Labeling Studies on Lymphocytes

Abstract

A number of SEM studies of labeled human and murine lymphocytes have been reported recently [32, 38, 47, 48, 55, 56] using hybrid antibody techniques which employ tobacco mosaic virus (TMV) or latex spheres as markers. In these studies, lymphocytes were seen to have varying numbers of microvilli and almost no cells with ruffles were labeled. When cells were labeled with antitheta (Θ) antibody and TMV, the hybrid antibody attached predominantly to cells with few microvilli while the hybrid antibody prepared against B-cells attached mostly, but not in all cases, to villous cells [32] and quite frequently to microvilli. Similar results were described by Lipscomb et al. [48] in their study. However, labeled overlapping populations were seen in the above studies and in those of Nemanic [56], Molday [55] and coworkers and Linthicum and Sell [47], and it was not possible to distinguish different subpopulations on the basis of these results. However, it does appear that the surface immunoglobulin is located in nonrandom areas [47, 48], frequently on the microvilli [47] and not on the smoother portions of the cell. Most of the above studies employed one marker which restricted visualization to only one type of receptor.