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J M Rolland

Publications and source records attributed to J M Rolland.

8 recordsLinked to original sources
PubMed1979

Detection of early lymphocyte activation by the fluorescent cell membrane probe N-phenyl-1-naphthylamine.

N-phenyl-1-naphthylamine (NPN) becomes fluorescent after binding to hydrophobic regions of cell membranes. Rat and mouse lymphoid cell suspensions stained with NPN showed changes in fluorescence emission 30 min after stimulation with mitogen or antigen, detected by microfluorimetry. Incubation of NPN-labelled mouse and rat thymocytes with phytohaemagglutinin or concanavalin A (Con A) caused an increase in mean cell fluorescence intensity. The response to Con A was inhibited by sodium azide and alpha-methyl mannoside. Stimulation of spleen cells from mice by allogeneic cells, or from tumour-bearing rats by tumour antigen consistently resulted in decreased fluorescence. The 'mixed lymphocyte response' detected only certain genetic differences between mouse strains and was proportional to the ratio of stimulator to responder cell number. The NPN staining procedure offers a simple and rapid assay of immunoreactivity and a means of studying early subcellular changes following lymphocyte activation.

1-Naphthylamine↗
PubMed1979

Rhodamine as a fluorescent probe of lymphocyte activation.

Fresh rat and mouse lymphoid cells have been labelled by stable linkage with tetramethylrhodamine isothiocyanate (TMRITC). A change in intensity, either an increase or decrease of the fluorescent emission of the cells, detected by microfluorimetry, was induced by mitogen stimulation or the mixed lymphocyte reaction. The change in fluorescence was observed within 3 h of mitogen stimulation and within 0.5 h in the mixed lymphocyte test. These early cellular responses were detectable consistently whether the labelling was done before or after mitogen stimulation; post-labelling only was studied in the mixed lymphocyte reaction. The method should provide a time-saving practical procedure for early detection of the lymphoid cell responses and would readily lend itself to flow cytofluorimetry for possible routine diagnostic use.

Animals↗
PubMed1976

Acridine orange fluorescence cytochemistry for detecting lymphocyte immunoreactivity.

Acridine orange staining reveals changes within 3 hours of in vitro stimulation of normal rat lymphocytes with mitogens, and of immune rat lymphocytes with the sensitizing antigen. An increased number of red fluorescent cytoplasmic organelles, presumably lysosomes are seen by fluorescence microscopy. Fluorimetry of the supernatants from stained cell suspensions suggests an overall decreased cell uptake of the dye. The microscopy and fluorimetry detected early events in the reaction of lymphocytes from tumour-bearing rats with the target tumour cells. It would appear that the changes in intracellular behaviour of the dye and in overall cell uptake after immune stimulation are a reflection of dissociated variations in internal and external cell membrane permeability, and may provide simple general means for recognizing cellular immune reactions.

Acridines↗
PubMed1976

Lymphoid cell fractionation by aggregated immunoglobulin-agarose columns.

Fractionation by columns of aggregated rat immunoglobulin (Agg Ig)-agarose was investigated as a method of separating different populations of lymphoid cells. With rat spleen cells, Agg Ig columns retained phagocytes, IgM- and IgG-antibody-forming-cells, cells mediating antibody- or PHA-induced lysis of chicken erythrocytes, and specifically immune splenocytes lytic to chicken erythrocytes without exogenous antibody. Agg Ig columns did not selectively remove 'B lymphocytes' (surface-Ig-bearing lymphocytes with or without EAC' receptors), or T lymphocytes capable of PHA-induced proliferation or graft-versus-host reactivity. With mouse spleen cells, Agg Ig columns retained alloimmune cytotoxic T cells.

Animals↗
PubMed1975

Analysis of inhibition of lymphocyte cytotoxicity in human colon carcinoma.

Serum inhibition of autochthonous lymphocyte cytotoxicity for tumour cells has been studied in 112 cases of colonic carcinoma. Addition of patient's serum to the lymphocyte tumour cell reaction mixture resulted in decreased cytotoxic reactivity of lymphocytes from 8 of 39 cytotoxic positive cases. It was also shown that sera could inhibit if separately preincubated with the lymphocytes (4 cases) or the target cells (2 cases). A tumour antigen preparation inhibited only when incubated with the lymphocytes. Inhibition by serum or antigen appeared to be specific for colon carcinoma. Four cases were specially studied to determine the mode of lymphocyte killing of tumour cells: in 3 it was mediated largely if not entirely by T lymphocytes, and in the fourth by both T and non-T cells. The findings support the view that T lymphocytes lose their anti-tumour reactivity in vivo in the presence of circulating antigen or antigen-antibody complexes such as would occur with progressive tumour growth.

Adult↗