Biomedical subjects

F J Chrest

Publications and source records attributed to F J Chrest.

40 records · Page 3Linked to original sources

PubMed1983

Human B cell function in responder and non-responder individuals. II. The role of T helper cells in promoting the PWM-induced B cell production of immunoprotein.

Sorted OKT4+ cells treated with pokeweed mitogen (PWM) and subsequently X-irradiated were used as a source of helper T cells to examine human T and B cell function. PWM-induced immunoprotein synthesis by human peripheral blood lymphocytes was the model used to study the cellular interactions. PWM was shown to induce helper T cell function which caused non-PWM treated B cells to secrete immunoglobulin. PBL from certain individuals could not be induced by PWM to secrete Ig therefore allogeneic co-cultures of helper T cells and B cells were examined to define the defective cell population. Ig synthesis in allogeneic cultures of T and B cells was always greater than that observed in autologous cultures when cells from responders were assayed. However, when allogeneic cultures were initiated using B cells from a responder and PWM treated T cells from a non-responder and examined for Ig synthesis, the B cell responses were markedly lower than seen in the autologous responder cultures. In addition, PWM activated helper T cells from a responder induced a significantly higher Ig synthesis by B cells from a non-responder. These observations indicate that PBL from individuals who do not respond in a PWM driven Ig synthesis assay have relatively normal B cell function but are deficient in helper T cell function.

Antibodies, Monoclonal↗

PubMed1982

Oxidative metabolism and bactericidal capacity of polymorphonuclear leukocytes from normal young and aged adults.

The ability of polymorphonuclear leukocytes (PMNs) from young and old individuals to reduce nitroblue tetrazolium, to kill Staphylococcus aureus in vitro, and to generate superoxide was determined. Investigation of PMNs from 202 humans, aged 26 to 95 years, failed to demonstrate an age relationship in their ability to reduce nitroblue tetrazolium. The ability of PMNs from 20 young (M age 34 years) individuals to kill S. aureus in vitro did not differ from cells from 18 elderly (M age 68 years) persons. Mean production of superoxide in response to stimulation with latex particles was, however, significantly lower (P less than .001) in cells from elderly adults. These results suggest a heterogeneity in any age-associated defect in PMN function. Several aspects of PMN function need to be evaluated in order to describe overall PMN function in the elderly.

Adult↗

PubMed1982

Mitogenic activity of 12-O-tetradecanoyl phorbol-13-acetate on peripheral blood lymphocytes from young and aged adults.

The effect of age on the proliferative response to 12-O-tetradecanoyl phorbol-13-acetate (TPA) was examined using peripheral blood lymphocytes from 185 adults. TPA-induced DNA synthesis measured by cellular 3H-thymidine incorporation was found, like the responses of cells activated by PHA and Con A, to markedly diminish with advancing age. The presence of indomethacin (1 microgram/ml) or Ro 20-5720 (10 micrograms/ml) in TPA activated cell cultures, unlike PHA stimulated cultures, did not result in augmentation of 3H-thymidine incorporation by cells from elderly individuals. These results demonstrate that prostaglandin synthesizing suppressor cells are not responsible for the age-related depression of cellular immune function observed in TPA activated cells and confirm the observation that decreased production and/or utilization of soluble mediators, such as IL-2, may account for the diminished mitogen responsiveness of lymphocytes from elderly individuals.

Adult↗

PubMed1981

Enumeration of T lymphocyte subsets by monoclonal antibodies in young and aged humans.

The percentage and absolute number of peripheral blood mononuclear cells reactive with monoclonal antibodies identifying mature thymocytes and T cells (T3+), helper/inducer cells (T4+), and suppressor/cytotoxic cells (T8+) was determined in 19 young (mean age 35 yr) and 31 elderly (mean age 72 yr) individuals. The percent representation but not the absolute number of T cells (T3+) declined significantly (p less than 0.001) in the elderly, and the decline was attributable to both an absolute and relative decrease in the representation of the subpopulation of cytotoxic/suppressor (T8+) cells. The percentage and number of helper/inducer (T4+) T cells was comparable in both age groups.

Adult↗