concanavalin-a and Newcastle-Disease

The adjuvant activity of GLP was investigated in vitro and in vivo. In vitro experiment, the effects of GLP on chicken peripheral lymphocytes proliferation were compared by MTT assay. The results showed that GLP could significantly enhance lymphocytes proliferation singly or synergistically with ConA. The interferon-gamma (IFN-γ) mRNA levels of chicken peripheral lymphocytes stimulated by GLP synergistically with ConA were measured using fluorescent quantitative PCR. The results showed that GLP could promote interferon-γ mRNA levels in peripheral lymphocytes. In vivo experiment, 175 14-day-old chickens were randomly divided into 7 groups. The chickens except blank control (BC) group were vaccinated with Newcastle disease vaccine, repeated vaccination at 28 days old. At the same time of the first vaccination, the chickens in experimental groups were orally administrated with 5 different doses of GLP respectively, whereas vaccination control (VC) and BC groups were treated with physiological saline, once a day for three successive days. On Day 7, 14, 21 and 28 after the first vaccination, the peripheral lymphocytes proliferation and serum ND antibody titer were determined. The results showed that GLP could significantly promote lymphocyte proliferation and enhance serum antibody titer. The results indicated that GLP may be a novel immunomodulator.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Viral; Cell Proliferation; Concanavalin A; Drug Synergism; Ganoderma; Gene Expression Regulation; Interferon-gamma; Lymphocytes; Male; Newcastle Disease; Polysaccharides; RNA, Messenger; Viral Vaccines

A competitive liquid-phase-blocking concanavalin A enzyme-linked immunosorbent assay (LPB-ConA-ELISA) was developed in the current study. The assay used ConA as a capture reagent, and the sera of specific pathogen-free chickens immunized with nonpurified Newcastle disease virus (NDV) suspension as detector antibodies, to detect and quantify specific antiviral antibodies in serum samples from free-ranging pigeons. The comparison between the LPB-ConA-ELISA and the hemagglutination inhibition (HI) test for the detection of antibodies in serum samples from 107 pigeons showed significant correlation between the assays (r = 0.875), a high sensitivity (100%), specificity (95.8%), accuracy (96.3%) for the ELISA, and good agreement (κ = 0.83) between the 2 assays. The results of this study suggest that the LPB-ConA-ELISA could be a useful alternative to HI test in the serodiagnosis of NDV in pigeons, or other species of birds.

Topics: Animals; Antibodies, Viral; Chickens; Columbidae; Concanavalin A; Enzyme-Linked Immunosorbent Assay; Hemagglutination Inhibition Tests; Linear Models; Newcastle Disease; Newcastle disease virus; Reproducibility of Results; ROC Curve; Sensitivity and Specificity; Specific Pathogen-Free Organisms

Optimum conditions for in vitro chicken interleukin-2 (IL-2) production were studied. IL-2 containing culture supernatants were generated by mitogen stimulation of splenic mononuclear cells (SMC) and the samples were tested on 72 h Concanavalin A (ConA) blasts for their proliferative ability. 3H-thymidine incorporation was used as a measurement of proliferation. Higher stimulation indices and thus maximal IL-2 production were obtained with the following culture conditions: 5 x 10(6) cells ml(-1) cultured for 24 h in the presence of 10 microg ml(-1) ConA in serum free Iscove's modified Dulbecco medium. The molecule responsible for IL-2 activity was found to have a molecular weight of 14000 as estimated by size exclusion chromatography. SMC obtained from chickens inoculated with Newcastle disease virus were used to study the immunomodulatory role of IL-2. The lymphocyte transformation test was used as an in vitro correlate of cell mediated immunity in these chickens. The mitogen responses of cells obtained from virus inoculated and control chickens were similar on the basis of stimulation indices. Antigen specific lymphocyte proliferation was demonstrated using SMC obtained from virus inoculated chickens. Uptake of exogenous IL-2 by 72 h ConA blasts was of similar magnitude in both virus inoculated and control chickens indicating that uptake of IL-2 by T lymphocytes was normal in Newcastle disease virus inoculated chickens.

Topics: Animals; Chickens; Concanavalin A; In Vitro Techniques; Interleukin-2; Lymphocyte Activation; Lymphocytes; Molecular Weight; Monocytes; Newcastle Disease; Newcastle disease virus; Spleen; Viral Vaccines

Broiler chickens were examined for the effects of low (400 IU/kg), standard (1,500 IU/kg), or high (15,000 IU/kg) dietary vitamin A (VitA) levels on immune responsiveness postimmunization to Newcastle disease virus (NDV). A control pair-fed group (1,500 IU/kg) was included to compensate for the reduced feed intake associated with diet containing the low level of VitA. Interdigital skin reactions to phytohemagglutinin (PHA) and CD4:CD8 T lymphocyte ratios were significantly reduced in chickens fed the low VitA diet, whereas their antibody responses to NDV were significantly increased as compared to birds that consumed the 1,500 to 15,000 VitA diet ad libitum. On the other hand, birds on the high VitA diet had reduced lymphocyte responses to concanavalin A and pokeweed, but not to PHA. No effect of dietary VitA was observed for natural killer activity, nor on levels of percentage of cells expressing Class II MHC antigens among groups that consumed feed ad libitum. The results indicated that both humoral and cellular immune responses were modulated by levels of VitA in the diet, and suggest that VitA-deficient chickens developed a T helper (Th)2 immune response, whereas the chickens fed highly enriched VitA diet showed a Th1 immune response.

Topics: Animals; Antibodies, Viral; Antibody Formation; CD4 Antigens; CD8 Antigens; Chickens; Concanavalin A; Diet; Dose-Response Relationship, Drug; Female; Histocompatibility Antigens Class II; Immunity, Cellular; Killer Cells, Natural; Liver; Lymphocyte Activation; Newcastle Disease; Newcastle disease virus; Organ Size; Phytohemagglutinins; Pokeweed Mitogens; Random Allocation; Spleen; T-Lymphocytes; Vitamin A; Weight Gain

Evidence is presented that interferon (IF) is a major mediator of the human concanavalin A (Con A) suppressor cell. The suppressive effects of Con A-activated lymphocytes on the mitogen responses of normal responder cells were largely abrogated by addition of anti-human leukocyte IF serum. Similar suppressor activity was generated by coculture of peripheral blood leukocytes (PBL) with a melanoma cell line (MeWo) and a HeLa cell line persistently infected with measles virus that induced the production of IF by lymphocytes. A human mammary carcinoma line (MCF-7) and two bladder carcinoma lines (T24 and TCCSUP) failed to induce IF or suppression. Addition of anti-human leukocyte IF serum to suppressor cells and supernates from tumor cell-lymphocyte cocultures largely abolished suppression and neutralized the antiviral activity of such supernates. Exposure of PBL from purified protein derivative (PPD)-positive donors to PPD caused the production of suppressor activity and IF. PBL from PPD-negative donors failed to produce significant amounts of IF or to suppress on exposure to PPD. Supernates from PBL treated with virus (Newcastle disease virus [NDV]) contained IF and suppressed the mitogen responses of responder PBL. Both the suppressive and the antiviral activities of this material were eliminated after treatment with anti-IF serum. To ascertain whether antiviral and suppressive activities were mediated by the same types of IF, supernates from PBL cultured with Con A, PPD, NDV, and tumor cells were treated with anti-IF serum or acid pH. In all cases antiviral activity was neutralized in parallel with abrogation of suppressor activity. These results provide strong evidence for the role of IF as a mediator of human suppressor cell activity.

Topics: Animals; Birds; Cells, Cultured; Concanavalin A; Humans; Immune Tolerance; Interferon Inducers; Interferons; Leukocytes; Lymphocytes; Lymphokines; Neoplasms, Experimental; Newcastle Disease; T-Lymphocytes, Regulatory; Tuberculin