Procainamide induces a transitory impairment of B cell mitogenesis in beagle dogs.

Beagle dogs (3 to 6 years old) were treated with 100-150 mg procainamide HC1/kg/day. After 2, 5, and 9 months of treatment, peripheral blood lymphocytes were isolated and stimulated with pokeweed mitogen. The data demonstrated a suppression of mitogenesis only at 2 and 5 months after procainamide treatment.

Human class I MHC-restricted cytotoxic T-lymphocytes specific for human immunodeficiency virus envelope antigens.

Vaccines incorporating HIV envelope antigens are being developed for the prevention of AIDS. To determine whether HIV envelope antigens are recognized by human cytotoxic T-lymphocytes (CTL), we assessed class I MHC-restricted, HIV envelope antigen-specific cytotoxic activity of peripheral blood mononuclear cells (PBMC) from HIV-infected individuals, following in vitro stimulation. The target cells were human skin fibroblasts of known tissue type, infected with recombinant vaccinia viruses, either containing or lacking the whole HIV envelope gene.

[Action of isoprinosine on the "in vitro" activation of human lymphocytes (author's transl)].

The action of isoprinosine on lymphocytes stimulated by optimal or suboptimal concentrations of polyclonal mitogens (ConA and PWM) was studied in 3, 5 and 7-days cultures. In some experiments, varying concentrations of isoprinosine were added to lymphocyte cultures at variuos times. Isoprinosine exerted no effect on non stimulated cells but enhanced the proliferative response in the presence of mitogens.

A syndrome associating partial albinism and immunodeficiency.

Two unrelated patients with partial albinism, frequent pyogenic infections and acute episodes of fever, neutropenia and thrombocytopenia are described. Their pigmentary dilution was characterized by large clumps of pigments in the hair shafts and an accumulation of melanosomes in melanocytes. Melanocytes had few short dendritic expansions, and keratinocytes were hypopigmented.

Selective defect of precursor T cells associated with apparently normal B lymphocytes in severe combined immunodeficiency disease.

Two patients, one with an autosomal and the other a sex-linked form of severe combined immunodeficiency, had more than 95% B cells in their peripheral blood. Despite an increased absolute number of B lymphocytes, the patients were unable to produce serum antibodies. In each patient, geno- or pheno-identical bone marrow transplantation was followed by the visualization of a thymus shadow and the appearance of both cellular and humoral functions.

[E1Cold cytotoxic antibodies in kidney graft recipients].

Serial serum samples from 39 renal allograft recipients were screened for cold and warm cytotoxic antibodies before and after grafting. In the group of patients who developed antibodies only after grafting, 6 had cytotoxins reactive at 37 degree C and 5 had cytotoxins reactive at 15 degree. At one year, all the patients with cold alloantibodies has functioning grafts, but none of the patients with warm antibodies had kept their graft.

[Functional studies of T and B lymphocytes].

The means for analysing T-cell activities are very limited. Indeed, the numerical estimation of the changes which take place in human T lymphocytes had to rely solely on the observation of transformed cells (blasts). However, even if various mitogens appear selective for either T of B cells, we know that both types of lymphocytes are ultimately transformed into blasts.

[Modulation of lymphocyte proliferation by serum factors and lipopolysaccharide].

The in vitro proliferative response of rat lymphoctes culitivated in increasing concentrations of calf serm (LCS) was measured by the incorporation of 3H-thymidine. Results showed that in contrast to the response of PHA, the response to concanavlin A (conA) was greatly dependent on the concentration of serum in the medium. Kinetics of the response of ConA indicated that increasing concentrations of LCS unblocked the non-response to supraoptimal doses of the mitogen.

[In vitro stimulation of human T and B lymphocytes by lipopolysaccharide (LPS)].

The appearance of cells (CFC) having the property to cluster several layers of sheep red blood cells around themselves has been used in our laboratory as a marker for T cell activation. In this study, enumeration of stimulated T cells was carried out by this technique, whereas enumeration of B cells was carried out with surface Ig staining using fluorescein-labelled anti-Ig antibodies or F(ab)2 anti-Ig. Lymphocytes were stimulated in vitro for various lengths of time with the polyclonal mitogen PWM, the specific antigen Varidase and LPS added at culture initiation or 16 hours after beginning of culture.

Immunological activities of rat lymphocytes. I. Mitogenic responses and surface markers of lymphocytes from normal, thymectomized and B rats.

Lymphocytes from the peripheral blood, thoracic duct, spleen and lymph nodes of normal, thymectomized (TX) and thymectomized lethally irradiated marrow reconstituted (TXBM or B rats) Lewis rats were studied for their ability to proliferate in vitro in the presence of Con A or PHA. At the same time the lymphoid tissues of these animals were examined for the presence of B cells or T cells by immunofluorescence staining with antiserums to rat immunoglobulins or rat brain antigens (ARBS), respectively. The specificity of ARBS fort T cells was first established in both cytotoxicity and immunofluoresecnce studies with thymocytes as well as pruified T and B cells.

[Immunological activities of rat lymphocytes. III. --Isolation of differing subpopulations of lymphocytes by two techniques of T cell separation].

In previous studies we have isolated by density gradient separation a population of relatively dense T lymphocytes capable of inhibiting the mitogenic response to concanavalin A (ConA) and phytohaemagglutinin. In this study we compared two current methods of cell separation for their relative yield in T lymphocytes able or not to respond to Con A. The present results show that cells passed through nylon wool columns--in contrast to those obtained by removal of lymphocytes which bind erythrocyte-antibody-complement complex-partially lose their ability to respond to ConA.