HAPTEN-SPECIFIC IgE ANTIBODY RESPONSES IN MICE : II. COOPERATIVE INTERACTIONS BETWEEN ADOPTIVELY TRANSFERRED T AND B LYMPHOCYTES IN THE DEVELOPMENT OF IgE RESPONSE

The present studies have established conditions for the demonstration of cooperative interactions between specific T and B lymphocyte populations in the development of IgE antibody responses in vivo in mice. This has been accomplished by utilizing a system which permits the successful adoptive transfer to irradiated recipients of DNP-specific secondary IgE responses with spleen cells from suitably primed syngeneic donor mice. Thus, adoptively transferred DNP-KLH or DNP-ASC-primed spleen cells produced high levels of anti-DNP antibodies of both IgE and IgG antibody classes in response to challenge with the appropriate homologous priming conjugate but failed to develop more than meager responses to the reciprocal heterologous conjugate. However, when spleen cells from donors primed to the second carrier were concomitantly transferred with hapten-primed lymphocytes, secondary IgE ant-DNP responses were consistently obtained upon challenge with the heterologous conjugate. Moreover, we have been able to elicit augmented primary IgE anti-DNP antibody responses to either DNP-ASC or DNP-KLH after adoptive transfer of spleen cells from donors primed only to the carrier, ASC or KLH, respectively. This adoptive transfer system has enabled us to provide direct proof for the participation of θ-bearing T lymphocytes in antibody responses of the IgE class. Thus, the capacity of ASC-primed spleen cells to effectively cooperate with the DNP-KLH-primed lymphocytes in the adoptive secondary response to DNP-ASC could be abolished by in vitro treatment of such cells with anti-θ serum plus complement. This was true not only for the anti-DNP response of the IgG antibody class, but for the IgE antibody class as well. These studies have, furthermore, demonstrated the capacity to stimulate secondary anti-DNP antibody production in vivo by the concomitant administration of the DNP and relevant carrier determinants on separate molecules. This was more readily seen in the IgE than in the IgG antibody class. Thus, DNP-ASC-primed cells developed significant IgE, but more variable IgG, anti-DNP responses upon challenge with DNP-KLH plus unconjugated ASC. Antibody responses of both classes elicited in this manner were appreciably improved by the transfer of additional carrier (ASC)-primed cells. These and other results presented herein suggest that IgE B lymphocyte precursors may be inherently more sensitive than IgG B cells to at least certain of the functions of T lymphocytes concerned with regulatory mechanisms involved in antibody production

IMMUNOLOGICAL TOLERANCE IN BONE MARROW-DERIVED LYMPHOCYTES : I. EVIDENCE FOR AN INTRACELLULAR MECHANISM OF INACTIVATION OF HAPTEN-SPECIFIC PRECURSORS OF ANTIBODY-FORMING CELLS

Administration of the 2,4-dinitrophenyl (DNP) derivative of the copolymer of D-glutamic acid and D-lysine (D-GL) to inbred mice induces a state of DNP-specific tolerance in such animals irrespective of their immune status at the time of treatment. Taking advantage of the relative ease with which DNP-D-GL can induce tolerance in an animal previously primed with an immunogenic DNP-carrier conjugate, we have established conditions for tolerance induction in an adoptive cell transfer system. Thus, the adoptive secondary anti-DNP antibody response of DNP-keyhole limpet hemocyanin (KLH)-primed spleen cells was completely, or almost completely, abolished by exposure of such cells to DMP-D-GL either in vivo or in vitro. Tolerance induction in vivo occurred irrespective of whether the DNP-primed cells were exposed to DNP-D-GL in the donor animal before adoptive transfer or in recipient mice after transfer. In the latter situation, it was possible to show that tolerance induction in this model occurs very rapidly (1 hr) and with relatively low doses of tolerogen (50 µg). Incubation of DNP-KLH-primed cells with DNP-D-GL in vitro under varying culture conditions also resulted in depression of the adoptive secondary response of such cells, although the kinetics and degree of tolerance induction in this way were slightly different from that obtained by in vivo tolerization. Utilizing the adoptive transfer tolerance system, it was possible to approach certain questions concerning the mechanism of tolerance induction and fate of tolerant bone marrow-derived (B) lymphocytes in the DNP-D-GL model. The possibility that suppression of anti-DNP antibody from the DNP-D-GL reflects blocking of surface receptor molecules on B lymphocytes has been ruled out by several experimental observations. The most conclusive evidence on this point derives from the failure of enzymatic treatment with trypsin to reverse the tolerant state induced by in vitro exposure of primed cells to DNP-D-GL, whereas trypsinization completely restored the immunocompetence of DNP-KLH-primed cells rendered unresponsive by exposure to DNP-ovalbumin in vitro. The present studies also demonstrate that the tolerant state induced by DNP-D-GL represents a predominantly irreversible inactivation of specific B lymphocytes. This conclusion is derived from experiments in which it was found that tolerance was maintained through as many as two serial adoptive transfers performed over a period of time of at least 24 days from the single exposure of such cells to the tolerogen. Moreover, the possibility that maintenance of tolerance through such serial transfers was due to inadvertent transfer of tolerogenic doses of DNP-D-GL was definitively ruled out. It appears, therefore, that DNP-specific tolerance induced by DNP-D-GL is an example of irreversible inhibition of cell reactivity to antigen reflecting yet-to-be-determined events at the intra- and subcellular levels

CELL INTERACTIONS BETWEEN HISTOINCOMPATIBLE T AND B LYMPHOCYTES : I. ALLOGENEIC EFFECT BY IRRADIATED HOST T CELLS ON ADOPTIVELY TRANSFERRED HISTOINCOMPATIBLE B LYMPHOCYTES

The adoptive transfer of 2,4-dinitrophenyl(DNP)-keyhole limpet hemocyanin(KLH)-primed lymphocytes into a heavily irradiated allogeneic recipient permits the development of a secondary anti-DNP antibody response to DNP-bovine gamma globulin(BGG) whether or not the irradiated allogeneic host possesses BGG-specific helper T cells. This "allogeneic effect" has been demonstrated to result from the capacity of residual, apparently radioresistant, T cells in the irradiated host to exert an active effect on the transferred histoincompatible B lymphocytes. This conclusion derives from two corroborative experiments. In the first, an allogeneic effect was shown to occur on DNP-primed F1 spleen cells that had been adoptively transferred to irradiated parental recipients; the second experiment demonstrated the development of an allogeneic effect on anti-θ-treated, DNP-specific donor cells transferred to irradiated allogeneic hosts. These results emphasize the extreme caution required in designing and interpreting experiments that may involve adoptive cell transfers into histoincompatible hosts, and illustrate why such models are unsuitable for investigation of the question of physiologic cooperative interactions between T and B lymphocytes. Suitable approaches are described in the accompanying paper

The Role of Apelin on the Alleviative Effect of Angiotensin Receptor Blocker in Unilateral Ureteral Obstruction-Induced Renal Fibrosis

Background: Apelin is a selective endogenous ligand of the APJ receptor, which genetically has closest identity to the angiotensin II type 1 receptor (AT-1). The effects of the apelin/APJ system on renal fibrosis still remain unclear. Methods: We examined the effects of the apelin/APJ system on renal fibrosis during AT-1 blockade in a mouse unilateral ureteral obstruction (UUO) model. Results: We obtained the following results: (1) At UUO day 7, mRNA expressions of apelin/APJ and phosphorylations of Akt/endothelial nitric oxide synthase (eNOS) in the UUO kidney were increased compared to those in the nonobstructed kidney. (2) AT-1 blockade by the treatment with losartan resulted in a further increase of apelin mRNA as well as phosphorylations of Akt/eNOS proteins, and this was accompanied by alleviated renal interstitial fibrosis, decreased myofibroblast accumulation, and a decreased number of interstitial macrophages. (3) Blockade of the APJ receptor by the treatment with F13A during losartan administration completely abrogated the effects of losartan in the activation of the Akt/eNOS pathway and the amelioration of renal fibrosis. (4) Inhibition of NOS by the treatment with L-NAME also resulted in a further increase in renal fibrosis compared to the control group. Conclusion: These results suggest that increased nitric oxide production through the apelin/APJ/Akt/eNOS pathway may, at least in part, contribute to the alleviative effect of losartan in UUO-induced renal fibrosis

CELL INTERACTIONS BETWEEN HISTOINCOMPATIBLE T AND B LYMPHOCYTES : IV. INVOLVEMENT OF THE IMMUNE RESPONSE (Ir) GENE IN THE CONTROL OF LYMPHOCYTE INTERACTIONS IN RESPONSES CONTROLLED BY THE GENE

In the present study we have asked the question of whether F1 carrier-primed T cells can serve as helper cells for either or both parental B cells when (a) the carrier molecule employed is under genetic control such that one parental strain is a responder and the other is a nonresponder, and (b) the determinant specificity of the parental B cells being assessed is not under genetic control and bears no relationship to the specificity of the carrier molecule. Utilizing the system of immune response gene control of responses to the terpolymer L-glutamic acid-L-lysine-L-tyrosine (GLT) to which A strain mice (H-2a) are nonresponders, whereas BALB/c (H-2d) and (BALB/c x A)F1 hybrids (CAF1) are responders, these studies demonstrate that GLT-primed T cells of CAF1 donors can provide for responder BALB/c, but not for nonresponder A/J, the required stimulus for the anti-DNP responses of DNP-specific B cells of these respective parental strains to the DNP conjugate of GLT. The implications of these findings for Ir gene function in physiologic T-B cell interactions are discussed in detail

Noninvasive monitoring of deterioration in skeletal muscle function with forearm cast immobilization and the prevention of deterioration

BACKGROUND: In this research inactivity was simulated by immobilizing the forearm region in a plaster cast. Changes in skeletal muscle oxidative function were measured using near-infrared spectroscopy (NIRS), and the preventative effect of the training protocol on deterioration of skeletal muscle and the clinical utility of NIRS were examined. METHODS: Fourteen healthy adult men underwent immobilization of the forearm of the non-dominant arm by plaster cast for 21 days. Eight healthy adult subjects were designated as the immobilization group (IMM) and six were designated as the immobilization + training group (IMM+TRN). Grip strength, forearm circumference and dynamic handgrip exercise endurance were measured before and after the 21-day immobilization period. Using NIRS, changes in oxidative function of skeletal muscles were also evaluated. Muscle oxygen consumption recovery was recorded after the completion of 60 seconds of 40% maximum voluntary contraction (MVC) dynamic handgrip exercise 1 repetition per 4 seconds and the recovery time constant (TcVO(2)mus) was calculated. RESULTS: TcVO(2)mus for the IMM was 59.7 ± 5.5 seconds (average ± standard error) before immobilization and lengthened significantly to 70.4 ± 5.4 seconds after immobilization (p < 0.05). For the IMM+TRN, TcVO(2)mus was 78.3 ± 6.2 seconds before immobilization and training and shortened significantly to 63.1 ± 5.6 seconds after immobilization and training (p < 0.05). CONCLUSIONS: The training program used in this experiment was effective in preventing declines in muscle oxidative function and endurance due to immobilization. The experimental results suggest that non-invasive monitoring of skeletal muscle function by NIRS would be possible in a clinical setting

Induction of Immunological Tolerance in Bone Marrow-Derived Lymphocytes of the IgE Antibody Class

Administration of the 2,4-dinitrophenyl (Dnp) determinant conjugated to the “nonimmunogenic” copolymer of D-glutamic acid and D-lysine (D-GL) induces Dnp-specific immunological tolerance which is essentially restricted to bone marrow-derived (B) lymphocytes. Previous studies have demonstrated tolerance induction by Dnp-D-GL in predominantly B lymphocytes of the IgG class. The present studies establish and analyze conditions for tolerance induction in Dnp-specific B lymphocytes of the IgE antibody class by taking advantage of: (i) the relatively easy capacity to induce tolerance with Dnp-D-GL in an animal or cell population previously primed to the Dnp determinant; (ii) previously established parameters for the successful adoptive transfer of Dnp-specific IgE antibody responses; and (iii) the capacity to induce, and maintain a state of Dnp-specific tolerance with Dnp-D-GL in adoptive transfer responses. Using these approaches, we have successfully rendered Dnp-specific B cells of the IgE class profoundly and apparently irreversibly tolerant after exposure of such cells to Dnp-D-GL. These observations represent a starting point of wide potential for solving many therapeutic problems concerned with clinical allergies