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Biomedical subjects

B M Balfour

Publications and source records attributed to B M Balfour.

At least 19 recordsLinked to original sources
PubMed1992

LFA-1-dependent OKT3-driven T cell clusters in common variable immunodeficiency.

The triggering of the TCR/CD3 complex by anti-CD3 (OKT3) antibody leads to the formation of T cell clusters. In cultures of T lymphocytes from most normal individuals, the peak of cluster formation occurs at 24 h, but with cells from patients with common variable immunodeficiency (CVI) it was seen earlier at 4-9 h; in addition, the clusters were larger than normal, particularly at 9 h. Cluster formation by CVI and normal cells was dependent on temperature and divalent cations, but did not require Fc receptors. Since OKT3 clustering is known to be dependent on the LFA-1/ICAM-1 adhesion system, the effect of monoclonal antibodies directed against these molecules was tested. A potent inhibitor was the antibody against the common beta chain of the integrin family (CD18), but of four MoAbs against the alpha chains (CD11), three inhibited and one stimulated T cell aggregate formation. Increased expression of LFA-1 or ICAM-1 on CVI patients' T cells could not be demonstrated. The accelerated clustering was therefore probably due to an increase in the proportion of cells carrying the activated form of LFA-1. The formation of large numbers of homotypic lymphocyte clusters might reduce the effective interaction between B and T cells, thus contributing to the depression of immunoglobulin synthesis observed in this disease.

Adolescent↗
PubMed1992

Lymphocyte macrophage interactions: peripolesis of human alveolar macrophages.

Peripolesis is a phenomenon in which a lymphocyte attaches itself to another cell, usually a macrophage or veiled cell, and proceeds to circle around it. In emperipolesis, a related phenomenon, the lymphocyte invaginates the target cell so deeply that it appears to be intracytoplasmic. Lung cells in bronchoalveolar lavage fluids from 20 patients were observed in the living state and filmed. Peripolesis of the alveolar macrophages was recorded in six cases. These patients included one case each of carcinoma of the bronchus, tuberculosis, sarcoidosis and asthma, while two patients had no detectable lung disease. Five out of the six positive cases were females. In every instance there was a high number of lymphocytes in the washing. The peripolesed macrophages were not injured, but temporary alteration of the cell membrane was noted in a minority of film sequences. The peripolesing cells were also examined by transmission and scanning electron microscopy. The lymphocyte was found to be closely attached to the surface of the macrophage, with no invagination and its ultrastructure was that of a small lymphocyte. Peripolesis is probably a physiological mechanism concerned with regulation of the immune response in the lung.

Adult↗
PubMed1990

Combined time-lapse cinematography and immuno-electron microscopy.

A method was developed to record interactions between mobile non-adherent immunocytes by time-lapse cinematography and then to study the same cells by immuno-electron microscopy, using monoclonal antibodies against surface components. For this purpose a modified stage was designed to fit an inverted microscope. The attachment included a device to cool the culture chamber with N2 gas, a micro-injector for monoclonal antibody and immuno-gold treatment, and two pairs of washing needles to change the medium without disturbance. The technique was first employed to study the formation of aggregates around the antigen-presenting cells in cultures containing cells from hyper-immunized animals. Recently peripheral blood cells from normal subjects and patients with immune deficiency syndromes were stimulated with pokeweed mitogen, cluster formation was recorded, and the cells were processed for immuno-electron microscopy.

Animals↗
PubMed1989

Comparison of antigen uptake by peritoneal macrophages and veiled cells from the thoracic duct using isotope-, FITC-, or gold-labelled antigen.

Veiled cells (VC), isolated from the thoracic duct of irradiated lymphadenectomized mice (MLNX) or peritoneal macrophages (PM phi were incubated with isotope-labelled hen egg lysozyme (HEL), purified protein derivative (PPD) or keyhole limpet haemocyanin (KLH) in vitro. About 2-10 times less antigen was associated with VC than with PM phi when measured in a Philips well-type scintillation counter. Autoradiographs of these cells indicated that 3-10% veiled cells had silver grains associated with them in contrast to 20-95% of the PM phi, depending on the type of antigen studied. It was also shown, from the distribution curves for grains in individual cells, that VC contained smaller numbers of grains than PM phi. Transmission electron microscopy using KLH conjugated with colloidal gold and immunofluorescence microscopy using KLH-FITC confirmed the results obtained from autoradiographs. However, measurements of the uptake of KLH-FITC by individual VC and PM phi using flow cytometry indicated that antigen was associated with nearly all VC in vitro but in much smaller amounts than with PM phi. Both VC and PM phi were capable of presenting HEL to primed T lymphocytes in vitro. These results are discussed in relation to the function of VC as accessory cells compared with PM phi.

Animals↗
PubMed1983

A study of cells present in lymph draining from a contact allergic reaction in pigs sensitized to DNFB.

Pigs were skin-painted with the contact sensitizing agent 1-fluoro 2,4 dinitrobenzene (DNFB) and lymph cells coming from the site were collected. Half the animals were sensitive to DNFB and half were normal controls. Special attention was paid to cells belonging to the veiled cell series. At 20 hr after DNFB application, some blast cells--on morphological grounds belonging to the veiled cell series--could be observed in the lymph of presensitized animals. But the most predominant finding in these pigs was that, approximately 30 hr after painting, the total cell output began to increase, reaching 10 times the normal level at 70 hr. The increase in the output of lymphoblasts was the most marked, suggesting peripheral sensitization. Such changes were not observed in normal animals. Here the most striking alterations were seen in the veiled cells. Some of these cells were moving ponderously about, apparently in pursuit of other lymph-borne cells, and this activity resulted in the formation of large cellular aggregates. Since it is known that veiled cells are involved in antigen handling, this behaviour probably facilitates the induction of the T-cell immune response. By contrast, the veiled cells from presensitized animals behaved in a more normal manner and the proportion found in aggregates was only briefly increased. In these animals lymphocytes were seen to interact with veiled cells in a manner reminiscent of peripolesis, apparently recognizing antigenic signals on the surface of the veiled cells. It is discussed that this might result in deletion of the antigen-presenting veiled cells, thus controlling the magnitude of the immune response.

Animals↗
PubMed1979

A study of cells present in peripheral lymph of pigs with special reference to a type of cell resembling the Langerhans cell.

Large mononuclear cells with long, actively moving cytoplasmic veils were observed in lymph coming from the skin. The enzyme histochemistry and ultrastructure of these cells suggested that they are related to epidermal Langerhans cells and interdigitating cells in the lymph node. It has been reported that Langerhans cells and interdigitating cells play a role in contact hypersensitivity by taking up antigen and presenting it to thymus-dependent lymphocytes, and it is likely that the veiled cells in the lymph are also involved. After skin-painting with 1-fluoro-2,4-dinitrobenzene (DNFB), the veiled cells in lymph coming from the site of painting became more active and were observed contacting other cells present in the lymph; many large cellular aggregates were found. Since neutrophilic leucocytes and mononuclear phagocytes were the predominating cell types in this lymph, there was no evidence for a massive recruitment of immunocompetent lymphocytes at the site of painting. Neonatally thymectomized pigs do not develop allergic reactivity to DNFB. It is of interest that the number of veiled cells and their ability to form large cellular aggregates was not affected in these animals. Therefore, it is unlikely that the defect in responsiveness can be attributed to a failure in the function of veiled cells.

Acid Phosphatase↗
PubMed1978

Functional anatomy of lymph nodes. II. Peripheral lymph-borne mononuclear cells.

In the rabbit a number of large mononuclear cells with ruffled surface membranes travel from the skin and superficial tissues of the leg, via the lymphatics, to the popliteal lymph node: they constitute 40-50% of the total cell population in the afferent lymph. About 10% of these cells are actively phagocytic when tested in vitro and about 3% are found to contain Langerhans granules. After isotopic labelling the majority of lymph-borne mononuclear cells can be detected within the regional node for at least 24 hours; most being located in the paracortex and a few in the interfollicular cortex. It is proposed that these cells, including those containing Langerhans granules, belong to the "mononuclear phagocyte system." Possible functions of these lymph-borne cells are discussed with particular reference to antigen transport.

Adenosine↗
PubMed1978

Contact sensitivity in the pig. II. Induction by intralymphatic infusion of DNP conjugated cells.

Pigs were skin painted with the contact sensitizing agent DNFB and afferent lymph was collected for the next 24 h. The lymph cells carried a small amount of DNP and were able to sensitize 40% of homologous recipients. Peripheral blood lymphocytes conjugated with DNFB in vitro to the same degree as afferent lymph cells sensitized 80% of autologous and 40% of homologous recipients: lymphocytes conjugated at higher levels sensitized 75% of animals in each group. Lightly conjugated cells were capable of survival and able to respond to stimulation by mitogens and their ability to sensitize autologous recipients was abolished by heat killing. Highly conjugated cells were not capable of survival, their sensitizing ability was not altered by heat killing and they were able to sensitize incompatible recipients. It is suggested that highly conjugated cells sensitize by a different mechanism which depends on the cooperation of non-lymphocytic cells, not easily mobilized from lymphoid tissue.

Animals↗
PubMed1978

Contact sensitivity in the pig. III. Induction by intralymphatic infusion of DNP-conjugated cell membranes and soluble proteins, free DNFB and some small molecular weight derivatives.

DNP-conjugated lymph node cell plasma membranes, thymocyte plasma membranes and red cell ghosts were prepared and tested for their ability to induce contact sensitivity, using pigs as experimental animals. Lymph node cell membranes and red cell ghosts were able to sensitize, provided the dose of DNP was very large, but thymocyte membrane failed to sensitize most pigs. DNP-conjugated lymph proteins coming from the site of application of DNFB were also able to sensitize if large amounts were administered, but free DNFB itself, infused directly into an afferent lymphatic, was much more efficient. Since DNFB can often be detected in lymph folowing skin painting, it may conjugate cells within the node which later contact the recirculating population of lymphocytes and so sensitize the animal by a central mechanism. The best-equipped cells would be the macrophage-like lymph cells which are closely related to the epidermal Langerhans cells and are known to migrate to the paracortex of the node.

Animals↗
PubMed1975

Stimulation of syngeneic and allogeneic lymphoid cells by tumour cells in vitro.

August and Wistar rat lymph node cells were found to respond well to PHA stimulation and in mixed lymphocyte culture, as determined by an increased incorporation of 3H-thymidine. August rat lymph node cells were also stimulated by incubation with irradiated syngeneic tumour cells. Allogeneic Wistar rat lymph node cells produced a larger response to the August tumour cells. The response of syngeneic and allogeneic lymph node cells was reduced by pretreating the tumour cells with a Wistar anti-tumour serum. Pretreating the tumour cells with sera from normal or tumour bearing rats also reduced the response of syngeneic lymph node cells but did not reduce the response of allogeneic lymph node cells.

Animals↗