Objective:To investigate if a plant-derived polysaccharide sulfate(M33A) binding to HIV1 gp120 may induce the exposure of neutralization epitopes of gp120,and if M33A-bound HIV-1ⅢB antigens may be used as a AIDS vaccine for inducing neutralizing antibodies against HIV-1.Methods:Whole-inactivated M33A-bound HIV-1ⅢB antigens were prepared and used to immunize mice after mixing with FCA or FIA.The titers of anti-HIV-1 IgG antibodies in immunized mouse plasma were detected by ELISA,and the HIV-1 neutralization by those plasma was detected by the improved microtiter neutralization assay.Results:M33A-bound HIV-1 antigens induced higher titers of anti-HIV-1 IgG antibodies(group C:1.5?10~6;group D:1.5?10~6) than HIV-1 antigens alone(4.9?10~5),and female mice produced 3 times higher titers of anti-HIV-1 IgG antibodies than male mice after immunized with various HIV-1 antigens.All three immunization schemes did not induce the production of anti-HIV-1 neutralizing antibodies.Conclusion:M33A binding does not induce gp120 to expose neutralization epitopes.However,M33A may improve the level of mice immune responses to HIV-1 antigens,suggesting M33A may enhance immune response to HIV-1 antigens.

The levels of IgG2b monoclonal antibodies against LD H-C4 in sera of mice bearing hybridoma backpack tumors secreting anti-LDH-C4-IgG2b were detected by quantitative ELISA． The accuracy between batches is 7.04%～l3.30 %, the intra-assay variation is 3.6l%～l0.20%． Standard curveof monoclonal lgG2b was well correlated (r=0.962　　884～0.996　　795)． The sensitivit y of the assay reach e dup to0.0l?mg/L． The present modified ELISA offers a reproducible, se nsitive, specific method in determination of antigen-specific IgG2b antibody in sera．

OBJECTIVETo study anti-HIV activity and mechanism of Cynanchum otophyllum glucan sulfate in vitro.

METHODAnti-HIV-1 activity was detected with syncytial formation assay and quantitative P24 enzyme-linked immunosorbent assay (ELISA); cytotoxicity was tested with MTT colorimetric assay. Antiviral mechanism was investigated by fusion inhibition, time of addition and pre-treatment experiments.

RESULTThe 50% inhibition concentrations (IC50) of PS20 for HIV-1(IIIB), HIV-1(Ada-M), and HIV-1(Bal), were 0.26, 0.46, 0.90 micromol x L(-1), respectively. Studies on antiviral mechanism of PS20 showed that target molecule may be viral envelope protein.

CONCLUSIONThe results suggested that PS20 had high anti-HIV activity and was worth to be studied further.

Anti-HIV Agents ; pharmacology ; Cell Fusion ; Cell Line ; Cell Proliferation ; drug effects ; Cynanchum ; chemistry ; Glucans ; isolation & purification ; pharmacology ; HIV-1 ; drug effects ; Humans ; Inhibitory Concentration 50 ; Plant Extracts ; pharmacology ; Plant Roots ; chemistry ; metabolism ; Viral Envelope Proteins ; drug effects