scholarly journals Trypanosoma cruzi. Factors modifying ingestion and fate of blood form trypomastigotes.

1980 ◽  
Vol 152 (2) ◽  
pp. 447-451 ◽  
Author(s):  
N Nogueira ◽  
S Chaplan ◽  
Z Cohn

Blood form trypomastigotes of the Y and CL strains of Trypanosoma cruzi were tested for their ability to enter and infect mouse peritoneal macrophages. Both strains failed to enter macrophages in appreciable numbers, whereas metacyclic trypomastigotes purified from acellular cultures were ingested with ease. Macrophage parasitization was enhanced manyfold after the removal of an antiphagocytic substance by trypsinization. This occurred without modification of parasite viability. Opsonization with hyperimmune mouse serum also enhanced the uptake of blood form trypomastigotes by macrophages. This effect was mediated by the macrophage Fc receptor. The effects of serum and trypsinization were additive at high parasite:cell ratios. Neither trypsin-mediated nor antibody-dependent opsonization of the organisms modified the fate of either strain within resident macrophages. However, lymphokine-activated macrophages were capable of destroying both strains, and antibody opsonization further enhanced this process.

1980 ◽  
Vol 29 (2) ◽  
pp. 477-482 ◽  
Author(s):  
P K Maiti ◽  
R Kumar ◽  
L N Mohapatra

Mouse peritoneal macrophages were infected in vitro with Candida albicans, and the phagocytic and candidacidal activities were estimated by microscopic examination of Giemsa-stained cells. Activated macrophages obtained from either BCG-vaccinated animals or by in vitro exposure of normal macrophages to phytohemagglutinin-induced lymphokines exhibited higher phagocytic and candidacidal activities than did normal macrophages. However, activated macrophages obtained by in vitro exposure of macrophages to candida-induced lymphokines exhibited the highest phagocytic and candidacidal activities. The incorporation of immune mouse serum into the culture medium also enhanced the phagocytic and candidacidal activities of the normal macrophages but failed to improve the function of the activated macrophages. These results suggest that both activated macrophages and antibodies may be required for controlling candida infections in mice.


1983 ◽  
Vol 62 (1) ◽  
pp. 287-299
Author(s):  
M.N. Meirelles ◽  
A. Martinez-Palomo ◽  
T. Souto-Padron ◽  
W. De Souza

Untreated mouse peritoneal macrophages as well as macrophages treated with concanavalin A (ConA) were incubated in the presence of untreated or ConA-treated epimastigotes and trypomastigotes of Trypanosoma cruzi. Treatment of epimastigotes or trypomastigotes with ConA increased or decreased their uptake by macrophages, respectively. Treatment of their macrophages with ConA reduced by 70% and increased by five times the ingestion of epimastigotes and trypomastigotes, respectively. These results are discussed in relation to previous studies on the mobility of ConA receptors in the membrane of the parasite. Using fluorescein- or ferritin-labelled ConA we observed that ConA binding sites located on the plasma membrane of macrophages are internalized during endocytosis of T. cruzi, and observed in association with the membrane of the endocytic vacuole. Vacuoles without parasites showed a uniform distribution of ConA binding sites, while these sites were distributed in patches in vacuoles containing parasites. These results, in association with others previously reported, suggest the involvement of glycoproteins and/or glycolipids localized on the cell surface of T. cruzi and macrophages during the T. cruzi-macrophage interaction.


1975 ◽  
Vol 141 (6) ◽  
pp. 1278-1290 ◽  
Author(s):  
C Bianco ◽  
F M Griffin ◽  
S C Silverstein

We have examined the roles of Fc receptors and complement receptors in mediating the interaction of sensitized sheep erythrocytes (E) with activated and with nonactivated mouse peritoneal macrophages. Both activated and nonactivated macrophages ingest IgG-coated erythrocytes [E(IgG)]; activated cells intest 1.5-2 times as man E(IgG) as do nonactivated macrophages. Thus, there is a quantitative difference in Fc receptor-mediated ingestion between activated and nonactivated macrophages. There is, however, a qualitative difference in function of complement receptors of activated and nonactivated macrophages. Nonactivated macrophages avidly bind complement-coated E [E(IgM)Ia1, but do not ingest them to a significant degree. Activated macrophages, on the other hand, bind and ingest E(IgM)C. The possibility of Fc receptor participation in mediating ingestion of E(IgM)C by activated macrophages was eliminated by blocking Fc receptors with an antimacrophage IgG fraction. Activated macrophages treated with antimacrophage IgG did not ingest E(igG) but did ingest both E(IgM)C AND E(IgM)C. Nonactivated macrophages treated with antimacrophage IgG did not interact at all with E(IgG). These cells bound, but did not ingest, E(IgM)C and E(IgM)C. Complement receptor-mediated ingestion is a marker for macrophage activation and may be physiologically important in the elimination of complement-coated particles.


1986 ◽  
Vol 28 (4) ◽  
pp. 205-212 ◽  
Author(s):  
Tecia Ulisses de Carvalho ◽  
Wanderley de Souza

The infectivity amastigotes of Trypanosoma cruzi, isolated from the supernatant of the J774G8 macrophage-like cell line infected with trypomastigotes to normal macrophages in vitro was tested. After a period of 1 h of T. cruzi-macrophage interaction about 2% of the mouse peritoneal macrophages had ingested amastigotes. In contrast 12% of the macrophages had ingested epimastigotes. Treatment of the amastigotes with trypsin did not interfere with their ingestion by macrophages. Once inside the macrophages the amastigotes divided and after some days transformed into trypomastigotes. When i.p. inoculated into mice the amastigotes were highly infective, inducing high levels of parasitaemia and tissue parasitism. As previously described for trypomastigotes, amastigotes were not lysed when incubated in the presence of fresh guinea-pig serum. Contrasting with what has been described for trypomastigotes, the resistance of amastigotes to complement-mediated lysis persisted after treatment with trypsin.


1979 ◽  
Vol 40 (1) ◽  
pp. 257-270
Author(s):  
C. Tickle ◽  
A. Crawley

The invasiveness of mouse lymphocytes and thymocytes, rabbit peritoneal neutrophil granulocytes (PMNs), mouse peritoneal macrophages (both activated and non-activated) and pig endothelial cells was assayed by implanting these cells to the chick wing bud. Cells of each type moved into the wing mesenchyme, although activated macrophages invaded poorly. PMNs were the most invasive cells and had moved well into the limb after only a few hours. PMNs, lymphocytes and thymocytes were ingested by wing mesenchyme cells. Endothelial cells, however, ingested chick blood cells. The implanted cells showed differences in ability to survive in the limb: PMNs disappeared rapidly, lymphocytes and thymocytes sometimes persisted for 24 h, while grafts of macrophages and endothelial cells were present at 24 h. Mechanisms which might be involved in the invasiveness of these cells, and also in their different abilities to survive in the chick wing, are discussed with particular reference to the production of plasminogen activator.


1973 ◽  
Vol 137 (3) ◽  
pp. 807-820 ◽  
Author(s):  
H. Melsom ◽  
R. Seljelid

A cytotoxic effect of mouse peritoneal macrophages against syngeneic and allogeneic erythrocytes was demonstrated by isotope release and release of hemoglobin. The cytotoxic effect was dependent on the contact between viable, activated macrophages and target cells. Activation was accomplished by prolonged cultivation of macrophages and by the presence of Zn++ and Con-A. Immunization did not prove necessary. Morphological observations as well as experiments with various salt concentrations indicate that the cytotoxic reaction may involve some kind of osmotic effect upon the target cells.


1990 ◽  
Vol 172 (6) ◽  
pp. 1853-1856 ◽  
Author(s):  
S Greenberg ◽  
K Burridge ◽  
S C Silverstein

We have studied the distribution of talin in J774 cells and mouse peritoneal macrophages undergoing Fc receptor-mediated phagocytosis. At early stages of phagocytosis, talin accumulates in the cells' cortical cytoplasm adjacent to the forming phagosome and extends into pseudopods that are encircling the particle. Talin colocalizes with F-actin at these sites. After particle ingestion is completed, F-actin and talin are no longer concentrated adjacent to phagosomes. Thus, talin and F-actin undergo dynamic and coordinate changes in their cytoplasmic location during Fc receptor-mediated phagocytosis.


1985 ◽  
Vol 30 (4) ◽  
pp. 373-380 ◽  
Author(s):  
V. Větvička ◽  
I. Miler ◽  
P. Šíma ◽  
L. Táborský ◽  
L. Fornůsbk

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