Reticulo-Endothelial Activity in Haemamoeba (=Plasmodium) gallinacea Infections

SYNOPSIS. The effect of H. gallinacea infection on the phagocytic activity of the reticulo-endothelial system in chicks has been investigated. Changes occurring in the pattern of R.E. activity show that there is initial stimulation of phagocytosis within 24 hr and that this increases up to the 4th and 5th days after which time parasites appear in the blood. Thereafter there is a rapid drop in R.E. activity with a proportional increase in parasitaemia following which death ensues. The importance of the protective value of the reticulo-endothelial system is indicated and it is suggested that a toxin produced by the parasites or by their break-down products is the likely cause of phagocytic depression.     

Effect of cefoperazone on the activity of selected parameters of cellular immunity in mice with experimental viral-bacterial infection

We applied mixed, viral-bacterial infections of mice (with influenza virus to the respiratory tract and Staphylococcus aureus) intereperitoneally. We used Sodium Cefoperazone subcutaneously in the dose of 30 mg/kg body weight 24, 48 and 72 hours after the infection. We evaluated phagocytic activity of the granulocytes isolated from animals and bactericidal activity of these cells expressed as their chemiluminescent activity. We studied it on the 3rd, 6th, 9th, and the 14th day after the infection. Phagocytic activity of cells taken from infected mice and treated with the preparation expressed as phagocytic index was the following: 0.38, 0.19; 0.88; 0.99 respectively. In the comparative studies, concerning the effect of preincubation of cells with antibiotic (at the concentration produced in blood serum by therapeutic doses) we found the increase in chemiluminescent process by 57% on the average. Analyzing the preliminary data form the experimental studies on the influence of Cefoperazone on mixed, viral-bacterial infections in mice we found the positive effect of the antibiotic evaluated in some immunological test. Intracellular killing of bacteria is stimulated. Preincubation of granulocytes with the antibiotic gives higher chemiluminescent activity of cells. However, chemotactic and phagocytic activity of cells are not changed.     

Relations between the changes of the phagocytic activity of the reticuloendothelial system and the alterations in protein and nucleic acids contents of the rat liver (author's transl)]

The phagocytic activity of the reticuloendothelial system (RES) was evaluated after a single oral administration of soya-bean oil to male rats (15 g/kg). 1. An emulsion of soya-bean oil administered to the rat by gastric intubation activated the phagocytosis of colloidal carbon; the stimulation appeared on the 2nd day after treatment and persisted up to the 3rd day. There was also a relation between the stimulation of RES activity, under our experimental conditions, and the increased level observed in the protein and nucleic acid contents of the liver. 2. In contrast, without emulsion, soya-bean oil depressed the phagocytic activity on the 2nd and 3rd days after administration of the oil. These changes were associated with a diminution in ribonucleic acid and protein contents of the liver. Although the mechanisms of soya-bean oil-induced alterations of phagocytic activity were not clarified, there was a relationship between the RES stimulation or inhibition and the modifications in nucleic acid and protein contents of rat liver.     

Effect of regional (wound) revaccination with tetanus anatoxin on the functional activity of immunocompetent cells in the region]

The study made with the use of complex methods established that the local (wound) application of tetanus toxoid rapidly made the manifestation of the lysosomal apparatus more pronounced, increased the oxidizing activity (determined in the nitro blue tetrazolium test) and phagocytic activity of the mononuclear phagocytizing system in the wound and in the regional lymph nodes. The wound application of tetanus toxoid significantly increased blast transformation of T lymphocytes in guinea pigs simultaneously with tetanus wound infection. The study confirmed the pathogenetic expediency of the proposed method for the stimulation of anti-tetanus immunity by the application of tetanus toxoid on the wound which specifically inhibited the primary stage of the infectious process.     

Plasmodium berghei: Phagocytic activity in two strains of rats

The Wistar and Sprague-Dawley strains of rats differ in their ability to maintain phagocytic hyperactivity toward colloidal carbon during infection with Plasmodium berghei. Both strains were highly stimulated by the 4th day, but on the 7th and 8th days of infection one-third of the Sprague-Dawley rats were not hyperactive while all the Wistar rats remained hyperactive. The course of infection subsequent to the carbon test was similar in hyperactive and in nonhyperactive rats.     

Effect of antibiotic therapy and vaccine therapy on the phagocytic reaction in mice infected with Staphylococcus

The time course of changes in the activity, intensity and completeness of phagocytosis with leukocytes of the peritoneal exudate was studied on mice with experimental staphylococcal infection treated with rifampicin, lincomycin and inactivated staphylococcal vaccine used alone or in combination. It was shown that immunization of the animals with inactivated staphylococcal vaccine promoted stimulation of the phagocytic defense. Rifampicin and lincomycin applied therapeutically induced a decrease in the activity, intensity and completeness of phagocytosis. It should be noted that rifampicin had a less pronounced inhibitory effect than lincomycin. The combined use of vaccine and antibiotics with therapeutic purposes promoted an increase in phagocytosis as compared to the use of the antibiotics alone. The combined therapy sometimes resulted in completeness of phagocytosis making it reach the control values (the 10th and 15th days, rifampicin and vaccine). It should be noted that a more pronounced stimulation of the activity, intensity and completeness of the phagocytosis was observed with the use of the combination of rifampicin and the vaccine.     

The effect of Mycoplasma arthritidis infection on the kinetics of colloidal carbon clearance in mice

Abstract The activity of phagocytes from A/J mice was estimated by the carbon clearance test following injection of Mycoplasma arthritidis . Phagocytic activity was significantly depressed 12 h post-infection ( P =0.001) and returned to normal values at 24 h. For animals examined 2 and 7 days post-infection, the overall phagocytic activity increased significantly ( P <10⁻⁴). Phagocytic activity gradually decreased and returned to that of the control group by the end of the fourth week. The relative weights of liver and spleen were significantly increased from the 2nd day post infection ( P =0.0028 and P =0.0014 respectively) and remained increased until the end of the experiment. The early depressive effect on phagocytic activity may be related to superantigen activity with the production of mediators such as macrophage deactivating factor. The later expansion of the macrophage population might bring about the stimulation of autoreactive clones of T and B cells and be responsible for the chronic arthritis that developed in the mycoplasma treated mice.     

Macrophage activation in the immune response

In inbred white rats, immunized with sheep erythrocytes, contents and phagocytic activity of the spleen and pulmonary macrophages have been studied on the 3d, 4th, 5th, 6th, 7th, 11th, 14th and 20th days of the experiment in the light, scanning and transmissive electron microscope, as well as the effect of the cells mentioned on proliferation of lymphoid elements. Maximal phagocytic activity of the splenic and alveolar macrophages is observed on the 7th day of the experiment. At the same time, certain drop in the lymphoid cells proliferation takes place. The change in the macrophages contents also influences proliferation of the lymphoid cells.     

Oxidative and phagocytic functions of macrophages during infections induced in mice by Mycobacterium intracellulare and Listeria monocytogenes

The oxidative metabolism (chemiluminescence and H2O2 release) and phagocytic activity of mouse peritoneal macrophages during chronic infections induced by Mycobacterium intracellulare and more acute infections due to Listeria monocytogenes were studied. In M. intracellulare infections, macrophage chemiluminescence in response to phorbol myristate acetate (PMA) was greatest at around 2 weeks, with a 1 week lag phase after infection, while the PMA-triggered H2O2 release was markedly enhanced even 1 d after challenge, and remained high thereafter for up to 10 weeks. The pattern of changes in the phagocytic activity of host macrophages in response to latex beads during this infection resembled the pattern seen with macrophage H2O2 release. In the L. monocytogenes infections, the PMA-triggered chemiluminescence of the host macrophages increased 4 d (in a sublethal infection) and 2 d (in a lethal infection) after bacterial challenge, whereas the PMA-triggered H2O2 release was markedly enhanced as early as 1 d after infection and the elevated level persisted until either the bacteria were eliminated or the animals died. The patterns of changes in phagocytic activity of the host macrophages during L. monocytogenes infection at sublethal and lethal doses differed. In the former, phagocytosis was most active in the early phase of infection, with a peak around day 2, followed by a rapid decrease; in the latter, the phagocytic ability increased more slowly, and remained elevated until the animals died. The results suggest that the macrophages induced by M. intracellulare are in a more activated state than are those induced by L. monocytogenes.     

Phagocytic capacity of Kupffer cells during hepatic amoebiasis in guinea pigs.

Very few studies have been carried out on the role of liver macrophages (Kupffer cells) during the course of hepatic amoebiasis. The kinetics of phagocytic activity of Kupffer cells and blood monocytes was studied in guinea pigs intra-mesenterically infested with Entamoeba histolytica. The phagocytic capacity of blood monocytes of normal animals was comparatively lower than Kupffer cells for both latex and haemolysin coated sheep red blood cells. Significant decline in phagocytic response of Kupffer cells and blood monocytes of infected animals was observed right from 2nd post infection day and it kept on decreasing with the progress of infection. Depression in phagocytic response of Kupffer cells and blood monocytes was more marked in those animals who had higher grades of pathological lesions. Hence, an inverse correlation was obtained between the phagocytic capacity and severity of amoebic lesions (P less than 0.01). The significance of depression in phagocytic response of Kupffer cells and blood monocytes may be responsible for the development of hepatic lesions.     

Effects of dietary β-1,3-glucan, chitosan or raffinose on the growth, innate immunity and resistance of koi (Cyprinus carpio koi)

This study was performed to determine the efficacy of three immunomodulators viz., β-1,3 glucan, chitosan and raffinose on the innate immune response of koi, Cyprinus carpio koi. Kois were divided into 4 groups and each group was fed with diets supplemented with or without immunostimulant for 56 days. Total leukocyte counts (WBC), the non-specific humoral (lysozyme, alternative complement pathway and superoxide dismutase) and cellular (phagocytic capacity and respiratory burst activity) responses were determined and compared with controls (no supplement) after 7, 14, 21 and 56 days of feeding. The results of 8 weeks feeding trial showed that β-1,3 glucan supplementation significantly enhanced koi growth, whereas other immunostimulants did not. Variation in the levels of responses was?evident among different supplements. Compared with chitosan or raffinose, β-1,3 glucan could maintain the immunity of kois at a higher level during the experimental period. However, continuously applying β-1,3 glucan, chitosan or raffinose into the diet caused immunity fatigue in koi. No significant change in alternative complement pathway (ACP) activity was observed for any of the three supplements over the four different periods. After feeding for 14 days, the total leukocyte count (WBC), respiratory burst activity and superoxide dismutase (SOD) activity of the kois fed with chitosan or raffinose continuously remained relatively unchanged, subsequently decreased on the 56th day, but SOD did not. Meanwhile, lysozyme activity was no longer significantly higher on the 7th day, and for phagocytic capacity on the?14th day. After 56 days, these three immunostimulants groups also exhibited a decrease in the cumulative symptom rates compared to the controls when challenged with Aeromonas veronii. These results indicated that dietary intake containing immunostimulants could enhance the immune responses of koi and improve its resistance to infection by A.veronii. Especially supplementation with β-1,3 glucan to the kois for 56 days showed considerable improvement in the growth, survival and immune response of the kois.     

Changes in the leukocyte phagocytic activity of donor blood after its UV irradiation. I. Its relation to the irradiation dose and initial level of phagocytic activity

Phagocytic activity of human mono- and granulocytes increased markedly after UV blood irradiation in the apparatus "Izolda" used in hospitals of the USSR for medical treatment. With the rise of irradiation dose the ratio of cells ingesting latex particles increased, although the average number of particles ingested per cell decreased. The integrative phagocytic index poorly depended on the irradiation dose. In patients with a low initial level of phagocytic index, after UV blood irradiation it became more pronounced than in those with the initial elevated level. The enhancement of phagocytic activity is the result of a direct UV-stimulation of cells. This stimulation not mediated by irradiated blood plasma is known to inhibit the phagocytic activity of leucocytes. A possible mechanism of phagocytic activity stimulation is discussed.     

Effect of bacterial endotoxin on the phagocytic activity of the reticulo-endothelial system in rabbits of different age

Stimulation of the phagocytic activity of the reticulo-endothelial system with bacterial endotoxin was studied in newborn rabbits in the period in which they do not actively form antibodies to bacterial antigens. A markedly accelerated clearance of colloidal carbon from the blood was found in five-day-old rabbits (tested by the technique of Biozzi, Benacerraf and Halpern 1953) when relatively high doses of endotoxin were used. It is assumed that the increased resistance to infection which may be elicited in young animals in that period is due to stimulation of cellular defence mechanisms. By comparison of the stimulating effect of endotoxin on phagocytosis in five-day-old, one-month-old and adult rabbits it was found that the phagocytic cells of the R.E.S. are more susceptible to the effect of endotoxin in adults than in newborns. This difference is evident from comparisons of the phagocytic indices K and the corrected phagocytic indices α in three age groups of rabbits stimulated with different doses of endotoxin. The possible mechanism and cause of differences in sensitivity of young and adult individuals is discussed.     

Infradian rhythmicity in milk leukocyte activity together with plasma cortisol and prolactin levels throughout the lactation period in high-yielding crossbred cows

Infradian rhythmicity in milk leukocyte activity together with plasma cortisol and prolactin levels throughout the lactation period in high-yielding crossbred cows has been studied in 10 high-yielding (milk production: 5000 l per lactation) Karan Fries crossbred (Holstein Friesian × Tharparkar) cows. Milk and blood samples were collected from all the experimental animals. Isolation of milk phagocytes (neutrophils and macrophages) and lymphocytes were done by density gradient centrifugation. In vitro phagocytic index of milk neutrophils and macrophages was performed by colorimetric NBT reductive assay. Mitogen-induced milk lymphocyte blastogenic response was estimated by colorimetric MTT (tetrazolium) assay. Total plasma cortisol and prolactin were estimated by enzyme immune assay. Highest value of plasma cortisol and prolactin was observed at calving which decreased significantly (p < 0.01) on 15th day postpartum for both prolactin and cortisol. Immune activity of milk leukocytes was highest on day 0 colostrum and decreased significantly (p < 0.01) on 7th day postpartum. A significant (p < 0.01) rise of plasma prolactin was observed around 135th and 225th days postpartum, whereas a peak level of plasma cortisol was observed at 105th, 180^th, and 270th days postpartum. Phagocytic index of milk neutrophils and macrophages remains almost in a steady state during mid-lactation period (between 100 and 200 days postpartum). A decline in increasing trend of milk phagocytic activity was observed during late lactation. Mitogen-induced milk lymphocyte blastogenic response was highest on day 0 colostrum which decreased significantly (p < 0.01) on 15th day postpartum. Con A-induced milk lymphocyte blastogenic response showed an increasing trend from 120th to 210th days postpartum. Upon correlation study, it showed that the plasma cortisol has a negative effect on milk leukocyte activity, while prolactin has a positive effect, though the effect is lactation stage specific.     

Elevated anti-parasitic activity in peripheral blood monocytes and neutrophils of cattle infected with Babesia bovis

The innate immune response to bovine Babesia bovis infection in vivo has not previously been established. We used assays measuring phagocytosis and oxidative burst to investigate the immune response because they are indicative of the innate antimicrobial capacity of monocytes and neutrophils. Monocyte and neutrophil phagocytosis is thought to be non-specific in nature and so the phagocytosis of either opsonised Zymosan or Escherichia coli was used to indicate the non-specific phagocytic capacity of monocytes and neutrophils ex vivo. The kinetics of both phagocytic and oxidative burst activity in monocytes and neutrophils were followed twice weekly from pre-inoculation (day 0) through to 31 days after inoculation. Peripheral blood monocytes were found to display a pronounced oxidative burst, but a suppressed capacity to phagocytose during a primary infection. On the other hand, neutrophils exhibited an increased phagocytic capacity and reduced oxidative activity during a primary infection. These findings identified considerable antimicrobial activity evident in peripheral blood monocytes and neutrophils from cattle exposed to B. bovis as a primary exposure. This elevated antimicrobial activity was coincident with the time that parasite numbers peaked in the circulation and occurred prior to parasite clearance. These results suggest that peripheral blood monocytes and neutrophils are active mediators in the innate immune response to a primary B. bovis.     

A study of altered cytokine rhythms associated with successful implantation in cows

Implantation is a critical process wherein the dam accepts the semi-allogenic embryo, characterized by certain vital immunological changes involving certain factors and cytokines. The current study was undertaken in Sahiwal cows to analyze the changes in certain selective immunological components of the body during peri-implantation period. Post-insemination the study was performed for a period till day 40 and the plasma was used to estimate the levels of progesterone, interleukin 1β (IL-1β), IL-2, IL-4, IL-6, and leukemia inhibiting factor (LIF) using Bovine specific ELISA Test Kits. The phagocytic activity and mRNA expression of progesterone-induced blocking factor (PIBF) were also analyzed. It was observed that in pregnant cows, the expression of PIBF increased from day 16th onward and remained high throughout the study period whereas the phagocytic activity was higher in non-pregnant cows all through the study period. The IL-1β, IL-2, and IL-6 were significantly higher in non-pregnant cows from 16th to 18th day post-AI as compared to P cows. On the other hand, IL-4 and LIF showed a significantly higher concentration in pregnant cows during peri-implantation period. Hence, it can be concluded that early embryonic survival is dependent on interplay of certain critical immunological factors in the body.     

Comparative study of rosette and plaque formation in rats infected with Mycoplasma arthritidis and Acholeplasma laidlawii]

M. arthritidis suppresses rosette- and plaque-formation in rats infected with this strain of mycoplasma. On the 15th day the immune response was restored in the control and experimental groups of animals. In later stages a strong stimulation of RFC and PFC was recorded, which levelled on day 150. On the contrary, A. laidlawii stimulated RFC and PFC in all stages of infection. A relationship between the phenomena described and pathogenic properties of the mycoplasma is discussed.     

Studies towards the potential of poliovirus as a vector for the expression of HPV 16 virus-like-particles

In this study we tested the hypothesis that after administration of a single intraperitoneal dose of concanavalin A (Con-A) to mice, the proportion of neutrophils and macrophages in the peritoneal exudate and their phagocytic and candidacidal activities should change with time. The number of neutrophils in the peritoneal exudate was greatly increased 6 h after administration of Con-A, and those cells were able to kill both intracellular and extracellular yeast and germ tube forms of Candida albicans. Addition of catalase to the culture medium reduced the killing of C. albicans, suggesting that the candidacidal activity depended on the myeloperoxidase system. The survival of mice pretreated with Con-A and submitted to an inoculum of C. albicans 6 h afterwards was twice higher than that of controls, which suggests that neutrophils were able to clear the experimental infection. One day after the treatment, the population of neutrophils in the exudate was about 45%, but after 2 days it was reduced to only 5% and the candidacidal activity was also reduced. After 4 days the exudate contained over 95% of macrophages, the candidacidal activity reached a maximum, and the phagocytosis mediated by both complement receptors and mannose receptors was increased. Uptake of FITC-mannose-BSA by macrophages was maximal on about the 4th day and was inhibited by mannan, suggesting that treatment with Con-A increased the activity of mannose receptors. These results support the hypothesis that activation of cellular immunity by Con-A occurred in two phases, one dominated by neutrophils, and the other by macrophages expressing increased activity of mannose receptors.     

Study of rat pulmonary macrophages as affected by hydrocortisone administration and adrenalectomy

The blood clearance rate of inert colloidal particles and the number of rat lung interstitial phagocytic cells decrease considerably on the 7th day after daily subcutaneous hydrocortisone acetate (HC) injection at a dose of 125 mg/kg. The number of cells in the bronchoalveolar lavage (BAL) increases more than 5-fold, and the absolute quantity of neutrophils is 66 times higher than in the control. Phagocytic and microbicidal activity of HC-treated animal alveolar macrophages (AM) decreases. Stimulation with zymosan led only to the recovery of the normal parameters of mononuclear phagocytosis system (MPC) and its pulmonary compartment activity. The parameters of MPS and AM studied increase on the 7th day after bilateral adrenalectomy (AE). The number of BAL cell increases 1.4-fold due to the animals' death immediately after intravenous zymosan injection because of total hemorrhage. The data obtained testify to the influence of glucocorticoids on the composition and activity of bronchoalveolar space cells, which in turn determine the resistance of the lung tissue.     

NTPDase activity in lymphocytes of rats infected by Trypanosoma evansi

Trypanosoma evansi is the aetiological agent of trypanosomosis in domestic animals. In this pathology, an inflammatory response can be observed and, as a consequence, the increase of extracellular adenine nucleotides such as ATP. These nucleotide concentrations are regulated by ectoenzymes such as NTPDase (EC 3.6.1.5, CD39), which catalyses the hydrolysis of ATP and ADP into AMP. In this study, the activity of NTPDase in lymphocytes of rats experimentally infected with T. evansi was evaluated. The animals were inoculated with the parasite and monitored by blood smear on a daily basis. The animals were then were divided into 4 groups according to the degree of parasitaemia and period of infection. The blood collections for enzyme analysis and lymphocyte count were performed on the 3rd (beginning of infection), 5th (acute infection) and 15th (chronic infection) days post-infection (p.i.). The control group was composed of non-infected animals. In the infected group a decrease in ATP hydrolysis (36%) was observed on the 3rd day p.i. and a decrease in ADP hydrolysis (62%) was observed on the 5th day p.i. when compared to the control. On the 15th day p.i., an increase in ATP (94%) and ADP (50%) hydrolysis was observed in the infected group. Considering these data it is suggested that NTPDase activity is altered on the surface of lymphocytes of rats infected with T. evansi at different time-points of infection.