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The antigenic components of adrenal extract were fractionated by chromatography on DEAE-cellulose. Using a stepwise elution procedure, it was found that a component of major interest, termed Pk3b, was eluted by a buffer of pH 6.70 and 0.09 M in phosphate-chloride. This antigenic preparation reacted with several rabbit antisera that had been prepared by isoimmunization with rabbit adrenal homogenate, in contrast to several other fractions, which reacted with only one (or two) of the antisera. Pk3b also showed a high degree of homogeneity, as shown by immunodiffusion, paper electrophoresis, and analytical ultracentrifugation. By the latter technique, an extrapolated sedimentation coefficient of 4.45S was determined. The further comparison of this antigen in immunodiffusion, along with an antiserum and the adrenal extract from the antiserum-providing animal, confirmed again that this is an autoantigen, and that it is one of five autoantigens of the adrenal gland. [ABSTRACT FROM AUTHOR]

The article presents a list of forthcoming papers related to immunology including "Epicutaneous Immunization Converts Subsequent and Established Antigen-specific Th1- to Th2-type responses," by Jessica Strid, Robin Callard and Stephan Strobel, "Variation and Infectivity Neutralization in Influenza," by Marcel Knossow and John Skehel and "Essential Role of Neutrophils in anti-type II collagen antibody and LPS-induced Arthritis," by Daisuke Tanaka, T. Kagari, H. Doi and T. Shimozato.

In the previous paper we showed that the immune response to sheep red cells (SRBC) was degenerate; serum antibodies showed increasing loss of specificity, signalled by cross-reactions with horse RBC (HRBC), with time after immunization and with hyperimmunization. In the present report we have analysed the role T cells may play in this process. To do this we studied the antibodies made by mice deprived of T cells by irradiation as well as those made by normal mice immunized with SRBC in distilled water, which was shown to depress the DNA synthetic response of T cells. In both instances the mice with fewer responding T cells made less antibody which could agglutinate HRBC than did the appropriate controls. This was true even when no difference in anti-SRBC titre was apparent. In addition we showed that the antibody made by mice with reduced numbers of T cells was less effective at passive suppression of the immune response to SRBC than was similarly titred (against SRBC) antibody made by normal mice. Thus, certain sub-populations of antibodies, normally made in response to SRBC, immunization, are particularly thymus dependent. We have discussed why we think they are those of particularly high affinity. [ABSTRACT FROM AUTHOR]

In this paper, we describe the results of experiments designed to test the hypothesis that immunogenic synthetic peptides representing non-immunodominant B- and T-cell epitopes of measles virus (MV) proteins can overcome the suppressive effect of maternal antibodies and induce anti-MV antibodies in young mice in the presence of maternal antibody to the virus. We have established a mouse model of immunosuppression by maternal antibody of both anti-MV and anti-peptide antibody responses in the young. Results obtained with this model immunization of young mice with a cocktail of synthetic peptides can overcome the suppression by maternal anti-MV antibodies and results in the induction of anti-peptide antibodies which recognize the virus. This work indicates that appropriately selected synthetic peptides have potential as vaccines which can be immunogenic and induce antibodies reactive with the virus-virus antibodies. in the presence of maternal anit-virus antibodies.

Lymph node and spleen cells from normal mice were cultured for 3 days with polyoma virus-induced tumour, Ehrlich's ascites turnout or leukaemia L 1210 cells. This resulted in in vitro immunization of the lymphocytes, which were then transferred to irradiated target cells labelled with 51Cr. Normal, i.e. non-immune thioglycollate-stimulated peritoneal macrophages were also added to some tubes. Non-immune macrophages mixed with immunized lymphocytes showed a significantly increased ability to destroy tumour ceils as compared with macrophages in the absence of immunized lymphocytes. The immunized lymphocytes were almost entirely inactive alone. When the number of macrophages was kept constant the cytotoxicity was dependent on the number of viable immunized lymphocytes placed on the target cells. Immunized lymphocytes, in the presence of macrophages, only exhibited strong killing of the target cells against which they had been immunized; some lysis of ‘bystander’ cells was, however, seen provided specific target cells were present. Macrophage monolayers exposed to immunized lymphocytes upon contact with specific antigen became ‘armed’ and showed a significant cytotoxicity for specific target cells. When immunized lymphocytes and normal macrophages were treated with actinomycin D and puromycin, cytotoxicity was inhibited in the immunized lymphocytes but not in the macrophages. The possible mechanism of normal macrophage cooperation with immunized lymphocytes in the cytotoxic killing reaction is discussed. Results presented in this paper favour the view that immunologically specific cytophilic factor (presumptive cytophilic antibody) is involved in the macrophage-mediated cytotoxicity in the system studied. [ABSTRACT FROM AUTHOR]

An earlier paper showed that 4 days after immunization with the contact sensitizing agent 'uxazolone' there is a peak in the percentage of cells in the draining lymph nodes that move to sites of inflammation. This was assessed by dissociating the lymph nodes, labelling them with 51Cr and injecting them into mice whose ears were painted within an hour with an unrelated contact sensitizing agent or with croton oil. The ears were then removed at about 18 hours and their radioactivity used as a measure of cell arrival. The cells that move to sites of inflammation are not macrophages as they are not removed by filtration through cotton wool. They are θ-positive and control studies show that the activity of the anti-B serum was indeed due to antibody to the θ-antigen. The cells are large and can be labelled both in vivo and in vitro with [125I]-iododeoxyuridine which is incorporated in the DNA of cells during the S phase of the cell mitotic cycle. It was concluded that the cells in immunized lymph nodes that move to sites of inflammation are T blasts. The unitary hypothesis is put forward that following immunization for delayed hypersensitivity a particular class of T cells proliferates and gives rise to large pyroninophilic blast cells; and that these cells or their immediate descendants possess the properties, either at the same time or at closely related times, of' movement to sites of inflammation and non-specific cytotoxicity as well as the capacity to passively transfer cellular immunity. [ABSTRACT FROM AUTHOR]

This paper examines helper T-cell responses and antibody titres and isotypes following immunization with a peptide antigen in association with three different adjuvants. B10.A mice were primed with pigeon cytochrome c fragment 81-104 in association with the adjuvants complete Freund's adjuvant (CFA), incomplete Freund's adjuvant (IFA) and alum. Strong antibody responses, dominated by IgG1, were observed upon priming with CFA and IFA. In contrast, priming with alum induced a weak antibody response with little or no detectable antigen-specific IgG1. These differences did not correlate with differences in T-cell priming, as immunization with peptide in association with all three adjuvants induced comparable T-cell proliferative responses and frequencies of antigen-specific cells. In addition, no significant differences in iiiterleukin-2 (IL-2), interferon-gamma (IFN-γ) and IL-4 production could be found, suggesting that the adjuvants did not differentially affect Th1 and Th2 cells. [ABSTRACT FROM AUTHOR]

Thirty-six guinea pigs were injected with a suspension of pooled guinea-pig adrenals incorporated into Freund adjuvants; twenty-two rabbits were immunized in a similar manner with rabbit adrenal suspensions. Sera of twenty-six guinea pigs and twelve rabbits reacted in complement fixation and tanned cell haemagglutination tests with adrenal extracts but not with extracts of other organs. Potent antisera also produced one line reaction in double diffusion gel precipitation test with adrenal extracts. The adrenal-specific antigen was thermolabile, possibly of protein character. Reactions of guinea-pig antisera were limited to guinea-pig adrenal; rabbit antisera reacted with adrenal of all tested mammalian species. The serological reactions exhibited by antigens prepared from the antibody producer's own adrenal were as strong as those produced by adrenals of other animals of the same species. Additional evidence for auto-specificity of the antibody under investigation was obtained from the experiment in which a guinea pig injected with its own gland removed by left adrenalectomy formed adrenal antibodies. Some but not all animals developed histological lesions in the adrenal gland. The interpretation of this observation was complicated by occasional positive histological findings in the adrenals of control animals. [ABSTRACT FROM AUTHOR]

Delayed footpad reaction against syngeneic testicular cells was compared between males and virgin females of C3H/He mice. Mice were immunized subcutaneously with 1 × 107 of syngeneic testicular cells and the reaction was elicited with 1 × 106 of syngeneic testicular cells 6 days after the immunization. When mice were pretreated with 0, 25 or 50 mg/kg of cyclophosphamide (CY), the delayed footpad reaction was detected in female mice, but not in male mice under the same conditions. This sex difference in the reaction to testicular cells was not attributed to the recognition of H-Y antigen by female mice. A sex difference in the reaction to sheep red blood cells (SRBC) was not observed. The sex difference in the reaction to testicular cells was attributed to testicular cells other than sperm because a sex difference was not detected against sperm. The implications of these findings are discussed in relation to the tolerance phenomena of autologous testicular cells. [ABSTRACT FROM AUTHOR]

The regulation of secondary antibody production in mice is studied in adoptive transfer experiments. Mice immunized twice with chicken red blood cells (CRBC) in Freund's complete adjuvant (adjuvant) at 28 day intervals subsequently produce high levels of IgG anti-CRBC antibody for several weeks. Immunization with CRBC in saline also induces prolonged splenic production of IgG antiCRBC antibody but at a much lower level. It was not possible to augment the level of antibody production in mice immunized with CRBC in saline by transfer of very large numbers of spleen cells from mice immunized with CRBC in adjuvant. Transfer experiments in the opposite direction failed to suppress antibody responses in mice immunized with CRBC in adjuvant. Similar experiments were carried out with mixed transfers into third party non-immune irradiated recipients. The requirement for continued antigen supply to maintain secondary antibody production was shown in that IgG anti-CRBC antibody production in nonimmune recipients of immune spleen cells ceased within five days when the recipients were not given antigen. It is concluded that: (i) while strong regulation of secondary antibody production against CRBC exists, this is not a function of transferrable suppressors; (ii) increased antibody production in animals treated with adjuvant is not due to increases in the number of antigen-sensitive T or B lymphocytes; and (iii) the data are most easily explained by a hypothesis which implicates the rate of triggering of lymphocytes as the regulatory step in secondary antibody production. This could be a factor relating to the supply of antigen or the number of sites in secondary lymphoid tissue at which antigen can trigger. [ABSTRACT FROM AUTHOR]

The bone marrow of young adult nude mice was investigated as a site of antibody formation after intravenous immunization with the thymus-independent antigen Escherichia coli lipopolysaccharide (LPS). Mice heterozygous for the nu-gene were found to be capable of a plaque-forming cell (PFC) response in both spleen and bone marrow after primary and secondary immunization with LPS. Primary immunization of nude mice with LPS induced a normal PFC response in the spleen, but did not evoke the appearance of PFC in the bone marrow. During the secondary response the nude mice did show PFC activity in the bone marrow, but at a much lower level than their heterozygous littermates. At all time points after secondary immunization the number of splenic PFC was higher in nude mice than in the control mice. Determination by immunofluorescence of cells containing cytoplasmic immunoglobulin (C-Ig cells) in the bone marrow of young adult nonimmune nude and heterozygous mice, revealed a three times higher number of C-IgM cells in the bone marrow of the heterozygous thymus-bearing mice. On the other hand, the number of splenic C-IgM cells was higher in the nude mice than in their heterozygous littermates. These results suggest that the presence of the thymus facilitates the appearance of mature antibody-forming cells in the bone marrow of young adult mice, irrespective of whether the generation of these cells is initiated by so called thymus-dependent or thymus-independent antigens. [ABSTRACT FROM AUTHOR]

A state of protein-overloading paralysis has been induced to bovine γ globulin (BGG) in adult CBA mice. Paralysis was demonstrated by a lack of immune elimination of 131I labelled BGG after prior challenge with Freund's adjuvant containing BGG. The degree of paralysis was found to diminish when the time between the paralysing injection and challenge injection was increased. This loss of the paralysed state could be prevented by injections of antigen whilst the mice were still paralysed. The superficial nature of the differences between paralysis (unresponsiveness induced in adults) and tolerance (unresponsiveness induced in neonatals) to BGG in CBA mice is discussed. The possibility that suppression of antibody production in previously immunized animals given a massive dose of antigen, is a distinct phenomenon from the induction of paralysis/tolerance in animals not previously immunized, is briefly discussed. [ABSTRACT FROM AUTHOR]

Peritoneal exudate lymphocytes (PEL) of guinea-pigs injected with Freund's complete adjuvant (FCA) were capable of liberating skin reactive factor (SRF) and macrophage migration-inhibitory factor (MIF) when cultured for 24 hours in the presence of sheep red cells (SRC) preincubated with lymph node cells (LNC) of guinea-pigs immunized with SRC in FCA. Similar release of soluble mediators was found in the following situations: (a) incubation of non-immune PEL with SRC sensitized with the exclusion peak of Sephadex G-200 fractionated immune LNC supernatant; (b) incubation of non-immune LNC with complexes of SRC and anti-SRC IgG, prepared from serum of animals immunized with SRC in CFA, and (c) incubation of non-immune LNC with a mixture of SRc urea extract and anti-SRC IgG. SRC incubated for 24 hours with immune LNC and freed of lymphocytes by selective filtration through a Millipore filter, were able to provoke an inflammatory reaction in the skin of normal guinea-pigs, which was delayed in character. These findings are interpreted as suggestive evidence for the non-identity of the mediator-producing and antigen-reactive cells and as support for the hypothesis that a complex composed of antigen and an antibody-like material, secreted by stimulated antigen-reactive lymphocutes, is responsible for the release of soluble mediators in cell-mediated immune reactions. [ABSTRACT FROM AUTHOR]

A complete evaluation of the immunogenicity of oligo-L-lysines and their mono-ε-DNP derivatives requires a determination of their capacity to prepare animals for secondary responses to a highly immunogenic analogue and to elicit secondary responses in animals prepared with such an analogue. It is shown here that 1-ε-DNP-tetra-L-lysine is not effective, or only marginally effective, in preparing PLL+ guinea-pigs for secondary anti-DNP responses to DNP-poly-L-lysine whereas 1-ε-DNP-nona-L-lysine is active in such preparation. Similarly, in animals primed to DNP-ovalbumin, supplemental immunization with tetra-L-lysine is not effective in preparing strain 2 guinea-pigs for a secondary anti-DNP response to DNP-poly-L-lysine whereas both nona-L-lysine and poly-L-lysine are effective, the latter to a considerably greater degree. In animals primed with DNP-poly-Llysine or with DNP-ovalbumin and poly-L-lysine, DNP-poly-L-lysine elicits secondary anti-DNP responses whereas neither 1-ε-DNP-nona-L-lysine or 1-εDNP-tetra-L-lysine do. The data indicate that a hierarchy in the degree of immunogenicity exists within the lysyl peptides series with poly-L-lysine more immunogenic than nona-L-lysine and this, in turn, more immunogenic than tetra-L-lysine which is either nonimmunogenic or marginally immunogenic. Further, the determination of immunogenicity is a feature either of the 'helper' cell population or of a step in the response which is prior to the activation of 'helper' cells. [ABSTRACT FROM AUTHOR]

Lymph node cells from Black Hooded (BH) rats immunized with Freund's complete adjuvant (CFA) are only poorly cytotoxic to target cells treated with target cell specific antibody. Normal spleen cells are highly cytotoxic to antibody coated target cells. When 106 lymph node cells, from rats immunized with Chang cells in CFA, are mixed with 107 spleen cells from unimmunized rats, the mixture is 8.6 times more cytotoxic than the sum of the cytotoxicities of the two lymphoid cell populations alone. Immune lymph node cells were no more cytotoxic in the presence of 5 per cent fresh guinea-pig serum than in the presence of heat inactivated guinea-pig serum. Immune spleen cells are prevented from damaging target cells by antagonists of protein synthesis such as Puromycin. Puromycin, however, does not alter the cytotoxic effect of either immune or nonimmune spleen cells on antibody coated target cells. From these experiments it is tentatively suggested that lymphoid cells from immunized animals mediate target cell damage by a reaction involving firstly immunologically specific responder cells which synthesise antibody and secondly non-specific effector cells which damage the antibody coated target cells. Evidence is presented which suggests that stable soluble factors may not be responsible for mediating target cell damage in this system. [ABSTRACT FROM AUTHOR]

Anti-haemagglutinin titres and measurements of the changes in the number of antibody molecules per millilitre (A), and in their average avidities (K) were carried out by equilibrium filtration on antisera prepared in rabbits to SW, MEL and LEE influenza viruses. These studies showed: (1) Immunization of rabbits with influenza virus by the intravenous route induced sufficient levels of antibodies by the 5th day after vaccination for testing by equilibrium filtration, immunization by the intraperitoneal or subcutaneous routes did not induce sufficient antibody levels for testing by the 5th day. (2) The avidity of the antibodies present at 5 days after vaccination was higher than at 10 days after vaccination. (3) The avidity of antibodies increased during the initial response period (from the low point at 10 days) and was independent of the routes or schedules of vaccination tested. (4) Secondary vaccination did not cause a pronounced increase in the avidity of antibodies, although a few groups of rabbits showed some further increase; tertiary vaccination caused no further increase. (5) The number of antibody molecules produced in rabbits after vaccination with influenza virus depended on the route and schedule of inoculation; the routes could be ordered intravenous, intraperitoneal and subcutaneous in decreasing order of efficiency; multiple doses increased the number of antibody molecules by all routes. (6) Increases in the antihaemagglutinin levels after secondary stimulation were due mainly to increases in the number of antibody molecules. [ABSTRACT FROM AUTHOR]

There is a current lack of effective mucosal vaccines against major gastroenteric pathogens and particularly against Helicobacter pylori, which causes a chronic infection that can lead to peptic ulcers and gastric cancer in a subpopulation of infected individuals. Mucosal CD4+ T-cell responses have been shown to be essential for vaccine-induced protection against H. pylori infection. The current study addresses the influence of the adjuvant and site of mucosal immunization on early CD4+ T-cell priming to H. pylori antigens. The vaccine formulation consisted of H. pylori lysate antigens and mucosal adjuvants, cholera toxin ( CT) or a detoxified double-mutant heat-labile enterotoxin from Escherichia coli (dm LT), which were administered by either the sublingual or intragastric route. We report that in vitro, adjuvants CT and dm LT induce up-regulation of pro-inflammatory gene expression in purified dendritic cells and enhance the H. pylori-specific CD4+ T-cell response including interleukin-17A ( IL-17A), interferon- γ ( IFN- γ) and tumour necrosis factor- α ( TNF- α) secretion. In vivo, sublingual immunization led to an increased frequency of IL-17A+, IFN- γ+ and TNF- α+ secreting CD4+ T cells in the cervical lymph nodes compared with in the mesenteric lymph nodes after intragastric immunization. Subsequently, IL-17A+ cells were visualized in the stomach of sublingually immunized and challenged mice. In summary, our results suggest that addition of an adjuvant to the vaccine clearly activated dendritic cells, which in turn, enhanced CD4+ T-cell cytokines IL-17A, IFN- γ and TNF- α responses, particularly in the cervical lymph nodes after sublingual vaccination. [ABSTRACT FROM AUTHOR]

C3H/HeN female mice were vaccinated with native Chlamydia muridarum major outer membrane protein ( MOMP), using Montanide+CpG or Alum+CpG as adjuvants. Negative control groups were immunized with ovalbumin (OVA) and the same adjuvants. As positive control, mice were inoculated intranasally with live Chlamydia. Mice were challenged in the ovarian bursa with 105 C. muridarum inclusion forming units. Six weeks after the genital challenge the animals were caged with male mice and monitored for pregnancy. Mice vaccinated with MOMP+Montanide+CpG developed high levels of C. muridarum-specific antibodies, with a high IgG2a/IgG1 ratio and neutralizing titres. Animals immunized using Alum+CpG had low antibody levels. Cellular immune responses were significantly higher in mice vaccinated with MOMP and Montanide+CpG, but not with Alum+CpG, when compared with negative controls. Following the genital challenge, only 20% (4/20) of mice vaccinated with MOMP+CpG+Montanide had positive vaginal cultures whereas 100% (9/9) of mice immunized with MOMP+CpG+Alum had positive cultures. Of the positive control animals inoculated with live Chlamydia only 15% (3/20) had positive vaginal cultures. In contrast, 100% (20/20) of mice immunized with OVA+CpG+Montanide, or minimal essential medium, had positive cultures. Following mating, 80% (16/20) of mice vaccinated with MOMP+CpG+Montanide, and 85% (17/20) of animals inoculated intranasally with live C. muridarum carried embryos in both uterine horns. No protection against infertility was observed in mice immunized with MOMP and CpG+Alum or OVA. In conclusion, this is the first time that a subunit vaccine has been shown to elicit a protective immune response in the highly susceptible C3H/HeN strain of mice against an upper genital challenge. [ABSTRACT FROM AUTHOR]

Intravenous immunoglobulin (IVIg) is successfully used in the treatment of autoimmune diseases involving self-reactive CD8+ T cells. However, its direct influence on the cytotoxic response remains unknown. Using an antigen cross-presentation assay and a mouse model of ovalbumin (OVA) immunization, we showed that IVIg decreases the in vitro activation, proliferation and cytokine secretion of OVA-specific CD8+ T cells (OT-I), as well as the in vivo generation of OVA-specific CD8+ T cells. In addition, IVIg significantly decreases the proportion of perforin- and CD107a-expressing CD8+ T cells, and inhibits the cytotoxic activity of OVA-activated OT-I cells. The interference of IVIg with the CD8+ T-cell response is associated with T-cell receptor blockade, therefore reducing the interaction between effector and target cells. A similar blockade is observed on human CD8+ T cells, suggesting that the observations reported here could apply to the IVIg-mediated improvement of CD8+ T-cell-mediated autoimmune conditions in human patients. [ABSTRACT FROM AUTHOR]

Summary Norovirus (NoV) -derived virus-like particles (VLPs) resemble empty shells of the virus and NoV P-particles contain only protruding domains of the NoV capsid. Both NoV-derived subviral particles show similar functionality and antigenicity in vitro and are considered to be potential vaccine candidates against NoV gastroenteritis. BALB/c mice were immunized with baculovirus-produced GII-4 VLPs or the corresponding Escherichia coli-produced P-particles by the intramuscular or intradermal route and the NoV-specific antibody and T-cell immune responses were compared. Elevated antibody levels were induced with a single VLP immunization, whereas P-particle immunization required a boost. High avidity antibodies were raised only by VLP immunization. VLP immunization resulted in a balanced T helper type 1/type 2 immune response whereas P-particles induced a T helper type 2-biased response. Only VLP immunization primed T cells for interferon-γ production. Most importantly, cross-reactive B and T cells were induced solely by VLP immunization. In addition, VLP antiserum blocked the binding of heterotypic VLPs to human histo-blood group antigen receptor and saliva. The findings in this study are relevant for the development of NoV vaccines. [ABSTRACT FROM AUTHOR]

Tuberculosis in mice is a lung disease. Airborne infection of this host species with Mycobacterium tuberculosis (Mtb) resulted in 20 days of Mtb growth in the lungs before further growth was inhibited and the level of infection stabilized. Inhibition of Mtb growth was associated with the production of interferon-γ (IFN-γ)-producing T cells in the lymph nodes and spleen and with the progressive accumulation of these cells in the lungs. Production of IFN-γ-producing T cells was not discernable until about day 15 of infection, presumably because Mtb did not disseminate from the lungs to the draining lymph nodes and spleen until after an approximate 10-day delay. By contrast, in mice infected via the intravenous (i.v.) route, the spleen became infected almost immediately, resulting in much earlier production of IFN-γ-producing T cells and earlier control of spleen and lung infection. In mice infected concurrently via both routes, earlier generation of immunity to the i.v. infection resulted in earlier accumulation of IFN-γ-producing T cells in the lungs and earlier control of lung infection that was initiated via the airborne route. This protection against airborne infection afforded by an earlier primary immune response is equivalent to that expressed by mice vaccinated with bacillus Calmette–Guérin or certain other vaccines. [ABSTRACT FROM AUTHOR]

The mechanism of the T-cell response and cytokine induction to restrict human immunodeficiency virus 1 (HIV-1) infection is not clear. During early infection, HIV-infected individuals have a high frequency of virus-specific cytotoxic T lymphocytes (CTLs) that effectively reduces the viral load. However, the CTLs are unable to clear the virus at later stages of infection, leading to disease progression. Dysregulation of cytokines like interleukin-12 (IL-12) and interferon-γ (IFN-γ) as a result of the interaction of HIV-1-specific T cells with antigen-presenting cells is one of the possible causes of CTL dysfunction. Secretion of IL-12 is reduced with the progression of HIV infection, correlating with impaired CTL function; however, the role of IL-12 in CTL regulation awaits elucidation. Here, we have studied the role of IL-12 in CTL dysfunction by using DNA immunization of wild-type (WT) and IL-12-deficient mice with HIV-1 gp120 complementary DNA. It was observed that the CTL response in IL-12-deficient mice was significantly less than that in WT mice. Our results further demonstrated that coimmunization with IL-12 vector restored the impaired CTL response in IL-12-deficient mice. However, immunization with IL-12 vector failed to rescue the CTL response in IFN-γ deficient mice, suggesting that the CTL-promoting function of IL-12 is IFN-γ-mediated. Our data suggest a phase-specific role of IL-12 in the CTL response, specifically in the priming of CD4+ T cells that provide help to CD8+ T cells. Our results also suggest that IL-12 is vital for the priming of antigen-specific T cells and plays an essential role in IFN-γ induction in T cells. [ABSTRACT FROM AUTHOR]

GD3, a ganglioside expressed on melanoma, is the only tumour-associated glycolipid described to date that can induce a CD1d-restricted natural killer T (NKT)-cell response. We analysed the fine specificity of GD3-reactive NKT cells and discovered that immunization with GD3 induced two populations of GD3-reactive NKT cells. One population was CD4+ CD8− and was specific for GD3; the other population was CD4− CD8− and cross-reacted with GM3 in a CD1d-restricted manner, but did not cross-react with GM2, GD2, or lactosylceramide. This indicated that the T-cell receptors reacting with GD3 recognize glucose-galactose linked to at least one N-acetyl-neuraminic acid but will not accommodate a terminal N-acetylgalactosamine. Immunization with GM2, GM3, GD2, or lactosylceramide did not induce an NKT-cell response. Coimmunization of GM3-loaded antigen-presenting cells (APCs) with GD3-loaded APCs suppressed the NKT-cell response to GD3 in a CD1d-restricted manner. This suppressive effect was specific for GM3 and was a local effect lasting 2–4 days. In vitro, GM3-loaded APCs also suppressed the interleukin-4 response, but not the interferon-γ response, of NKT cells to α-galactosylceramide. However, there was no effect on the T helper type 2 responses of conventional T cells. We found that this suppression was not mediated by soluble factors. We hypothesize that GM3 induces changes to the APC that lead to suppression of T helper type 2-like NKT-cell responses. [ABSTRACT FROM AUTHOR]

Since it was previously shown that protein antigens applied epicutaneously in mice induce allergic dermatitis mediated by production of T helper 2 (Th2) cytokines we postulated that this might induce suppression of Th1 immunity. Here we show that epicutaneous immunization of normal mice with a different protein antigen applied on the skin in the form of a patch induces a state of subsequent antigen-non-specific unresponsiveness caused by suppressor T cells (Ts) that inhibit sensitization and elicitation of effector T-cell responses. Suppression is transferablein vivobyαβ-T-cell receptor CD4+ CD8+ double positive lymphocytes harvested from lymphoid organs of skin patched animals and are not major histocompatibility complex-restricted nor antigen specific. Both CD25+ and CD25– CD4+ CD8+ T cells are able to suppress adoptive transfer of Th1 effector cells mediating cutaneous contact sensitivity.In vivotreatment with monoclonal antibodies showed that the cytokines interleukin (IL)-4, IL-10 and transforming growth factor-β (TGF-β) are involved in the induction of the Ts cells. Additionally, using IL-10–/– mice we found that IL-10 is involved in skin induced tolerance. Furtherin vitroexperiments showed that lymph node cells of skin tolerized mice non-specifically suppress[3H]thymidine incorporation by antigen-stimulated immune cells and this effect can be abolished by adding anti-TGF-β, but not anti-IL-4 nor anti-IL-10 antibodies. These studies indicate the crucial role of TGF-β in skin induced tolerance due to non-antigen-specific Ts cells and also show that IL-4, IL-10 and TGF-β play an important role in the induction of epicutaneously induced Ts cell suppression. [ABSTRACT FROM AUTHOR]

The relationship between the IgA antibody response in serum (total and polymeric IgA) and intestinal secretions was examined in volunteers subjected to oral and parenteral typhoid vaccination. After oral vaccination (three doses of 1011 live Ty21a vaccine given at 48-hr intervals), serum pIgA antibody to typhoid lipopolysaccharide (LPS) was detected in seven of the 14 subjects (46·4 ± 59 U,/ 100 μl, mean±SD). However, all 14 showed a significant intestinal IgA response (993±2516 and 9349 ± 6754 U/rag pie- and post-vaccine: t= 5·25. P= 0·0002). The level of pIgA antibody declined rapidly, whereas intestinal IgA antibody levels remained elevated. Serum pIgA antibody was also found after parenteral immunization (two doses of 5 × l08 heat-killed bacteria given 14 days apart to six subjects), but an intestinal IgA antibody response was detected in these individuals only after a subsequent course of the oral vaccine given I month after initial parenteral immunization. Changes in serum pIgA antibody followed those of total serum IgA antibody rather than those of intestinal antibody. The results indicate that a serum pIgA response can be induced by an antigenic stimulus delivered either orally or parenterally, whereas an intestinal IgA response is induced only by a local antigen stimulus, The regulation of serum pIgA and intestinal IgA appear to be independent. [ABSTRACT FROM AUTHOR]

Susceptibility to experimental autoimmune encephalomyelitis (EAE), which is an autoimmune disease inducible by immunization with a brain-specific antigen in complete Freund's adjuvant (CFA), is different among strains. In an attempt to resolve the immune mechanisms by which the difference in susceptibility to EAE is regulated, we re-estimated susceptibility of several strains of rats, and the frequency of antigen-reactive T cells in each strain was determined by limiting-dilution analysis. EAE was induced in Lewis (LEW), PVG/c and BN rats using four different methods: (i) active immunization with guinea-pig myelin basic protein (GPBP) in CFA; (ii) immunization with GPBP in CFA that had been further supplemented with Mycobacterium tuberculosis H37Ra (supplemented CFA); (iii) adoptive transfer of GPBP-activated spleen cells into syngeneic rats; and (iv) transfer of a GPBP-specific T-cell line. The LEW strain was susceptible to all four methods. The PVG/c strain was resistant to immunization with GPBP in conventional CFA (GPBP/conv. CFA), but was susceptible to immunization with GPBP in supplemented CFA (GPBP/suppl. CFA) and to transfer of activated spleen cells. The BN strain was resistant to all methods. Limiting-dilution analysis using T cells from LEW, PVG/c or BN rats has revealed that each strain of rat displays a different pattern of frequencies of GPBP-reactive or the 68–88 sequence (GP68–88)-reactive T cells. LEW rats showed relatively high frequencies of GPBP-reactive and GP68–88-reactive T cells after immunization with either GPBP/conv. CFA or GPBP/suppl. CFA, symptomatic rats showing higher values than asymptomatic rats. In asymptomatic PVG/c rats, the frequency of GP68–88-reactive T cells was lower than that of GPBP-reactive T cells. In PVG/c rats with clinical EAE, however, GP68 88-reactive T cells increased in frequency and were almost the same as GPBP-reactive T cells. BN rats, on the other hand, responded very poorly not only to the GP68–88 sequence but also to the whole GPBP molecule, even after immunization with GPBP/suppl. CFA. These findings, obtained by limiting-dilution analysis, strongly suggest that the development of EAE in LEW, PVG/c and BN rats is closely related to the frequency of GPBP-reactive T cells. Furthermore, it is shown that resistance to EAE found in PVG/c and BN rats may be generated by different immune mechanisms. [ABSTRACT FROM AUTHOR]

An auto-anti-IgE response was induced in conventional (PVG-RT1U and high IgE-producing (BN) rat strains by immunization with a highly purified rat IgE myeloma IR2. Earlier work established that total serum IgE levels were decreased by this procedure (Marshall & Bell, 1985) but only in the PVG-RTIU strain. IR2-immunized rats were tested for their ability to produce a specific IgE response to ovalbumin (OVA). The primary anti-OVA IgE response was inhibited by 60-75% in both rat strains, regardless of whether the total serum levels of IgE were reduced. The secondary IgE response to OVA was also inhibited in anti-IgE-producing animals but not in rats primed with OVA before anti-IgE induction. The inhibition of the anti-OVA response was isotype specific; the IgG response to OVA was unaffected. These studies may help elucidate the regulatory role played by naturally occurring anti-IgE antibodies found particularly in atopic individuals. [ABSTRACT FROM AUTHOR]

The intestinal immune response of mice against ovalbumin (OVA) was quantified by isolating lymphoid cells from the small intestine (SI) and testing them for antigen-specific immunoglobulin (Ig) secretion. The isolation procedure for functionally active lymphoid cells from the SI, originally developed to quantify the number of 'background' Ig-secreting cells in the SI, proved to be a useful method for evaluating antigen-specific intestinal immune responses quantitatively. The method was able to detect antigen-specific antibody-secreting cells (ASC) in the SI even when these cells occurred at a minimum frequency of only 0.006%. When mice were primed intraperitoneally (i.p.) with polymerized OVA and given an oral OVA booster immunization, OVA-specific ASC appeared in the SI from Day 3 after booster. After i.p. priming and an i.p. booster these cells could not be detected in the SI. The OVA-specific IgA--ASC responses in various organs after oral booster immunization were compared. From Day 5 after booster, when the response peaked, most OVA-specific IgA--ASC occurred in the SI. This suggested that these cells are mainly responsible for the OVA-specific antibodies demonstrated by ELISA in intestinal secretions from Day 6 after oral booster immunization. It is concluded that the quantitative method used in this study detects antigen-specific ASC in the SI with great sensitivity and could be used to evaluate immunization regimes aimed at inducing intestinal mucosal immune responses. [ABSTRACT FROM AUTHOR]

The spontaneous occurrence of antibodies against the Sm nuclear antigen is a highly specific marker for the diagnois of SLE. We have previously shown that anti-Sm can be elicited by immunization of SLE-prone mice with purified Sm antigen. In the present study, this autoanfibody was induced in normal mice by a similar immunization protocol. Anti-Sm produced by normal strains was predominantly IgG1, which is similar to the isotype distribution in Sm-immunized MRL mice, but unlike the IgG2a-dominated response seen for spontaneous anti-Sm. Anti-Sm raised by immunization in most strains recognized epitopes not seen by spontaneous human and murine SLE anti-Sm; of the eleven normal strains tested, only C3H and AKR, strains from which MRL was partially derived, responded to these determinants. Further, immunoblot analysis of anti-Sm generated by immunization of MRL and normal mice revealed that the same proteins recognized by spontaneous human and murine anti-Sm were also seen by these sera. This study shows that an autoantibody highly characteristic of SLE can be produced in normal and MRL mice after appropriate immunization, and that the fine specificity of such experimentally induced antibody can be similar to that of spontaneous anti-Sm autoantibodies. The results imply a role for autoimmunization with Sm in the production of anti-Sm. [ABSTRACT FROM AUTHOR]

Twenty-three monoclonal antibodies (mAbs) against Giardia muris were obtained in two fusions using spleen cells of immunized mice. Similarly, the fusion of mesenteric lymph node (MLN) cells of an infected mouse yielded 15 mAbs. Three mAbs arising from spleen cells and two from MLN (all five were IgM) were able to kill trophozoites in the presence of guinea-pig complement (GPC). They can agglutinate trophozoites and also impair the movement of the flagella in the absence of GPC. I.p. treatment of mice with mAb 45C on Days -1, 1.3 and 5 of infection significantly reduced the intestinal parasite burden. Indirect immunofluorescence assays on live and fixed trophozoites revealed that the cytotoxic mAbs were directed against antigens located on the periphery of the body, the sucking disc, the flagella and the ventro-lateral flange. In Western blots, our mAbs recognized major 36,200 and 30,300 MW glycoproteins located on the surface of the parasite. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies were produced following immunization of mice with live infective larvae of Brugia malayi. One of these, 46.08.76, is an antibody that promotes adherence of mouse peritoneal macrophages and human peripheral blood leucocytes to the infective larvae of B. malayi and Wuchereia bancrofti, respectively, and kills them. Fresh normal serum, as a source of complement, augments this effect. The same monoclonal antibody conferred 89% protection to jirds (Meriones unguiculatus) against challenge infection of B. malayi stage-three larvae. This monoclonal antibody recognizes antigens of 80,000, 67,000, 52,000 and 36,000 MW proteins present among the antigens of larvae, as detected by an immunoblotting technique. The antibody also reacts with antigens of infective larvae of Litomosoides carinii, Dipetalonema viteae and B. pahangi, but to a smaller extent. [ABSTRACT FROM AUTHOR]

Retinal S-antigen (S-ag), found in the rod photoreceptors of the eye, is a potent autoantigen that is commonly involved in inflammatory eye disease leading to blindness in man. Antibodies, induced in the experimental model by immunizing rats with S-ag purified from porcine retina, were used to prepare heterologous rabbit anti-idiotypic antibodies. The binding of the four rabbit anti-idiotypes to S-ag antibodies was partially inhibitable by porcine S-ag but not by ovalbumin. The idiotypic determinants were localized to the heavy chains by Western blotting with the anti-idiotypes. The presence of the idiotype recognized by the rabbit anti-idiotype was assessed in antisera from various species containing antibodies to S-ag. All rat sera from animals undergoing experimental autoimmune uveoretinitis by immunization with S-ag from porcine or bovine retina contained antibodies that react to varying degrees with the rabbit anti-idiotype. The intraspecies nature of the idiotypic determinants recognized was demonstrated by the fact that none of the anti-idiotypes showed any reactivity with rabbit or murine antisera to S-ag from porcine, bovine or human retina or to human autoantibodies to S-ag from patients with inflammatory eye disease. Thus, all private and recurrent idiotypic determinants induced in rats by immunization with S-ag appear to be restricted to that species. [ABSTRACT FROM AUTHOR]

Anti-idiotope antibodies produced by mice immunized with a human IgG paraprotein complexed with various mouse monoclonal antibodies (McAbs) have been measured. All animals receiving more than one injection of the paraprotein (free or complexed with a mouse McAb) produced antibodies to the idiotypes of the paraprotein. Complexing with a McAb, especially an anti-Fc-γ McAb, enhanced the response. Antibodies to the idiotopes of mouse McAbs were more difficult to produce and their production was very dependent on the mode and schedule of the immunization. The best antisera were produced by mice receiving a course of injections of pre-formed complexes of the IgG paraprotein and McAbs. Four of five mice produced antibodies to the idiotopes of an anti-light chain McAb (C4) after a course of immunization (one primary plus four boosts) of an IgG-C4 complex. Two of the six mice receiving a similar course of injections of the paraprotein complexed with an anti- gamma McAb (A55) produced high titres of antibodies to A55 idiotypes. Responses were enhanced when complexes were prepared with a pool of McAbs. It is probable that the formation of large multi- cross-linked complexes containing the McAb under study is important in generating the response. Once a response is initiated, very high titres may be achieved. [ABSTRACT FROM AUTHOR]

The immunizing ability of immune complexes preformed between EA and EA-hyperimmune serum was investigated in adult rats. After immunization with complexes at equivalence, the pattern of suppressed IgE responsiveness was similar to that induced when a small volume of immune serum accompanied routine immunization. We have suggested that the underlying principle is the same, and that the IgE response can be regulated by immune complexes. The ability to influence an ongoing IgE response was determined by treating with complexes at various times after immunization. While the primary IgE levels were differentially affected, the most consistent suppression was seen at the secondary stage. The data suggest that a stage of B-cell differentiation has been interrupted and that IgE antibody-producing cells have been prevented from developing. [ABSTRACT FROM AUTHOR]

Recent work has shown that a relatively long-lasting suppression of egg albumin (EA)-specific IgE responsiveness occurs in the progeny of EA-immunized mother rats. This phenomenon can be duplicated by a course of EA-immune serum injections given to the neonatal progeny of normal mothers, and antigen-specific IgG was found to be the effective mediator. In order to elucidate further the mechanism of this selective suppression, the capacity of immune serum to suppress IgE responsiveness in adults was investigated. Pretreatment of adults with hyperimmune serum 3 weeks in advance of immunization was as effective as when the animals were neonatally treated. The possibility that the mediator responsible is the very small amount of EA-specific IgG remaining at the time of immunization was tested by injecting a small volume of immune serum simultaneously with immunization. This treatment also suppressed IgE responsiveness. The possibility that low levels of EA-specific antibody form complexes with the immunizing antigen is discussed. [ABSTRACT FROM AUTHOR]

Since anti-sperm antibodies were first discovered in the sera of women, the relationship of these antibodies to sterility has been studied by many investigators. In order to determine the antigens of spennatozoa responsible for raising antibodies to spermatozoa in humans, many studies have been carried out by purifying human spermatozoa cell membrane and seminal plasma components. Since it was found that the purification was difficult by physicochemical procedures, the immunoaffinity chromatography bound monoclonal antibody (Mab) to spermatozoa antigens was attempted for this purpose. The establishment of hybridomas producing Mabs to human seminal plasma and human spermatozoa was reported by Shigeta et al. (1980), Isojima, Koyoma & Fujiwara (1982), Lee a at (1982) and Isahakia & Alexander (1984). The ordinary approaches to obtain the Mabs consisted of xenogenic immunization with human semen and cell fusion of immunized spleen cells with mouse myeloma cells. However, the antigenic epitopes of human spermatozoa, which induced antibody production, are xenogenic for the mouse, and therefore there is a possibility that them is a difference in recognized antigenic epitopes in humans as isotypic and in mice as xenogenic. In order to study these antigenic epitopes, which correspond to antibodies against spermatozoa in women, the establishment of human-mouse hybridomas, which produced anti-semen antibodies as produced in sterile women, became essential. In these studies, we used recently developed cell fusion techniques to fuse immunized human peripheral lymphocytes with mouse meyloma cells. [ABSTRACT FROM AUTHOR]

The distribution of keyhole limpet haemocyanin (KLH)-specific helper cells for antibody responses of IgA, IgM and IgG isotypes in Peyer's patch (PP), mesenteric lymph node (MLN) and peripheral lymph node (PLN) was examined following oral, intraduodenal (ID), intraperitoneal (IP), intra- Peyer's patch (IPP) or subcutaneous (SC) immunization with KLH. Oral or ID immunization gave little or no response in any tissue studied. IP immunization with or without a subsequent ID challenge gave rise to a modest IgA and IgM helper response in MLN but a small IgA and IgM helper response in PP and PLN. IP immunization alone did not stimulate IgG-specific help in any tissues studied, but a small IgG helper response occurred in MLN and PLN after subsequent ID challenge. IPP was the most effective route of immunization, giving rise to a large helper response for IgA, IgM and IgG isotypes in PP, a smaller response in MLN and no response in PLN. The helper response following IPP immunization was not augmented by subsequent ID challenge. SC immunization gave a small but significant helper response for all isotypes in PLN but no response in PP or MLN. The kinetics of the helper response were examined in PP. MLN, PLN and thoracic duct lymph (TDL) following IPP immunization. The helper response for all isotypes in PP was maximal at 2 weeks and then declined. Similar kinetics but of lower magnitude were observed in MLN and TDL. The presence of IgA- specific helper cells in TDL demonstrates that these cells migrate, presumably from GALT, and may constitute an important component of mucosal responses at extraintestinal sites. [ABSTRACT FROM AUTHOR]

Sex reversed X/X male mice carrying Sxr or the variant Sxr' were typed for expression of the male specific histocompatibility antigen H-Y, by skin grafting and by in vitro cytotoxic and proliferative tests. The X/XSxr males, like X/Y males, were Hey positive by in vitro testing, and failed to reject semiesyngeneic male skin grafts. In contrast X/XSxr' males, like xix females, were H-Y negative and rejected semi-syngeneic, male skin. Spleen cells from X/Y males sensitized C57BL/10 female recipients to reject syngeneic male skin rapidly, whilst immunization with X/X female or X/XSxr' male cells failed to stimulate such second-set responses. These data suggest that the H-Y antigen detected by cytotoxic T cells is the same as that detected by graft rejection responses, that the Sxr' variant is not a tissue-specific regulatory mutation, and that X/XSxr' individuals do not express H-Y antigen but nevertheless develop as phenotypic males. [ABSTRACT FROM AUTHOR]

The intravenous injection of hapten-modified (picrylated) cells causes unresponsiveness. When conventional or recombinant interleukin-2 (IL-2) is also injected, strong contact sensitivity occurs. This IL-2 is effective when given 7 hr after the injection of the picrylated cells or 2 days later, hut has no effect when given beforehand. It is suggested that picrylated cells given intravenously fail to induce contact sensitivity secondary to a failure of IL-2 production, and that IL-2 may be one of the second signals which converts a 'tolerogenic' stimulus into an immunogenic stimulus. [ABSTRACT FROM AUTHOR]

The contribution of gut-associated lymphoid tissue (GALT) to the local response in the mammary gland is well documented in laboratory animals and has been evaluated in this study in ruminants. Ewes were immunized intraperitoneally (IP) with antigen in Freund's complete adjuvant (FCA), a procedure which stimulates the production of anti- bodies of the IgA class in the intestine, and challenged intramammarily (IMam) either during colostrum formation or mammary gland involution. Despite a substantial IgA antibody-containing cell (ACC) response in the intestine in IP immunized sheep, there was no evidence to suggest a relocation of IgA-specific ACC to the mammary gland. There was, however, an IgA antibody response in mammary secretion of IP immunized animals, regardless of whether the mammary gland was locally immunized, but the origin of this antibody is unclear. IP/IMam immunized sheep did have an enhanced antigen-specific ACC response of the IgGI isotype in locally immunized glands. but whether these cells were of GALT or systemic origin is also unclear. [ABSTRACT FROM AUTHOR]

The hypervariable regions of the immunoglobulin molecule which function as the antigen-combining site are, themselves, capable of provoking an antibody response. These antigenic determinants on the immunoglobulin are termed the `idiotype', and antibodies directed against them `anti-idiotype'. In circumstances where there is a close complementarity of shape between antigen and idiotype, and subsequently between idiotype and anti-idiotype, it would be predicted that anti-idiotype would be like an `internal image' of the antigen. Starting with a monoclonal antibody (idiotype) to the protective a determinant of the hepatitis B surface antigen (HBsAg), we have succeeded in raising two monoclonal anti-idio-types which mimic HBsAg in their ability to bind polyclonal antibodies to HBsAg produced in a variety of species. These internal image anti-idiotypes may provide a strategy for immunization without the need for antigen. [ABSTRACT FROM AUTHOR]

Experiments were carried out to determine the effect of a range of adjuvants on the antibody response of sheep to a subcutaneous injection of ovalbumin. Incomplete Freund's adjuvant (IFA) was the best of the repository type adjuvants. From a range of soluble immunopotentiating substances tested, the polyion DEAE-dextran, or dextran sulphate, produced the greatest enhancement of the response. These results were confirmed in a factorial experiment, but no interactions were found between various classes of adjuvants. Further experiments were carried out to determine the effect of superior adjuvants, prior immunization or intradermal injection on the rate and mode of uptake of antigen from the injection site to afferent lymph. These experiments showed that, with IFA, most antigen is retained at the injection site, less than 15% entering lymph by 3 days. There was some delay in antigen uptake with adjuvant 65, while for aluminium phosphate precipitated antigen, the rate of uptake was the same as following a saline injection. There was some delay in uptake of antigen following injection with DEAE-dextran or in primed sheep but, following intradermal injection, the rate of uptake into lymph was the same as aqueous antigen injected subcutaneously. Experiments in which the distribution of radioactive antigen between cells and plasma in lymph was examined showed that, in unprimed sheep, virtually all antigen is unassociated with cells. In primed sheep, however, about 0.5% of antigen in lymph was found to be cell-associated. Gel filtration of lymph plasma from primed sheep demonstrated that nearly all the antigen in lymph is carried to the node as high molecular weight material, presumably antigen-antibody complexes. [ABSTRACT FROM AUTHOR]

Although there is IgG subclass restriction in the antibody responses to most antigens, our data indicate that the human IgA subclasses, IgA, and IgA2, do not demonstrate a similar antigen specific restriction. We did not find evidence for IgA subclass restriction in the antibody responses to phosphorylcholine (PC), β lactoglobulin or tetanus toxoid. These antigens were chosen to represent carbohydrate-like versus protein antigens and antigens presented through the mucosal route versus the humoral route. For each of these antigens the proportion of antigen specific IgA that was IgA1 and IgA2 was similar to that of total serum IgA. IgA anti-PC, which is thought to be directed against the phosphorylcholine moieties found on certain bacterial polysaccharides, could be found in the serum of all individuals tested and constituted 0.062–0.088% of the total serum IgA. IgA anti-β lactoglobulin and anti-tetanus toxoid could be measured only in the serum of selected individuals, usually those with known milk protein sensitivity, or those recently immunized with letanus toxoid. The lack of a marked subclass restriction of IgA responses to these antigens stands in contrast to results obtained by others for IgG antibodies, in which carbohydrates and proteins preferentially stimulate antibodies in different IgG subclasses. [ABSTRACT FROM AUTHOR]

The contribution of gut-associated lymphoid tissue (GALT) to the local immune response in the respiratory mucosa of sheep has been investigated. Sheep were primed intraperitoneally (i.p.) with antigen in Freund's complete adjuvant, a procedure known to produce a large IgA-specific antibody-containing cell (ACC) response in intestinal lymph. ACC and their class specificity were then enumerated by double fluorochrome immunofluorescence in respiratory tissues after intratracheal (i.t.) antigen administration. This immunization procedure produced an enhanced IgA-specific ACC response in the upper respiratory tract mucosa compared with either i.t. or i.p. immunization alone and this was not reflected in the regional lymph nodes. Furthermore, chronic drainage of the intestinal efferent lymphatic duct for the duration of the immunization period abrogated the enhanced response in the respiratory mucosa. These data are consistent with the concept of an intermucosal cell circuit with respect to IgA cell precursors, and provide indirect evidence that IgA responses in the respiratory tract can be enhanced by harnessing the immune potential of GALT as a source of IgA precursors by appropriate immunization strategies. [ABSTRACT FROM AUTHOR]

In the T suppressor circuit which affects contact sensitivity, the T acceptor cell trace) armed with T suppressor factor (TsF) and then triggered by antigen and major histocompatibility complex products (I-J) releases non-specific inhibitor (nsINH). These non-specific inhibitor(s) affect both the efferent and afferent stage of the contact sensitivity reaction and were originally detected by the inhibition of the passive transfer of contact sensitivity. The nsINH also blocks the induction of contact sensitivity when given intravenously at the time of immunization but has no effect when given at the time of challenge. Similarly, it blocks proliferation in the regional lymph nodes induced by contact sensitizer in a dose-dependent fashion; it acts when given at the time of immunization but not 1 day later. This effect is antigen non-specific and H-2 unrestricted. The nsINH bears I-J determinants as shown by affinity chromatography on monoclonal antibody. The nsINH comes from the Tacc and is not a breakdown product of the TsF. This is shown by the fact that, when the Tacc and TsF have I-J of different genotypes, the genotype of the nsINH corresponds to that of the Tacc. Parallel measurements of inhibition of lymphoproliferation and of passive transfer show that the nsINH has a molecular weight of 50-60 Kd and a pi around 6.8 and suggest that similar or identical molecules block both the afferent and efferent stage of the contact sensitivity reaction. [ABSTRACT FROM AUTHOR]

Antigen-specific T helper factor appears in the 24 hr supernatant of lymph node cells taken 4 days after immunization with contact sensitizer. The factor is assayed by its ability to augment the contact sensitivity response induced by haptenized spleen cells. In practice, picrylated or oxazolonated spleen cells are treated with the factor for 1 hr at 4° and 4 × 106 cells are injected into the footpads of recipient mice. Contact sensitivity is assessed 5 days later. The factor first appears 3 days after immunization and its production depends on an Lyt-1+2-, I-A+, I-J- T cell. It is antigen-specific in its action in a criss-cross experiment, and can be absorbed with and eluted from haptenized beads. It bears I-A determinant(s) and the I-A determinant and the antigen binding site(s) occur on the same molecule. The molecular weight is around 60,000. The possible role of T helper factors in the activation of the antigen-presenting cell in the induction stage of the immune response is discussed. [ABSTRACT FROM AUTHOR]

Cytotoxic cell activity directed against paternal alloantigens was investigated in primiparous C57BL/10 and CBA/Ca mice using a microcytotoxicity assay. Most allogeneically or syngeneically mated females lacked effector cells in their spleens or paraaortic lymph nodes both during pregnancy and immediately postpartum. However, spleen, cells from 33% of C57BL/10 females mated to CBA/Ca males exhibited low levels of paternal target cell killing (P<0·05–0·01). Alloimmunization of virgin mice prior to mating resulted in only allogeneically mated females producing cytotoxic cells and alloantibody. These responses were not detectable during pregnancy bat appeared immediately postpartum. The ability of pregnancy to induce memory cell formation was tested by allowing females one successful pregnancy before challenging them postpartum with allogeneic spleen cells. Kinetic studies of cytotoxic cell production showed that C57BL/10 females that had borne (C57DL/10 × CBA/Ca)F1 litters responded earlier than their syngeneically meted sisters giving a peak response at 4 days compared to 7 days after immunization. This indicates that a single allogeneic pregnancy can prime the mother against paternal alloantigens suggesting that the conceptus is weakly immunogenic. [ABSTRACT FROM AUTHOR]

Lymphocytes bearing receptors for the Facb fragment of IgG have been shown previously to be elevated in the peripheral blood of patients with rheumatoid arthritis. The generation of these cells and their possible functional role in immune regulation have been investigated in mice. Facb rosette-forming (Facb-R+) lymphocytes were found to be elevated in the spleens of mice mounting a secondary plaque-forming cell (PFC) response to sheep erythrocytes but not during the primary response. Splenic Facb-R-lymphocytes were also elevated when a cross-reacting antigen (goat erythrocytes) was used for the secondary immunization but not when a non-cross-reacting antigen (chicken erythrocytes) was used. Both primary and secondary immunization with bacterial lipopolysaccharide resulted in elevation of splenic Facb-R+ lymphocytes. Administration of antigen-specific Facb fragment in conjunction with antigen (calf erythrocytes) produced a suppression of the secondary PFC response. However, F(ab′)2 fragments produced no such effect. This suppressive effect was shown to be antigen-specific since administration of Facb fragment of anti-calf erythrocyte IgG had no suppressive effect on the secondary PFC response to sheep erythrocytes. No change in splenic Facb-R+ lymphocytes was observed during delayed hypersensitivity responses to either sheep erythrocytes or the contact-sensitizing agent oxazolone. These results indicate that Facb-R+ lymphocytes are generated during secondary humoral responses bat not cell-mediated immune responses, and suggest that these cells may exert a suppressive influence on antibody production. These findings are discussed in relation to the occarrence of these cells in patients with rheumatoid arthritis. [ABSTRACT FROM AUTHOR]