Antigen-induced Lymphocyte Proliferation Research Articles

APOE GENE POLYMORPHISM: THE IMPACT OF APOE4 ALLELE ON SYSTEMIC INFLAMMATION AND ITS ROLE IN THE PATHOGENESIS OF ALZHEIMER’S DISEASE

ApoE is a member of lipoprotein family. It is the most common lipoprotein in the central nervous system (CNS), secreted by astrocytes, microglia, neurons and immunocompetent cells, including lymphocytes, monocytes and macrophages. According to recent data, it has endotheliotropic and immunomodulatory functions, regulating inflammatory activation of mononuclear phagocytes and antigen-induced lymphocyte proliferation. APOE4 allele is a major genetic risk factor of Alzheimer’s disease, with prevalence 3-12 times higher in those who have this allele. Mechanisms that predispose carriers of the allele to earlier clinical presentation of neurodegeneration include changes in lipid metabolism in the CNS, in the buildup of neurotoxic amyloid-beta oligomers, in the clearance of amyloid-beta peptides from the CNS and in regulation of immune response. In this review the functions of ApoE protein in central nervous and immune system and changes in functional activity of the protein in APOE4 carriers are discussed. The impact of APOE4 allele on monocyte phenotype and inflammatory activation of monocytes, on specific cell-mediated immune response to amyloid-beta antigens and on effectiveness of immunomodulatory therapy in patients with Alzheimer’s disease summarized, as well as the possible role of changes in the immune response characteristic for APOE4 carriers in the increased risk of Alzheimer’s disease.

Combined Application of Xymedon Hydrochloride with Rabies Vaccine on the Background of Immunosupression

The effect of xymedon hydrochloride on the immune response of rabbits immunized with the rabies vaccine prepared from strain Shchelkovo-51 under the influence of immunosupression induced by cyclophosphamide has been studied. Xymedon hydrochloride was injected at a dose of 5 mg kg body weight in a volume of 1 cm3 twice a day in combination with the rabies vaccine. In addition, the immune response higher level of 1: 12800 was observed in the immunosupressed animals compared to 1: 6400 in the control animals immunized without the immunostimulant. At 6 months after vaccination, the antibody concentration of 1: 93.75 ± 44.68 remaining below the protective level was recorded, which indicated the weakness of the humoral link in the immune system. The counts of T- lymphocytes, B-lymphocytes, T-helpers, and T-suppressors in the blood of the immunesuppressed rabbits immunized with the rabies vaccine in combination with xymedon hydrochloride increased 3.2-fold, 1.9-fold, 7.7-fold, and 22.0-fold, respectively, when compared with the reference values. Therefore, the protective effect was followed by increasing the antigeninduced and spontaneuous lymphocyte proliferation, the numbers of T-helper cells and T lymphocytes exhibiting the cytotoxic and suppressive activity, and the virus-specific neutralizing antibody titers in cases wherein the Shchelkovo-51 vaccine in combination with xymedon hydrochloride was administered. It should be reasonable to apply the two-step rabies vaccination with the use of the immunostimulant, in particular, xymedon hydrochloride, to ensure the adequate immune response in immunodeficient animals.

A pilot study evaluating biomarker development for drug-induced chronic eczematous eruptions of aging individuals.

Identifying the drug(s) responsible for drug-induced chronic eczematous eruptions of aging individuals (CEEA) is a clinical challenge in patients on multiple medications. Reliable in vitro testing methods and biomarkers are needed to identify the causative agent and allow simultaneous assessment of T-cell responses to multiple drugs being taken concurrently. This study examined the feasibility of using in vitro, drug-specific T cell activation responses as a biomarker for drug-induced CEEA. This was a single center, proof-of-concept pilot study at the University of Utah Hospital, Salt Lake City, Utah. Eight aging study subjects having a history suggestive of chronic eczematous drug eruptions suspected to have resulted from calcium channel blocker (CCB) and/or hydrochlorothiazide (HCTZ) hypersensitivity plus three matched aging control subjects were identified. Drug patch testing for CCB and/or HCTZ, in vitro drug antigen-induced lymphocyte proliferation assays, and multianalyte-determined cytokine release assays were performed before and after HCTZ and/or CCB incubation. All study and control subject blood samples tested failed to demonstrate detectable enhanced lymphocyte proliferation or cytokine release to in vitro CCBs or HCTZ challenge when tested with a fairly wide range of drug concentrations. Additionally, none of the enrolled patients developed a positive patch test to CCBs and/or HCTZ. This pilot study aimed to correlate in vitro drug-induced T lymphocyte transformation and cytokine production with the presence of drug-induced CEEA. Failure to identify T cell proliferative responses to CCB drug antigens in our in vitro studies could have, in part, resulted from a pharmacologic inhibiting effect of CCB on T cell activation.

Management of hypersensivity pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to a combined type III and IV reaction with a granulomatous inflammation, caused by cytotoxic delayed hypersensitivity lymphocytes, in a Th1/Th17 milieu, chaperoned by a deficient suppressor function of T regulatory cells. Skewing toward a Th2 phenotype is reported for chronic HP. Phenotypic expression and severity depends on environmental and/or host genetic and immune co-factors. The wide spectrum of causative antigens is continuously up-dated with new sources of airborne organic particles and drug-induced HP. The diagnosis requires a detailed history, measurement of environmental exposure, pulmonary function tests, imaging, detection of serum specific antibodies, broncho-alveolar lavage, antigen-induced lymphocyte proliferation, environmental or laboratory-controlled inhalation challenge and lung biopsy. Complete antigen avoidance is the best therapeutic measure, although very difficult to achieve in some cases. Systemic steroids are of value for subacute and chronic forms of HP, but do not influence long term outcome. Manipulation of the immune response in HP holds future promise.

α-MSH-Stimulated Tolerogenic Dendritic Cells Induce Functional Regulatory T Cells and Ameliorate Ongoing Skin Inflammation

The neuropeptide α-melanocyte-stimulating hormone (α-MSH) is a well-known mediator of skin pigmentation. More recently, it has been shown that α-MSH also exerts a strong anti-inflammatory and immunosuppressive activity. To elucidate the mechanisms underlying α-MSH-induced immunosuppression, we investigated whether α-MSH affects dendritic cell/T cell communication, as especially this interaction has an important role in the regulation of immune responses. Here, we show that α-MSH, by binding to MC-1R, induced tolerogenic dendritic cells, which were capable of expanding CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) in vitro, as well as in vivo. Notably, those α-MSH-induced Tregs were functional as they efficiently inhibited cutaneous contact allergy and ongoing psoriasis-like skin inflammation in mice. Furthermore, α-MSH induced tolerogenic dendritic cells capable of generating functional Tregs in human blood. Interestingly, human Tregs expanded via α-MSH-stimulated dendritic cells suppressed the proliferation and cytokine secretion of pathogenic T-helper-17 (Th17) cells from individuals with psoriasis. Taken together, these data indicate that α-MSH induced immunosuppressive Tregs in vitro and in vivo, which inhibited disease progression in a mouse model of psoriasis-like skin inflammation and suppressed the activation and proliferation of effector T cells from subjects with psoriasis.

The effects of a novel adjuvant complex/ Eimeria profilin vaccine on the intestinal host immune response against live E. acervulina challenge infection

The effects of a novel adjuvant composed of Quil A, cholesterol, dimethyl dioctadecyl ammonium bromide, and Carbopol (QCDC) on protective immunity against avian coccidiosis following immunization with an Eimeria recombinant protein were determined. Broiler chickens were subcutaneously immunized with isotonic saline (control), Eimeria recombinant profilin alone, or profilin emulsified with QCDC at 1 and 7 days post-hatch, and orally challenged with live Eimeria acervulina at 7 days following the last immunization. Body weight gains, gut lesion scores, fecal oocyst outputs, profilin serum antibody titers, lymphocyte proliferation, and intestinal cytokine transcript levels were assessed as measures of protective immunity. Chickens immunized with profilin plus QCDC showed increased body weight gains and decreased intestinal lesion scores compared with the profilin only or control groups. However, no differences were found in fecal oocyst shedding among the three groups. Profilin serum antibody titers and antigen-induced peripheral blood lymphocyte proliferation in the profilin/QCDC group were higher compared with the profilin only and control groups. Finally, while immunization with profilin alone or profilin plus QCDC uniformly increased the levels of intestinal transcripts encoding all cytokines examined (IL-1β, IL-10, IL-12, IL-15, IL-17F, and IFN-γ) compared with the control group, transcripts for IL-10 and IL-17F were further increased in the profilin/QCDC group compared with the profilin only group. In summary, this study provides the first evidence of the immunoenhancing activities of QCDC adjuvant in poultry.

A Comparison Between (3H)-thymidine Incorporation and Isothermal Microcalorimetry for the Assessment of Antigen-induced Lymphocyte Proliferation

Lymphocyte transformation tests (LTT) are time-consuming radioactive assays used in the clinic for the determination of allergic drug reactions and extensively in basic immunological research. In the present study we propose an alternative method in the monitoring of T-cell responses by isothermal microcalorimetric (IMC) measurements of overall cellular heat production as a function of time. For mitogen-induced lymphocyte proliferation, we analyzed a concentration dependent effect of phytohemaglutinin (PHA) and both tests showed a good correlation. This was also the case for specific antigenic stimulation with Varidase® or tetanus toxoid. On the other hand, antigen-induced lymphocyte proliferation analyzed by pre and post influenza vaccine (Inflexal® V) samples, showed no such correlation. Our study suggests that IMC measurements, despite the advantages of simplicity, on-line recording of metabolic activity and no use of radioactivity, may be limited to monitoring mitogen-induced lymphocyte proliferation.

Congenic strains displaying similar clinical phenotype of arthritis represent different immunologic models of inflammation

Proteoglycan (PG)-induced arthritis (PGIA) is an autoimmune inflammatory disease controlled by multiple genes in the murine genome. BALB/c x DBA/2 congenic strains carrying four major PGIA chromosome loci were immunized, and positions of loci on chromosomes 3, 7, 8 and 19 (loci Pgia26, Pgia21, Pgia4 and Pgia12, respectively) were confirmed. Each congenic strain exhibited a different pattern of regulation of clinical and immunologic features of PGIA, and these features were significantly influenced by gender. Locus Pgia26 delayed PGIA onset in males and females, and the effect was associated with a lower rate of antigen-induced lymphocyte proliferation and lower production of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4). Pgia12 similarly delayed onset in males, but the effect was achieved by elevated proliferation of PG-specific lymphocytes and enhanced production of IFN-gamma and IL-4. The effect of the Pgia21 locus was arthritis-suppressive in females but PGIA-permissive in congenic males. These opposite effects are attributed to two-fold higher serum autoantibody and IL-6 levels in males than in females. Our study supports the idea that each congenic strain represents a different immunologic subtype of PGIA, providing an explanation for the complex etiology and various clinical phenotypes of rheumatoid arthritis.

A clinical study of hypersensitivity pneumonitis presumably caused by feather duvets

Bird fancier's lung (BFL) is a type of hypersensitivity pneumonitis induced by the inhalation of bird-related antigens. The BFL induced by feathers is difficult to diagnose because feathers are generally unrecognized as a causative antigen. To determine the clinical features of BFL presumably induced by feather duvets (feather duvet lung) to provide clues for diagnosis. We performed a retrospective review of the medical records of patients with feather duvet lung evaluated between April 1, 2000, and June 30, 2003, at the Tokyo Medical and Dental University Hospital in Japan. Seven patients with feather duvet lung were included in this study; 4 patients had acute disease and 3 had chronic BFL. Duration of contact with feather duvets was 1 month to 10 years. Serum KL-6 and surfactant protein D levels were elevated in all the patients. Specific antibodies against avian antigens were positive in acute BFL but negative in chronic BFL. Antigen-induced lymphocyte proliferation in peripheral blood or bronchoalveolar lavage cells was positive in all the patients. The diagnosis was confirmed by an environmental or inhalation provocation test. Feather duvets can induce acute and chronic BFL. Physicians should be aware of feather duvets as a cause of BFL because feather duvets are becoming more prevalent.

Hypersensitivity Pneumonitis

Hypersensitivity pneumonitis (HP) represents a group of lung disorders caused by the inhalation of a wide variety of organic particles by susceptible individuals. HP occurs mainly in nonsmokers, but smoking may promote an insidious and chronic disease. The prevalence of HP is difficult to estimate accurately since several antigens can produce the disease, but the range spans infancy to old age. Regardless of the causative antigen or its environmental setting, the clinical manifestations are essentially the same. Three different clinical presentations have been recognized: acute, subacute, and chronic. In the acute form, patients show flu-like symptomatology, followed by dyspnea and dry cough. Symptoms subside a few hours or days later. The subacute and chronic forms result from recurrent low-level antigen exposure and are characterized by progressive dyspnea and dry cough. Other constitutional symptoms such as fatigue, anorexia, and weight loss can be apparent. Fever may occur in the subacute form. Importantly, chronic HP may evolve insidiously or may result from repeated acute/subacute episodes. Recurrent acute, subacute, and chronic HP may progress to irreversible lung fibrosis or provoke emphysematous changes.HP can be difficult to identify, and precise diagnosis requires a history of exposure and a constellation of clinical, imaging, laboratory, bronchoalveolar lavage and pathologic findings. General laboratory tests show an increase of acute phase reactants. Specific precipitating antibodies, when present, are evidence of antigen exposure, and are a hallmark for diagnosis. Chest radiograph usually reveals widespread ground-glass attenuation, and nodular or reticulonodular shadowing. High-resolution CT features include diffuse or patchy ground-glass opacities with small poorly defined nodules and air trapping. Pulmonary function tests are characterized by a predominantly restrictive ventilatory defect with loss of lung volume and hypoxemia at rest that worsens with exercise. Bronchoalveolar lavage reveals a significant increase in lymphocytes, mostly over 40%. In the acute form there is also an increase in neutrophils. Antigen-induced lymphocyte proliferation, and environmental or laboratory-controlled inhalation challenge, may be used for diagnostic purposes and can help to establish a diagnosis of insidious forms of HP. In subacute or chronic cases, lung biopsy may be necessary. Typical findings include bronchiolitis, lymphocytic alveolitis, and loosely formed granulomas, although occasionally other morphologic patterns such as nonspecific interstitial pneumonia may exist. Treatment focuses on avoiding further exposure to the offending antigen(s). Corticosteroids are recommended in subacute and chronic forms. The usual regimen consists of initial high doses of systemic corticosteroid (e.g. prednisone 0.5-1.0 mg/kg/day), followed by gradual tapering.

α-Melanocyte-Stimulating Hormone Suppresses Antigen-Induced Lymphocyte Proliferation in Humans Independently of Melanocortin 1 Receptor Gene Status

Studies in mice indicate that alpha-melanocyte-stimulating hormone (alphaMSH) is immunosuppressive, but it is not known whether alphaMSH suppresses human immune responses to exogenous Ags. Human PBMCs, including monocytes, express the melanocortin 1 receptor (MC1R), and it is thought that the ability of alphaMSH to alter monocyte-costimulatory molecule expression and IL-10 release is mediated by this receptor. However, the MC1R gene is polymorphic, and certain MC1R variants compromise receptor signaling via cAMP, resulting in red hair and fair skin. Here, we have investigated whether alphaMSH can suppress Ag-induced lymphocyte proliferation in humans and whether these effects are dependent on MC1R genotype. alphaMSH suppressed streptokinase-streptodornase-induced lymphocyte proliferation, with maximal inhibition at 10(-13)-10(-11) M alphaMSH. Anti-IL-10 Abs failed to prevent suppression by alphaMSH, indicating that it was not due to MC1R-mediated IL-10 release by monocytes. Despite variability in the degree of suppression between subjects, similar degrees of alphaMSH-induced immunosuppression were seen in individuals with wild-type, heterozygous variant, and homozygous/compound heterozygous variant MC1R alleles. RT-PCR of streptokinase-streptodornase-stimulated PBMCs for all five melanocortin receptors demonstrated MC1R expression by monocytes/macrophages, MC1R and MC3R expression by B lymphocytes, but no melanocortin receptor expression by T lymphocytes. In addition, alphaMSH did not significantly inhibit anti-CD3 Ab-induced lymphocyte proliferation, whereas alphaMSH and related analogs (SHU9119 and MTII) inhibited Ag-induced lymphocyte proliferation in monocyte-depleted and B lymphocyte-depleted assays. These findings demonstrate that alphaMSH, acting probably via MC1R on monocytes and B lymphocytes, and possibly also via MC3R on B lymphocytes, has immunosuppressive effects in humans but that suppression of Ag-induced lymphocyte proliferation by alphaMSH is independent of MC1R gene status.

Does High Organochlorine (OC) Exposure Impair the Resistance to Infection in Polar Bears (Ursus maritimus)? Part II: Possible Effect of OCs on Mitogen- and Antigen-Induced Lymphocyte Proliferation

Previous studies have reported alarmingly high levels of organochlorines (OCs), particularly polychlorinated biphenyls (PCBs), in free-ranging polar bears (Ursus maritimus). In this study plasma concentration of PCBs ranged from 14.8 to 200 ng/g wet weight. The aim of the study was to investigate associations between OCs and lymphocyte proliferation after in vitro stimulation with different mitogens and antigens. In 1998 and 1999, 26 and 30 free-ranging polar bears from Svalbard and Churchill, Canada, respectively, were recaptured 32–40 d following immunization with inactivated tetanus toxoid and hemocyanin from keyhole limpets (KLH) to sensitize lymphocytes. At recapture, blood was sampled for determination of plasma levels of PCBs and organochlorine pesticides (OCPs) and lymphocyte proliferation after in vitro stimulation with specific mitogens—phytohemagglutinin (PHA), pokeweed mitogen (PWM), concanavalin A (Con A), lipopolysaccharide (LPS), and purified protein derivative of Mycobacterium aviumsubsp. paratuberculosis (PPD)—and antigens: tetanus toxoid and KLH. The combinations of ΣPCBs (sum of 12 individual PCB congeners), ΣOCPs (sum of 6 OCPs), and their interactions contributed up to 15% of the variations in the lymphocyte responses. By using multiple regression analyses, followed by classical mathematic function analyses, thresholds for immunomodulation were estimated. Depending on the lymphocyte proliferation response studied, the estimated thresholds for significant immunomodulation were within the concentration ranges 32–89 ng/g wet weight (ww) and 7.8–14 ng/g ww for ΣPCBs and ΣOCPs, respectively. Thus, this study demonstrated that OC exposure significantly influences specific lymphocyte proliferation responses and part of the cell-mediated immunity, which also is associated with impaired ability to produce antibodies (Lie et al., 2004).The authors thank the Norwegian Research Council (NFR, numbers 125693/720 and 140730/720), the Norwegian Ministry of Environment Transport and Effect Program, and the Toxic Substances Research Initiative in Canada for funding this study. The authors thank Tine Borgen for technical assistance in the lymphocyte proliferation test.

Clinical features of recurrent and insidious chronic bird fancier's lung

Chronic bird fancier's lung (BFL) can be subgrouped into two types. One subgroup of patients develops interstitial pulmonary fibrosis after recurrent acute episodes (recurrent BFL), and the other subgroup of patients has no history of acute episodes but has slowly progressive chronic respiratory disease (insidious BFL). To define the clinical characteristics of both types of BFL and to provide clues for diagnosis. We performed a retrospective review of the medical records of patients with chronic BFL who were evaluated between October 1992 and March 2001 at the Tokyo Medical and Dental University Hospital in Japan. Patients were evaluated for their clinical characteristics, including history, laboratory, and immunologic findings; imaging; bronchoalveolar lavage; and histologic findings. Thirty-two patients with chronic BFL were included in this study; 15 patients had recurrent BFL and 17 had insidious BFL. The patients with recurrent BFL tended to breed dozens of pigeons in a loft, whereas the patients with insidious BFL were likely to be exposed to smaller birds kept indoors. Specific antibodies against pigeon dropping extracts or budgerigar dropping extracts were positive in 87% of the recurrent BFL cases and 35% of the insidious BFL cases. Antigen-induced lymphocyte proliferation was positive in more than 90% of both groups. The upper lung field was frequently involved in both groups as demonstrated by chest radiographic findings. In all of the patients with insidious BFL, the diagnosis was confirmed by positive laboratory-controlled inhalation test results. Insidious BFL may be misdiagnosed as idiopathic pulmonary fibrosis if a careful history is not taken and antigen-induced lymphocyte proliferation, careful imaging evaluation, and laboratory-controlled inhalation challenge testing are not conducted. In contrast, the clinical findings of recurrent BFL are consistent with hypersensitivity pneumonitis induced by other antigens.

Selective elimination of synovial inflammatory macrophages in rheumatoid arthritis by an Fcgamma receptor I-directed immunotoxin.

To determine whether monocyte/macrophages from rheumatoid arthritis (RA) patients can be selectively eliminated by a toxin-conjugated antibody CD64-ricin A (CD64-RiA) directed toward the high-affinity receptor for IgG (FcgammaRI), exploiting the capacity of FcgammaRI to efficiently endocytose antibody which it has bound. Mononuclear cells from peripheral blood (PB) and synovial fluid (SF) obtained from RA patients were cultured in the presence of CD64-RiA. Cell death of monocyte/macrophages was measured by phenotypic changes (light-scatter patterns and CD14 and FcgammaRI expression) and apoptosis (nuclear DNA fragmentation). We then tested whether CD64-RiA-induced cell death of macrophages affected their capacity to stimulate antigen-induced lymphocyte proliferation and to secrete cytokines. Additionally, the capacity of CD64-RiA to inhibit proinflammatory activity and cartilage degradation by RA synovial tissue explants was evaluated. Inflammatory macrophages from RA SF expressed elevated levels of FcgammaRI and were selectively eliminated by CD64-RiA via apoptotic cell death. Monocyte/macrophages from RA PB, which had lower levels of FcgammaRI expression, were much less affected. Induction of SF macrophage apoptosis was associated with efficient inhibition of antigen-induced lymphocyte proliferation and a reduction in tumor necrosis factor alpha (TNFalpha) release. Consistent with these effects on SF macrophages, CD64-RiA also inhibited TNFalpha production, interleukin-1beta production, and cartilage-degrading activity of RA synovial tissue explants. Together, these data underscore the crucial role of synovial macrophages in RA joint inflammation and indicate that selective elimination of these cells through FcgammaRI-directed immunotoxins could be a novel approach to the treatment of RA.

Splenic T cells from mice receiving intracameral antigen suppress in-vitro antigen-induced proliferation and interferon-? production by sensitized lymph node cells

Purpose: To characterize the immunoregulatory mechanisms in vitro of spleen cells that are activated by intracameral injection of antigen (AC-spleen cells). Methods: AC-spleen cell regulation of in-vitro antigen-induced proliferation and interferon-? production by lymph node cells from TNP-BSA-immunized mice was quantified by co-culture of the lymph node cells with TNP-BSA and AC-spleen cells induced by intracameral TNP-BSA. Cytokine production was quantified by ELISA. Results: AC-spleen cells produced significantly more IL-4 and IL-10 than spleen cells from TNP-BSA-immunized mice or naive spleen cells; unlike spleen cells from immunized mice, AC-spleen cells did not produce IFN-?. AC-splenic CD4 + , CD8 + , CD4 - /CD8 - (DN) T cells differentially suppressed antigen-induced proliferation and IFN-? production by immunized lymph node cells by a mechanism dependent on IL-10 and antigen. Cultures of lymph node cells, antigen, and AC-splenic T cells contained increased amounts of IL-10 and/or TGFß2. Conclusions: The differential, cytokinedependent immunoregulatory effects of CD4 + and CD8 + AC-spleen cells observed in vitro parallel their effects in vivo. We suggest that the suppression of antigen-induced lymphocyte proliferation and IFN-? production by AC-spleen cells provides a useful in-vitro assay of the immunoregulatory activity of cell populations that are induced by the injection of antigen into the anterior chamber.

Stress, immune regulation, and immunity: applications for asthma.

The neuroendocrine mediators reach the cells of the immune system either through the peripheral circulation or through direct innervation of lymphoid organs. Primary and secondary lymphoid organs are innervated by sympathetic nerve fibers. Lymphocytes and monocytes express receptors for several stress hormones, including CRH, ACTH, cortisol, norepinephrine, and epinephrine. Therefore, it is reasonable to conclude that the neuroendocrine hormones released during a stressful event could alter immune function and subsequently alter the course of immune-based diseases. The impact of psychological stress on immune function has been the subject of extensive research efforts. Using a variety of models from largely healthy humans undergoing various forms of natural and experimental stress models, stress has been associated with suppression of NK activity, mitogen- and antigen-induced lymphocyte proliferation and in vitro production of IL-2 and IFN-gamma. Psychological stress is also associated with a higher rate of in vivo hypoergy to common recall-delayed type hypersensitivity antigens. These studies have suggested that psychological stress suppresses various components of CMI responses. Also, data suggest that chronic stress does not simply suppress the immune system, but induces a shift in the type-1/type-2 cytokine balance toward a predominant type-2 cytokine response. Such a change would favor the inflammatory milieu characteristic of asthma and allergic diseases. Recent studies using well-controlled teenage asthmatic subjects demonstrated immunological changes (decreased NK cell cytotoxicity and cytokine alterations) in response to exam stress. These immune alterations are consistent with a cytokine milieu that could potentially worsen asthma. However, there were no changes in peak flow rates, self-report asthma symptoms, or medication use. The lack of correlation between stress and asthma symptoms may have been related to the timing of the visits in relation to the stressor, the duration of the stressor, disease severity, or a lack of accurate self-report data. Alternatively, stress-mediated exacerbations of asthma may require multiple alterations by stress, including cytokine dysregulation or vagal-mediated airway hyperresponsiveness. The rationale for stress management in asthma is based upon the notion that stress causes a change in immune balance that would favor asthma activity in susceptible individuals. This immune imbalance can be found in TH1/TH2 cytokine changes that occur with stress. Although it has not yet been demonstrated that stress can cause or directly influence the development of asthma, it is interesting to note that both the incidence and prevalence of asthma continue to increase and are higher in urban than in rural areas. Among other differences is the well-appreciated higher chronic stress levels associated with urban living.

Chronic hypersensitivity pneumonitis in Japan: A nationwide epidemiologic survey

Background: Pulmonary fibrosis inevitably develops in patients with chronic hypersensitivity pneumonitis (HP). Objective: We conducted a nationwide epidemiologic study in Japan to evaluate the frequency and clinical characteristics of chronic HP. Methods: This report is on 36 cases of chronic HP, including 10 patients with summer-type HP, 5 patients with home-related HP, 7 patients with bird fancier’s lung, 5 patients with isocyanate-induced HP, 4 patients with farmer’s lung, and 5 patients with other types of chronic HP. Chronic HP was further subgrouped into 2 types: one type of patients were first seen with chronic disease (9 patients), and the other type became chronic with fibrosis after repeated acute episodes (27 patients). Results: The upper lung field was frequently involved in chronic HP (17%). Ground-glass opacities were observed in 57% and air space consolidation in 30% of the patients. Honeycombing was apparent in 37%. Twenty-six of 28 patients had antibodies to the presumptive antigens. Five of 8 patients with chronic HP were positive for antigen-induced lymphocyte proliferation. In 2 cases patients did not have detectable antibodies to causative antigens, although antigen-induced lymphocyte proliferation was detectable. The ratio of CD4 to CD8 in BAL lymphocytes was lowest in isocyanate-induced HP (mean 0.22) and tended to be high in farmer’s lung and bird fancier’s lung. Granulomas were observed in 39% and Masson bodies in 42% of specimens on histologic examination. Administration of prednisolone was effective in 58% of patients. Conclusions: The insidious form of chronic HP has probably been misdiagnosed as idiopathic pulmonary fibrosis when a good history was not taken and immunologic (especially antigen-induced lymphocyte proliferation) and BAL testing were not counted. (J Allergy Clin Immunol 1999;103:315-20.)

The effects of TYB-2285 and its metabolites on lymphocyte responses In vitro

1. 1. We examined the effects of TYB-2285 and its metabolites (TC-286 and TC-326) on antigen-induced lymphocyte proliferation, allogeneic mixed lymphocyte reaction (MLR) and mitogen-induced lymphocyte proliferation. 2. 2. Splenic lymphocytes from C57BL/6 strain mice sensitized with human serum albumin were cultured with the antigen in the presence of TYB-2285 or its metabolites (10 −7-10 −4M). The lymphocyte proliferation enhanced by antigen was inhibited by TYB-2285 and its metabolites in a dose-dependent manner. 3. 3. Splenic lymphocytes collected from C57BL/6 and Balb/C strain mice were cocultured in the presence of TYB-2285 and its metabolites (10 −7-10 −4M). Allogeneic MLR was inhibited by TYB-2285 and its metabolites in a dose-dependent manner. 4. 4. Splenic lymphocytes from C47BL/6 strain mice were cultured with concanavalin A (Con A) in the presence of TYB-2285 and its metabolites (10 −7-10 −4M).TYB-2285 and its metabolites did not affect Con A-induced lymphocyte proliferation. Cyclosporin A showed an inhibitory effect on Con A-induced lymphocyte proliferation that was as strong as the inhibitory effect on antigen-induced lymphocyte proliferation and allogeneic MLR at a lower concentration.

Identification of T-cell epitope sequences on an important mite antigen.

T-cell epitopes on Der 1 and Der 2 groups, the major mite allergens, have been intensively analysed, while those on the other important allergens remain to be elucidated. We have cloned four cDNAs coding for important mite allergens on the basis of frequency and capacity of IgE binding. Stimulatory action of glutathione S-transferase-fused Mag1 on lymphocytes from mite-allergic patients was relatively high among them. To identify T-cell epitopes on Mag1, we studied the stimulating activity of truncated Mag1 proteins and synthetic peptides on proliferative response of lymphocytes from mite antigen-immunized mice and mite-sensitive patients. Truncated Mag1 proteins were expressed as a fusion protein with beta-galactosidase in Escherichia coli pop2136 carrying a variety of deleted Mag1 inserts. Murine T-cell epitope regions were estimated by the truncated antigen-induced lymphocyte proliferation assay. Overlapping peptides covering the whole sequence of the presumed T-cell epitope regions were synthesized to identify the epitope core sequences using murine and human Mag1-specific T-cell lines. Amino acid range 56-70 on Mag1 molecule showed remarkable stimulatory action on murine T cells, while amino acid ranges 51-65 and 86-100 had potent stimulatory activity on human T cells. These results suggest that Mag1 is a valuable antigen suitable for studies on T-cell responses and T-cell epitopes in mice and humans.

Defective antigen-induced lymphocyte proliferation in the X-linked hyper-IgM syndrome

We examined T-cell proliferation in five patients with X-linked hyper-IgM syndrome (XHIM), using a panel of antigens and lectins. All patients had impaired antigen-induced proliferation, whereas their lectin responses were normal. Thus, in addition to severely depressed antibody responses, patients with XHIM have a defect in antigen-specific T-cell proliferation, which may explain their susceptibility to pathogens such as Pneumocystis carinii. (J Pediatr 1997;131:147-50)