Specific Partial Depletion of Graft-vs-Host Activity by Incubation and Centrifugation of Mouse Spleen Cells on Allogeneic Spleen Cell Monolayers

Abstract

Spleen cells (from BALB/c mice immunized with the C57BL/6 lymphoma EL4, or from non-immune BALB/c) were incubated on monolayers of [C57BL/6 × BALB/cF₁ (B₆CF₁) spleen cells on polylysine-coated polystyrene Petri plate, for ½ hr or for 1 hr at 37°C followed by centrifugation of the monolayers for 5 min at 70 × G to 110 × G at 34 to 37°C. Control monolayers were BALB/c spleen cells. As measured by the Simonsen spleen weight assay in neonatal mice, graft-vs-host (GVH) activity was partially depleted in cell populations nonadherent to B₆CF₁ monolayers. Residual GVH activity of these nonadherent cells was about half that of cells incubated on the control syngeneic monolayers (the mean of eight experiments was 49% ± 11% S.D.). Two or three consecutive cycles of incubation and centrifugation did not significantly diminish the residual GVH activity, suggesting that spleen cells with GVH activity are heterogeneous with respect to binding to allogeneic target cells under the above conditions. Cell populations nonadherent to third-part [A × AL]F₁ monolayers retained full activity, and cell populations partially depleted of GVH activity in B₆CF₁ neonates had full activity in third-party [BALB/c × AL]F₁ neonates.