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The role of the spleen in humoral antibody formation and in the pathogenesis of immune thyroiditis was studied by splenectomizing four monkeys (Macaca mulatta) prior to thyroid isoimmunization. Splenectomized animals, as well as intact controls, were subjected to sequential immunizations and the course of the immune disease was followed by periodic thyroid biopsies and frequent humoral antibody measurements over a period exceeding 1 yr. Extirpation of the secondary lymphoid organ markedly inhibited agglutinating antibody response, prevented formation of complement-fixing antibodies, but had no effect on thyrocytotoxic antibodies. In animals subjected to immunization in complete adjuvant a trend towards a decrease in serum complement levels was evident at the terminal stages of the experiments. Despite the inhibitory effects on some immunological parameters, splenectomy in monkeys prior to thyroid isoimmunization did not interfere with the initiation and progression of pathological processes in the thyroid. Indeed in all splenectomized animals immunized with thyroid plus complete adjuvant, fibrotic thyroid lesions (4+) with virtual obliteration of thyroid follicles were evident, in some as early as 120 days after primary immunization; in contrast, non-fibrotic and less severe lesions were noted in the intact animal despite being repeatedly subjected to similar immunization procedures over a period of 340 days. Immunization in the absence of complete adjuvant did not induce thyroid lesions in the presence or absence of spleen. In all animals with severe thyroid lesions, thyroid function decreased as revealed by T4 and 131I-T3 resin uptake measurements. Paper electrophoresis of serum specimens from a monkey subjected to thyroid isoimmunization in complete adjuvant (and after equilibration with 125I-T4) showed a pronounced retention of 125I-T4 radioactivity at the gamma globulin region indicating formation of antibodies to thyroxine. On the other hand, in sera with a low thyroid antibody titre as in splenectomized monkeys or in those animals immunized within complete adjuvant, T4-binding antibodies were not evident. It is concluded that removal of the spleen prior to thyroid isoimmunization in monkeys, rather than inhibiting the severity of the disease may even aid and abet immunopathogenic events destructive to the thyroid. [ABSTRACT FROM AUTHOR]

Two liver-specific antigens are known: a water soluble protein (LP-2) and a water insoluble macromolecular low density lipoprotein (LP-1). In this paper the relative role of the two antigens in the development of experimental immune hepatitis has been investigated. Immunization of rabbits with a human preparation containing both antigens, led in all animals to lesions characteristic of an immune hepatitis. Immunization of the animals with a purified water soluble liver protein proved less efficient: only two out of six animals developed characteristic lesions which were less severe than those in the first group. It was deduced that although not a prerequisite, the liver-specific lipoprotein plays an important supportive role in the development of immune hepatitis, [ABSTRACT FROM AUTHOR]

In a previous paper it had been shown that up to 40% of human peripheral lymphocytes will make rosettes with sheep red cells. In this study the inhibitory effect of antilymphocyte serum (ALS) and of certain other preparations on this rosette phenomenon is described. ALS was prepared in horses by injection of human peripheral lymphocytes and rosette-inhibiting, cytotoxic and agglutinating titres were determined during immunization. The ALS had been tested in vivo by regional administration to vervet monkeys bearing skin allografts. It was found t h a t the peak of rosette-inhibiting titre appeared to provide a good index of immunosuppressive activity. These peaks, and the accompanying periods of immunosuppressive activity, were of short duration, in contrast to the levels of cytotoxic and agglutinathig titres. Antihuman lymphocyte sera had considerable rosette-inhibiting titres against the lymphocytes of the baboon (Papio papio) but little against those of the vervet monkey (Cercopithecus aethiops). Inhibition by ALS of the phenomenon described by us is unaffected by complement. Antihuman globulin serum and phytohaemagglutinin had no inhibitory effect. Digestion of ALS with pepsin to obtain the F (ab')2 fragment had only a slight effect on rosette-inhibiting titres, while it reduced the cytotoxic activity very considerably. The phenomenon described by us is probably different from that reported by other workers, in which only a small proportion of lymphocytes form rosettes. [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]

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]

This paper describes a form of red cell lysis differentiated from classical complement haemolysis by its occurrence in the absence of antibody on the cells and in the presence of EDTA. This type of haemolysis has been called reactive haemolysis. It is the result of the interaction, in the presence of red cells, of at least two serum factors called ‘reactor’ and ‘indicator’, respectively. Reactor only becomes active after incubation at 37° of serum with certain agents, notably antibody-coated bacteria, zymosan and agarose, in conditions similar to those required for complement activation. The potential for the formation of activated reactor could be demonstrated infrequently in healthy subjects but more frequently in sera from hospital patients. Activated reactor behaved as a protein sedimenting between 7S and 19S, and of α2-β1, electrophoretic mobility in agar. Indicator factors were present in all human sera studied, as well as in the sera of a number of mammalian species. They were demonstrable at high dilutions of the serum and required no prior activation for their action. They occurred maximally in the 7S fractions of serum proteins and migrated in the β2 position on electrophoresis. Reactive haemolysis was first observed and can most conveniently lie demonstrated in a red cell-agarose gel. It can also be demonstrated in the test tube following partial purification of activated reactor and indicator factors. Studies in the test tube indicated that a .soluble labile lytic factor was responsible for this type of haemolysis, [ABSTRACT FROM AUTHOR]

Rat liver microsomes were separated into three subfractions by means of ultracentrifugation through sucrose media of different densities and in the presence of different cations. Detergent extracts of these preparations were analysed by double diffusion in agar gel and immunoelectrophoresis with rabbit antisera against each of the subfractions. One subfraction was derived from the ‘rough’ and another from the ‘smooth’ part of the endoplasmic reticulum of the liver parenchymal cells. Their extracts contained at least thirteen soluble antigens in common. However, fraction-specific antigens were also present. Thus, the extracts of the rough (R) membranes contained at least one typical antigen, not found in any of the other fractions. An antiserum against this component also precipitated a non-migrating antigen present only in the extracts of smooth (Sa) membranes. These two antigens may represent different molecular forms of a substance involved in binding of the ribosomes or in the assembly of membrane subunits. At least eleven of the antigens common for the two fractions exhibited enzymatic activities when assayed after precipitation with antibody in the immunoelectro- phoretic plates. Six immunologically and electrophoretically distinct antigens had esterase activity with α-naphthyl propionate as substrate. Two of these esterases also split indoxyl acetate. Three other antigens with acid phosphatase activity split both α-naphthyl acid phosphate and β-glycerophosphate. Three antigens had nucleoside diphosphatase activity when tested with uridine- or inosine-diphosphate. Preliminary experiments also suggested that two additional antigens possessed NADH-diaphorase activity and thus could belong to the microsomal electron trans- port systems. The third subfraction consisted of electron-microscopically smooth membranes (Sb), enzymatically different from those of the endoplasmic reticulum. The antigens typical for the latter were either absent or present only in minor and variable concentrations. Its extracts contained at least two typical antigens. One of these was identified as contaminating ferritin. The nature and origin of the other antigen has not yet been established. All antigens described in this paper were immunologically different from the common rat serum proteins. [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]

This paper describes the course of infection and development of immunity in guinea-pigs after intradermal inoculation of Leishmania enriettii, and the use of in vivo and in vitro techniques to characterize the immunological response to infection and artificial immunization. Inoculation of 106 amastigotes into the ear produced a nodule which ulcerated in 2-3 weeks and healed in 8-16 weeks. 8% of animals developed cutaneous metastases which healed with the original lesions. Histology of the primary lesions showed epidermal necrosis overlying a mass of parasitized macrophages which, after 4-6 weeks, became surrounded and infiltrated by lymphocytes. Histological changes in the draining lymph node began after 3 days and proceeded for 6 weeks; both germinal centres and paracortical areas were hyperplastic and the medulla contained many plasma cells. Superinfection produced an 'isophasic" lesion, but reinfection after healing elicited only a delayed hypersensitivity response. Artificial immunization with soluble and insoluble antigenic extracts of L. enriettii in Freund's complete adjuvant partially protected against infection; extracts of other leishmanial species Jailed to protect. Immunological paralysis, attempted with intravenous injections of soluble antigen, increased the severity of subsequent infection. Both infection and immunization were accompanied by delayed hypersensitivity which could be transferred passively by lymphoid cells. Cell-mediated immunity was studied in vitro by the ability of soluble leishmanial antigens to transform lymphokine, to inhibit macrophage migration, and to induce the production of lymphokine factors from lymphocytes of sensitized animals. A target cell system was devised in which sensitized lymphocytes destroyed monolayers of parasitized macrophages. Cross reactivity of leishmanial with mycobacterial antigens was shown in skin tests and in target cell destruction, but not in cell transfer or in the other cell culture systems, The phagocytic activity of peritoneal macrophages from recovered animals was increased for homologous but not for heterologous species of Leislumania; the growth of ingested organisms was not however reduced. Circulating antibodies were not demonstrated by passive cutaneous anaphylaxis, or by agglutination of antigen coated sheep erythrocytes, in the sera of infected or convalescent animals, although some convalescent animals showed active cutaneous anaphylaxis. However, antibodies were demonstrated by both these techniques in immunized animals, which also showed anaphylactic and Arthus hypersensitivity when skin tested with. the soluble antigens. The results are taken to indicate that cellular mechanisms are prominent in the development of immunity of the guinea-pig against L. enriettii, and ways in which the host may eliminate the parasite are discussed. It is concluded that this model provides an experimental counterpart of human cutaneous leishmaniasis and that it is suitable for the analysis of the role of cell-mediated specific immunity in resistance to intracellular infection. [ABSTRACT FROM AUTHOR]