0000000000041554
AUTHOR
Antonio Tobia Colucci
In Vitro Cytokine Production by HLA-B8, DR3 Positive Subjects
It is well known that healthy subjects carrying the HLA-B8,DR3 haplotype may show an impairment of immune system, the T cells being the most affected. To gain insight into the mechanism(s) of the impairment displayed by these subjects, efforts have been centered on the study of in vitro cytokine production because of the pivotal role played by these mediators in the activation and control of several immune functions. The available results indicate that the ability to several immune functions. The available results indicate that the ability to produce interleukin-1 (IL-1), IL-2 and the soluble form of its receptor (sIL-2R) is impaired in HLA-B8,DR3 positive healthy subjects. To better charac…
The effect of age on mitogen responsive T cell precursors in human beings is completely restored by interleukin-2.
Abstract It is well known that the function of T lymphocytes is significantly impaired by advancing age. In the present study, attempts have been made to further characterize the T cell impairment of elderly subjects. Thus, we have performed limiting dilution microculture analysis to evaluate the precursor frequency of T lymphocytes responding to a mitogenic stimulus in old and young subjects. Furthermore we have evaluated the activity of recombinant interleukin-2 (rIL-2) on these cells. The results demonstrate that in older subjects the frequency of these precursors is significantly decreased. The in vitro treatment with rIL-2 increased the frequency of mitogen responsive T lymphocyte prec…
Hla-Bb, Dr3 T Cell Impairhent is Completely Restored by in Vitho Treatment with Interleukin-2
AbstractThe activity of recombinant interleukin-2 (rIL-2) on the in vitro lymphocyte proliferative response to phytohemagglutinin mitogen was investigated in healthy HLA-BB, DR3 positive and negative subjects. the response to mitogen, significantly decreased in HLA-BB, DR3 positive subjects, was completely restored by adding rIL-2. Moreover, in HLA-BB, DR3 positive subjects the in vitro treatment with rIL-2 significantly increased the reduced frequency of mitogen responsive T lymphocyte precursors, as assessed by limiting dilution analysis. These data suggest that a decrease in the size of the pool of T cell precursors able to produce IL-2 is responsible for the impairment of T cell functio…
Granulocyte and natural killer activity in the elderly
The deterioration of the immune system in ageing, 'immunosenescence', is thought to contribute to increased morbidity and mortality from infections and possibly autoimmune diseases and cancer. The most profound changes involve effector and immunoregulatory T-cell functions. Immunosenescence appears also to be related to changes in non specific immunity as well. In the present study we have assessed superoxide production, chemotaxis and the expression of the apoptosis-related molecule APO1/Fas (CD95) on neutrophils (PMN) from young and old subjects. Furthermore, we have measured the basal natural killer (NK) activity of young and elderly subjects and we have compared the number of CD16+ cell…
HLA-B8,DR3 haplotype affects lymphocyte blood levels
The number of lymphocytes in the blood is constant, pointing to an effective control of circulating lymphocyte values. The mechanisms of this regulation are uncertain, although it is likely that the number of blood lymphocytes is conditioned by hormones, homing factors and cytokines whose production is at least partly restrained by genetic factors. Particularly genetic factors linked to major histocompatibility complex (MHC) appear to be involved. In human beings a decreased number of blood lymphocytes has been described in healthy subjects carrying the Human Leucocyte Antigens (HLA) haplotype HLA-B8,DR3. In the present study, to inquire into the mechanisms of this lymphocyte decreased numb…
Hla-Bb,Dr3 Phenotype and the Antibody Response Against Epstein-Barr Virus
Antibodies against the viral capsid antigen (VCA) and nuclear antigens (EBNAs) of the Epstein-Barr virus (EBV) were determined in a sample of Sicilian population. A significant correlation was observed between HLA-BB,DR3 phenotype and reduced titres of antibodies to EBNAs, whereas HLA-BB,DR3 positive individuals displayed levels of antibodies to VCA comparable to those of HLA-BB,DR3 negative ones. These results further strenghten the suggestion that HLA-BB,DR3 positive subjects are low responders and that the depth of immune response depends on on the fashion of antigenic challenge.
Natural killer and lymphokine-activated killer activity in HLA-B8,DR3-positive subjects.
Abstract The haplotype HLA-B8,DR3 is over-represented in several autoimmune diseases, implying that genes predisposing people to these disorders are linked to this haplotype. In these diseases, various dysfunctions reflecting an impairment of the immune system have been found. Several reports indicate also that in HLA-B8,DR3-positive healthy subjects similar disorders may be demonstrated. In the present work, we have evaluated NK and LAK activity in these subjects. The study has been performed on monocyte-depleted peripheral blood MNCs by using the K-562 cell line as a target for NK activity and the HL-60 cell line for as a target LAK activity. LAK cells were obtained by incubating MNCs for…
gamma-Interferon, interleukin-4 and interleukin-6 in vitro production in old subjects.
It is well known that ageing is associated with various alterations of the lymphoid cell functions. Although both B and T cell are affected, the last appear to be more sensitive to ageing process. During the past years, to gain insight into thé mechanism(s) of this impairment, effort has been centered on the helper T cells specifically engaged in the production of interleukin-2 (IL-2) because of the pivotal role played by this cytokine in the activation of several immune functions. The results have demonstrated that the ability to produce IL-2 declines with age. In this paper we report the results of a study performed to determine the influence of age on the capacity to produce gamma-interf…