[HCV-serotype and IFN response]

The relation between HCV-serotypes and response to interferon (IFN) in 114 cases with chronic hepatitis C treated with IFN-alpha were studied. HCV-serotypes; two distinct subgroups (serotype 1 and 2) of hepatitis C virus defined by antibodies directed to the putative core protein, were examined by ELISA developed by Machida et al. 1) Of 33 cases with serotype 2, 20 were responders, whereas, only 5 of 35 cases with serotype 1 responded to IFN therapy. 2) Of 23 cases with HCV-genotype III, 18 (78.3%) responded to IFN. Moreover, 12 (85.7%) of 14 cases who had serotype 2 were responders. On the other hand, only 17 (21.0%) cases with genotype II and 4 (12.1%) cases with serotype 1 responded to IFN. HCV-serotyping as well as HCV-genotyping in cases with chronic hepatitis C seems to be important in predicting the response to IFN therapy.

Mechanisms involved in the inhibition of growth of a human B lymphoma cell line, B104, by anti-MHC class II antibodies

The mechanisms involved in the inhibition of growth of a human B lymphoma cell line, B104, by anti-MHC class II antibodies (Ab) were compared with those in anti-IgM Ab-induced B104 growth inhibition. Two anti-MHC class II Ab, L227 and 2.06, inhibited the growth of B104 cells, although 2.06, but not L227, needed to be further cross-linked with a goat anti-mouse IgG Ab (GAM) to show the effect. L227 induced an increase in intracellular free Ca2+ concentration ([Ca2+]i) from the intracellular pool and little or no protein tyrosine phosphorylation, phosphatidyl inositol turnover, or expression of Egr-1 mRNA, whereas 2.06 plus GAM induced an increase in [Ca2+]i from both the intracellular and, in particular, the extracellular pools. The inhibition of B104 cell growth induced by anti-MHC class II Ab was Ca(2+)-independent and not inhibited by actinomycin D or cyclosporin A, and cell cycle arrest at the G2/M interphase was not observed. These features are very different from those observed in B104 cell death induced by anti-IgM Ab. Neither DNA fragmentation nor the morphology of apoptosis was observed. These findings demonstrate that cross-linking of MHC class II molecules transduced the negative signals through intracellular mechanisms different from those present in the cross-linking of surface IgM.

Involvement of CD11b/CD18 in enhanced neutrophil adhesion by Fc gamma receptor stimulation

Neutrophils showed a rapid and transient adhesion to immunoglobulin G (IgG)-coated plates compared with their adhesion to bovine serum albumin (BSA)-coated plates: the adhesion reached a peak after 15 min of incubation and then gradually returned to almost the basal state in 60 min. The addition of monomeric IgG or anti-Fc gamma RII monoclonal antibody (mAb) (IV.3) suppressed the increase in adhesion, whereas anti-Fc gamma RIII mAb (3G8) was hardly effective, indicating that the interaction of Fc gamma R, especially Fc gamma RII, with coated IgG is involved in the process. Adhesion was also blocked by cytochalasin B, suggesting that functional actin filament structures are crucial. Protein kinase inhibitors, erbstatin and genistein, inhibited the adhesion in a dose-dependent manner. The adhesion was inhibited by anti-CD11b (M1/70) and anti-CD18 (MHM23, TS1/18) mAbs. Moreover, neutrophils from a patient with complete leukocyte adhesion deficiency syndrome did not show increased adhesion to IgG-coated plates. The adhesion of neutrophils to fibrinogen- and BSA-coated plates was also increased when Fc gamma R was stimulated in the fluid phase with soluble aggregated IgG, which was also inhibited by anti-CD11b mAb. Stimulation of neutrophil Fc gamma R with soluble aggregated IgG enhanced the expression of CD11b in concert with the enhanced adhesion. These data collectively suggest that stimulation via Fc gamma R evokes a tyrosine kinase-dependent and actin filament-dependent intracellular signal that enhances the specific and nonspecific adhesive activity of neutrophils, presumably through the activation of CD11b/CD18.

Hepatitis B virus subtypes and hepatitis C virus genotypes in patients with chronic liver disease or on maintenance hemodialysis in Indonesia

Hepatitis B surface antigen (HBsAg) and hepatitis C virus (HCV) RNA were surveyed in patients in Yogyakarta, Indonesia, and their subtypes and genotypes were determined by serological methods and polymerase chain reaction with type-specific primers, respectively. Of 149 patients with chronic liver disease including 24 with chronic hepatitis, 86 with liver cirrhosis, and 39 with primary hepatocellular carcinoma, HBsAg was detected in 40 (27%) and HCV RNA in 48 (32%); one patient was positive both for HBsAg and HCV RNA. Thus, the cause of chronic liver disease was not identified in 62 (42%) patients. Of 58 patients on maintenance hemodialysis, four (7%) were positive for HBsAg and 44 (76%) for HCV RNA. Subtype adw was found in 34 (74%) of 46 HBsAg samples and adr in five (11%); compound subtypes, such as adyw and adyr were detected in the remaining seven (15%). Among HCV RNA samples from 48 patients with chronic liver disease, 23 (48%) were of genotype II, 17 (35%) of genotype III and one (2%) of genotype V, in a distribution strikingly different from that of 44 samples from patients on maintenance hemodialysis, 39 (89%) of which were of genotype I and only one (2%) of genotype II. Genotypes were not classifiable in seven (15%) patients with liver disease and four (9%) patients on hemodialysis despite high HCV RNA titers in them all. These results indicate that different HCV genotypes prevail in patients with distinct diseases, as well as unclassifiable HCV genotypes in Indonesia.

Induction of eosinophilic granules, nonspecific esterase activity and CD14 expression in the human eosinophilic leukemia cell line, EOL-1

We examined the expression of eosinophilic granules, esterase activity and CD14 in a human eosinophilic cell line, EoL-1. Unstimulated EoL-1 cells were weakly positive for nonspecific esterase, but negative for surface CD14, and contained a few eosinophilic granule-positive cells. A combination of G-CSF and TNF-alpha increased the eosinophilic granule-containing cells, but failed to increase esterase activity or CD14 expression. IFN-gamma alone or in combination with TNF-alpha enhanced nonspecific esterase activity but failed to induce CD14 expression or increase eosinophilic granule-containing cells. dbcAMP increased eosinophilic granule-containing cells, nonspecific esterase activity and CD14 expression. Specific esterase activity was not detected in any circumstances. EoL-1 cells fractionated by density gradients or CD14 expression showed nonspecific esterase activity and CD14 expression in both the eosinophilic granule-positive and negative cell populations. Forskolin and butyrate had a synergistic effect on CD14 induction and protein kinase A was suggested to play a role in dbcAMP-induced CD14 expression. A protein kinase C activator, phorbol 12-myristate 13-acetate, did not increase eosinophilic granules, nonspecific esterase activity or CD14 expression in EoL-1 cells. The results show that EoL-1 cells can express nonspecific esterase and CD14, but the expression is not necessarily restricted to cells which have differentiated into the monocyte/macrophage lineage.

Hepatitis C virus infection in spouses of patients with type C chronic liver disease

OBJECTIVE

Survey for markers of hepatitis C virus (HCV) infection in spouses of patients with HCV-related chronic liver disease.

DESIGN

Cross-sectional clinical, serologic, and molecular biological study of spouses of patients with HCV viremia and chronic liver disease.

SETTING

University and city hospitals.

PARTICIPANTS

Spouses (52 men and 102 women; mean age, 56 +/- 11 years) of 154 patients with HCV viremia (102 men and 52 women; mean age, 58 +/- 10 years), of whom 66 had chronic hepatitis, 49 had liver cirrhosis, and 39 had primary hepatocellular carcinoma.

METHODS

Tests for HCV-associated antibodies were done using a second-generation enzyme immunoassay and immunoassays with synthetic oligopeptides deduced from the HCV core gene. Hepatitis C virus RNA was detected by polymerase chain reaction with primers deduced from the 5'-noncoding region and HCV genotypes by reaction with type-specific primers deduced from the HCV core gene.

RESULTS

Hepatitis C virus-associated antibodies were detected in 42 (27%) spouses, of whom 25 were also positive for HCV RNA. Of 112 (73%) spouses without detectable antibodies, 2 had chronic liver disease. The development of markers of HCV infection in spouses increased with the duration of marriage, ranging from 1 to 60 years (30 +/- 11 years).

CONCLUSIONS

Spouses of patients with HCV viremia and chronic liver disease have an increased risk for acquiring HCV, which is proportional to the duration of marriage. They should be followed routinely for markers of HCV infection and liver disease.

Naturally occurring escape mutants of hepatitis B virus with various mutations in the S gene in carriers seropositive for antibody to hepatitis B surface antigen

Hepatitis B virus (HBV) DNA was extracted from sera of six carriers with hepatitis B e antigen as well as antibody to hepatitis B surface antigen and sequenced within the pre-S regions and the S gene. HBV DNA clones from five of these carriers had point mutations in the S gene, resulting in conversion from Ile-126 or Thr-126 of the wild-type virus to Ser-126 or Asn-126 in three carriers and conversion from Gly-145 to Arg-145 in three of them; clones with Asn-126 or Arg-145 were found in one carrier. All 12 clones from the other carrier had an insertion of 24 bp encoding an additional eight amino acids between Thr-123 and Cys-124. In addition, all or at least some of the HBV DNA clones from these carriers had in-phase deletions in the 5' terminus of the pre-S2 region. These results indicate that HBV escape mutants with mutations in the S gene affecting the expression of group-specific determinants would survive in some carriers after they seroconvert to antibody against surface antigen. Carriers with HBV escape mutants may transmit HBV either by donation of blood units without detectable surface antigen or through community-acquired infection, which would hardly be prevented by current hepatitis B immuneglobulin or vaccines.

Tyrosine phosphorylation of MB-1, B29, and HS1 proteins in human B cells following receptor crosslinking

Recent studies of murine and human B lymphocytes have shown that crosslinking of surface IgM (sIgM) and sIgD stimulates tyrosine phosphorylation of a set of proteins involved in signal transduction. We investigated tyrosine phosphorylation of the sIg-associated proteins MB-1 and B29, and p75HS1 (HS1), and the association of HS1 with MB-1/B29 heterodimers in normal human B cells and a human B lymphoma cell line, B104. Using immunoprecipitation with anti-phosphotyrosine antibodies (Abs) followed by immunoblotting with anti-MB-1 Abs, anti-B29 Abs or anti-HS1 Abs, we demonstrated that MB-1, B29 and HS1 were tyrosine-phosphorylated after sIgM or sIgD crosslinking. Immunoprecipitation with anti-B29 Abs followed by anti-HS1 Abs immunoblotting revealed that HS1 was associated with MB-1/B29 heterodimers after sIgM or sIgD crosslinking. The results showed that HS1 may play an important role in signal transduction through sIgM and sIgD on human B cells.

Contribution of hepatitis C virus to non-A, non-B fulminant hepatitis in Japan

To assess the contribution of hepatitis C virus to non-A, non-B fulminant hepatitis in Japan, we compared 10 major clinical features among 7 patients with type B fulminant hepatitis (type B group), 13 patients with non-A, non-B fulminant hepatitis with evidence of hepatitis C virus infection (type C group) and 10 patients without evidence of hepatitis C virus infection (NANB group). Duration from first symptom to coma and that from onset of jaundice to coma was significantly longer in the type C group (median = 39 and 25 days, respectively) and in the non-A, non-B group (median = 29 and 12 days, respectively) than in the type B group (median = 9 and 2 days, respectively) (p < 0.01). The maximum median AST level was significantly lower in the type C (1,689 U/L) and non-A, non-B groups (1,353 U/L) than in the type B group (5,780 U/L) (p < 0.05). Serum transaminase levels showed a single peak in six of seven of the type B patients, whereas they formed two or more peaks in all of the type C patients and in most of the non-A, non-B group (p < 0.05). Six of seven in the type B group, 6 of 13 in the type C group and 4 of 10 in the non-A, non-B group survived (p < 0.05). We found no significant difference in any of the 10 clinical features between the type C and non-A, non-B groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus variants from Nepal with novel genotypes and their classification into the third major group

Five isolates of hepatitis C virus (HCV) RNA from patients with chronic liver disease in Nepal were not classifiable into the known genotypes I/1a, II/1b, III/2a, IV/2b or V/3a using PCR with type-specific primers deduced from the HCV core gene. Their nucleotide sequences were determined for the 5'-terminal 1.5 kilobases and 3'-terminal 1.2 kilobases, covering 30% of the entire genome, and compared with each other and with reported sequences of HCV isolates of various genotypes. They were more similar to a reported HCV isolate (NZL1) of genotype V/3a (in 81.6 to 84.1% of their nucleotides and 85.7 to 88.7% of the deduced amino acid sequence) compared with the genotypes I/1a to IV/2b (in 69.3 to 74.7% and 72.3 to 77.4%, respectively). Hence they were considered to be variants of the third major group (group 3). The five HCV isolates shared 81.3 to 85.2% of nucleotide sequence and 85.4 to 89.3% of deduced amino acid sequence. Thus they were substantially different from each other. One of them was classified as genotype VI/3b due to an 88.2% similarity in nucleotide sequence to that of the reported HCV isolates of this genotype, whereas the remaining four were classified into provisional genotypes 3c, 3d, 3e and 3f. These HCV variants have evolved and remained in Nepal, and have not been observed in the other areas of the world.

Hepatitis B virus subtypes and hepatitis C virus genotypes in patients with chronic liver disease in Nepal

A total of 145 patients with chronic liver disease, including 20 with chronic hepatitis, 63 with cirrhosis and 62 with primary hepatocellular carcinoma from Nepal were tested for markers of hepatitis B virus or hepatitis C virus infection. HBsAg was detected in 57 (39%) and hepatitis C virus RNA in 12 (8%); the cause of liver disease was not known in the remaining 76 (52%). HBsAg was found in 5 (1.3%) of 379 normal controls, whereas hepatitis C virus-associated antibodies were detected in 13 (3.4%), none of whom was positive for serum hepatitis C virus RNA. Subtypes of 102 HBsAg samples, from patients and asymptomatic carriers, were adw in 35 (34%), adr in 4 (4%) and ayw in 48 (47%); the remaining 15 (15%) were of atypical subtypes such as ad, ay and a. Of 12 hepatitis C virus RNA samples, genotype I was detected in 1, genotype II in 5 and genotype V in 1; the remaining five samples were not to be classified by polymerase chain reaction with primers specific for genotypes I to V deduced from hepatitis C virus core sequences, despite high hepatitis C virus RNA titers in all of them. Sequences of 192 amino acids in the entire E1 region of unclassifiable hepatitis C virus isolates from five patients differed from each other in 17% to 23%, and varied from reported isolates of defined genotypes in 13% to 44%. These results indicate that atypical subtypes of hepatitis B virus and novel genotypes of hepatitis C virus would prevail in Nepal.

The entire nucleotide sequence and classification of a hepatitis C virus isolate of a novel genotype from an Indonesian patient with chronic liver disease

Three hepatitis C virus (HCV) isolates were obtained from patients with chronic liver diseases in Indonesia which were not classifiable into any of the genotypes I/1a, II/1b, III/2a, IV/2b or V/3a reported previously. The entire nucleotide sequence was determined for one HCV isolate (HC-G9); the remaining two isolates were of the same genotype based on a > 95% similarity within their partial sequences spanning 2927 nucleotides (nt). The HC-G9 genome consisted of 9440 nt including the 5' untranslated region of 341 nt, an open reading frame of 9033 nt coding for a polyprotein of 3011 amino acids and the 3' untranslated region of 66 nt (U stretch of 17 to 47 nt at the extreme 3' terminus excluded). It differed by 20 to 33% in nucleotide sequence from any of 14 HCV genomes of genotypes I/1a to IV/2b whose full-length sequences are known. By the unweighted pair-group method with arithmetic mean, HC-G9 was on a major branch (group 1) of the phylogenetic tree of HCV to which genotypes I/1a and II/1b belong. It is proposed, therefore, that the novel genotype for HC-G9 should be called 1c. A method was developed to identify genotype 1c by PCR with a primer deduced from the core gene that was specific to it. Since genotype 1c was detected in seven (15%) of 48 HCV RNA samples from Indonesian patients with chronic liver disease, but not in any of 1097 from other districts of the world, it appears to have evolved and remained in Indonesia. In addition to its epidemiological importance, the association of genotype 1c HCV with the severity of liver disease and its response to interferons deserve to be evaluated.

Genotypes and titers of hepatitis C virus for predicting response to interferon in patients with chronic hepatitis C

Interferon induces remission in about 50% of patients with chronic hepatitis C, but it is difficult to predict which patients will respond. Host and viral factors were evaluated for correlation with response to interferon in patients with chronic hepatitis C. Recombinant interferon alpha-2b with a total dose of 480-560 million units was given to 136 patients, of whom 74 (54%) responded. Genotypes of hepatitis C virus (HCV) in sera, I, II, III, IV, and V, were determined by polymerase chain reaction (PCR) with type-specific primers. In 72 patients, pretreatment levels of HCV RNA were titrated by PCR in serial tenfold dilutions of RNA extracted from serum. Response to interferon occurred in 34 (40%) of 85 patients infected with HCV of genotype II, less frequently than in 22 (85%) of 26 with genotype III (P < 0.001) or in 7 (70%) of 10 with genotype IV. Of 51 patients with genotype II HCV, 6 of 8 (75%) with HCV RNA titers < 10(6) responded, more frequently than 4 of 43 (9%) with titers > or = 10(6) (P < 0.001). Responders were younger than non-responders (45.7 +/- 11.7 vs. 50.3 +/- 9.6 yr) and had received transfusions less frequently (26/74 or 35% vs. 37/62 or 60%, P < 0.01). Response to interferon correlated inversely with the severity of liver histopathology. These results indicate that response to interferon is influenced by HCV genotypes and pretreatment levels of HCV RNA in serum.

Identification and genotyping of hepatitis C virus in injectable and oral drug users in New Zealand

BACKGROUND

Hepatitis C virus infections are known to be common in injectable drug users (IDU) both in New Zealand and overseas. Little is known of the hepatitis C genotype frequency in this population.

AIMS

To confirm the high incidence of hepatitis C virus infections in IDU and compare this with the frequency in oral drug users (ODU) as well as identify the pattern of hepatitis C genotypes present.

METHODS

Use was made of an experimental nucleocapsid assay as well as a conventional anti-HCV assay. HCV-RNA was identified using a polymerase chain reaction (PCR) technique and a variation of this method was used for HCV genotyping.

RESULTS

Seventy-four per cent of IDU were reactive for anti-HCV in both types of assay. PCR testing detected several more reactive samples. Dominant genotypes were Types I and V, but Type IV was not detected. Mixed infections were noted in some patients. There was a low frequency of anti-HCV in ODU.

CONCLUSIONS

Hepatitis C virus infections are a problem in IDU in New Zealand, and additional public health measures may be required. The distribution of genotypes of HCV-RNA are similar to those seen in other Western countries.

Induction of phosphatidylinositol turnover and EGR-1 mRNA expression by crosslinking of surface IgM and IgD in the human B cell line B104

We have previously shown that a human B lymphoma cell line, B104, expressed surface IgM (sIgM) and surface IgD (sIgD), and that crosslinking of sIgM and sIgD by anti-IgM antibody (Ab) and anti-IgD Ab, respectively, induced Ca2+ influx to almost the same degree, whereas only sIgM-crosslinking caused B104 cell death. Here, we investigated the accumulation of cyclic AMP (cAMP), the hydrolysis of inositol phosphates, protein kinase C (PKC) activity and the induction of Egr-1 and c-fos mRNA expression by sIgM- and sIgD-crosslinking to examine differences in the signals mediated through sIgM and sIgD in B104 cells. Both sIgM- and sIgD-crosslinking with antibodies induced elevation of cAMP levels, phosphatidylinositol turnover, PKC activation and expression of Egr-1 and c-fos mRNA, although sIgM-crosslinking was more effective than sIgD-crosslinking, presumably due to the higher expression of sIgM than of sIgD. Egr-1 mRNA expression induced by sIgM- and sIgD-crosslinking was inhibited by H7, erbstatin and genistein, but not by HA1004. Erbstatin and genistein inhibited the sIg-crosslinking-induced Egr-1 mRNA expression in a dose-dependent manner parallel to that observed in the inhibition of sIg-crosslinking-induced protein tyrosine phosphorylation. Phorbol myristate acetate induced Egr-1 mRNA expression but forskolin and dibutyryl cyclic AMP did not. These findings suggest that the Egr-1 mRNA activating signals through sIgM and sIgD are protein tyrosine kinase- and PKC-dependent, but protein kinase A-independent. Cyclosporin A (CsA) and FK506 rescued B104 cells from death induced by anti-IgM Ab, but did not affect the expression of Egr-1 and c-fos mRNA, showing that CsA and FK506 affect signal transducers differently from or downstream to these molecules. The difference in signals transduced through sIgM and sIgD in B104 cells is discussed.

Anti-Fas antibody induces different types of cell death in the human histiocytic cell line, U937, and the human B cell line, B104: the role of single-strand DNA breaks and poly (ADP-ribosyl)ation in cell death

We investigated the anti-Fas antibody-induced cell death in two different types of human cell lines, U937 and B104. IFN-gamma increased the surface expression of Fas antigen and susceptibility to anti-Fas Ab-induced cell death of B104 and U937 cells. Anti-Fas Ab-induced death of U937 and B104 cells required neither a Ca2+ influx nor macromolecular synthesis. U937 cells treated with anti-Fas Ab represented apoptosis with DNA fragmentation, whereas anti-Fas Ab-treated B104 cells did not. Single-strand DNA breaks, however, appeared in the B104 cells. Zinc ions prevented DNA fragmentation and the morphological features of apoptosis in anti-Fas Ab-treated U937 cells, but did not inhibit cell death. However, zinc ions, when used in combination with the poly(ADP-ribosyl)ation inhibitors, inhibited anti-Fas Ab-induced U937 cell death. The inhibitors by themselves did not inhibit anti-Fas Ab-induced U937 cell death, but did inhibit anti-Fas Ab-induced B104 cell death. A substantial decrease in NAD pools was observed in anti-Fas Ab-treated B104 and U937 cells in parallel with the increase of DNA strand breaks before cell death became apparent. These results suggest the involvement of single-strand DNA breaks and poly(ADP-ribosyl)ation in the mechanisms of anti-Fas Ab-induced U937 and B104 cell death.

Roles of eosinophils and catecholamines in pathophysiology of exercise-induced asthma

To study the roles of eosinophils and catecholamines in the pathophysiology of exercise-induced asthma (EIA), an exercise challenge test was performed in 22 asthmatic children, using a bicycle ergometer, and the changes in lung function, plasma norepinephrine (NE), epinephrine (E) and eosinophil cationic protein (ECP) levels with exercise were evaluated. Subjects were classified into three groups from the results of lung function test, respectively: EIA-negative group. EIA-positive groups with good recovery and poor recovery. Eosinophil counts before exercise in the EIA-positive groups were significantly higher than those in the EIA-negative group. The ECP levels rose with exercise in all groups. Five minutes after exercise, ECP values fell to the pre-exercise level in the EIA-negative group, but rose to higher levels in EIA-positive groups. Plasma E levels rose with exercise and showed 4-fold increase in the EIA-negative group, whereas only 1.5-fold increase of plasma E levels was observed in the EIA-positive group with poor recovery. From these findings, a possible contribution of sympathoadrenal hypofunction and a probable involvement of eosinophils in the pathophysiology of EIA have been suggested.

Genotype dependence of hepatitis C virus antibodies detectable by the first-generation enzyme-linked immunosorbent assay with C100-3 protein

Hepatitis C virus (HCV) samples in 155 sera, from patients with chronic non-A, non-B liver disease and blood donors, were grouped into four genotypes (I, II, III, and IV) by amplification of core-gene sequences by polymerase chain reaction with type-specific primers. HCV genotypes were compared with various HCV-associated antibodies detectable by the first-generation ELISA (ELISA-1) with C100-3 protein and a second-generation immunoblot assay with four recombinant HCV proteins. Antibodies to C100-3 protein and those to its subsequence (5-1-1) were detected in 13 (93%) and 12 (86%), respectively, of 14 sera with genotype I HCV; 56 (79%) and 58 (82%) of 71 sera with genotype II; 13 (34%) and 6 (16%) of 38 sera with genotype III; and 11 (34%) and 4 (13%) of 32 sera with genotype IV. Amino acid sequences of C100-3 of genotype I HCV are conserved by approximately 90% in genotype II, but only by approximately 75% in genotypes III and IV. The sensitivity of ELISA-1, therefore, would be influenced by heterogeneity in C100-3 sequences of different genotypes.

Characterization of an eosinophilic leukemia cell differentiation factor (ELDF) produced by a human T cell leukemia cell line, HIL-3

An adult T cell leukemia cell line, HIL-3, constitutively secretes a factor which induces the phenotypical and functional eosinophilic differentiation of a human eosinophilic leukemia cell line, EoL-1. Biochemical characteristics of the factor, termed eosinophilic leukemia cell differentiation factor (ELDF), were examined. ELDF was precipitated by 35 to 65% saturated ammonium sulfate from the culture supernatants of HIL-3 cells (HIL-3 sup). ELDF was eluted in a peak corresponding to a molecular weight of 30 to 40 kd by gel filtration. Isoelectric focusing in the Rotofor showed that ELDF had isoelectric points of 5 to 6. ELDF was trypsin-sensitive and stable to heat treatment at 65 degrees C for 30 minutes but labile at 80 degrees C or pH lower than 3. Half of the activity adhered to lentil-lectin but not to Con-A, indicating that a part of ELDF is glycoprotein with an N-linked carbohydrate moiety, which did not seem to be essential for ELDF activity. The biochemical characteristics of ELDF and blocking experiments using cytokine-specific neutralizing antibodies suggest that ELDF is different from gamma-interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5) and interleukin-2 (IL-2), which may exist in HIL-3 sup, and that ELDF may be a previously unrecognized leukemia differentiation factor.

Induction of phosphatidylinositol-linked Fc gamma receptor III expression on an eosinophilic cell line, EoL-1, by dibutyryl cyclic AMP and interferon-gamma

The expression of Fc gamma receptor III (Fc gamma RIII) on a human eosinophilic leukemia cell line, EoL-1, was examined and compared with its expression on normal blood eosinophils. Surface Fc gamma RIII expression on EoL-1 cells could be induced in vitro with a combination of dibutyryl cAMP (dbcAMP) and gamma-interferon (IFN-gamma), but not with IFN-gamma or dbcAMP alone. Pretreatment of EoL-1 cells with dbcAMP induced EoL-1 cells to express Fc gamma RIII when stimulated with IFN-gamma, but EoL-1 cells pretreated with IFN-gamma and then stimulated with dbcAMP failed to express Fc gamma RIII. Cyclic AMP was shown to play a role in the effect of dbcAMP. Both the treatment with phosphatidyl-inositol-specific phospholipase C (PI-PLC) and the restriction enzyme digestion of Fc gamma RIII cDNA showed that the Fc gamma RIII on EoL-1 cells was a phosphatidylinositol-linked form. On the other hand, freshly isolated blood eosinophils constitutively expressed few, if any, Fc gamma RIII, and IFN-gamma induced Fc gamma RIII expression on them in vitro. Dibutyryl cAMP did not induce Fc gamma RIII expression and even suppressed the IFN-gamma-induced Fc gamma RIII expression on normal eosinophils. The EoL-1 cell line appears to be a useful in vitro model for the expression and function of the phosphatidylinositol-linked form of Fc gamma RIII on eosinophils.

Cyclosporin A and FK506 block the negative signaling mediated by surface IgM cross-linking in normal human mature B cells

Cross-linking of surface IgM (sIgM) or sIgD by anti-IgM Ab or anti-IgD Ab, respectively, induced DNA synthesis in peripheral blood B cells (PBL-B). Cell division, determined by the increase in the number of M phase cells, was also induced when PBL-B were stimulated with anti-IgD Ab plus IL-4 or Staphylococcus aureus Cowan I (SAC), but far less by stimulation with anti-IgM Ab plus IL-4. Anti-IgM Ab did not suppress the DNA synthesis induced by SAC or anti-IgD Ab plus IL-4, but it did suppress the cell division induced by them. Thus, sIgM cross-linking generates both positive and negative signaling to B-cell proliferation. Cyclosporin A (CSA) and FK506 suppressed DNA synthesis and cell division at relatively high concentrations. On the other hand, CSA and FK506 at lower concentrations blocked the anti-IgM Ab-generated inhibition of cell division without affecting DNA synthesis. Low concentrations of CSA did not affect the cell division induced by anti-IgD Ab plus IL-4 but did increase the cell division induced by SAC or anti-IgM Ab plus IL-4, suggesting that stimulation with SAC, as well as with anti-IgM Ab plus IL-4, generates both positive and negative signals to cell division, whereas sIgD lacks the ability to transduce negative signaling.

[In vitro differentiation and Fc receptor expression of eosinophils]

Eosinophils express Fc gamma R II, together with some, if any, Fc gamma R I or Fc gamma R III. Fc epsilon R II is thought to be expressed only on the hypodense subpopulation of eosinophils. Dibutyryl cyclic AMP (dbcAMP) and gamma interferon (IFN-gamma) enhanced Fc gamma R II expression on both peripheral eosinophils and eosinophils derived in vitro by IL-5 from cord blood monoclear cells. IFN-gamma also enhanced Fc gamma R III expression on peripheral eosinophils only and not on IL-5-generated eosinophils. dbcAMP suppressed the IFN-gamma-induced Fc gamma R III expression on peripheral eosinophils. Other cytokines tested did not show any effect on Fc gamma R or Fc epsilon R II expression. These results suggest that expression of Fc gamma R subclasses and Fc epsilon R II on eosinophils is regulated differently and that cAMP and IFN-gamma play important roles in the regulation of Fc gamma R expression.

Trans-complementation among naturally occurring deletion mutants of hepatitis B virus and integrated viral DNA for the production of viral particles with mutant genomes in hepatoma cell lines

Cultured hepatoma cells (HepG2) were cotransfected with two different plasmids carrying a head-to-tail dimer of recombinant hepatitis B virus (HBV) DNA cloned from deletion mutants isolated from the circulation of persistently infected hosts. They were tested for the secretion of viral particles with mutant genome encapsidation. A recombinant plasmid defective in the S gene and one defective in both the C and P genes complemented in trans for the production of viral particles. Mutant genomes from either of the recombinants were encapsidated. Similarly, a recombinant defective in the C gene and another defective in the P gene trans-complemented for the production of viral particles containing mutant genomes. A hepatoma cell line with integrated HBV DNA sequences defective in the C and P genes (PLC/PRF/5) when transfected with a recombinant defective in the S gene produced viral particles with the HBV genome from the transfecting recombinants. These results confirm the expected trans-complementation among the S, C and P genes of HBV, when either episomal or integrated into chromosomes, for the maintenance of defective HBV mutants in persistently infected hosts.

Protein-losing gastroenteropathy with facial anomaly and growth retardation: a mild case of Hennekam syndrome

A 7-year-old boy with a peculiar face, protein-losing gastroenteropathy and growth retardation is reported. Although he has a face similar to those 5 cases reported previously by Hennekam et al. (Am J Med Genet 34:593-600, 1989) and Gabrielli et al. (Am J Med Genet 40:244-247, 1991), he is not mentally retarded nor does he have severe lymphedema. This patient seems to have a mild case of the Hennekam syndrome.

Allelic subtypic determinants of hepatitis B surface antigen (i and t) that are distinct from d/y or w/r

A monoclonal antibody (I-18) was raised against an enneapeptide representing amino acids 125 to 133 of the product of the S gene of hepatitis B virus DNA [S(125-133) segment] with a sequence of Thr-Ile-126-Pro-Ala-Gln-Gly-Thr-Ser-Met. Another monoclonal antibody (T-7) was raised against an S(125-133) segment in which Ile-126 was replaced by Thr-126. In a panel of 16 samples of hepatitis B surface antigen (HBsAg) with known S gene sequences, I-18 reacted with 5 with Ile-126. T-7 reacted with 10 HBsAg samples with Thr-126; it did not, however, react with the remaining one of subtype ayw with Thr-126 flanked by Met-125 and Thr-127. The two allelic subtypic determinants, specified by Ile-126 and Thr-126 and distinct from d/y or w/r, were named i and t after isoleucine and threonine, which regulate them. They were expressed in a mutually exclusive fashion in 216 (83%) of 260 HBsAg samples from asymptomatic carriers. They were not detected in 36 (14%) samples; the failure to detect an i or t determinant was particularly common in HBsAg samples of subtype ayw (26 [79%] of 33). A part of the S gene sequence was determined for eight HBsAg samples without a detectable i or t determinant. They had an Ile-126 or Thr-126 residue that was flanked by Thr-127, not the Pro-127 commonly possessed by HBsAg samples displaying an i or t determinant. Expression of the i/t allele, therefore, would require Pro-127. In eight (3%) of the samples, both i and t determinants were detected; the presence of i and t on the selfsame HBsAg particles was verified by sandwiching the particles between I-18 and T-7. A point mutation from thymine to cytosine at nucleotide 377 in the S gene, contributing different second letters to codon 126 (ATT for Ile and ACT for Thr), would have been responsible for the assembly of HBsAg particles with both i and t determinants by means of phenotypic mixing.

SDS-PAGE after micro-affinity adsorption for analysis of heterogeneous antigen polypeptides in individual sera

A method was developed for the analysis of heterogeneity in antigen polypeptides in individual sera. Polypeptides in sera were adsorbed by polystyrene beads coated with antibody in wells of a microplate. They were dissociated with a small volume of elutant, and transferred to slots on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Polypeptides separated on gel were then immunoblotted with antibodies labeled with horseradish peroxidase. The method was applied to analyze different populations of hepatitis B surface and e antigen polypeptides in sera from carriers of hepatitis B virus. Applicability to mass-scale and high sensitivity of the method would allow surveys of heterogeneous antigen polypeptides in serum for any biological significance.

Inhibitory effects of azelastine hydrochloride on Ca2+ influx, actin polymerization and release of eosinophil cationic protein of an eosinophilic leukaemia cell line EoL-1

The inhibitory effects of azelastine hydrochloride on PAF-induced and fMLP-induced Ca2+ influx, actin polymerization and calcium ionophore A23187-induced and aggregated IgG-induced release of eosinophil cationic protein (ECP) of an eosinophilic leukaemia cell line, EoL-1, were examined. EoL-1 cells cultured with 0.2 mM dibutyryladenosine-cyclic monophosphate for 48 hours showed an increase in intracellular free Ca2+ concentration ([Ca2+]i) and actin polymerization when stimulated by PAF and fMLP. Azelastine hydrochloride inhibited PAF-induced and fMLP-induced Ca2+ influx ([Ca2+]i) in a dose-dependent manner with an IC50 of 1 x 10(-8) M and 1 x 10(-7) M, respectively. It also inhibited PAF-induced and fMLP-induced actin polymerization in a dose-dependent manner up to 40% and 30%, respectively. EoL-1 cells were differentiated to contain ECP in their eosinophilic granules when cultured for 9 days with supernatants of a human adult T cell leukaemia cell line, HIL-3 (HIL-3 sup). Calcium ionophore A23187 and aggregated IgG induced the secretion of ECP by EoL-1 cells. Azelastine hydrochloride inhibited the secretion of ECP in a dose-dependent manner. These inhibitory effects were seen even at therapeutic concentrations of 10(-8) M to 10(-9) M. These results indicate that the therapeutic effects of azelastine hydrochloride as an anti-allergic agent may include inhibition of the accumulation of eosinophils into the locus of allergic inflammation and of the release of cytotoxic granules from eosinophils.

[Clinical evaluation of cefprozil in children]

Cefprozil (CFPZ, BMY-28100), a new oral cephalosporin, was evaluated for its efficacy and safety in 42 children with bacterial infections (Table 1), and the following results were obtained. 1. CFPZ was administered in 3 or 4 divided doses at daily dosages ranging from 15.3 to 60.0 mg/kg to 42 patients (19 cases of acute tonsillitis and/or laryngitis, pharyngitis, 13 cases of pneumonia, 2 cases each of suppurative cervical lymphadenitis and UTI, and 1 case each of scarlet fever, acute otitis media, suppurative parotitis, impetigo contagiosa, furuncle and acute enteritis) and the following clinical results were obtained: excellent; 24 cases, good; 14 cases, fair; 4 cases. The overall efficacy rate was 90.5% (Table 3). 2. MICs of CFPZ against 50 strains of isolated organisms are shown in Table 4. In 19 cases out of 28 cases examined, causative organisms were successfully eradicated and strain of Staphylococcus aureus was decreased in 1 case. 3. Diarrhea was observed in 2 cases (cases 8, 11). In case 8, the symptom disappeared spontaneously. Case 11 improved immediately after the administration of the drug was stopped. Among 39 children who went through laboratory tests, eosinophilia which seemed to be related to the administration of this drug was observed in 2 cases (cases 29, 38). Slight elevations of S-GOT and S-GPT were found in 1 case (case 22) (Table 7). 4. These data suggest that CFPZ is a safe and useful new antibiotic in the treatment of children with susceptible bacterial infections.

Regulation of the expression of leukocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) on a human eosinophilic leukemia cell line EoL-3

The effects of several cytokines and phorbol myristate acetate (PMA) on LFA-1 and ICAM-1 expression on a human eosinophilic leukemia cell line, EoL-3, were investigated and compared with those of a human monocytic leukemia cell line, U937. EoL-3 cells expressed large amounts of LFA-1 and small amounts of ICAM-1, and their expression was regulated similarly in EoL-3 cells and U937 cells. Interferon-gamma (IFN-gamma) enhanced ICAM-1 expression but not LFA-1 expression, and PMA augmented both LFA-1 and ICAM-1 expression. IFN-gamma and PMA showed an additive effect on ICAM-1 expression. These results collectively suggest that expression of LFA-1 and ICAM-1 is regulated differently and that IFN-gamma and PMA regulate the expression through different mechanisms. PMA but not IFN-gamma induced homotypic adhesion of EoL-3 and U937 cells, suggesting that PMA but not IFN-gamma activated the adhesive function of these cells. Staurosporin, an inhibitor of protein kinases (PKs), partly suppressed IFN-gamma- and PMA-augmented expression of ICAM-1 on EoL-3 and U937 cells, but did not affect PMA-augmented LFA-1 expression, suggesting that staurosporin-sensitive PKs are involved in IFN-gamma- and PMA-augmented ICAM-1 expression but not in PMA-augmented LFA-1 expression. The role of protein kinase C (PK-C) in these mechanisms was not revealed because a PK-C inhibitor, H-7, did not show any definitive effect on IFN-gamma- and PMA-induced expression of LFA-1 and ICAM-1. Moreover, cyclic AMP (cAMP)- and cGMP-dependent pathways were not shown to be involved in the augmentation of the expression of these molecules.

Correlation between anti-HBc titers and HBV DNA in blood units without detectable HBsAg

Hepatitis B virus (HBV) DNA was tested for in 294 blood units which had antibody against hepatitis B core antigen (anti-HBc) as the isolated serological marker of HBV infection. After amplification by polymerase chain reaction, HBV DNA was detected in 12 (6.9%) of 175 units that were positive for anti-HBc with hemagglutination inhibition titers greater than or equal to 2(6), significantly more often than in none of 119 units with titers less than or equal to 2(5) (p less than 0.01). These results indicate that the exclusion of blood units with isolated high-titer anti-HBc would be effective for further decreasing the risk of posttransfusion hepatitis B.

Hepatitis B surface antigen particles of subtypes adw and adr, and compound subtype (adwr) in symptom-free carriers in Japan

Of sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped as adw (22.4%) and 1,443 as adr (76.8%); only 15 (0.8%) contained HBsAg of subtype ayw or ayr. Sera with HBsAg/adr had higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 +/- 2.4 vs. 9.7 +/- 2.4, p less than 0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%, p less than 0.001). Carriers of HBsAg/adr progressively predominated over those of HBsAg/adw with increasing age. Of sera from 1,863 carriers of HBsAg/adw or HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in the w/r allele. The presence of w and r determinants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype (adwr) were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%], p less than 0.001). Sera with HBsAg/adwr particles had HBsAg titres higher than those without them (12.4 +/- 1.9 vs. 9.7 +/- 2.3, p less than 0.001). HBsAg/adwr particles arise from phenotypic mixing of the S-gene product of wild-type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtype adr have a higher replicative activity than those of adw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus.

Tyrosine phosphorylation of IgM- and IgD-associated molecules of a human B lymphoma cell line B104

We investigated tyrosine phosphorylation and structural properties of the IgM-associated molecules in comparison with IgD-associated molecules in a recently established human surface IgM+, IgD+ B lymphoma cell line, B104, the growth of which was irreversibly inhibited by anti-IgM mAbs but not by anti-IgD mAbs. Tyrosine kinase activity and tyrosine phosphorylated proteins were detected in anti-IgM and anti-IgD immunoprecipitates from digitonin lysates of B104 cells with the use of an in vitro kinase assay followed by a re-immunoprecipitation experiment with anti-phosphotyrosine mAbs. Tyrosine phosphorylated proteins of 74, 58-44, 41, and 39 kDa were detected in anti-IgM immunoprecipitates, whereas tyrosine phosphorylated proteins of 74, 58-44, and 39 kDa, but not 41 kDa, were detected in anti-IgD immunoprecipitates. Crosslinking of surface IgM and surface IgD stimulated rapid tyrosine phosphorylation of different sets of proteins which included tyrosine-phosphorylated proteins of the same or similar molecular weights as those detected in the anti-IgM and anti-IgD immunoprecipitates respectively. After deglycosylation by N-glycosidase, both the IgM- and IgD-associated phosphoproteins (pp58-pp39) gave rise to the same three bands of 29, 27, and 26 kDa. Proteolytic peptide mapping of these three deglycosylated proteins showed that the primary structures of the IgM- and IgD-associated molecules are identical, suggesting that the IgM- and IgD-associated phosphoproteins (pp58-pp39) are the products of the same or closely related genes. One of the products, pp41, may be associated with IgM, but not with IgD, although the same gene product may be associated with IgD in a different glycosylation pattern.

EoL-1, a human eosinophilic cell line

EoL-1 cells, a recently established human eosinophilic leukemia cell line, have cytological features of myeloblasts under normal culture conditions, and differentiate not only phenotypically but also functionally into eosinophils by a number of stimuli. EoL-1 cells are particularly useful for analyzing leukemic cell differentiation and the properties of malignant eosinophils. EoL-1 cells are also a useful in vitro model for studying human eosinophil functions and their regulation.

Regulation of cell division of mature B cells by ionomycin and phorbol ester

The growth of a human B lymphoma cell line B104, an experimental model for mature B cells, was inhibited by ionomycin but not 12-O-tetradecanoylphorbol-13-acetate (TPA). Ionomycin inhibited B104 cells from entering into the M phase of the cell cycle without affecting DNA synthesis. The inhibition of cell division of B104 cells by ionomycin occurred within 24 h after stimulation. Because such a mode of action resembles that of anti-IgM antibodies, signals transduced by Ca2+ may be responsible for the inhibition of cell division of B104 cells by anti-IgM antibodies. Indeed, EGTA suppressed the inhibition of cell division of B104 cells caused not only by ionomycin, but also by anti-IgM antibody. Although TPA itself did not have any ability to promote the growth of B104 cells, it could cancel the inhibition of cell division of B104 cells by ionomycin and increase the proportion of B104 cells entering into the M phase of the cell cycle. Staphylococcus aureus Cowan I causes the greatest proliferation of normal human peripheral blood B cells during the period from 48 to 72 h after stimulation. When ionomycin was added to S. aureus Cowan I-stimulated peripheral blood B cells at 48 h of culture, it inhibited cell division during this period without affecting DNA synthesis. In the presence of TPA, this activity of ionomycin was suppressed, and the proportion of M-phase cells increased. These results suggest that cell division of mature B cells is regulated by the signals mediated by Ca2+ and protein kinase C in a mode quite different from that of regulation of DNA synthesis.

Regulation of cell division of mature B cells by ionomycin and phorbol ester

The growth of a human B lymphoma cell line B104, an experimental model for mature B cells, was inhibited by ionomycin but not 12-O-tetradecanoylphorbol-13-acetate (TPA). Ionomycin inhibited B104 cells from entering into the M phase of the cell cycle without affecting DNA synthesis. The inhibition of cell division of B104 cells by ionomycin occurred within 24 h after stimulation. Because such a mode of action resembles that of anti-IgM antibodies, signals transduced by Ca2+ may be responsible for the inhibition of cell division of B104 cells by anti-IgM antibodies. Indeed, EGTA suppressed the inhibition of cell division of B104 cells caused not only by ionomycin, but also by anti-IgM antibody. Although TPA itself did not have any ability to promote the growth of B104 cells, it could cancel the inhibition of cell division of B104 cells by ionomycin and increase the proportion of B104 cells entering into the M phase of the cell cycle. Staphylococcus aureus Cowan I causes the greatest proliferation of normal human peripheral blood B cells during the period from 48 to 72 h after stimulation. When ionomycin was added to S. aureus Cowan I-stimulated peripheral blood B cells at 48 h of culture, it inhibited cell division during this period without affecting DNA synthesis. In the presence of TPA, this activity of ionomycin was suppressed, and the proportion of M-phase cells increased. These results suggest that cell division of mature B cells is regulated by the signals mediated by Ca2+ and protein kinase C in a mode quite different from that of regulation of DNA synthesis.

Tyrosine phosphorylation and its possible role in superoxide production by human neutrophils stimulated with FMLP and IgG

Superoxide production by human neutrophils stimulated with FMLP and soluble aggregated human IgG were inhibited in a dose dependent manner by two kinds of tyrosine kinase inhibitors, erbstatin and genistein. Superoxide production stimulated with surface bound IgG, however, was scarcely inhibited by either inhibitor. Protein tyrosine phosphorylation studies with immunoblotting revealed specific tyrosine phosphorylation of a 40 Kd protein by soluble aggregated and surface bound IgG, and that of a 39 Kd protein, as well as the 40 Kd protein, by FMLP. These were all inhibited by the tyrosine kinase inhibitors. These data suggest that superoxide production induced by FMLP and soluble aggregated IgG are, at least in part, tyrosine kinase dependent, but the tyrosine kinases and/or substrates of tyrosine kinases involved may be different. In addition, tyrosine kinase independent pathways are also suggested to be involved in superoxide production by stimulation with surface bound IgG.

Anti-IgM antibody-induced cell death in a human B lymphoma cell line, B104, represents a novel programmed cell death

We investigated the mechanisms of anti-IgM antibody-induced cell death in a recently established human surface IgM+ IgD+ B lymphoma cell line, B104, the growth of which is irreversibly inhibited by anti-IgM antibody but not by anti-IgD antibody, and compared it with the cell death of T cells via TCR/CD3 complex and with the cell death of a murine anti-IgM antibody-sensitive B lymphoma cell line, WEHI-231. The rapid time course of B104 cell death and its requirements for de novo macromolecular synthesis and Ca2+ influx suggest that anti-IgM antibody-induced B104 cell death is an active Ca(2+)-dependent programmed cell death. Moreover, cyclosporin A rescued B104 cells from this lethal signal, via surface IgM, suggesting that the intracellular mechanisms involved are quite similar to those of T cell death. DNA fragmentation, which has been reported in TCR/CD3 complex-mediated T cell death, apoptosis, was not involved in the B104 cell death process, but the possible involvement of DNA single-strand breaks was suggested. Observations under light microscopy and transmission electron microscopy indicated that the morphologic features of dying B104 cells resembled necrosis rather than apoptosis. B104 cell death was shown to be quite distinct from that of WEHI-231 in cell death kinetics, the mode of cell death, and the response to cyclosporin A. These data collectively indicate that the death of B104 cells resulting from surface IgM cross-linking represents a hitherto undefined mode of programmed cell death.

Anti-IgM antibody-induced cell death in a human B lymphoma cell line, B104, represents a novel programmed cell death

We investigated the mechanisms of anti-IgM antibody-induced cell death in a recently established human surface IgM+ IgD+ B lymphoma cell line, B104, the growth of which is irreversibly inhibited by anti-IgM antibody but not by anti-IgD antibody, and compared it with the cell death of T cells via TCR/CD3 complex and with the cell death of a murine anti-IgM antibody-sensitive B lymphoma cell line, WEHI-231. The rapid time course of B104 cell death and its requirements for de novo macromolecular synthesis and Ca2+ influx suggest that anti-IgM antibody-induced B104 cell death is an active Ca(2+)-dependent programmed cell death. Moreover, cyclosporin A rescued B104 cells from this lethal signal, via surface IgM, suggesting that the intracellular mechanisms involved are quite similar to those of T cell death. DNA fragmentation, which has been reported in TCR/CD3 complex-mediated T cell death, apoptosis, was not involved in the B104 cell death process, but the possible involvement of DNA single-strand breaks was suggested. Observations under light microscopy and transmission electron microscopy indicated that the morphologic features of dying B104 cells resembled necrosis rather than apoptosis. B104 cell death was shown to be quite distinct from that of WEHI-231 in cell death kinetics, the mode of cell death, and the response to cyclosporin A. These data collectively indicate that the death of B104 cells resulting from surface IgM cross-linking represents a hitherto undefined mode of programmed cell death.

Anti-IgM but not anti-IgD antibodies inhibit cell division of normal human mature B cells

Insolubilized anti-IgD antibody markedly increased DNA synthesis in and cell division of normal peripheral blood B cells (PBL-B) when used in combination with IL-4. Anti-IgM antibodies also induced DNA synthesis of PBL-B, but their ability to induce cell division was less than that of anti-IgD antibodies even when used in combination with IL-4. Moreover, anti-IgM antibodies inhibited cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4 without affecting DNA synthesis. Anti-IgM antibodies also inhibited Staphylococcus aureus Cowan I-induced cell division of PBL-B without affecting DNA synthesis. These results indicate that cross-linkage of surface IgM (sIgM) in mature B cells generates negative signals to inhibit cell division of mature B cells. Because anti-IgD antibodies did not inhibit cell division at all, the role of sIgD in the regulation of cell division of mature B cells may be quite different from that of sIgM. IFN-alpha/beta promoted cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4. They also counteracted the inhibitory effect of anti-IgM antibody on cell division of PBL-B.

Anti-IgM but not anti-IgD antibodies inhibit cell division of normal human mature B cells

Insolubilized anti-IgD antibody markedly increased DNA synthesis in and cell division of normal peripheral blood B cells (PBL-B) when used in combination with IL-4. Anti-IgM antibodies also induced DNA synthesis of PBL-B, but their ability to induce cell division was less than that of anti-IgD antibodies even when used in combination with IL-4. Moreover, anti-IgM antibodies inhibited cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4 without affecting DNA synthesis. Anti-IgM antibodies also inhibited Staphylococcus aureus Cowan I-induced cell division of PBL-B without affecting DNA synthesis. These results indicate that cross-linkage of surface IgM (sIgM) in mature B cells generates negative signals to inhibit cell division of mature B cells. Because anti-IgD antibodies did not inhibit cell division at all, the role of sIgD in the regulation of cell division of mature B cells may be quite different from that of sIgM. IFN-alpha/beta promoted cell division of PBL-B stimulated with insolubilized anti-IgD antibody plus IL-4. They also counteracted the inhibitory effect of anti-IgM antibody on cell division of PBL-B.

Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus

Hepatitis B e Ag (HBeAg) was isolated from pooled sera of carriers, without abnormalities in liver function, by affinity column chromatography with mAb against HBeAg. HBeAg polypeptide with an estimated molecular size of 20,000 Da (p20e) was detected, in addition to regular HBeAg polypeptides (p17e/p18e). p20e, as well as p17e/p18e, did not bind with mAb against the carboxyl-terminal domain of the C-gene product. p20e disclosed an N-terminal sequence of MQLFHLXLII- (X unknown), whereas p17e had that of SKLXLGXLXGMDIDPXKEFG- (X's unknown). By comparing them with the amino acid sequence encoded by the precore region and C gene of hepatitis B virus DNA, p20e was deduced to possess amino acids 1 to 19 of the precore-region product at the N-terminus, which contains signal sequence and usually removed before the secretion of HBeAg. p17e had amino acids 20 to 29 of the precore-region product that continued to the C-gene product. Inasmuch as p20e was invariably detected in HBeAg preparations from carriers without evidence for liver disease, it would not have been released into the circulation from destructed hepatocytes. HBeAg polypeptide bearing an uncleaved signal sequence would help in further understanding the mechanism of HBeAg secretion.

Nucleotide sequence of the genomic RNA of hepatitis C virus isolated from a human carrier: comparison with reported isolates for conserved and divergent regions

The complete nucleotide sequence of a hepatitis C virus derived from plasma of a human carrier in Japan was determined. The cDNA of the isolate (HC-J6) contained 9481 nucleotides and an additional T stretch of 30 to 108 nucleotides at the 3' end, and had one large open reading frame coding for a polyprotein of 3033 amino acids. It differed by 31.8 to 32.1% in the nucleotide sequence and by 27.4 to 27.7% in the amino acid sequence from an American isolate and two Japanese isolates previously reported. Among these four isolates, the 5' non-coding region of 329 to 341 nucleotides was well conserved (greater than 93% identity), whereas the 3' non-coding region of 39 to 45 nucleotides (T stretches not included) was more variable (greater than 30% identity). An excellent degree of conservation of the 5' non-coding region would reflect its pivotal role in replication, and primers deduced from this region could be applied for the sensitive and specific detection of viral RNA by polymerase chain reaction. Due to a high degree of similarity in the amino acid sequence of the putative core protein (greater than 90%), antigen probes deduced from it would be suitable for the serological diagnosis of HCV infection. Low sequence similarity in the putative envelope protein (greater than 53% identity), however, would have to be taken into account in considering the immunoprophylaxis of HCV infection.

Phosphorylation in the carboxyl-terminal domain of the capsid protein of hepatitis B virus: evaluation with a monoclonal antibody

The capsid protein of hepatitis B virus (p21c) is made of 183 amino acids coded for by the C gene. By using p21c isolated from Dane particles (hepatitis B virus) as an immunogen, a monoclonal antibody (no. 2212) which recognized an epitope dependent on the phosphorylation of p21c was raised. The binding of no. 2212 antibody to authentic p21c was completely inhibited by a synthetic undecapeptide with a sequence of RRRSQSPRRRR, representing amino acids 165 to 175 of p21c, only when the peptide was phosphorylated. Either or both of Ser-168 and Ser-170 were phosphorylated in p21c in vivo, therefore, and contributed to the manifestation of the epitope. No. 2212 antibody bound to p21c from core particles derived from Dane particles or hepatocellular carcinoma tissues (PLC/342) propagated in nude mice but did not bind to p21c from core particles expressed in Escherichia coli or yeast cells, indicating different states of phosphorylation in them. Nonphosphorylated p21c showed a higher affinity for the viral DNA than did phosphorylated p21c. Since the serum from an asymptomatic carrier, with a high titer for antibody to hepatitis B core antigen, specifically bound to phosphorylated undecapeptide (amino acids 165 to 175), the epitope would stimulate humoral antibody responses in the human host.

Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus

Hepatitis B e Ag (HBeAg) was isolated from pooled sera of carriers, without abnormalities in liver function, by affinity column chromatography with mAb against HBeAg. HBeAg polypeptide with an estimated molecular size of 20,000 Da (p20e) was detected, in addition to regular HBeAg polypeptides (p17e/p18e). p20e, as well as p17e/p18e, did not bind with mAb against the carboxyl-terminal domain of the C-gene product. p20e disclosed an N-terminal sequence of MQLFHLXLII- (X unknown), whereas p17e had that of SKLXLGXLXGMDIDPXKEFG- (X's unknown). By comparing them with the amino acid sequence encoded by the precore region and C gene of hepatitis B virus DNA, p20e was deduced to possess amino acids 1 to 19 of the precore-region product at the N-terminus, which contains signal sequence and usually removed before the secretion of HBeAg. p17e had amino acids 20 to 29 of the precore-region product that continued to the C-gene product. Inasmuch as p20e was invariably detected in HBeAg preparations from carriers without evidence for liver disease, it would not have been released into the circulation from destructed hepatocytes. HBeAg polypeptide bearing an uncleaved signal sequence would help in further understanding the mechanism of HBeAg secretion.

Dibutyryl cyclic AMP induces formyl peptide receptor expression and chemotactic responses in a human eosinophilic cell line, EoL-1

We investigated actin polymerization and the increase of cytosolic free calcium concentration ([Ca2+]i) in a human eosinophilic leukemia cell line, EoL-1, in response to stimulation with chemotactic factors; we also investigated the effect of dibutyryl cyclic AMP (dbcAMP) on the responses. EoL-1 cells under normal culture conditions did not show either actin polymerization or an increase in [Ca2+]i when stimulated with formyl-methionyl-leucyl-phenylalanine (fMLP). Expression of formyl peptide receptors was not detectable on untreated EoL-1 cells, either. Dibutyryl cAMP induced the expression of formyl peptide receptors and the responsiveness to fMLP. The responsiveness of EoL-1 cells to the complement fragment C5a and platelet-activating factor (PAF) was also induced or enhanced by dbcAMP. The growth of EoL-1 cells was decreased and the proportion of cells in the G0/G1 phase of the cell cycle was increased by the treatment of EoL-1 cells with dbcAMP. The proportion of eosinophilic granule-containing cells and the content of eosinophil cationic protein (ECP) in EoL-1 cells was also increased when they were stimulated with dbcAMP for a longer period. The responsiveness of EoL-1 cells to fMLP, C5a, and PAF was shown to be regulated independently. EoL-1 cells and dbcAMP seem to be useful for examining chemotactic receptor expression and its signal transduction mechanisms.

Seroepidemiology of hepatitis C virus infection in the Philippines: a preliminary study and comparison with hepatitis B virus infection among blood donors, medical personnel, and patient groups in Davao, Philippines

To determine the seroprevalence of hepatitis C virus in the Philippines and compare it with the seroprevalence of hepatitis B virus infection, HBV and HCV markers in 594 serum samples collected from 392 blood donors, 123 medical and paramedical personnel, and 80 patients (45 liver diseases: 25 acute hepatitis, 9 liver cirrhosis, and 11 hepatocellular carcinoma; 28 hepatitis B carriers, and 7 chronic renal failure patients undergoing dialysis) in Davao, Mindanao Island, Philippines, were examined. HBsAg was determined by RPHA, anti-HBc by HI, anti-HBs by PHA, and HBsAg subtypes, HBeAg, and anti-HBe by EIA. HCV markers determined were anti-HCV (anti-C100-3) by ELISA (Ortho Diagnostic Systems), and anti-HCV core (anti-CP9 and/or anti-CP10) also by ELISA. Results showed that 9 (2.2%) blood donors were anti HCV positive; 69 (15.4%) were anti-HCV core positive Nine (2.2%) were HBsAg carriers; 240 (61.3%) were anti-HBs and/or anti-HBc positive (HBsAg carriers excluded from this group). Two of 123 medical and paramedical staff (1.6%) were anti-HCV positive; 11 (8.1%) were anti-HCV core positive; Eight (6.5%) were HBsAg carriers and 81 (65.8%) anti-HBs and/or anti-HBc positive. Five of 11 (45.4%) hepatocellular carcinoma patients were HBsAg carriers; 2 were anti-HCV core positive. Two of 9 liver cirrhosis patients were anti-HCV positive (1 to anti-HCV and the other to anti-HCV core).(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation of a human eosinophilic leukemia cell line (EoL-1) by a human T-cell leukemia cell line (HIL-3)-derived factor

Differentiation of a human eosinophilic leukemia cell line, EoL-1, induced by the culture supernatant of a human ATL cell line, HIL-3 (HIL-3 sup) was compared with differentiation induced by defined cytokines. HIL-3 sup induced EoL-1 cells to express eosinophilic granules and segmented nuclei after 6 to 9 days of incubation. HIL-3 sup also induced the expression of Fc epsilon receptor II (Fc epsilon RII/CD23) and an eosinophil differentiation antigen EO-1 mainly on eosinophilic granule (+) cells. Furthermore, HIL-3 sup induced EoL-1 cells to respond to an eosinophil chemotactic factor, platelet activating factor. HIL-3 cells express messenger RNA (mRNA) of interleukin-5 (IL-5), macrophage colony-stimulating factor (M-CSF), and IL-3 but not granulocyte CSF (G-CSF). Granulocyte-macrophage CSF (GM-CSF) and tumor necrosis factor-alpha (TNF-alpha) were detected in the HIL-3 sup. Recombinant IL-2 (rIL-2), rIL-3, rIL-4, rIL-5, rM-CSF, and rGM-CSF did not induce eosinophilic granules. rG-CSF induced a few eosinophilic granule (+) cells, and TNF-alpha, which did not induce eosinophilic granules by itself, enhanced the ability of G-CSF to induce them. However, G-CSF and TNF-alpha did not induce the expression of Fc epsilon RII and EO-1 antigen. Moreover, anti-G-CSF, anti-TNF-alpha, anti-GM-CSF, anti-IL-3, and anti-IL-5 antibodies did not suppress the effect of HIL-3 sup on the differentiation of EoL-1 cells. All the data suggest that HIL-3 sup contains an unidentified factor that induces differentiation of EoL-1 cells, and that EoL-1 cells and HIL-3 sup provide an important model for the examination of differentiation mechanisms and functions of eosinophils.

[Clinical evaluation of cefpirome in children]

Cefpirome (CPR, HR 810) was clinically evaluated for its efficacy and safety in 11 patients with ages from 4 months to 11 years with bacterial infection. The results obtained are summarized as follows. 1. CPR was administered to 6 patients with bronchopneumonia, a patient with pneumonia, a patient with tonsillitis, 2 patients with acute pharyngitis and a patient with suppurative parotitis at daily dosage levels ranging 55.5-91.7 mg/kg, divided into 3 using intravenous bolus injection or 30 minutes drip infusion. Clinical responses of the 11 patients were as follows: excellent; 8 patients, good; 2 patients, poor; 1 patient, hence the efficacy rate was 90.9%. 2. Neither clinical adverse reaction nor abnormal laboratory test value was observed except slight elevation of GOT and GPT in a patient and leukopenia in another. 3. MICs of CPR against 18 beta-lactamase producing strains isolated from patients were as follows. MIC against a strain of Staphylococcus aureus was 1.56 micrograms/ml, MICs against 3 strains of Klebsiella pneumoniae were less than 0.025 microgram/ml, those against 3 out of 5 strains of Enterobacter cloacae were less than 0.025 microgram/ml and those against the remaining 2 strains were 0.05 and 0.20 micrograms/ml. MICs against 2 out of 3 strains Acinetobacter lwoffi were 1.56 micrograms/ml, and that of the remaining 1 strain was 0.39 microgram/ml. MICs against 2 strains of Pseudomonas cepacia were 1.56 micrograms/ml. MICs against a strain of Pseudomonas putida and a strain of Citrobacter diversus were 0.78 and less than 0.025 microgram/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)