Phagocytic and bactericidal properties of macrophages of mice immunized with outer membrane proteins (OMP) of Shigella

Macrophages obtained from peritoneal exudates of mice immunized with the single doses (1 and 5 micrograms) of OMP were shown to have stronger phagocytic as well as bactericidal properties in relation to Shigella flexneri bacilli than nonactivated macrophages. Macrophages from the animals immunized with 10, 20 and 30 micrograms OMP doses showed phagocytic and bactericidal properties similar to those of nonactivated macrophages while the immunization with the dose 50 micrograms resulted in their suppression. Likewise, activity of macrophages from mice immunized twice or three times with various doses of OMP did not differ much from that obtained after immunization with single OMP doses. On the other hand, immunization of mice with a sublethal dose of live Shigella flexneri did not activate either phagocytic or bactericidal properties of macrophages. Besides, phagocytic and bactericidal activity of macrophages of mice immunized with OMP of Shigella was determined in relation to Salmonella typhimurium. The doses 1 and 5 micrograms of OMP resulted in slight activation of macrophages which manifested itself by a little increase in their phagocytic and bactericidal ability. When used in the dose 10 micrograms, OMP remained without any effect on the above activity of macrophages. Only the dose 50 micrograms, slightly suppressed their phagocytic properties.     

Two steps in the generation of acquired cellular resistance against Listeria monocytogenes: accumulation and activation of macrophages.

Mice were immunized with 1 X 10(3) viable Listeria monocytogenes, and the mechanism of the acquired resistance against challenge infection with 5 X 10(4) L. monocytogenes was studied by the use of the peritoneal cavity of mice as the site of challenge. An enhanced elimination of bacteria from the peritoneal cavity became detectable on day 5 after immunization, and lasted thereafter. Before day 10 postimmunization, a marked accumulation of macrophages was observed after the challenge but the in vitro listericidal activity of macrophages was not so enhanced. After day 15 postimmunization, peritoneal macrophages did not increase in number after the challenge but the in vitro listericidal activity of macrophages was the stronger. Accumulation of non-activated macrophages seemed to contribute mainly to the expression of acquired resistance against challenge in the early stage of immunization. So-called activated macrophages appeared to be generated only in the later stage of immunization. Thus it was suggested that there may be at least two steps in the expression of acquired listerial resistance.     

The role of serum factors in the suppression of experimental allergic encephalomyelitis: evidence for immunoregulation by antibody to the encephalitogenic peptide.

Lewis rats immunized with myelin basic protein (MBP) in Freund's complete adjuvant (FCA) suffer from a single episode of paralysis from which they recover spontaneously. Subsequent to recovery, further episodes of paralysis cannot normally be induced by reimmunization with MBP in FCA. It is well established that serum, obtained from rats in the refractory state, can suppress the induction of experimental allergic encephalomyelitis (EAE) when given to animals from the time of immunization with MBP in FCA. Here it is shown that treatment with some such sera from Day 7 after immunization also suppressed the disease. However, not all convalescent sera were suppressive, indicating that rats immunized with MBP in FCA could become refractory to EAE without assayable levels of suppressive activity in their sera. In the context of this result it was notable that a correlation was found between the level of antibody specific for the encephalitogenic peptide in sera and the ability to suppress EAE. An inverse relationship was also shown between the amount of anti-encephalitogenic peptide antibody produced after immunization and the severity of EAE induced. Spleen cells from animals treated with Lewis anti-MBP serum after immunization with MBP in FCA could be activated to transfer EAE by in vitro culture with MBP despite the absence of any clinical signs in the donor animals, i.e. the serum inhibited the expansion or differentiation of these cells rather than preventing their priming or bringing about clonal deletion.     

Pulmonary immunity to Pseudomonas aeruginosa in intestinally immunized rats roles of alveolar macrophages, tumor necrosis factor alpha, and interleukin-1 alpha.

The aims of this study were to assess the role played by alveolar macrophages, tumor necrosis factor alpha (TNF-alpha), and interleukin-1 alpha (IL-1 alpha) in pulmonary immunity against Pseudomonas aeruginosa in animals that have been immunized via the gut-associated lymphoid tissue. Following intra-Peyer's patch immunization and subsequent intratracheal challenge with live bacteria, significantly enhanced bacterial clearance from the lungs correlated with an increase in bronchoalveolar neutrophils, increased recruitment and phagocytic activity of alveolar macrophages, and accelerated production of TNF-alpha in the bronchoalveolar space, while levels of IL-1 alpha remained low. Administration of recombinant TNF-alpha in physiological concentrations did not affect the proliferation of P. aeruginosa in vitro, but when given intratracheally to rats at the time of infection, recombinant TNF-alpha significantly increased bacterial clearance from the lungs. In these animals, phagocytic activity of bronchoalveolar neutrophils was enhanced, while the recruitment of alveolar macrophages and neutrophils remained unchanged. In acutely infected nonimmune animals, bronchoalveolar concentrations of soluble IL-1 alpha and TNF-alpha increased until the time of death. Levels of prostaglandin E2 and thromboxane B2 were similar in each experimental group. These results indicate that infection in immune animals enhanced both recruitment and phagocytic activity of alveolar macrophages as well as induced an accelerated production of TNF-alpha. In immune challenged animals, this cytokine enhanced the phagocytic activity of neutrophils and improved bacterial clearance from the lung. Levels of soluble IL-1 alpha and TNF-alpha in nonimmune rats increased consistently following infection until the time of death, thus implicating these cytokines in the pathogenesis of acute P. aeruginosa pneumonia.     

Immunization of BALB/c mice with killed Neospora caninum tachyzoite antigen induces a type 2 immune response and exacerbates encephalitis and neurological disease

BALB/c mice were immunized subcutaneously with soluble Neospora caninum tachyzoite antigen (NSO) entrapped in nonionic surfactant vesicles (NISVs) or administered with Freund's complete adjuvant (FCA). Following virulent parasite challenge, groups of mice immunized with NSO and either NISVs or FCA had clinical neurological disease and increased numbers of brain lesions compared to groups of mice inoculated with FCA, NISVs, or phosphate-buffered saline (PBS) alone. Increased numbers of brain lesions were statistically significant only between mice immunized with NISV-NSO and NISV- or PBS-treated mice. Following parasite challenge, brain inflammatory infiltrates in all experimental and control groups of mice were relatively similar and consisted of compact infiltrates of macrophages admixed with various numbers of lymphoid cells. Increased brain lesions in NSO-immunized mice were associated with increased antigen-specific interleukin 4 (IL-4) secretion and increased IL-4:gamma interferon secretion ratios from splenocytes in vitro and increased antigen-specific immunoglobulin G1 (IgG1):IgG2a ratios in vivo. Thus, immunization with whole killed N. caninum antigen and either liposoidal or Freund's adjuvant induced a type 2 immune response that was associated with worsened disease. The present studies emphasize the need to identify specific N. caninum antigens or other delivery systems that will elicit protective immune responses to neosporosis.     

免疫小鼠及正常小鼠巨噬细胞对利什曼无鞭毛期的吞噬作用

内脏利什曼原虫主要寄生在巨噬细胞系统的单核吞噬细胞内,在一般情况下其无鞭毛期能抵抗巨噬细胞的杀灭作用。 为了观察经杜氏利什曼原虫免疫后的小鼠其巨噬细胞的作用,我们采用了CFW纯系小鼠,经不同免疫方法于免疫后不同时间观察了体外培养中巨噬细胞的吞噬功能。实验采用的巨噬细胞与杜氏利什曼原虫前鞭毛期的比例为1:4。从每24小时吞噬功能的结果表明,经利什曼鞭毛体纯抗原免疫及福氏佐剂加利什曼抗原免疫的两组小鼠,均以免疫后3周的吞噬率最高,分别为72％及96％;两组吞噬指数的均值±SD(4.46±1.72,6.99±4.36)亦较正常组小鼠(1.68±1.25,1.72±1.15)为高,并具有显著差异(P<0.05)。提示了特异性抗原以及与佐剂合并具有对吞噬功能的激活作用。实验并观察了巨噬细胞内利什曼原虫无鞭毛期的活力作用,从吞噬原虫后20小时开始至 144小时,正常小鼠巨噬细胞内的无鞭毛期再经三恩氏培养基培养后均能恢复为前鞭毛期,而经免疫小鼠巨噬细胞内的利什曼原虫无鞭毛期在72小时后即消失活力。 另外,对小鼠腹腔巨噬细胞吞噬利什曼原虫的动态亦作了仔细观察。 实验结果说明了经过免疫的小鼠,由于被淋巴细胞激活后的巨噬细胞能杀死利什曼原虫,巨噬细胞在宿主对感染应答中是一个重要部分,对于探索黑热病的免疫机理具有一     

Immunization of BALB/c Mice with Killed Neospora caninum Tachyzoite Antigen Induces a Type 2 Immune Response and Exacerbates Encephalitis and Neurological Disease

BALB/c mice were immunized subcutaneously with soluble Neospora caninum tachyzoite antigen (NSO) entrapped in nonionic surfactant vesicles (NISVs) or administered with Freund's complete adjuvant (FCA). Following virulent parasite challenge, groups of mice immunized with NSO and either NISVs or FCA had clinical neurological disease and increased numbers of brain lesions compared to groups of mice inoculated with FCA, NISVs, or phosphate-buffered saline (PBS) alone. Increased numbers of brain lesions were statistically significant only between mice immunized with NISV-NSO and NISV- or PBS-treated mice. Following parasite challenge, brain inflammatory infiltrates in all experimental and control groups of mice were relatively similar and consisted of compact infiltrates of macrophages admixed with various numbers of lymphoid cells. Increased brain lesions in NSO-immunized mice were associated with increased antigen-specific interleukin 4 (IL-4) secretion and increased IL-4:gamma interferon secretion ratios from splenocytes in vitro and increased antigen-specific immunoglobulin G1 (IgG1):IgG2a ratios in vivo. Thus, immunization with whole killed N. caninum antigen and either liposoidal or Freund's adjuvant induced a type 2 immune response that was associated with worsened disease. The present studies emphasize the need to identify specific N. caninum antigens or other delivery systems that will elicit protective immune responses to neosporosis.     

Soluble factors in immune sera of mice. I. Specific and non-specific suppressive activity.

Serum collected from mice 7 days following immunization with heterologous erythrocytes (SRBC, HoRBC) contained potent and specific immunosuppressive activity. When the serum was filtered through a Diaflo UM-10 membrane the activity was recovered in the filtrate, indicating that a factor less than 10,000 Daltons is responsible for it. Filtrates obtained from animals immunized with soluble antigens (BSA, POL) in FCA suppressed the 7S response to SRBC but had no effect on the 19S response. This non-specific suppressive effect on the7S response was also shown by filtrates obtained from sera of animals injected with FCA or other adjuvants (LPS, poly A:U). The 19S response to SRBC was either not affectd (LPS, poly A:U) or actually enhanced. (FCA). The SRBC-induced filtrates markedly suppressed the espression of DH to SRBC.     

Protection against influenza A virus infection in mice by oral immunization with a polyvalent bacterial lysate.

A study is presented which investigated whether oral immunization with a polyvalent bacterial lysate (Paspat oral) can sufficiently enhance cell-mediated defense mechanisms to protect mice against influenza A virus infection. It was found that oral immunization reduced mortality due to influenza A infection with 15-70%, depending on the quantity of virus administered and and the moment of infection. Cyclosporin A severely reduced the protective effect of oral immunization, suggesting that a major effect of oral immunization in these studies is T-cell activation. The effect of oral immunization on macrophageal activity was evaluated by measuring cyclic-AMP in alveolar macrophages (AMs) obtained by bronchoalveolar lavage. Before infection, basal activity levels of AMs in immunized mice were significantly lower than in controls. Five days after infection, however, basal activity level of AMs in immunized mice was significantly higher than AM activity in controls. Stimulation of AMs with PGE2 significantly reduced cellular activity in both groups, before and after infection. However, cellular activity of AMs from immunized animals was less reduced than cellular activity of control macrophages. Activity of AMs of immunized animals was significantly more reduced by histamine than activity of control macrophages. It is concluded that oral immunization with Paspat oral stimulates T-cell-dependent immune mechanisms, resulting in protection against influenza A virus infection in mice.     

The induction of lymphocytes with the capacity to render macrophages cytotoxic in an allogeneic murine system.

Sensitized spleen and peripheral lymph node lymphocytes were tested after different types of immunization with allogeneic tumour cells for their capacity to induce macrophage cytotoxicity in vitro. The macrophages were rendered cytotoxic either by direct contact with lymphocytes and tumour cells (activation of macrophages) or by a factor (macrophage arming factor, MAF), released by the sensitized lymphocytes incubated with tumour cells (arming of macrophages). Both types of reactions are T-cell dependent. Macrophage activation is a more sensitive way to detect lymphocytes with the capacity to render macrophages cytotoxic than arming of macrophages. The route of immunization subcutaneously (s.c.) or intraperitoneally (i.p.) with allogeneic cells did not influence the induction of lymphocytes with the capacity to render macrophages cytotoxic. However, the tumour cells had to be intact as disrupted cells (suspended in Freund's complete adjuvant, FCA) did not induce macrophages activating lymphocytes. The adjuvant dimethyl dioctadecyl ammonium bromide (DDA) did not increase the lymphocyte response. Intact allogeneic tumour cells were needed in vitro when used for secondary antigenic stimulation. This secondary stimulation was independent of antigen presentation by macrophages. This suggests that also in vivo the primary response is independent of macrophage antigen presentation. Delayed-type hypersensitivity and antibody responses against the allogeneic tumour cells were comparable after s.c. and i.p. immunization and after immunization with FCA and DDA.     

恶性疟原虫抗原—痘苗病毒重组活疫苗株的实验室评价

以恶性疟原虫保护性抗原复合基因—痘苗病毒重组活疫苗候选株为研究对象 ,探索其免疫血清及IgG的体外抗疟原虫能力、保护性细胞免疫反应及换人血猕猴模型动物抗攻击能力试验。结果表明 ,受检免疫血清及IgG具有一定的体外抑制恶性疟原虫增殖作用。家兔及大白鼠免疫后 4～ 6周血清中可产生明显的IL 2活性 ,免疫后 6周家兔、大白鼠及小白鼠血清IFN的活性水平比免疫前明显升高。免疫后 1个月攻虫 ,免疫猴从第 3天一直到第 12天血检中均未发现疟原虫 ;而非重组痘苗病毒免疫猴第 3天后原虫感染率上升 ,第 6天原虫感染率最高达到 6 0 % ,而后原虫感染率逐渐下降 ,持续 13d ;空白对照猴第 3天后原虫感染率也上升 ,第 8天原虫感染率最高达到 2 5 % ,而后原虫感染率逐渐下降 ,持续 12d。结果初步表明该候选疫苗株具有一定的诱发体液免疫、细胞免疫反应及抗虫体攻击能力 ,值得做进一步的研究。     

Increase of heat-shock protein and induction of gamma/delta T cells in peritoneal exudate of mice after injection of live Fusobacterium nucleatum.

Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans are Gram-negative rod periodontal pathogens. The peritoneal cavity of Institute of Cancer Research (ICR) mice was used as the local infection model. In vivo production of heat-shock proteins (hsp) was studied by injection of 1/10 minimum lethal dose (MLD) of each live bacteria into mice. Heat-shock proteins 70 and 60 were examined in the extract of peritoneal exudate cells (PEC) from mice injected intraperitoneally with either F. nucleatum or A. actinomycetemcomitans by using sodium dodecylsulphate-polyacrylamide gel electrophoresis and immunoblotting analysis. Although hsp are present in PEC without injection of the bacteria, both hsp increased and reached a peak on day 3 after F. nucleatum injection but not after A. actinomycetemcomitans. Kinetic study of gamma/delta cells in PEC after injection of bacteria showed that the increase of gamma/delta T cells was observed only in the PEC from mice injected with F. nucleatum but not A. actinomycetemcomitans. The gamma/delta T cells in PEC were either CD3+ and CD4+ or CD3+ and CD8+. The differential cell count of PEC suggested that gamma/delta T-cell induction is related to the expansion of the macrophage population. The phagocytic and chemiluminescence responses of macrophages against the same bacteria were compared after intensive immunization with live F. nucleatum and A. actinomycetemcomitans. Elevations of chemiluminescence response and phagocytic function by immunization were observed in the macrophages of mice immunized with F. nucleatum. These results suggest the sequential appearance of hsp, gamma/delta T cells and macrophage activation after fusobacterial infection.     

Macrophage Migration as an Index of Immune Status

Peritoneal macrophages from mice and guinea pigs pretreated with Freund's complete adjuvant (FCA) or any other immunostimulant when packed in a glass capillary and placed in a migration chamber migrated to a larger area than macrophages from normal untreated animals. The extent of migration could be correlated with the dose of FCA and the period of treatment. Under optimum conditions the ratio between the areas of migration of macrophages from FCA-treated animals and of macrophages from untreated animals was above 3.0. A close correlation was observed between macrophage migration and delayed type hyper– sensitivity (DTH) response in animals sensitized with ovalbumin or sheep red blood cells. The macrophages of immunostimulant-treated animals had relatively higher phagocytic activity. The macrophage migration index (MMI) appears to be a close correlate of macrophage activation and possibly also of the status of cell mediated immune response.     

Macrophage Migration as an Index of Immune Status

Peritoneal macrophages from mice and guinea pigs pretreated with Freund's complete adjuvant (FCA) or any other immunostimulant when packed in a glass capillary and placed in a migration chamber migrated to a larger area than macrophages from normal untreated animals. The extent of migration could be correlated with the dose of FCA and the period of treatment. Under optimum conditions the ratio between the areas of migration of macrophages from FCA-treated animals and of macrophages from untreated animals was above 3.0. A close correlation was observed between macrophage migration and delayed type hyper- sensitivity (DTH) response in animals sensitized with ovalbumin or sheep red blood cells. The macrophages of immunostimulant-treated animals had relatively higher phagocytic activity. The macrophage migration index (MMI) appears to be a close correlate of macrophage activation and possibly also of the status of cell mediated immune response.     

Macrophage migration as an index of immune status.

Peritoneal macrophages from mice and guinea pigs pretreated with Freund's complete adjuvant (FCA) or any other immunostimulant when packed in a glass capillary and placed in a migration chamber migrated to a larger area than macrophages from normal untreated animals. The extent of migration could be correlated with the dose of FCA and the period of treatment. Under optimum conditions the ratio between the areas of migration of macrophages from FCA-treated animals and of macrophages from untreated animals was above 3.0. A close correlation was observed between macrophage migration and delayed type hypersensitivity (DTH) response in animals sensitized with ovalbumin or sheep red blood cells. The macrophages of immunostimulant-treated animals had relatively higher phagocytic activity. The macrophage migration index (MMI) appears to be a close correlate of macrophage activation and possibly also of the status of cell mediated immune response.     

Relationships among differentiated T-cell subpopulations: II. Cytotoxicity and other functions of T cells specific for nucleated chicken erythrocytes

Relationships among T-cell mediated cytotoxicity, tuberculin type hypersensitivity, Jones-Mote type hypersensitivity and activation of helper T cells were studied in AKR mice by means of target cell destruction (⁵¹Cr-release), footpad reaction, migration inhibition test and antibody production against the trinitrophenyl group. (1) Immunization with chicken red blood cells (CRBC) in saline, Freund's incomplete (FIA) or complete adjuvant (FCA) and fixed-CRBC (FRBC) in FIA or FCA induced delayed hypersensitivity as demonstrated by footpad swelling. (2) Migration inhibition was positive in the group immunized with CRBC in saline or FCA, or FRBC in FCA, but negative in those immunized with CRBC or FRBC in FIA. This may suggest that the former has to be assigned to tuberculin type and the latter to Jones-Mote type. (3) T-cell mediated cytotoxicity by immune spleen cells was detected only in mice immunized with CRBC in saline. (4) Pre-treatment with cyclophosphamide augmented delayed footpad reaction in mice immunized with CRBC in saline, but suppressed cytotoxic activity. (5) FRBC in saline scarcely induced delayed footpad reaction and cytotoxic activity, whereas they activated helper function efficiently. Thus, four types of immunological phenomena, attributable to the functions of T cells, may depend upon distinct subpopulations of differentiated T cells which are raised by different methods of immunization.     

Humoral response in mice immunized with outer membrane proteins of Shigella flexneri

Intraperitoneal immunization of mice with outer membrane proteins (OMP) of Sh. flexneri induced in the animals a synthesis of specific antibodies. Their level determined by ELISA test was found to be relatively low in the sera of animals immunized with a single dose (10 micrograms) of OMP; it was markedly higher in mice immunized with two doses of OMP, and very high after three fold immunization. The specific antibodies maintained in the animals for 8-16 weeks after immunization. Anti-OMP sera given to normal mice by intraperitoneal route protected them not only against challenge with homologous Shigella but also against Proteus and Escherichia.     

旋毛虫Ts87重组蛋白诱发小鼠保护性免疫的研究

为了进一步探讨旋毛虫Ts87基因原核表达重组蛋白的保护性免疫作用 ,本试验用此纯化重组蛋白组分加福氏完全佐剂 (FCA)皮下注射免疫NIH小鼠 3次 ,继以旋毛虫感染性幼虫 2 5 0条攻击 ,攻击后每周取血清测抗体IgG滴度 ,第 35天计数小鼠肌肉幼虫数。结果显示重组蛋白免疫鼠的肌肉幼虫减虫率为4 2 3% ,血清抗Ts87重组蛋白体IgG的几何平均倒数滴度 (GMRT)达到 80 0 0以上 ,均显著高于佐剂组和对照组。Ts87基因表达的重组蛋白可产生明显的保护性免疫作用     

The immunological response of the rat to infection with Taenia taeniaeformis: VII. Immunization by oral and parenteral administration of antigens

Rats immunized with in vitro products and saline-soluble antigens derived from Taenia taeniaeformis were found to be significantly protected against challenge infection. Oral and intraperitoneal administration of antigen solutions alone were effective in stimulating resistance. Adjuvants, however, were required for successful immunization when the antigens were injected intramuscularly. Bordetella pertussis and aluminium hydroxide were able to improve markedly the protective effects of antigens given parenterally by either route, but Freund's complete adjuvant (FCA) was not effective as an adjuvant in this system. Reaginic antibodies to parasite antigens were detected in the sera of rats immunized with parasite antigens and B. pertussis or Al(OH)₃, but none were detected in those given antigens incorporated in FCA. The possible role of reaginic antibodies in immunity to T. taeniaeformis is discussed.

A single dose of antigen given orally produced significant protection. Increasing the number of daily doses of antigen administered orally enhanced the degree of protection to a limited but significant extent. There did not appear, however, to be any advantage to giving large doses (> 1 mg protein) of antigen, or extending the immunizing schedule over several weeks. Reaginic antibodies were not detected in the sera of rats immunized orally, but these animals were resistant to both oral and intravenous challenge infection with parasites. These observations are discussed in relation to the phenomena of immune exclusion of antigen by the gut, and gastrointestinally induced systemic tolerance with respect to IgE production.

Sera from rats immunized by all routes were found to be ineffective in conferring resistance upon recipients when given at the dose of 1 ml/rat. Furthermore, sera from donors vaccinated intramuscularly with saline soluble antigens and B. pertussis increased the susceptibility of recipient rats to infection with T. taeniaeformis. This is in sharp contrast to our previous experience in which we have shown that sera from rats with an active infection are highly effective in passive transfer. Possible reasons for these observations are discussed. The requirements for adequately controlled immunization procedures to assess the contributory effects of adjuvant type and the route of antigen inoculation in immunizing against taeniid infections are emphasized in the discussion.

     

The Efficacy of Posttreatment with Synthetic C-Reactive Protein in Murine Bacterial Peritonitis via Activation of FcγRI-Expressing Kupffer Cells

Pretreatment with synthetic C-reactive protein (CRP), a functional CRP peptide, has the potential to augment macrophage phagocytosis by bacterial challenge. However, the posttreatment is clinically ideal. We investigated the efficacy of posttreatment with synthetic CRP on murine cecal ligation and puncture (CLP), focusing on liver macrophages. Mice received CLP, and 1 h later, synthetic CRP or saline was intraperitoneally administered. Posttreatment with synthetic CRP increased the murine survival after CLP. It reduced viable bacterial counts in the liver 24 h after CLP with an increase in the number of Kupffer cells but not monocyte-derived liver macrophages. Posttreatment with synthetic CRP increased the phagolytic activity of Kupffer cells against Escherichia coli (E. coli) as well as capsulated Klebsiella pneumoniae at 3 h after CLP. Synthetic CRP therapy augmented TNF production by E. coli-phagocytosing Kupffer cells, resulting in an increase in tissue TNF levels in the liver at 24 h. Kupffer cells substantially expressed FcγRI, which is a ligand of CRP, and their FcγRI expression was further increased after CLP. In contrast, synthetic CRP therapy affected neither the phagocytic function of monocyte-derived liver macrophages (showing a weak FcγRI expression) nor their TNF production. Depletion of Kupffer cells in mice inhibited these beneficial effects of synthetic CRP in CLP mice.ConclusionPosttreatment with synthetic CRP effectively improves murine bacterial peritonitis via the activation of phagocytosis of FcγRI-expressing Kupffer cells.