Tropical spastic paraparesis associated with human T lymphotropic virus type I in an east African naturalised in Sweden

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Streptococcal protein G: a sensitive tool for detection of antibodies to human immunodeficiency virus proteins in Western blot analysis

Protein G is a cell wall protein of group C and G streptococci which binds human IgG antibodies of all four subclasses with high affinity. This property of the molecule was utilized to develop a sensitive Western blot assay to detect antibodies against HIV proteins in patient sera.

Absence of host-cell influence on binding specificity of herpes simplex virus type 1 induced Fc receptor

Herpes simplex virus (HSV) infected cells express on their surface a receptor with affinity to the Fc portion of immunoglobulin G (IgG). The influence of the infected host cell on the specificity of the receptor was investigated with radiolabeled human IgG Fc fragment and four animal IgGs (rabbit, dog, cow, and rat) and eight human and animal (primate, rabbit, dog, cow, and rat) fibroblastoid and epithelioid cell lines. Human IgG Fc, rabbit IgG and cow IgG bound to all cell lines infected with HSV type 1 strain F (HSV-1 F), whereas dog IgG and rat IgG did not bind to any of these cells. The same binding pattern was seen when two additional HSV-1 strains infected rabbit epithelial (GMK AH1) cells. The results support the view that the specificity of the HSV Fc receptor is mainly under viral control and not primarily influenced by the species of the host cell.

Pediatric gastroenteritis in primary care and in hospitalized patients

One-hundred and fifty-seven consecutive children below seven years of age (primary care n = 48, hospitalized patients n = 109) with acute gastroenteritis of assumed infectious origin were studied. Rotavirus was demonstrated by electron microscopy of faeces in 44% of all patients. The occurrence of rotavirus among patients in primary care, 15%, was significantly lower than among hospitalized patients, 57% (p less than 0.01). Adenovirus was isolated in six per cent and enterovirus in two per cent of the patients with no differences between the two groups. Yersinia enterocolitica and Campylobacter jejuni were demonstrated in each three per cent. Salmonella and Shigella spp. or Giardia lamblia were not found in any cases. Thus the cause of gastroenteritis was established in 58% of the patients. This figure was lower among patients in primary care (27%) than among hospitalized patients (72%), a difference mainly due to the high occurrence of rotavirus in the latter group. Clostridium difficile was recovered in 20 cases (12%), eight of which harboured one more enteropathogenic agent. Cultures from the nose and throat revealed Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis or group A, C and G streptococci in 58% of the patients with no differences regarding the occurrence of rotavirus in faeces. Neither Clostridium difficile nor respiratory tract pathogens were found to play a role in causation of gastroenteritis in the children investigated.

Differential pattern of oncogene and beta-actin expression in leukaemic cells from AML patients

The presence of mRNA hybridizing to five oncogene (fos, mos, myc, sis, abl) and a beta-actin probe(s) was studied with a semiquantitative dot-blot procedure in eight AML patients. Around 10(7) leucocytes, corresponding to 1-10 ml blood, sufficed for the analysis. Each patient, regardless of the FAB group, exhibited a distinct pattern of oncogene or beta-actin expression. Especially strong signals were obtained with the beta-actin probe in two patients and with the fos probe in three patients. The findings underscore the heterogeneity of AML, either present from the first step towards malignancy or arising during the progression of the disease. The pattern of oncogene expression in leukaemic cells studied in routine blood samples may become an additional means for classification and follow-up of AML patients.

Anti-herpes simplex type 1 activity in IgG subclasses produced systemically and intrathecally in patients with herpes encephalitis

The role of the humoral immune response in herpes simplex encephalitis (HSE) is largely unknown. The finding that herpes simplex virus type 1 (HSV 1) induced IgG Fc receptor binds to all IgG subclasses except IgG 3 prompted an investigation of anti-HSV activity in IgG subclasses from serum and cerebrospinal fluid (CSF) in ten patients with proven or highly probable HSE by means of a monoclonal antibody IgG subclass-specific solid-phase radioimmunoassay (SPRIA). In contrast to serum, CSF contained no or low anti-HSV IgG titres during the first 2 weeks of disease in five of seven patients tested. The IgG titres rose thereafter for at least 4 weeks after the start of illness and remained high in both serum and CSF up to 393 days. The anti-HSV IgG subclass distribution in serum was IgG 1 (ten of ten), IgG 2 (two of ten), IgG 3 (six of ten), and IgG 4 (six of ten). Two patients had a simultaneous anti-HSV IgG 3 and IgG 4 response. With the exception of one patient lacking anti-HSV IgG 4 and two patients lacking anti-HSV IgG 2, the subclass distribution in CSF was the same as in serum. The anti-HSV subclass distribution in sera from ten seropositive patients without evidence of recent herpes infection did not differ from that of the HSE patients, except that five of ten patients had simultaneous anti-HSV IgG 3 and IgG 4 responses. Thus we could not correlate the anti-HSV subclass response in patients with HSE with the subclass preference of the HSV-induced Fc receptor.

Hepatitis B virus-DNA in the serum of patients followed-up longitudinally with acute and chronic hepatitis B

Sera from 79 patients with acute self-limiting hepatitis, 17 patients with acute hepatitis B evolving into chronic HBsAg carriership, and 43 chronic HBsAg carriers without a history of acute hepatitis were analyzed for presence of hepatitis B virus (HBV)-DNA by a molecular hybridization technique. In acute self-limiting hepatitis, HBV-DNA was cleared within a few weeks after the onset of clinical symptoms. The longest period of DNA positivity observed in this group was 42 days. In 29 of 52 patients HBV-DNA was cleared before HBeAg disappeared. Among 17 patients who became chronic HBsAg carriers, HBV-DNA was present for more than 6 months in all but one. Most of the HBsAg carriers eventually cleared HBV-DNA. The DNA clearance frequently preceeded the conversion of HBeAg to anti-HBe. Thus, in many patients there was a transitional period with HBeAg but without HBV-DNA. HBV-DNA was found to be a better index of impending chronicity than HBeAg since persistence of HBeAg for more than 42 days was noted in 10% of the patients who nevertheless cleared HBsAg within 6 months. By that time all those patients had turned negative for HBV-DNA. On the other hand, in 16 of the 17 patients who became chronic carriers of HBsAg, HBV-DNA as well as HBeAg persisted for more than 6 months. The present results also suggest that infectivity in acute hepatitis B is a feature mainly of the presymptomatic and early symptomatic period.

Specificity of Fc receptors induced by herpes simplex virus type 1: comparison of immunoglobulin G from different animal species

Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind the Fc portion of immunoglobulin G (IgG). Of the four human IgG subclasses, the HSV-1 Fc receptor, like staphylococcal protein A, binds to all except IgG3. In this paper, we describe the binding of a number of animal IgG and IgG subclass molecules to HSV-1-infected cells and compare this binding to that of protein A. Although only few representatives from each animal order were tested, we found that IgG from Carnivora and Rodentia did not bind or bound only slightly to the HSV-1 receptor, whereas IgG from Primates, Lagomorpha, and Artiodactyla bound well. This pattern was clearly different from the species spectrum of IgG binding of protein A. Differences between the two receptors were also found when animal IgG subclasses were tested. The pronounced differences in affinity for the HSV-1 Fc receptor between immunoglobulins from, for example, mouse and rabbit may influence the interpretation of animal studies with this virus.

Antibodies to human adult T cell leukaemia virus type I associated antigens in Swedish leukaemia patients and blood donors

Antibodies to antigens associated with human T cell leukaemia virus type I (HTLV I) in Swedish adult leukaemia patients and blood donors were sought with a sensitive screening test using membrane antigen prepared from virus producing cells (MA-ELISA). Four persons (one ALL, one AML and two healthy blood donors) out of 483 persons tested reacted in the test. However, they were negative in the more specific anti-p19 and anti-whole virion ELISA tests. The prevalence of sera with definite anti-HTLV I activity seems to be very low in Sweden. The finding of four MA-ELISA positive persons needs further investigation.

HTLV in Sweden: antibodies to HTLV I antigens in experimental monkeys and their caretakers

252 monkeys kept at 4 different Swedish universities and laboratories for experimentation were screened for antibodies to HTLV I associated antigens by means of a sensitive membrane antigen enzyme immunoassay (MA-ELISA). 17/185 Macaca fascicularis, 1/56 M. mulatta, 0/1 Cercopithecus aetiops and 0/10 Saimirii squiureus had antibodies. All of 11 MA-ELISA positive animals which were subjected to further testing were also positive in a competition assay for anti-HTLV p19 antibodies and in an anti-whole virion enzyme immunoassay. One colony of 32 M. fascicularis monkeys from the Philippines contained 7 antibody-positive animals. Except for one M. fascicularis which suffered from a chronic dermal lesion, major disease was not observed in any of the antibody-positive animals. None of 28 animal caretakers or experimenters, of which several had been repeatedly exposed to blood from antibody-positive animals, had antibodies measurable by the MA-ELISA. The contagiosity for humans of the majority of the antibody-positive monkeys thus appears to be relatively low. We conclude that the presence in Sweden of HTLV I antibody-positive animals probably does not constitute a great health risk. However, we consider it appropriate that antibody-positive animals should be handled with special care.

Etiology of community-acquired pneumonia in patients requiring hospitalization

The etiology of community-acquired pneumonia was studied in 127 patients with roentgenologically verified pneumonia who needed hospitalization. Etiology was determined on the basis of a positive blood culture and/or a significant antibody titer increase. Streptococcus pneumoniae was the probable etiological agent in 69 patients, nontypeable Haemophilus influenzae in five patients, Streptococcus pyogenes in two patients, and Legionella pneumophila and Staphylococcus aureus in one patient each. Evidence of Mycoplasma pneumoniae infection was found in 18 patients and of Chlamydia psittaci infection in three patients. Influenza virus type A was the cause of infection in 15 patients. One patient had infection with influenza virus type B, one patient with parainfluenza virus type 1, and three patients with respiratory syncytial virus. In 20 patients there was evidence of infection with more than one microorganism. No etiological agent was found in 27 patients. Since Streptococcus pneumoniae was the predominant etiological agent penicillin should be drug of first choice in patients with pneumonia who need treatment in hospital. In young adults, however, the high frequency of Mycoplasma pneumoniae infection would justify the use of erythromycin or doxycycline as drug of first choice.

Immunoglobulin G antibodies binding to a synthetic peptide deduced from the nucleotide sequence of the env gene of HTLV I in patients with leukemia and rheumatoid arthritis, HLA sensitized persons and blood donors

A synthetic pentadecapeptide preparation, env 406-420, with an amino acid sequence deduced from the envelope glycoprotein gene of human T cell leukemia virus type I (HTLV I), was used as the antigen in an enzyme immunoassay for immunoglobulin G antibodies, exploring its usefulness for seroepidemiological purposes. The frequency of reactivity in the test groups, presented in decreasing order was: patients with rheumatoid arthritis; multitransfused nonleukemic patients; Japanese cases of adult T cell leukemia (ATL); HLA sensitized persons; Swedish cases of adult acute leukemia; and Swedish blood donors. Three American cases of ATL and 12 HTLV I seropositive monkeys did not react. In RF positive sera from patients with rheumatoid arthritis, no quantitative correlation between RF activity and anti-env 406-420 activity was seen. Anti-env 406-420 positive sera did not react or reacted only weakly with four control peptide preparations with different amino acid sequences. The experience with oligopeptide serology still is limited. Our results illustrate that unexpected cross-reactions which are hard to interpret can occur. Although absorption experiments indicated an HTLV I specific component of the reactivity, antibodies against epitopes of allo- and auto-immune specificity may also have participated.

Human immunoglobulin class and subclass specificity of Fc receptors induced by herpes simplex virus type 1

Herpes simplex virus is known to induce an immunoglobulin-binding cell surface receptor in infected cells that utilizes a nonimmune mechanism. In the present paper, we report the immunoglobulin class and subclass specificity of this receptor. Of the human immunoglobulins G(IgG), IgA, IgM, and IgD, as well as the structurally related beta2 microglobulin, only IgG and its Fc portion exhibited an increased binding to herpes simplex virus-infected cells versus uninfected control cells. The IgG subclass specificity of the Fc receptor was studied in 37 radioiodinated IgG myeloma proteins representing all four subclasses. We found that IgG3 myeloma proteins did not bind to herpes simplex virus-infected cells to a greater extent than to uninfected cells. On the contrary, proteins belonging to the other subclasses exhibited an increased binding to herpes simplex virus-infected cells of the following relative magnitude: IgG4 greater than IgG1 greater than or equal to IgG2. This increment of binding could be abolished by addition of a large excess of human IgG Fc fragment. Evidence for the existence of a variable herpes simplex virus-specific binding ability between myeloma proteins belonging to the same IgG subclass was also obtained. Furthermore, we tested two other herpes simplex virus type 1 strains with a limited number of myeloma proteins with very similar results as with the herpes simplex virus type 1 F strain. Several sources of experimental artefacts were controlled, including the state of aggregation of the test proteins, the functional integrity of the Fc portion before and after radioiodination, and the subclass assignments. The implications for the biological role of the Fc receptor of herpes simplex virus are discussed.

Determination of rubella immunity by latex agglutination: its place in clinical routines

The sensitivity and specificity of Rubascan (r) (RSC), a new latex agglutination test for rubella antibodies, was compared with those of the single radial hemolysis (SRH) and hemagglutination inhibition (HI) tests. We found RSC to have a sensitivity versus SRH and HI of 90-95% and 70-72%, respectively. RSC had a specificity versus SRH and HI of 97-100% and 96-100%, respectively. However, only 4/7 titer rises from cases of acute rubella or rubella vaccinations were clearly discernible in RSC. Moreover, only 2/10 anti-rubella IgG and IgM containing sera were RSC positive after protein A absorption although 10/10 were still HI positive. Additionally, the HI-positive IgM fractions from a sucrose density gradient centrifugation of an anti-rubella IgM containing serum were negative. We conclude that IgM reacts differently from IgG in RSC. We consider RSC a potentially useful reagent for determination of immunity in non-acute situations, and in non-pregnant persons like in pre-employment testing. This could be performed by relatively untrained personnel. On the other hand a rubella immunity test in pregnant women or in acute rubella should preferably be truly quantitative, in order to allow precise titer comparisons. In these cases, the interpretation of tests may require experience, and they should be performed at more specialized laboratories.

Viral antibody screening system that uses a standardized single dilution immunoglobulin G enzyme immunoassay with multiple antigens

We present an enzyme-linked immunosorbent assay (ELISA) system for the simultaneous determination of immunoglobulin G antibodies directed against several viruses. Antibodies to up to eight different viruses could be determined for three different sera on one microtitration plate. After subtraction of the absorbance values obtained with the control antigens, the viral antigen absorbancies were expressed as percentages of the absorbance obtained with a pooled immunoglobulin standard. This value, the relative antibody activity, was rapidly calculated by means of a computer directly connected to the ELISA photometer and was stored on magnetic disks, thereby facilitating seroepidemiological studies. The reproducibility of the relative antibody activity was calculated to at best +/- 3.6% (standard deviation) in an intraassay test and to at worst +/- 20.4% (standard deviation) in an interassay test. Each serum was analyzed only at a dilution of 1/75. The sensitivity of this single-dilution ELISA (SD-ELISA) method for the detection of titer rises was compared with those of conventional methods, mostly complement fixation but also hemagglutination inhibition. A total of 142 of 155 (92%) paired sera showing fourfold complement fixation or hemagglutination inhibition rises also showed significant results in SD-ELISA. A total of 22 of 57 (39%) significant relative antibody activity rises were significant in complement fixation or hemagglutination inhibition. Overall, up to twice as many significant titer rises could be detected with SD-ELISA. Most of these seemed to have a sound correlation with clinical data. The specificity of SD-ELISA was found to be similar to that of complement fixation, with some cross-reactions occurring between herpes simplex and varicella-zoster virus antigens and between parainfluenza viruses. We have found SD-ELISA to be a valuable clinical virological tool that supplements conventional serology.

Glycosphingolipids of a green monkey kidney cell line (GMK AH-1). Evidence for a novel pentaglycosylceramide based on globotetraosylceramide

Total non-acid glycolipid fractions have been isolated from GMK AH-1 cells grown in fetal calf serum and in horse serum. For comparison, glycolipids were also prepared from green monkey (Cercopithecus aetiops) kidney and from fetal calf serum. The major glycolipids from GMK AH-1 cells grown in fetal calf serum were isolated by silicic acid column chromatography and preparative thin-layer chromatography. These fractions were characterized mainly by thin-layer chromatography, mass spectrometry and gas chromatography. The structures of the glycolipids isolated were proposed as: Glc1 leads to 1Cer, Gal1 leads to 1Cer, Gal1 leads to 4Glc1 leads to 1Cer, Gal1 leads to 4Gal1 leads to 4Glc1 leads to 1Cer, GalNAcl leads to 3Gal1 leads to 4Gal1 leads 4Glc1 leads to 1Cer. In addition, a novel pentaglycosylceramide with the probable structure Ga1 beta 1 leads to 3GalNAc beta 1 leads to Gal alpha 1 leads to 4Gal beta 1 leads to 4Glc beta 1 leads to 1Cer was also present. THe ceramides contained mainly dihydroxy 18:1 long-chain base in combination with non-hydroxy 16:0-24:0 fatty acids. Small amounts of trihydroxy 18:0 long-chain base and hydroxy 22:0-24:0 fatty acids were also present in the mono- and diglycosylceramide fractions. The glycolipid patterns of GMK AH-1 cells grown in fetal calf serum or horse serum were identical. The pentaglycosylceramide present in the cultured cells could not be detected with certainty in the kidney tissue. The uptake of this glycolipid from the culture medium is unlikely as it seems to be lacking in calf serum.

O-glycosidic carbohydrate-peptide linkages of Herpes simplex virus glycoproteins

Electrophoretically purified HSV-specified glycoproteins with radiolabelled carbohydrates were subjected to mild alkaline borohydride treatment (0.5 M NaOH and 0.5 M NaBH4). The treatment liberated significant amounts of the labelled oligosaccharides. The latter demonstrated molecular weights of about 3,000 as determined by gel filtration. The glycoproteins involved probably belong to the gA/gB complex or gC. The results suggest that HSV specified glycoproteins contain oligosaccharides linked with an O-glycosidic bond to a threonine or serine residue of the polypeptide.

Intrauterine varicella: a report of two cases associated with hyper-A-immunoglobulinemia

Varicella during pregnancy may occasionally harm the fetus. This report described one case of congenital varicella syndrome and another of infantile herpes zoster after maternal varicella in the 16th and 29th week of pregnancy, respectively. A remarkable finding was that both mothers and infants had raised levels of serum IgA. This suggests that varicella is prone to lead to congenital disease in infants of pregnant women with an immunologic, perhaps genetically determined abnormality.

Snyder-Theilen feline sarcoma virus P85 contains a single phosphotyrosine acceptor site recognized by its associated protein kinase

Cells nonproductively transformed by a variant of the Snyder-Theilen strain of feline sarcoma virus (FeSV) expressed an 85,000-dalton polyprotein (P85) with associated tyrosine-specific protein kinase activity. We identified within this polyprotein a single tyrosine acceptor site for its enzyme activity. This acceptor site, as well as two serine phosphorylation sites localized with the p12 structural component of Snyder-Theilen FeSv P85, was phosphorylated in cells nonproductively transformed by Snyder-Theilen FeSv. In contrast, infection by Snyder-Theilen FeSV transformation-defective mutants resulted in phosphorylation only of the two serine acceptor sites, indicating phosphorylation of the tyrosine acceptor site to be transformation specific. In addition, we describe in vitro labeling conditions, using unfractionated cell extracts, which resulted in preferential phosphorylation of the single Snyder-Theilen FeSV tyrosine-specific acceptor site.

Differences in mechanisms of transformation by independent feline sarcoma virus isolates

The Gardner and Snyder-Theilen isolates of feline sarcoma virus (FeSV) have previously been shown to encode high-molecular-weight polyproteins with a transforming function and an associated tyrosine-specific protein kinase activity. Cells transformed by these viruses exhibited morphological alterations, elevated levels of phosphotyrosine, and a reduced capacity for binding epidermal growth factor. In addition, polyproteins encoded by both of these FeSV isolates bound to, and phosphorylated tyrosine acceptor sites within, a 150,000-molecular-weight cellular substrate (P150). McDonough FeSV-transformed cells resembled Gardner and Snyder-Theilen FeSV transformants with respect to morphological changes and a reduced capacity for epidermal growth factor binding. in contrast to the other two FeSV isolates, however, McDonough FeSV encoded as its major translational product a high-molecular-weight polyprotein with probable transforming function but without protein kinase activity detectable under similar assay conditions. Moreover, total cellular levels of phosphotyrosine remained unaltered in McDonough FeSV-transformed cells, and the major McDonough FeSV polyprotein translational product lacked binding affinity for P150. These findings argue for differences in the mechanisms of transformation by these independently derived FeSV isolates.

Involvement of a high-molecular-weight polyprotein translational product of Snyder-Theilen Feline sarcoma virus in malignant transformation

The previously described high-molecular-weight polyprotein major translational product of the Snyder-Theilen strain of feline sarcoma virus (FeSV) was shown to possess protein kinase activity with specificity for tyrosine acceptor sites. Cells transformed by Snyder-Theilen FeSV exhibited constitutively elevated levels of phosphotyrosine and a concomitant reduction in epidermal growth factor (EGF) binding sites. By endpoint cloning in microtiter plates, a number of transformation-defective (tf) mutants of the Snyder-Theilen strain of FeSV were isolated. Mink cells nonproductively infected by such mutants were morphologically nontransformed, failed to grow in soft agar, bound EGF as efficiently as control mink cells, and lacked rescuable transforming virus. Although the level of expression of the major viral polyprotein translational product in td mutant-infected clones was comparable to that of wild-type (wt) transformants, the polyprotein in mutant clones lacked detectable protein kinase activity and total cellular phosphotyrosine levels were not elevated significantly above control values. Of a large number of wt Snyder-Theilen FeSV-transformed mink cell clones isolated, the majority were found to revert to a nontransformed morphology upon continuous passage in cell culture. Such nontransformed variants, as well as a Gardner FeSV-transformed mink cell revertant, lacked detectable polyprotein expression and exhibited levels of phosphotyrosine and EGF binding similar to those of control mink cells. These findings provide strong evidence favoring the involvement of the Snyder-Theilen FeSV-encoded high-molecular-weight polyprotein and its associated tyrosine-specific protein kinase activity in transformation.