Active migration of polymorphonuclear leukocytes (PMN) through the intestinal crypt epithelium is a hallmark of inflammatory bowel disease and correlates with patient symptoms. Previous in vitro studies have shown that PMN transepithelial migration results in increased epithelial permeability. In this study, we modeled PMN transepithelial migration across T84 monolayers and demonstrated that en...

AIM Individuals with human immunodeficiency virus (HIV) infection were evaluated for evidence of abnormal polymorphonuclear leucocyte (PMN) rigidity, which can alter capillary blood flow. METHODS The transit time of individual PMN through 8 microm pores in a cell transit analyser was used as a measure of cell rigidity. PMN transit time was compared between HIV infected individuals (n=45) with...

OBJECTIVES Steroids, used in preterm premature rupture of membranes (pPROM), to reduce the risk of morbidity and mortality of the preterm neonate, impair the maternal polymorphonuclear leukocyte (PMN)-based immune system. In spite of combination with antibiotics, prenatal and postnatal bacterial infections of mother and child are frequent. This pilot study focuses on the influence of steroids i...

Human polymorphonuclear leukocytes (PMN) activated by fMLP (in the presence of CaCl2, fibrinogen, and cytochalasin B) were able to induce aggregation, cytoplasmic Ca2+ increase, and thromboxane A2 production in coincubated autologousplatelets. Cell-free supernatants prepared from n-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMN were able also to induce platelet activation. Antibodi...

Porphyromonas gingivalis has been implicated as a causative pathogen in periodontitis. Immunotherapeutic approaches have recently been suggested to aid in the clearance of P. gingivalis from disease sites. Because antibody-Fc receptor (FcR) interactions play a role in the effector functions of polymorphonuclear neutrophils (PMN), we evaluated which FcR on PMN from gingival crevicular fluid (GCF...

Severe experimental infections with Cryptosporidium parvum have been reported in immunocompromised animals such as SCID mice (mice without functional T cells and B cells). In a C. parvum infection with 1 x 10(6) oocysts/mouse in SCID beige (SCIDbg) mice (SCID mice lacking functional NK cells), oocyst shedding was first demonstrated 18 days after infection. However, shedding was shown as early a...

Regulated recruitment and clearance of neutrophils (PMN) is the hallmark of competent host defense and resolution of inflammation. We now report that IFN-gamma controls PMN infiltration and modulates IL-6 signaling through its soluble receptor (sIL-6R) to promote their apoptosis and clearance. Induction of peritoneal inflammation in IFN-gamma-deficient (IFN-gamma-/-) mice emphasized that the in...

Polymorphonuclear leukocyte (PMN) migration across the intestinal epithelium closely parallels disease symptoms in patients with inflammatory bowel disease. PMN transepithelial migration (TEM) is a multistep process that terminates with PMN detachment from the apical epithelium into the lumen. Using a unique mAb (GM35), we have previously demonstrated that engagement of the CD44 variant contain...

Macrophages (MF) are the final host cells for multiplication of the intracellular parasite Leishmania major (L. major). However, polymorphonuclear neutrophil granulocytes (PMN), not MF, are the first leukocytes that migrate to the site of infection and encounter the parasites. Our previous studies indicated that PMN phagocytose but do not kill L. major. Upon infection with Leishmania, apoptosis...

During episodes of inflammation, polymorphonuclear leukocyte (PMN) transendothelial migration has the potential to disturb vascular barrier function and give rise to intravascular fluid extravasation and edema. However, little is known regarding innate mechanisms that dampen fluid loss during PMN-endothelial interactions. Using an in vitro endothelial paracellular permeability model, we observe...