In vitro and in vivo induction of effector T cells mediating DTH responses to a protein and a synthetic polypeptide antigen

Desensitization of the insulin receptor by antireceptor antibodies in vivo is blocked by treatment of mice with beta-adrenergic agonists

In previous studies we reported that immunization of mice with ungulate insulins induced the development of antiinsulin antibodies, which include an idiotype that appeared to recognize the part of the insulin molecule recognized by the hormone receptor. The antiinsulin antibodies of this idiotype were replaced spontaneously by antiidiotypic antibodies. The antiidiotypic antibodies, which persisted for about 14 d, mimicked insulin and functioned as antibodies to the insulin receptor. They induced down regulation, desensitization and refractoriness of the insulin receptor and disturbances in glucose homeostasis in vivo (Shechter, Y., D. Elias, R. Maron, and I.R. Cohen., 1984; Elias, D., R. Maron, I.R. Cohen, and Y. Shechter. 1984, J. Biol. Chem. 259: 6411-6419). We now report that effects of the antiidiotypic antibodies on the insulin receptor effector system can be modified pharmacologically. Administration of the beta-adrenergic agonist isoproterenol during the period of insulin resistance (days 26-40 after primary immunization), largely restored fat cell responsiveness to insulin, and eliminated the appearance of fasting hyperglycemia. This restoration appeared to be caused by inhibition of both insulin receptor desensitization and refractoriness. In contrast, down regulation of insulin receptors was not reversed by isoproterenol treatment in vivo. The effects of treatment with isoproterenol persisted for 2-4 d after termination of treatment. The beta-antagonist, propranolol and more so, the beta 1a-antagonist metoprolol, specifically blocked the effect of isoproterenol at a molar ratio of 3-10:1. Oral administration of the cAMP phosphodiesterase inhibitor, aminophylline, was also effective in inhibiting the development of desensitization in fat cells. These results indicate that treatment with beta 1-adrenergic agonists in vivo, or other agents that elevate cellular cAMP levels, can inhibit the development of the "postbinding" defects induced by insulin-mimicking, antireceptor antibodies. These observations have both basic and clinical implications.

Functional requirements of (Phe, G)-A--L-specific T-cell clones of (H-2b X H-2k)F1 origin

T-cell clones specific for the synthetic polypeptide antigen poly(LPhe, LGlu)-poly(DLAla)--poly(LLys) of (C57BL/6 X C3H/HeJ)F1 origin were tested for their biological activities. One group of clones was restricted in its proliferative response to the H-2b haplotype, the second to the H-2k haplotype, and the third to the F1 unique Ia determinants. All the clones which proliferated in response to antigen secreted interleukin-2 (IL-2) following stimulation. The H-2 restriction of the IL-2 secretion was the same as that of the proliferation. Two of the clones tested, C.6 and C.10, could provide help to B cells in antibody production. However, the genetic restriction profile of the helper activity was less stringent than that for the proliferative response. Thus, C.6, which proliferated in the presence of F1 antigen-presenting cells only, could help B cells and accessory cells of C3H/HeJ. C.10, which was restricted in its proliferative response to the H-2b haplotype, could collaborate with B cells and accessory cells of the H-2k haplotype as well. The antibody response of both clones was restricted to the parental or F1 strains.

T lymphocytes of rheumatoid arthritis patients show augmented reactivity to a fraction of mycobacteria cross-reactive with cartilage

An acetone-precipitable fraction of Mycobacterium tuberculosis cross-reacts with human cartilage. Immune responses to this antigen were assessed in 34 patients with rheumatoid arthritis, 16 patients with degenerative joint disease, and 15 healthy controls. The RA patients differed from the other two groups in having more pronounced T lymphocyte responses to the antigen; their serum antibody levels were not higher. The responses of RA patients varied with duration of disease. In the first year (7 patients) T lymphocyte reactivity was increased in the synovial exudates of affected joints but not in peripheral blood, whereas the 19 with disease of 1-10 years' duration showed high reactivity in peripheral blood; in the 8 with disease for more than 10 years, lymphocyte reactivity did not differ from that in the patients with degenerative joint disease or the healthy controls. The observation that the three groups did not differ in their responses to streptococci and a T-cell mitogen indicates that reactivity of the RA patients to the mycobacterial fraction was specific. These results raise the possibility that bacterial antigens cross-reactive with cartilage proteoglycans may be relevant to the pathogenesis of RA.

Analysis of the biological functions and fine specificity of (T,G)-A--L specific T cell clones

Two T cell lines, TPB1 and TPB2, specific for the synthetic polypeptide antigen (T,G)-A--L, were established from (T,G)-A--L primed lymph node cells of C3H.SW(H-2b) mice. Both lines proliferated in the presence of (T,G)-A--L, helped in antibody production in vitro, and secreted IL2 upon stimulation with antigen. The lines differed in the fine specificity of their responses to antigenic stimulation. The line with the broader specificity TPB2 was cloned by limiting dilution, and its derived clones were analyzed. No efficient manifestation of both proliferative activity and helper function could be detected in a single clone. Most of the clones were highly specific to (T,G)-A--L, although 2 of them cross-reacted with the closely related polypeptide (Phe,G)-A--L. Individual clones could trigger B cells for the production of antibodies of the IgM and IgG classes. All helper clones secreted (T,G)-A--L specific helper factors. No correlation was found between efficient secretion of IL2 by the clones and their other biological functions.

Extracorporeal removal of specific antibodies by hemoperfusion through the immunosorbent agarose-polyacrolein microsphere beads: removal of anti-bovine serum albumin in animals

We describe the production of a unique immunosorbent system, agarose-polyacrolein microsphere beads (APAMB) for removal of a specific antibody, anti BSA, and its efficacy in animal trials. This is a model system for hemoperfusive removal of specific antibodies or antigens directly from whole blood. The agarose beads (1.0 mm mean diameter) contain thousands of microspheres of 0.2 micron mean diameter. The microspheres which contain the ligand are encapsulated within an agarose matrix to confer physical strength, biocompatibility, spacial configuration, and porosity allowing rapid entry of plasma for reaction. Any antigen may be linked covalently to spacers on the polyacrolein microspheres to remove a specific antibody, or vice versa. Thus the APAMB remove specific molecules in contrast to the charcoal or ion exchange resins currently in use. Removal of antibody is efficient and rapid, therefore, short hemoperfusive times may be used. The beads are biocompatible; there are negligible decreases in RBC, WBC and platelets. Electrolytes and other soluble components also are minimally affected. Therapy, at the least palliative, of autoimmune disorders i.e., multiple myeloma, macroglobinemia, autohemolytic anemias, idiopathic thrombocytopenia, myasthenia gravis, rheumatoid arthritis, thyroiditis, glomerulonephritis, etc, is potentially available with this or its further improved versions.

Selective induction of delayed hypersensitivity T-effector and T-suppressor lymphocytes in vitro by haptenized bone marrow-derived macrophages

The role of various subpopulations of antigen-presenting macrophages in the induction of T-lymphocyte subpopulations has been difficult to study in the past. We have used an in vitro system of bone marrow cell culture both to induce T-effector (TDH) and T-suppressor (Ts) cells active in delayed-type hypersensitivity. Bone marrow-derived macrophages (BM-MA) grown in Teflon bag cultures were allowed to attach to culture dishes and were pulse-labeled with 2,4-dinitrobenzene sulfonate (DNBSO3). Spleen cell lymphocytes from nonsensitized BALB/c mice were cocultured with antigen-pulsed or control BM-MA for 3 days. The lymphocytes were harvested, and injected iv into BALB/c mice which were challenged within 1 hr after injection by painting the right ear with 2,4-dinitrofluorobenzene (DNFB, effector test) or sensitized with DNFB on 2 days following iv injection of the cells and challenged 5 days later (suppressor test). Ear swelling was measured 24 hr later to assess the effector or suppressor function of the in vitro educated lymphocytes. BM-MA grown for 5 days (BM-MA 5) in L-cell conditioned medium induced only TDH cells (Thy 1+, Lyt 1+2-) whereas BM-MA grown for 10 days in conditioned medium induced only Ts cells (Thy 1+, Lyt 1-2+). In both cases, induced TDH and Ts cells were antigen specific. Functionally, induced Ts cells suppressed the afferent limb of the delayed response. When DNP-BM-MA 5 and DNP-BM-MA 10 were used to induce TDH or Ts cells in vivo by subcutaneous or intravenous injection respectively, only BM-MA 5 were able to sensitize recipient mice. Both 5- and 10-day macrophage populations induced Ts cells in vivo. Functionally, these Ts cells appeared to act on the efferent limb of the delayed reaction. We conclude that different populations of antigen-presenting macrophages can preferentially induce TDH or Ts cells, perhaps depending on antigen presentation in association with class II antigens or on the functional state of the antigen-presenting cell.

Cell-mediated immunity in rats injected with an antimalaria T-cell line

The aim was to develop a pure T-cell line which would enable the study of some aspects of the cellular immunity of malaria-injected rodents. For this purpose a long-term proliferative antimalaria T-cell line (AMTL) was established. The line was developed from splenocytes of rats recovered from a Plasmodium berghei infection. After adoptive transfer of the AMTL, some protection was demonstrated either by a lower mortality rate after challenge with the parasite or by decreased parasitemia in the T-cell injected versus control groups. Specific delayed-type hypersensitivity (DTH) was elicited by the AMTL: normal rats injected with the AMTL showed a DTH reaction to malaria antigens similar to the response observed in convalescent animals. Specificity was demonstrated by a marked response of the AMTL injected rats compared to rats injected with a control line (anti-purified protein derivative of tuberculin).

Agarose-polyaldehyde microsphere beads: synthesis and biomedical applications. Cell labeling, cell separation, affinity chromatography, and hemoperfusion

Polyaldehyde microspheres, polyglutaraldehyde (PGL), and polyacrolein (PA) were synthesized by polymerizing glutaraldehyde and acrolein in the presence of an appropriate surfactant. The microspheres with average diameter of 0.2 micron were used for the specific labeling of human red blood cells (RBC) and mouse lymphocytes. The "naked" microspheres were encapsulated with agarose and formed agarose-polyaldehyde microsphere beads in sizes ranging from 50 microns up to 1 cm. The encapsulated beads, with diameters ranging from 50 to 150 microns were used as insoluble adsorbents for affinity purification of antibodies. Beads with diameters varied from 150 to 250 microns were used for cell fractionation purposes (mouse B splenocytes from T splenocytes). Uniform beads of 1 mm diameter were designed for hemoperfusion purposes. As a model, the removal in vitro of anti-BSA from immunized goat whole blood was studied.

Fine specificity of antibodies to the synthetic polypeptide poly(L-tyrosine, L-glutamic acid)-poly(DL-alanine)--poly(L-lysine) and its ordered analogs as followed by solid-phase radioimmunoassay

The fine specificity of antibodies against (T,G)-A--L and its ordered analogs (T-T-G-G)-A--L and (T-G-T-G)-A--L was studied. Fifty percent of the antibodies against (T,G)-A--L are directed toward the T-T-G-G determinants and 19% against T-G-T-G-like determinants. The rest of the antibody response to (T,G)-A--L is directed against determinants which exist in (T,G)-A--L but are not cross-reactive with either T-T-G-G- or T-G-T-G-like determinants. Although (T-T-G-G)-A--L and (T-G-T-G)-A--L differ only in the sequence of tyrosine and glutamic acid in their side chains, no crossreactivity was observed between antibodies toward the two ordered polypeptide antigens.

Cellular sensitivity to collagen in thromboangiitis obliterans

We studied 39 patients with thromboangiitis obliterans to determine their cellular and humoral immune responses to native human collagen Type I and Type III, which are constituents of blood vessels. Cell-mediated sensitivity to these collagens was measured by an antigen-sensitive thymidine-incorporation assay. The mean stimulation index--the ratio of thymidine incorporation in the presence of antigen to that in its absence--with both Type I and Type III collagens used as antigens was significantly higher in patients with thromboangiitis obliterans than in patients with arteriosclerosis obliterans or in healthy male controls. Lymphocytes from 77 per cent of the patients with thromboangiitis obliterans exhibited cellular sensitivity to human Type I or Type III collagens (or both). Furthermore, in 17 of 39 serum samples from the patients with thromboangiitis obliterans a low but significant level of anticollagen antibody activity was detected, whereas there was no antibody activity in serum samples from controls. These results suggest that there is a distinct etiologic factor in this disease and also raise the possibility of differentiating between thromboangiitis obliterans and arteriosclerosis obliterans by immunologic means.

Mice immunized to insulin develop antibody to the insulin receptor

We immunized mice with insulin and found that those strains that develop insulin antibodies subsequently produce insulin-like activity in amount equivalent to 300-400 ng insulin per ml serum. The activity was due exclusively to IgG2 antibodies. Bioactivity could be blocked efficiently by insulin antibodies from guinea pigs and from mice. The active IgG2 also displaced labeled insulin from fat cells. Preliminary in vivo studies have indicated that the appearance of insulin-like antibodies in the mouse resulted in abnormal glucose homeostasis and "down regulation" of insulin receptors. These results indicate that immunization to insulin can initiate an idiotype-anti-idiotype network resulting in antibodies to the hormone receptor.

Molecular events in the processing of avidin by antigen-presenting cells (APC). III. Activation of T-lymphocyte lines and H-2 restriction are mediated by processed avidin associated with I-region gene products

We investigated the interaction between processed avidin (PA) and avidin-specific lines of T lymphocytes free of resident antigen-presenting cells (APC). We found that PA was able to replace the requirement for APC in the T-lymphocyte proliferative assay, only if the PA was associated with an Ia-positive moiety (IPM) supplied by the APC. In addition to supplying a necessary signal for a proliferative response to PA, IPM imposed H-2 restriction on the PA molecule. The association between PA and IPM was reversible and the two moieties could be physically separated and recombined. The results support a conclusion that major histocompatibility restriction of the interaction between T lymphocytes and APC is due to the association between processed antigen and an APC element containing I-region products.

Molecular events in the processing of avidin by antigen-presenting cells (APC). I. The immune response of T lymphocytes to avidin is regulated by H-2-linked Ir genes

The immune response of T lymphocytes to avidin was measured by proliferative assays, antibody production and delayed-type hypersensitivity. Mice of H-2k haplotypes were found to be low responders, whereas mice of other haplotypes, and particularly of H-2s, were high responders. Ir genes controlling this response were mapped to the I subregion of H-2. Helper T cells were found to be responsible for the Ir phenotype of antibody production. These results indicate the feasibility of using the avidin-biotin complex as a tool for studying molecular mechanisms by which antigens under Ir gene control are processed and presented to T lymphocytes.

Cellular analysis of specificity of antibodies and of delayed type hypersensitivity responses toward some structurally related synthetic antigens: boosting is determined by specificity of T cells

The crossreactivity between the random synthetic polypeptide antigen poly(Tyr,Glu)-poly(DLAla)--poly(Lys) [(T,G)-A--L] and its ordered-sequence analogs (Tyr-Tyr-Glu-Glu)-poly(DLAla)--poly(Lys) [(T-T-G-G)-A--L] and (Tyr-Glu-Tyr-Glu)-poly(DLAla)--poly(Lys) [(T-G-T-G)-A--L] at the level of humoral and cellular responses was studied. For delayed type hypersensitivity responses, (T,G)-A--L-activated T cells could be challenged with the homologous antigen as well as with the ordered analogs. T cells activated by (T-T-G-G)-A--L could be challenged with either the homologous antigen or with (T,G)-A--L but not with (T-G-T-G)-A--L. Similarly, no cross stimulation was observed between (T-G-T-G)-A--L-activated cells and (T-T-G-G)-A--L, whereas (T,G)-A--L could challenge the latter cells to mediate significant responses. Similar but not identical cross reactions were observed when primed spleen cells or lymph nodes were transferred to irradiated recipients that were boosted for the production of antibodies. In contrast to observations at the level of cellular responses, (T-G-T-G)-A--L-primed spleen or lymph node cells could not be boosted with (T,G)-A--L for the production of detectable amounts of antibodies, although boosting with the homologous antigen resulted in significant levels of (T-G-T-G)-A--L-specific antibodies. Transfer experiments in which mixtures of T and B cells, each primed to a different ordered polypeptide antigen, were injected into irradiated recipients showed that successful cooperation occurs provided that the boost is given with the T-cell-specific antigen. The antibodies produced were specific to the antigen used for B-cell priming. The T-cell-B-cell collaboration probably occurs through specific determinants that are shared between the two antigens in which the ordered peptides are attached to the same multichain polymer and that are recognized by both the T and the B cells.

Autoantibodies to insulin receptor spontaneously develop as anti-idiotypes in mice immunized with insulin

Mice immunized with insulin developed antibodies to both insulin and the insulin receptor. The antibodies to insulin receptor displaced labeled insulin from insulin receptors and mimicked the actions of insulin in stimulating the oxidation of glucose and its incorporation into lipids, and in inhibiting lipolysis. The antibodies to insulin receptor could be blocked by or bound to the antibodies to insulin, and therefore were identified as anti-idiotypes. Thus, immunization against a hormone may activate spontaneously an idiotype-anti-idiotype network resulting in antibodies to the hormone receptor.

A new immunoadsorbent for hemoperfusion: agarose-polyacrolein microspheres beads. I. In vitro studies

The development and properties of a novel adsorbent system consisting of polyacrolein microspheres encapsulated in agarose is described. In the model system, the microspheres contain covalently bound bovine serum albumin. In practice any protein or ligands with primary amino groups may be covalently bound. Circulating antibovine serum albumin antibodies were adsorbed from whole blood or serum of rabbits or goats onto the microspheres. The capacity of this batch is 10 mg antibody adsorbed/gm wet weight beads. When the column is operated at less than capacity, 50%, 70%, 90% and 95% of the anti BSA is adsorbed in 30, 60, 120 and 180 min, respectively. Thus, relatively short periods of hemoperfusion may be used. The beads are biocompatible. There are negligible decreases of RBC; up to a 10% decrease of WBC and up to a 20% decrease of platelets in 3 hrs. The beads are stable; neither breakdown nor leakage was observed over a period of 3 months. High flow rates were readily obtained. The mean diameter of the microspheres is 0.2 mu; the mean diameter of the agarose polyacrolein microspheres beads (APAMB) is 1.0 mm. We can produce monodisperse beads of any given diameter ranging from 200 mu to 1 cm.

Antibodies to the F1-ATPase of Rhodospirillum rubrum and its purified native beta-subunit: inhibition of ATP-linked activities in R. rubrum and in lettuce

1. Antibodies prepared against the Rhodospirillum rubrum F1-ATPase (RrF1) and its purified, native-beta-subunit, exhibited cross-reactivity with the following soluble preparations of R. rubrum ATPase: RrF0 . F1, RrF1 and the beta-subunit. Anti-RrF1, but not anti-beta antibodies, also formed precipitin lines with soluble beta-less Rrf1, indicating that antigenic determinants of both the beta-subunit and the other four RrF1-subunits are expressed in the whole RrF1 molecule. Both antibodies agglutinated the R. rubrum chromatophores, suggesting that the beta-subunit is located on the external part of RrF1. 2. Both antibodies inhibited ATP synthesis and hydrolysis activities of R. rubrum chromatophores, as well as all the soluble ATPase reactions. Similar concentrations of each antibody were required for 50% inhibition of all these reactions, but anti-RrF1 was always somewhat more effective than anti-beta. These data indicate that the beta-subunit is involved in the catalytic site of the RrF1-enzyme. 3. The antibodies prepared against R. rubrum F1-ATPase and its beta-subunit could bind the soluble chloroplast F1-ATPase (CF1) and inhibited ATP-linked reactions carried out by chloroplasts and by soluble CF1. In these reactions, unlike in the R. rubrum ones, anti-beta was a more potent inhibitor than the anti-RrF1 antibody. The cross-reaction obtained between the antibodies raised against R. rubrum F1 and its beta-subunit and the chloroplast CF1 indicates the presence of similar antigenic determinants in the photosynthetic prokaryotic and eukaryotic F1-ATPases, which have been conserved during evolution.

Immune response potential to poly(Tyr,Glu)-poly(DLAla)--poly(Lys) of human T cells of different donors

Human peripheral blood T cells of normal donors were activated in vitro with autologous adherent cells pulsed with poly(LTyr,LGlu)-poly(DLAla)--poly(LLys) [abbreviated (T,G)-A--L]. The "educated" T cells were tested: (i) for their ability to produce a (T,G)-A--L-specific T cell-replacing factor in the cooperation with B cells for antibody responses in vivo or in vitro and (ii) for their ability to proliferate in the presence of a second stimulus of (T,G)-A--L. Results of screening of 66 donors demonstrated that educated T cells of about 50% of the donors produced an active (T,G)-A--L-specific factor, whereas activated cells of only half of the factor producers were capable of proliferating in the presence of the antigen. Thus, as reported for all other species studied, human individuals differ in their response potential to (T,G)-A--L.

Effect of helper T cells on the primary in vitro production of delayed-type hypersensitivity to influenza virus

Injection of mice with infectious or noninfectious preparations of influenza virus induces the formation of T cells which, when added to primary tissue cultures of normal spleen cells exposed to influenza virus, enhance the generation of effector T cells which mediate delayed-type hypersensitivity (DTH) reaction. The enhancing cells possess Thy-1 and Ly-1 surface antigens are radioresistant and antigen-specific. If infectious virus was used to stimulate the DTH response in vitro, help was delivered whether homologous or heterologous A strain influenza virus was used to generate the helper T cells (Th) in vivo. In contrast, only Th cells generated using homologous virus were effective if noninfectious virus was used to stimulate the DTH response in vitro. Peak helper activity occurred 2 d after virus injection and the Th cells were only effective if added to the primary cultures within 24 h after addition of the stimulating antigen. The Th cells enhanced the generation of both classes of DTH effector cells, i.e., those that are Ly-1 positive and IA-subregion restricted and those that are Ly-2,3 positive and K,D-region restricted. The activity of the Th cells was found to be IA-subregion restricted and this was shown to operate at the level of the stimulator cells so that the delivery of help to the responder cells was not H-2 restricted. The possibility that the Th cells might be a precursor to the Ly-1 positive IA subregion-restricted DTH effector cells is discussed.

Liposomes as immunological adjuvants in eliciting antibodies specific to the synthetic polypeptide poly(LTyr, LGlu)-poly(DLAla)--(LLys) with high frequency of site-associated idiotypic determinants

The antibody response to the synthetic polypeptide, poly(LTyr, LGlu)-poly(DLAla)--poly(LLys), [(T,G)-A--L], injected entrapped in liposomes which served as adjuvant has been analyzed. The liposomes used were composed of phosphatidylcholine, cholesterol, dicetylphosphate and DL alpha-tocopherol (molar ratios as 4:3:0.1:0.5) and therefore, were negatively charged. Since the (T,G)-A--L is also negatively charged, no free complexes were formed. The (T,G)-A--L was found to be entrapped inside the enclosed volume of the liposomes, and no (T,G)-A--L antigenic determinants could be detected on the liposomal membranes. Injection of high-responder C3H.SW (H-2b) mice with (T,G)-A--L-bearing liposomes demonstrated that the i.p. and the i.v. routes of immunization were efficient in eliciting (T, G)-A--L specific antibodies, whereas the i.d. injection led to poor antibody responses. The latter route of immunization is the most effective when (T,G)-A--L is injected in complete Freund's adjuvant (CFA). When low doses (0.1 and 1 microgram) of (T, G)-A--L were used for immunization, the liposomes were better adjuvants than CFA. The effectiveness of the liposomes as immunological adjuvants was also shown in their ability to induce high-potential, primed memory cells. The pattern of low (H-2k,a) and high (H-2b) responsiveness to (T,G)-A--L was retained following immunization with (T,G)-A--L entrapped in liposomes, as tested in two pairs of congenic strains. (T,G)-A--L-specific antibodies induced by injection with 1 microgram antigen entrapped in liposomes bear the (T,G)-A--L site-related idiotypic markers of C3H.SW (Igh-1a) mice in a significantly higher frequency than the homologous idiotypes, namely the antibodies elicited in this strain against (T,G)-A--L in CFA. Thus, liposomes may serve as adjuvants for the production of relatively restricted (T,G)-A--L-specific antibodies of high quality.

Enhancing effect of murine anti-idiotypic serum on the proliferative response specific for poly(LTyr, LGlu)-poly(DLAla)--poly(LLys)[(T,G)-A--L]

Murine anti-idiotypic serum against C3 H.SW anti-poly(LTyr, LGlu)-poly(DLAla)--poly(LLys)[(T,G)-A--L] antibodies was elicited in C57BL/6 mice. The effect of the anti-idiotypes on the proliferation of primed lymph node cells was investigated. The anti-idiotypic serum stimulated the proliferative response of the (T,G)-A--L-specific lymph node cells as well as of nylon wool-enriched T cells. In the presence of suboptimal doses of (T,G)-A--L, the addition of the anti-idiotypes enhanced the proliferation to the levels obtained with the optimal dose of (T,G)-A--L itself. These results suggest the existence of shared idiotypic determinants between antibodies and the (T,G)-A--L-specific proliferative T cells.

Antiviral response elicited by a completely synthetic antigen with built-in adjuvanticity

In a previous study we demonstrated that antiviral response against the coliphage MS-2 can be elicited by immunization with a synthetic antigen consisting of a conjugate (P2-A -- L) of a synthetic fragment (P2) of the virus coat protein attached to a synthetic polymeric carrier. The antiviral response was induced when the antigen was administered in complete Freund's adjuvant or when it was administered in incomplete adjuvant, provided that a peptidoglycan was covalently attached to it. In the present study we demonstrate the adjuvant effect of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) in this system. Immunization with a mixture of MDP and P2-A -- L brought about only slight enhancement in the titer of neutralizing antibodies, as compared to the immunization with P2-A -- L in saline. The best results were achieved when the MDP was chemically conjugated to P2-A -- L. This completely synthetic material, when administered in aqueous solution, yielded highly inactivating antiserum with a titer similar to that obtained with complete Freund's adjuvant in the absence of MDP. MDP-P2-A -- L elicited also a humoral immune response to MDP, but with much lower titer than that induced by complete Freund's adjuvant containing P2-A -- L only. It was also observed that the capacity of MDP-P2-A -- L to increase resistance against infection was more than a 100-fold greater than that of unconjugated MDP.

Elicitation of delayed-type hypersensitivity responses to poly(L-Tyr,LGlu)-poly(DLAla)--poly(LLys) by anti-idiotypic antibodies

The in vivo effect of murine anti-idiotypic serum against C3H.SW anti-poly(LTyr,LGlu)-poly(DLAla)-(LLys) [(T,G)-A--L] antibodies on delayed type hypersensitivity responses to (T,G)-A--L was studied. Anti-idiotypic serum could challenge DTH responses in C3H.SW mice transferred with antigen-sensitized T cells. The elicitation activity was shown to be antigen and strain specific. With H-2-compatible (but allotype different) strain combinations of (T,G)-A--L-educated T cells and recipients, we were able to show that the biological effect of the anti-idiotypic serum is expressed on the first antigen-sensitized idiotype-positive radioresistant T cell, but not on the proliferating normal cells of recipient origin that participate in the efferent phase of delayed-type hypersensitivity responses to (T,G)-A--L.

H-2K mutation controls immune response phenotype of autoimmune thyroiditis. Critical expression of mutant gene product in both thymus and thyroid glands

Autoimmune thyroiditis (EAT) can be induced by immunizing mice against mouse thyroglobulin. A gene critical to the phenotypical expression of EAT was mapped to the H-2K locus by studying B6 mice and its mutant strain B6.H-2ba. To identify organs in which expression of the gene was decisive for the EAT phenotype, we transplanted thyroid or irradiated thymus glands into various strains of normal mice or thymusless nude mice. We found that the pathophysiology of EAT was controlled by the expression of specific H-2 genes in both the target thyroid gland and the thymus gland.

Efficient genetically controlled formation of antibody to a synthetic antigen [poly(LTyr, LGlu)-poly(DLAla)- -poly(LLys)] covalently bound to a synthetic adjuvant (N-acetylmuramyl-L-alanyl-D-isoglutamine)

The synthetic polypeptide antigen poly(LTyr, LGlu)-poly(DLAl)- -poly(LLys)[T,G)-A- -L] was covalently linked to N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP), which is the minimal adjuvant-active structure that can substitute for Mycobacteria in complete Freund's adjuvant. When injected in aqueous solution into mice, the completely synthetic conjugate elicited significant antibody responses specific to (T,G)-A- -L, whereas (T,G,)-A- -L alone administered under the same conditions did not lead to antibody production. The conjugate was much more efficient in eliciting (T,G)-A- -L responses than was a mixture of DMP and (T,G)-A- -L. One hundred micrograms of MDP mixed with 10 micrograms of (T,G)-A- -L resulted in production of (T,g)-A- -L-specific antibodies. However, the titers obtained were much lower than those observed with 10 micrograms of the conjugate, MDP-(T,G)-A- -L, which contained less than 1 microgram of MDP. MDP was enhanced when the mixture was administered in incomplete Freund's adjuvant, the adjuvant did not significantly affect the (T,G)-A- -L-specific antibody responses in mice immunized with MDP-(T,G)-A- -L. The isoelectric focusing pattern of antibodies obtained with MDP-(T,G)-A- -L was similar to that obtained after immunization with (T,G)-A- -L in complete Freund's adjuvant. The pattern of high-responder and low-responder mice to (T,G)-A- -L, the immune response to which is genetically controlled, was retained when MDP-(T,G)-A- -L was used as the immunogen. Conjugation of (T,G)-A- -L was creased the immunogenicity of MDP and affected its biological properties. It is thus possible to obtain efficient immune responses to synthetic polypeptide antigens that produce poor reactions when injected in aqueous solution by conjugating them to small molecular weight synthetic adjuvants.

Genetic regulation of delayed-type hypersensitivity responses to poly(LTyr,LGlu)-poly(DLAla)--poly(LLys). II. Evidence for a T-T-cell collaboration in delayed-type hypersensitivity responses and for a T-cell defect at the efferent phase in nonresponder H-2k mice

The intercellular interactions and the site of the genetic defect in delayed-type hypersensitivity (DTH) response to poly(LTyr,LGlu)-poly(DLAla)--poly(LLys) [(T,G)-A--L] has been studied in a system where the T-cell education phase was separated from the efferent phase. In the cellular response, T-T-cell collaboration is required, because T cell-depleted mice were unable to manifest DTH responses after they were transferred with educated and irradiated T cells. Reconstitution of adult thymectomized mice that were irradiated and supplemented with bone marrow cells after treatment with anti-Thy-1.2 serum and complement, with T cells but not with accessory cells gave rise to significant responses. Educated, radioresistant cells required the presence of normal radiosensitive T cells for successful DTH responses to (T,G)-A--L. The genetic defect of nonresponder H-2k and H-2a mice has been located in the above-mentioned, second T-cell population that participates in the efferent phase of this immune reaction. Further characterization revealed that the educated cells are of the Lyt1+ phenotype and that the second normal T cells are expressing the Lyt 1+,2+,3+ phenotype. Thus, the genetic defect of H-2k and H-2a mice in the DTH response to (T,G)-A--L is expressed on the non-antigen-stimulated Lyt 1+,2+,3+ T cells.

Genetic regulation of delayed-type hypersensitivity responses to poly(LTyr,LGu)-poly(DLAla)--poly(LLys). I. Expression of the genetic defect at two phases of the immune process

Delayed-type hypersensitivity (DTH) responses served in this study as an experimental model for the analysis of genetic regulations of T-cell responses. Educated irradiated cells from H-2b mice mediated responses in syngeneic recipients, whereas mice of the a, d, f, k, and s haplotypes were nonresponders to poly(LTyr,LGlu)-poly(DLAla)--poly(LLys)[(T,G)-A--L]. These results suggest that cell-mediated immune responsiveness to (T,G)-A--L is linked to the H-2 complex, as was shown for humoral responses. Educated irradiated T cells of F1 hybrids between high and low responders mediated DTH responses, which indicates that the gene(s) controlling the DTH responses is dominant. To analyze the genetic defect in DTH responses to (T,G)-A--L, we separated the T-cell activation phase from the effector phase that was determined in recipient mice. Two types of nonresponders were observed: (a) When lymphocytes of the a or k haplotypes were educated in a syngeneic environment and then transferred into hybrids between the parental (nonresponder x responder) F1 recipients, DTH responses could have been manifested. (b) On the other hand, no DTH responses could be mediated by transferring educated cells of the H-2s or H-2f origin into the appropriate F1 recipients. In addition, irradiated F1 cells that had been activated to (T,G)-A--L could not mediate DTH responses in both types of nonresponder recipients. These results suggest that T cells of H-2k or H-2a mice can be activated to generate DTH responses to (T,G)-A--L and that the defect in these mouse strains is expressed in another cell population needed for the manifestation of the DTH reaction in the recipient mice. In contrast, T cells of H-2s and H-2f origin cannot be activated to (T,G)-A--L and, thus, fail to manifest DTH responses.