Multiplication of meningopneumonitis organisms in white blood cells

Abstract

REPORTS on phagocytosis of viruses and the organisms of the psittacosislymphogranuloma-trachoma group are sporadic (Sabin, 1935 ; Florman and Enders, 1942; Merling, 1945).Observations of the fate of intracellular virus are comparatively more recent (Barski and Robbe-Fossat, 1957; Benedict and McFarland, 1958). The interaction of viruses with leucocytes has been shown to lead to (1) alteration in certain of the metabolic and phagocytic activities of the leucocytes (Merchant and Morgan, 1950; Fisher and Ginsberg, 1956), (2) agglutination of the leucocytes (Nungester, Gordon and Collins, 1950; Boand, Kempf and Hanson, 1957; Nishmi and Fkrnkopf, 1958; Shechmeister and Parikh, 1961 ; Parikh and Shechmeister, 1967), and (3) phagocytosis and multiplication of the virus (Dunne, Luedke and Hokanson, 1958; Parikh, Shechmeister and Yen, 1963). Smorodmtsev (1960), in reviewing the role of leucocytes in viral infections, stated that phagocytosis is not an important natural defence mechanism, except with the psittacosis-lymphogranuloma-trachoma group. However, the role of blood leucocytes, macrophages and other cells of the reticulo-endothelial system in the viral diseases has not been studied systematically. This is particularly true for phagocytosis of viruses by leucocytes in vitro and in vivo, which may explain in a relatively simple manner certain aspects of virus-host cell interaction.This report presents evidence for phagocytosis and multiplication of meningopneumonitis organisms (MP) in leucocytes (WBC) and stresses the importance of the MP:WBC ratio in determining the extent of intraleucocytic replication. MATERIALS AND hETHOD.5 Preparation of MP organismsProduction and concentration of MP suspensions. The Cal 10 strain of MP organisms, originally isolated by Francis and Magill (1938) was kindly supplied by Dr J. M. Moulder of the University of Chicago. The organisms were grown in the yolk sac of embryonated hen eggs by inoculating 0.5 ml. of a 1 in 100 dilution of the agent in each 5-to 6-day-old chick embryo and harvesting the yolk sac after 5 days' incubation at 37°C. No antibiotics were used, and freedom from bacterial contamination was determined by culturing in thioglycollate broth. Preliminary estimates of the concentration of MP were made by examination of smears of yolksac membrane stained with Macchiavello's stain. Infected yolk sac was ground in a homogeniser, or by mortar and pestle, in nutrient broth, the ratio of yolk-sac material to broth being 1 in 10, and then centrifuged at 4°C at 3020g for 30 min. Yolk-sac material and debris were discarded, and the supernatant was recentrifuged

Lysosomes and the "toxicity" of Rickettsials. II. Non-cytocidal interactions of egg-grown C. psittaci 6BC and in vitro macrophages

“…Our results also correspond with observations of others (7,25) on the absence of a CPE in mouse macrophages in vitro after infection with egg-grown Chlamydiae. The present observations support the suggestion of earlier authors (22) that chronically infected cells may be capable of surviving by releasing chlamydial elementary bodies from the cytoplasm and (or) by dissolution of the agent in cytoplasmic vesicles without concomitant cell destruction.…”

Lysosomes and the "toxicity" of Rickettsiales. I. Cytochemical studies of macrophages inoculated in vitro with C. psittaci 6BC

“…[16][17][18][19] plasmic granules" which represent lysosomes observed in the late stages of productive in- (12). fection of C. psittaci (36). It has been suggested Since the toxicity of C. psittaci for macro-that the stickiness or fusion of cells is due to an phages in vitro was not eliminated by heat, we alteration of their membranes caused by a cytowere interested in the effect of immune and lytic factor which might be similar or identical normal sera upon the toxicity of the agent in relation to the response of the macrophage's lysosomes.…”

“…Before the main experiments to be reported here, studies were carried out using 0.001 TCIDSO of the 6BC strain per mouse peritoneal macrophage, thus confirming that moderate doses of chlamydia1 agents multiply in white blood cells in vitro (9,36). Following this, and using the same moderate dosage of agent, the temporal relationships between the replication of the agent, the cytopathology, and the appearance of acid phosphatase positive (APO) structures were determined.…”

“…Cultured fibroblasts (L cells) used in our previous studies have the disadvantage of being quite dissimilar from highly specialized leucocytes that are involved in the in vivo reactions between microorganisms and the host; we have therefore carried out the present studies using mouse peritoneal macrophages in place of L cells so that the Chlamydiaehost cell interaction would more closely resemble the experiments used to define the "toxicity" of Rickettsiales in intact animals. Phagocytosis and m~~ltiplication of Chlamydiae in leucocytes in vivo and in vitro has been described (9,35,36). Increased resistance of ~nacrophages obtained from animals immunized to these agents has been demonstrated both in vivo and in vitro (9,35).…”