Characterization of immunoregulatory T cells and lymphocytophilic antibodies in ulcerative colitis: analysis with monoclonal antibodies

Using monoclonal antibodies to the surface antigens or suppressor/cytotoxic (Anti-Leu-2a) and helper/inducer (Anti-Leu-3a) T cell subsets, we characterized peripheral lymphocytes in 27 patients with ulcerative colitis (UC) and 15 age-matched healthy controls by a fluorescence activated cell sorter. The patients with active UC had a reduced percentage (8.2 +/- 3.6%) of Anti-Leu-2a reactive subset in comparison with healthy controls (24.6 +/- 3.6%) (P less than 0.01). No significant change was found in the percentage of Anti-Leu-3a reactive T cells between the patients and the controls. Moreover, the relationship of lymphocytophilic antibodies found in the patients with UC to the T cell subsets was also examined. After a fraction of normal T cells was eliminated with treatment of the sera from patients with active UC, the percentage of T cells reactive with Anti-Leu-2a decreased from 25 to 15%, whereas the percentage of T cells reactive with Anti-Leu-3a increased from 40 to 70%. In the reciprocal study, the lymphocytophilic antibodies reacted with 80% of Leu-3a negative T cells and 65% of Leu-2a negative T cells. These results demonstrated that the lymphocytophilic antibodies found in UC patients are reactive with suppressor T cells and thus play an important role in the loss of peripheral suppressor cells in the active UC patients. The lymphocytophilic antibodies were also demonstrated to be reactive with non-helper, non-suppressor T cell subsets and some populations of helper T cells. These studies suggest the presence of immune-regulatory disturbances contributing the pathogenesis of UC.

[Effect of PSK on tumor-specific immunity induced by MMC-treated syngeneic tumor cells]

Immunization with MMC-treated EL-4 tumor cells could raise cytotoxic activity of non-adherent PE cells and resistance against rechallenge with small or medium doses of viable tumor cells. Administration of PSK augmented the generation of cytotoxic lymphocytes and the induction of resistance against rechallenge in mice immunized with such MMC-treated tumor cells. Augmented generation of cytotoxic lymphocytes may be ascribed to systemic effects of PSK but not to local effects in the peritoneal cavity, since augmenting effects of PSK were observed not only after intraperitoneal administration but also after oral administration. Either after intraperitoneal administration or after oral administration cytotoxic activity was detected in PE cells but not in spleen cells. Cytotoxic activity was detected in PE cells but not in spleen cells after intraperitoneal injections of MMC-treated tumor cells. Cytotoxic lymphocytes appear to differentiate to their mature form capable of being detected by 51Cr-release test principally at the site of direct graft rejection. Intraperitoneal administration of PSK was more effective in the augmentation of cytotoxicity of PE cells than oral administration. PSK may be able to have contact with precursors of cytotoxic lymphocytes more efficiently after intraperitoneal administration. Immunity against syngeneic tumor cells appears to be effective in elimination of small doses of tumor cells but to be overcome by medium or large doses of tumor cells at the rechallenge. Administration of PSK increased the threshold number to be eliminated by immune hosts. This finding seems to be important in relation to augmentation of resistance against metastasis or local implantation with a limited number of tumor cells.

Anti-colon antibody and lymphocytophilic antibody in ulcerative colitis

The presence of anti-colon antibody in the sera from patients with ulcerative colitis was demonstrated by antibody-dependent cell-mediated cytotoxicity (ADCC) assay. In addition, the high prevalence of lymphocytophilic antibody in the sera from patients with ulcerative colitis was obtained by fluorescence activated cell sorter (FACS) analysis. This lymphocytophilic antibody was absorbed by rat colon epithelial cells. Moreover the lymphocytes from ulcerative colitis showed lower binding capacity to this antibody, but acquired higher binding capacity after 20 hr incubation at 37 degrees C in vitro. These data suggest that ADCC may have some role in the pathogenesis of ulcerative colitis.

Entrance of cholera enterotoxin subunits into cells

Quantitative analysis of the staining of cholera enterotoxin on the surface of cells with specific antibodies against each subunit of cholera toxin, using a Fluorescence-Activated Cell Sorter, showed that not only subunit A but also subunit B penetrates the cell membrane. The detection of each subunit inside the cell was facilitated by the use of saponin, an agent which increases membrane permeability.

Experimental study on immunological reactions against the articular cartilage

In rats immunized with articular cartilage antigens, delayed hypersensitivity was detected by the macrophage migration inhibition test and delayed footpad reaction. Additionally, a proliferative response was found in the regional lymph nodes of immunized rats. The mixed addition of sensitized lymphocytes and antibodies exerted a cytotoxic effect on cultured chondrocytes. Articular damage including accelerated chondrolysis may have some relation to delayed hypersensitivity to autologous articular cartilage antigens.

Effects of cholera toxin on lymphoid system. I. Reduction of thymus cells after cholera toxin injection

One microgram of cholera toxin was injected intravenously into DDD and AKR mice and its effects on lymphoid tissues were examined at various intervals. A remarkable reduction of thymus cells were revealed from days 1 to 11 and from days 1 to 7 in DDD and AKR mice, respectively. Only slight effects were detected on the numbers of spleen cells and peripheral blood leukocytes in both strains throughout the observation period.

Effects of cholera toxin on the lymphoid system II. Selective augmentation of delayed footpad reaction in mice

Effects on immune responses to sheep erythrocytes (SRBC) were examined at various intervals after an intravenous injection of 1 microgram of cholera toxin in DDD and AKR mice. Delayed footpad reaction was augmented by pretreatment with cholera toxin 1, 7 or 10 days before immunization in both strains. The delayed reaction was not suppressed even in the presence of a prominent antibody production. In mice given cholera toxin, macrophage migration inhibition was not positive 5 days after immunization, but became weakly positive 10 days after immunization. Antibody production against SRBC especially of IgG class, was facilitated, when cholera toxin was given one day before immunization, on the other hand, antibody production was suppressed irrespective of immunizing routes and mouse strains. Similar results were observed in guinea pigs which were injected with 1 microgram of cholera toxin 0 or 7 days before immunization with bovine gamma globulin in complete or incomplete Freund's adjuvant. Erythema was augmented strikingly by cholera toxin, while macrophage migration inhibition was affected scarcely.

Importance of polymorphonuclear leucocytes in protection of mice against Escherichia coli

Bacterial growth and lethality of Escherichia coli infection of mice were enhanced by X-irradiation but not by treatment with carrageenan. Since carrageenan depletes macrophages but not polymorphonuclear leucocytes, it is concluded that protection against E. coli, at least in the early phases, depends mainly on polymorphonuclear leucocytes.

Decrease in cholera toxin-binding T cells in aged mice and human volunteers

The capacity of T cell-enriched populations of cells from mice and human volunteers to bind cholera toxin was analyzed by means of a fluorescence-activated cell sorter. In aged mice and humans, the number of cells capable of binding high concentrations of cholera toxin was lower than that in young mice and humans. The capacity to bind cholera toxin may be one of the useful indicators for the detection of aging in the immune system.

Cyclic AMP and immune responses: identification of prostaglandin E-producing cells in mouse spleens

Previous work has shown that normal mice respond to the intravenous injection of sheep erythrocytes (SRBC) with a transient increase in splenic cyclic AMP peaking after 2 minutes, and this cyclic AMP response has been shown to be due to prostaglandins (PGs) released from antigen-specific cells. In the present study, the cell type responsible for PG production in response to antigen was determined using a fluorescence-activated cell sorter (FACS) and an electron microscope. C57Bl/6 mice injected with SRBC showed a 2% increase of PGE-producing spleen cells relative to controls. In control mice injected with phosphate-buffered saline (PBS), 19% of the spleen cells produced PGE. An electron microscopic study of PGE-producing cells sorted on FACS showed that they were small lymphocytes and plasma cells. In addition, nude mice also increased the number of PGE-producing spleen cells in response to antigen. These findings suggest that lymphocytes involving at least B-cells respond to antigen with an increase in PGE production.