Absence of CC chemokine ligand 2 results in an altered Th1/Th2 cytokine balance and failure to expel Trichuris muris infection

Despite a growing understanding of the role of cytokines in immunity to intestinal helminth infections, the importance of chemokines has been neglected. As a chemokine with both chemoattractive properties and an ability to shape the quality of the adaptive immune response, CC chemokine ligand 2 (CCL2) was investigated as an attractive candidate for controlling resistance to these types of infection, which require highly polarized Th cell responses. We show here for the first time that CCL2 plays an important role in the development of resistance to infection by the gastrointestinal nematode Trichuris muris. Thus, in the absence of CCL2, worm expulsion does not occur, and the lymph node draining the site of infection becomes a Th1-promoting environment. Elevated levels of IL-12 are produced by polarizing APCs, and the composition of the APC environment itself is perturbed, with reduced numbers of macrophages.

Leukaemia and anaemia in AKR/O mice I. Leukaemia characteristics, haematological variables and erythropoiesis stimulating factor(s)

AKR/O mice were used as a model for studying the pathogenesis of the anaemia accompanying leukaemia/lymphoma. The leukaemia incidence was 87%. Median age at diagnosis was 11.3 months. At diagnosis most of the mice had normal leukocyte counts. Clinically the mice divided into subgroups depending on the relative organ involvement: 1) thymoma group (n = 98), 2) spleen group (n = 144), 3) combined group (n = 27) and 4) mice with moderate organ changes (n = 216). Mice of group 1 were younger than the others, had a rapidly progressive disease, normal to elevated packed cell volume (PCV), and plasma erythropoietin (Epo) was normal or increased. Mice of group 2 were usually anaemic with high plasma Epo estimates and often elevated reticulocyte counts. Group 4 was the oldest group. Some of these mice were severely affected haematologically. Overall there was an inverse relation between PCV and plasma Epo estimate, indicating a normal Epo response to anaemia. In all groups increasing spleen size was associated with increased severity of anaemia and increased reticulocyte counts. The association between anaemia, elevated reticulocyte counts and spleen enlargement suggests haemolysis as a mechanism for anaemia, and also raises the question of compensatory spleen erythropoiesis.

Red blood cell metabolism in AKR mice in the prelymphomatous phase

The purpose of this study was to evaluate erythrokinetics and in vitro red blood cell (RBC) glucose utilization, 2,3-diphosphoglycerate production, and adenosine triphosphate levels following incubation in AKR mice from early in life until the onset of AKR lymphoma. Normal BALB/c mice served as controls. While hemoglobin concentration and RBC survival remained constant and similar in both groups of mice, the half disappearance time of injected radioactive 59Fe was longer and the 48-hr reappearance of 59Fe was less in AKR mice, compared with those of BALB/c mice. In vitro RBC metabolic studies indicated increased glucose utilization and 2,3-diphosphoglycerate production and decreased adenosine triphosphate levels following incubation in AKR RBC, in contrast to those in BALB/c RBC. RBC metabolic studies were also done in a small group of low leukemic C3H mice, and were similar to BALB/c mice. These differences became most marked in RBC from mice aged 15 to 30 weeks. Overt lymphoma began to occur after age 40 weeks. Hence, these erythropoietic changes occurred prior to the onset of lymphoma. The data imply a direct effect of virus infection on RBC or their precursors. The results are similar to changes in RBC metabolism noted in Rauscher-infected BALB/c mice. The broader implication of these findings in reference to viral host interactions and human leukemogenesis is discussed.