I. Gery

Immunoglobulin E antibodies to milk proteins

Ninety‐eight sera of normal and hospitalized infants were tested for IgE antibodies against milk antigens. These antibodies were detected by the radioimmunodiffusion (RID) technique using rabbit anti‐human IgE and prick tests of the skin.

The effect of irradiation on the release of lymphocyte-activating factor (laf).

Abstract Peritoneal cells from irradiated mice released two to three times more lymphocyte-activating factor (LAF) than did the cells from untreated controls. Similar results were obtained with unfractionated or enriched adherent cells. On the other hand, irradiation of adherent cells in vitro did not affect the level of factor released.

Transformation of rabbit lymphocytes by specific antigens.

Summary Lymphocytes from the blood of rabbits immunized with extracts of bovine or rat heart or with human IgG, reacted in vitro when cultured with the specific antigen. The reaction consisted of intense blast transformation, mitotic activity and incorporation of H3-thymidine. The level of response was found to be dose-dependent. Some unstimulated (control) cultures showed moderate “spontaneous” blast formation, without, however, mitotic activity or thymidine uptake.

ENDOTOXIN AS ADJUVANT IN AUTOIMMUNITY TO CARDIAC TISSUE.

Summary and conclusion Endotoxin administered together with homologous heart tissue homogenate in rats had a marked adjuvant effect in production of circulating anti-heart antibodies. This effect was greater than that of Freunds complete adjuvant and was abolished when the endotoxin was given separately, before or after the homogenate. Focal infiltrative myocarditis was seen in some of the animals but could be attributed equally to the endotoxin as to the administered antigen. It is suggested that the autoimmune process can be partially explained on the basis of modification of tissue antigen by linkage to endotoxin.

Potentiation of the T lymphocyte response to mitogens: V. Inhibition of the response to Concanavalin A by supraoptimal doses or by other lectins and its aversion by LAF☆

Abstract The enhanced thymidine incorporation in murine lymphocytes induced by Concanavalin A (Con A) was markedly inhibited in the presence of other lectins, which are poorly mitogenic (phytohemagglutinin {PHA} or pokeweed mitogen), or non-mitogenic (soybean agglutinin {SBA}). The level of inhibition was found to be inversely proportional to the mitogenic effect of the lectins. Our results did not support the notions that the lectins inhibit the lymphocyte responses by competing with Con A, or by activating suppressor cells. Rather, the data suggest that the lectins cause cytotoxic or cytostatic effects. The effects of the inhibitory lectins were found to resemble those of supraoptimal doses of Con A. In particular, both effects were partly averted by the lymphocyte activating factor (LAF). The mitogenic effect of LAF was not inhibited by the non-mitogenic lectin, SBA, whereas the poor responses to PHA or to moderately supraoptimal doses of Con A were markedly potentiated by this factor. It is thus suggested that LAF activity counteracts the inhibitory processes provoked by the lectins.

Effects of in vivo Administered B. pertussis and Other Adjuvants on the Mitotic Responses of Lymphocytes in vitro

Intraperitoneal treatment of mice with adjuvants affects the in vitro response of their lymphocytes toward class-specific mitogen. Spleen cells from animals injected with Corynebacterium parvum organisms showed in some cases an increase in their response to all mitogens, while in other experiments, a moderate decrease in the reaction to T-specific mitogens (concanavalin A and phytohemagglutinin) was found. Injection of lipopolysaccharide (LPS) and in particular Bordetella pertussis bacteria, brought about a marked reduction in the response of spleen cells to B mitogens (LPS and PPD) but had little or no effect on the reaction to the T mitogens. Intraperitoneal administration of B. pertussis caused a marked depletion of lymph nodes and a high level of lymphocytosis. Blood cells of the treated mice showed an increased response to T mitogens, whereas mesenterial lymph node cultures reacted higher than the controls to LPS and without stimulation. No change was noted in the responses of cells from the axillary lymph nodes of these pertussis-treated mice.

Peripheral Lymphocyte Populations

Blood lymphocytes from rabbits immunized against BSA were stimulated by this antigen in vitro and their response determined by the increase in uptake of 3HT. The rabbits