Immunity to infection, allograft immunity and tumour immunity: parallels and contrasts

Normal Absolute Monocyte Count in Combination with Normal/High Absolute Lymphocyte Count at the Time of Relapse is Associated with Improved Survival in Patients with Early Relapsed Acute Myeloid Leukemia

This study aimed to examine the prognostic significance of peripheral absolute monocyte count (AMC) in combination with absolute lymphocyte count (ALC) at the time of relapse in a cohort of 57 patients with early relapsed (first complete remission <12 months) acute myeloid leukemia (AML). Both univariate and multivariate Cox proportional hazard regression analyses revealed that normal AMC in combination with normal/high ALC (versus low/high AMC in combination with low ALC) was significantly associated with improved OS. We concluded that the combination of AMC and ALC could be used as a prognostic marker for survival outcomes in early relapsed AML.

Thioglycolate medium decreases resistance to bacterial infection in mice

Brewer thioglycolate medium, a bacterial culture medium which is widely used as a nonspecific in vivo macrophage stimulant, was tested for its effect on mouse resistance to bacterial infection. Mice which did or did not receive thioglycolate medium were challenged with Listeria monocytogenes. Injection of thioglycolate medium significantly decreased the ability of the host to resist infection. This decreased resistance occurred whether thioglycolate medium was injected 0 to 9 days before, or 1 to 2 h after Listeria challenge. Bacteria grew considerably better in washed adherent peritoneal cells from thioglycolate medium-injected mice than in washed adherent peritoneal cells from normal mice. Thus, thioglycolate medium may ultimately cause a decrease in macrophage function.

Enhancement and metastasis after immunotherapy of ovine squamous-cell carcinoma

Extracts of ovine squamous-cell carcinoma (OSCC) prepared by different procedures, were injected at varying concentrations into 184 tumour-bearing sheep. At a total protein of 0.5 mg and greater, there was significant enhancement and metastasis in all 120 sheep examined. Extracts of OSCC containing less than 0.5 mg protein, or of human squamous-cell carcinoma and normal sheep skin containing high levels of protein, had no effect on subsequent tumour development. Extracts of foetal sheep skin at the 3mg-protein level produced significant enhancement and metastasis. The degree of enhancement was inversely proportional to the developmental stage of the tumour at the time of treatment.

Smooth-muscle-associated contractile protein in renal mesenchymal tumour cells and in transformed cells from DMN-injected rats

Cryostat sections and established in vitro cultures of dimethylnitrosamine(DMN)-induced renal mesenchymal tumours and monolayer cultures of transformed kidney cells derived from rats treated with a carcinogenic dose of DMN were examined by indirect immunofluorescence with human serum containing smooth muscle antibody. Eight mesenchymal tumours examined showed filamentous cytoplasmic staining of spindle cells infiltrating between renal tubules, whilst in normal kidneys interstitial cells were only weakly positive. In established in vitro cultures from 6 mesenchymal tumours, different patterns of staining were observed in morphologically different cell forms, ranging from fine filamentous staining in giant cells to diffuse cytoplasmic fluorescence in small bipolar cells, and cell outline staining in polygonal cells. In addition filamentous staining of microvillous projections and nucleolar staining were observed in some tumour cells. Monolayer cultures of transformed kidney cells showed strong staining of coarse, randomly-orientated cytoplasmic filaments, whilst fibroblasts cultured from normal rat kidney demonstrated an ordered array of fine, parallel filaments. Specificity of the immunofluorescent staining reaction was established by failure to obtain staining with normal serum, with smooth muscle antibody serum neutralized by homogenates of smooth muscle or extracts containing actin derived from smooth muscle. These results indicate that there is an apparent increase of actin-like contractile microfilaments in transformed cells and in renal mesenchymal tumours. The cytoplasmic contracile microfilaments in these cells may play a role in tumour cell mobility and invasion.

Macrophages and lymphoid tissues in mice with concomitant tumour immunity

The growth in mice of subcutaneous isografts of any of 5 methylcholanthrene-induced fibrosarcomas was associated with macrophage stimulation, reflected in an increased incidence of DNA-synthesizing cells among marcophages in the uninjected peritoneal cavity. This occurred at some stage with 4 tumours that induced concomitant immunity and one that did not. Some degree of splenomegaly also occurred with all 5 tumours. The spleens of all the tumour-bearing mice showed histological evidence of increased haemopoietic activity. Histological changes in the lymphoid elements of the spleen were very different with different tumours, ranging from lymphoid stimulation to lymphoid atrophy. The lymph nodes draining the sites of primary isografts which induced concomitant immunity showed signs of stimulation in the paracortical areas, followed by plasmacytopoiesis in the medullary areas. Stimulation of the paracortical areas was not detected in the nodes draining sites of injection of a tumour not inducing concomitant immunity. Nodes draining the sites of challenge isografts in mice exhibiting concomitant immunity showed plasmacytopiesis.