Search

Phytohaemagglutinin transformation of normal lymphocytes was significantly inhibited by the plasma and by extracts of lymphocytes in six out of eight cases of untreated chronic lymphatic Ieukaemia compared with similar material from matched control patients. Since the concentration of inhibitor in lymphocytes was much greater than that in plasma and both inhibitors were thermolabile, it is possible that the plasma inhibitor may be produced by the leukaemic cells. These findings indicate modifications of normal T-ceIl function by constituents of neoplastic lymphocytes but the effect may be due to exaggeration of a normal mechanism in which the surface properties of T cells are modified by products of B cells. [ABSTRACT FROM AUTHOR]

A 3-year-old girl with three severe attacks of extensive skin ulceration and high fever was found to have a defective T-lymphocyte function. In each attack there was a dramatic but temporary recovery following blood transfusion. This was associated with a reversion of skin allergy and restoration of T-lymphocyte function as measured by phytohaemagglutinin (PHA) transformation and sheep red cell rosettes (SRCR). Each remission lasted 2 months. Studies over a period of 2 months after the third transfusion revealed a progressive loss of T-lymphocyte function. The patient was finally injected with a dialysable leucocyte extract. She remained in good health and a rapid normalization of her lymphocyte responses in vitro was observed after the injection. The patient has now been symptom-free for 9 months and has required three injections of leucocyte extract. Each injection has markedly improved her T-lymphocyte function. [ABSTRACT FROM AUTHOR]

The distribution pattern of immunoglobulin- or complement-bearing lymphocytes in healthy controls and in patients with contact dermatitis and with atopic dermatitis has been investigated. A significant predominance of IgD- and C3-bearing lymphocytes was found in ten patients with contact dermatitis. In atopic dermatitis patients the number of IgE- and to a lesser extent of C3-bearing lymphocytes was increased. The results indicate induction or stimulation of two distinct classes of immunologically competent lymphoid cell lines, one in contact and the other in atopic dermatitis. The increased number of B-cells in dermatitis indicates a decreased T-cell population and suggests a deficiency or disturbance of the recirculation of this population. Immunofluorescence staining can be very useful to detect immunoglobulin (Ig) on the surface of living lymphoid cells. Little has been reported on the occurrence of these cells in human skin (Ueki, 1967; Baart de la Faille­Kuyper, 1969; Lai a Fat, Cormane & van Furth, 1974). Direct immunofluorescence (DIF) staining of cryostat sections, taken from positive patch tests on ten patients with contact dermatitis caused by various antigens, using fluorescein-conjugated monospecific antisera to the five main heavy-chain classes of Ig and to complement, revealed the presence of lymphoid cells with membrane-bound Ig and complement (C3) in the dermis. This observation induced us to study the distribution pattern of Ig- and C3-bearing lymphocytes in the peripheral blood of patients with contact dermatitis and atopic dermatitis (Cormane, Husz & Hamerlinck, 1973). [ABSTRACT FROM AUTHOR]

The peak of blast response in primary, one-way mixed lymphocyte culture of CBA plus DBA/2m took place on culture day 6 to 7, whereafter the number of blasts per culture declined. Concomitanlly with the disappearance of blast cells from these cultures, the number of lymphocytes increased, indicating that a certain number of blasts reverts back to lymphocytes ("secondary lymphocytes"). The number of antigen- reactive tells in primary mixed culture (quantitated by hydroxyurea block) was on the order of 3% to 5%, whereas when the same cultures were reprimed with the original antigen, the number of antigen-reactive cells was on the order of 90%. Thus most lymphocytes surviving prolonged primary mixed lymphocyte culture are in fact secondary lymphocytes--that is, blast-derived. The secondary lymphocytes thus obtained responded promptly and in a biphasic manner to the original and H-2 cross-reactive stimulator cells in secondary mixed culture. The first, major response peak took place on culture day 2 to 3 and the second, minor peak on culture day 5 to 6. Although the secondary lymphocytes were sensitive to anti-0 plus complement, they did not respond to phytohemagglutinin. The secondary lymphocytes were themselves cytotoxic to relevant allogeneic target cells in vitro, and they were promptly reinduced to maximal cytotoxicity by a second priming with the original antigen. We suggest that these functions are characteristic to T memory cells primed against histoincompatible cells. [ABSTRACT FROM AUTHOR]

The surface characteristics of the mouse spleen cells mediating antibody-dependent cytotoxicity (ADCC) against antigen-coated chicken erythrocytes have been studied by several different column fractionation methods. The major effector cells in this system were shown to be surface-adherent and could be depleted from spleen cells by passage through glass-bead ovalbumin/anti-OA immune complex columns (Fc receptor-binding), glass-bead immunoglobulin/anti-mouse Ig columns (Fc receptor- and surface immunoglobulin-binding), and glass-bead mouse Ig/rabbit (Fab')2-anti-mouse Ig or Sephadex G-200/rabbit anti-mouse Ig columns (surface immunoglobulin-binding). The concentration of EDTA in the medium used to fractionate the cells played a significant role in determining whether surface immunoglobulin could be demonstrated on the ADCC effector cells. From these results, the conclusion was drawn that ADCC on the part of mouse spleen cells could be mediated by surface-adherent, Fc receptor-positive cells bearing surface immonoglobulin of unknown origin. The possibility that ADCC can be mediated by a heterogenous population of cells in the mouse spleen is discussed. [ABSTRACT FROM AUTHOR]

The cytotoxicity of human peripheral blood lymphocytes (PBL), after a 6-day allogeneic stimulation in unidirectional mixed lymphocyte culture (UMLC), was studied. PBLs stimulated with phytohemagglutinin (PHA) and labeled with 51Cr were used as target cells. The effector cells were incubated with the target cells at a 100:1 ratio for 6 hr. The amount of isotope released into the supernatant was used to calculate lysis. Cell-mediated lympholysis (CML) was specific, as shown by an innocent-bystander experiment and by the lack of lysis of target cells autologous with the effector cells. The specific lysis had the following features: linear increase between 2 and 8 hr of incubation, linear increase with the logarithm of the number of effector cells, and inhibition by EDTA and by cytochalasin B. Under the UMLC conditions used, potent effector cells were present already on day 4. A reduction in the number of stimulating cells to one third of the number of responding cells in UMLC resulted in a decrease of thymidine incorporation and in an increase of CML. The significance of CML for transplantation biology is discussed. [ABSTRACT FROM AUTHOR]

This article reports on the histological and serological features of experimental autoimmune thymitis in guinea pigs. The injection into animals of homogenates of certain tissues, notably thyroid, brain and testis, in complete Freund's adjuvant (CFA), produces a damaging immune reaction in the corresponding tissue of the immunized animal. The evidence that guinea pigs injected with thymus or muscle in CFA developed experimental autoimmune thymitis was based essentially on histological appearances, these being collections of lymphocytes in the medulla which distorted and compressed the line reticulin fibers at the cortico-medullary junction.