The immunologically specific retention of recirculating long-lived lymphocytes in lymph nodes stimulated by xenogeneic erythrocytes

Lymphocyte traffic through lymph nodes during cell shutdown

Antigenic challenge of lymph nodes in sheep has marked effects on lymphocyte traffic through lymph nodes. The non-specific effects include a marked reduction in lymphocyte output in efferent lymph without a corresponding decrease in lymph flow--a phenomenon known as cell shutdown. With certain antigens there is a total disappearance of B lymphocytes during cell shutdown. The phenomenon can be reproduced in unprimed lymph nodes whenever localized complement activation occurs within the node. This also induces the release of prostaglandins, particularly PGE2. These results suggest that cell shutdown might be a two-step process involving both complement and prostaglandins. Repeated stimulation of nodes with antigen also has considerable effects on the traffic of antigen-specific lymphocytes. Antigen localized within the node can promote the selective entry into the node of T lymphocytes specific for the challenge antigen. Consequently there is a net loss from the whole animal of T cells reactive to the challenge antigen. These results are discussed in relation to lymphocyte recirculation through antigen-stimulated lymph nodes.

On T cell memory: arguments for antigen dependence

Memory is a hallmark of the immune system. Considerable progress has been made towards understanding B cell memory, but T cell memory remains poorly understood and its nature is controversial. There is good evidence that B cell memory is driven by antigen, but the antigen dependence of T cell memory is still being debated. For several years we have investigated the nature, duration and antigen dependence of different aspects of CD8+ T cell memory and this review will discuss our findings as well as how and why they differ from some other results. As others, we find that antigen, due to proliferation of antigen-specific T cell clones, induces a shift in the T cell repertoire which remains detectable for years as an elevated cytotoxic T cell precursor frequency (CTLp) in lymphoid organs. Also in the absence of antigen, in vitro assays for T cell memory which invariably isolate memory T cells from these lymphoid organs therefore remain positive. In contrast, immunity against reinfection with a pathogen requires more than just elevated numbers of CTLp in lymphoid organs. Since reinfection usually takes place via peripheral nonlymphoid tissue, these CTLp have to a) efficiently extravasate and patrol through such tissues, and b) be immediately able to exert effector function in case of reinfection. Both functions, require a certain level of activation which critically depends on T cell stimulation by persisting antigen.

Coordinate expression of beta 1 and beta 2 integrin "activation" epitopes during T cell responses in secondary lymphoid tissue

The monoclonal antibodies (mAb) 15/7 and 24 recognize unique activation-dependent, conformational epitopes on beta 1 and beta 2-integrins, respectively. The expression of both of these epitopes closely correlates with the ligand binding ability of their respective integrins, and thus serves as indicators of functional integrin "activation". Here, we have used six-parameter flow cytometry to examine the expression of these epitopes and conventional beta 1- and beta 2-integrin epitopes during human T cell activation in secondary lymphoid tissues in vivo, focusing particularly on the virgin to memory/effector cell transition. Fresh tonsil lymphocytes were stained with mAb against conventional or activation-dependent integrin epitopes, followed by staining with mAb against CD3, CD45RA, and CD45RO, thus allowing the determination of integrin epitope expression on virgin (CD3+) T cells (CD45RA+/RO-to+/-), memory/effector (CD45RA-/RO++) T cells, and T cells undergoing the virgin to memory/effector transition: transition region-1 (T1; CD45RA+to++/RO+); -2 (T2; CD45RA++/RO++); and -3 (T3; CD45RA+/RO++). Conventional beta 1- and beta 2-integrin epitopes progressively increase during the virgin to T3 stages of the transition in tonsil, in keeping with the generally higher levels of these adhesion molecules on memory/effector vs. virgin T cells. Expression of both the beta 1 (15/7)- and beta 2 (24)-integrin activation epitopes first appears on transitional T cells, and is maintained on a relatively constant number of cells (averaging 25-30%) throughout the T1-T3 stages. These epitopes are also noted on a subset of activated memory/effector T cells. Importantly, on both transitional and activated memory/effector T cell subsets, the expression patterns of the 15/7 and 24 epitopes vs. a variety of T cell activation antigens are identical, and the expression of these epitopes relative to each other is linearly correlated, findings strongly supporting the coordinate activation of beta 1 and beta 2 integrins during T cell activation in vivo. These results provide the first evidence of integrin activation during an in vivo immunologic response, and demonstrate the usefulness of mAb recognizing conformational epitopes and multiparameter flow cytometry in delineating the dynamic interplay of adhesion molecules during complex physiologic processes.

Tissue specific binding of lymphocytes to the thyroid gland of BB/W rats may be an early event in the development of thyroiditis

Thyroiditis occurs in about 50% of diabetic Bio Breeding/Worcester (BB/W) rats. In order to investigate the earliest stages of lymphocyte homing to the thyroid gland in the development of experimental autoimmune thyroiditis, we measured the amount of trapping of peripheral blood lymphocytes (PBL) from BB/W rats to the thyroid gland of syngeneic recipient animals. PBL, from donor normal or diabetic BB/W rats, labelled with 51Cr, were injected, i.v., into normal, "potentially diabetic" or diabetic BB/W recipients. After 24 hr the rats were sacrificed and the radioactivity of selected individual organs counted. Results were calculated as % binding of 51Cr-labelled PBL/unit weight of tissue and expressed as a binding index by comparing to binding to recipient blood lymphocytes. A significant binding index was taken as greater than 1.0. PBL from diabetic or normal donor BB/W rats were shown to bind significantly to the thyroid gland of 8 out of 19 "potentially diabetic" or diabetic recipient syngeneic rats, but to none of the normal (non diabetic) recipients tested. Sixty percent of "potentially diabetic" BB/W rats and 50% of diabetic rats at 3-4 months of age showed a significant level of binding of donor lymphocytes from syngeneic diabetic or normal animals to their thyroid gland, while, at 5-6 months the proportion of recipient rats giving positive tests was much less (17%). The source of the donor lymphocytes (diabetic, or normal) did not significantly influence the binding. Lymphocyte binding to pancreas was not significantly greater than to control tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Specific selection of antigen-reactive lymphocytes into antigenically stimulated lymph nodes in sheep

Sheep were primed to a variety of antigens and the efferent lymphatic from a popliteal lymph node was cannulated. The cannulated node was challenged repeatedly with PPD and all the lymph and cells removed from the animal. During this time the PBL were monitored for reactivity to all antigens (purified protein derivative of tuberculin [PPD], johnin, and keyhole limpet hemocyanin [KLH]) by the vitro transformation assay. The response of these cells to PPD was found to be gradually eliminated after repeated challenge of the cannulated node with that antigen. The response to the other antigens was unimpaired. No depletion of this response to PPD occurred in cannulated sheep when the antigen was given into a noncannulated node. In vivo delayed-type hypersensitivity skin test and helper T cell assays confirmed that there is a specific selection of antigen-reactive cells from the recirculating lymphocyte pool into antigen-stimulated lymph nodes.

Selection of antigen-specific cells by adherence to allogeneic cell monolayers: cytolytic activity, graft-vs.-host activity and numbers of adherent and nonadherent cells

Rat lymph node cells taken at the peak of cytolytic activity following a skin allograft were separated into adherent and nonadherent fractions by incubation on monolayers of thoracic duct lymphocytes either of the same strain as the graft donor or of an Ag-B different strain. In the face of a 3-fold enrichment of cytolytic activity in the adherent cells and a 3-fold depletion in the nonadherent cells there was no detectable partition of graft-vs-host (GVH) activity. Supplementary experiments supported the simplest interpretation of this finding, namely that the antigen receptors on GVH-reactive cells did not influence their adherence in this system. Similarly, there was no partition of the GVH activity of nonimmune lymph node cells by adherence. Labeling lymph node cells with either radioactive uridine or thymidine in vitro, suggested that about 20% of DNA-synthesizing cells in the immune population adhered because of antigen recognition.

Lymphocyte migratory pathways in adjuvant disease. I. Distribution of 51Cr-labeled thoracic duct lymph-borne

Evidence for selective extravasation of thoracic duct lymph-borne cells, derived from rats with adjuvant disease, within joints of normal or adjuvant arthritic recipients was sough by adoptive transfer of radiolabeled cells. Control studies were carried out in parallel using thoracic ducts cells from normal donors. No increased homing of lymph-borne cells to inflamed portions of the limbs was detected when cells from adjuvant arthritic donors were compared with those of normal controls. Inflammatory changes, ie, adjuvant-induced disease, in the recipient produced a significant nonspecific enhancement of extravasation; cells from normal and adjuvant arthritic donors responded equally well. One difference in migratory behavior between lymph-borne cells from adjuvant arthritic and normal animals was the increased ability of the former to localize within certain lymph nodes. A possible association between this traffic and the development of chronic inflammatory processes within joints is discussed.

Migratory behavior of lymphocytes with specific reactivity to alloantigens. II. Selective recruitment to lymphoid cell allografts and their draining lymph nodes

A dual-antigen, dual-isotope assay has been used to monitor the migratory behavior of selectively labeled antiallogeneic lymphocytes in mice challenged subcutaneously in all four foot pads with semiallogeneic spleen cells. 3H-labeled anti-C3H and 14C-labeled anti-C57BL lymphocytes of DBA/2J origin were pooled and adoptively transferred to multiple groups of previously challenged DBA/2J recipients. In some of the studies, separate groups of recipients were challenged with either CDF or BDF spleen cells in all four paws, whereas in others CDF spleen cells were used to challenge the right paws of each mouse in the group and BDF spleen cells to challenge the left paws of each mouse in the group. At intervals varying from 24 to 96 h after challenge, a subgroup of four mice from each appropriate group was sacrificed and the relative numbers of anti-C3H and anti-C57BL lymphocytes present in the challenged paws, draining lymph nodes, and other tissues of each mouse were inferred from the mean 3H/14C ratios of the respective tissues of that subgroup. The results of these studies firmly establish that specific antiallogeneic lymphocytes are selectively recruited to the paws and draining lymph nodes of mice challenged subcutaneously in the foot pads with semiallogeneic spleen cells and are deleted from their circulating blood and nondraining lymph nodes. A mechanism for antigen-induced selective recruitment and its possible functional significance in tumor immunology are discussed.

Competition for cytotoxic immune capacity against a 'syngeneic' mouse tumour distributed at two sites

Normal C3H mice will develop fatal ascites after the intraperitoneal injection of as few as 100 BP8 cells. However, mice can be immunized so that they can specifically reject an intraperitoneal challenge of 10(7) of these C3H-derived tumour cells. This paper investigates a phenomenon in which the capacity of immunized mice to reject an intraperitoneal challenge of tumour cells is lost between two to seven days after tumour cells have been given subcutaneously. Investigation of this temporary loss of capacity to reject the intraperitoneal challenge of tumour suggests that this might be due to the attraction of cytotoxic immunity to the site of subcutaneous injection. The possibility that this phenomenon is due to blocking factors, tumour overload, suppressor cells or enhancing antibody has been investigated but experimental results are given which do not favour these explanations.

Architectural alteration of lymphatic tissue produced by extracorporeal thoracic duct filtration

Removal of recirculating lymphocytes from the lymph of calves by extracorporeal thoracic duct filtration results in a state of immunounresponsiveness. Accompanying this is histological evidence of lymphocyte depletion from the lymph organs and structures of the body. Lymph nodes, spleen, hemolymph nodes, Peyer's patches, and thymus appear depleted of the recirculating small lymphocyte. We find this closed model of lymphocyte depletion effective and free of seyere problems with infections and physiological alterations as experienced in mechanical removal, extracorporeal irradiation, and open thoracic duct fistulas.

The effects of antigen on the migration of recirculating lymphocytes through single lymph nodes

The increased input of RL into LN starts within 3 h after antigenic stimulation and is due to an increase in the number of RL passing through a LN. It is not associated with an altered transit time through a LN of the majority of RL and it cannot occur in the absence of high endothelial PCV. The immediate decrease in the output of RL from an antigen-stimulated LN is due to a delay in the exit from that LN of RL which had entered the LN before antigen was given. The decrease in cell output from a LN after antigen administration affects blast cells produced within the LN as well as small lymphocytes and is not specific for RL. There are at least two distinct mechanisms controlling the migration of RL through an antigen-stimulated LN. The first controls the increased input of RL which occurs only through high endothelial PCV. The second controls the immediate decrease in cell output, which although it does not occur at the level of the high endothelial PCV, can only occur in organized lymphoid tissue. The increased input of RL into an antigen-stimulated LN and the decreased cell output from the LN can occur independently and are possibly controlled by different mechanisms.

Characteristics of immunological memory in mice. II. Resistance of nonrecirculating memory cells to antigen-mediated suppression of the secondary antibody response

Mice were primed and subsequently challenged at various times with subcutaneous injections of sheep erythrocytes, and some characteristics of the secondary responses in the draining brachial and axillary lymph nodes were investigated. It was found that the secondary response within primed nodes was resistant to immunological preemption, a competition-like phenomenon which severely depresses primary responses. Since it was also shown that circulating memory cells could be inhibited by preempting injections of antigen, it was concluded that the resistance of primed nodes to preemption was due to the presence within them of a nonrecirculating subpopulation of memory cells. The size of this population was dependent both on the amount of priming antigen and the time after priming. The observation that the response given by these cells remained unaffected by doses of antigen which could depress a primary response does not favor the view that suppression of immune responses by preemption or antigenic competition is due to a factor which acts directly and indiscriminately on all immunologically competent cells.

Selective DNA synthesis by cells specifically localizing in response to xenogeneic erythrocytes

The present studies have shown that cells capable of specific localization in response to challenge with CRBC or SRBC synthesize DNA very rapidly during the period from 2-5 days (peak 3 days) post primary immunization. This has been done by incubating the antigenically stimulated lymphoid cells with [(3)H] or [(14)C]thymidine in vitro for 45 min before adoptive transfer to syngeneic recipients. Specifically localizing cells (SLC) labeled in this way may ultimately account for up to 50% of the (3)H or (14)C present in a set of specifically challenged lymph nodes 3 days later. The data presented are consistent with the hypothesis that SLC numerically constitute only a very small fraction of the total number of recirculating lymphocytes trapped in antigenically stimulated lymph nodes, and that the demonstration of specific localization therefore depends upon selectively labeling these SLC relative to other recirculating cells. Attempts to selectively label the RNA of SLC with the precursor uridine have to date met with only very limited success.

Mechanism of graft-versus-host-induced lymphadenopathy in mice. Trapping vs. proliferation

Graft-vs.-host (GVH)-induced lymphadenopathy of the popliteal lymph node has been produced in C57BL/6 x A/J F(1) (BAF(1)) mice by injecting A/J spleen cells into the rear footpads. By giving (51)Cr-labeled BAF(1) lymphoid cells intravenously to the hosts, 24 h before sacrifice, we have demonstrated that a large portion of the GVH-induced lymphadenopathy is due to the trapping of circuating lymphocytes in the challenged lymph nodes. Most of the remaining enlargement can be attributed to proliferation of host cells within the reacting lymph nodes. Conditions have been defined under which the weights and [(14)C]thymidine incorporation of the popliteal nodes can be plotted against the dose of injected A/J spleen cells on a double-log scale to give a linear dose-response. The popliteal lymph node GVH assay is a simple and effective means of quantitating immune reactivity to histocompatibility antigens in mice.

Contact sensitivity in the mouse. IX. The role of immunological and non-immunological inflammation in the movement of lymphocytes to immunized lymph nodes

Normal mice were immunized with picryl chloride. ⁵¹Cr-labelled normal lymph node cells were injected 1–10 days afterwards and the net arrival of radioactivity at the draining lymph nodes estimated. The net arrival at normal unimmunized lymph nodes was 5.3 per cent of the injected dose. This rose to 13.4 per cent 1 day after immunization and then gradually declined.

This increased arrival caused by picryl chloride was reduced in mice rendered unresponsive by the repeated injection of picryl sulphonic acid or given a single injection of picryl sulphonic acid 1–6 days before immunization. Blast cells labelled with ¹²⁵IUDR from lymph nodes immunized with an unrelated agent also showed an increased arrival at draining lymph nodes. This increased arrival was reduced in unresponsive mice painted with picryl chloride.

A single intravenous injection of picryl sulphonic acid increased the arrival of normal lymph node cells at lymph nodes 1 day later and this effect was also diminished in mice rendered unresponsive by repeated injections of picryl sulphonic acid.

The arrival of normal lymph node cells at the spleen was reduced by painting with picryl chloride or by a single injection of picryl sulphonic acid given a few days beforehand.

Painting the ears of unimmunized mice with picryl chloride increased the arrival of normal lymph node cells and blast cells at the ears. However, the arrival was unaffected by pretreatment with picryl sulphonic acid.

It was concluded that the increased arrival of cells in lymph nodes caused by picryl chloride and picryl sulphonic acid had both an immunological and a chemical inflammatory component. In contrast the arrival at painted ears lacked an immunological component. This provided evidence for antibody, or antigen-sensitive cells in apparently unimmunized mice which rapidly release pharmacologically active agents on exposure to antigen.