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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]

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]

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]

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]

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]

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]