The effect of glutaraldehyde fixation on the immunogenicity of allogeneic lymphoid and tumour cells.

When CBA mice were injected with allogeneic (DBA/2) lymph node cells treated with glutaraldehyde at concentrations of 0.13% and 0.013% they failed to produce a primary cytotoxic antibody response; cells fixed with 0.0013% glutaraldehyde only provoked the slightest of antibody responses. No significant secondary response was provoked by cells fixed with 0.013% glutaraldehyde in mice primed 8 weeks earlier with normal lymphoid cells. As it is well established that such cells can stimulate a secondary mixed lymphocyte reaction and have ben reported to induce a secondary haemagglutinin response their assumed antigenicity in these experiments was checked. It was found that fixed cells did not have measurable antigenicity as assessed by ability to absorb anti-H2 antibody. The organ localization of chromium-labelled glutaraldehyde-fixed lymph node cells showed a lack of localization in lymph nodes at all levels of fixation, though localization in the spleen of cells fixed with 0.0013% glutaraldehyde was very variable, consistent with the borderline immunogenicity of such cells. Mitomycin treatment only modestly reduced the immunogenicity of lymph node cells and did not affect their organ localization. When CBA mice were injected with allogeneic (DBA/2) tumour cells, P 815, fixed with 0.13% or 0.013% glutaraldehyde, no cytotoxic antibody was produced and cells fixed with 0.0013% glutaraldehyde stimulated an erratic low response again suggesting a borderline level of activity. However P 815 cells fixed with 0.13% glutaraldehyde retained their antigenicity as assessed by absorption. Mitomycin treatment of P 815 cells had only a modest deleterious effect of their immunogenicity. These differences in immunogenicity are discussed in relation to the viability of cells required to stimulate an allo-cytotoxic antibody response.