Enhancement of immune response of murine Peyer's patches by a diet supplemented with yogurt.

The first line of defense against pathogens that enter the host by the oral route involves the Peyer's Patches (PP). For centuries many populations of the mediterranean basin have empirically administered soured milk (yogurt) to prevent and treat diarrhoea and entero-colitis. Recent reports have offered evidence in favour of a possible influence of yogurt on the host's immunocompetence. Scope of the present study was to evaluate the influence of a diet supplemented with yogurt on the PP from BALB/c mice. The results reported here suggest that yogurt feeding potentiates the host's cell-mediated immune response by increasing the percentage of B lymphocytes and the PHA and LPS-induced proliferative responses of PP cell suspensions.

Influence of ofloxacin on murine Peyer's patch lymphocytes.

Several factors must be considered before the clinical impact of antimicrobials on the immune function can be determined. No data are available as yet on the influence of ofloxacin, a new fluoro-quinolone, on the lymphocytes of Peyer's patches. The present study offers evidence that murine Peyer's patches are influenced by ofloxacin administered by the oral route for seven days (15 mg/kg). No modifications of the percentage of the Thy 1,2 and SIg positive splenocytes and of the PHA and LPS-induced proliferative responses were observed studying cell suspensions from the spleen of the same animals. An immunotoxic effect of the compound on the cells of Peyer's patches or an impairment of their homing tendency has been postulated.

The effect of NPT 15392, 9-(erythro-2-hydroxy-3-nonyl)-6-hydroxypurine, on the phytohemagglutinin of OKT3+, OKT4+, OKT8+, and OKM1+ cell-depleted and undepleted peripheral blood mononuclear cells.

NPT 15392, 9-(erythro-2-hydroxy-3-nonyl)-6-hydroxypurine, has been reported to influence immunological responses involving different cell types. Herein data are obtained by studying the influence of NPT 15392 on the phytohemagglutinin (PHA)-induced proliferative responses of unfractionated peripheral blood lymphocytes (PBLs) and of cell suspensions, which have been depleted of the cell subsets recognized by the monoclonal antibodies OKT3, OKT4, OKT8, and OKM1, in an attempt to identify which cell types respond to NPT 15392 in the PHA-driven blast transformation assay. The proliferative responses of unfractionated peripheral blood lymphocytes are potentiated when the drug is employed at the concentration of 0.1 microgram/ml and inhibited when NPT 15392 is added to the cell suspensions at concentrations over 5 micrograms/ml. The data reported here suggest that this phenomenon is a composite effect, made up of a combination of the counteracting effects caused by the OKT4+ cells on the one hand, and the OKT8+ and OKM1+ cells on the other.

Anti-Ia reactivity in sera from subjects with Entamoeba histolytica infection.

Sera from 15 patients with Entamoeba histolytica infection were tested for anti T-cell antibodies by assessing cross-reacting specificities with the antigens defined by an anti-Ia hybridoma antibody. T cells prepared by sheep erythrocyte rosetting were preincubated with the test sera and then with the anti-Ia antibody. Binding of the specific monoclonal antibody was assessed by rosetting with ox erythrocytes conjugated with goat anti-mouse IgG. Eight sera from amoebic patients were found to block the binding of monoclonal mouse hybridoma anti Ia-antibody to T cells. Blocking of anti-Ia binding was not due to Fc IgG receptor binding by immune complexes nor was it HLA-DR restricted. T cells pre-treatment with the amoebic sera positive for anti-Ia activity showed reduced activity when tested in the autologous mixed lymphocyte reaction (AMLR). The results of our study seem to suggest the existence of specific anomalies of immunoregulation during E. histolytica infection which may play a role in inducing immune disregulation in vivo.