Cell-mediated immunity: correlation of mixed-leucocyte-macrophage migration inhibition with delayed-type hypersensitivity after immunization and donor-specific transfer of cell migration inhibition by dialyzable leucocyte extract

Dialysable leukocyte extracts modify the course of experimental paracoccidioidomycosis in the Syrian hamster

The effect of dialysable leukocyte extracts (DLE) obtained from hamsters immunized with Paracoccidioides brasiliensis (immune DLE) and from non-immunized hamsters (non-immune DLE) was studied in hamsters inoculated with P. brasiliensis by the intratesticular route. Treatment with immune or non-immune DLE was started during the third week of infection and was repeated at 7, 11, 15 and 19 weeks. A group of untreated infected animals was used as control. Animals were submitted to the delayed hypersensitivity skin test to P. brasiliensis antigen (PbAg) in vivo and assayed in vitro by the macrophage migration inhibition test in the presence of Phytohemagglutinin (PHA) and PbAg and by immunodiffusion for specific antibody. The animals were sacrificed at 4, 8, 12, 16 and 20 weeks. The morphology and extension of the lesions were studied at the inoculation site, and in lymph nodes, lungs, liver, spleen and kidneys. In contrast to the controls, animals treated with both DLEs maintained a positive cell-mediated immune response throughout the experiment and developed less extensive infection with a significantly lower number of fungi in the lesions. The results suggest that immune and non-immune DLE preparations modified the evolution of experimental paracoccidioidomycosis with equal efficiency. This similarity may be explained by the immunoregulatory activities of both extracts.

Leukocyte migration inhibition in bacillus Calmette-Guérin vaccinated healthy adults and in tuberculosis assayed by a rapid photoelectric procedure

A sensitive photoelectric method was used for reading migrations of human peripheral blood leukocytes from agarose microdroplets. Its rapidity enabled the use of a wide range (12 logs) of in vitro concentrations of antigen. Inhibition of migration of leukocytes (LMI) of healthy subjects having had BCG vaccination in childhood was found to occur in two zones of PPD concentrations, one high, from 10(-1) to 1000 micrograms/ml with a peak at 100 micrograms/ml, and one low, from 10(-8) to 10(-2) micrograms/ml. While three-fifths of subjects showed high zone LMI, in one-fifth it was bizonal and in another fifth observed only in the low zone. In patients with active pulmonary tuberculosis LMI, prior to all treatment, was reduced, absent, or replaced by enhanced migration, particularly in the low zone or in both zones. One and a half to four months after treatment LMI was found to be bizonal, enhanced migration having disappeared. These observations suggest the participation of two cell populations with widely different sensitivity to PPD in LMI in tuberculous and BCG vaccinated subjects and the presence of migration stimulatory lymphokine(s) during active tuberculosis.