Mediators Of Cellular Immunity Research Articles

Studying Immunoreceptor Signaling in Human T Cells Using Electroporation of In Vitro Transcribed mRNA.

The recognition bestowed upon T lymphocytes as key mediators of cellular immunity has been further attested by recent successful clinical studies using genetically modified T cells. With an ever-growing interest in the application of T cells to treat human malignancies, studying the molecular mechanisms of T cell activation, signaling, and function has become imperative. This, therefore, calls for the development of new easy-to-use and accurate models to investigate the biological phenomena that begin at the synaptic levels of T cell and antigen interactions to the ultimate exhaustion and death of the T cell. Here, we describe an approach to transiently express a chimeric molecule on the cell surface that permits activation and expansion of T cells, thereby providing a model to study T cell signaling.

The Diagnostic Impact of C4d, CD68, and NF-κB Expression in the Differentiation Between Recurrent Hepatitis C and Acute Cellular Rejection After Liver Transplantation.

Liver transplantation is the selected treatment for patients with advanced liver disease and cirrhosis, mostly as a complication of hepatitis C virus (HCV). Recurrent HCV and acute cellular rejection (ACR) of the graft are the most common causes of graft failure. The distinction between the 2 conditions is essential because they are managed differently. In some cases, the clinical and histopathologic features may overlap between recurrent hepatitis C and ACR, making differentiation difficult. The aim of this study was to investigate the role of C4d, CD68, and nuclear factor kappa-B (NF-κB) in the differentiation between ACR and recurrent HCV in the post-liver-transplant biopsy using immunohistochemistry. C4d expression in endothelial cells of portal or central veins (P=0.001) and the number of macrophages highlighted by CD68 (P=0.02) were in favor of ACR, whereas NF-κB expression by hepatocytes was in favor of recurrent hepatitis C. Vascular injury demonstrated by endothelial expression of C4d and prominent macrophage infiltration identified by CD68 expression were the distinguishing criteria for ACR and representing humoral and cellular-mediated immunity as evoking factors for graft injury. The upregulation of NF-κB in the hepatocytes of recurrent hepatitis C could be an immune response to infection or it may be induced by HCV itself.

Induction of Protective Immunity against Toxoplasmosis in BALB/c Mice Vaccinated with Toxoplasma gondii Rhoptry-1.

Toxoplasma gondii is the causative agent for toxoplasmosis. The rhoptry protein 1 (ROP1) is secreted by rhoptry, an apical secretory organelle of the parasite. ROP1 plays an important role in host cell invasion. In this study, the efficacy of ROP1 as a vaccine candidate against toxoplasmosis was evaluated through intramuscular or subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Briefly, a recombinant DNA plasmid (pVAX1-GFP-ROP1) was expressed in CHO cells while expression of recombinant ROP1 protein (rROP1) was carried out in Escherichia coli expression system. Immunization study involved injection of the recombinant pVAX1-ROP1 and purified rROP1 into different group of mice. Empty vector and PBS served as two different types of negative controls. Results obtained demonstrated that ROP1 is an immunogenic antigen that induced humoral immune response whereby detection of a protein band with expected size of 43 kDa was observed against vaccinated mice sera through western blot analysis. ROP1 antigen was shown to elicit cellular-mediated immunity as well whereby stimulated splenocytes with total lysate antigen (TLA) and rROP1 from pVAX1-ROP1 and rROP1-immunized mice, respectively, readily proliferated and secreted large amount of IFN-γ (712 ± 28.1 pg/ml and 1457 ± 31.19 pg/ml, respectively) and relatively low IL-4 level (94 ± 14.5 pg/ml and 186 ± 14.17 pg/ml, respectively). These phenomena suggested that Th1-favored immunity was being induced. Vaccination with ROP1 antigen was able to provide partial protection in the vaccinated mice against lethal challenge with virulent RH strain of tachyzoites. These findings proposed that the ROP1 antigen is a potential candidate for the development of vaccine against toxoplasmosis.

Evaluation of Immunoprotection Conferred by the Subunit Vaccines of GRA2 and GRA5 against Acute Toxoplasmosis in BALB/c Mice.

Toxoplasmosis is a foodborne disease caused by Toxoplasma gondii, an obligate intracellular parasite. Severe symptoms occur in the immunocompromised patients and pregnant women leading to fatality and abortions respectively. Vaccination development is essential to control the disease. The T. gondii dense granule antigen 2 and 5 (GRA2 and GRA5) have been targeted in this study because these proteins are essential to the development of parasitophorous vacuole (PV), a specialized compartment formed within the infected host cell. PV is resistance to host cell endosomes and lysosomes thereby protecting the invaded parasite. Recombinant dense granular proteins, GRA2 (rGRA2) and GRA5 (rGRA5) were cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of these purified antigens as subunit vaccine candidates against toxoplasmosis were evaluated through subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Results obtained demonstrated that rGRA2 and rGRA5 elicited humoral and cellular-mediated immunity in the mice. High level of IgG antibody was produced with the isotype IgG2a/IgG1 ratio of ≈0.87 (p < 0.001). Significant increase (p < 0.05) in the level of four cytokines (IFN-γ, IL-2, IL-4, and IL-10) was obtained. The antibody and cytokine results suggest that a mix mode of Th1/Th2-immunity was elicited with predominant Th1-immune response inducing partial protection against T. gondii acute infection in BALB/c mice. Our findings indicated that both GRA2 and GRA5 are potential candidates for vaccine development against T. gondii acute infection.

Immune Checkpoint Inhibitors and Prostate Cancer: A New Frontier?

Despite recent advances in the treatment of metastatic castration-resistant prostate cancer (mCRPC), agents that provide durable disease control and long-term survival are still needed. It is a fact that a tumor-induced immunosuppressive status (mediated by aberrant activation of inhibitory immune checkpoint pathways as a mechanism to evade host immune surveillance) plays a crucial role in the pathogenesis of cancer, including prostate cancer (PC), making CRPC patients suitable candidates for immunotherapy. Therefore, growing interest of anticancer research aims at blocking immune checkpoints (mainly targeting CTLA-4 and PD1/PD-L1 pathways) to restore and enhance cellular-mediated antitumor immunity and achieve durable tumor regression. In this review, we describe the current knowledge regarding the role of immune checkpoints in mediating PC progression, focusing on CTLA-4 and PD1 pathways. We also provide current clinical data available, an update on ongoing trials of immune checkpoint inhibitors in PC. Finally, we discuss the necessity to identify prognostic and predictive biomarkers of immune activity, and we analyze new immune checkpoints with a role as promising targets for PC therapy.

HIV Envelope Trimer Specific Immune Response Is Influenced by Different Adjuvant Formulations and Heterologous Prime-Boost.

The development of a preventive vaccine against human immunodeficiency virus (HIV-1) infection is the most efficient method to control the epidemic. The ultimate goal is to develop a vaccine able to induce specific neutralizing, non-neutralizing antibodies and cellular mediated immunity (CMI). Humoral and CMI responses can be directed to glycoproteins that are normally presented as a trimeric spike on the virus surface (gp140). Despite safer, subunit vaccines are normally less immunogenic/effective and need to be delivered together with an adjuvant. The choice of a suitable adjuvant can induce effective humoral and CMI that utterly lead to full protection against disease. In this report, we established a hierarchy of adjuvant potency on humoral and CMI when admixed with the recombinant HIV gp140 trimer. We show that vaccination with gp140 in the presence of different adjuvants can induce high-affinity antibodies, follicular helper T cells and germinal center B cells. The data show that poly (I:C) is the most potent adjuvant to induce specific CMI responses evidenced by IFN-γ production and CD4+/CD8+ T cell proliferation. Furthermore, we demonstrate that combining some adjuvants like MPL plus Alum and MPL plus MDP exert additive effects that impact on the magnitude and quality of humoral responses while mixing MDP with poly (I:C) or with R848 had no impact on total IgG titers but highly impact IgG subclass. In addition, heterologous DNA prime- protein boost yielded higher IgG titers when compare to DNA alone and improved the quality of humoral response when compare to protein immunization as evidenced by IgG1/IgG2a ratio. The results presented in this paper highlight the importance of selecting the correct adjuvant-antigen combination to potentiate desired cells for optimal stimulation.

Soy Isoflavones Promote Radioprotection of Normal Lung Tissue by Inhibition of Radiation-Induced Activation of Macrophages and Neutrophils

Radiation therapy for lung cancer is limited by toxicity to normal lung tissue that results from an inflammatory process, leading to pneumonitis and fibrosis. Soy isoflavones mitigate inflammatory infiltrates and radiation-induced lung injury, but the cellular immune mediators involved in the radioprotective effect are unknown. Mice received a single dose of 10 Gy radiation delivered to the lungs and daily oral treatment of soy isoflavones. At different time points, mice were either processed to harvest bronchoalveolar lavage fluid for differential cell counting and lungs for flow cytometry or immunohistochemistry studies. Combined soy and radiation led to a reduction in infiltration and activation of alveolar macrophages and neutrophils in both the bronchoalveolar and lung parenchyma compartments. Soy treatment protected F4/80CD11c interstitial macrophages, which are known to play an immunoregulatory role and are decreased by radiation. Furthermore, soy isoflavones reduced the levels of nitric oxide synthase 2 expression while increasing arginase-1 expression after radiation, suggesting a switch from proinflammatory M1 macrophage to an anti-inflammatory M2 macrophage phenotype. Soy also prevented the influx of activated neutrophils in lung caused by radiation. Soy isoflavones inhibit the infiltration and activation of macrophages and neutrophils induced by radiation in lungs. Soy isoflavones-mediated modulation of macrophage and neutrophil responses to radiation may contribute to a mechanism of resolution of radiation-induced chronic inflammation leading to radioprotection of lung tissue.

Integrating between-host transmission and within-host immunity to analyze the impact of varicella vaccination on zoster.

Varicella-zoster virus (VZV) causes chickenpox and reactivation of latent VZV causes herpes zoster (HZ). VZV reactivation is subject to the opposing mechanisms of declining and boosted VZV-specific cellular mediated immunity (CMI). A reduction in exogenous re-exposure 'opportunities' through universal chickenpox vaccination could therefore lead to an increase in HZ incidence. We present the first individual-based model that integrates within-host data on VZV-CMI and between-host transmission data to simulate HZ incidence. This model allows estimating currently unknown pivotal biomedical parameters, including the duration of exogenous boosting at 2 years, with a peak threefold to fourfold increase of VZV-CMI; the VZV weekly reactivation probability at 5% and VZV subclinical reactivation having no effect on VZV-CMI. A 100% effective chickenpox vaccine given to 1 year olds would cause a 1.75 times peak increase in HZ 31 years after implementation. This increase is predicted to occur mainly in younger age groups than is currently assumed.

Molecular basis of carcinogenesis in diabetic patients (review).

The most important molecular mechanisms promoting carcinogenesis in patients with diabetes mellitus (DM) include oxidative stress, excessive generation of free radicals and nitrous oxide, damage to cellular membranes and DNA, overproduction of lactate, overabundance of protein glycosylation storage products, overexpression of pathological enzyme isoforms, and leakage of cytochromes from organelles. Additionally, dysfunctional signal transduction pathways, especially in pathways involving phosphoinositide 3‑kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt, RAS/Raf/ERK, and mammalian target of rapamycin (mTOR), have been implicated in malignant transformation and progression. Obesity and metabolic disorders, such as DM, may contribute to a dysfunctional immune system with a suppressed immune response by inducing a chronic inflammatory state, abnormal humoral and cellular mediated immunity, and lower counts and activity levels of natural killer (NK) cells and natural killer T cells (NKT cells). Recent advances in molecular biology will allow for better understanding of abnormal cellular pathways, as well as elucidating how metabolic disorders contribute to oncogenesis. Knowledge gained through these studies may lead to more efficacious oncologic therapies.

Evaluation of Humoral Immunity to Mycobacterium tuberculosis-Specific Antigens for Correlation with Clinical Status and Effective Vaccine Development.

Although tuberculosis remains a major global health problem, Bacille Calmette-Guérin (BCG) is the only available vaccine. However, BCG has limited applications, and a more effective vaccine is needed. Cellular mediated immunity (CMI) is thought to be the most important immune response for protection against Mycobacterium tuberculosis (Mtb). However, the recent failure of a clinical trial for a booster BCG vaccine and increasing evidence of antibody-mediated immunity prompted us to evaluate humoral immunity to Mtb-specific antigens. Using Enzyme-Linked ImmunoSpot and Enzyme-Linked ImmunoSorbent Assays, we observed less correlation of both CMI and IgG titers with patient clinical status, including serum concentration of C reactive protein. However, IgA titers against Mtb were significantly correlated with clinical status, suggesting that specific IgA antibodies protect against Mtb proliferation. In addition, in some cases, IgA antibody titers were significantly associated with the serum concentration of total albumin, which supports the idea that humoral immunity can be influenced by the nutritional status. Based on these observations, we propose that the induction of humoral immunity should be included as an option in TB vaccine development strategies.

Immunologically mediated oral diseases.

Immune mediated diseases of oral cavity are uncommon. The lesions may be self-limiting and undergo remission spontaneously. Among the immune mediated oral lesions the most important are lichen planus, pemphigus, erythema multiformi, epidermolysis bullosa, systemic lupus erythematosis. Cellular and humoral mediated immunity play a major role directed against epithelial and connective tissue in chronic and recurrent patterns. Confirmatory diagnosis can be made by biopsy, direct and indirect immunoflouresence, immune precipitation and immunoblotting. Therapeutic agents should be selected after thorough evaluation of immune status through a variety of tests and after determining any aggravating or provoking factors. Early and appropriate diagnosis is important for proper treatment planning contributing to better prognosis and better quality of life of patient.

Toxoplasma gondii Exposure and the Risk of Schizophrenia.

Background:Schizophrenia is a major psychiatric disorder with a deeply destructive pathophysiology. There are evidences to indicate that infectious agents such as Toxoplasma gondii may play some roles in etiology of the disorder.Objectives:The current study aimed to determine the association between T. gondii exposure and the risk of schizophrenia.Materials and Methods:T. gondii IgG antibodies of 100 patients with schizophrenia as well as 200 healthy volunteers were assessed. The subjects also completed demographic questionnaires. Data was analyzed using the chi-square and Fisher exact tests.Results:The analyses confirmed the significant differences between healthy women and ones with schizophrenia (P = 0.001) as well as between males and females with schizophrenia (P = 0.009) in IgG positivity.Conclusions:The present study supported the contamination with T. gondii as a risk factor for schizophrenia just in women.

Effect of soy isoflavones on some immunological parameters in ovariectomized female rats.

Soy Isoflavones have estrogenic activity and arewidely used in human and animal diets. They have many useful activities invitro and in vivo. However, Evidence is emerging that dietary isoflavones havean effect on immune system. The objectives of this study was to determine theeffect of soy isoflavones on some cellular immunological parameters includingthrough estimation of their effect on daily food intake, daily body weightgain, splenic and thymic weights, total and differential leukocytic count (TLC& DLC), IL-6 and histopathology of both thymus and spleen. A total of 30ovariectomized female Albino rats were divided into three groups (10 females /group). Control group (C) received phytoestrogen-free casein-based diet, lowsoy phytoestrogens group (LF) received low phytoestrogens diet containing (7%soybeans) and high soy phytoestrogens (HF) group received high phytoestrogensdiet containing (26% soybeans) for 30 days. The results revealed that dietaryphytoestrogens didn’t alter daily food intake while reduced daily body weightgain significantly (P<0.05) in HF group than LF and control group. Splenicrelative weight showed non-significant difference between groups while Thymusrelative weight was significantly (P<0.05) reduced in LF and HF groups thancontrol in a dose depending manner. Total leukocytic count was significantly(P<0.05) increased in LF and HF groups than control while DLC showednon-significant difference among groups. Inteleukin-6 was significantly(P<0.05) reduced in both treated groups than control. The histopathologicalstudies of treated groups showed decreased white pulp (WP) area and cellularitywith reduced number of lymphocytes especially in HF group with depletion inmedullary area of thymus in LF group and apoptotic lymphocytes in HF group.These findings show that dietary phytoestrogens interfere with cellular mediatedimmunity in ovariectomized female rats, so theycould alleviate autoimmune diseases manifestations.

Study of Antigenicity and Immunogenicity Gra1 Protein from Toxoplasma gondii

Toxoplasmosis is known as zoonotic disease caused by Toxoplasma gondii infection. This microorganism has ability to evade immune system by forming parasitophorus vacuole (PV) formed through the phagosome vacuole modification by secreting dense granule protein (GRA). Among GRAs protein, GRA1 was selected as candidate for vaccine development. However, it remains controvercial whether the protein has adequate antigenicity and strong immunogenicity which are suitable for vaccine candidate. Some researcher reported that DNA vaccine of GRA1 was able to induce cellular mediated immunity and proinflamatoric humoral immunity. In fact, another study demonstrated that GRA1 protein was only antigenic based on their molecular weight and bioinformatic analysis.The other studies also showed that GRA1 was considered as weak immunogen based on bioinformatic studies. The ability of GRA1 protein to stimulate immune responses, both humoral and cellular mediated immunity were seemly caused by adjuvant. Key words: Toxoplasma gondii , GRA1, cellular mediated immunity, humoral immunity

Immunological responses and epitope mapping by tuberculosis-associated antigens within the RD1 region in Japanese patients.

Tuberculosis remains a major global health problem worldwide, and hence there is a need for novel vaccines that better induce cellular-mediated immunity (CMI). In search of a better vaccine target, the QuantiFERON-TB Gold In-Tube Test (QFT-GIT) and the interferon-γ ELISPOT assay (ELISPOT) were used to compare the magnitude of CMI in patients. Results of the ELISPOT assay led to the discovery of specific epitopes within the early secreted antigenic target 6 kDa (ESAT-6) and culture filtrate protein 10 kDa (CFP-10) proteins. Both peptides showed a strong association with several HLA class II DRB1 molecules in the Japanese population. Using ESAT-6-specific HLA class II tetramers, we determined that the expression of ESAT-6-specific CD4+ lymphocytes was significantly decreased in treated patients compared with active patients. In addition, programmed death-1 (PD-1)/killer cell lectin-like receptor G1 (KLRG-1) double positive cells were found only in treated patients and not in those with active TB. These data could provide clues for the development of novel tuberculosis vaccines.

Protective role of adenylate cyclase in the context of a live pertussis vaccine candidate

Despite high vaccination coverage, pertussis remains an important respiratory infectious disease and the least-controlled vaccine-preventable infectious disease in children. Natural infection with Bordetella pertussis is known to induce strong and long-lasting immunity that wanes later than vaccine-mediated immunity. Therefore, a live attenuated B. pertussis vaccine, named BPZE1, has been developed and has recently completed a phase I clinical trial in adult human volunteers. In this study, we investigated the contribution of adenylate cyclase (CyaA) in BPZE1-mediated protection against pertussis. A CyaA-deficient BPZE1 mutant was thus constructed. Absence of CyaA did not compromise the adherence properties of the bacteria onto mammalian cells. However, the CyaA-deficient mutant displayed a slight impairment in the ability to survive within macrophages compared to the parental BPZE1 strain. In vivo, whereas the protective efficacy of the CyaA-deficient mutant was comparable to the parental strain at a vaccine dose of 5 × 105 colony forming units (CFU), it was significantly impaired at a vaccine dose of 5 × 103 CFU. This impairment correlated with impaired lung colonization ability, and impaired IFN-γ production in the animal immunized with the CyaA-deficient BPZE1 mutant while the pertussis-specific antibody profile and Th17 response were comparable to those observed in BPZE1-immunized mice. Our findings thus support a role of CyaA in BPZE1-mediated protection through induction of cellular mediated immunity.

SPECIFIC IMMUNE PROTECTION TO KLEBSIELLA PNEUMONIAE AND ENTEROCOCCUS FAECALIS IN THE CHRONIC PROSTATITIS SUFFERERS

Microbiological investigation of samples in the chronic prostatitis (CP) sufferers showed that isolation opportunistic bacteria: Enterococcus faecalis and Klebsiella pneumoniae from tested samples of expressed prostatic secretions (EPS) are the cause of inflammation and aggravation of prostate in men. Except microbiological culture isolation it was investigated condition immune system. Such parameters of cellular mediated immunity as CD3 + ; CD4 + ; CD8 + ; CD16 + ; CD19 + ; PAN (phagocytic activity of neutrophils). Humoral mediated immunity by concentration of immunoglobulin classes: А, G, М in serum as well as determined. Such complex bacteriological and immunological investigation enables us to gain a better understanding of the reason and mechanism of inflammation. It was indicated that parameters of cellular mediated immunity during inflammation decrease, however, IgA concentration increases and concentration of IgM decrease. After specific immune protection parameters of immue system including cellular mediated immunity and humoral immunity normalized. Such detailed investigation of immune system gives an ability to specify total condition the immune system and it`s reserves for specific immune protection of mucosal from such opportunistic bacteria as: Enterococcus faecalis and Klebsiella pneumoniae . Key words: phagocytic activity of neutrophils, immunoglobulin classes, Klebsiella pneumoniae, Enterococcus faecalis, immune system.

Induction of Broadly Neutralising HCV Antibodies in Mice by Integration-Deficient Lentiviral Vector-Based Pseudotyped Particles

IntroductionIntegration-deficient lentiviral vectors (IDLVs) are a promising platform for immunisation to elicit both humoral immunity and cellular mediated immunity (CMI). Here, we compared the specific immunity in mice immunised via different regimens (homologous and cocktail) with IDLV-based HCV pseudoparticles (HCVpps) carrying pseudotyped glycoproteins E1E2 and bearing the HCV NS3 gene. Humoral and cell-mediated immune responses were also evaluated after IDLV-HCVpp immunisation combined with heterologous rAd5-CE1E2 priming protocols. Sera from the mice effectively elicited anti-E1, -E2, and -NS3 antibody responses, and neutralised various HCVpp subtypes (1a, 1b, 2a, 3a and 5a). No significant CMI was detected in the groups immunised with IDLV-based HCVpps. In contrast, the combination of rAd5-CE1E2 priming and IDLV-based HCVpp boosting induced significant CMI against multiple antigens (E1, E2, and NS3).ConclusionIDLV-based HCVpps are a promising vaccination platform and the combination of rAd5-CE1E2 and IDLV-based HCVpp prime-boost strategy should be further explored for the development of a cross-protective HCV vaccine.

Innate Immune Activation Enhances HIV Acquisition in Women, Diminishing the Effectiveness of Tenofovir Microbicide Gel

The antiretroviral agent, tenofovir, formulated as a vaginal microbicide gel, reduces human immunodeficiency virus (HIV) acquisition by 39% in women. This study assessed the role of preexisting immune activation in HIV acquisition in women from the CAPRISA 004 trial, to identify potential strategies to increase the effectiveness of tenofovir gel. Systemic cytokine and cellular immune mediators (platelets and natural killer [NK] cells) were assessed in women at high risk for HIV assigned to either tenofovir or placebo gel in the CAPRISA 004 trial. Notwithstanding tenofovir gel use, women who acquired HIV had significantly higher systemic innate immune activation prior to infection than women who remained uninfected. Activation of both soluble (cytokine) and cellular (NK cells) immune mediators were associated with HIV acquisition, individually or in combination. Hence, an innate immune activation suppressant could be added to tenofovir gel as a potential combination gel strategy in developing the next generation of higher efficacy antiretroviral microbicides.

Interaction Between Pediatric HIV Infection and Measles

Infections by measles virus and by HIV cause a state of immunodeficiency in the host. While measles virus leads to a transient immunodeficiency with depression of cellular mediated immunity, natural HIV infection leads to a progressive immunodeficiency of both humoral and cellular immunity. This review will focus on the interaction between HIV and measles virus in pediatric patients. Different scenarios of virus interaction will be dissected and their implications for a practical approach in terms of the individual patient and strategies to eliminate measles virus will be discussed.