Human spleen as a source of T cell growth factor

Human spleen cells were tested for the ability to produce T cell growth factor (TCGF) upon stimulation with PHA. Quantitative analysis of the amounts of TCGF produced under optimal conditions indicated that supernatants obtained from spleen cell cultures were approximately five times more active than those derived from peripheral blood leucocytes (PBL). Moreover, in contrast to PBL, there was no significant difference in TCGF production between individual spleen cell populations. Among splenic T cells, TG-depleted cell fractions were superior to TG-enriched cell fractions in producing TCGF upon PHA stimulation. These supernatants induced intense proliferation of blast cell populations isolated from mixed leucocyte-tumour cell cultures (MLTC) established with PBL and irradiated allogeneic myelogenous leukaemic cells. Within 7 days of culture in TCGF, the number of MLTC blast cells increased approximately 300-fold. Concomitantly, the lytic activity (on a per-cell basis) of these populations against the corresponding myelogenous leukaemic cell targets increased approximately 80-fold.

B lymphocytes in sarcoidosis

Twenty-six patients with active and inactive sarcoidosis were studied. Surface immunofluorescence techniques with polyvalent and monospecific antisera after resynthesis of intrinsic Ig, were employed to determine the number of B cells. The peroxidase positive cells were not included in the count. Percentage and absolute number of lymphocyte forming rosettes with mouse erythrocytes were also determined. Compared to normal controls the numbers of SmIg positive cells were practically unchanged. Moderate decrease in the absolute number of mouse rosette forming cells was found in active disease. Our results will be correlated with the staging of the disease.

T cell immune function in newborn infants

T cell immune function in 20 newborn infants was investigated. Previous studies showing increased spontaneous transformation and higher 3H-thymidine incorporation at lower PHA concentration in newborn infants were confirmed. A net increase in the number of active E rosette-forming lymphocytes and a slight decrease in the percentage of total E rosette-forming cells was also found. Our results suggest the presence of a subpopulation of activated T lymphocytes in the peripheral blood of newborns during the first days of life. Possible mechanisms of this activation are discussed.

Imbalances of T Cell Subpopulations in Patients with Atopic Diseases and Effect of Specific Immunotherapy

Reduced numbers of T cells with Fc receptors for IgG (TG cells) are present in blood samples of patients with respiratory allergic disease, mainly those with severe symptoms, TG cells have been previously shown to be suppressor in the pokeweed mitogen- (PWM) dependent B cell differentiation. T cells with Fc receptor for IgM (TM cells), which help immunoglobulin production, are in a normal range. After specific hyposensitization, resulting in a sharp improvement of clinical symptoms, TG cell subset reached normal values.

Imbalances of T cell subpopulations in patients with atopic diseases and effect of specific immunotherapy

Reduced numbers of T cells with Fc receptors for IgG (TG cells) are present in blood samples of patients with respiratory allergic disease, mainly those with severe symptoms. TG cells have been previously shown to be suppressor in the pokeweed mitogen- (PWM) dependent B cell differentiation. T cells with Fc receptor for IgM (TM cells), which help immunoglobulin production, are in a normal range. After specific hyposensitization, resulting in a sharp improvement of clinical symptoms, TG cell subset reached normal values.

Immunological features in chronic lymphocytic leukaemia (CLL) of T cell origin

Peripheral blood lymphocytes from a patient with chronic lymphocytic leukaemia of T cell origin were studied. The thymus derived nature of these lymphocytes was confirmed by surface markers, mitogen cultures, mixed lymphocyte reaction, cytotoxicity studies, and cytochemical stains. This case is notable for several clinical and laboratory findings. Among these, the benign clinical course, the reduced rate of serum immunoglobulins, the elevated number of active E rosettes, the increased PHA-induced response to low mitogen doses, the absence of PHA mediated cellular cytotoxicity, and the thy-like positivity to ANAE should be pointed out. Emphasis should be placed, however, on the loss of stimulatory ability in MLR. This last feature supports the hypothesis that these cells proliferate as a clone.