Toshio Miyawaki

Expression of both types of human interleukin-8 receptors on mature neutrophils, monocytes, and natural killer cells.

cDNA cloning revealed the presence of two related but distinct types of human interleukin‐8 (IL‐8) receptors, type I (type A) and type II (type B). By immunizing rabbits with glutathione‐S‐transferase fused with the NH2‐terminal domain of each type of IL‐8 receptor, we prepared polyclonal antibodies that specifically recognized the NH2‐terminal domain of each type of IL‐8 receptor. Immunofluorescence analysis of human peripheral blood leukocytes demonstrated that mature granulocytes except eosinophils express both types of IL‐8 receptors. A majority of monocytes and CD16+ natural killer (NK) cells in peripheral blood were stained with both antibodies, whereas CD3+ T or CD20+ B lymphocytes in peripheral blood or CD34+ cells in cord blood were not stained with either antibody. These results suggest that both types of human IL‐8 receptors were coordinately and selectively expressed in mature granulocytes, monocytes, and CD16+ NK cells. J. Leukoc. Biol. 57: 180–187; 1995.

Maturation of B-cell differentiation ability and T-cell regulatory function in infancy and childhood.

The immunologic ontogeny of the child is a biological growth process. The development of antibody response requires the generation of antigen-responsive B lymphocytes and, for response to most antigens, the functional maturation of T lymphocytes and macrophages. There are many imbalances of T cells and their interactions with other cells in the immune system in early human ontogeny. Pokeweed mitogen (PWM) has been the most studied human B cell mitogen and its use has yielded valuable information in human B cell ontogeny. However, PWM is a T cell-dependent B cell mitogen and. cord blood T lymphocytes, unlike adult T cells, are triggered by PWM to become activated suppressor T cells that prevent nonspecifically the differentiation of B cells into immunoglobulin (Ig)-producing cells (Oldstone et al. 1977, Hayward & Lawton 1977). Such neonatal suppressor activity is seen in other situations where cellular interactions take place, as demonstrated by the inhibitory effect of T cells from newborn babies, exerted on the proliferative response of normal lymphocytes and adult B cell differentiation (Olding & Oldstone 1976, Hayward & Lydyard 1978).

Expression of CD45R0 (UCHL1) by CD4^+ and CD8^+ T cells as a sign of in vivo activation in infectious mononucleosis

CD4SR0 (UCHL1), a member of leucocyte common antigen family, is expressed largely on previously activated or memory T cells. We examined CD45R0 expression of T cell subpopulations in patients with Epstein‐Barr virus (EBV) induced infectious mononucleosis (IMN) as a sign of in vivo activation. Consistent with the notion that activated CD8+ T cells expand in acute IMN, the majority of CD8+ T cells in patients with acute IMN expressed CD45R0 to the similar extent to HLA‐DR expression. Most CD4+ T cells in these patients also demonstrated marked expression of CD45R0 as well as HLA‐DR antigens, compared with age‐matched controls. Expression of CD45R0 by CD4+ T cells in patients with acute IMN was more notable than their HLA‐DR expression. While predominant CD8+ T cells resulted in decreased percentages of CD4+ T cells, CD4+ T cells expressing CD4SR0 were shown to be significantly elevated in absolute number. The results suggest that both CD4+ and CD8+ T cells may be activated by stimulation with EBV infection. The appearance of two T cell subpopulations expressing CD4SR0 in acute IMN implies their immunoregulatory roles in the control of EBV‐infected cells.

Effector and precursor phenotypes of lymphokine-activated killer cells in mice with severe combined immunodeficiency (scid) and athymic (nude) mice

The lineage of lymphokine-activated killer (LAK) cells is poorly understood. To examine the relationship between LAK and natural killer (NK) cells we utilized two congenitally immunodeficient mice, namely severe combined immunodeficient (scid) and athymic (nude) mice that lack T cells but have normal NK cells. LAK activity was evaluated by the ability to lyze NK-resistant P815 cells. When cultured with human recombinant interleukin 2, splenocytes of scid and nude mice could generate LAK activity at levels comparable to or more than those of normal C.B-17 mice. LAK effector cells in these immunodeficient mice as well as normal mice had the phenotype resembling that of NK cells with asialo-GM1 (aGM1) expression. In vivo treatment with anti-aGM1 antiserum completely abolished the induction of LAK activity from splenocytes of normal mice. In contrast, LAK activity in splenocytes of scid and nude mice was still demonstrable even after this treatment, indicating that most LAK precursors in both mice were cells without aGM1 antigen. The aGM1- progenitors for LAK activity, probably in common with NK progenitors, appeared to be more expanded in scid and nude mice than in normal mice. The use of such congenitally immunodeficient mice should be helpful in studying the differentiation step of LAK as well as NK cells from their precursors.

Increased levels of urinary interleukin-6 in Kawasaki disease

Kawasaki disease (KD) often presents with abnormal urinary findings, such as aseptic pyuria, mild proteinuria and microscopic haematuria. In this study, we measured urinary interleukin-6 (IL-6) by a sensitive sandwich ELISA assay using mouse monoclonal antibodies against recombinant IL-6 to elucidate the role of IL-6 in the pathogenesis of renal lesions in KD. Serum IL-6 levels were increased in acute KD as well as in febrile controls. Importantly, urinary IL-6 levels were consistently elevated in patients with acute KD, but much lower in febrile controls. Urinary IL-6 levels returned steadily to normal during the convalescent phase. In addition to IL-6, urinary levels ofN-acetyl-β-d-glucosaminidase (NAG) and β2-microglobulin (β2-mg) were also elevated during the acute phase of this disease. Eosinophils and macrophages were identifiable in urinary sediments from these patients. The increased levels of urinary IL-6 in combination with increased NAG and β2-mg seemed to suggest the presence of certain renal parenchymal lesions with cellular infiltration during the acute phase of the disease. IL-6 may serve as clinically useful parameter for the detection and monitoring of the renal involvement in KD.

G-CSF enhances the immunoglobulin generation rather than the proliferation of human B lymphocytes

Abstract: The effect of granulocyte‐colony stimulating factor (G‐CSF) on human B‐cell function was studied in in vitro cultures. G‐CSF alone had no effect on the proliferative response of resting B cells, but it slightly enhanced the proliferative response of these cells in the presence of polyclonal B‐cell mitogen, Staphylococcus aureus Cowan strain I (SAC) at concentrations of 0.2 to 25 μg/ml (1.5‐fold increase in the DNA synthesis). In contrast, immunoglobulin (Ig) secretion of activated B cells was increased approximately three‐fold to four‐fold by adding G‐CSF to the cultures. The neutralization of G‐CSF bioactivity with anti‐G‐CSF antibody abrogated this effect. Though cytoplasmic Ig‐positive cells or plasma cell marker‐positive cells did not change, the expression of IgM mRNA in antibody‐producing B cells increased in the presence of G‐CSF in the cultures. Interestingly, human B lymphocytes are shown to express the binding to biotin‐conjugated G‐CSF preparation, but not to biotin‐conjugated GM‐CSF preparation when examined by flow cytometry. These data suggest that G‐CSF may influence B‐cell function in special circumstances.

T-cell-dependent production of IgG by human cord blood B cells in reconstituted SCID mice

Reconstitution of severe combined immunodeficient (SCID) mice with human lymphocytes has recently allowed the elucidation of abnormalities of immune responses in various immunological disorders. In the present study, mononuclear cells (MNC) from neonatal cord blood and adult peripheral blood were intraperitoneally injected into SCID mice to examine induction of human Ig in respective mice recipients. Human IgG was consistently detected in the serum of SCID transferred with adult MNC, but only a few SCID recipients of cord blood MNC showed detectable but low levels of IgG in the serum. The combination experiments of isolated B and T cells disclosed that some interactions between B and T cells might be necessary for IgG production in transferred SCID mice. Notably, transfer of cord blood B cells with adult but not cord blood T cells resulted in efficient induction of IgG, associated with a change in subclass distribution. The results suggest that inability of neonatal B cells to produce IgG can be overcome by transfer with adult mature T cells into SCID mice.

Absence of CD69 expression on peripheral eosinophils in episodic angioedema and eosinophilia.

A 45‐year‐old woman with episodic angioedema and eosinophilia is presented. CD69, which is one of the surface antigens of activated eosinophils, was not expressed on the peripheral eosinophils in this patient, in contrast to hypereosinophilic syndrome. This suggests that CD69, which is not dependent on eosinophil density, may be another useful activation marker of eosinophils to distinguish episodic angioedema and eosinophilia from hypereosinophilic syndrome.

A 3′ splice site consensus sequence mutation in the intron 3 of the α-galactosidase a gene in a patient with Fabry disease

SummaryFabry disease is an X-linked disorder accompanied with accumulation of glycosphingolipids resulting from the deficient activity of the lysosomal hydrolase, α-galactosidase A (α-GalA). In the present study, mRNA for α-GalA in fibroblasts from an 11-year-old Japanese patient with Fabry disease was examined using the reverse transcriptase-polymerase chain reaction (PCR). The shorter message of α-GalA was demonstrated in this patient when compared with the normal control. The complete deletion of exon 4 in the mRNA for α-GalA in the patient was disclosed by analysis of cDNA with restriction enzyme digestion and asymmetrical PCR sequencing. The direct sequencing of the genomic DNA demonstrated a single base substitution (G→A) at the 3′ end of the consensus sequence of intron 3. This mutation destroyed a splice site in the α-GalA, which produced a mutant allele. It was also shown that the mother of the patient had this mutant as well as normal alleles as a heterozygote.

Increased plasma endothelin levels in Kawasaki disease: a possible marker for Kawasaki disease.

Plasma immunoreactive endothelin (iET) levels were investigated in patients with Kawasaki disease (KD). The iET level was 2.49 ± 0.13 pg/mL in KD pa tients and 1.32±0.06 in age-matched control subjects, showing a significant increase with KD. The iET level was not increased in patients with febrile in flammatory diseases of bacterial origin without KD (non-KD group). Parame ters indicating an inflammatory reaction, such as C-reactive protein, platelet count, white blood cell count, and interleukin-6 level, were increased in the KD patients. However, they were similarly increased in the patients with febrile diseases of bacterial origin and showed no significant differences between the two groups. This study is the first to report that plasma iET levels are elevated in a disease mainly involving vasculitis. These results suggest that blood iET levels are increased in KD patients as a result of the associated vascular endo thelial damage and that iET can be a useful marker for the diagnosis of KD.