CD79a activation on myeloid cells affects migration, differentiation and T-cell suppression.

<p>(A) The effect of stimulation with anti CD79a(v-20) on the migration of FACS-sorted Ly6C+ immature myeloid cells from naive bone marrow was tested in a Transwell® system for 48 h. Results are mean +/− SEM; n = 3 determinations. (B) Bone marrow cells from naïve SCID mice were stimulated with anti- CD79a(v-20) (5 µg/ml) for 96 h with or without added GM-CSF in low (2%) normal mouse serum. The effect of anti CD79a(v-20) on myeloid cell differentiation status was assessed using immature myeloid (CD11b⁺Gr1⁺), granulocytic (Gr1⁺) and macrophage (F4/80⁺) markers. Data shown are representative of two independent experiments. (C) The effect of immature myeloid cells stimulated with anti CD79a on proliferation of CD4 T cells. Immunopurified naïve CD4+ T cells (“T”) labeled with CSFE were stimulated with anti CD3/CD28 with the addition of the indicated ratios of FACS-sorted immature BM myeloid cells (“M”) with or without the addition of anti CD79a(v-20) antibody. Cell divisions were measured by flow cytometry analysis for CFSE dilution. Dose response for effect on T-cell division of myeloid cells added at the indicated ratio, with the addition of anti CD79a(v-20) or isotype-matched control antibody is shown. (D) The effect of LLC tumor cell conditioned medium (CM) (ratio 1/5 v/v), myeloid cells and the combination of both on T cells proliferation. Data shown are representative of two independent experiments.