Immunotoxicity assessment of sub-chronic oral administration of acetamiprid in Wistar rats.

CONTEXT: Neonicotinoid insecticides are synthetic analogues of nicotine that acts on the central nervous system of insects by blocking post synaptic acetylcholine receptor. Acetamiprid is one of the widely used neonicotinoid class of insecticide used to control sucking insects like aphids, bees, mosquitoes, on crops. Data on the possible immunotoxic nature of acetamiprid are lacking. OBJECTIVE: The present study was conducted in Wistar rats with the objective of evaluating the immunotoxic potential of acetamiprid administered orally at the dose levels of 27.5, 55 and 110 mg/kg b.w. (equivalent to 5.5, 11 and 22 mg/kg b.w.) for a period of 90 days. MATERIALS AND METHODS: In experiment 1, general toxicity testing including the evaluation of clinical signs, hemato-biochemical changes, response of the lymphocytes towards T and B cell mitogens, macrophage function, gross and histopathology of the lymphoid organs (spleen, thymus, lymph nodes, etc.) were performed. In the second experiment, humoral and cell-mediated responses during immunological challenges were evaluated. RESULTS: Significant decreases were observed in the stimulation index of lymphocyte proliferation to B cell mitogen and in the nitrite production of macrophages of rats treated with 110 mg/kg of acetamiprid. Significant decrease in the lymphoproliferative response towards the B cell mitogen indicated the inability of the B lymphocytes to respond on stimulation that might increase the chances of susceptibility to infections. Acetamiprid also caused 15-28% reduction in nitrite production, an important signal for efficient inflammatory response of macrophages. The functional impairment of macrophages may involve aberrations in the enzymatic degradation of microbes, oxidative burst, generation of free radicals, phagocytosis, release of proinflammatory cytokines and thereby, may hamper host defence causing susceptibility to diseases. No significant changes over hematology, biochemistry, organ weights, histopathology of major immune organs, delayed type hypersensitivity test, response to sRBCs and lymphoproliferation assay for T cell mitogen were observed. CONCLUSION: In conclusion, the results demonstrate for the first time that the subchronic administration of acetamiprid (20% SP-soluble powder) cause significant decreases in the lymphocyte proliferation as well as the macrophage function at the dose level of 110 mg/kg. Considering the chronic population adjusted dose (0.023 mg/kg/day) through dietary exposure for acetamiprid, judicious use of acetamiprid is highly essential. Indiscriminate use of acetamiprid exceeding the doses advised might pose a hazard.

AE37 peptide vaccination in prostate cancer: a 4-year immunological assessment updates on a phase I trial.

In our recent phase I trial, we demonstrated that the AE37 vaccine is safe and induces HER-2/neu-specific immunity in a heterogeneous population of HER-2/neu (+) prostate cancer patients. Herein, we tested whether one AE37 boost can induce long-lasting immunological memory in these patients. Twenty-three patients from the phase I study received one AE37 boost 6-month post-primary vaccinations. Local/systemic toxicities were evaluated following the booster injection. Immunological responses were monitored 1-month (long-term booster; LTB) and 3-year (long-term immunity; LTI) post-booster by delayed-type hypersensitivity, IFN-γ ELISPOT and proliferation assays. Regulatory T cell (Treg) frequencies, plasma transforming growth factor-ß (TGF-ß) and indoleamine 2,3-deoxygenase (IDO) activity levels were also determined at the same time points. The AE37 booster was safe and well tolerated. Immunological monitoring revealed vaccine-specific long-term immunity in most of the evaluated patients during both LTB and LTI, although individual levels of immunity during LTI were decreased compared with those measured 3 years earlier during LTB. This was paralleled with increased Tregs, TGF-ß levels and IDO activity. One AE37 booster generated long-term immunological memory in HER-2/neu (+) prostate cancer patients, which was detectable 3 years later, albeit with a tendency to decline. Boosted patients had favorable clinical outcome in terms of overall and/or metastasis-free survival compared with historical groups with similar clinical characteristics at diagnosis. We suggest that more boosters and/or concomitant disarming of suppressor circuits may be necessary to sustain immunological memory, and therefore, further studies to optimize the AE37 booster schedule are warranted.

[Medical and biological safety assessment of genetically modified maize event MIR604].

There are presented the results of genotoxicologic, immunologic and allergologic examinations which were conducted within the framework of integrated medical and biological assessment of genetically modified rootworm Diabrotica spp.-protected maize event MIR604. Analysis of damages of DNA and structural chromosome aberrations, assessment of the allergenic potential and immunoreactive properties has not confirmed any genotoxic, allergenic and immunotoxic effect of maize event MIR604.

T cell assessment in allergic drug reactions during the acute phase according to the time of occurrence.

Allergic drug reactions can be classified as immediate, accelerated or delayed. This classification usually correlates with the mechanism involved: immediate reactions are IgE mediated and delayed reactions are T cell dependent. We analyzed lymphocyte involvement in patients with these reactions by determining cell subpopulations, activation state and skin homing receptor expression (CLA) in blood and skin. Patients with immediate, accelerated and delayed reactions were evaluated during the acute phase and after resolution. Controls taking drugs were included. Phenotypic immunofluorescence analysis was done by flow cytometry in peripheral blood, and by immunohistochemistry in skin for delayed reactions. Forty-six patients were included, 17 with immediate reactions, 10 accelerated and 19 delayed. At the acute phase CLA was significantly increased in delayed reactions and HLA-DR in all three types of reaction. In the severest delayed reactions, Steven-Johnson/Lyell syndromes, the CD4 subsets were increased in peripheral blood and skin compared to maculopapular exanthemas and urticaria and HLA-DR when compared with urticaria. In maculopapular exanthemas CLA was significantly increased in peripheral blood and skin compared to urticaria and the severe reactions. We found that T-cells are implicated, besides delayed reactions, in immediate and accelerated reactions. In delayed reactions there is a parallelism between results found in skin and peripheral blood with a higher participation of CD4+ cells the more severe the reaction.

Delayed-type hypersensitivity skin test reactivity and survival in HIV-infected patients in Uganda: should anergy be a criterion to start antiretroviral therapy in low-income countries?

Access to antiretroviral (ARV) drugs is improving in sub-Saharan Africa but still constrained by several clinical and logistical obstacles. There is a need to develop affordable markers to guide initiation of treatment. We present a prospective cohort study of 779 patients participating in a TB prophylaxis trial. We performed separate analyses for anergic and nonanergic subjects. Prognostic factors for anergic and nonanergic subjects differed between groups. Individuals with anergy and constitutional symptoms were at the highest risk of death. Incident tuberculosis and CD4 < 200 cells/muL at enrollment were the strongest risk factors for death. HIV disease is associated with substantial morbidity and mortality in this population. The burden caused by tuberculosis is particularly high. Anergy is a strong and independent predictor of death. World Health Organization criteria to start ARV may be strengthened with the addition of DTH testing, an inexpensive and readily available tool in sub-Saharan Africa.

Development of an anti-IL-12 p40 auto-vaccine: protection in experimental autoimmune encephalomyelitis at the expense of increased sensitivity to infection.

IL-12 and IL-23, which share the IL-12 p40 subunit, have been ascribed central roles in many autoimmune disorders. We describe here an anti-IL-12 (alphaIL-12) auto-vaccine that potentially blocks both factors in vivo. Immunization of mice with mouse IL-12 coupled to OVA or Pan DR epitope (PADRE) peptide induced Ab directed against the IL-12 p40 subunit, which prevented IFN-gamma production in response to IL-12 administration in vivo. Experimental autoimmune encephalomyelitis, an IL-23-dependent disease model, induced in SJL mice with a proteolipid protein (PLP) peptide was almost undetectable after alphaIL-12 vaccination. Myelin oligodendrocyte glycoprotein (MOG)-induced disease in C57BL/6 mice was also significantly inhibited. This protection correlated with inhibited Th1 cytokine responses in vitro and with an increase in the IgG1/IgG2a anti-PLP Ab balance. Detrimental consequences of alphaIL-12 vaccination were evaluated in C57BL/6 mice infected with Leishmania major (L.m.). While delayed-type hypersensitivity (DTH) suppression and immunoglobulin as well as interleukin production patterns reflected a major shift toward a Th2-type response, L.m. growth was still significantly retarded as compared to that seen in susceptible BALB/c mice. However, vaccinated animals ultimately failed to control parasite expansion. These results suggest that some chronic autoimmune diseases may benefit from alphaIL-12 vaccination at the expense of reduced, but not completely abrogated, cell-mediated immunity.

[Immunotoxicologic assessment of transgenetic rice].

OBJECTIVE: To assess the immunotoxicologic aspect of transgenetic plant. METHODS: BALB/C mice were fed with food composed by transgenic rice (into which cowpea trypsin inhibitor gene was introduced) or nontransgenetic rice (which has the same gene composition as the transgenic rice except for the cowpea trypsin inhibitor gene) for 30 days. All food is made according to the composition of AIN-93G. In the end, all kinds of immunotoxicologic indexes of mice of every group were compared such as body weight, guts index, blood routine test, lymphocyte sort, serum antibody titter, plaque forming cell, delayed hypersensitivity response, macrophage function test. RESULTS: All immunotoxicologic indexes of mice fed either by transgenic rice or nontransgenetic rice have no differences to those of mice fed by normal food. CONCLUSION: Transgenic rice is substantially equivilent to nontransgenetic rice in immunotoxicologic aspect.

Detailed criteria for the assessment of clinical symptoms in a new murine model of severe allergic conjunctivitis.

PURPOSE: The aims of this research were to: (1) generate a rapid protocol for the sensitization of rodents to a defined allergen without footpad injections yet leading to both acute- and late-phase hypersensitivity reactions in the ocular surface; and (2) define detailed criteria for the assessment of clinical symptoms in the acute-phase response. METHODS: With the approved methods for the use of experimental animals in research and existing sensitization protocols as a starting point, we developed and tested a new protocol with respect to its ability to generate an acute- and late-phase response on ocular challenge. Clinical symptoms were assessed by a trained ophthalmologist under masked conditions, and late-phase responses determined by histologic analysis of conjunctival tissue sections. RESULTS: A new protocol for the rapid sensitization of mice, avoiding footpad injections, yet yielding both acute- and late-phase allergic responses, was developed. Detailed criteria for the assessment of disease severity were established and tested. CONCLUSION: This protocol establishes a murine model of allergic conjunctivitis that will be useful for both the study of the molecular and cellular basis of allergic reactions in the ocular surface and the testing of new therapies for this disease.

Comparative assessment of TCRBV diversity in T lymphocytes present in blood, metastatic lesions, and DTH sites of two melanoma patients vaccinated with an IL-7 gene-modified autologous tumor cell vaccine.

A phase I clinical trial using autologous, IL-7 gene-modified tumor cells in patients with disseminated melanoma has been recently completed. Although no major clinical responses were observed, increased antitumor cytotoxicity was measured in postvaccine peripheral blood lymphocytes in a subset of treated patients. To analyze the in situ immune response, the T cell receptor beta-chain variable region (BV) repertoire of T cells infiltrating postvaccine lesions was studied in two patients, and compared with that of T cells present in prevaccine ones, in peripheral blood lymphocytes, and, in one patient, in delayed type hypersensitivity (DTH) sites of autologous melanoma inoculum. A relative expansion of T cells expressing few BVs was observed in all postvaccine metastases, and their intratumoral presence was confirmed by immunohistochemistry. Length pattern analysis of the complementarity determining region 3 (CDR3) indicated that the repertoire of T cells expressing some of these BVs was heterogeneous. At difference, CDR3, beta-chain joining region usage, and sequence analysis enabled us to demonstrate, within a T-cell subpopulation commonly expanded at DTH sites and at the postvaccine lesion of patient 1, that both DTH sites contained identical dominant T-cell clonotypes. One of them was also expressed at increased relative frequency in the postvaccine lesion compared to prevaccine specimens. These results provide evidence for immunological changes, including in situ clonally expanded T cells, in metastases of patients vaccinated with IL-7 gene-transduced cells.

[Infants 12 month-old or less as a high risk group in tuberculosis--comparison of clinical data with those in children aged one to two years].

A number of tuberculosis (TB) infants 12 month-old or less is larger than the ones of any other age groups with childhood TB in our hospital. This study was undertaken to elucidate clinically why infants 12 month-old or less suffered from TB most among infants and early children. We studied tuberculin skin reaction, isolation frequency of Mycobacterium tuberculosis (MTB) in gastric aspirates, and frequency of systemic dissemination of TB among 45 TB infants 12 month-old or less, and compared the results with those of 31 control TB infants and children aged 13 to 35 month-old. The frequency distribution of tuberculin skin reaction size among the studied infants was significantly smaller than that among the controls (p < 0.05). MTB was positive among 33 out of the 45 studied infants (73%) while 12 out of the 31 controls (39%), and the difference was significant (p < 0.005). Miliary TB and/or TB meningitis were seen among 8 out of the 45 studied infants (18%) while 1 out of the 31 controls (3%), and there was marginally significant difference between them (p = 0.054). These results suggest that delayed-type hypersensitivity and cell-mediated immunity to MTB among infants 12 month-old or less may be lower than those among infants and children aged 13 to 35 month-old, and the studied infants may be inferior in their capacity to kill mycobacteria and to encapsulate mycobacteria by granuloma formation.

Immunological assessment in patients of leukaemia.

In the present study delayed cutaneous hypersensitivity response (DNCB test) and humoral response (by uantification of immunoglobulins) ware carried out in 20 cases of leukaemias. None of the cases was found to be anergic or immunodeficient. In remission also patients showed the normal response.

Comparison of two methods for the assessment of delayed-type hypersensitivity skin responses in patients with human immunodeficiency virus infection.

We compared two techniques for detecting delayed-type hypersensitivity (DTH) skin responses in 359 patients infected with human immunodeficiency virus (HIV) (mean CD4+ lymphocyte count, 387/microL). DTH responses were assessed with use of two antigenic panels administered simultaneously: tuberculin purified protein derivative (PPD) plus three control antigens (Candida albicans, mumps antigen, and tetanus toxoid) administered by the Mantoux method and by a multiple-puncture device delivering seven antigens percutaneously (MULTITEST CMI; Institut Mérieux, Lyon, France). Eighty-three patients (23%) were anergic, 216 (60%) reacted to both panels, 55 (15%) did not react to MULTITEST CMI but did react to the antigens administered by Mantoux method, and only five (1%) reacted to MULTITEST CMI without reacting to antigens administered by the Mantoux method (P < .001, McNemar's test). Each of the three possible combinations of PPD plus two control antigens administered by the Mantoux method were also superior to MULTITEST CMI for classifying patients as nonanergic (P < .001, McNemar's test). We conclude that the application of antigens by the Mantoux method is more efficient than MULTITEST CMI for detecting DTH skin responses in HIV-infected patients.

Assessment of respiratory hypersensitivity in guinea pigs sensitized to toluene diisocyanate: improvements on analysis of respiratory response.

Groups of guinea pigs of the Hartley strain were sensitized to toluene diisocyanate (TDI) by combined single intradermal injection and repeated inhalation exposure (3 h/day for 5 consecutive days) to 0, 3.8, 11, 26, 46, and 51 mg TDI/m3 air. One group of animals was sensitized by intradermal injection only. Sham-exposed and TDI-polyisocyanate resin-sensitized guinea pigs served as controls. Three weeks after the first encounter with the inducing agent, animals were challenged with the free TDI (approximately 0.5 mg/m3) and 1 week later with TDI-guinea pig serum albumin conjugate. Breathing patterns were analyzed by objective mathematical procedures taking into account the intensity and duration of the respiratory rate exceeding +/- 3 standard deviations of the individual prechallenge exposure period. In none of the animals challenged with TDI were conclusive immediate-onset respiratory responses identified. During the TDI conjugate challenge a characteristic increase in respiratory rate was observed in all groups sensitized with TDI. In each of the sham and TDI-resin control groups, 1 of 16 animals responded mildly to the conjugate challenge. With regard to analysis of the development of asthma-like dyspnea, the results obtained suggest that respiratory response can suitably be defined by objective mathematical analysis of breathing patterns. Moreover, the "duration" of response exceeding +3 x standard deviation of prechallenge baseline data appears to show less variability when compared to the "intensity" of response (area). It can be concluded that this method of evaluation of respiratory response may be useful to compare more quantitatively this type of data and serves the objective of decreasing potential interlaboratory variability.

Effect of selection of swine for high and low immune responsiveness on monocyte superoxide anion production and class II MHC antigen expression.

Monocyte function was investigated in second (G2) and third (G3) generation pigs selected for high and low antibody and cell-mediated immune responsiveness. In groups of pigs from the high-and low-immune response lines, monocyte release of superoxide anion (O2-) was assayed in response to phorbol 12-myristate-13-acetate and expression of the Class II-MHC (MHC-II) antigens SLA-DR and SLA-DQ, determined using flow cytometry. Analysis of variance using a linear model demonstrated no significant intergroup differences in O2- production by lymphokine-activated monocytes from G2 pigs. In G3 pigs, there were no significant intergroup differences in the percentage of MHC-II+ cells or in the density of expression of either SLA-DR or SLA-DQ. In individual pigs, monocyte SLA-DR and SLA-DQ expression was similar in terms of the percentage of MHC-II+ cells and in the magnitude of MHC-II expression. Litter contributed significantly to variation in monocyte O2- production in G2 pigs (P < or = 0.005) and SLA-DQ (P < or = 0.01) expression. Although the lines differed significantly in correlates of antibody and cell-mediated immune response, there was no apparent effect of selection for high and low immune responsiveness in swine on monocyte O2- production and MHC-II expression.

[Immunologic consequences of malnutrition: assessment with multitest]. / Consecuencias inmunológicas de la desnutrición: valoración con multitest.

Presentation of a clinical study of 256 patients eligible for elective surgery, with the purpose of evaluating the immunological consequences of malnutrition. With this aim, retarded hypersensitivity skin tests were performed. The malnutrition criteria used included 10% normal weight loss and/or seric albumin levels of less than 3.5 g/dl. There were 99 patients in total (38.67%) with malnutrition criteria. Within this group 21.79% showed positive responses compared to 38.88% of control group (p less than 0.001). The "average papule" in the group suffering from malnutrition was 4.18 +/- 2.06 and in the control group, 3.64 +/- 2.20 (p less than 0.001), with a significant increase in tuberculine papule in the group with malnutrition.

The immunosuppressive effect of hepatocytes in rats--assessment by heart allograft survival and delayed-type-hypersensitivity reactions.

The immunosuppressive effect of hepatocytes was examined experimentally by heart allograft and delayed-type-hypersensitivity (DTH) reactions. The hepatocyte inoculation (1 X 10(7) of BDE (of the major histocompatibility complex haplotype RT1u), LEW (RT1l), and DA (RT1a) into the spleens of LEW rats significantly prolonged the survival of BDE heart allografts to 14.3 +/- 2.7 (mean +/- SD), 9.2 +/- 0.8, and 10.8 +/- 2.3 days respectively, compared with 6.7 +/- 0.8 days in controls (p less than 0.01). Moreover, the BDE hepatocytes had a significantly prolonged survival compared to the LEW (p less than 0.01) and DA (0.02 less than p less than 0.05) groups. BDE hepatocyte (donor specific) inoculation 4 and 7 days before priming with the spleen cells reduced DTH responses in the LEW rats to 44.6 +/- 4.8 per cent, and 74.2 +/- 8.0 per cent, respectively. DA hepatocyte inoculation (third party) 4 and 7 days prior to priming reduced DTH responses to 72.5 +/- 11.5 per cent, and 76.5 +/- 11.9 per cent, respectively. All DTH responses were significantly suppressed after hepatocyte inoculation compared to 100 per cent in the controls (p less than 0.01). Moreover, the inoculation of BDE hepatocytes (donor specific) 4 days prior to the priming significantly reduced DTH responses compared to the group primed 7 days before (p less than 0.01). From these results we concluded that hepatocytes produced not only non-specific but also donor specific immunosuppressive effects through T cell immune reaction. Moreover, donor specific immunosuppressive effects were induced at least 4 to 7 days after hepatocyte inoculation.

Nutritional status assessment of HIV-positive drug addicts.

Since human immunodeficiency virus (HIV) is known to lead to modifications of immune function and interrelationships among malnutrition, anergy and drug addiction have been shown, the aim of this work was to assess the nutritional status of 36 male heroin addicts under a period of detoxication (3 months). They were divided into two groups: (1) HIV negative (n = 20) and (2) HIV positive (n = 16); heights, weights and serum albumin concentration were measured and immune function was tested, using delayed hypersensitivity skin tests containing 7 antigens. No significant differences in anthropometric measurements were found between both groups, but anthropometric improvement was shown in every patient after the detoxication period. Serum albumin, often used as a classical index of malnutrition, remained within the normal values in both groups. The whole response to skin tests was depressed in both groups and no significant differences were shown between them. Therefore, these results might suggest that in spite of the apparent anthropometric recovery and the normal values of albumin, a subclinical malnutrition was indicated by the depressed immune function, which was more noticeable in the HIV-positive group.