T1 and T2 lymphocytes in primary and secondary delayed type hypersensitivity of mice. I. Contribution in the response to sheep red blood cells and to allogeneic spleen cells

MHC- and Igh-unrestricted interaction between L3T4+, Lyt-2- Ts inducer cells and L3T4-, Lyt-2+ Ts effector cells is required for T cell-dependent suppression of DTH to histocompatibility antigens

This paper describes the characteristics of T suppressor inducer (Ts ind) cells which can interact with T suppressor effector (Ts eff) cells and thereby can account for suppression of delayed-type hypersensitivity (DTH) to alloantigens. Adoptive transfer of spleen cells from mice intravenously (i.v.) injected with allogeneic spleen cells one day earlier induced an antigen-specific state of suppression in the recipients. This became apparent when DTH was induced by subcutaneous (s.c.) immunization of the recipients three days after transfer. The induction of suppression after adoptive transfer of spleen cells required Thy-1+, L3T4+, Lyt-1+2- cells. These cells that by themselves did not exert a suppressive effect induced a state of suppression in recipient mice by activation of recipient-type Ts eff cells. Therefore, the former cell type was classified as Ts ind cell. When athymic nude mice were used as recipients, Lyt-2+ precursors of Ts eff cells had to be transferred together with the Ts ind cells to induce a state of suppression in these mice. The Ts ind cells could activate Ts eff cells in MHC- and Igh-incompatible recipients. The results are discussed in relation to previously described immunoregulatory T cell pathways.

Suppression of antigraft immunity by preimmunization. V. Characterization of suppressor T memory cells

We have previously shown that after intravenous (i.v.) immunization of mice with allogeneic spleen cells, two populations of suppressor T (Ts) cells may occur that can suppress delayed-type hypersensitivity (DTH) to alloantigens: Ts effector cells that transiently occur in the spleen, and long-lived, recirculating Ts cells that occur in thoracic duct lymph and can be transferred by parabiosis. In this study, we investigated whether the latter Ts cells fulfill the criteria for memory T lymphocytes, such as induction by doses of antigen lower than required for T effector cell induction, accelerated onset of activity after reactivation and an increased activity as compared with virgin T cells. The Ts cells accounting for the long-lasting state of suppression of DTH to alloantigens indeed fulfilled these criteria. These Ts memory cells displayed the Thy-1+, L3T4-, Lyt-1+2+ phenotype.

Lipopolysaccharide-induced suppression of graft-versus-host reactivity in mice

Reconstitution of lethally irradiated mice with spleen cells from donors that had been treated with lipopolysaccharide (LPS) intravenously and allogeneic spleen cells subcutaneously leads to a suppressed anti-host delayed-type hypersensitivity (DTH). Either donor injection alone proved to be ineffective. The state of suppression appeared to be antigen-specific, but, depending on the experimental conditions, also anti-host DTH to third-party alloantigens could be suppressed. The suppression was mediated by a population of Thy-1- suppressor cells that could also be induced in athymic nude mice. The suppressor cells specifically adhered to anti-kappa-coated plastic plates, but were not adsorbed by passage through a Sephadex G-10 column. Thus, it appears that the combined donor treatment with LPS and allogeneic spleen cells induces a population of B cells that can suppress anti-host immune reactivity.

Generation of suppressor T cells after local immunization with histocompatibility antigens

Subcutaneous (sc) hind-foot immunization (HFI) of mice with allogeneic spleen cells can induce a state of delayed-type hypersensitivity (DTH) as well as a state of suppression of DTH. This paper deals with the suppression induced by HFI. The state of suppression could be adoptively transferred by spleen cells and lymph node cells between Days 3 and 7 after HFI only. However, in the hind-foot-immunized mice the state of suppression lasted at least 25 days. The suppressor cells expressed the Thy-1+, Lyt-1-2+ phenotype and suppressed DTH antigen-specifically. The suppressor cells, however, also suppressed DTH responses to unrelated third-party alloantigens, provided the latter were administered during the induction of DTH together with the same alloantigens that were used for HFI. The HFI-induced T-suppressor cells suppressed the induction phase of DTH (i.e., the proliferative activity of the draining lymph node cells after secondary sc immunization), but not the expression phase of DTH (i.e., the activity of previously activated DTH effector T cells). H-2D compatibility between the donors of the HFI-induced T-suppressor cells and the recipients was required for the adoptive transfer of suppression. The differences in effect of local immunization versus systemic immunization on the induction and functional activity of T-suppressor cells are discussed.

Lipopolysaccharide-induced suppression of DTH-reactivity to histocompatibility antigens. I. Kinetic aspects and specificity

The effects of bacterial lipopolysaccharide (LPS) on the development of DTH-reactivity to alloantigens in mice were investigated. DTH to a particular set of alloantigens could be suppressed by treatment of responder mice with a single intravenous (i.v.) injection of 100 micrograms LPS and a simultaneous subcutaneous (s.c.) injection of the appropriate allogeneic spleen cells. The suppression lasted at least 60 days and affected the afferent limb of the DTH response as well as the efferent limb. The suppression could be adoptively transferred to naive syngeneic recipient mice by spleen cells, but not by immune serum, and proved to be antigen-specific. In spite of this specificity, the DTH-response against unrelated "third-party" alloantigens could be suppressed as well, provided the latter were presented during the induction-phase of DTH together with the alloantigens that had been used for the induction of suppression.

Differential influence of 2'-deoxyguanosine on the induction and expression of suppressor T lymphocytes in vivo

Subcutaneous (sc) immunization of mice with allogeneic spleen cells can induce delayed-type hypersensitivity (DTH) to histocompatibility antigens. Intravenous immunization with irradiated allogeneic spleen cells, on the other hand, induces suppressor T (Ts) lymphocytes. These Ts cells are capable of suppressing the host-versus-graft (HvG) DTH reactivity which normally arises after sc immunization. Moreover they can suppress the development of antihost DTH effector T cells during graft-versus-host (GvH) reactions. These models for HvG and GvH DTH reactivity were used to study the influence of 2'-deoxyguanosine (dGuo) on the induction, further development, and expression of Ts cells in vivo. It was found that administration of dGuo inhibits the proliferation-dependent induction and further development of Ts cells, but not the suppression mediated by already activated Ts cells.

Restricted recognition of H-2 subregion coded alloantigens in delayed-type hypersensitivity

Subcutaneous (sc) immunization of mice with H-2K, I, or D incompatible spleen cells induces a state of host-versus-graft (HvG) delayed-type hypersensitivity (DTH). The DTH reaction is elicited by challenging the immunized mice in a hind foot with similar allogeneic spleen cells and is measured as the subsequent foot swelling. DTH effector T cells specific for H-2I-coded alloantigens, but not for H-2K/D-coded alloantigens, can be induced in a graft-versus-host (GvH) model as well. In this paper we report that under HvG as well as under GvH conditions the recognition of class II antigens by DTH effector T cells is restricted by class I molecules. Furthermore, DTH effector T cells induced by sc immunization with class I antigens appear to be restricted by class II molecules.