Cellular response and resistance to the primary infection of rats and mice with Nematospiroides dubius

BNCT induced immunomodulatory effects contribute to mammary tumor inhibition

In the United States, breast cancer is one of the most common and the second leading cause of cancer-related death in women. Treatment modalities for mammary tumor are surgical removal of the tumor tissue followed by either chemotherapy or radiotherapy or both. Radiation therapy is a whole body irradiation regimen that suppresses the immune system leaving hosts susceptible to infection or secondary tumors. Boron neutron capture therapy (BNCT) in that regard is more selective, the cells that are mostly affected are those that are loaded with 109 or more 10B atoms. Previously, we have described that liposomal encapsulation of boron-rich compounds such as TAC and MAC deliver a high payload to the tumor tissue when injected intravenously. Here we report that liposome-mediated boron delivery to the tumor is inversely proportional to the size of the murine mammary (EMT-6) tumors. The plausible reason for the inverse ratio of boron and EMT-6 tumor size is the necrosis in these tumors, which is more prominent in the large tumors. The large tumors also have receding blood vessels contributing further to poor boron delivery to these tumors. We next report that the presence of boron in blood is essential for the effects of BNCT on EMT-6 tumor inhibition as direct injection of boron-rich liposomes did not provide any added advantage in inhibition of EMT-6 tumor in BALB/c mice following irradiation despite having a significantly higher amount of boron in the tumor tissue. BNCT reaction in PBMCs resulted in the modification of these cells to anti-tumor phenotype. In this study, we report the immunomodulatory effects of BNCT when boron-rich compounds are delivered systemically.

Supplementation of heterologous complement induces anti-Thy-1.1 nephritis in the Mongolian gerbil (Meriones unguiculatus)

Anti-Thy-1.1 nephritis in the rat is a popular experimental model for mesangial proliferative glomerulonephritis (GN). This model is characterized by direct binding of anti-Thy-1.1 antibody with Thy-1.1 antigen expressed on mesangial cells (MCs) of glomeruli in the rat. A single injection of anti-rat thymocyte serum (ARTS) results in GN with proteinuria and extensive mesangiolysis. Development of mesangiolysis and proteinuria are complement-dependent. We previously demonstrated Thy-1.1 antigen, similar to the rat, in thymocytes, brain cells and MCs of the kidney in the Mongolian gerbil (MG). In this study, we attempted to develop a MG nephritis model, but an injection of ARTS did not induce GN. An additional injection of guinea pig serum as a complement after ARTS injection resulted in anti-Thy-1.1 nephritis in MG. Degeneration of MCs and neutrophil infiltration were observed 1 hr after GP serum injection. Mesangiolysis and fibrin exudation occurred 12 hr after the injection and MC proliferation was apparent 7 days after the injection. In the complement-dependent hemolytic test, MG serum could not hemolyze sheep erythrocytes. These results suggested low activity, or depletion of some factors, in complements of MG serum.

Heligmosomoides polygyrus: A model for chronic gastrointestinal helminthiasis

Establishment of chronic infections and strain-dependent variation in resistance to challenge infections are well-known features of the relationship between mice and the intestinal nematode parasite Heligmosomoides polygyrus. Here, Fernando Monroy and Javier Enriquez examine host responses, immunogenic and nonimmunogenic antigens of the parasite, and parasite immune evasion strategies in this useful laboratory mouse model of nematode parasitism of mammals.

Excretory-secretory antigens from adult Nematospiroides dubius

Adult Nematospiroides dubius excretory-secretory (ES) products were collected from worms cultured in vitro, radiolabelled and separated by sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE). The components were characterized and assessed for molecular weight (MW) after autoradiography and gel staining, for antigenicity in immunoblots, for sensitivity to protease enzymes, and for carbohydrate content. ES contained at least 18 denatured components from MW less than 20,000 to greater than 200,000. At least one of the surface proteins of adults was found with the ES antigens recovered when adults were cultured in vitro. Molecules with MW 200,000, 78,000 and 60,000 were glycoproteins and reacted with immune mouse serum in Western blots. The dominant ES, MW 60,000 component stained with periodic acid-Schiff (PAS), bound lectins with affinity for D-mannose, and was resistant to peptic and tryptic but not V8 protease digestion.

Low molecular weight immunosuppressors secreted by adult Nematospiroides dubius

Adult Nematospiroides dubius excretory-secretory products (ES) were collected from worms cultured in vitro, separated by sodium dodecyl sulphate--polyacrylamide gel electrophoresis (SDS-PAGE) into four fractions (FI-IV), electroeluted and assessed for their ability to inhibit the proliferation of mouse lymphocytes stimulated by mitogens in vitro. The proliferation of mitogen- and ES-stimulated mouse spleen lymphocytes from normal and infected mice was inhibited by low mol. wt ES F-IV (less than 26,000).

The role of free oxygen radicals in the expulsion of primary infections of Nippostrongylus brasiliensis

The many and varied pathological, immunological and physiological manifestations of infection with Nippostrongylus brasiliensis may be unified by considering the role of leukocyte-generated free oxygen radicals in worm expulsion. Aside from directly damaging the adult stage of N.brasiliensis and possibly leading to its elimination from the small intestine, free radicals may also damage intestinal cells, thereby contributing to the gut pathology characteristic of infection. gamma-Interferon (and possibly tumour necrosis factor) may be involved in the initiation of free radical generation in response to N. brasiliensis and may also contribute to various side effects of infection such as hypertriglyceridaemia and cachexia. gamma-Interferon may initiate free radical generation via the agency of protein kinase C, an enzyme that can induce various additional responses including lysosomal enzyme and amine secretion and arachidonic acid metabolism. The possible interactions between these mediators and free radicals are subtle and diverse and may profoundly affect the course of infection.