Attachment of Trypanosoma brucei to rabbit peritoneal exudate cells

Attachment of trypanosomes to cultured rabbit peritoneal cells was enhanced in the presence of hyperimmune Trypanosoma brucei antiserum and sera from infected rabbits. During infection attachment rose rapidly from control levels reaching a maximum value after two or three weeks; this was maintained until the death of the animal. The initial rise in activity was preceded by an increase in the serum titres of trypanosome agglutinating antibody. Attachment did not appear to be mediated by variant specific antibodies, no association being found between adherence and the appearance of successive variant subpopulations. Fractionation of hyperimmune and immune sera indicated that the majority of activity was present in the gamma globulin fraction with less activity in the macroglobulin fraction, despite its elevation during infection. Increased activity obtained with partially-purified immunoglobulin G prepared from hyperimmune serum was reduced following absorption with either disrupted or live trypanosomes.     

In situ fixation of cultured mouse peritoneal exudate cells: Comparison of fixation methods

Summary Mouse peritoneal exudate cells grown in vitro on plastic petri dishes were fixed in situ with both glutaraldehyde and osmium tetroxide by a variety of contemporary methods. The goal of the investigation was to determine which method resulted in the best ultrastructural preservation. The parameters being tested included: (a) the method of fixation, i.e. either sequential or simultaneous; (b) the buffer vehicle for fixation, i.e. cocodylate, Mellonig's phosphate, Sorenson's phosphate, ors-collidine; and (c) the temperature of fixation. Results presented indicate that simultaneous fixation is far superior to sequential methods. Samples fixed sequentially at 4° C consistently had better morphological preservation than samples fixed under similar conditions at 23° C. With the exception ofs-collidine, which was totally unacceptable for in vitro in situ fixation on plastic, comparable results were noted with different buffer vehicles. Previous reports by Cohn and coworkers (1–3) have established that adherent peritoneal exudate cells (PEC) are monocytoid, i.e. macrophages. Thus, in this report, the term adherent peritoneal exudate cells will be used synonymously with macrophages. Supported by a grant from the U.S. Veterans Administration entitled “A Comparative Study of Normal and Activated Macrophages.”     

Immune ascites in the guinea pig: specificity of cells and antibody in an induced peritoneal exudate.

Strain 2 guinea pigs, immunized with Lys10-Lys(Dnp) in CFA and repeatedly injected intraperitoneally with adjuvant, developed ascites. The fluid was harvested over 8 months in total amounts up to 2 liters per animal and contained substantial amounts of cells and antibody which reacted with the immunizing antigen and related peptides. The antibody was of the IgG and IgA classes and showed restricted heterogeneity. Among synthetic Dnp-oligopeptides, both the cells, studied by antigen-stimulated thymidine incorporation, and the purified antibody, studied by fluorescence quenching, demonstrated the same specificity for the immunizing antigen as has previously been noted in lymph node cells and in serum antibody. The technique offers a means for studying more cells and more antibody than has previously been possible from individual guinea pigs.     

Glycogen synthesis in resident and thioglycollate-elicited rat peritoneal exudate cells

The values of the A0.5 for glucose-6-P, apparent Km for UDPglucose and -/+glucose-6-P activity ratio are similar for glycogen synthase derived from rat resident and thioglycollate-elicited peritoneal macrophages; the specific activity is 7-fold higher for the enzyme from thioglycollate-elicited macrophages. The rate of incorporation of [14C]glucose into macrophage glycogen is 7-fold greater in the elicited population that that in the resident one; the values of the S0.5 for glucose are similar. The in vitro activation of glycogen synthase proceeds at a greater rate and extent for the enzyme from elicited macrophages; thus, phosphatase activity may be reduced in resident macrophages relative to that in thioglycollate-elicited ones.     

Inhibition of the mixed lymphocyte culture by peritoneal exudate cells.

Inhibition of mixed lymphocyte cultures (MLC) by macrophages and by supernatants of short term cultured macrophages was assessed by incorporation of ³H-thymidine (TdRH3) and also by blast cell counts and by determination of cellmediated lympholysis. Peritoneal exudate cells (PEC) induced by thioglycollate, at concentrations >10%, inhibited all three parameters of MLC. Lower concentrations of PEC, and supernatants from cultured PEC, inhibited TdRH3 incorporation, but had no significant effect on blast cell counts or on generation of cytotoxic effector cells. Inhibition by the supernatants could be reversed by dialysis or by use of low specific activity TdRH3. These data indicate that macrophages can inhibit proliferative responses in MLC, but that this must be carefully distinguished from selective inhibition of TdRH3 incorporation.     

Sodium-dependent and inhibitor-insensitive uptake of adenosine by mouse peritoneal exudate cells

[8-3H]Adenosine uptake in mouse peritoneal exudate cells, harvested following i.p. challenge with Complete Freund's Adjuvant from BALB/c mice, was found to be insensitive to common nucleoside transport inhibitors such as dilazep or 6-[(4-nitrobenzyl)mercapto]purine ribonucleoside and to require sodium ion, being inactive when sodium was replaced by lithium or potassium. These findings also applied to the adherent (macrophages) and nonadherent (polymorphonuclear cells) cell fractions prepared from the peritoneal cell mixture. Uptake was inhibited by several nucleosides including deoxyadenosine, inosine, uridine, thymidine and, to a lesser extent, by the adenosine analog tubercidin, while adenine, fructose, glucose and ribose were without effect. Uptake [8-3H]adenosine was fully matched by rapid intracellular phosphorylation to AMP, ADP and ATP. Inosine was a substrate for the transporter, but tubercidin was not. The system clearly is distinct from carrier-mediated, nonconcentrative transport and has similarities to concentrative, sodium-dependent nucleoside transporters described in other cell types.     

Action of low-frequency ultrasound on the peritoneum, peritoneal exudate cells and the course of experimental peritonitis

The authors studied the action of low-frequency ultrasound on rat and guinea-pig peritoneal exudate cells during aseptic peritonitis, on the intact peritoneum of these animals, and on experimental peritonitis in guinea-pigs. It was shown that ultrasound "hammers in" India ink solutions and antibacterial drugs into the peritoneum and in combination with antibiotics, it increases the guinea-pig survival rate in peritonitis. Ultrasound was not found to produce a direct bactericidal effect in vivo. Exposure of peritoneal exudate to ultrasound (1 s/cm2) demonstrated an increase in chemotaxis of neutrophil leukocytes to autologic serum and appreciable phagocytic activity. A longer exposure (up to 3-5 s/cm2 or 6-8 s/cm2) resulted in the partial damage to the peritoneum. Leukocytes, mesotheliocytes and subperitoneal striated muscles were found to be especially sensitive to ultrasound.     

Enhanced transfer of experimental allergic encephalomyelitis with strain 13 guinea pig lymph node cells: requirement for culture with specific antigen and allogeneic peritoneal exudate cells

Previously, we reported that transfer of experimental allergic encephalomyelitis (EAE) with sensitized peritoneal exudate cells (PEC) in strain 13 guinea pigs is markedly enhanced if the cells are first cultured with specific antigen, myelin basic protein (BP). These cells also undergo considerable antigen-specific proliferation. In contrast, the data reported here show that lymph node cells (LNC) from sensitized animals display neither enhanced transfer nor antigen-specific proliferation after culture with BP. Enhanced transfer is obtained, however, if a second nonspecific signal is available. This second signal is provided by the presence of normal allogeneic strain 2 PEC in culture. After culture with BP and strain 2 PEC, 2.5 to 5 x 10(7) strain 13 LNC transfer disease reproducibly, in contrast with approximately 1 x 10(9) previously required for successful transfer. Addition of allogeneic or syngeneic PEC without antigen does not lead to enhanced transfer by LNC. Culture with normal syngeneic PEC plus BP oly infrequently enhances transfer by LNC. The intense mixed lymphocyte reaction (MLR) induced by addition of strain 2 PEC to strain 13 LNC precludes the use of 3H-TdR incorporation for detection of proliferation by EAE effector cells. However, inhibition of transfer with low doses of mitomycin C (2 to 5 micrograms/ml) pluse the fact that EAE effector cells are found almost exclusively in the light fraction of BSA gradients after (but not before) culture suggests that the latter are induced to proliferate in culture.