Potentiation of T-Cell-Mediated Immunity by Selective Suppression of Antibody Formation With Cyclophosphamide

Abstract

Mice develop delayed-type hypersensitivity (DTH) ~ to heterologous red cells provided that dose and route of immunization are appropriately chosen (1). No adjuvant is needed, but the hypersensitivity will be transient and of low intensity if the dose of antigen is too large. For example, the dose of sheep red blood cells (SRBC) which gives maximum antibody production by intravenous immunization causes only a fleeting and barely discernible episode of hypersensitivity. The suppression of DTH is due to blocking factors which are formed by the interaction of antigen and antibody (2). The mediators of DTH can be freed from the influence of this normal inhibitory mechanism by splenectomy (2), by infection with BCG (3), or by treatment with drugs such as cyclophosphamide (CY) which act differentially on B lymphocytes (4-6). Since it was known that DTH reactions tend to be more prolonged in CY-treated animals (7, 8), this drug has been used in the present experiments to investigate the role of antibody in the regulation of T-cell activity. Materials and MethodsMethods have been described elsewhere for measuring hemagglutinin titers and DTH (2), and lymphoproliferative responses and numbers of plaque-forming cells (PFC) in popliteal lymph nodes (9, 10). The transfer of DTH with dissociated spleen cells has also been described (11).Anlmals.--Specific pathogen-free male and female mice of the CD-1 strain (Charles River Breeding Laboratories, Inc., Wilmington, Mass.) were used at 5 or 6 wk of age. C57BL mice, also from a specific pathogen-free colony, were used in one experiment.Antigens.--SRBC were obtained from the same animal twice weekly. Cells were collected and stored in Alsever's solution at 4°C. They were washed three times with normal saline and suspended to known density by hemacytometer count.

Application of a radiometric ear assay for studies of adjuvant arthritis in rats

“…Since previous work has shown that cyclophos- phamide evokes an enhanced delayed hypersensitivity response to SRBC by selectively destroying B lymphocytes in the mouse (14,15), an experiment was designed to test this finding in rats. Pretreatment with cyclophosphamide was required to obtain a positive ear response 14 days after intraperitoneal sensitization with SRBC in Sprague-Dawley rats (Table 3).…”

“…First, pretreatment with a single dose of cyclophosphamide allowed measurement 14 days later of a significant ear ratio in Sprague-Dawley rats sensitized with SRBC. This antigen usually produces a high antibody titer and a transient low-level DTH response (14,15). It has been previously reported (14,15) that cyclophosphamide depletes B lymphocytes and thus augments the DTH associated phenomena.…”

“…This antigen usually produces a high antibody titer and a transient low-level DTH response (14,15). It has been previously reported (14,15) that cyclophosphamide depletes B lymphocytes and thus augments the DTH associated phenomena. Second, the severity of the arthritic syndrome, as assessed by subjective scoring, hindlimb swelling, and the L/R T U d R ear ratio, was significantly inhibited by ALG.…”

Effect of Anapsos® in a murine model of experimental trichomoniasis

“…Regarding to the reference drugs assayed, cyclophosphamide was found to suppress humoral (Santos & Owen, 1966) as well as cell-mediated immunity (Poulter & Turk, 1972) when given at the same time as or after the antigen. However, when given before antigenic challenge, the drug enhances cell-mediated responses (Lagrange, 1974). Azathioprine is a powerful inhibitor of primary (innate) responses including allograft rejection and graft-versus-host responses, and FK-506 exerts its immunosuppressive action by the inhibition of IL-2 (Sigal & Dumont, 1992), IL-3, IL-4, GM-CSF, TNF-a, and IFN-y (Granelli-Piperno, 1988;Herold et al, 1986;Tokuda et al, 1994).…”

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“…The test tube containing blood was placed in a left sloping position 45 0 at 37 0 C for 01 hour. Supernatant fluid containing lymphocytes and leukocytes were removed using micropipette 15,16 .…”