Methodologic approaches to assessing cellular protection in influenza (the model: splenocyte versus splenocyte)

To study the cell-mediated link of immune response in mice in experimental influenza, both spleen cells obtained from intact mice and infected with the virus in vitro and spleen cells obtained from infected mice on day 6 after infection may equally be used with success as target cells. This opens the possibility of studying the role of virus-specific modifications of the cell membranes of immunocytes in the pathogenesis of influenza infection. The use of effector cells without their additional stimulation with homologous virus in vitro permits the simultaneous study of different mechanisms of specific (cytotoxic T lymphocytes and antibody-dependent cell-mediated cytotoxicity) and nonspecific (natural killer cells) cell-mediated immunity developing in influenza, as well as the study of the functional activity of spleen cells under the conditions similar to those existing in the body when the duration of the experiment is 5-7 days shorter.     

大肠埃希菌感染小鼠外周血中性粒细胞与 淋巴细胞比值的动态变化

目的通过观察大肠埃希菌感染小鼠模型不同时间段外周血中,中性粒细胞与淋巴细胞比值的动态变化,分析外周血中中性粒细胞/淋巴细胞比值与大肠埃希菌感染炎症程度的关系,以及中性粒细胞与淋巴细胞在大肠埃希菌感染时的可能作用机制。方法将麦氏浊度为2.73约为1×109CFU/m L大肠埃希菌通过尾静脉注射建立ICR小鼠感染模型44只、空白对照4只及阴性对照4只。实验组按1、3、6、12、24、48、72、96、120、144和168 h,共11个时间段,每次取4只小鼠,抽取外周血800μL,利用SYSMEX2100检查白细胞总数、中性粒细胞计数、淋巴细胞计数、中性粒细胞/淋巴细胞比值变化情况。结果大肠埃希菌ICR小鼠感染组1~24 h白细胞总数比对照组降低(0.01P0.05),第2天时与对照组比较差异无统计学意义,第3天至第7天白细胞总数比对照组高且差异有统计学意义(P0.01),并在第7天时略有回落;感染组中性粒细胞计数值在感染12 h到第7天比对照组高,差异有统计学意义;中性粒细胞/淋巴细胞比值对照组为0.06±0.03,感染1 h为0.07±0.04,与对照组比较差异无统计学意义(P0.05),3 h、6 h两组与对照组比较差异有统计学意义(0.01P0.05),12 h开始到第7天感染组与对照组比较差异有统计学意义,且第7天时为最高值(1.52±0.38)。结论中性粒细胞/淋巴细胞比值,比白细胞总数计数、中性粒细胞计数在大肠埃希ICR小鼠感染模型组中判断小鼠感染状况敏感,中性粒细胞/淋巴细胞比值结合白细胞总数计数、中性粒细胞计数能为临床大肠埃希菌感染的状况提供更灵敏的诊断参考数据,且易在临床推广。     

Inhibitory role of neutrophils on influenza virus multiplication in the lungs of mice.

The protective role of neutrophils on intranasal infection of influenza virus was investigated in 3 strains of tumor-bearing mice with neutrophilic leukocytosis. In vitro multiplication of influenza virus was inhibited by neutrophils from both normal and tumor-bearing mice, and the inhibitory effect of neutrophils was augmented by an addition of fMLP to the culture. Pulmonary virus infectivities in the early phase after infection decreased in such ICR and BALB/c mice, and virus elimination in the late phase was accelerated in the ICR mice. However, no decrease in pulmonary virus infectivity was observed in tumor-bearing C57BL/6 mice. Intranasal administration of fMLP into normal and tumor-bearing C57BL/6 mice after infection significantly inhibited the virus propagation in the lungs. The decrease in neutrophil infiltration into the lung in tumor-bearing C57BL/6 mice was confirmed from histological observations of the lung and lung lavage after infection and from analysis of the neutrophil chemotactic activity induced by fMLP. This might be responsible for the high level of pulmonary virus titer in tumor-bearing C57BL/6 mice. Phagocytic activities of alveolar macrophages and productions of neutralizing antibody were suppressed in the 3 strains of tumor-bearing mice. These observations indicated that neutrophils could be significant effector cells as a host defense mechanism against influenza virus infection in vivo, and infiltration and functional activation of neutrophils could play a significant role in virus elimination from the infected site. Furthermore, the inhibition of virus propagation by neutrophils in vitro was almost completely abrogated by an addition of ZnSO4, suggesting that calprotectin could inhibit influenza virus multiplication.     

Natural killer cells vs cytotoxic T cells in the peripheral blood of virus-infected mice

The cell-mediated immune response of mice against various enveloped RNA and DNA viruses expressed by immune lymphocytes from the spleen and the peripheral blood (PBL) were compared. PBL from mice of various strains infected with vaccinia virus, vesicular stomatitis virus (VSV), or lymphocytic choriomeningitis virus (LCMV) were tested on histocompatible or incompatible target cells infected with the homologous virus. PBL from immune mice showed clear H-2 restriction, but additionally, they expressed high natural killing (NK) activity on YAC-1 cells. The high NK-cytolytic activity of PBL on YAC-1 differed significantly from that expressed by splenic lymphocytes. In both lymphocyte populations lysis was detected as early as 1 day after infection; NK activity decreased in the spleen after day 4 post infection, whereas that of PBL persisted at high levels for up to 10 days after infection. Treatment of mice with anti-asialo GM1 in vivo abrogated NK activity in PBL effector cells tested in vitro. These results may explain some of the difficulties to observe MHC-restricted cytotoxic T cells in PBL from humans or primates during primary infections with virus.     

In vivo administration of anti-asialo-GM1 antibody enhances splenic clearance of Listeria monocytogenes

Resistance of mice to infection by Listeria monocytogenes involves a biphasic response. The first phase consists of the first 48 h after infection, during which there is multiplication of Listeria in the liver and spleen of infected mice. In these nonimmune mice, macrophages and polymorphonuclear leukocytes are the effector cells involved in controlling multiplication. In the second phase, cell-mediated immunity develops, beginning on day 2, during which multiplication of Listeria is prevented by macrophages possessing increased microbicidal activity that is mediated through the action of lymphokines released by immunologically committed T lymphocytes. The purpose of the present study was to define a role for natural killer (NK) cells in natural resistance to Listeria during the first 48 h after infection, prior to the development of specific immunity. Splenic NK cell activity was enhanced following a sublethal intravenous injection of viable Listeria as early as 24 h after injection and remained elevated throughout the nonimmune phase of infection. Interestingly, treatment of mice with anti-asialo-GM1 significantly enhanced the ability of mice to clear Listeria from the spleen relative to infected controls possessing intact NK cell populations. This was evidenced by 23-fold fewer bacteria obtained from the spleens of anti-asialo-GM1-treated mice. In addition, Percoll-enriched NK cell populations obtained from 48-hour Listeria-infected mice do not exhibit in vitro listericidal activity. These observations suggest a regulatory role of NK cells in resistance against Listeria and preclude a role for NK cells in direct cytolysis. Perhaps these cells modulate the immune response to Listeria by down-regulating the activity of the immune cells crucial to listerial resistance.     

The correction of the functional activity of alveolar macrophages in inducing a primary immune response in influenza]

The functional activity of alveolar macrophages obtained from mice, both healthy and infected with influenza virus A/Aichi 2/68 (H3N2), as manifested by their capacity to initiate the development of primary immune response to sheep red blood cells and Escherichia coli lipopolysaccharide after the transfer of these macrophages to intact syngeneic recipients was studied. The capacity of alveolar macrophages to perform antigen-presenting functions in the induction of humoral immune response was shown, and at the same time the development of experimental influenza infection was found to essentially decrease these properties. The injection of the immunomodulating agent diuciphon into experimental mice somewhat enhanced the immune response after the syngeneic transfer of alveolar macrophages from infected mice to intact recipients.     

Natural killer cell activity in mice infected with Acanthamoeba culbertsoni]

The natural killer cell activity of splenocytes and TBC, active NK cells, recycling capacity of natural killer cells were observed by means of both the 51Cr-release cytotoxicity assay and single cell cytotoxicity assay against YAC-1. C3H/HeJ mice were infected intranasally with 1 x 10(4) or 1 x 10(5) trophozoites of pathogenic Acanthamoeba culbertsoni. The infected mice showed mortality rate of 34% in 1 x 10(4) group and 65% in 1 x 10(5) group, and mean survival time was 16.40 +/- 3.50 and 13.20 +/- 4.09 days respectively. The cytotoxic activity of natural killer cells of the 2 groups was significantly higher than that of non-infected mice from the 12th hour to the 2nd day after infection, showing the highest on the first day. On the 10th day after infection, the cytotoxic activity of natural killer cells was significantly suppressed as compared with that of the control. There was no significant difference in NK cell cytotoxicity between two infected groups. The target-binding capacity and active NK cells of natural killer cells in 1 x 10(5) trophozoite infected mice was significantly increased on the 12th hour and the first day after infection as compared with the control group. Maximal recycling capacity (MRC) was not changed during the observation period. The present results indicated that the elevation of natural killer cell activity in the mice infected with A. culbertsoni was due to elevation of target-binding capacity and increased active NK cells of natural killer cells, and not due to the maximal recycling capacity of the individual NK cell, and there was no difference between two experimental dose groups.     

Natural killer cell activity in Naegleria fowleri infected mice]

The natural killer (NK) cell activity of splenocytes and recycling capacity of NK cells were observed by combining the 51Cr-release cytotoxicity assay and single cell cytotoxicity assay against YAC-1. The ICR mice were infected intranasally with Naegleria fowleri, that is a pathogenic free-living amoeba. The mice infected with 1 x 10(5) trophozoites showed mortality rate of 76.7% and mean survival time of 12.9 days. The cytotoxic activity of NK cells in infected mice was significantly higher than that of non-infected mice during the period between 12 hours and day 3 after infection, and highest on day 1. The target-binding capacity of NK cells in infected mice was not different from that of non-infected ones. Maximal killing potential and maximal recycling capacity were remarkably increased in infected mice as compared with the control. The results obtained in this observation indicated that elevated NK cell activity in mice infected with N. fowleri was not due to target-binding capacity of NK cells but due to the increased activity of NK cells and increased recycling capacity of individual NK cells.     

The effect of salmonella infection on the functional activity of the polymorphonuclear leukocytes]

Experiments on noninbred white mice have revealed that in the animals infected with S. moscow secondary immunodeficiency develops, which is manifested by a significant decrease in the activity of the bactericidal system of peripheral blood granular leukocytes. Simultaneously, the content of myeloperoxidase in the blood neutrophils of infected mice decreases 1.4 times and the content of lysozyme in these neutrophils decreases 2 times. Such changes are the consequence of an increase in the secretory activity of cells, occurring in the process of the development of Salmonella infection.     

Immunological and pathological aspects of respiratory tract infection with Stenotrophomonas maltophilia in BALB/c mice

A comprehensive study on the production of inflammatory mediators in the lungs of BALB/c mice following infection with Stenotrophomonas maltophilia was conducted. The levels of pro-inflammatory cytokines, tumor necrosis factor alpha (TNF-alpha) and Interleukin-1beta (IL-1 beta) was raised in the lungs of infected mice compared to control. The production of anti-inflammatory cytokine IL-10 was slightly delayed. Its peak level was on 2nd day whereas the peak of pro-inflammatory cytokines was observed on day one after intranasal challenge. This was accompanied with a rise in Myeloperoxidase (MPO) and Malondialdehyde (MDA) on day one. The increase in MPO levels matched with histopathological observations as neutrophils infiltration was detected on the first day. Alveolar macrophages (AMs) obtained from infected animals showed higher rate of uptake and killing when exposed to bacteria in vitro compared to similar experiment conducted with AMs from normal mice (control). This suggests that AMs were more efficient in cleaning the bacteria. The nitric oxide (NO) production though started early during infection but reached its maximum on 3rd day. No mortality was observed among the infected animals and infection was resolved by 5th post infection day. No drastic changes in the lung tissue were observed on histopathological examination.     

Cell-mediated immunity in mice infected with Acanthamoeba culbertsoni

Observations were made on the differences of cell-mediated responses in mice of three infection groups differently scheduled in their severity with pathogenic Acanthamoeba culbertsoni. Infections were done by dropping 5 microliters saline suspension containing 3 x 10(3), 1 x 10(4), or 1 x 10(5) trophozoites, respectively. Amoebae were cultured axenically in CGV medium and inoculated into the right nasal cavity of C3H/HeJ mice aging around 6-8 weeks, under the anesthesia by intraperitoneal injection of secobarbital. Delayed type hypersensitivity (DTH) responses in footpad and blastogenic responses of mouse spleen cells using (3H)-thymidine and the serum antibody titer were measured up to day 14 after infection, and natural killer cell activities were measured up to day 5 after infection. The results obtained in this study were as follows: 1. The mice infected with 3 x 10(3) trophozoites showed mortality rate of 17%, and 34% in the mice infected with 1 x 10(4) trophozoites and 65% with 1 x 10(5) trophozoites. 2. In regard to DTH responses in all experimental groups, the level increased on day 7 and declined on day 14 after infection, but their differences could not be noted between infected and control groups. 3. The blastogenic responses of splenocytes treated with amoeba lysates and lipopolysaccharides (LPS) showed no difference from the control group. The blastogenic responses of splenocytes treated with concanavalin A were declined significantly in the experimental group as compared with the control group, but the blastogenic responses of splenocytes treated with polyinosinic acid were not different from the control group. There was also no difference among three infected groups. 4. The cytotoxic activity of the natural killer cells was activated on day 1 after infection and declined to the level of control group on day 2 in all experimental groups. On day 5 after infection, the natural killer cell cytotoxicity was significantly suppressed as compared with the control groups. 5. The serum antibody titers of the infected mice increased after day 7, but there was no statistical difference between the three infected groups. In summary of the results, there was no difference in cell-mediated immune responses of three experimental groups scheduled with different infection intensities. But there was a significant difference in cell-mediated immune responses between infected and control mice. It is considered that cell-mediated immune responses should be involved in murine model infected with A. culbertsoni.     

Immunohistological characterization of leukocytes in the lungs of healthy mice and after bacterial intratracheal infection

Leukocytes in the peripheral lung parenchyma of mice have not been characterized histologically during bacterial infection. The aim of this study was to investigate (a) the immunohistological characteristics of healthy murine lungs and (b) the cell kinetics during acute inflammation. BALB/c and MF1 mice were examined; as well as transgenic mice with the gene defect of cystic fibrosis (CF) in the airways as an animal model for this disease. MF1 mice served as controls for the transgenic animals. Lavaged and perfused lungs were snap frozen. B and T lymphocytes, CD4+ and CD8+ cells, dendritic cells, neutrophils and a subset of macrophages were enumerated on cryostat lung sections. The lung tissue and bronchoalveolar lavage (BAL) of BALB/c mice, infected intratracheally with Haemophilus influenzae type b (Hib), were studied at different time points after infection. In the lungs of healthy mice, including CF mice, the largest population was that of T cells, CD4+ cells being always more frequent than CD8+ cells. During acute inflammation the number of neutrophils in the lung parenchyma and BAL increased strongly within the first hours after bacterial instillation and reached baseline levels within one week. This study provides a semi-quantitative analysis of immunocompetent cells in normal and infected murine lung tissue. Differences in cell numbers are found between different strains. Moreover, the cellular reaction during Hib infection in mouse lungs is dominated by neutrophils, as expected in a primary immune response. In uninfected CF mice the numbers and distribution of immune cells in the lung tissue are normal, indicating that the cellular defense is adequate.     

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.     

The immune response to herpes simplex virus type 1 infection in susceptible mice is a major cause of central nervous system pathology resulting in fatal encephalitis

This study was undertaken to investigate possible immune mechanisms in fatal herpes simplex virus type 1 (HSV-1) encephalitis (HSE) after HSV-1 corneal inoculation. Susceptible 129S6 (129) but not resistant C57BL/6 (B6) mice developed intense focal inflammatory brain stem lesions of primarily F4/80(+) macrophages and Gr-1(+) neutrophils detectable by magnetic resonance imaging as early as day 6 postinfection (p.i.). Depletion of macrophages and neutrophils significantly enhanced the survival of infected 129 mice. Immunodeficient B6 (IL-7R(-/-) Kit(w41/w41)) mice lacking adaptive cells (B6-E mice) and transplanted with 129 bone marrow showed significantly accelerated fatal HSE compared to B6-E mice transplanted with B6 marrow or control nontransplanted B6-E mice. In contrast, there was no difference in ocular viral shedding in B6-E mice transplanted with 129 or B6 bone marrow. Acyclovir treatment of 129 mice beginning on day 4 p.i. (24 h after HSV-1 first reaches the brain stem) reduced nervous system viral titers to undetectable levels but did not alter brain stem inflammation or mortality. We conclude that fatal HSE in 129 mice results from widespread damage in the brain stem caused by destructive inflammatory responses initiated early in infection by massive infiltration of innate cells.     

Changes in the oxygen-dependent metabolic activity of polymorphonuclear leukocytes from the peripheral blood and macrophages from the peritoneal exudate in the experimental infection of mice with the causative agent of plague

The subcutaneous infection of C57BL/6J mice and noninbred white mice with 40 LD100 of Y. pestis virulent strain has been found to produce synchronous changes in the oxygen-dependent metabolism (ODM) of peripheral blood neutrophils in the spontaneous or zymosan-, E. coli- and Y. pestis-stimulated variants of the NBT test. These changes can be divided into three phases: (I) the phase of a sharp drop in ODM activity; (II) the phase of the increase of this activity, occurring simultaneously with the penetration of Y. pestis cells into the blood stream; and (III) the phase of the terminal decrease of ODM activity as the cytotoxic lesion of phagocytic cells occurs. Peritoneal exudate macrophages show a more gradual decrease in ODM activity. The infection of the animals with 40,000 LD100 of Y. pestis has been found to produce an increase in the ODM activity of neutrophils, rapidly followed by its decrease to the zero level. Macrophages show phasic changes in their ODM activity, identical to changes in the ODM values of neutrophils in mice infected with 40 LD100 of Y. pestis.     

Generation of cytotoxic T lymphocytes during coxsackievirus B-3 infection. I. Model and viral specificity1.

The production of cytotoxic cells in the spleen of adult male BALB/c mice infected with Coxsackievirus B-3 has been examined.An in vitro 51Cr release assay was used to measure cytotoxic activity against virus-infected and uninfected neonatal sygeneic fibroblasts. Cytotoxicity of immune spleen cells against virus-infected targets was detected on the 3rd day after infection, reached a peak on day 7, and then declined to low levels by days 12 and 14. Spleen cells obtained 3 and 5 days after infection also exerted cytotoxicity against uninfected fibroblasts, but by the 7th day there was little or no reactivity against uninfected target cells, although activity against infected fibroblasts was maximal at this time. Reciprocal assays performed by using Coxsackie and vaccinia viruses provided evidence of virus specificity of the cytotoxic reaction. When spleen cells were obtained 7 days after infection, the Coxsackievirus-immune population was not cytotoxic for vaccinia-infected fibroblasts, and the vaccinia-immune population was not cytotoxic for Coxsackievirus-infected targets, although each immune cell preparation caused significant lysis of fibroblasts infected with the homologous virus. Additional studies showed that primary mouse or hyperimmune rabbit anti-Coxsackieviral serum could not block immune spleen cell cytotoxicity or induce complement-mediated lysis of infected targets. The findings indicate that Coxsackievirus infection results in surface membrane alterations, but no evidence was obtained that antiviral antibody could react with the infected cells.     

Neutrophils activate macrophages for intracellular killing of Leishmania major through recruitment of TLR4 by neutrophil elastase

We investigated the role of neutrophil elastase (NE) in interactions between murine inflammatory neutrophils and macrophages infected with the parasite Leishmania major. A blocker peptide specific for NE prevented the neutrophils from inducing microbicidal activity in macrophages. Inflammatory neutrophils from mutant pallid mice were defective in the spontaneous release of NE, failed to induce microbicidal activity in wild-type macrophages, and failed to reduce parasite loads upon transfer in vivo. Conversely, purified NE activated macrophages and induced microbicidal activity dependent on secretion of TNF-alpha. Induction of macrophage microbicidal activity by either neutrophils or purified NE required TLR4 expression by macrophages. Injection of purified NE shortly after infection in vivo reduced the burden of L. major in draining lymph nodes of TLR4-sufficient, but not TLR4-deficient mice. These results indicate that NE plays a previously unrecognized protective role in host responses to L. major infection.     

Nitric oxide produced in Peyer's patches exhibits antiapoptotic activity contributing to an antimicrobial effect in murine salmonellosis

Salmonella species normally infect hosts via the oral-fecal route. We previously reported that NO had potent host defense functions in murine salmonellosis, not only via a direct antibacterial effect but also because it was cytoprotective for infected host cells. Here, we used an oral route to infect iNOS-deficient mice infected with S. enterica serovar Typhimurium to further investigate the cytoprotective role of NO in preventing damage caused by Salmonella organisms in PP. Oral bacterial challenge (2 x 10(5) CFU, or >100 LD(50)) produced a more severe infection and greater lethality in iNOS-deficient mice than in iNOS-competent mice. We used specific antibodies to S. enterica Typhimurium, neutrophils, iNOS, nitrotyrosine, and dendritic cells (CD11c-positive) in histochemical and immunohistochemical studies to examine infected PP tissues. S. enterica Typhimurium colonization in PP from iNOS-deficient mice was significantly higher than that in wild-type mice. Histochemical assays showed extensive cellular damage in PP. We then examined PP tissues for apoptosis by means of in situ TUNEL analysis and by measuring caspase-3 specific activity in tissue homogenates. Increased numbers of TUNEL-positive cells and severe granulomatous inflammation with increased infiltration of neutrophils and macrophages were observed during infection in iNOS-deficient mice compared with wild-type mice. iNOS-deficient mice had increased numbers of dendritic cells and significantly higher caspase-3-specific activity in PP. These data confirm that NO exerts its protective function not only through direct antibacterial action, but also by preventing apoptosis and thereby contributing to antimicrobial defense during salmonellosis.     

Characterization of the pattern of inflammatory cell influx and cytokine production during the murine host response to Listeria monocytogenes

To examine the physiologic mechanisms responsible for enhanced antibacterial activity during infection with Listeria monocytogenes (LM), we developed an in vitro assay for quantifying leukocyte anti-listerial activity (LAA) in spleen and bone marrow. When LAA was serially measured in C57B1/6 (B6) mice infected i.v. with LM, two distinct phases of response were observed. Splenic LAA increased four- to fivefold during the first 2 days after i.v. infusion of LM (from 2.4 +/- 1.8 U/spleen before infection to 11.8 +/- 2.4, p less than 0.01), dropped significantly on days 3 to 4, and increased again to similar levels from days 5 to 7. A fall in bone marrow activity from the 3.5 +/- 1.5 to 1.6 +/- 0.7 U/mouse (two femurs) coincided with the initial rise in splenocyte activity, and was followed by a gradual return to base line. Bacterial containment in vivo correlated well with splenic LAA in vitro. Carbonyl iron pretreatment of cells from both normal and LM-infected animals ablated LAA, suggesting the effectors were phagocytic. LAA in normal spleens was unaffected by 400 rad; LAA of normal marrow as well as splenocyte and marrow cell suspensions obtained 2 days after LM infection was markedly reduced by this dose of irradiation. Quantitative studies of spleen composition revealed a 10-fold increase in polymorphonuclear neutrophils between day 0 and day 2 followed by a marked decrease on day 3; this pattern closely resembled the changes in LAA observed during the same period. In contrast, splenic macrophage number did not increase from base line until after day 3. To look for evidence of changes in the efficiency of bacterial killing by phagocytes during infection, we calculated LAA/splenic phagocyte. The efficiency of killing increased threefold over base line within 1 day after LM infusion but we detected no additional increases later in infection. Because cytokines may have mediated some or all of the changes observed, we measured the capacity of splenocytes obtained at various times after infection to produce IL-2, TNF, and IFN-gamma in vitro. TNF activity increased in parallel with the first and second LAA peaks, whereas increases in IL-2 and IFN-gamma activity were associated only with the second.(ABSTRACT TRUNCATED AT 400 WORDS)     

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.