bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maturational Changes in Peripheral Lymphocyte Subsets Pertinent to Monitoring Human Immunodeficiency Virus-Infected Chinese Pediatric Patients
Authors: Kam Kai Man , Leung Wai Lin , Wong Ka Hing , Lee Shui Shan , Hung Mi Yim , Kwok Mei Yee 
Published: July 2002

ABSTRACTOn the basis of results of testing of 212 peripheral blood samples from ethnic Chinese individuals in five age groups, ranging from birth to adulthood, by standardized flow cytometry techniques, we studied the maturational processes that are pertinent to monitoring the human immunodeficiency virus (HIV)-infected Chinese pediatric population. While the numbers of peripheral total white cells and percent lymphocytes declined from birth to adulthood, the percent CD3+T lymphocytes was steady among all age groups studied. The numbers of CD3+CD4+(T-helper) cells decreased markedly after the first year of life, followed by a slower decline afterward and then a slight increase before adulthood. The trend for CD3+CD8+(T-suppressor) cells, however, was an increase among individuals of all age ranges. The numbers of CD19+CD3−(B cells) increased only during the first year of life and then declined steadily, while natural killer (NK) cells showed the opposite pattern. Comparison of the results with those of studies done with a Caucasian population showed that both peripheral T-helper and T-suppressor cell numbers were low after the first year of life in the Chinese pediatric population in comparison with those in a Caucasian pediatric population. Lower B-cell counts and higher NK-cell counts were seen after the first year of life in the Chinese population than in the Caucasian population. It is important that for each HIV-infected population normative ranges of the lymphocyte subset be established to monitor HIV-infected pediatric patients.
Highly Active Antiretroviral Therapy in Human Immunodeficiency Virus Type 1-Infected Children: Analysis of Cellular Immune Responses
Authors: Blazevic Vesna , Jankelevich Shirley , Steinberg Seth M. , Jacobsen Freda , Yarchoan Robert , Shearer Gene M. 
Published: July 2002

ABSTRACTThe present study analyzes the effect of highly active antiretroviral therapy (HAART) on restoration of cellular immunity in human immunodeficiency virus (HIV)-infected children over a 24-week period following initiation of HAART with ritonavir, nevirapine, and stavudine. The immunological parameters evaluated at four time points (at enrollment and at 4, 12, and 24 weeks of therapy) included cytokine production by monocytes as well as T-cell proliferation in response to mitogen, alloantigen, and recall antigens including HIV type 1 envelope peptides. Circulating levels of interleukin-16 (IL-16) were measured, in addition to CD4+T-cell counts, plasma HIV RNA levels, and the delayed-type hypersensitivity (DTH) response. At enrollment the children exhibited defects in several immune parameters measured. Therapy increased CD4+T-cell counts and decreased viral loads significantly. By contrast, the only immunological parameter that was significantly increased was IL-12 p70 production by monocytes; the DTH response toCandida albicansalso showed a strong increase in patients becoming positive. In conclusion, these results demonstrate that HAART in HIV-infected children affects the dynamics of HIV replication and the CD4+T-cell count over 24 weeks, similar to the pattern seen in HIV-infected adults. Furthermore, these data indicate improvement in antigen-presenting cell immunological function in HIV-infected children induced by HAART.
Monoclonal Antibodies to Immunodominant Epitope ofTropheryma whipplei
Authors: Liang Zhongxing , La Scola Bernard , Raoult Didier 
Published: July 2002

ABSTRACTRecent isolation ofTropheryma whipplei(formerlyTrophyrema whippelii), the agent of Whipple’s disease, from the cardiac valve of a patient with Whipple’s disease endocarditis now allows the detection of reactive epitopes that could be used in a serological assay. In order to propose an enzyme-linked immunosorbent assay (ELISA) that uses recombinantT. whippleiantigen, we first determined by Western blotting of human, mouse, and rabbit antisera that the common immunodominant epitope is an 84-kDa protein. We then produced 13 monoclonal antibodies (MAbs) againstT. whipplei, 12 of which recognize this immunodominant epitope. These MAbs did not react with phylogenetically closely related bacteria or bacteria previously shown to be cross-reactive withT. whipplei, but they did react with two other strains ofT. whippleiisolated, one from an ocular sample and the other from a duodenal biopsy specimen. By confocal microscopy, the MAbs allowed detection ofT. whippleiwithin infected fibroblasts. The identification of the 84-kDa antigen with our MAbs will make it possible to develop a diagnostic antigen for use in a diagnostic ELISA for Whipple’s disease.
Development and Evaluation of an In-House Enzyme-Linked Immunosorbent Assay for Early Diagnosis and Monitoring of Human Pythiosis
Authors: Krajaejun Theerapong , Kunakorn Mongkol , Niemhom Sopaporn , Chongtrakool Piriyaporn , Pracharktam Roongnapa 
Published: July 2002

ABSTRACT

Human pythiosis is an emerging, fatal, infectious disease caused by
Pythium insidiosum
and occurs in both tropical and subtropical countries. Thalassemic patients, farmers, and aquatic-habitat residents are predisposed to this disease. Delayed treatment due to the long time required for isolation and identification of the causative organism, as well as the difficulty in obtaining internal organ specimens, results in high morbidity and mortality. To facilitate rapid diagnosis, an in-house enzyme-linked immunosorbent assay (ELISA) for the detection of immunoglobulin G antibodies against
P. insidiosum
was developed and evaluated for the diagnosis and monitoring of human pythiosis. Sixteen sera were collected from seven culture-proven human pythiosis cases. A total of 142 sera from thalassemic patients, from patients with other infectious diseases, and from healthy blood donors served as controls. All sera were tested in duplicate. By choosing a suitable cutoff point to maximize sensitivity and specificity, sera from pythiosis cases were all determined to be positive, whereas sera from control groups were all determined to be negative. ELISA signals from serial samples of sera taken from treated patients showed gradually declining levels of antibodies to
P. insidiosum
. The ELISA test was highly sensitive (100%) and specific (100%) and was useful for early diagnosis and for monitoring the treatment for pythiosis.
Newly Characterized Species-Specific ImmunogenicChlamydophila pneumoniaePeptide Reactive with Murine Monoclonal and Human Serum Antibodies
Authors: Marston Eric L. , James Andrea V. , Parker J. Todd , Hart John C. , Brown Teresa M. , Messmer Trudy O. , Jue Danny L. , Black Carolyn M. , Carlone George M. , Ades Edwin W. , Sampson Jacquelyn 
Published: July 2002

ABSTRACTA monoclonal antibody (MAb) directed against an unknownChlamydophila pneumoniaeepitope has been characterized, and the respective peptide mimotope has been identified. A murine MAb specific forC.pneumoniaewas used to select peptides from phage display libraries. The peptides identified from the phage display library clones reacted specifically with the respective target murine MAb and with human sera previously identified as having antibody titers toC. pneumoniae. The selected peptide mimotope sequences tended to be composed of charged residues surrounding a core of hydrophobic residues. The peptide with the best binding could inhibit >95% of binding to the MAb, suggesting that the selected peptide binds the paratope of the respective MAb. The peptide reacted with human sera previously determined by microimmunofluorescence to have anti-C. pneumoniaeantibodies. The peptide was competitively competed with the MAb against Renografin-purified, sonicatedC. pneumoniaein an enzyme-linked immunosorbent assay and with whole-cellC. pneumoniaein an indirect fluorescence assay format, demonstrating its potential utility in the development of diagnostics. The use of this novel peptide may allow investigators to establish standardized assays free from cross-reactiveChlamydia trachomatisandChlamydophila psittaciepitopes and immunoreactivity.
Expression of Mucosal Homing Receptor α4β7 Is Associated with Enhanced Migration to theChlamydia-Infected Murine Genital Mucosa In Vivo
Authors: Hawkins Raymond A. , Rank Roger G. , Kelly Kathleen A. 
Published: July 2002

ABSTRACTThe CD4 T helper cell type 1 (Th1) response is essential for the resolution of chlamydial genital infection in mice. However, not all Th1 clones are equally protective in eradicating the infection. Since oral immunization regimens produce protective immunity, we evaluated the role of the mucosa-associated homing receptor, α4β7, in trafficking to the genital mucosa. Using a panel of CD4, Th1 cell lines and clones, we compared the lymphocyte homing patterns of aChlamydia-specific, protective clone (P-MoPn), a nonprotective clone (N-MoPn), and a keyhole limpet hemocyanin (KLH)-specific cell line (KLH-1). T cells were labeled with the fluorescent dye PKH-26, adoptively transferred intoChlamydia-infected mice, and monitored at different time points throughout the course of a genital infection. We found that clones P-MoPn and N-MoPn migrated to similar extents to the genital tract and in significantly greater numbers than the KLH-specific T-cell line. Both clones and the KLH-1 line expressed similar levels of the adhesion molecules α4, β1, CD44, and CD11a. However, clones P-MoPn and N-MoPn expressed higher levels of the mucosal homing receptor, α4β7. Also, clones P-MoPn and N-MoPn but not the KLH-1 line migrated to the mesenteric lymph node, suggesting a mucosal recirculation pattern. Moreover, blocking α4β7 adhesion interaction in vivo significantly reduced the recruitment of P-MoPn but not KLH-1 to the genital tract. These findings show that the mucosal homing receptor α4β7 is utilized by a subset of CD4 cells during migration to theChlamydia-infected genital tract.
Infection of Human Endothelial Cells withBartonella bacilliformisIs Dependent on Rho and Results in Activation of Rho
Authors: Verma Anita , Davis George E. , Ihler Garret M. 
Published: July 2002

ABSTRACTBartonella bacilliformiswas continuously internalized into human endothelial cells beginning shortly after addition of the bacteria and continuing for at least 24 h after infection in vitro, with a major increase in uptake occurring between 16 and 24 h. Preincubation of endothelial cells with C3 exoenzyme, which inactivated intracellular Rho-GTPase, blocked internalization of the bacteria. Addition of C3 exoenzyme at any time after addition of the bacteria blocked further internalization of bacteria, including the major uptake of bacteria internalized at 16 to 24 h. Rho, a key signaling protein in pathways involving actin organization, was directly shown to be activated in endothelial cells undergoing infection withB. bacilliformis, with maximal activation and translocation to the plasma membrane at 12 to 16 h. At late times of infection, most of the bacteria were found in a perinuclear location. Staining of the Golgi complex with specific markers, anti-human Golgin-97, anti-KDEL receptor, and BODIPY-TR ceramide, showed colocalization of bacteria in the Golgi complex region. Disruption of the Golgi complex with brefeldin A scattered the bacteria from this perinuclear location and resulted in inhibition of internalization of the bacteria in endothelial cells.
Pseudomonas aeruginosa
ExoT Is a Rho GTPase-Activating Protein
Authors: Krall Rebecca , Schmidt Gudula , Aktories Klaus , Barbieri Joseph T. 
Published: July 2002

ABSTRACT
Transient intracellular expression of ExoT in CHO cells stimulated cell rounding and actin reorganization. Biochemical studies showed that ExoT was a GTPase-activating protein for RhoA, Rac1, and Cdc42. Together, these data show that ExoT interferes with Rho signal transduction pathways, which regulate actin organization, exocytosis, cell cycle progression, and phagocytosis.
Multiple Roles forBordetellaLipopolysaccharide Molecules during Respiratory Tract Infection
Authors: Harvill Eric T. , Preston Andrew , Cotter Peggy A. , Allen Andrew G. , Maskell Duncan J. , Miller Jeff F. 
Published: July 2002

ABSTRACTBordetella pertussis,Bordetella parapertussis, andBordetella bronchisepticaare closely related subspecies that cause respiratory tract infections in humans and other mammals and express many similar virulence factors. Their lipopolysaccharide (LPS) molecules differ, containing either a complex trisaccharide (B. pertussis), a trisaccharide plus an O-antigen-like repeat (B. bronchiseptica), or an altered trisaccharide plus an O-antigen-like repeat (B. parapertussis). Deletion of thewlblocus results in the loss of membrane-distal polysaccharide domains in the three subspecies of bordetellae, leaving LPS molecules consisting of lipid A and core oligosaccharide. We have usedwlbdeletion (Δwlb) mutants to investigate the roles of distal LPS structures in respiratory tract infection by bordetellae. Each mutant was defective compared to its parent strain in colonization of the respiratory tracts of BALB/c mice, but the location in the respiratory tract and the time point at which defects were observed differed significantly. Although the Δwlbmutants were much more sensitive to complement-mediated killing in vitro, they displayed similar defects in respiratory tract colonization in C5−/−mice compared with wild-type (wt) mice, indicating that increased sensitivity to complement-mediated lysis is not sufficient to explain the in vivo defects.B. pertussisandB. parapertussis Δwlbmutants were also defective compared to wt strains in colonization of SCID-beige mice, indicating that the defects were not limited to interactions with adaptive immunity. Interestingly, theB. bronchiseptica Δwlbstrain was defective, compared to the wt strain, in colonization of the respiratory tracts of BALB/c mice beginning 1 week postinoculation but did not differ from the wt strain in its ability to colonize the respiratory tracts of B-cell- and T-cell-deficient mice, suggesting thatwlb-dependent LPS modifications inB. bronchisepticamodulate interactions with adaptive immunity. These data show that biosynthesis of a full-length LPS molecule by these three bordetellae is essential for the expression of full virulence for mice. In addition, the data indicate that the different distal structures modifying the LPS molecules on these three closely related subspecies serve different purposes in respiratory tract infection, highlighting the diversity of functions attributable to LPS of gram-negative bacteria.
Involvement of CD14 and β2-Integrins in Activating Cells with Soluble and Particulate Lipopolysaccharides and Mannuronic Acid Polymers
Authors: Flo Trude H. , Ryan Liv , Kilaas Lars , Skjåk-Bræk Gudmund , Ingalls Robin R. , Sundan Anders , Golenbock Douglas T. , Espevik Terje 
Published: July 2002

ABSTRACTLipopolysaccharide (LPS) and related bacterial products can be recognized by host inflammatory cells in a particulate, bacterium-bound form, as well as in various soluble, released forms. In the present study we have compared the mechanisms used by LPS, detoxified LPS (DLPS), and mannuronic acid polymers (M-polymers), in solution or covalently linked to particles, in stimulating monocytes to tumor necrosis factor (TNF) production. The addition of recombinant LPS binding protein (LBP) and/or soluble CD14 (sCD14) enhanced the production of TNF from monocytes stimulated with soluble LPS, DLPS, or M-polymer, but did not affect the response to M-polymer or DLPS attached to particles. Treatment of monocytes with antibody to CD14, CD18, or CD11b showed that CD14, but not CR3 (CD11b/CD18), mediated monocyte TNF production in response to the soluble antigens. In contrast, anti-CD14, anti-CD11b and anti-CD18 monoclonal antibodies all inhibited the response to the particulate stimuli. On the other hand, B975, a synthetic analog ofRhodobacter capsulatuslipid A, completely abrogated the monocyte TNF response induced by LPS but did not affect the TNF induction by DLPS or M-polymer, either in soluble or particulate forms. These data demonstrate that the engagement of immune receptors by bacterial products such as LPS, DLPS, and M-polymer is dependent upon the presentation form of their constituent carbohydrates, and that factors such as aggregation state, acylation, carbohydrate chain length, and solid versus liquid phase of bacterial ligands influence the mechanisms used by cells in mediating proinflammatory responses.
Impaired Bone Resorption by Lipopolysaccharide In Vivo in Mice Deficient in the Prostaglandin E Receptor EP4 Subtype
Authors: Sakuma Yoko , Tanaka Kiyoshi , Suda Michio , Komatsu Yasato , Yasoda Akihiro , Miura Masako , Ozasa Ami , Narumiya Shuh , Sugimoto Yukihiko , Ichikawa Atsushi , Ushikubi Fumitaka , Nakao Kazuwa 
Published: July 2002

ABSTRACT
In a previous study we showed that the involvement of EP4 subtype of the prostaglandin E (PGE) receptor is crucial for lipopolysaccharide (LPS)-induced osteoclast formation in vitro. The present study was undertaken to test whether EP4 is actually associated with LPS-induced bone resorption in vivo. In wild-type (WT) mice, osteoclast formation in vertebrae and tibiae increased 5 days after systemic LPS injection, and urinary excretion of deoxypyridinoline, a sensitive marker for bone resorption, statistically increased 10 days after injection. In EP4 knockout (KO) mice, however, LPS injection caused no significant changes in these parameters throughout the experiment. LPS exposure for 4 h strongly induced osteoclast differentiation factor (ODF) mRNA expression in primary osteoblastic cells (POB) both from WT and EP4 KO mice, and this expression was not inhibited by indomethacin, suggesting prostaglandin (PG) independence. LPS exposure for 24 h further induced ODF expression in WT POB, but not in EP4 KO POB. Indomethacin partially inhibited ODF expression in WT POB, but not in EP4 KO POB. These data suggest that ODF is induced both PG dependently and PG independently. LPS exposure for 24 h induced slightly greater osteoclastgenesis inhibitory factor (OCIF) mRNA expression in EP4 KO than in WT POB. These findings suggest that the reduced ODF expression and apparently increased OCIF expression also are responsible for the markedly reduced LPS-induced osteoclast formation in EP4 KO mice. Our results show that the EP4 subtype of the PGE receptor is involved in LPS-induced bone resorption in vivo also. Since LPS is considered to be largely involved in bacterially induced bone loss, such as in periodontitis and osteomyelitis, our study is expected to help broaden our understanding of the pathophysiology of these conditions.
mig-14Is a Horizontally Acquired, Host-Induced Gene Required forSalmonella entericaLethal Infection in the Murine Model of Typhoid Fever
Authors: Valdivia Raphael H. , Cirillo Daniela M. , Lee Anthea K. , Bouley Donna M. , Falkow Stanley 
Published: July 2002

ABSTRACTWe have characterized a host-induced virulence gene,mig-14, that is required for fatal infection in the mouse model of enteric fever.mig-14is present in allSalmonella entericasubspecies I serovars and maps to a region of the chromosome that appears to have been acquired by horizontal transmission. Amig-14mutant replicated in host tissues early after infection but was later cleared from the spleens and livers of infected animals. Bacterial clearance by the host occurred concomitantly with an increase in gamma interferon levels and recruitment of macrophages, but few neutrophils, to the infection foci. We hypothesize that themig-14gene product may repress immune system functions by interfering with normal cytokine expression in response to bacterial infections.
Secreted Enzymatic Activities of Wild-Type and
pilD
-Deficient
Legionella pneumophila
Authors: Aragon Virginia , Kurtz Sherry , Flieger Antje , Neumeister Birgid , Cianciotto Nicholas P. 
Published: July 2002

ABSTRACT

Legionella pneumophila
, the agent of Legionnaires' disease, is an intracellular pathogen of protozoa and macrophages. Previously, we had determined that the
Legionella pilD
gene is involved in type IV pilus biogenesis, type II protein secretion, intracellular infection, and virulence. Since the loss of pili and a protease do not account for the infection defect exhibited by a
pilD
-deficient strain, we sought to define other secreted proteins absent in the mutant. Based upon the release of
p
-nitrophenol (pNP) from
p
-nitrophenyl phosphate, acid phosphatase activity was detected in wild-type but not in
pilD
mutant supernatants. Mutant supernatants also did not release either pNP from
p
-nitrophenyl caprylate and palmitate or free fatty acid from 1-monopalmitoylglycerol, suggesting that they lack a lipase-like activity. However, since wild-type samples failed to release free fatty acids from 1,2-dipalmitoylglycerol or to cleave a triglyceride derivative, this secreted activity should be viewed as an esterase-monoacylglycerol lipase. The mutant supernatants were defective for both release of free fatty acids from phosphatidylcholine and degradation of RNA, indicating that PilD-negative bacteria lack a secreted phospholipase A (PLA) and nuclease. Finally, wild-type but not mutant supernatants liberated pNP from
p
-nitrophenylphosphorylcholine (pNPPC). Characterization of a new set of mutants defective for pNPPC-hydrolysis indicated that this wild-type activity is due to a novel enzyme, as opposed to a PLC or another known enzyme. Some, but not all, of these mutants were greatly impaired for intracellular infection, suggesting that a second regulator or processor of the pNPPC hydrolase is critical for
L. pneumophila
virulence.
Group B Streptococci and Other Gram-Positive Cocci Bind to Cytokeratin 8
Authors: Tamura Glen S. , Nittayajarn Aphakorn 
Published: July 2002

ABSTRACT

Group B streptococci (GBS) adhere to surface receptors present on epithelial cells; these receptors include fibronectin and laminin. To identify other possible receptors, plasma membranes from A549 cells, a respiratory tract epithelial cell line, were prepared. These plasma membranes were tested in a protein blot analysis using radiolabeled GBS as a probe. GBS adhered to two species, with molecular masses of 50 kDa (p50) and 57 kDa (p57). We concluded that p50 and p57 correspond to two forms of cytokeratin 8 (CK8) on the basis of the following results: (i) protein blot results demonstrated that p50 and p57 exactly comigrated with two forms of CK8 after separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (PAGE); (ii) p50 and p57 exactly comigrated with CK8 after separation by two-dimensional PAGE; (iii) CK8 in solution bound to GBS, as demonstrated by immunoblot analysis of proteins from A549 lysates that bound to GBS in a liquid-phase assay; and (iv) radiolabeled GBS bound to A549 lysate-derived CK8 that had been captured in anti-CK8-coated microtiter wells. CK8 bound to COH1-13, an acapsular mutant of COH1, demonstrating that adherence is not mediated by capsular polysaccharide. Trypsin-treated GBS did not bind to CK8, indicating that adherence is mediated via a protein on the surface of GBS. Soluble CK8 bound to six of six GBS strains tested. Soluble CK8 also bound to
Staphylococcus aureus
,
Lactococcus lactis
,
Enterococcus faecalis
, and
Streptococcus pyogenes
. We hypothesize that adherence of GBS to cytokeratin may be important for maintenance of colonization at sites of keratinized epithelium, such as the vagina, or for adherence of these bacteria to damaged epithelial cells at other sites.