Lymphocyte-dependent Immune Response Research Articles

PKHB1 peptide induces antiviral effects through induction of immunogenic cell death in herpes simplex keratitis.

Herpes simplex keratitis (HSK) is a severe, infectious corneal disease caused by herpes simplex virus type 1 (HSV-1) infection. The increasing prevalence of acyclovir resistance, the side effects of hormonal drugs, and the ease of recurrence after surgery have made it crucial to develop new methods of treating HSK. HSV-1 evades the host immune response through various mechanisms. Therefore, we explored the role of the immunogenic cell death inducer PKHB1 peptide in HSK. After subconjunctival injection of PKHB1 peptide, we observed the ocular surface lesions and survival of HSK mice and detected the virus levels in tear fluid, corneas, and trigeminal ganglions. We found that PKHB1 peptide reduced HSV-1 levels in the eye and alleviated the severity of HSK. Moreover, it increased the number of corneal infiltrating antigen-presenting cells (APCs), such as macrophages and dendritic cells, and CD8+ T cells in ocular draining lymph nodes. We further observed that PKHB1 peptide promoted the exposure of calreticulin, as well as the release of ATP and high-mobility group box 1 in HSV-1-infected cells in vitro. Our findings suggested that PKHB1 peptide promoted the recruitment and maturation of APCs by inducing the release of large amounts of damage-associated molecular patterns from infected cells. APCs then phagocytized antigenic materials and translocated to the lymph nodes, triggering a cytotoxic T lymphocyte-dependent immune response that ultimately alleviated HSK.

Dormant Tumor Cell Vaccination: A Mathematical Model of Immunological Dormancy in Triple-Negative Breast Cancer.

Simple SummaryTriple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, particularly affecting young women. Chemotherapy is the main choice for the treatment of these patients. It has been shown that some chemotherapies induce immunogenic cell death and elicit an adaptive cytotoxic T cell immune response through the activation of the type I interferon pathway. We made an evolutionary mathematical model based on the recently reported in vivo induction of immunological tumor dormancy of a murine TNBC cell line upon in vitro treatment with chemotherapy. Our model replicates the previously obtained experimental results and predicts a prophylactic and therapeutic vaccination effect by injecting dormant cells with active type I interferon signaling, before or after challenge with the aggressive parental tumor cells, respectively. These results show the potential of a dormant tumor cell-based therapy inducing an adaptive immune response, suppressing tumor growth.Triple-negative breast cancer (TNBC) is a molecular subtype of breast malignancy with a poor clinical prognosis. There is growing evidence that some chemotherapeutic agents induce an adaptive anti-tumor immune response. This reaction has been proposed to maintain the equilibrium phase of the immunoediting process and to control tumor growth by immunological cancer dormancy. We recently reported a model of immunological breast cancer dormancy based on the murine 4T1 TNBC model. Treatment of 4T1 cells in vitro with high-dose chemotherapy activated the type I interferon (type I IFN) signaling pathway, causing a switch from immunosuppressive to cytotoxic T lymphocyte-dependent immune response in vivo, resulting in sustained dormancy. Here, we developed a deterministic mathematical model based on the assumption that two cell subpopulations exist within the treated tumor: one population with high type I IFN signaling and immunogenicity and lower growth rate; the other population with low type I IFN signaling and immunogenicity and higher growth rate. The model reproduced cancer dormancy, elimination, and immune-escape in agreement with our previously reported experimental data. It predicted that the injection of dormant tumor cells with active type I IFN signaling results in complete growth control of the aggressive parental cancer cells injected at a later time point, but also of an already established aggressive tumor. Taken together, our results indicate that a dormant cell population can suppress the growth of an aggressive counterpart by eliciting a cytotoxic T lymphocyte-dependent immune response.

THE INFLUENCE OF PATHOGENETIC THERAPY ON THE LEVER OF CYTOKINES IN PATIENTS WITH ACUTE BRUCELLOSIS

The purpose of the study was to determine the level of proinflammatory cytokines: IL-12, IL-8 and IFN, neopterin and lipopolysaccharide-binding protein in the serum of patients with acute brucellosis before and after antibiotic therapy. The clinical data from 32 patients with laboratory-confirmed diagnosis acute brucellosis admitted to the diagnosis, treatment and examination of occupational diseases brucellosis GBUZ SC City Clinical Hospital No. 2, the city of Stavropol were used in the study. The concentrations IL-12, IL-8, IFN cytokines and acute-phase proteins in serum was determined by ELISA. In the acute phase of brucellosis infection (before treatment) had high levels of pro-inflammatory cytokines IL-8 and IFN, but despite holding a course of antibiotic treatment in the serum of patients with preserved high levels of IL-8, indicative of active inflammation in the absence of clinical manifestations. IL-12 level, a key cytokine in the initiation of lymphocyte-dependent immune response was lower than in the control group. Evaluation of the cytokine status (IL-8, IL-12, IL-18) and proteins of acute inflammation phase (neopterin and lipopolysaccharide-binding protein) will provide valuable information for monitoring the effect of pharmacotherapy of acute brucellosis. Indicators of lipopolysaccharide-binding protein and neopterin in the serum of patients with brucellosis should be considered as a marker of inflammatory activity and as a predictor of outcome of acute brucellosis.

17β-Estradiol influences in vitro response of aged rat splenic conventional dendritic cells to TLR4 and TLR7/8 agonists in an agonist specific manner.

This study was undertaken considering that, despite the broad use of the unopposed estrogen replacement therapy in elderly women, data on estrogen influence on the functional capacity of dendritic cells (DCs), and consequently immune response are limited. We examined the influence of 17β-estradiol on phenotype, cytokine secretory profile, and allostimulatory and polarizing capacity of splenic (OX62+) conventional DCs from 26-month-old (aged) Albino Oxford rats matured in vitro in the presence of LPS, a TLR4 agonist, and R848, a TLR7/8 agonist. In the presence of 17β-estradiol, DCs from aged rats exhibited an impaired ability to mature upon stimulation with LPS, as shown by the lower surface density of MHC II and costimulatory CD80 and CD86 molecules. 17β-Estradiol alone enhanced CD40 expression in OX62+ DCs without affecting the expression of other costimulatory molecules, thereby confirming that the expression of this molecule is regulated independently from the regulation of other costimulatory molecules. However, although R848 upregulated the expression of MHC II and CD80 and CD40 costimulatory molecules on DCs, 17β-estradiol diminished the effect of this TLR agonist only on MHC II expression. In conjunction, the previous findings suggest that LPS and R848 elicit changes in the expression of costimulatory molecules via triggering differential intracellular signaling pathways. Furthermore, 17β-estradiol diminished the stimulatory influence of both LPS- and R848-matured OX62+ DCs on allogeneic CD4+ T lymphocyte proliferation in a mixed lymphocyte reaction (MLR). Moreover, as shown in MLR, the exposure to 17β-estradiol during LPS- and R848-induced maturation diminished Th1- and enhanced Th17-driving capacity and reduced Th1-driving capacity of OX62+ DCs, respectively. This suggests that LPS and R848 affect not only the surface phenotype, but also functional characteristics of OX62+ DCs triggering distinct intracellular signaling pathways. Collectively, the findings indicate that estrogen directly acting on OX62+ DCs, may affect CD4+ lymphocyte-dependent immune response in aged female rats.

Clinical implications of fibroblast activation protein-α in non-small cell lung cancer after curative resection: a new predictor for prognosis

Fibroblast activation protein-α (FAP-α), which is a serine protease specially expressed on the surface of the cancer stromal cells, plays an important role in the progression and prognosis in diverse malignancies. However, the role of FAP-α in non-small cell lung cancer (NSCLC) is still unknown. We enrolled 59 NSCLC patients who received complete resection. Sections of paraffin-embedded primary NSCLC specimens of all the patients were stained with antibody directed against FAP-α. Overall, percentage (Grade 0-3) and intensity (0-3+) of stromal FAP-α staining of the tumor were assessed. FAP-α was detected in >76% of the specimens examined, and its high expression seemed to be correlated with poor tumor differentiation (P=0.06). Furthermore, both increased FAP-α staining percentage and intensity were associated with worse overall survival of the patients (percentage, P=0.0087; intensity, P=0.05). Higher FAP-α staining percentage was observed in those patients with increased peripheral neutrophil and lymphocyte count ratio (P=0.034). FAP-α is highly expressed in cancer stroma and also a predictor of poor survival of NSCLC patients. Elevated FAP-α expression may be associated with inflammation and suppressed lymphocyte-dependent immune response, which then result in the tumor progression. Therefore, FAP-α plays an important role in the progression of NSCLC, and its high expression is a predictor of poor survival. Targeting FAP-α may be a novel strategy for NSCLC therapy.

Maternal Immunization Affects In Utero Programming of Insulin Resistance and Type 2 Diabetes

Maternal immunization with oxidized lipoproteins prior to pregnancy protects against atherogenic in utero programming by gestational hypercholesterolemia and enhances beneficial lymphocyte-dependent immune responses in offspring. To determine whether in utero programming and immunomodulation also affect insulin resistance (IR) and type 2 diabetes, we investigated the effects of immunization on glucose and insulin responses in LDL receptor-deficient mice fed regular or 60% sucrose diets, as well as in offspring fed 0.5% cholesterol or 60% sucrose diets. IR was assessed by fasting glucose and insulin levels, oral glucose tolerance tests, glucose clamps, pancreatic immunohistochemistry and plasma free fatty acid concentrations. Immunizations improved glucose responses in both genders and protected both immunized mice and their offspring against IR and type 2 diabetes. Protection occurred even under euglycemic conditions, but was greatest in obese males exposed to very obesogenic/diabetogenic conditions. Hyperinsulinemic euglycemic clamps confirmed that maternal immunization protected mainly by reducing IR, but pancreatic immunocytochemistry also indicated some protection against beta cell damage. Maternal immunization was associated with marked regulation in offspring of 4 genes relevant to diabetes and 19 genes of importance for oxidative stress, as well as increased hepatic activities of key antioxidant enzymes. These findings establish that targeted immunomodulation may be used to protect immunized subjects and their offspring against IR and type 2 diabetes, and thus to reduce cardiovascular risk. They also support the notion that in utero programming influences offspring disease not by a single mechanism, but by multiple systemic effects.

Mcl-1 Is Essential for Germinal Center Formation and B Cell Memory

Lymphocyte survival during immune responses is controlled by the relative expression of pro- and anti-apoptotic molecules, regulating the magnitude, quality, and duration of the response. We investigated the consequences of deleting genes encoding the anti-apoptotic molecules Mcl1 and Bcl2l1 (Bcl-x(L)) from B cells using an inducible system synchronized with expression of activation-induced cytidine deaminase (Aicda) after immunization. This revealed Mcl1 and not Bcl2l1 to be indispensable for the formation and persistence of germinal centers (GCs). Limiting Mcl1 expression reduced the magnitude of the GC response with an equivalent, but not greater, effect on memory B cell formation and no effect on persistence. Our results identify Mcl1 as the main anti-apoptotic regulator of activated B cell survival and suggest distinct mechanisms controlling survival of GC and memory B cells.

Role of regulator of G protein signaling 16 in inflammation-induced T lymphocyte migration and activation.

Chemokine-induced T lymphocyte recruitment to the lung is critical for allergic inflammation, but chemokine signaling pathways are incompletely understood. Regulator of G protein signaling (RGS)16, a GTPase accelerator (GTPase-activating protein) for Galpha subunits, attenuates signaling by chemokine receptors in T lymphocytes, suggesting a role in the regulation of lymphocyte trafficking. To explore the role of RGS16 in T lymphocyte-dependent immune responses in a whole-organism model, we generated transgenic (Tg) mice expressing RGS16 in CD4(+) and CD8(+) cells. rgs16 Tg T lymphocytes migrated to CC chemokine ligand 21 or CC chemokine ligand 12 injection sites in the peritoneum, but not to CXC chemokine ligand 12. In a Th2-dependent model of allergic pulmonary inflammation, CD4(+) lymphocytes bearing CCR3, CCR5, and CXCR4 trafficked in reduced numbers to the lung after acute inhalation challenge with allergen (OVA). In contrast, spleens of sensitized and challenged Tg mice contained increased numbers of CD4(+)CCR3(+) cells producing more Th2-type cytokines (IL-4, IL-5, and IL-13), which were associated with increased airway hyperreactivity. Migration of Tg lymphocytes to the lung parenchyma after adoptive transfer was significantly reduced compared with wild-type lymphocytes. Naive lymphocytes displayed normal CCR3 and CXCR4 expression and cytokine responses, and compartmentation in secondary lymphoid organs was normal without allergen challenge. These results suggest that RGS16 may regulate T lymphocyte activation in response to inflammatory stimuli and migration induced by CXCR4, CCR3, and CCR5, but not CCR2 or CCR7.

Direct and indirect pathways of immunity to pancreatic islet transplants

R esults from the Diabetes Control and Complications Trial demonstrated the importance of maintaining euglycemia for abating long-term disease complications.’ However, despite exogenous insulin therapy, complications continue to be the major source of morbidity and mortality in Type I diabetes. As such, the restoration of euglycemia through transplanting insulin-producing tissues in the form of whole organ pancreas or isolated islet tissue remains an important option for the treatment of insulin-dependent diabetes. To date, the results of pancreas transplantation has been greatly superior to islet transplantation for achieving insulin independence in Type I diabetic patients.2A However, islet transplantation continues to serve as an attractive alternative treatment due to the potential for modifling the graft (immunomodulation), the capacity for immunoisolating the grafted tissue, and for the possible use of xenogeneic donors. There are a number of obstacles that may add to the disappointing results of islet transplantation. Nonimmunologic factors may contribute to islet dysfunction, such as initial ischemia and failure of the tissue to engraft, long-term functional insufficiency in an ectopic site (eg, liver), and the potential deleterious effects of immunosuppressive agents such as cyclosporine and steroids on islet metabolism. Immunologic responses, including transplantation rejection and the recurrence of autoimmune pathogenesis associated with Type I diabetes, are also major barriers to successful islet transplantation. The focus of this discussion will be to examine the nature of T lymphocyte-dependent immune responses to pancreatic islet transplants. Emphasis will be placed on contrasting the nature of alloimmune, xenoimmune, and autoimmune responses in animal models of islet transplantation.

Neutrophils migrate to delayed-type hypersensitivity reactions in joints, but not in skin. Mechanism is leukocyte function-associated antigen-1-/Mac-1-independent.

We have previously found that polymorphonuclear leukocyte (PMNL) migration to adjuvant arthritic joints of rats was only partially inhibited by mAbs to the adhesion molecules LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18), suggesting that there is a CD11/CD18-independent mechanism for PMNL migration to inflamed joints. Adjuvant arthritis in rats is believed to be initiated by a T lymphocyte-dependent immune response and maintained by proinflammatory cytokines such as IL-1 and TNF-alpha. Here we studied two types of joint inflammation: that induced by a delayed-type hypersensitivity (DTH) reaction in the joint and that induced by intra-articular (i.a.) injection of cytokines, to explore PMNL migration to inflamed joints and examine the role of CD18. 51Cr-labeled blood PMNL were used to measure PMNL migration in rats to inflammatory reactions in joints and compared with reactions in skin. A large number of PMNL migrated to the carpal and talar joints after i.a. injection of Mycobacterium purified protein derivative in sensitized animals to induce DTH, but there was minimal PMNL migration to this DTH reaction in the skin. This migration to the joints was not inhibited by mAbs to LFA-1 alone or mAbs to LFA-1 plus Mac-1 that almost completely inhibited PMNL accumulation in dermal inflammatory reactions induced by zymosan-activated serum (C5adesArg), endotoxin, IL-1 alpha, or TNF-alpha in the same rats. Intra-articular injection of the cytokines IL-1 alpha and TNF-alpha, but not IFN-gamma, induced marked PMNL accumulation in the joints; this was strongly inhibited by the treatment of rats with anti-LFA-1 and anti-Mac-1. Thus, PMNL migrate to DTH induced in joints but not in skin, and this migration is CD18-independent, but migration to i.a. IL-1 alpha and TNF-alpha is largely CD18 dependent in both joints and skin. This suggests that both the joint microenvironment and the T cell dependence of the inflammatory reaction in the joint governs the mechanism of PMNL recruitment.

Effects of 0.60 PPM nitrogen dioxide on circulating and bronchoalveolar lavage lymphocyte phenotypes in healthy subjects

Nitrogen dioxide (NO2) is a common oxidant air pollutant. Animal studies have suggested that NO2 exposure causes a decrease in the numbers of some splenic lymphocyte subtypes and impairs lymphocyte-dependent immune responses. To investigate whether ambient levels of NO2 alter circulating and bronchoalveolar lavage fluid (BALF) human lymphocytes, we studied five healthy nonsmoking adult volunteers. In each subject, blood and bronchoalveolar lavage fluid was obtained and then, more than 2 weeks later, volunteers were exposured to 0.60 ppm NO2 for 2 hr with intermittent light to moderate exercise on 4 separate days within a 6-day period. We measured standard tests of pulmonary function (airway resistance, thoracic gas volume, maximal expiratory flow) and had the subjects rate the severity of respiratory symptoms before and after each NO2 exposure. Circulating and BALF lymphocytes were labeled with fluorochrome-conjugated monoclonal antibodies to human lymphocyte antigens and a flow cytometer was used to count lymphocyte subtypes. Neither any single day's exposure nor all four exposures caused a change in symptoms or in the results of tests of pulmonary function. The total number of circulating lymphocytes obtained after NO2 exposure was slightly greater than at baseline (1792 +/- 544 vs 1598 +/- 549 cells/mm3 at baseline; P = not significant) but the proportions of lymphocyte subtypes did not differ. In the BALF obtained after NO2 exposure and in the baseline state, the total number of lymphocytes and the percentages of T cells (CD 3), B cells (CD 20), T cytotoxic-suppressor cells (CD 8), T helper-inducer cells (CD 4), and large granular lymphocytes (CD 57) also did not differ after NO2 exposure. A slightly but significantly greater proportion of natural killer cells (CD 16) was found in the BALF obtained after NO2 exposure (7.2 +/- 3.1 vs 4.2 +/- 2.4% of total lymphocytes). We conclude that repeated exposures of healthy nonsmoking adults to 0.60 ppm NO2 are not associated with clinically significant symptoms, changes in airway caliber, or alterations in circulating and BALF lymphocyte subtypes. We suggest that brief, daily exposures to NO2 at levels higher than those achieved in urban atmosphere are unlikely to provoke acute respiratory impairment in healthy, nonsmoking adults.

Cyclosporin for a severe case of aspirin-induced asthma

Cyclosporin, an immunosupressive drug, predomi­ nantly inhibits T -lymphocyte dependent immune responses by interfering with synthesis of lymphokines. T-lymphocytes are an important source of inflammatory mediators, and some aspects of asthma may be accounted for by alterations in release of cytokines [1]. Cyclosporin was used to treat a 42 yr old woman with asthma. She has been under our treatment since 1975 when diagnosis of aspirin intolerance was estab­ lished (2, 3) by oral provocation tests. Skin tests to common airborne allergens were negative, serum immunoglobulin E (IgE) was 101 IU·m1· 1 • Her asthma was of severe type and over the years 1976-1989 she was on chronic corticotherapy at a dose of 20-30 mg·day· 1 • nature of the present report has to be stressed. We have not observed any side-effects of cyclosporin treatment, possibly because the drug was given at a low-dose. Cyclosporin side-effects are, however, of concern and should be kept in mind in patients with bronchial asthma possibly subjected to cyclosporin treatment in the future.