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A Misefari

Publications and source records attributed to A Misefari.

At least 19 recordsLinked to original sources
PubMed1999

Interleukin-12 and interleukin-10 production by mononuclear phagocytic cells from breast cancer patients.

Interleukin-10 (IL-10) and Interleukin 12 (IL-12) generation may be regulated by a complex monocyte and macrophage-derived cytokine network and an impairment of the immune system can be observed in neoplastic disease. In this study, we examined the production of these cytokines by phagocytic cells, obtained from breast cancer (BCa)-bearing patients. Our results suggest that an increased IL-10 formation may represent an important regulatory pathway of IL-12 production by BCa mononuclear cells. In this report, we show that mononuclear cells of patients affected by breast cancer have a defective IL-12 production capability while generating higher amounts of IL-10.

Aged↗
PubMed1991

Prostaglandin E2-induced inhibition of the in vitro immune response by SRBC-stimulated human lymphocytes.

Exogenous PGE2 strongly inhibits the response of human lymphocyte cultures to SRBC. This effect is mediated through a T cell inhibition since non-T cells are not significantly affected. Indomethacin, which inhibits in this system lymphocyte endogenous PGE2 synthesis increases the in vitro immune response. The effect of indomethacin is overcame by exogenous PGE2. These data may be relevant for explaining the immunomodulatory role of PGE2 following antigen challenge.

Animals↗
PubMed1990

Senile dementia, Alzheimer type: a distinct entity in the immunosenescence?

Since previous data have provided conflicting results on immunoresponsiveness in senile dementia, Alzheimer type (SDAT), we evaluated the immune function in groups of SDAT patients and aged and young donors. In comparison to the younger subjects, SDAT and aged subjects did not exhibit significant differences in lymphocyte surface markers. Both groups of aged donors showed decreased B cell polyclonal responsiveness in a nonspecific T cell-driven B lymphocyte differentiation system. The use of an antigen-specific induction assay revealed an imbalance of T helper (Th) or T suppressor function in the elderly, while SDAT individuals were characterized by decreased Th activity. At the same time, aged individuals manifested an impairment of leukocyte-inhibiting factor (LIF) and lymphocyte-derived chemotactic factor production; a selective deficit of LIF release was seen in SDAT. Finally, elderly individuals displayed a decline of polymorphonuclear cell (PMN)-mediated functions and monocyte phagocytosis; only a decrease in PMN response was observed in SDAT. These results reveal discrepancies in impaired immune responses between SDAT and aging.

Adult↗
PubMed1989

Humoral and cellular immune responses to Salmonella typhi in patients with typhoid fever.

Humoral and cellular immune responses to Salmonella typhi have been studied in nine children with typhoid fever. By using dot immunobinding assay, anti-O-polysaccharide chain and antilipid A antibody titers have been evaluated during the course of the disease. Anti-O-polysaccharide chain antibody titers are lower at the first week and increase up to the third week of the infection. On the other hand, antilipid A antibody levels, which are already higher at the beginning of the disease, progressively augment during the following weeks. Concerning cellular immunity to S. typhi, antibacterial activity mediated by typhoid peripheral mononuclear cells has been determined. Results show this function to be depressed in the initial phase of typhoid, increasing with the time. Together, these data bring new insight on immunity in typhoid patients.

Antibodies, Bacterial↗
PubMed1989

Effects of substance P on the spontaneous binding of Salmonella minnesota R345 (Rb) to human peripheral blood lymphocytes.

The effects of substance P (SP) on Salmonella minnesota R345 (Rb) binding to human peripheral blood lymphocytes (PBL) were evaluated. Two parameters of bacterial cytoadherence were considered, namely the binding lymphocytes (BL) and the number of bound-bacteria/lymphocyte (BB). The results showed that SP inhibits both BL and BB in a significant manner. Furthermore, distribution of Salmonella binding to CD4+ and CD8+ lymphocytes was studied following SP pretreatment of lymphoid cells. This neuropeptide is able to hamper the bacterial cytoadherence to both T-cell subpopulations and, in particular, the inhibitory effect on the T-suppressor/cytotoxic subset was more pronounced. These findings are discussed in terms of SP intervention in the mechanism of host protection against invading microorganisms.

Antigens, CD↗
PubMed1989

Effect of prostaglandin E2 on pokeweed mitogen-activated human lymphocyte cultures.

It is shown that a short incubation of peripheral human lymphocytes with PGE2 is able to reduce the B cell differentiation induced by PWM. The target of PGE2 action appears to belong to T lymphocytes, since the treatment of non-T cells is uneffective in reducing the immune response. Both OKT4+ and OKT8+ subsets are sensitive to PGE2. Data concerning the role of endogenous as well as exogenous PGE2 either on unfractionated or fractionated OKT4+, OKT8+ and non-T lymphocytes are also discussed. The PGE2 inhibition on immunoglobulin synthesis in PWM-stimulated cultures seems to be mediated by a complex effect on both the T cell subsets.

Antibody-Producing Cells↗
PubMed1988

Depression by Fc gamma receptor ligands of SRBC-induced IgM-PFC generation in human blood mononuclear cell cultures.

A tissue-culture system to stimulate human peripheral blood mononuclear cells (PBMC) has been employed in which IgM plaque-forming cell (IgM PFC) generation in response to sheep erythrocytes (SRBC) is dependent on macrophages and T suppressor and helper lymphocytes. In this system PBMC from normal subjects give IgM PFC responses ranging from 26 to 938 PFC/culture. Heat-aggregated human IgG or immune complexes present for the duration of culture induce a significant depression of PFC. Unaggregated IgG has no effect on the response or only a moderate stimulatory effect at the highest dose. The results of these experiments are compatible with previous results in a murine system, which indicated that Fc gamma receptor-positive (Fc gamma R+) cells in the suppressor subset are the target for aggregated IgG and induce depression of the PFC response. A similar mechanism may be operating in the human system described here, although the target cell has not been identified. These results may reflect a mechanism of immunomodulation dependent on interaction of Fc receptor (FcR) ligands with FcR, which may play a role in the pathogenesis of immune complex disorders.

Antibody-Producing Cells↗
PubMed1988

Mononuclear cells from rheumatoid arthritis patients exhibit a depressed IgM response to sheep erythrocyte stimulation in vitro.

Human peripheral blood mononuclear cells when cultured for the short term (11 days) produce an optimal IgM plaque-forming cell (PFC) response to sheep erythrocytes, which is dependent on macrophages and T suppressor and helper lymphocytes. With this system we have investigated the PFC response of individuals with rheumatoid arthritis and compared this to the response of normal sex- and age-matched controls and of patients with osteoarthritis. The response of rheumatoid arthritis patients was significantly lower than that of subjects in the other two categories.

Animals↗
PubMed1985

Spontaneous rosette-forming lymphocyte sensitivity to prostaglandins in patients with cervical carcinoma after surgery.

We have reported a marked decrease of lymphocyte sensitivity to prostaglandins (PGs) in patients with untreated cervical carcinoma and other solid neoplasias. Particularly, Ea and ME rosette formation was inhibited only slightly by PGs in all cancer patients studied, as compared with the high inhibition values observed in normal individuals (Clin Immunol Immunopathol, 1981). In the present work, the PG-induced inhibition of Ea and ME rosette formation has been studied in patients with stage 0 cervical carcinoma up to 180 days after hysterectomy. It has been found that in these patients the PG sensitivity increased gradually up to or higher than the levels seen in normal control subjects. However, the PG sensitivity of Ea is restored earlier after surgery, while ME show a delayed recovery. Since the PG sensitivities correlate well with the clinical status of patients, it is suggested that such sensitivity may represent a useful test for following patients with cervical carcinoma.

Animals↗
PubMed1984

Depression of direct plaque-forming cell response in mouse spleen cell cultures by aggregated IgG2b-induced factors.

Mouse spleen cells were treated with concanavalin A (Con A) or aggregated mouse IgG2b for 48 h in culture. When cells thus treated were added to fresh mouse spleen cell cultures immunized with SRBC they depressed the response of B lymphocytes as measured by enumerating plaque forming cells (PFC) on the fourth day of culture. When supernatant from cells cultured with IgG2b was added to immunized cultures this resulted in depression of PFC generation similar to that observed by addition of treated cells. The depression observed was essentially in the same range as that observed by addition of Con A treated cells or their supernatant. These observations extend previous work suggesting that IgG2b-induced PFC depression may result from activation of suppressor T cells with elaboration of soluble suppressor factors. This mechanism of immunomodulation may be important in the pathogenesis of immune complex disorders.

Animals↗
PubMed1984

Isolation and purification of fetal calf serum factor promoting mouse erythrocyte rosette formation.

This paper describes the isolation and purification of a dialyzable mouse erythrocyte rosette-promoting factor (MERF) contained in fetal calf serum (FCS). All rosette-promoting activity of FCS appears to be due to a low molecular weight, ribonuclease-sensitive material with biological activity promoting the expression of mouse erythrocyte receptors on a subset of human B lymphocytes.

Adult↗
PubMed1983

Effect of prostaglandins on Fc-IgG receptors of human circulating T and B lymphocytes.

A short preincubation of human T and B lymphocyte subpopulations with physiologic or pharmacologic concentrations of PGs E2 and F1 alpha, but not with E1 and F2 alpha, markedly depresses the cell ability to bind immune complexes, through FcR-IgG. This effect appears to be relatively temperature-independent. These observations indicate that PG treatment of human lymphocytes may be useful to distinguish the subclasses of FcR-IgG-bearing T and B cells, which are sensible to the modulating effect of PGs.

Adult↗
PubMed1983

Effect of cyclooxygenase inhibitors on PGE2-sensitive human lymphocyte receptors.

A short preincubation of human T and B lymphocyte populations with exogenous Prostaglandin E2 (PGE2) markedly depresses the expression of surface receptors binding the Fc portion of IgG, sheep and mouse erythrocytes (FcR-IgG, Ea and ME receptors respectively). Using two cyclooxygenase inhibitors (indomethacin and meclofenamate) it is shown that endogenous PGE2 does not modify the activity of these lymphocyte surface receptors. The lymphocyte sensitivity to exogenous PGE2, which is released under various physiologic and pathologic stimuli, may represent present another method to subdivide human lymphocytes in distinct subsets.

Cyclooxygenase Inhibitors↗
PubMed1983

Redistribution of mouse spleen cell Fc receptors following treatment with mouse or human aggregated immunoglobulin G.

Mouse spleen cells treated with the Fc receptor ligands mouse IgG2b and human IgG, followed or not by a second antibody, exhibit different patterns of redistribution. In the work reported here we have examined the redistribution of Fc receptors (FcR) after binding of aggregated mouse IgG2b (Alg) or of Alg followed by anti-lg. We were particularly interested in learning whether binding of isologous Alg to FcR is followed by significant redistribution and shedding of Alg-FcR complexes. Mouse IgG2b alone will not induce capping even after 60 min at 37 degrees C. Human IgG induces some capping with minor shedding of complexes. Human IgG followed by anti-IgG readily induces capping by 15 min on 70% of the cells. This treatment also induces capping by 60 min at 20 degrees C on about 80% of the cells with a moderate degree of shedding of complexes. This is in agreement with the concept that the crosslinking required for FcR capping can be best induced with a second antibody. It is of interest, however, that heterologous IgG, unlike isologous, can induce a modest degree of capping and slight shedding even without the second antibody, suggesting that some crosslinking occurs with heterologous IgG.

Animals↗
PubMed1981

Cytochalasin A inhibits B-lymphocyte capping and activation by antigens.

Cytochalasin B (CB) has been shown to be a potent depressant of the antigen-induced clone expansion and terminal differentiation of mouse B-lymphocytes to antibody-forming cells. This effect could be the result of the microfilament-disrupting effect of CB with subsequent inhibition of antigen-sIg complex redistribution, a series of events which seems to be necessary for B-lymphocyte activation. CB is not very active in depressing capping and will inhibit glucose transport. To further investigate the mechanism of action of cytochalasins, the effect of cytochalasin A (CA) on cap formation and plaque-forming cell generation was studied, since CA is less inhibitory of glucose transport and more inhibitory of cap formation. The results presented here indicate that complexes of anti-Ig-sIg will be prevented from capping by as little as 1 microgram of CA, a quantity sufficient to depress markedly the generation of plaque-forming cells to SRBC in culture. These results further confirm our conclusion that the depression of B-lymphocyte activation may be related to the depression of cap formation. It also strongly suggested that inhibition of glucose transport can be regraded as a negligible factor in this depression.

Animals↗