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Biomedical subjects

B Perussia

Publications and source records attributed to B Perussia.

121 records · Page 7Linked to original sources
PubMed1977

Effect of ageing on surface IgG of human peripheral lymphocytes.

An increase in the percentage of IgG bearing peripheral blood lymphocytes is observed in aged subjects as compared with young ones. Such a finding is probably due to the presence, in 'aged' sera, of a higher concentration of immune complexes, bound to lymphocytes through their Fc or Complement receptors.

Adult↗
PubMed1977

Expression of Fc and complement receptors on T lymphocytes activated in vitro by phytohaemagglutinin (PHA).

In this work T-enriched lymphocyte populations (obtained from Ig-anti-Ig-Degalancoated columns) were studied for their surface markers, especially for Fc and complement receptors, before and after a pulse-PHA-stimulation. It has been demonstrated that activated T lymphocytes express on their surface both of these markers in high percentage. The hypothesis is discussed that B and T lymphocytes differ only with regard to the presence of surface immunoglobulins or the ability of forming spontaneous rosettes. On the contrary the other surface markers may probably be expressed when needed functionally by the cells.

Adult↗
PubMed1976

Complement receptors (C3b, C4b/C3d) unbalance on CLL lymphocytes.

A study of lymphocytes bearing C3b, C4b and C3d complement receptor (CRL) was performed on human peripheral blood from 16 healthy donors and 12 patients affected with Chronic Lymphatic Leukemia (CLL). In the latter group a clear rise of C3dCRL was demonstrated, when compared with immunoadherence receptors bearing lymphocytes. However, when compared with controls, also these latter were slightly augmented. Furthermore in CLL under treatment CRL populations showed the same profile as CLL: so it was suggested that the treatment reduced not selectively all the three types of CRL, within the population of sIg bearing lymphocytes. Here we discuss the hypothesis that, in CLL, the proliferating lymphocytes population is chiefly sIg+, C3d+/C3b-, C4b-, but also sIg+, C3d+/C3b+, C4b+.

Animals↗
PubMedDate not supplied

B and T cell surface markers on peripheral lymphocytes from diabetic patients.

A study of T and B cell surface markers was carried out on peripheral blood lymphocytes from diabetic patients, employing immunofluorescent staining for membrane Ig, and the E rosette test. According to the immunofluorescent studies the % of sIg bearing lymphocytes decreases with age; this trend is more evident in healthy individuals. Lymphocytes from diabetic patients posses a higher amount of membrane IgG than age-matched controls. It was only in the younger diabetic patients that a definite decrease was observed in the % of IgM bearing lymphocytes. The evaluation of E rosette-forming lymphocytes revealed a similar age-associated reduction both in diabetics and in controls. Some common features of the pattern of T and B cell markers on lymphocytes from younger diabetic patients and older controls suggest that the former undergo, at least from the immunological standpoint, a more precocious ageing process. It is possible that some metabolic disorders in lymphocyte activity may play a role in this, resulting in a deficiency in the control of immunological mechanisms.

Adult↗
PubMedDate not supplied

Comparative binding of murine and human monoclonal antibodies reacting with myelin-associated glycoprotein to myelin and human lymphocytes.

Human monoclonal IgM antibodies present in the blood of some patients with peripheral neuropathy and murine hybrid IgM antibodies C5 and C6, raised against myelin-associated glycoprotein, and HNK-1, raised against the human T cell line HSB-2, all bind to the carbohydrate moiety of myelin-associated glycoprotein. The relative avidity of the monoclonal antibodies was HNK-1 greater than C5/C6 much greater than human IgM, as determined in a competitive binding radioimmunoassay. HNK-1 bound myelin equally well at incubation temperatures between 4 degrees C and 37 degrees C; the human antibodies bound significantly only at 4 degrees C; and C6 bound best at 4 degrees C, less strongly at 20 degrees C and did not bind at 37 degrees C. All of the antibodies bound to a band corresponding to myelin-associated glycoprotein on immunoblots of human CNS myelin proteins in addition to several other antigens. Flow cytometric studies revealed that the murine but not the human antibodies bind to peripheral blood lymphocytes. Taken together, these data suggest that the antibodies probably recognize the same epitope but bind with different avidity.

Animals↗
PubMedDate not supplied

Immunological status of aged subjects with reference to serological evidence of autoimmunity.

When a group of 104 aged subjects was screened for autoimmune reactions, positive reactions for the rheumatoid factor and/or autoantibodies (ANA, anti-thyroid, PCA, anti-smooth muscle, anti-mitochondria) were recorded in 40.4%. Immunological functions were studied in 32 positive aged subjects, 32 age- and sex-matched negative controls, and 32 young subjects. Some differences attributable to the process of aging were quite evident, such as a depression in the percentage of E rosette forming peripheral lymphocytes and in their response to PHA, and an increase in the percentage of IgG-bearing peripheral lymphocytes and in the serum levels of IgA and three complement fractions (C'3, C'4, and C'3-PA). No clear-cut picture was noted when autoimmunity-positive and -negative, aged subjects were compared. However, some differences between sexes suggest that autoimmune reactions are linked to a depressed T cell function mainly in males, whereas the reverse is true for females.

Adult↗
PubMedDate not supplied

Soluble Fc gamma RIII (CD16) and immunoglobulin G levels in seminal plasma of men with immunological infertility.

Receptors for the Fc region of the immunoglobulin G (IgG) (Fc gamma R) have been recognized as a link between humoral and cellular immune responses. A soluble form of Fc gamma RIII (CD16) has been found in seminal plasma (SP), which may modulate immunosuppression of antisperm immune responses in the male and female reproductive tracts. SP from some individuals apparently have lower levels of Fc gamma RIII, but it is not known whether the diminished activities are due to low receptor concentration or steric interference from IgG. To test the hypothesis that different levels are due to steric interference, relative levels of Fc gamma RIII were measured in SP using monoclonal antibody 3G8 in an amplified enzyme-linked immunosorbent assay (ELISA) system. Men who were positive for antisperm antibodies (ASA) by Sperm Mar and direct immunobead assay (N = 26) and negative for ASA (N = 26) were tested. Individuals who were ASA positive had lower detectable levels than those who were ASA negative (t = 1.99, P = 0.05). Therefore, variation in Fc gamma RIII levels may be due to steric interference from IgG. IgG subclass concentrations in SP of both groups were determined using an ELISA method and compared to Fc gamma RIII levels. Slight correlations were seen for IgG1 (r2 = 0.237, P < 0.001), IgG2 (r2 = 0.204, P < 0.001), and total IgG (r2 = 0.299, P < 0.001) in relation to Fc gamma RIII levels in ASA-negative SP specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗