Cell-to-Cell Interaction in the Immune Response

Abstract

Experiments were designed to test the possibility that thymus-derived (T) cells cooperate with nonthymus derived (B) cells in antibody responses by acting as passive carriers of antigen. Thoracic duct lymphocytes (TDL) from fowl γG-tolerant mice were incubated in vitro with fowl anti-mouse lymphocyte globulin (FALG), which was shown not to be immunosuppressive in mice. On transfer into adult thymectomized, irradiated, and marrow protected (TxBM) hosts together with a control antigen, horse RBC, a response to horse RBC but not to fowl γG was obtained. By contrast, TxBM recipients of nontolerant, FALG-coated TDL responded to both antigens and the antibody-forming cells were shown to be derived from the host, not from the injected TDL. These findings suggested that, under the conditions of the experiment, triggering of unprimed B cells in the spleens of TxBM hosts was not achieved with antigen-coated tolerant lymphocytes. Another model utilized the ability of B cells to bind antibody-antigen complexes. Spleen cells from TxBM mice, incubated in vitro with anti-fowl γG-fowl γG·NIP, were injected with or without normal TDL (a source of T cells) into irradiated hosts. Only mice given both cell types could produce an anti-NIP antibody response. In a further experiment, spleen cells from HGG·NIP-primed mice were injected together with NIP-coated B cells (prepared as above) into irradiated hosts. A substantial anti-NIP antibody response occurred. If, however, the T cells in the spleens of HGG·NIP-primed mice were eliminated by treatment with anti-θ serum and complement, the NIP response was abolished. It was concluded that antigen-coated B cells could not substitute for T cells either in the primary or secondary response. Treatment of T cells from unprimed or primed mice with mitomycin C impaired their capacity to collaborate with B cells on transfer into irradiated hosts. Taken together these findings suggest that before collaboration can take place T cells must be activated by antigen to differentiate and in so doing may produce some factor essential for triggering of B cells.

Cell-to-Cell Interaction in the Immune Response

“…These findings are in general agreement with our previous results on mitomycin C sensitivity of T cells from unprimed or primed mice (13). They must, however, be reconciled with reports that heavily irradiated lymphoid cells retained helper activity in vivo (2) or in vitro (3,14,15).…”

“…TDL from CBA mice, primed to FTG 5 months before, were exposed to 1000 rads in vitro and various cell numbers injected intravenously into irradiated (800 fads) recipients together with anti-0 serum-treated spleen cells from CBA mice primed to NNP.OVA 6 wk before. Anti-0 serum was used to abrogate any possible overriding of the carrier effect, a phenomenon previously shown to be dependent on the existence of T cells in the spleens of the hapten-primed mice (13). The irradiated recipients were challenged with NNP.F~/G and their PFC responses to both FTG and NNP were determined 7 days later.…”

Relationship between Fc receptors, antigen-binding sites on T and B cells, and H-2 complex-associated determinants.

“…(b) An Fc receptor-bearing cell would achieve the same effect by binding antigen complexed with antibody . Indeed there is evidence for a role of B cells (25) and macrophages (26) in enhancing T-cell activation in the presence of antibody . (c) The existence on the macrophage of a receptor for T cells (27) provides an alternative method by which macrophages, in the absence of antibody, could effectively present antigen to T cells.…”

Cell-to-Cell Interaction in the Immune Response

“…Thoracic duct lymphocytes (TDL) and spleen cells were collected 6-12 days later since preliminary experiments had indicated that donors were tolerant at that time. The second method of tolerance induction utilized the cyclophosphamide technique (18). Each mouse received an intraperitoneal injection of 5 mg alumprecipitated FTG (FTGA) and 2 X 109 killed pertussis organisms, followed the next day by a 1 Abbreviations used in this paper: DRBC, donkey erythrocytes; FBS, fetal bovine serum; FTG, fowl immunoglobulin G; FTGA , alum precipitated FTG; HRBC, horse erythrocytes; PFC, plaque-forming cells; 19S PFC, direct plaque-forming cells; 7S PFC, redirect (developed) plaque-forming cells; SRBC, sheep erythrocytes; TDL, thoracic duct lymphocytes.…”