients whose CD4 counts ranged from 350 cells /μL to 500 cells/μL,significant correlation was only observed between the response breadth of IL-2＋IFN-γ＋ CD8 T cells and CD4 count;however,as for patients whose CD4 counts were more than 500 cells/μL,direct correlations were identified between IL-2＋IFN-γ＋/IL-2＋/IFN-γ＋ CD8 T cells and viral load or CD4 count.Conclusions Universal consistent inverse correlation was only indentified between CD4 count and viral load.The relationship between HIV-1 specific CD8 T cell responses and CD4 count/viral load varied in different CD4 strata,which showed that better preserved CD4 T cells were correlated with better CD8 T cell functions.

Measurement for Spectral Response of Solar Cells

General Research Institute for Non-ferrous Metals in cooperation with Changchun Instituteof Optical and Fine Mechanics prepared an automatic measurement instrument for spectral re-sponse test of solar cells. This instrument having enough accuracy can measure at AM1.5 condi-tion. It meets the needs for measurement of spectral response for silicon, gallium arsenide solarcells.

FROM MOLECULAR RESPONSE TO CELL RESPONSE-Approaching the complexity of biological systems

I. THE COMPLEXITY OFBIOLOGICAL RESPONSESFor an organism, to be living or notdepends on its response to foreign matters.Facing the increasing amount and diversi-ty of chemicals, natural and synthetic, tounderstand the principles of the biologicalresponses becomes extremely importantin pursuing the way of rational utiliza-tion and governing the foreign matters.However, most biological responses aretoo complex to explore their nature. Forinstance, the risk to human beings andorganisms related to the application ofrare earths in agriculture, forestation, fish-ery and husbandry has been argued

Expression and significance of toll-like receptor 2,4 in peripheral blood mononuclear cells in patients with systemic inflammatory response syndrome

To explore changes of toll-like receptor (TLR) 2,4 in peripheral blood mononuclear cells (PBMC) in acute abdomen patients with systemic inflammatory response syndrome (SIRS) and their significance.Methods A clinical study was done on 103 patients of which 65 were with SIRS.The mRNA expression of TLR2,4 were detected by RT-PCR;the expression of TNF-α and IL-6 were observed by ELISA;the correlation between TLR2,4 mRNA,the level of TNF-α and IL-6,and the clinical course was evaluated.Results TLR2 mRNA ,TNF-α and IL-6 were upregulated markedly on the first day of hospitalization,then decreased gradually;TLR2 mRNA maintained on high level till the 5th day.The expression of TLR2,4 mRNA was positive correlated with the level of TNF-α and IL-6,and the length of stay.TLR2,4 mRNA expression increased in patients with multiple organ failure.Conclusion In actue abdomen patients with SIRS,the expression of TLR2,4 of PBMC increased markedly,indicating its improtant role in the pathogenesis of SIRS.4 refs,2 figs,2 tabs.

Tissue-resident memory T cells break tolerance to renal autoantigens and orchestrate immune-mediated nephritis

Immune-mediated nephritis is a leading cause of acute kidney injury and chronic kidney disease.While the role of B cells and antibodies has been extensively investigated in the past,the advent of immune-checkpoint inhibitors has led to a reappraisal of the role of T cells in renal immunology.However,it remains elusive how T cells with specificity for renal autoantigens are activated and participate in immune-mediated nephritis.Here,we followed the fate and function of pathogen-activated autoreactive CD8 T cells that are specific for a renal autoantigen.We demonstrate that recently activated splenic CD8 T cells developed a hybrid phenotype in the context of renal autoantigen cross-presentation,combining hallmarks of activation and T cell dysfunction.While circulating memory T cells rapidly disappeared,tissue-resident memory T cells emerged and persisted within the kidney,orchestrating immune-mediated nephritis.Notably,T cells infiltrating kidneys of patients with interstitial nephritis also expressed key markers of tissue residency.This study unveils how a tissue-specific immune response can dissociate from its systemic counterpart driving a compartmentalized immune response in the kidneys of mice and man.Consequently,targeting tissue-resident memory T cells emerges as a promising strategy to control immune-mediated kidney disease.

Immune responses to the expressed products of the CSP antigen gene of Plasmodi um falciparum southern China isolate FCC1/HN in Hela cell

Objective To construct a eukaryotic expression system with pcDNA3-PfCSP/Hela for the Circumsporozoite protein (CSP) gene of Plasmodium falciparum (P. falciparum), to observe the immune responses in BALB/c mice induced by the expressed proteins. Methods The recombinant plasmid pcDNA3-PfCSP was transformed into the Hela cell line. The expressed protein was isolated and analyzed by using SDS-PAGE and used for immunization of BALB/c mice by subcutaneous, intravenous, and intraperitoneal adminstration. Enzyme-linked immunosorbent assay(ELISA), Dot-ELISA, Western blot, T lymphocyte proliferation test, natural killer cell(NKC) activity assay, and CD4+ and CD8+ T cell detection were used for observation of humoral and cellular immune responses. Results Immune sera strongly reacted with the expressed protein, antibody titer was up to 1∶6400 as detected by ELISA. Western blot analysis revealed a specific band at 38.3?Kda. When the spleen cells of normal and immunized BALB/c mice were specifically stimulated with expressed protein, the optical densities were 0.12±0.03 and 0.34±0.04, respectively. The latter were significantly higher than the former (P<0.01). We used the MTT colorimetric assay to measure NKC activity of mice spleen. The results showed that the NKC activity of immunized BALB/c mice was remarkably higher than that of the controls (P<0.05). CD4+ and CD8+ T cells were detected by using monoclonal antibody immunofluorescence methods. The results showed that the percentage of CD4+ and CD8+ T cells of immunized group were significantly higher than that of control group (P<0.05).Conclusions The humoral and cell-mediated immune responses and elevated NKC activity to products made with a eukaryotic expression system could be specifically detected in BALB/c mice. These findings indicate that the expressed protein could enhance the immune function in mice.

Relationship between T-lymphocyte cytokine levels and sero-response to hepatitis B vaccines

AIM: To investigate the cellular defects by analyzing the (Th1/Th2) cytokine levels in vaccine responders and non-responders. METHODS: Peripheral blood mononuclear cell (PBMC) from responders and non-responders were stimulated with or with out recombinant HBsAg or PHA. Broad spectrum of cytokines viz (Th1) IFN-γ, IL-2, TNF-α, IL-12 and (Th2) IL-10, IL-4 were measured after in vitro stimulation with recombinant HBsAg and were compared with respective antibody titers. RESULTS: A significant decrease (P = 0.001) in Th1 and Th2 cytokines namely, IL-2, INF-γ, TNF-α and IL-10in non-responders was observed. The level of IL-4 was not significant between the three groups. Furthermore, despite a strong Th1 and Th2 cytokine response, the level of IL-12 was elevated in high-responders compared to other groups (P = 0.001) and demonstrated a positive correlation with anti-HBs titers and Th1 cytokine response. CONCLUSION: Our findings suggest that unrespon-siveness to recombinant hepatitis B vaccines (rHB) is multifactorial, including specific failure of antigen presentation or the lack of both T helper Th1 and Th2 response.