Abstract:
:Protective immunity to Plasmodium falciparum malaria acquired after natural exposure is largely antibody mediated. IgG-specific P. falciparum EMP1 (PfEMP1) proteins on the infected erythrocyte surface are particularly important. The transient antibody responses and the slowly acquired protective immunity probably reflect the clonal antigenic variation and allelic polymorphism of PfEMP1. However, it is likely that other immune-evasive mechanisms are also involved, such as interference with formation and maintenance of immunological memory. We measured PfEMP1-specific antibody levels by enzyme-linked immunosorbent assay (ELISA) and memory B-cell frequencies by enzyme-linked immunosorbent spot (ELISPOT) assay in a cohort of P. falciparum-exposed nonpregnant Ghanaian women. The antigens used were a VAR2CSA-type PfEMP1 (IT4VAR04) with expression restricted to parasites infecting the placenta, as well as two commonly recognized PfEMP1 proteins (HB3VAR06 and IT4VAR60) implicated in rosetting and not pregnancy restricted. This enabled, for the first time, a direct comparison in the same individuals of immune responses specific for a clinically important parasite antigen expressed only during well-defined periods (pregnancy) to responses specific for comparable antigens expressed independent of pregnancy. Our data indicate that PfEMP1-specific B-cell memory is adequately acquired even when antigen exposure is infrequent (e.g., VAR2CSA-type PfEMP1). Furthermore, immunological memory specific for VAR2CSA-type PfEMP1 can be maintained for many years without antigen reexposure and after circulating antigen-specific IgG has disappeared. The study provides evidence that natural exposure to P. falciparum leads to formation of durable B-cell immunity to clinically important PfEMP1 antigens. This has encouraging implications for current efforts to develop PfEMP1-based vaccines.
journal_name
Infect Immunjournal_title
Infection and immunityauthors
Ampomah P,Stevenson L,Ofori MF,Barfod L,Hviid Ldoi
10.1128/IAI.01514-13subject
Has Abstractpub_date
2014-05-01 00:00:00pages
1860-71issue
5eissn
0019-9567issn
1098-5522pii
IAI.01514-13journal_volume
82pub_type
杂志文章abstract::Growing Streptococcus gordonii Spp+ phase variants, which have normal levels of glucosyltransferase (GTF) activity, use sucrose to promote their accumulation on surfaces by forming a cohesive bacterium-insoluble glucan polymer mass (BPM). Spp- phase variants, which have lower levels of GTF activity, do not form BPMs a...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.60.10.4301-4308.1992
更新日期:1992-10-01 00:00:00
abstract::Seven cathepsin B-like cysteine proteases (CBLs) were identified from the immunoprotective excretory-secretory products of Haemonchus contortus. Two-dimensional (2-D) zymography and biotinylated inhibitors were employed to localize active CBLs in 2-D protein gels. Mass spectrometry provided the identification of AC-4,...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.74.3.1989-1993.2006
更新日期:2006-03-01 00:00:00
abstract::We studied apoptosis in a human ileocecal adenocarcinoma tumor cell line (HCT-8) infected with Cryptosporidium parvum, from 2 to 72 h postinfection (h.p.i.). At 2 h.p.i., the percentage of annexin V-positive cells in the cell culture had increased to 10% compared to 2.5% in noninfected control culture; sorted infected...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.10.6061-6067.2004
更新日期:2004-10-01 00:00:00
abstract::Phase 1 and 2 clinical trials of group B streptococcal (GBS) capsular polysaccharide (CPS)-protein conjugate vaccines in healthy adults have demonstrated their safety and improved immunogenicity compared with uncoupled CPSs. Two recent trials sought to determine (i) whether adsorption of conjugate vaccine to aluminum ...
journal_title:Infection and immunity
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1128/IAI.69.11.6696-6701.2001
更新日期:2001-11-01 00:00:00
abstract::Lipopolysaccharide (LPS) has recently been shown to facilitate macrophage foam cell formation and has been suggested to be a proatherogenic factor. The mechanism of LPS induced cholesterol accumulation, however, is unclear. In this report, using the macrophage-like RAW 264.7 cell line, we provide experimental evidence...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.6.2995-3003.2002
更新日期:2002-06-01 00:00:00
abstract::The serum antibody response to proteins encoded by the virulence-associated plasmid of Shigella flexneri was determined in monkeys challenged with virulent S. flexneri serotype 2a. With water-extractable antigen in an enzyme-linked immunosorbent assay, a significant increase in antibody titer against proteins from a p...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.53.1.57-63.1986
更新日期:1986-07-01 00:00:00
abstract::Guinea pigs were treated with anti-CD18 antibody (M8), and subsequently middle ears (ME) were infected with nontypeable Haemophilus influenzae. Forty-eight hours after infection, the ME washes of these animals had significantly lower polymorphonuclear leukocyte numbers but higher bacterial counts compared with washes ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.3.1132-1135.1993
更新日期:1993-03-01 00:00:00
abstract::Livers of normal mice trapped over 80% of intravenously injected 51Cr-labeled lipopolysaccharide after 1 h. Liver fractionation studies showed that nearly 45% of the labeled endotoxin was associated with cell nuclei, 20% with the mitochondrial-lysosomal fraction, and approximately 30% with the cell sap. Analysis of th...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.14.1.100-105.1976
更新日期:1976-07-01 00:00:00
abstract::Bovine tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) cDNAs were generated by reverse transcription and then by PCR amplification from lipopolysaccharide (LPS)-stimulated alveolar macrophage RNA. The amplified cDNAs were cloned into pPow and expressed in Escherichia coli DH5 alpha. The expr...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.2.381-388.1995
更新日期:1995-02-01 00:00:00
abstract::Sensitized mouse spleen cells decrease the spread of herpes simplex virus infection in cell culture lines derived from human and murine tissues. These washed, sensitized cells act alone and additively in combination with antibody to diminish the ability of single virus-infected cells to spread infection to contiguous ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.7.6.898-904.1973
更新日期:1973-06-01 00:00:00
abstract::The interaction between human neutrophils and wild-type Bordetella pertussis or mutants expressing altered lipopolysaccharide or lacking virulence factors-pertussis toxin, adenylate cyclase toxin, dermonecrotic toxin, filamentous hemagglutinin (FHA), pertactin, or BrkA-was examined. In the absence of antibodies, the w...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.3.1735-1739.2000
更新日期:2000-03-01 00:00:00
abstract::Erythrocytic malaria parasites degrade hemoglobin as a principal source of amino acids for parasite protein synthesis. We have previously shown that a Plasmodium falciparum trophozoite cysteine proteinase, now termed falcipain, is required for hemoglobin degradation, and we have hypothesized that this proteinase is re...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.63.6.2120-2125.1995
更新日期:1995-06-01 00:00:00
abstract::The derivative toxins purified from cultures of proteolytic strains of Clostridium botulinum types A and F were found to have been only partially nicked but were fully activated. Trypsinization of C. botulinum type B derivative toxin at pH 6.0 resulted in simultaneous activation and nicking, whereas at pH 4.5, activat...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.17.2.402-407.1977
更新日期:1977-08-01 00:00:00
abstract::Mycoplasma hyorhinis organisms were fractionated into lipid, carbohydrate, and protein fractions by chemical and physiochemical procedures. When all fractions were tested for complement fixation and inhibition of growth inhibition activity, only the protein fractions possessed activity. Thus, it appears that the major...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.7.6.937-940.1973
更新日期:1973-06-01 00:00:00
abstract::The ability of intracellular pathogens to sense and adapt to the hostile environment of the host is an important factor governing virulence. We have sequenced the operon encoding the major heat shock proteins GroES and GroEL in the gram-positive food-borne pathogen Listeria monocytogenes. The operon has a conserved or...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.6.3924-3932.2001
更新日期:2001-06-01 00:00:00
abstract::Human granulocytic ehrlichiosis (HGE) is an emerging febrile systemic disease caused by the HGE agent, an obligatory intracellular bacterium of granulocytes. The pathogenicity- and immunity-related mechanisms of HGE are unknown. In this study, several cytokines generated in human peripheral blood leukocytes (PBLs) inc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.6.3394-3402.2000
更新日期:2000-06-01 00:00:00
abstract::C4BP (C4b-binding protein) is a high-molecular-weight plasma protein that inhibits the classical pathway of complement activation. Recent experiments have demonstrated that C4BP binds to many strains of the gram-positive bacterium Streptococcus pyogenes, a major respiratory tract pathogen. Binding to S. pyogenes was s...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.65.9.3638-3643.1997
更新日期:1997-09-01 00:00:00
abstract::Culture filtrate proteins from Mycobacterium tuberculosis induce protective immunity in various animal models of tuberculosis. Two molecular mass regions (6 to 10 kDa and 24 to 36 kDa) of short-term culture filtrate are preferentially recognized by Th1 cells in animal models as well as by patients with minimal disease...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.66.6.2728-2735.1998
更新日期:1998-06-01 00:00:00
abstract::Bovine septicemic Escherichia coli 31A agglutinates bovine, rabbit, and human erythrocytes and adheres in vitro to the brush border of bovine or ovine intestinal epithelial cells and to the human colon carcinoma Caco-2 cell line. The adhesion and hemagglutination of E. coli 31A are mediated by a chromosome-encoded fim...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.64.1.332-342.1996
更新日期:1996-01-01 00:00:00
abstract::Adoptive immunity is poorly expressed in normal syngeneic mice. This phenomenon was studied by using experimental antituberculosis immunity as a model system representing pure cell-mediated immunity. Expression of adoptive immunity was facilitated by pretreating recipients with sublethal ionizing radiation (500 rads) ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.41.1.257-263.1983
更新日期:1983-07-01 00:00:00
abstract::Many pathogenic Escherichia coli produce the toxin alpha-hemolysin (Hly), and lipopolysaccharide (LPS), interleukin-1 (IL-1), and tumor necrosis factor (TNF) have all been recognized as important effector molecules during infections by gram-negative organisms. Despite the characterization of many in vitro effects of h...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:
更新日期:1998-09-01 00:00:00
abstract::Development of an effective vaccine against Leishmania infection is a priority of tropical disease research. We have recently demonstrated protection against Leishmania major in the murine and nonhuman primate models with individual or combinations of purified leishmanial recombinant antigens delivered as plasmid DNA ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.70.8.4215-4225.2002
更新日期:2002-08-01 00:00:00
abstract::Establishment and maintenance of chronic lung infections with mucoid Pseudomonas aeruginosa in patients with cystic fibrosis (CF) require that the bacteria avoid host defenses. Elaboration of the extracellular, O-acetylated mucoid exopolysaccharide, or alginate, is a major microbial factor in resistance to immune effe...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.69.3.1895-1901.2001
更新日期:2001-03-01 00:00:00
abstract::A purified A-antigen preparation of Blastomyces dermatitidis was determined to be composed of five major glycoprotein bands, visible with Coomassie blue and periodic acid-Schiff staining of polyacrylamide gels. At least 20 additional protein bands were detected by using a silver stain, which was 100 times more sensiti...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.33.1.171-177.1981
更新日期:1981-07-01 00:00:00
abstract::Two inbred mouse strains, derived from feral founders, are susceptible to experimental leishmaniasis due to Leishmania major and support a disease of a severity intermediate between those observed in strains C57BL/6 and BALB/c. Mice of the MAI strain develop a severe, nonhealing, but nonfatal disease with no resistanc...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.72.8.4603-4611.2004
更新日期:2004-08-01 00:00:00
abstract::In vitro studies have shown that enterotoxigenic Escherichia coli (ETEC) strains are capable of invading cultured epithelial cells derived from the human ileum and colon. Two separate invasion loci (tia and tib) have previously been isolated from the classical ETEC strain H10407. The tia locus has been shown to direct...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/iai.68.12.6595-6601.2000
更新日期:2000-12-01 00:00:00
abstract::The yield of infectious Chlamydia trachomatis was analyzed in human (HeLa) and mouse (McCoy) cell lines treated with the human interferon (IFN) subtypes IFN-alpha A and IFN-alpha D, with their hybrids [IFN-alpha AD (BglII), IFN-alpha AD (PvuII), and IFN-alpha DA (BglII)] constructed in vitro from their expression plas...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.47.3.719-722.1985
更新日期:1985-03-01 00:00:00
abstract::Isolates of Thermoplasma acidophilum were divided into serological groups based on immunodiffusion studies of solubilized-membrane preparations. ...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.10.1.280-281.1974
更新日期:1974-07-01 00:00:00
abstract::Vibrio parahaemolyticus is a gram-negative marine bacterium. A limited population of the organisms causes acute gastroenteritis in humans. Almost all of the clinical V. parahaemolyticus isolates exhibit beta-type hemolysis on Wagatsuma agar, known as the Kanagawa phenomenon (KP). KP is induced by the thermostable dire...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.01535-07
更新日期:2008-03-01 00:00:00
abstract::To study responses to Mycobacterium leprae antigens, we developed an in vitro model system in which latex particles coated with M. leprae sonic extract (MLSON) antigen were presented to monocytes. Uptake and oxidative response as measured by superoxide production to these antigens were investigated. Phagocytosis of ML...
journal_title:Infection and immunity
pub_type: 杂志文章
doi:10.1128/IAI.61.9.3724-3729.1993
更新日期:1993-09-01 00:00:00