Transfer of responsiveness to hapten conjugates of poly-L-lysine and of a copolymer of L-glutamic acid and L-lysine to lethally irradiated nonresponder guinea pigs by bone marrow or lymph node and spleen cells from responder guinea pigs

Induction of susceptibility to HgCl2 immune glomerulonephritis in the Lewis rat by immunocompetent cells from susceptible F1 hybrids

Susceptibility to HgCl2-induced glomerulonephritis was transferred to resistant Lewis (LEW) rats, irradiated and reconstituted with (LEW X BN)F1 hybrid immunocompetent cells. This glomerulonephritis was similar to that observed in Brown-Norway (BN) rats with a first stage characterized by anti-glomerular basement membrane antibodies and a second stage with immune complex-type deposits in the glomerular tufts and in the small renal arteries.

Alloantiserum-mediated suppression of histocompatibility-linked Ir-gene-controlled immune responses. Suppressive effects of IgG fragments derived from alloantisera

Fab, Fc, and F(ab)'(2) fragments were prepared by enzymatic hydrolysis of the IgG fraction of strain 13 antistrain 2 alloantisera. These fragments were not cytotoxic to lymphocytes bearing strain 2 histocompatibility antigens, but the Fab and F(ab)'(2) fragments retained functional combining sites as indicated by their ability to suppress the cytotoxicity mediated by the intact antistrain 2 antibodies. The F(ab)'(2) fragments were much more efficient as inhibitors in this system than the Fab fragments. F(ab)'(2) at 0.06 mg/ml and 0.45 mg/ml Fab produced comparable degrees of suppression. The F(ab)'(2) at 0.06 mg/ml completely suppressed DNP copolymer of L-glutamic acid and L-lysine (GL)-stimulated tritiated thymidine incorporation. The monovalent Fab at 0.45 mg/ml, however, had no significant effect on the in vitro responses to DNP-GL. Addition of the intact alloantisera can be delayed 3 h after initiation of the antigen-stimulated cultures with no loss of suppression. After a delay of 6 h 45% suppression was observed. The requirement for the divalent molecule and the observation that effective suppression of the in vitro responses is still obtained when the alloantiserum is added several hours after initiation of the cultures both suggest that the immunosuppression results from an active process affecting the lymphocyte membrane that renders the cell refractory to the antigenic stimulus.

Function of macrophages in antigen recognition by guinea pig T lymphocytes. II. Role of the macrophage in the regulation of genetic control of the immune response

A number of recent studies have suggested that the main functional role of the product of the immune response (Ir) genes is in the process of antigen recognition by the T lymphocyte. The observation in the accompanying report that the interaction of macrophage-associated antigen with immune T lymphocytes requires that both cells share histocompatibility antigens raised the question as to whether the macrophage played a role in the genetic control of the immune response or even if the macrophage were the primary cell in which the product of the Ir gene is expressed. In the current study, parental macrophages were pulsed with an antigen, the response to which is controlled by an Ir gene lacking in that parent; these macrophages were then mixed with T cells derived from the (nonresponder x responder)F(1) and the resultant stimulation was measured. No stimulation was seen when column-purified F(1) lymph node lymphocytes were mixed with antigen-pulsed macrophages from the nonresponder parent. However, when the highly reactive peritoneal exudate lymphocyte population was used as the indicator cells, parental macrophages pulsed with an antigen whose Ir gene they lacked were capable of initiating F(1) T-cell proliferation. The magnitude of stimulation was approximately 1/10 that seen when macrophages from either the responder parent or the F(1) were used. In order to explain this observation, we hypothesize that antigen recognition sites on the T lymphocyte are physically related to a macrophage-binding site and both are linked to the serologically determined histocompatibility antigens. Thus, parental macrophages pulsed with an antigen, whose Ir gene they lack, activate F(1) cells poorly because the recognition sites for the antigen are physically related to the macrophage-binding site of the responder parent while the main contacts between the cells are at the nonresponder binding sites. Experiments performed with alloantisera lend support to this hypothesis. Thus, when parental macrophages are pulsed with any antigen and added to F(1) T cells, an alloantiserum directed against parental histocompatibility antigens reacts with both the lymphocyte and the macrophage and thereby inhibits macrophage-lymphocyte interaction and abolishes antigen-induced lymphocyte transformation. When the alloantisera are directed at determinants present solely on the T lymphocyte, they only inhibit the recognition of antigens controlled by the Ir gene linked to the histocompatibility antigen against which they are directed. We conclude from these studies that antigen recognition by the T lymphocyte is a complex multicellular event involving more than simple antigen binding to a specific lymphocyte receptor.

Contribution of different cell types to the genetic control of immune responses as a function of the chemical nature of the polymeric side chains (poly-L-prolyl and poly-DL-alanyl) of synthetic immunogens

Genetic regulation of immunological responsiveness was studied at the cellular level by comparing the limiting dilutions of immunocompetent cells from spleen, thymus, and bone marrow of high and low responders as a function of the poly-L-prolyl and poly-DL-alanyl side chains of two synthetic polypeptide immunogens. The spleens of immunized and unimmunized high responder DBA/1 mice were found to contain respectively, 18- and 7-fold more limiting precursor cells specific for (Phe, G)-A--L than the spleens of SJL low responder donors. These results, using a synthetic polypeptide built on multichain poly-DL-alanine, confirm the findings reported for polypeptides built on multichain poly-L-proline (1, 2), that there is a direct correlation between immune response potential and the relative number of immunocompetent precursors stimulated. Cell cooperation between thymocytes and bone marrow cells was demonstrated for both (T, G)-Pro--L and (Phe, G)-A--L. Limiting dilutions of thymus and bone marrow cells in the presence of an excess amount of the complementary cell type indicated an eightfold lower number of detected (T, G)-Pro--L-specific precursors in DBA/1 (low responder) marrow when compared with SJL (high responder) marrow. No differences were observed in the frequency of relevant high and low responder thymocytes for the (T, G)-Pro--L immunogen. These results are similar to those reported for the (Phe, G)-Pro--L (3). In contrast to the cellular studies reported for the Pro--L series of immunogens, the marrow and thymus cell dilution experiments for (Phe, G)-A--L revealed genetically associated differences in both the marrow and thymus populations of immunocytes from high (DBA/1) and low (SJL) responders. In addition to a fivefold difference in limiting marrow cell precursors (similar to that seen in the Pro--L studies), a striking difference was observed between the helper cell activity of high responder DBA/1 and low responder SJL thymocytes. This difference was indicated by the observation that low responder thymocyte dilutions followed the predictions of the Poisson model, whereas dilutions of high responder thymocytes did not conform to Poisson statistics. Transfers of allogeneic thymus and marrow cell mixtures from DBA/1 and SJL donors confirmed the syngeneic dilution studies showing that the genetic defect of immune responsiveness to (Phe, G)-A--L is expressed at both the thymus and marrow immunocompetent cell level. The parameters presently known for genetic control of immune responses specific for (Phe, G) (Ir-1 gene) and for Pro--L (Ir-3 gene) have been compared. The Ir-1 and Ir-3 genes are not only distinct by genetic linkage tests (to H-2) (5, 6, 9), but they are also seen to be different by cellular studies. Furthermore, expression of low responsiveness within a given cell population was shown to depend on the chemical structure of the whole immunogenic macromolecule.

Specific immune response genes of the guinea pig. V. Influence of the GA and GT immune response genes on the specificity of cellular and humoral immune responses to a terpolymer of L-glutamic acid, L-alanine, and L-tyrosine

The ability of guinea pigs to make immune responses to the random linear copolymer of L-glutamic acid and L-alanine, GA, and to L-glutamic acid and L-tyrosine, GT, is each controlled by a different immune response gene. On the other hand, the random linear terpolymer of L-glutamic acid, L-alanine, and L-tyrosine, GAT, which contains both GA and GT antigenic determinants, is immunogenic in all guinea pigs. After GAT immunization, all animals develop delayed hvpersensitivity and serum antibody specific for GAT. However, only those guinea pigs possessing the GA immune response gene demonstrate cross-reactive delayed hypersensitivity when challenged with GA. In addition, the anti-GAT antisera produced by those animals having the GA gene contain cross-reacting anti-GA antibodies. The sera from guinea pigs lacking the GA gene have no anti-GA antibody activity. Thus, we have demonstrated that a specific immune response gene controlling responsiveness to a "simple" antigen can determine the specificity of both cellular and humoral immune responses to a more complex antigen.

The role of thymus and bone marrow cells in delayed hypersensitivity

Adoptive transfer experiments were performed to define the immunological role of thymus and bone marrow cells in the induction of delayed hypersensitivity (DH). The results indicated the following, (a) Bone marrow from immune donors contained cells capable of being stimulated by antigen to initiate the expression of DH. (b) Bone marrow from nonimmune or tolerant donors contained cells that were needed to complete the expression of DH after the infusion of immune lymph node cells. (c) Normal bone marrow and thymus cells cooperated in the irradiated recipient to induce the most vigorous skin reactions to specific antigen; these reactions were seen only when the recipients were stimulated by antigen. Either cell type alone was ineffective. (d) In the presence of tolerant bone marrow cells, thymus cells from immune donors gave a more vigorous response than did thymus cells from normal or tolerant donors. (e) There was suggestive evidence that thymus cells were the source of trigger elements that initiated DH. (f) Antigen in the irradiated recipient was necessary to induce DH after infusion of bone marrow cells alone, or bone marrow and thymus cells together.

Contribution of bone marrow cells and lack of expression of thymocytes in genetic controls of immune responses for two immunopotent regions within poly-(Phe,Glu)-poly-Pro--poly-Lys in inbred mouse strains

Previous cellular studies on the genetic regulation of immunological responsiveness for two immunopotent regions within the branched chain synthetic polypeptide (Phe, G)-Pro--L demonstrated a direct correlation between the number of detectable immunocompetent splenic precursor cells and the response patterns of SJL, DBA/1, and F(1) mice (21). In order to establish the cellular origin(s) of the genetic defect, the present study first demonstrated that thymus and bone marrow cell cooperation was required for (Phe, G)- and Pro--L-specific immune responses. Secondly, limiting dilution experiments, in which several graded and limiting inocula of marrow cells were mixed with a non-limiting number of 10(8) thymocytes and injected into irradiated, syngeneic recipients, indicated that the low responsiveness of the SJL and DBA/1 strains to the (Phe, G) and Pro--L specificities, respectively, could be attributed to a reduced number of precursor cells found in bone marrow. About five times more marrow precursors were detected in SJL mice for Pro--L than for (Phe, G), whereas about five times as many precursor cells were estimated for (Phe, G) as for Pro--L in the DBA/1 strain. These differences are similar to those obtained using spleen cells from unimmunized SJL and DBA/1 donors (21), and indicate that these genetically determined variations in responsiveness can be accounted for by differences in the frequencies of monospecific populations of immunocompetent cells present in bone marrow. In contrast, limiting dilution transfers of thymocytes or thymus-derived cells with an excess of syngeneic marrow cells resulted in equally frequent (Phe, G) and Pro--L responses for both SJL ad DBA/1 strains. This finding in conjunction with the observation that the generation of (Phe, G)- and Pro--L-specific responses were associated in individual recipients injected with limiting inocula of thymocytes indicated that a single population of thymocytes was stimulated by (Phe,G)-Pro--L. Therefore, it is improbable that the thymic population of immunocompetent cells contributes to expression of these genetically controlled defects.

Cellular basis of the genetic control of immune responses to synthetic polypeptides. II. Frequency of immunocompetent precursors specific for two distinct regions within (Phe, G)-Pro--L, a synthetic polypeptide derived from multichain polyproline, in inbred mouse strains

DBA/1 mice are high responders to the (Phe, G) determinant of the synthetic polypeptide (Phe, G)-Pro--L, whereas SJL mice respond well to the Pro--L region of this macromolecule (6). In order to determine whether the phenomenon described above is related to the number of antigen-sensitive units detected for both specificities, and whether responses to these determinants can be transferred independently, graded and limiting inocula of spleen cells from SJL, DBA/1, and F(1) donors were injected into X-irradiated, syngeneic, recipient mice with (Phe, G)-Pro--L. By this approach, one antigen-sensitive unit specific for (Phe, G) was detected in 1.7 x 10(6) and 8.5 x 10(6) spleen cells from immunized and nonimmunized DBA/1 donors, respectively. In contrast, one (Phe, G) relevant precursor was detected in 20 x 10(6) SJL spleen cells, irrespective of whether the donors had been immunized. On the other hand, for the Pro--L specificity, one limiting splenic precursor was found in 1.3 x 10(6) and in 3.4 x 10(6) cells for immunized and nonimmunized SJL donors, respectively; whereas one response unit was estimated for this determinant in 9.4 x 10(6) and in 38 x 10(6) spleen cells from immunized and nonimmunized DBA/1 mice. The findings reported here indicate that the phenotypic expression of the genetic control(s) for immune responsiveness to different immunopotent regions of (Phe, G)-Pro--L is directly correlated with the number of immunocompetent response units detected in two inbred mouse strains. In the spleens of immunized F(1) donors, similar frequencies of one limiting precursor in 3.0 x 10(6) and in 2.8 x 10(6) cells were detected for (Phe, G) and Pro--L, respectively. The results of a chi-square test for independence of (Phe, G) and Pro--L responses in F(1) animals is compatible with the hypothesis that the transferred spleen cells limiting the response to (Phe, G)-Pro--L are restricted to generate antibodies specific for only one of the two determinants of this macromolecule.

Cutaneous basophil hypersensitivity. II. A light and electron microscopic description

Delayed onset erythematous skin reactions elicited in guinea pigs early in the course of sensitization with azobenzenearsonate-protein conjugates or with protein antigens in incomplete Freund's adjuvant or in saline were found to have a characteristic morphology which sets them apart from delayed hypersensitivity and the classic antibody mediated reactions. The principle feature was massive dermal infiltration with basophilic leukocytes. Mononuclear cells of several types including activated and small lymphocytes, monocytes, macrophages, and blast cells were also present. Such reactions have in the past been designated Jones-Mote hypersensitivity, but we prefer the descriptive term cutaneous basophil hypersensitivity (CBH) for the reasons given. Occasional basophils extruded their granules, and individual granules, retaining their characteristic ultrastructure, were commonly seen in the interstitium. However, intercellular junctions between endothelial cells were closed except during cell emigration and there was no morphologic evidence of an histamine-like effect. The majority of basophils, moreover, did not degranulate but underwent nuclear pyknosis and cytoplasmic degeneration and were phagocytosed by macrophages. Phagocytosed basophil granules retained their ultrastructure. Skin tests performed at late intervals after sensitization had a different time course and morphology. Animals sensitized with protein antigens in complete Freund's adjuvant developed delayed hypersensitivity; however, reactions elicited in such animals at early (but not late) intervals after sensitization contained a prominent basophil component. We interpret such reactions to be a mixture of delayed hypersensitivity and cutaneous basophil hypersensitivity. The function of the basophil in CBH and its relation to the mononuclear cells which accompany it are unknown, and various possibilities are discussed. We conclude that cutaneous basophil hypersensitivity is a distinct immunologic and morphologic entity, occurring early in the course of sensitization with protein antigens incorporated in any of several vehicles. The mechanism of the reaction is presently unknown, and a general hypothesis to explain its pathogenesis has been proposed.

Genetic control of the immune response of guinea pigs to limiting doses of bovine serum albumin: relationship to the poly-L-lysine gene

The response of strain 2 guinea pigs to limiting doses of bovine serum albumin is under dominant genetic control linked with the poly-L-lysine gene. Inbred strains 2 and 13 guinea pigs make similar antibody responses to 10 mug bovine serum albumin, whereas strain 2 but not strain 13 animals produce significant amounts of antibodies in response to 0.1 mug. The relationship between the presence of the poly-L-lysine gene and the ability to respond to limiting doses of bovine serum albumin has also been investigated in random-bred Hartley strain guinea pigs.

Linkage between the poly-L-lysine gene and the locus controlling the major histocompatibility antigens in strain 2 guinea pigs

The data presented demonstrate linkage between the major histocompatibility locus of inbred strain 2 guinea pigs and a "specific immune response gene," the PLL gene, which controls responsiveness to poly-L-lysine and hapten conjugates of this polypeptide in these animals. This finding extends to another species and to a different immune system the linkage observed in mice between the H(2) locus and specific immune response genes at the Ir-1 locus. The general significance of the linkage of specific immune response genes to histocompatibility loci is discussed.