Rosette-forming ability of thymus-derived lymphocytes in cell-mediated immunity. I. Delayed hypersensitivity and in vitro cytotoxicity.

Abstract

Effector cells in delayed hypersensitivity and in vitro cytotoxicity were studied in lymph node cells from animals immunized with sheep erythrocytes (SRBC) in complete Freund's adjuvant. Delayed hypersensitivity response (DHR) was assayed by the increase in foot pad swelling after the intrafoot pad injection of immune cells plus antigen. Cell-mediated cytotoxicity against SRBC was assayed by a microcytotoxicity test with sheep fibroblasts as target cells. Effector cells were antigen specific, sensitive to anti-theta serum plus complement (C), and insensitive to anti-Ig serum plus C. A nonrosette-forming (non-RFC) small lymphocyte effector T cell and a rosette-forming medium lymphocyte effector T cell were isolated by velocity sedimentation. The small lymphocyte non-RFC required a longer time than the medium lymphocyte RFC effector cell to produce maximum activity. Buoyant density failed to distinguish medium lymphocyte effector cells in DHR and in vitro cytotoxicity.

Nylon adherent antigen-specific rosette-forming T cells.

“…It has previously been suggested that some T-RFC function as effector cells for delayed-tape hypersensitivity to sheep erythrocytes (SRBC) (10). Our results indicate that T-RFC belong to a distinct minor subset of T cells which adhere to nylon wool.…”

“…It is also possible that since a significant number of Fc positive T cells adhere to nylon (21) that the antigen-specific molecule is not necessarily made by the T-RFC but is demonstrable only on the cells which receive it passively. This could explain why it has been so difficult to demonstrate antigen-binding helper cells (10). They may shed or secrete their receptors too rapidly or too easily to be detected, while only the cells which passively pick up these factors or receptors can be demonstrated by antigen binding.…”

H‐2 Restricted Cytolytic and Noncytolytic T Cell Clones: Isolation, Specificity and Functional Analysis

“…Brondz et al (1973) found that cytotoxic T cells specific for allogeneic cells did not form rosettes after overnight incubation at 4'^C with red cells carrying or coupled with the appropriate alloantigens. In contrast, Elliott et al (1975) could form specific rosettes with sheep red cells and murine T cells with lytic activity for sheep fibroblasts. Elliott & Haskill (1973) found that T rosettes were unstable and indicated various procedures to prevent the dissociation of indicator red cells from the T celis.…”

The nature of allorosette-forming cells in rats

“…In other experiments, T cells forming rosettes with sheep red blood cells exhibit helper cell function [3,23,37]. Also, delayed type hypersensitivity and in vitro cytotoxicity are contributed to rosette forming T cells [12]. Experiments performed in the allogenic mouse system failed to detect allorosette forming cytotoxic T cells, but there was no rosetteinhibition by anti-0 antibodies, indicating the lack of T-rosettes [7].…”