Genetic Variability of Antigen B among Echinococcus granulosus Egyptian Isolates

Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively.

Immunopathogenic role of IgG antibody and rantes in house dust mite-induced chronic bronchitis

Based on immunological and clinical examinations, 21 patients were diagnosed as having house dust mite [HDM]-induced chronic bronchitis and classified into three groups according to the clinical presentation of the disease; stable bronchitis, exacerbated bronchitis and asthma on top of bronchitis. Using ELISA, the levels of serum anti-Dermatophagoides farinae and anti-D. pteronyssinus IgG antibodies and plasma RANTES [regulated upon activation, normal T-cell-expressed and secreted; a chemokine with attractive and activator role for eosinophils] were measured in correlation to serum eosinophil cationic protein [ECP, a marker of eosinophil activation and degranulation measured by chemiluminescent immunometric technique]. Using immunoblotting, IgG binding components of D. farinae and D. pteronyssinus were determined providing a clue for diagnosis of HDM-induced chronic bronchitis. Significant higher levels of anti-D. farinae and anti-D. pteronyssinus IgG antibodies and RANTES were found in asthmatic group, followed by exacerbated chronic bronchitis in comparison to stable bronchitis and control groups. ECP level correlated significantly with IgG and RANTES levels in exacerbated bronchitis and asthmatic groups. The results provided evidence that over expression of IgG and RANTES plays a crucial role as mediator in immunopathogenesis of HDM-induced chronic bronchitis and as marker of the immunological changes likely responsible for progression of bronchitis to asthma in HDM-sensitive patients, yet RANTES seemed to be an early indicator. Definition of the immunopathogenic role of IgG and RANTES in HDM-induced bronchitis should enable the manipulation of the critical immune response in the hope of establishing new therapies. D. farinae and D. pteronyssinus antigenic bands at >205 and 205 KDa, respectively, considered together showed 71.4% sensitivity in diagnosis of HDM induced chronic bronchitis and 100% specificity by immunoblotting

Iron -overload regulatory effect on cytokine production by spleen lymphocytes in munine cryptosporidiosis the modulatoncy potential potential of iron chelation therapy on immunity

Iron-overload both aggravates the outcome of infections caused by a variety of microorganisms and exerts subtle effects on immune status by altering the proliferation of T and B cells. The effect of iron-overload on the type of T helper [Th] immunity elicited and the subsequent effect on the susceptibility, course and outcome of Cryptosporidium parvum infection were investigated in the present study. Separate groups of iron-overloaded [40 mg of iron dextran/kg intraperitoneally every other day for 4 weeks before infection] immunocompetent and immunocompromised mice were either infected or infected and received iron chelator [deferoxanime: DFO. 50 mg/kg intraperitoneally every other day from the day of infection]. Spleens were harvested and an enzyme linked immunosorbent assay [ELISA] was performed on spleen culture supernatants for in vitro analysis of interferon-gamma [IFN-gamma] and interleukin [IL]-4. Iron-overload induced a Th2 cytokine response with significantly higher IL-4 and lower IFN-gamma levels compared to infected non- treated control. The infection rate was 100% and the infection was severe and persistent in both immunocompetent and immunocompromised iron-overloaded mice with death of all immunocompromised mice. Iron chelation by DFO enhanced the production of Th1 anticryptosporidial immunity [significantly higher IFN-gamma compared to infected non- treated control] limiting the severity and clearing the infection in iron-overloaded immunocompetent mice [cure rate 100%] and controlling the infection in immunocompromised mice with cure rate 30%, percentage reduction in oocyst shedding 80.8% and mortality rate 10% at the end of the experiment [30 days post infection]. These data indicated that iron-overload negatively affected Th1-mediated immunity in mice with cryptosporidiosis thus altering the susceptibility, course and outcome of infection. Iron-overload represents a risk factor for flaring up of Cryptosporidium parvum infection in absence of any obvious immunosuppressive conditions; hence successful therapy in iron-overloaded hosts depends mainly on iron chelation. The immunomodulatory properties of DFO were elucidated in terms of restoring Th1 immunity in iron-overloaded mice

I mmuno electrotransfer blot analysis of trichinella spiralis excretory secretory adult and muscle larval antigens for serodiagnosis and assessment of cure of experimental trichinosis

The potential use of excretory secretory [ES] T.spiralis muscle larval [ML] and adult antigens in enzyme linked immunoelectrotransfer blot [EITB] assay for reliable early serodiagnosis of experimental trichinosis and for assessment of cure after flubendazole therapy is the aim of the present study. Mice were either experimentally infected with T.spiralis then sacrificed at different time points post-infection [PI]; 7 and14 days PI [early stage of infection] and 21 and 56 days PI [late stages of infection] or infected and treated with flubendazole and sacrificed 21 days PI. Serum samples were collected from infected mice either treated or not as well as from healthy and experimentally infected mice with parasitic infections other than T.spiralis. ES T. spiralis ML and adult antigens were prepared from in vitro cultivated larvae and adults, respectively and used in EITB after separation and characterization using 12% sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing condition. EITB using 55 KDa band of ES T.spiralis ML antigen showed a higher sensitivity [67.5%], specificity [100%] and efficacy [84.7%] in diagnosis of trichinosis compared to other bands of ES ML antigen [P< 0.001]. In addition, it was recognized by sera of infected mice 14 days PI [35% sensitivity at early stage of infection]. Using EITB for diagnosis of trichinosis, bands at 47.5 and 28.3 KDa of ES T.spiralis adult antigen showed sensitivity 32.5 and 30%, respectively, specificity 100% and a higher efficacy [68.23 and 67.05%, respectively] compared to other bands of ES adult antigen [p<0.001]. While EITB using 55KDa band of ES T.spiralis ML antigen is more sensitive for diagnosis of trichinosis compared to 47.5 and 28.3 KDa of ES adult antigens [p< 0.001], the same test using either 47.5 or 28.3 KDa of ES adult antigen is more sensitive [65 and 60%, respectively] for diagnosis of early stage of the disease. Bands at 49, 45 and 36 of ES T.spiralis ML antigen become rapidly negative after cure, hence can be used for assessment of cure

Evaluation of an IgG cystatin capture enzyme-linked immunosorbant assay for the detection of anti-cysteine proteinase antibodies in asymptomatic trichomoniasis patients

All isolates of T. vaginalis release cysteine proteinases proteolytic enzymes that are shed into the vagina or culture medium. Cystatin had been successfully used as a capture agent in ELISA to detect cysteine proteinase antibodies without the need for purified proteinases. ELISA was evaluated in comparison with wet mount microscopy and culture techniques. IgG cystatin capture ELISA proved to be a sensitive and highly specific [100%] assay that could rapidly detect anti-cysteine proteinase antibodies in both vaginal washouts and sera of asymptomatic patients with a sensitivity of 100% and 86.7%, respectively. A defined discrimination between sero-positive and sero-negative individuals was markedly observed for ELISA-vaginal washouts providing a more conclusive diagnosis by this technique

Immunolgical indicators of morbidity in human Schistosoma mansoni: role of vascular endothelial growth factor and anti - soluble egg antigen IgG4 in disease progression

Based on the clinical, parasitologic, sigmoidoscopic and sonographic examinations of 90 Schistosomiasis mansoni patients, they were divided into five groups: Lightly infected, heavily infected, intestinal, early hepatosplenic and periportal fibrosis patients. Using ELISA, the levels of circulating vascular endothelial growth factor [VEGF] and anti-soluble egg antigen [SEA] IgG4 were measured in their sera. Compared with the normal controls, VEGF levels were significantly raised in all schistosomiasis patients groups, except the lightly- infected and intestinal patients as they were insignificantly elevated. The level of VEGF correlated with the disease progression from the lightly-infected to periportal fibrosis patients. It also correlated with the sonographic indicators of portal hypertension, presence of portosystemic collaterals, portal vein dilatation and splenomegaly. Serum IgG4 was significantly raised in only periportal fibrosis and portal hypertension patients

Prophylactic efficacy of recombinant IL-12, clindamycin alone or in combination against experimental reactivated toxoplasmosis

Reactivation of experimental chronic toxoplasmosis was induced by daily IM injection of 0.1 ml hydrocortisone acetate [25 mg/ml] per mouse. Administration of clindamycin [5 mg/kg orally], rIL-12 [0.25 micro g i.p] or combination of both was done once weekly for 3 months course starting 2 days post suppression. The prophylactic effect was assessed by determination of both survival rate and brain cyst counts with histopathological examination of brain sections at different time points post suppression besides the influence of these drug regimens on interferon gamma [IFN-delta] production. All immunocompromised untreated mice exhibited increased brain cyst burdens and reduced IFN-delta production and died due to toxoplasmic encephalitis. Neither clindamycin nor rIL-12 prevented reactivation of chronic infection, however, the slight prolongation of survival was observed. Simultaneous administration of clindamycin and r IL-12 resulted in prevention of reactivation in 73.3% of the mice till the end of the experiment. The combination regimen produced significant higher levels of IFN-delta than either drug alone suggesting that both r IL-12 and clindamycin can act additively or synergistically to prevent reactivation of chronic infection with T. gondii most probably through enhancement of IFN-delta production