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Biomedical subjects

D Frasca

Publications and source records attributed to D Frasca.

61 records · Page 4Linked to original sources
PubMed1985

Enhancing effect of IFN-gamma on helper T cell activity and IL 2 production.

A single injection of young murine immune interferon (IFN-gamma) in young (3 mo) or old (14 to 24 mo) mice 3 days before carrier-priming significantly enhances helper T cell activity of their spleen cells. Maximal enhancement is attained when IFN-gamma is injected once immediately before priming or for 4 consecutive days from the time of priming. Helper activity for anti-TNP antibody response was titrated in vitro by adding graded numbers of spleen cells from HRBC-primed mice of a given age to cultures containing a constant number of spleen cells from 3-mo-old normal mice and TNP-HRBC. When T cell-enriched spleen cells from HRBC-primed young or old mice, uninjected or injected with IFN-gamma, were separated by nylon wool filtration into passed (Thi) and adherent (Th2) cells, the helper activity of both T cell subpopulations was found to be enhanced by IFN-gamma injection. Helper activity of purified Th1 and Th2 cells was also increased by their in vitro preincubation with IFN-gamma. Furthermore, interleukin 2 (IL 2) production by mitogen-activated spleen cells from young and old mice is enhanced by addition of IFN-gamma to cultures. These data altogether indicate that IFN-gamma plays an important role in immunoregulation of helper T cell activity.

Adjuvants, Immunologic↗
PubMedDate not supplied

Melatonin as immunomodulator in immunodeficient mice.

Melatonin, the main hormone of the pineal gland, when chronically injected into young mice or mice immunodepressed by aging or by cyclophosphamide treatment, is able to enhance the antibody response to a T-dependent antigen. The enhancement of the antibody response is associated with increased induction of T helper cell activity and IL-2 production, as evidenced in mice immunodepressed by aging or by cyclophosphamide treatment. These observations suggest that melatonin treatment may be successfully used in the therapy of immunodepressive conditions.

Adjuvants, Immunologic↗
PubMedDate not supplied

Recombinant cytokines as an approach to immune reconstitution in aging.

Aging is characterized by a decreased humoral and cell-mediated immunity to a large variety of exogenous antigens and by an increased propensity to autoantibody production, suggesting an age-related disregulation of the immune system. The decline in immune responsiveness to exogenous antigens has been attributed to thymus involution, consisting of a fall in the capacity to induce intrathymic T-cell growth and differentiation, and also to export mature T cells to the periphery. T-cell activation and secretion of soluble factors have been reported to change with aging, but, as with cytokines, the results are conflicting. We investigated the production of IL-2 and IFN-gamma (Th1 type) and IL-4 (Th2 type) cytokines by mitogen-activated spleen cells from young, adult and old mice and their regulation by the addition of a recombinant cytokine (IL-1 beta, IL-2, IL-3, IL-4, IL-12, IFN-gamma) at varying concentrations. The results indicate that cytokine production can be enhanced only when it is deficient, suggesting the possible use of recombinant cytokines as efficient immunomodulators in age-associated immune disorders.

Aging↗
PubMedDate not supplied

Psychological status and immunological parameters of institutionalized aged.

In the elderly, an impairment of the immune system could lead to increased incidence of infectious, neoplastic and autoimmune diseases; on the other hand, depression, which is the most common psychiatric problem in aged people, seems to be linked with alterations in immunological function. Thirteen institutionalized elderly subjects were studied to investigate the relationship between depression and immunological parameters. These subjects were selected as "healthy" according to the SENIEUR-EURAGE protocol and they belonged to a population already evaluated by our group--one year before--for psychological, endocrinological and immunological parameters. The lymphocyte mitotic response to PHA was greatly diminished in aged subjects, when compared to the adult controls. Depressed elderly showed impaired immunological function as compared with nondepressed ones, either "in vitro" or "in vivo". Lymphocyte stimulation with phytohemagglutinin (PHA), T cell growth factor (TCGF) production (induced by stimulation with PHA) and cutaneous delayed hypersensitivity (CDH) were reduced in depressed aged subjects. As far as lymphocyte proliferation with PHA in the whole group were concerned, no differences were found comparing the present results with those obtained in a former study. Although it is difficult to understand the significance of the immune imbalance associated with depression in the elderly, our results suggest that psychological status could influence the immunological functions in old people.

Aged↗