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P J Chalmers

Publications and source records attributed to P J Chalmers.

3 recordsLinked to original sources
PubMed1976

Characterization of serum factors modulating splenic cytotoxicity in a syngeneic rat tumour system.

During the terminal stages of tumour growth (6-8 weeks) in Wistar rats bearing a syngeneic squamous cell carcinoma (Sp1), their sera can block in vitro anti-tumour cytotoxicity by immune splenic T lymphocytes. At an earlier stage of tumour growth (4-6 weeks) the sera do not block this cytotoxicity, but can induce anti-tumour cytotoxicity by non-immune spleen cells in the absence of complement. Sera taken at these 2 stages of tumour growth have been fractionated by ion-exchange chromatography, using DEAE-cellulose. The fractions have been examined by immunoelectrophoresis and tested for anti-tumour reactivity. Blocking activity was found in the Week-8 serum fraction eluted with 0-005M phosphate buffer, pH 7-4, whilst the "cytotoxic" activity of Week-4 serum was eluted with 0-02M phosphate buffer, pH 6-2. It is suggested that different IgG sub-classes are responsible for the 2 activities.

Animals↗
PubMed1976

Characterization of cytotoxic spleen cells and effects of serum factors in a syngeneic rat tumour system.

Splenocytes from inbred Wistar rats bearing a syngeneic squamous cell carcinoma (Spl) were fractionated by several techniques to characterize the lymphoid cells cytotoxic to the tumour in vitro. The anti-tumour cytotoxicity is presumably mediated primarily by T lymphocytes because it was greatly reduced by removal of T lymphocytes with heterologous anti-T serum plus complement but not by removal of other cell types. Cytotoxicity could be blocked at the tumour cell but not at the effector cell by sera taken late in tumour growth. Sera taken earlier in tumour growth could induce cytolysis of tumour cells by normal splenocytes but only if the tumour cells were treated with serum and washed before addition of the effector cells. Although splenocytes from normal and tumour-bearing rats were equally effective at lysing antibody-coated target cells it is unlikely that this mechanism is important in vivo as sera from early in tumour growth onwards contained factors (immune complexes?) which inhibited antibody-induced lymphocytolysis.

Animals↗