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Grass pollen allergens are shown to remain associated with protein material and a yellow pigment during paper chromatography and during dialyses and ultrafiltrations of various types. Dialysable* allergens comprise only a fraction of I per cent of the total activity and the amount of activity extractable by diethylene glycol (DEG) and similar solvents is of the same order. Besides the allergens, the DEG and aqueous extracts contain large amounts of inositol, glucose and fructose, also some yellow pigments and phosphates. Larger amounts of free and combined amino acids are found in the aqueous than in the DEG extracts, but the reverse is true for sucrose. In addition the DEG extracts contain a yellow glucoside different from the dactylen of the aqueous extracts, a glucosan and an arabinose-galactose-pigment complex, only the latter being associated with any activity. The spontaneous release of the crystalline dactylen from originally clear aqueous pollen extracts is found not to be caused by enzymes. The washed crystals are found to be chromatographically and electrophoretically homogeneous and devoid of allergenic activity. [ABSTRACT FROM AUTHOR]

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]

Systemic lupus erythematosus (SLE) is characterized by the production of pathogenic autoantibodies with nuclear antigen (nAg) specificity. Using (SWRxNZB)F1 (SNF1) mice, we showed higher levels of Immunoglobulin A (IgA) production in the intestine and the nAg reactivity of faecal IgA under lupus susceptibility. Here, we determined whether the faecal IgA abundance and nAg reactivity are higher in, different among, various lupus‐prone preclinical models (MRL/lpr, NZBxNZW‐F1, SNF1, NZM2410 and NZM2328). We also determined whether the faecal IgA nAg reactivity at preseropositive ages correlates with the eventual serum autoantibody levels in males and females of these mouse models. We show that age‐dependent increase in the abundance and nAg reactivity of faecal IgA can vary among different lupus‐prone mouse models. Importantly, faecal IgA in these mice show significant levels of nAg reactivity, starting as early as at juvenile age. Furthermore, the pre‐seropositive stage nAg reactivity of faecal IgA in most lupus‐prone strains correlates well with that of eventual, seropositive stage systemic autoantibody levels. Gender differences in serum autoantibody levels were preceded by similar differences in the faecal IgA abundance and nAg reactivity. These observations suggest that faecal IgA features, nAg reactivity particularly, could serve as a biomarker for early prediction of the eventual systemic autoimmunity in lupus‐prone subjects. [ABSTRACT FROM AUTHOR]

New short-lived strains of mice (SAM-P), which have been developed by Takeda et al. (1981), show a defective antibody response to T dependent (TD) antigen in vitro, as demonstrated in the accompanying paper (see page 419). In the present study, we investigated the cellular site of the defect, using a cell culture system. In this paper, it is demonstrated that T-helper (Th) cell activity for the antibody response to TD antigen is impaired, while other cellular immune responses, e.g. mixed leucocyte reaction, cytotoxic T-lymphocyte response, and delayed-type hypersensitivity reaction, are normal. These results suggest that the defect in T-helper subset is limited in helper function for the antibody response, and that the helper function for the cell-mediated immune responses is intact. These two functions of the T-helper subset are apparently regulated in a different manner. The SAM-P strains of mice may thus serve as an appropriate model for studying functional heterogeneity in T-helper/inducer cell subsets. [ABSTRACT FROM AUTHOR]

Summary: Hepatocellular carcinoma (HCC) is the most common type of liver cancer with limited treatments. Asia has the highest HCC incidence rates; China accounts for over 50% of all HCC cases worldwide. T‐cell receptor (TCR) ‐engineered T‐cell immunotherapies specific for human leukocyte antigen (HLA) ‐A*02:01‐restricted α‐fetoprotein (AFP) peptide have shown encouraging results in clinics. HLA‐A*24:02 is more common than HLA‐A*02:01 in Asian countries, including China. Here we identified a novel HLA‐A*24:02‐restricted peptide KWVESIFLIF (AFP2–11) located in AFP signal peptide domain by mass spectrometric analysis of HLA‐bound peptides from HepG2 cells. A TCR (KWV3.1) specific for AFP2–11‐HLA‐A*24:02 was isolated from peripheral blood mononuclear cells of a healthy donor. The binding affinity of soluble KWV3.1 to its antigen was determined to be ~55 μm, within the affinity range of native TCRs for self‐antigens. KWV3.1‐transfected T cells could specifically activate and kill AFP2–11 pulsed T2‐A24 cells and AFP+ HLA‐A*24:02+ tumor cell lines, demonstrating that AFP2–11 can be naturally presented on the surface of AFP+ tumor cell lines. The newly identified antigenic peptide can provide a novel target for immunotherapeutic strategies for patients with AFP+ HLA‐A*24:02+ HCC. [ABSTRACT FROM AUTHOR]

Ammonium sulphate precipitation and DEAE chromatography is an efficient way of purifying Ag 11, the main allergen in Dermatophagoïdes farinae mites, which has already been characterized by crossed radioimmunoelectrophoresis. At 60% of saturation in ammonium sulphate, a precipitate is formed which, dissolved and dialysed has been named fraction A 60. It is mainly composed of Ag 11. In the fraction DE obtained by DEAE chromatography of the ammonium sulphate fraction A 60, Ag 11 appears homogeneous on crossed-immunoelectrophoresis. Isoelectrofocusing results indicate an average isoelectric point near neutrality in agreement with the non-absorbtion of Ag 11 on the DEAE cellulose at a weak ionic strength (0.01, at pH 7.2). By sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration Ag 11 has a molecular weight of 28,000. Ag 11 appears as a single polypeptidic chain with numerous dithio-bonds implying a highly folded and resistant structure. Oligosaccharides could be present as constituting molecules as well as contaminating ones as was assumed for henosamines. These results are discussed with reference to a similar study performed on the major allergen of Dermatophagoïtes pteronyssinus. The allergenic properties of Ag 11 as present in fraction DE were tested by RAST-based methods. Fraction DE is an inhibitor as good as Df 80d and when it is coated on paper discs it can bind specific IgE in sera from the majority of mite sensitive patients. The results suggest that Ag 11 is a major allergen from D. farinae. [ABSTRACT FROM AUTHOR]

In the preceding paper a population of lymphoid cells was identified which (1) were derived from germinal centres in the appendix, (2) were localized in follicular structures elsewhere, and (3) could perform as antibody-forming cell precursors. The present paper presents evidence (1) that germinal centres in the spleen and lymph nodes perform the same function as germinal centres in the appendix, and (2) that germinal centres are dependent upon a stream of cells derived from the bone marrow. A new hypothesis is put forward regarding the origin and cellular kinetics of the B-cell system in mammals. It is proposed that germinal centres throughout the body function as an essentially antigen-dependent amplification system for the B-cell population of lymphocytes. Implications of this hypothesis are discussed. [ABSTRACT FROM AUTHOR]

The fractionation of a partially-purified extract of Dermatophagoïdes farinae mite culture has been undertaken by gel filtration. Two fractions were isolated. One, P25, is a protein-rich fraction with mol. wt about 25,000. The other, GP8, is a polysaccharide-rich fraction with mol. wt around 8,000. By crossed immunoelectrophoresis, we detected eleven antigens in the partially-purified dialysed D. farinae extract (Df 80d) as well as in P25 fraction. One of them, ag 11, seems the most important allergen since in crossed-radio immunoelectrophoresis experiments it displays the faster radiostaining, implying that it binds the greatest part of the mite-specific IgE present in a pool of sera from mite-sensitive patients. By crossed-line immunoelectrophoresis, we demonstrated the absence of ag 11 in GP8, in which only ag 5 and ag 6 were identifiable. By radioalloergosorbent tests (RAST), it was found that P25- and GP8- coated paper discs can fix specific IgE induced in the majority of D. farinae sensitive patients. Defining a ‘major allergen’ as an allergen to which the majority of sensitive patients develop specific IgE, both P25 and GP8 do appear to contain at least one major allergen. By RAST inhibition method, using Df 80d as a solid phase, the allergenic activity of P25 appeared as slightly higher than that of Df 80d, whereas GP8 displayed a very weak inhibitor capacity. Thus, the allergic specificity of GP8 differs from that of Df 80d or P25. [ABSTRACT FROM AUTHOR]

Our earlier observations indicate that adoptive transfer of spleen cells obtained from dengue type 2 virus (DV)-primed mice suppressed DV antigen-specific antibody secretion as detected by Jerne PFC technique. Findings of this paper indicate that the suppression was produced by non-glass-adherent cells, macrophage-depleted (by carbonyl iron) cells and by T lymphocytes of the spleen but not by the glass-adherent cells and B lymphocytes. The activity of these cells is dependent upon production of prostaglandin as shown by abrogation of their suppressor activity by pre-treatment of cells by indomethacin or aspirin which are known to block synthesis of prostaglandins. [ABSTRACT FROM AUTHOR]

Heat and pH stability studies and experiments with organic solvents show that the A-antigens discussed in the preceding paper (Augustin, 1959c) are much more labile than the I-(‘inner ring’) antigens. Breakdown products and/or aggregates are produced which no longer precipitate with antisera to the original extracts, but act as inhibitors. Solutions of pollen allergens, on the other hand, are found to withstand even autoclaving for 15 min. at 20 atm. and vigorous boiling over the naked flame of a bunsen burner. None of the carbohydrates tested has a demonstrable effect on skin reactivity which is, however, destroyed by crystalline pepsin, crystalline trypsin, a crystalline mould protease and a tissue protease (a partially purified extract from rabbit spleen). It follows that the bulk of the allergens—if not all—are proteins. The relation of skin reactivity, immuno-electrophoretic patterns, carbohydrate and protein reactions to the selective destruction of the pollen antigens is investigated. Pollen components prove to have a somewhat wider range of electrophoretic mobilities than serum proteins and are probably as complicated a mixture. The most and least highly negatively charged components are without skin reactivity in allergic subjects. The skin reactive allergens appear to have the mobilities of α- and β-globulins. Not all the hay fever subjects react equally to all the components, and Cocksfoot and Timothy activity patterns vary in different subjects. [ABSTRACT FROM AUTHOR]

An antigen that can be derived from rabbit kidney can be identified by use of suitable rabbit antisera as being non-tissue specific in addition to being an autoantigen, since it had been found to be distributed in kidney, heart, adrenal and liver. The purification of this autoantigen has been accomplished by successive use of four different methods. These were the salting out with ammonium sulphate, gel filtration on Sephadex G-200, dialysis against distilled water, and chromatography on DEAE-cellulose. The heterogeneity of the products derived from the procedure at each step was analysed by means of analytical electrophoresis and ultracentrifugation, and also by gel diffusion precipitation. The final product was a homogeneous component, according to the criteria that were used. It had a sedimentation coefficient of 4.1S, suggesting a mol. wt of approximately 60,000. This autoantigen is of similar molecular size to several others that are, in contrast, adrenal specific or kidney specific. [ABSTRACT FROM AUTHOR]

Summary: Natural killer (NK) cells provide a major defence against human cytomegalovirus (HCMV) infection through the interaction of their surface receptors, including the activating and inhibitory killer immunoglobulin‐like receptors (KIRs), and human leucocyte antigen (HLA) class I molecules. Also γ marker (GM) allotypes, able to influence the NK antibody‐dependent cell‐mediated cytotoxicity, appear to be involved in the immunological control of virus infections, including HCMV. In some cases, their contribution requires epistatic interaction with other genes of the immune system, such as HLA. In the present report, with the aim of gaining insight into the immune mechanisms controlling HCMV, we have studied the possible associations among humoral and NK responses, and HCMV infections. In a previous study we assessed whether the KIR and HLA repertoire might influence the risk of developing symptomatic (n = 60) or asymptomatic (n = 60) disease after primary HCMV infection in the immunocompetent host. In the present study, the immunocompetent patients with primary symptomatic HCMV infection were genotyped for GM3/17 and GM23 allotypes, along with the 60 participants with a previous asymptomatic infection as controls. Notwithstanding the presence of missing data record, advanced missing data recovery techniques were able to show that individuals carrying the GM23 allotypes, both homozygous and heterozygous, GM17/17, HLA‐C2 and Bw4T KIR‐ligand groups are associated with the risk of developing symptomatic infection. Our findings on the role of both cellular and humoral immunity in the control of HCMV infection should be of value in guiding efforts to reduce HCMV‐associated health complications in the elderly, including immunosenescence, and in transplantation. [ABSTRACT FROM AUTHOR]

There is no doubt that HLA-DR molecules are acting as the products of HLA-linked immune response genes (Ir-genes), because (i) HLA-DR molecules are the restriction elements in the interaction between CD4+ helper T cells and antigen-presenting cells (APC) to respond to many antigens such as streptococcal cell wall antigen (SCW) (Nishimura & Sasazuki, 1983; Sone et al., 1985; Hizayama et al., 1986), schistosomal antigen (Sj) (Hirayama et al., 1987), Mycobacterium leprae antigen (ML) (Kikuchi et al., 1986) and so on; and (ii) anti-HLA-DR monoclonal antibodies completely abolish the immune response to those antigens (Nishimura & Sasazuki, 1983; Sone et al., 1985). However, genetic analysis of the immune response to those antigens in families or populations revealed that responsiveness is recessive and non-responsiveness to those antigens is a dominant genetic trait that is tightly linked to HLA (Sasazuki et al., 1980a, 1983; Watanabe et al., 1988). This is completely opposite to the situation under the Ir-gene control where responsiveness is dominant and non-responsiveness is recessive. In this paper, we report evidence of how we came across the concept of HLA-linked immune suppression genes (Is-genes) besides Ir-genes, and show evidence for the epistatic interaction between HLA-DR and DQ to determine the immune response to several antigens in humans. [ABSTRACT FROM AUTHOR]

As perhaps the staunchest advocates of repertoire purging as the central mechanism of immunological tolerance, we note with satisfaction a spate of recent, elegant papers which suggest an intrathymic clonal abortion model as the explanation for at least some examples of T-cell tolerance. This view agrees with the classical formulation of the Billingham-Brent-Medawar school of tolerance as a specific, central failure of immune responsiveness. Repertoire purging within the B-lymphocyte compartment remains much more controversial. There is no doubt that experimental models exist where the B cell is the reversible target of tolerance induction. The question is, in view of the ease of inducing autoantibody formation both in vivo and in vitro, just how relevant are such clonal anergy mechanisms to authentic self-tolerance? Arguments are presented that there must be two windows of tolerance susceptibility in the ontogeny of the B cell; one while it is maturing in the bone marrow, to prevent autoreactivity of high affinity to important accessible self-antigens; and a second soon after activation of pre-memory cells by exogenous antigen, to prevent fortuitous mutations towards high-affinity anti-self-reactivity establishing a forbidden clone. [ABSTRACT FROM AUTHOR]

The experiments reported in this paper examine the cell-surface phenotype (CD5, CD4, CD8, TI9, MHC class II and sIg) and cell output of lymphocyte subsets circulating through a subcutaneous lymph node in the sheep fetus, in an environment unaffected by foreign antigen and circulating immunoglobulins. CD4+ lymphocytes were the major T-cell subset in fetal lymph and were clearly enriched in lymph compared with blood, whereas TI9+, CD8+ and B lymphocytes were not. It seems likely that in the fetus CD4+ lymphocytes are extracted from the blood at a faster rate than are other T-cell subsets and B cells. There was a much higher percentage of CD8+ and T null cells and a lower percentage of MHC class II+ and B cells circulating in the fetal lymph than in adult lymph, while the percentage of TI9+ lymphocytes in fetal blood was twice that in the adult. Although the hourly cell output from an adult prescapular lymph node was far higher than that from a fetal lymph node, the circulation of lymphocytes through fetal lymph nodes was much greater per gram lymph node weight than that through adult lymph nodes. The wholesale recirculation in the fetus of all the major T-cell subsets found in the adult is paradoxical because it is not known what function they serve in the fetus in the absence of antigen and ongoing immune responses, although clearly they are not memory cells. [ABSTRACT FROM AUTHOR]

This paper examines the possibility of a functional linkage between class I MHC molecules and the T-cell receptor complex for antigen (T3-Ti). A newly developed anti-CD3 antibody (500A2) was used as an activation signal for EL4 lymphoma cells and allospecific cytotoxic T-cell clones (CTL), and the production of IL-2/IL-2 receptor in EL4 cells and serine esterase in CTL was determined. Anti-CD3 antibody-induced activation of both EL4+ and CTL cells was enhanced in the presence of immunologically cross-linked and immobilized anti-H-2 (class I) antibody reactive against the H-2 haplotype of the responding T cells. A number of H-2-negative and H-2-positive EL4 subclones were generated and tested for anti-CD3 antibody-induced IL-2/IL-2 receptor production. Although both H-2-positive and -negative subclones expressed CD3 antigen and produced IL-2 after activation with the phorbol ester TPA, only the H-2-positive cell clones produced IL-2 and expressed IL-2 receptor after anti-CD3 antibody induction. Our results are compatible with the existence of a functional linkage between the class I and the CD3 molecules on the surface of T cells. [ABSTRACT FROM AUTHOR]

A panel of monoclonal antibodies (mAb) was developed by the fusion of Sp2/0 myeloma cells and spleen cells from mice immunized with peripheral blood mononuclear cells (PMNC) or T cells from NIH swine leucocyte antigen (SLA) inbred miniature swine. Twenty stable hybridoma clones were isolated that secreted mAb that reacted with swine PMNC, as determined by an enzyme-linked immunosorbent assay (ELISA). The binding profile to swine PMNC and the ability to fix complement of these mAb were investigated by flow cytometric analyses. The molecular weights of the antigens recognized by six of the mAb were determined by immunoprecipitation of 125I-surface-labelled PMNC, followed by SDS-PAGE under reducing conditions. The most interesting mAb, 7-34-1 (IgG2a), precipitated a putative MUC class I molecule composed of a 50,000 MW heavy chain and a 12,000 MW light chain (β2m). This is the third SLA class I-reactive monoclonal antibody to be described for swine. Properties of the mAb described in this paper, mAb 7-34-1, are different from the two other SLA class I-specific mAb that have been described elsewhere in the literature (mAb 74-11-10 and mAb FF85). M onoclonal antibody 7-34-1 recognized class I antigens of SLA haplotypes a, c and din an equivalent manner. This mAb should be especially useful as a general anti- SLA class I reagent for experiments on NIH miniature swine. [ABSTRACT FROM AUTHOR]

In different murine systems, delayed-type hypersensitivity (DTH) swelling responses at 24–48 hr after antigen challenge were preceeded by an early 2-hr swelling response. The 24-hr DTH response is thought to depend on this early (DTH-initiating) hypersensitivity response. In this paper we show that in the syngeneic DBA/2-SL2 routine turnout system only an early 2-hr swelling response can be evoked. This early hypersensitivity response was tumour specific and serotonin dependent. The early hypersensitivity response in contact hypersensitivity has been ascribed to antigen-specific T-cell factors. To test whether similar T-cell factors were involved in the early hypersensitivity response in this syngencic turnout system, we have transferred lymph node, spleen lymphocytes and scram from immunized mice into naive recipients. The serum was fractionated in two fractions, a 50,000–80,000 MW fraction, and a 120,000–190,000 MW fraction. In recipients of lymphocytes, total serum and the 50,000–80,000 MW fraction of the serum, an early hypersensitivity response can be evoked. So, these data suggest the involvement of specific T-cell factors in the development of an early hypersensitivity response against syngeneic tumour cells. Despite the development of an early (DTH initiating) hypersensitivity swelling response these immunized animals cannot develop a classical 24-hr swelling response. This absence of the 24-hr response in the presence of the 2-hr response is discussed in relation to the frequently observed immune suppression in tumour-bearing mice. [ABSTRACT FROM AUTHOR]

Reagents for the identification of rabbit cell markers have been developed at a relatively slow rate. In this paper, rabbit cells are being characterized by polyclonal antibodies against a Tall antigen (RTLA), a B-cell antigen (RABELA) and an analogue of murine Ia antigen. A number of monoclonal antibodies, specific for lymphocytes and/or bone marrow and/or polymorphonuclear leucocytes, have been used for the analysis of cells with identifiable membrane antigens. Populations that have cells with two of the above antigens in the membranes were identified. To these ends, complement-mediated cell kill by antisera alone and in mixtures was employed. [ABSTRACT FROM AUTHOR]

In this paper, we describe the activity of conjugates constituted of monoclonal antibodies chemically coupled to ricin and the ricin A-chain-like toxin gelonin. Several antibody-toxin conjugates (immunotoxins) were assayed against a Thy 1.2+ and Lyt 2.2+ T-cell line. Anti-Thy 1.2-gelonin and anti-Lyt 2.2-ricin immunotoxins (IT) had a good cytotoxic activity against target cells, whereas anti-Lyt 2.2-gelonin showed weak or no cytotoxicity. An anti-Lyt 2.2-gelonin IT displayed detectable cytotoxicity only when cells were pretreated with ammonium chloride. IT binding activity was very similar for anti-Thy 1.2 and anti-Lyt 2.2 IT, and surface antigen density was of the same order of magnitude for Thy 1.2 and Lyt 2.2 antigens. Our results suggest that intrinsic properties of the surface target antigen are able to influence the IT cytotoxic efficacy. [ABSTRACT FROM AUTHOR]

There is considerable confusion over whether the antigen-specific T suppressor factors (TsF) described by different authors are indeed equivalent. This paper investigates whether monoclonal TsF3, obtained from hybridomas derived from mice injected subcutaneously with NP derived spleen cells. is functionally equivalent to the conventional T suppresser factor, produced by mice injected intravenously with chemically reactive, water soluble haptene (picrylsulphonic acid and oxazolone thioglycolic acid). Comparison of monoclonal anti-NP TsF3 with conventional anti-picryl and anti-oxazolone T suppressor factor showed that both armed the non-specific T accepter cell (Tacc) which was sensitive to cyclophosphamide and adult thymectomy. Moreover, non-specific inhibitor (nsINH) of the transfer of contact sensitivity was released when antigen, together with major histocompatibility complex products (MHC). reacted with conventional or monoclonal TsF on the surface of the non-specific T accepter cell. The interaction of monoclonal TsF3 with antigen, which led to the release of nsINH, required the presence of MHC and was I-J restricted. However, there was no Igh-1 restriction. The equivalence of conventional anti-picryl and anti-oxazolone TsF has been demonstrated by arming the Tacc with a mixture of these two suppressor factors, and then triggering the release of nsINH with the mixed haptene ‘picryl-oxazolone-lysine’ which crosslinks separate molecules of TsF. A similar equivalence of conventional anti-oxazolone TsF and monoclonal anti-NP TsF3 was demonstrated using the mixed hapten ‘NP-oxazolone-lysine’ to trigger the release of nsINH. It was concluded that monoclonal TsF3 and conventional TsF were equivalent, and that both had an indirect mode of action through the non-specific T acceptor cell which led to the production of non-specific inhibitor. [ABSTRACT FROM AUTHOR]

CBA/N mice harbour an X-linked B cell defect which is transmitted by CBA/N female mice to their hybrid male progeny. These mice mount normal responses to thymus-dependent (TD) and some thymus-independent (TI-1) antigens, while the response to TI-2 antigens is absent. Hapten-specific plaque-forming cell (PFC) responses to TD antigens can be blockaded by concomitant exposure of these mice to TI-2 antigens bearing the same hapten. This paper investigates in defective mice the blockade of their response to TNP3-LPS (trinitrophenylated lipopolysaccharide, a TI-1 antigen), imposed by DNP59-Ficoll (dinitrophenylated Ficoll, a TI-2 antigen). The effectiveness of the blocking agent, DNP59-Ficoll, differed in various inbred mouse strains: CBA/N × C3H/HeN F1 male > CBA/N female > CBA/N · C3H/HeN F1 female. The role of T cells in the observed hapten-specific blockade phenomenon was investigated using athymic CBA/N nude mice and a B cell tolerogen. Our findings indicate that T cell participation is not essential for the blockade of CBA/N PFC responses and they suggest that direct blockade of TI- and TD-responsive B cell populations is likely to occur. [ABSTRACT FROM AUTHOR]

The results presented in this paper demonstrate that a mouse IgM monoclonal antibody (T-80) recognizes an antigen on cells of the T-lymphocyte lineage of sheep. However, this antibody does not identify all T cells, as 10-20% of thymocytes and some peripheral-blood T cells are negative. T-80- thymocytes reside in the medulla. The majority of cortical thymocytes are T-80+ and classified as dull cells on the basis of antigen density per cell as measured by flow microfluorometry. In contrast, T-80+ cells in the periphery can be categorized into two populations, i.e., dull cells and bright cells. Suggestive evidence was obtained that bright T-80+ cells are fast recirculating T cells, whereas dull ceils are sessile or less easily mobilizable T cells in the periphery. In foetal environment, over 90% of thymocytes and approximately 5% of spleen cells are T-80+ at 54 days of gestation (gestation period = 150 days), which may indicate that T-cell emigration from the thymus commences well before mid-gestation in sheep. [ABSTRACT FROM AUTHOR]

One of the T suppressor circuits induced by picrylsulphonic acid includes the T suppressor cell (Ts-eff) which acts at the efferent stage of the contact sensitivity reaction and produces antigen-specific T suppressor factor (TsF). This factor does not act directly but arms a T acceptor cell (Tacc). This Tacc liberates a non-specific inhibitor when it is armed with TsF and then exposed to picrylated cells sharing the I-J genotype of the source of the TsF. This paper investigates the role of I-J region gene products in this T suppressor circuit. Two approaches were used. Syngeneic CBA (H-2k) lymphocytes were separated into I-J+ and I-J- cells by treatment with anti-I-Jk serum followed by panning on anti-immunoglobulin plates. The cells were then picrylated and used as a source of antigen. Alternatively, B10.A congeneic mice syngeneic (SR) or allogeneic (3R) with CBA at the I-J locus were picrylated and used similarly. The main findings were as follows. (i) The intravenous injection of picrylated I-J+ spleen cells but not a similar number of I-J- cells induced Ts-eff which blocked the transfer of contact sensitivity. Picrylated unseparated cells syngeneic, but not allogeneic, at the I-J locus were also effective. (ii) It is known that the lymphocytes of mice injected with picrylsulphonic acid and then re-exposed to antigen by painting with picryl chloride liberate TsF in vitro. The re-exposure to antigen can be replaced by the intravenous injection of picrylated I-J+ cells or by cells syngeneic at the I-J locus the day before harvesting the spleen cells. (iii) The release of non-specific inhibitor by Tacc armed with TsF requires exposure to picrylated I-J+ cells or cells syngeneic at the I-J locus. The requirement for antigen on a cell bearing syngeneic I-J suggests that antigen together with I-J is an activation signal in this T-cell circuit. The simplest explanation is that the receptor of the pristine Ts and of the mature Ts-eff is similar to T suppressor factor. [ABSTRACT FROM AUTHOR]

This paper investigates desensitization in vitro, e.g. the inhibition of the transfer of contact sensitivity to picryl chloride by incubation of the passive transfer population with picrylated spleen cells. It asks whether desensitization is based on the same T-suppressor circuit which is responsible for the inhibition of passive transfer by antigen-specific T-suppressor factor (TsF). In this circuit, the T-suppressor cell which acts at the efferent stage (Ts-eff) makes TsF. This TsF depresses contact sensitivity indirectly by arming a T-acceptor cell (Tacc). The armed Tacc, when exposed to antigen (picrylated spleen cells), liberates a non-specific inhibitor which blocks the transfer of contact sensitivity. The three elements of this T-suppressor circuit occur in nylon wool-purified T cells prepared from the lymph nodes and spleens of mice four days after immunization with picryl chloride. This population transfers contact sensitivity and can be desensitized in vitro. It contains Ts-eff which can be isolated by panning (adherence) on picrylated albumin and detected by their ability to inhibit passive transfer. The 24 hr supernatant of cultures of these cells contains TsF. Finally the population contains Tacc which appear in the spleen 2 days after immunization and virtually disappear by 10 days. Further experiments demonstrated that the Ts-eff and the Tacc were not merely present but actually required for desensitization in vitro. Immune cells depleted of both Ts-eff (by panning on picrylated albumin) and Tacc (by arming with anti-oxazolone TsF and panning on oxazolonated albumin) cannot be desensitized. To restore desensitization both Ts-eff and Tacc must be added back. The Ts-eff were characterized as cyclophosphamide resistant, adult thymectomy sensitive cells (Cyr, ATx5), which adhered to antigen and were produced only by specific immunization. The Tacc were characterized as CF5, ATx5 cells which adhered to antigen only after arming with antigen-specific T-suppressor factor and were produced after immunization with an unrelated contact sensitizer, 'oxazolone'. It was concluded that desensitization in vitro was due to the interaction of two distinct T cells: the T-suppressor cell which acts at the efferent stage of the contact sensitivity reaction and the T-acceptor cell which becomes armed with the specific T-suppressor factor produced by the Ts-eff. [ABSTRACT FROM AUTHOR]

In this paper we describe the first in vitro response to the liver alloantigen F. The anti-F response serves as a valuable model for autoimmune phenomena since priming appropriate strains of mice (responders) with allogeneic but not syngeneic type F leads to autoantibody production. The in vitro system is based on the proliferation of T cells, from mice primed in vivo with F, when coincubated with splenic adherent cells (SAC) prepulsed with F in vivo. The system displays two important correlates of the in vivo antibody response to F:1.T cells from mice primed with syngeneic F do not proliferate when incubated with SAC prepulsed with syngeneic F and 2. Mice that do not make antibody responses to allo F in vivo (DBA/2) do not show in vitro proliferative responses. These findings indicate that the proliferative assay is a good in vitro model for the F response. [ABSTRACT FROM AUTHOR]

In the present paper it is shown that the non-species specific determinant of the antigenic thymus-brain system previously detected in murine and human brain also exists in human thymus. However, in contrast to the situation in mice and rats this antigenic structure is not expressed on suspended thymic lymphocytes, but is associated with thymic tissue largely depleted of thymic lymphocytes. Moreover, this determinant is also detectable in human lymph nodes. Besides the non-species-specific antigenic determinant human thymus and brain also share a species-specific determinant. In contrast to the non species specific determinant this structure is also displayed by suspended thymic lymphocytes, certain peripheral blood lymphocytes and bone marrow cells. The non-species-specific determinant detected in human thymus is borne by a structure, which physico-chemically resembles the thymus-brain antigen isolated from murine brain and thymus as well as from human brain. Although the structure bearing the species specific antigenic determinant has a similar apparent molecular weight both antigens could be separated by ion exchange chromatography indicating their molecular diversity. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to investigate whether an antibody directed against the exocrine secretion, saliva, is able to induce a modification in vivo within the specific cells of the submaxillary glands which synthesize this secretion. The salivary antigens synthesized within the glandular acinar cells are secreted into they respective lumen and are not present in the general circulation or in the intercellular spaces of the gland. When heterologous anti-saliva antibodies are injected into mice, they induce marked lesions within the acinar cells of the submaxillary glands. When different antibodies recognizing different salivary components are injected, they ail induce similar modifications; it is not yet possible to distinguish whether different cells are involved in the synthesis of the different salivary components. The lesions described seem specific since other organs studied, such as the pancreas and the stomach, are unaffected. The different possible mechanisms of this cytotoxic effect are discussed. [ABSTRACT FROM AUTHOR]

For most antisera a linear relationship can be shown between log antigen concentration and the log concentration of antibody required to bind half the available antigen. This paper shows that the slope of this line, s, is related to the distribution of individual antibody clonotypes of different affinity. It is argued that the general form of the distribution approximates to exponential (rather than for example Gaussian) and that this indicates a requirement for some force to be exerted through the antigen-receptor bond in order to activate a B cell. An alternative parameter, A, which gives more weight to high affinity clonotypes, is offered in place of K0 as a measure of the avidity and biological effectiveness of an antiserum. [ABSTRACT FROM AUTHOR]

A mean of 6.9 per cent of small lymphocytes in peripheral blood preparations and between 1.8 and 2.4 per cent of small lymphocytes in lymph node, spleen, bone marrow and thymus preparations from unimmunized guinea-pigs bound 125I-labelled purified protein derivative of mammalian tuberculin (mammalian PPD). The percentage of these cells fluctuated but did not alter substantially after immunization with BCG or with BCG emulsified with human thyroglobulin (HTg) in Freund's incomplete adjuvant (FIA). Blocking experiments indicated that the binding of 125I-labelled mammalian PPD was specific and there was tentative evidence that the lymphocyte receptors may be IgG. A comparison is drawn between the observed time course of 125I-labelled mammalian PPD- binding small lymphocytes and the response of lymphocytes sensitive to strong histocompatibility antigens, and it is proposed that the propensity of certain anti- gens to induce a delayed hypersensitivity-type response is related to the presence of substantial numbers of antigen-binding cells in unimmunized animals. A noteworthy incidental finding was an unexplained depression in the cellular and humoral responses to mammalian PPD in guinea-pigs that had been immunized with HTg-BCG-FIA emulsion. [ABSTRACT FROM AUTHOR]

Mice infected with African trypanosomes produce exceptionally large amounts of serum IgM, a major part of which binds to non-trypanosome antigens such as trinitrophenol and single-strand DNA. In this paper, we describe that in cattle infected with Trypanosoma congolense and T. vivax, similar antibodies are found, although they bind mainly to protein antigens, such as β-galactosidase, ovalbumin and ferritin. The parasite non-specific IgM antibodies appear around the same time as the parasite-specific antibodies, but their origin and function are not clear. We tested the hypothesis that CD5+ B cells (or B-1 cells), which increase during trypanosome infections in cattle, are responsible for production of antibodies to non-trypanosome antigens. Splenic CD5+ and CD5- B cells from infected cattle were sorted and tested in a single cell blot assay. The numbers of immunoglobulin-secreting cells were similar in both B-cell populations. However, antibodies with reactivity for non-trypanosome antigens were significantly more prevalent in the CD5+ B-cell fraction and were exclusively IgM. The preference for production of these antibodies by CD5+ B cells and the expansion of this subpopulation during infections in cattle, strongly suggest that CD5+ B cells are the main source of trypanosome non-specific antibodies. We propose that these antibodies are natural, polyreactive antibodies that are predominantly secreted by CD5+ B cells. Since B-1 cells are up-regulated in many states of immune insufficiency, the immunosuppression associated with trypanosome infections may be responsible for the increase of this subset and the concomitant increase in trypanosome non-specific antibodies. [ABSTRACT FROM AUTHOR]

Peripheral lung tissue contains large numbers of T cells, strategically located for immune surveillance at the blood-air interface. Given the intensity of antigenic exposure at this site, it is clear that local T-cell activation events require strict control, in order to maintain tissue homeostasis. How this control is achieved in this unique tissue microenvironment is unknown, and the present study sought to elucidate the process via detailed analysis of the surface phenotypic characteristics of freshly isolated lung T cells. We report below that these cells display typical characteristic of ‘postactivation’, notably elevated basal Ca2+ concentrations, down-modulated T-cell receptors, expression of Ia and ‘late’ activation antigens and concomitant CD4/CD8. However, levels of interleukin-2 receptor and CD2 expression were below those expected of ‘activated’ T-cell populations, and virtually all of the cells were found to be in the G0/G1 phases of the cell cycle. These properties bear a remarkable similarity to those of T cells activated in the presence of endogenous tissue (alveolar) macrophages from the lung (see accompanying paper). We hypothesize that they reflect the in vivo operation of an endogenous macrophage-mediated T-cell anergy-induction process, the function of which is to limit the local clonal expansion of T cells in peripheral lung tissue after in situ activation. [ABSTRACT FROM AUTHOR]

In this paper we report partial amino acid sequence for Clq receptor (ClqR). The N-terminal amino acid sequence of isolated ClqR and the sequences of peptides obtained by V8/trypsin digestion show a high degree of similarity to the cDNA-derived amino acid sequence of a human protein which was initial reported as a component of RoSSA and subsequently as calreticulin. This sequence in turn shows homology with Onchocerca volvulus antigen (RAL-1) and B50 murine melanoma antigen. A component of approximately 53,000 MW, isolated from human spleen, was found to have identical mobility on SDS-PAGE to ClqR and identical N-terminal sequence, but a different overall charge. Human antibodies from Sjögren's syndrome patients did not recognize ClqR, but showed positive reaction with the purified 53,000 MW component from spleen. Rabbit antibodies against denatured ClqR, in contrast, recognized both ClqR and the purified 53,000 MW component. The 53,000 MW spleen component thus has an identical N-terminal sequence to calreticulin, and to the reported RoSSA component, and is recognized by antibodies in Sjögren's syndrome sera. The data obtained indicate that ClqR and the reported calreticulin/RoSSA component are similar but not identical molecules, which belong to the same protein superfamily. [ABSTRACT FROM AUTHOR]

Evidence from in vitro studies indicates that immunoglobulin A (IgA) responses are highly T dependent, yet investigations of the requirement for cognate help For IgA responses in tiro have not previously been undertaken. Experiments reported in this paper employ hapten-carrier immunization of individual Peyer's patches (PP), the site of generation of IgA antibody-containing cells (ACC) responding to lumenal antigenic challenge in the intestine, to determine the requirements for T-cell and B-cell priming under normal physiological conditions in vivo. These experiments demonstrate that both hapten-specific B-cell priming and carrier-specific T-cell priming in PP are required for an IgA-specific anti-hapten ACC response in the intestinal lamina propria to subsequent lumenal challenge with hapten-carrier conjugate. These results confirm that IgA B-cell induction in PP requires cognate T-cell help. An IgA ACC response can also be obtained when hapten and carrier priming occur in different PP, providing functional significance for our previous observations that PP-derived T-helper cells are able to migrate between PP after priming. [ABSTRACT FROM AUTHOR]

Whilst the ability of isoantibodies to agglutinate mouse red cells in saline medium does depend in part upon the properties of the antibody molecules, the concentration of antigen upon the red cell and certain genetically determined properties of the cell surface are of even greater importance. The red cells of mice of any strain will give positive results in the human serum:dextran system whilst reactions in a saline medium are unusual. In this paper the term ‘incomplete antibody’ is used to denote antibodies that can only be detected in conjunction with other antibodies in the human serum:dextran system. The time of appearance of antibodies to homografts of an ascites sarcoma, an ascites leukosis and a solid mammary carcinoma has been studied. Incomplete antibody as defined above has been detected by two methods. In the blocking test incomplete antibody is allowed to react with red cells before contact with complete antibody, a positive result being observed as a fall in titre when the treated red cells are subsequently exposed to complete antibody. In the second type of test, the synergic test, incomplete antibody is mixed with suitably diluted complete antibody and fitrated against suitable red cells, a positive result being a significant rise in titre as compared with complete antibody mixed with normal serum. Antibodies produced by the antigen donors did not give significant blocking or synergic effects. Incomplete antibodies are sometimes detectible on the third day and with regularity on the fourth day. Antibodies ‘complete’ for A strain red cells may appear at any time from the fifth day onwards. There is sometimes a drop in fitre of varying duration on the sixth day. This corresponds with the commencement of marked inflammatory changes on the graft bed. The maximum titre is attained at about two weeks. Antibodies may disappear in under three months or persist as long as a year. The function of antibodies in homograft reactions varies with the target tissue. However, they appear before the onset of anatomical signs of homograff response regardless of the type of target cell. [ABSTRACT FROM AUTHOR]

The experiments described in this paper extend the observations of previous work in vitro demonstrating a decrease in the frequency of antigenreactive units specific for horse RBC in spleen cells from mice primed with KLH. It was observed that the addition of lymphoid cells having T-cell function reconstituted the anti-HRBC response to normal values. Significant enhancement of the response beyond the normal values could be evoked using two dissimilar methods, (i) addition of allogeneic thymus cells, and (ii) restimulation in vitro with the priming antigen. The latter type enhancement was elicited by the addition of small doses of KLH to cultures of spleen cells from mice recently primed with KLH, including cultures otherwise demonstrating antigen-induced suppression. The stimulus required to enhance the response to HRBC in these cultures was specific for the priming antigen, KLH. These results are discussed in the light of current theories of 'antigenic competition' and specific heterologous enhancement. [ABSTRACT FROM AUTHOR]

Rabbit kidney tissue contains antigens which are tissue-specific and species restricted, as well as other antigens which are shared by different organs of the animal. The stability of these antigens was investigated as a function of temperature, in order to explore the possibility of thermal fractionation. It was observed that one rabbit kidney-specific autoantigen was destroyed at 56° and another at 65°. A third antigen, which is restricted to the rabbit species but is non-tissue specific, was destroyed at 72°. Ultracentrifugal analysis of the saline extract at different concentrations showed the presence of several components, whose extrapolated values at zero concentration were found to be 4.2S, 6.2S, 10S, 19S, and 80S. The first two components were the most prominent. The rabbit kidney-specific autoantigens were fractionated by a first step of salting out with ammonium sulphate at 4°. The fraction that precipitated in the range from 2.00 to 3.00 M retained most of the antigenic activity. As this fraction was quite impure, it was chromatographed through DEAE-cellulose, then processed through gel filtration columns, using Sephadex G-100 and G-200, and finally purified in agar zone electrophoresis. Two antigens were isolated and both shared similar antigenic characteristics. However, they had slight differences regarding their physicochemical properties. Sedimentation coefficients of 4.6S and 4.8S were obtained for them. Both antigens possessed a slow electrophoretic mobility, similar to that of the β-globulins. The antigen with higher sedimentation value was slightly faster electrophoretically than the other. [ABSTRACT FROM AUTHOR]

The purpose of this study was to demonstrate the presence of exoantigens in the intestinal washes of mice infected with H. nana, to partially purify the antigen, and to show identity with heterologous antisera to H. nana soluble proteins. This paper describes the increase in specific activity to tapeworm exoantigens with increased purification both with serum obtained from infected mice and heterologous rabbit serum. [ABSTRACT FROM AUTHOR]

This paper describes the ultrastructural location of labelled antigens and carbon in the spleens of rats from 4 minutes to 5 days after injection. Particular attention was focused on the sites of deposition 4 minutes after intra-arterial injection of microgram quantities of 125I-labelled Salmonella flagellar antigens, crayfish haemocyanin and BSA, using colloidal carbon for comparison. The combination of radioautography with both light and electron microscopy showed the importance of antigen binding by lymphocytes in the marginal zone of the spleen. Macrophage sequestration of antigens was not prominent in the spleen, although it occurred in the liver with the flagellar antigens and haemocyanin. In the spleen marginal zone, avid antigen-binding cells were found in situ 4 minutes after the injection of labelled haemocyanin. These appear to be the counterpart in vivo of antigen-binding lymphocytes prepared in vitro. Such cells also occurred infrequently after the injection of labelled polymerized flagellin, but were not found with either BSA or carbon. The apparent movement of flagellar antigen from the marginal zone to the white pulp between 1 and 2 hours after injection was seen to involve lymphocyte-associated antigen. The follicular antigen localization occurring from 1 day onwards after injection was on the dendritic reticular cells of germinal centres, as has been described in lymph nodes after subcutaneous injection. Carbon particles were rapidly sequestered in macrophages of the spleen and liver, although some particles were found between cells in the marginal zone for as long as 2 hours after injection. By 2 and 5 days, however, all the carbon was in phagocytes, even in the white pulp. Differences between the localization of antigens and carbon were clear, even in the ultrastructural sites of their location in tingible body macrophages of germinal centres. The unexpected emphasis of lymphocyte association with labelled antigens in the spleen marginal zone has allowed a revision of the mechanism previously proposed for the movement of antigens within the microenvironments of the spleen. [ABSTRACT FROM AUTHOR]

This paper describes a new method for the morphological study of individual antibody-forming cells (AFC) on cell smears of the quality of normal haematological preparations. The early AFC response to polymerized flagellin of S. adelaide was studied in vivo using C57BL mice, which have very low background levels of AFC and in vitro using dispersed spleen cell cultures from CBA mice. AFC, arising as a result of in vivo or in vitro stimulation were found to comprise a heterogeneous population, including basophilic mononuclear cells, lymphocytes of most sizes, immature blast cells and occasional plasma cells. The earliest AFC detected comprised a high percentage (28 per cent in vivo, 31 per cent in vitro) of small lymphocyte-like cells. Studies of the incorporation of [³H]thymidine showed that most AFC arose by proliferation but that a proportion of AFC, the small lymphocyte-like cells, arose by differentiation of precursor cells not involving cell division. The effects of antigen concentration on the kinetics of AFC were investigated in vitro. Subtolerogenic antigen doses caused a delayed and decreased AFC response. [ABSTRACT FROM AUTHOR]

Data presented in this paper indicate that by column chromatography using an O acetylated galactan, a considerable degree of purification of specific antibody to O antigen 5 may be achieved. [ABSTRACT FROM AUTHOR]

When lymphoid cells from hypersensitive rabbits are incubated with antigen, biologically active substances are formed and released which are capable of inhibiting the migration of normal non-sensitized mesenchymal cells. In the present paper some basic parameters of their production were determined. These substances were regularly obtained after 6 and 18 hours incubation, but not after 2 hours. Under more favourable cultivation conditions (lower density of lymphocyte suspension) an increased activity in the cell extracts as compared with the supernatants was observed. Another critical factor in the production of these substances is the quantity of antigen added. Ten micrograms of PPD leads to the production and liberation of a highly effective substance. A lower dose of antigen results in the liberation of a substance into the supernatant which by itself is almost inactive, but becomes more active when more antigen is added. The efficiency of the released substances was determined by serial dilution. The inhibiting activity was maintained at 1:5 and 1:20 and sometimes at 1:100 dilutions. [ABSTRACT FROM AUTHOR]

The studies reported here indicate that tanned red cells coated with a mixture of chromatographically purified ovalbumin and conalbumin give agglutination titres which are directly related to the amount of antibody (as meas- ured by quantitative precipitation) present against either of these antigens in mixed sera. With whole (unabsorbed) mixed sera, these coated cells record the titre of the major antibody present, whether this is anti-ovalbumin or anti-conalbumin. There was no evidence of greater sensitivity to anti-conalbumin. A trace of ovalbumin in a preparation of conalbumin used to coat cells is fully sufficient to enable them to react with any anti-ovalbumin in a serum. Twice recrystallized ovalbumin still contains some conalbumin. Sera raised against it may contain unexpectedly high levels of anti-conalbumin and this could cause confusion in tanned red cell tests. [ABSTRACT FROM AUTHOR]

Although induced immunological tolerance of histocompatibility antigens is generally considered to be specific, cases of concomitant third-party unresponsiveness may occur. The present paper describes one case in point. Antigenic overlap between original and third-party donor, as well as runt disease have been excluded as possible explanations for the observed lack of specificity. It is hypothesized that an innate inability, of the host to respond to the relevant third-party antigen(s), or the ability of certain antigens to induce tolerance of themselves as well as of distinct but related antigens, may be responsible for the phenomenon. [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.

Lists articles to be published in the 'Immunology' periodical. Role of antigen presenting cells and interleukin-12 in the priming of antigen specific CD4[sup +] cells by immune stimulating complexes; Cell activation by monosaccharide lipid A analogs utilizing Toll-like receptor 4; Cytokine synthesis.

The thennoinactivation kinetics of IgE were studied in experimental models revealing the antigenic properties and the basophil-sensitizing capacity of these immunoglobulins. A pool of human sera containing anti-Dactylis gloinerata (Dg) IgE was heated from 5 mm up to 4 hr at 56°. The IgE antigenicity was tested by two polyclonal 125I-labelled anti-IgE antibodies; one anti-IgE was specific of the whole Fc∊ region, while the other had a specificity restricted to the D∊2 domain. Radioimmunoassays showed that the D∊2 epitopes were more rapidly altered than the D∊1 epitopes. The capacity of IgE to bind to basophil Fc∊ receptors was assayed by passive sensitization experiments. Basophil sensitivity towards the Dg pollen extract was tested by histamine release experiments in the presence of this allergen. A progressive decrease in cell sensitivity was observed when IgE samples used for cell sensitization were heated for longer than 5 mm. Thermoinactivation kinetics of IgE revealed an unexpected increase in the apparent quantity and biological activity of IgE heated for 5 mm at 56°. This fact could be due to auto-anti-IgE antibodies linked to the unheated IgE and which interfere with the biological activities of lgE and their quantification. [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 effects of cyclophosphamide (CY), thymectomy and splenectomy on the antigenic competition in contact hypersensitivity between dinitrofluorobenzene (DNFB) and picryl chloride (PCI) was investigated. Contact sensitivity to PCI was suppressed by a prior painting of DNFB. When these two sensitizers were painted 7 days apart and CY was injected 3 days after the painting of DNFB, the antigenic competition did not occur. On the other hand, when CY was injected 3 days before painting of DNFB, the antigenic competition was partially abolished. The antigenic competition was seen in mice 2 weeks after adult thymectomy and in splenectomized mice. However, antigenic competition did not occur in mice 6 weeks after thymectomy. These results suggest that some thymus-derived cells may be involved in the antigenic competition in contact sensitivity. [ABSTRACT FROM AUTHOR]