Functional Analysis of B--L (la-Like) Antigen- Bearing Chicken Peripheral Blood Cells.

The function of B-L (Ia-equivalent)-positive (B-L⁺) and -negative (B-L^-) chicken peripheral blood lymphocytes (PBL) was studied in vitro and in vivo. The PBL were first stained in direct immunofluorescence tests with a fluorescein isothiocyanate-labelled anti-B-L alloantiserum and then separated by means of a fluorescence-activated cell sorter. In agreement with our previous findings, B-L^- cells showed functional properties of T lymphocytes, responding to concanavalin A and phytohaemagglutinin-P in vitro and inducing a graft-versus-host (GVH) reaction when injected into allogeneic embryos. Sorted B-L⁺" gave no responses in any of these assays. Neither B-L⁺ nor B-L^- cells, when tested alone, responded significantly to pokeweed mitogen, but mixtures of the two restored the responsiveness to that of the original unsorted suspension. Of the B-L⁺ PBL, 10% were T cells, which may account for the low GVH reactivity given by this population. [ABSTRACT FROM AUTHOR]