B7-2 requirement for helminth-induced granuloma formation and CD4 type 2 T helper cell cytokine expression

B7 ligands on APCs engage CD28/CTLA4 counter-receptors on T cells critical for T lymphocyte activation and functional differentiation of T helper subsets. To examine whether the ligands B7-1 (CD80) and B7-2 (CD86) affect gene expression of Th2 cytokines and development of Th2-mediated pathologic tissue reactions, mice were treated with anti-B7-1 or anti-B7-2 at the time of sensitization to footpad inoculation of Schistosoma mansoni eggs or induction of pulmonary granuloma by i.v. injected eggs. Anti-B7-2 treatment inhibited pulmonary granuloma formation by 74% and decreased levels of lung IL-5 and IL-13 transcripts compared with those in animals given control Ig by 20- and 5-fold, respectively, while anti-B7-1 administration has no effect. Anti-B7-2 treatment blocked CD4 cell gene expression of IL-4, IL-5, and IL-13, but had no effect on IFN-gamma or IL-10 in animals inoculated with S. mansoni ova, larvae from the filarial helminth Brugia malayi, or CFA. Anti-B7-1 administration had no effect on CD4 cell transcript levels of IL-4 and IL-5, but inhibited IFN-gamma in mice inoculated with ova. Similar effects of anti-B7-2 on CD4 cell cytokine expression were observed in IL-4 knockout mice, indicating the existence of an alternative pathway for induction and/or expression of these cytokine genes. These findings suggest a possible role for anti-B7-2 in the therapy of infectious and atopic diseases in which immunopathologic reactions are mediated by selected Th2 cytokines.

Defective entry of herpes simplex virus types 1 and 2 into porcine cells and lack of infection in infant pigs indicate species tropism

We have determined if a defect at entry of the human pathogen herpes simplex virus type 1 (HSV-1) into cultured porcine cells extends to HSV-2 and if the poor susceptibility of porcine cells for these viruses is indicative of in vivo species tropism. HSV-1 replicates poorly in swine testis (ST) and other porcine cells which lack a functional non-heparan sulphate receptor(s) required for virus entry. By several criteria, ST cells resist infection by either HSV-1 or HSV-2. Infection can be restored if normal entry is bypassed by PEG-mediated virion-cell membrane fusion. Neither HSV serotype infects, replicates or produces clinical symptoms in infant pigs. No virus was isolated from any of multiple sites and seroconversion did not occur. The in vitro defect in porcine cells blocking HSV entry correlates with, and is likely to be at least partly responsible for, in vivo resistance of pigs to infection.

Prospects for elimination of leprosy in India by 2000 AD

Data regarding the trends of new-case detection rates of leprosy for India as a whole, for the State of Andhra Pradesh, and for Srikakulam district in Andhra Pradesh were generated and projected up to 2000 AD. The prevalence rate by 2000 AD was worked out based on these new -case detection rates. The projections show that at the current slowly declining trend of new-case detection, with 20% MB cases among the newly detected cases and the current mean duration of treatment, the elimination goal of leprosy by 2000 AD, could possibly be achieved at Srikakulam district level only, where the MDT project has been under implementation for over ten years, but not at the State or country levels. The achievement of elimination goal should be possible in other geographic units also if the duration of disease could be shortened to one month or less, for both paucibacillary and multibacillary types of leprosy.

Deformity incidence in leprosy patients treated with multidrug therapy

The records of 2,285 (2,007 paucibacillary (PB) and 278 multibacillary (MB)) cases of leprosy which were declared as released from treatment (RFT) after multidrug therapy (MDT) and under surveillance as per the National Leprosy Eradication Programme (NLEP) guidelines in the rural field practice area of Central Leprosy Teaching & Research Institute (CLTRI), Chengalpattu, between September 1986 and September 1993 were analyzed for collecting data on the incidence of deformity. Of the 2,285 cases 2,053 (1,947 PB and 106 MB) did not have deformity at the commencement of treatment. Three MB cases and one PB case out of the 2,053 developed deformity (all grade II) during the course of treatment. No patient developed deformity during surveillance. Thus the deformity incidence in the population of patients was 0.681 per 1000 person-years of observation. Age, sex, type of disease, prior dapsone monotherapy and nerve involvement at the commencement of treatment appear to influence the deformity incidence. The risk of development of deformity in patients treated with MDT appear to be very low and analysis of larger data sets is suggested to corroborate the above findings as the information would be useful for planning prevention and management of deformity services.

Swine testis cells contain functional heparan sulfate but are defective in entry of herpes simplex virus

Herpes simplex virus (HSV) enters and infects most cultured cells. We have found that swine testis cells (ST) produce yields of infectious HSV-1 up to four orders of magnitude lower than those of human embryonic lung (HEL) and HEp-2 cells because of a defect in virus entry. For ST cells, virus binding is reduced, DNA from input virus cannot be detected, and virus proteins are not synthesized. Polyethylene glycol treatment of ST cells after exposure to HSV allows viral entry, protein synthesis, and productive infection. Transfection of viral genomic DNA that bypasses the normal entry process produces similar yields of infectious virus from ST, HEL, and HEp-2 cells. Therefore, all three cell lines can support the HSV replicative cycle. Biochemical analyses and inhibition of sulfation by sodium chlorate treatment show that ST cells contain amounts and types of heparan sulfate (HS) similar to those of highly susceptible cells. HSV infection of sodium chlorate-treated HEL and ST cells indicates the presence of a second, non-HS receptor(s) on susceptible HEp-2 and HEL cells that is missing, or not functional, on poorly susceptible ST cells. We conclude that ST cells are defective in HSV entry, contain functional HS, but lack a functional non-HS receptor(s) required for efficient HSV-1 entry. Further, ST cells provide a novel resource that can be used to identify, isolate, and characterize an HSV non-HS receptor(s) and its role in the entry and tropism of this important human pathogen.

Cell-mediated immune responses to sporozoites and macroschizonts of Theileria annulata

The nature of cell-mediated immune (CMI) responses was studied in cross-bred bovine calves, immunised by attenuated and allogeneic macroschizonts of Theileria annulata. The CMI responses were also investigated in calves, destined to survive or die of tropical theileriosis (Theileria annulata) induced by a virulent dose of sporozoites or macroschizont-infected lymphoblasts. Calves suffering fatal theileriosis showed poor CMI response. Microcytotoxicity assay revealed an enhanced population of specific cytotoxic cells amongst the peripheral blood lymphocytes (PBL) of calves resolving the infection successfully. The E rosette assay showed proliferation of T cells and the assay for macrophage migration inhibition factor (MIF) demonstrated antigen sensitised cells in the PBL. Calves, immunised by allogeneic and attenuated macroschizont-infected lymphoblasts or those recovering from virulent macroschizont-induced infection, showed protective CMI responses with patterns similar to those appearing after non-fatal sporozoite infection.

The localization of indium-111-leukocytes, gallium-67-polyclonal IgG and other radioactive agents in acute focal inflammatory lesions

A variety of radioactive agents, injected directly intravenously have demonstrated foci of inflammation by gamma camera imaging, avoiding the in vitro preparation of labeled leukocytes. This study sought to find out if any of these agents mimicked the biodistribution in abscesses and non-target organs of labeled mixed leukocyte suspensions. Eight different agents were compared with 111In-oxine labeled leukocytes in an acute soft tissue E. coli abscess and an acute arthritic lesion in 24 dogs one day after intravenous administration. These included 67Ga-citrate, human and canine polyclonal immunoglobulin (IgG), rabbit anti-dog polyclonal IgG, serum albumin, monoclonal antibody TNT-1 F(ab')2 against nuclear antigens, 57Co-porphyrin and serum albumin nanocolloid. None of these agents achieved abscess concentrations approaching those obtained with labeled leukocytes, and their abscess/blood and abscess/muscle concentration ratios were considerably lower. No statistically significant differences were found between the different radiolabeled proteins evaluated. The abscess concentration of 99mTc-nanocolloid was much lower than that of other agents, and the results with the oldest agent, 67Ga-citrate, were disappointing in these acute experiments.

Age-dependent covalent changes in MP18 from bovine lens membrane

Peptide antisera made against the putative MP18 sequence recognizes an 18-kilodalton protein on western blots of bovine lens membrane. These peptide antisera were used to investigate possible age-related changes in the MP18 molecule in membrane fractions from newborn and adult bovine lenses. Western blot analysis of membrane fractions with peptide antisera to sequences 45-50 (anti-45), 113-129 (anti-113), and C-terminus 169-173 (anti-Ct) showed similar patterns. All three antisera reacted more strongly with MP18 from membrane prepared from newborn lenses than with corresponding preparations from the adult lens. Binding ratios of anti-45 to anti-Ct showed a statistically significant difference between cortex and nucleus of newborn lenses (P less than 0.02) and between cortex of newborn and cortex of adult lenses (P less than 0.001). Differences in binding ratios of anti-113 to anti-Ct were the most striking, with anti-113 unable to detect MP18 in membrane preparations from adult lenses. Collectively, these results confirmed the putative sequence of MP18 and demonstrated covalent changes in this molecule during the process of aging in the normal bovine lens.

Immunoprophylaxis against Theileria annulata with protein from plasma membrane of infected lymphoblasts

Cross-bred (Bos taurus male x Bos indicus female) calves were protected against the homologous sporozoite-induced challenge of Theileria annulata when immunised with protein from the plasma membrane of macroschizont-infected lymphoblasts of allogeneic origin. However, such protection was parasite-strain specific with the plasma membrane originating from lymphoblasts infected and transformed by the same isolate of T. annulata sporozoites. No protection ensued when the infected lymphoblasts and sporozoites were from immunologically different isolates of T. annulata. There was enhanced proliferation of cells and evidence for lymphokine, originating from antigen-sensitised lymphocytes, demonstrable as macrophage migration inhibition factor in peripheral blood lymphocytes of the calves immunised by plasma membrane protein and challenged by sporozoites of homologous origin.

Comparison of different radioactive renal agents in cisplatin-induced tubular toxicity in rats

The efficacy of five different radiodiagnostic agents for detecting renal tubular dysfunction induced with cisplatin in rats was compared to controls. Diethylenetriaminepentaacetic acid (DTPA) labeled with 99mTc or 111In was administered simultaneously with each of the other four agents [99mTc]glucoheptonate, [99mTc]dimercaptosuccinic acid, [131I]hippuran and [111In]lysozyme) as a standard to normalize for differences in functional impairment from animal to animal from the same dose of cisplatin. The 2-hr plasma clearance and computer-generated 2- to 3-min uptake in the two kidneys with [99mTc]dimercaptosuccinic acid were significantly inferior to similar measurements with the other agents in differentiating abnormal from normal function. The 2-hr uptake of [99mTc]glucoheptonate and [111In]lysozyme proved of no value in this differentiation. The late renal retention of [99mTc]dimercaptosuccinic acid well separated the cisplatin from control rats, but the greatest difference was observed by the 2-hr uptakes of [131I]hippuran and DTPA.

Evaluation of cyclosporine nephrotoxicity in rats with various renal radioactive agents

The efficacy of different radiodiagnostic agents for demonstrating the decline in renal function from cyclosporine (CyA) nephrotoxicity was assessed in rats receiving a standard dose of the drug for 2 wk, compared with control rats. The agents included [99mTc]DTPA, [131I]hippuran, [111In]lysozyme, [99mTc]glucoheptonate (GHA), [99mTc]dimercaptosuccinate (DMS) and [111In]aminated dextran (amdex). A small dose of [99mTc]- or [111In]DTPA was administered simultaneously to normalize the results for variations in drug response from one animal to another. There were statistically significant differences in the detectability of the renal functional impairment by plasma clearance, early and 2-hr renal uptake among the different agents. However, none was clearly superior to DTPA. This conclusion is consistent with previous studies which showed a parallel decline in glomerular filtration rate (GFR) and effective renal plasma flow in acute CyA toxicity probably due primarily to vasoconstriction.

Thrombus imaging with indium-111 and iodine-131-labeled fibrin-specific monoclonal antibody and its F(ab')2 and Fab fragments

We have previously reported successful imaging of fresh (2-4 hr old) and aged (1-5 days old) canine thrombi with 131I-labeled intact monoclonal antibody (MAb) specific for fibrin. We now report thrombus imaging with 131I-labeled F(ab')2 and Fab and 111In-labeled intact MAb, F(ab')2, and Fab. Indium-111-labeled F(ab')2 proved to be the best imaging agent due to less nonspecific binding in the liver than whole IgG. Image quality was improved by the higher administered dose permissible with 111In and its better physical characteristics for imaging, compared to 131I. Immunofluorescence of fresh human histologic sections showed intact MAb and F(ab')2 binding to thrombi, pulmonary emboli, and atherosclerotic plaques, strengthening the feasibility of clinical thrombus imaging.

Failure of amantadine hydrochloride to alter immune responses in the experimental allergic encephalomyelitis model of neuroautoimmune disease

Amantadine hydrochloride has been reported efficacious in the symptomatic management of patients with multiple sclerosis (MS). To characterize further the potential effects of amantadine in MS, we studied the drug's effect on immunological parameters in the experimental allergic encephalomyelitis (EAE) model. Nine Lewis rats were used; 3 served as controls and 6 were EAE-induced. Three of the EAE-induced rats received amantadine (AMT) (0.3 g/kg/day) at the onset of EAE symptoms. Sera were collected post-AMT treatment and assayed for antimyelin basic protein antibody (anti-MBP) and 2'3'-cyclic nucleotide 3'-phosphohydrolase activity (CNP). The mean differences in the immunological parameters between treated and nontreated EAE-induced groups were not significant. These findings fail to demonstrate a specific effect of amantadine on immunologic responses tested in the EAE model, and do not support the notion that the effects of amantadine in MS are linked to basic alterations in immune responses.

Displacement chromatography of biomolecules

Displacement chromatography was used for the preparative-scale separation of peptides, antibiotics, and proteins. The feed components were both purified and concentrated during the separation processes. The components of a peptide mixture were separated on a reverse-phase analytical column using 2-(2-butoxyethoxy) ethanol as the displacer. The use of organic modifiers in the carrier along with an elevated column temperature of 45 degrees C enabled the efficient separation of relatively hydrophobic peptides by displacement chromatography. In addition, the throughput of the process was significantly increased by carrying out the separation at an elevated flow-rate with no adverse effect on product purity. The antibiotic cephalosporin C was isolated from impurities in a fermentation broth using 2-(2-butoxyethoxy)ethanol as the displacer along with a step change in column temperature. The proteins cytochrome c and lysozyme were purified on a weak cation-exchanger column using cationic polymers as the displacers. While polymers of 60 and 20 kilodaltons were both found to be good displacers for these proteins, only the lower molecular weight polymer was readily removed from the column by standard regeneration techniques.

99mTc-HM-PAO for leukocyte labeling--experimental comparison with 111In oxine in dogs

99mTc-hexamethylpropylene amine oxime d,l diastereoisomer (HM-PAO), developed as a diffusible brain imaging agent, labels leukocyte suspensions in saline with an efficiency of 80% using 1-200 micrograms quantities. In dogs, the recovery and survival of reinjected cells in the bloodstream resemble those of 111In-oxine labeled cells at least for several hours. Images in control animals at 18 h show the spleen, liver, marrow, and bladder, minimal pulmonary activity and some gastrointestinal activity. Induced E. coli abscesses and joint inflammatory lesions in dogs are shown on 18 h images. This complex appears promising as an agent for abscess detection in humans. However, strict quality control of this agent is necessary, and it must be used immediately after the 99mTc complex is formed for labeling cells.

Imaging fresh venous thrombi in the dog with I-131 and In-111 labeled fibrin-specific monoclonal antibody and F(ab')2 fragments

The authors report success in imaging thrombi using labeled monoclonal antibody or antibody fragments. An In-111 labeled antibody fragment appears to be the best imaging agent studied to date.

Cross-reaction among four isolates of Theileria annulata from India

A close identity in virulence and cross-protection of four isolates of Theileria annulata was observed when infection was produced in naive, crossbred (Bos taurus male X B. indicus female) male calves. The evidence that strains of T. annulata in India differ in virulence and immunogenicity is equivocal at present.