Immunoglobulin Fraction Of Antiserum Research Articles

Autocrine growth induced by src-related oncogenes in transformed chicken myeloid cells

Chicken myeloid cells transformed by the v-myb- or v-myc-containing leukemia viruses, E26 and OK10, respectively, require chicken myelomonocytic growth factor (cMGF) for proliferation in vitro. Upon superinfection with retroviruses carrying oncogenes of the src gene family, these myeloid cells acquire the ability to grow in the absence of exogenous cMGF. Conditioned medium prepared from superinfected E26 cells contains a growth-stimulating activity similar in biological and immunological properties to cMGF. This activity is reduced by more than 80% following absorption of conditioned media with antiserum against cMGF. Incubation of superinfected E26 cells with an immunoglobulin fraction of antiserum against cMGF inhibits their proliferation, indicating that the cells are dependent on the secreted factor. We conclude that viral oncogenes of the src family can induce chicken myeloid cells to produce a cMGF-like factor(s) that stimulates proliferation of these cells in an autocrine fashion.

Anti-influenza response achieved by immunization with a synthetic conjugate.

The peptide corresponding to sequence 91--108 of the hemagglutinin of type A H3N2 influenza virus has been synthesized by the solid-phase peptide synthesis method and covalently attached to several macromolecular carriers. The conjugate with tetanus toxoid was used for immunization of rabbits and mice. The immunoglobulin fraction of the rabbit antiserum showed the presence and antipeptide antibodies by both agar gel diffusion and radioimmunoassay. In the latter assay, the antibodies showed marked crossreactivity with the intact virus of the A/Texas/77 strain. The antibodies were also capable of inhibiting the hemagglutination of chicken erythrocytes by the virus; the highest hemagglutination inhibition titer (1:32) was achieved with a serum-resistant strain of A/Texas/77. When the in vitro virus plaque formation assay was used with monolayers of Madin--Darby canine kidney (MDCK) cells, the number of plaques was reduced on interaction with the immunoglobulin fraction of the antiserum, which was effective up to a dilution of 1:32. Preliminary results indicate that C3H/DiSn mice immunized with the peptide--tetanus toxoid conjugate are partially protected against a further challenge with A/Texas mouse-adapted influenza virus. The results are thus indicative of the efficacy of the synthetic material in eliciting anti-influenza immune response.