Mucosal defense against gastrointestinal nematodes: responses of mucosal mast cells and mouse mast cell protease 1 during primary strongyloides venezuelensis infection in FcRgamma-knockout mice

A possible role for the gamma subunit of immunoglobulin Fc receptors (FcR) in mucosal defenses against intestinal nematode parasites was studied using age-matched FcRgamma-knockout (FcRgamma(-/-)) and wild-type (FcRgamma(+/+)) C57BL/6 mice. Mice were infected subcutaneously with 3,000 infective larvae of Strongyloides venezuelensis, and the degree of infection was monitored by daily fecal egg counts and adult worm recovery on days 8 and 13 postinfection. Mucosal mast cell (MMC) responses were assayed by in situ intestinal mast cell counts in stained histological sections of the jejunum and by measuring mouse mast cell protease 1 (MMCP-1) release in serum using sandwich enzyme-linked immunosorbent assay. FcRgamma(-/-) mice had significantly higher egg counts (P<0.01) and numbers of adult worms (P<0.05) than FcRgamma(+/+) mice, but mastocytosis and serum MMCP-1 release were comparable. It was concluded that MMCP-1 release may be spontaneous, does not depend on mast cell degranulation via the FcRgamma signaling system, and appears to play no role in the expulsion of S. venezuelensis. The delay in worm expulsion in the FcRgamma(-/-) mice might be related to inability of the MMC to degranulate and release effector molecules other than MMCP-1, since FcRgamma deletion abrogates mast cell degranulative responses.     

The ultrasound examination of the deep vein thrombosis

Ultrasonography is very useful for detection of deep vein thrombosis. The purpose of this paper is to show a method for detecting them efficiently by high resolution transducer and color Doppler system. We examined patients in the supine and prone positions. To detect the venous flow easily and differentiate thrombi from simple venous dilatation, some maneuvers are useful; one is pushing the vein area using the transducer on examination, the second is breathing overload, and the last is so-called milking. We can find throombi in the external iliac or femoral veins of patients who have symptoms of lower leg swelling, however, we need to better detect venous thrombi in the lower leg in patients with a history of pulmonary embolism. Because deep venous thrombi are increasing, the role of ultrasound will expand in the future.     

Sequence analysis of the germ-line VH gene corresponding to a nephritogenic antibody in MRL/lpr lupus mice.

In order to investigate the genetic origin of nephritogenic antibodies in MRL/Mp-lpr/lpr (MRL/lpr) lupus mice, we isolated the germ-line heavy chain variable region (VH) gene corresponding to the nephritogenic antibody, B1, derived from an unmanipulated MRL/lpr mouse. Injection of this antibody into C.B-17/Icr-scid/scid mice resulted in the generation of wire loop-like glomerular lesions resembling those of lupus nephritis. Nucleotide sequences of this germ-line VH gene showed no replacement mutation in the VH region of the B1 antibody. Furthermore, this gene was identical to that found in the C3H/HeJ-lpr/lpr strain of mice. Our results suggest that germ-line VH genes can encode nephritogenic antibodies without somatic mutation, even in a mouse strain not prone to lupus.     

B7.2-Ig fusion proteins enhance IL-4-dependent differentiation of tumor-sensitized CD8+ cytotoxic T lymphocyte precursors

The B7/CD28 co-stimulatory pathway plays a critical role in T cell activation and differentiation. Our previous study demonstrated that administration of B7.2-Ig fusion proteins to tumor-bearing mice elicits IL-4-dependent, CD8+ T cell-mediated tumor regression. Here, we investigated whether B7.2-Ig stimulation of tumor-sensitized CD8+ CTL precursors during in vitro antigen re-sensitization actually results in their differentiation into mature CTLs and if so, whether such a process depends on IL-4 signals. Splenocytes from tumor-sensitized (tumor-bearing or tumor-immunized) mice exhibited low levels of anti-tumor CTL responses upon culturing alone, but induced strikingly enhanced CTL responses when stimulated in vitro with B7.2-Ig fusion proteins. Because CTLs were not generated from normal splenocytes even by B7.2-Ig stimulation, the expression of the B7.2-Ig effect required the in vivo tumor sensitization of CD8+ CTL precursors. Administration of anti-CD4 or anti-CD40 ligand (CD40L) to mice before tumor sensitization resulted in almost complete inhibition of CTL responses generated in the subsequent culture containing B7.2-Ig. In contrast, anti-IL-4 did not influence in vivo tumor sensitization required for CTL induction. However, B7.2-Ig stimulation of tumor-sensitized splenocytes enhanced IL-4 production and neutralization of this IL-4 with anti-IL-4 potently down-regulated CTL responses. These results indicate that B7.2-Ig enhances IL-4-dependent differentiation of anti-tumor CD8+ CTL precursors that can be sensitized in vivo depending on collaboration with CD4+ T cells involving CD40L function.     

Calcium pump expression in human bone and soft tissue tumours

Ninety-one cases of human bone and soft tissue tumours were studied for calcium pump expression by strepto-avidin-biotin immunohistochemical staining with a monoclonal antibody against sarcoplasmic reticulum calcium-ATPase (mAb6F5). Two out of 5 cases of embryonal rhabdomyosarcoma, 1 out of 5 cases of biphasic synovial sarcoma, 4 of 4 cases of chordoma and all of 3 chondrosarcoma cases were positive for mAb6F5. Although this novel monoclonal antibody can be used as a marker of myogenic tumours, the present positive result for endoplasmic reticulum calcium-ATPase (calcium pump) in other tumours including chordoma, chondrosarcoma and synovial sarcoma indicates a wider immunoreactivity. The findings further suggest that intracellular calcium may play an important role in cell proliferation and/or differentiation.     

Modulation of B-cell abnormalities in lupus-prone (NZB x NZW)F1 mice by normal bone marrow-derived B-lineage cells.

(NZB x NZW)F1(NZB/WF1) mice spontaneously develop an autoimmune disease characterized by abnormality of haemopoietic stem cells. The present study examined a possible regulatory cell interaction between NZB/WF1 and normal bone marrow cells using radiation-induced chimeras. We demonstrated that the ability of NZB/WF1 bone marrow cells to transfer the typical disease with hypergammaglobulinemia including autoantibodies into lethally irradiated normal recipients was prevented by cotransfer of bone marrow from normal CBA/J mice but not from xid CBA/N mice carrying a selective defect in B-cell function. Flow cytometric analysis revealed that the generation of NZB/WF1 cells was reduced in the mixed chimeras given CBA/J but not CBA/N bone marrow cells. Interestingly, radiation chimeras reconstituted with a mixture of NZB/WF1 bone marrow and CBA/J splenic B cells did not show elevation of serum immunoglobulin levels, although most of the spleen cells were dominated by NZB/WF1 cells. On the other hand, NZB/WF1 B cells maturated in vivo in the presence of CBA/J bone marrow or splenic B cells lost the hyper-responsiveness to lipopolysaccharide (LPS) in the autoantibody production in vitro. These results suggest that radiosensitive normal B-lineage cells have the regulatory activity to ameliorate the hypergammaglobulinemia of NZB/WF1 mice by reducing the generation of NZB/WF1 B cells and/or by correcting their hyper-responsiveness, and that NZB/WF1 mice may have a defect(s) in the regulatory cell function. In addition, CBA/J splenic B cells were shown to modulate the B-cell abnormality even when injected into non-irradiated NZB/WF1 mice manifesting autoimmunity.     

Diminution of experimental autoimmune uveoretinitis (EAU) in mice depleted of NK cells

To evaluate the potential role of NK1.1 (CD161c) cells in autoimmune uveoretinitis, we treated experimental autoimmune uveoretinitis (EAU)-susceptible mice with anti-CD161c antibodies (PK136) to deplete natural killer (NK) cells. Injection of anti-CD161c antibodies deleted NK cells from the peripheral blood of EAU-susceptible mice. The T cell proliferative response against the ocular autoantigen K2 was not suppressed in mice treated with anti-CD161c antibody when compared with T cells from control mice. Although mice treated with anti-CD161c developed EAU, the clinical severity on days 17 and 19 after induction of EAU was significantly mild in anti-CD161c-treated mice compared with control mice. In addition, the histopathological severity of EAU was significantly milder in mice treated with anti-CD161c antibodies than controls 21 days after induction of EAU. Our results indicate that the severity of EAU is augmented by NK1.1(+) NK cells.     

An immunodominant haptenic epitope of carbamazepine detected in serum from patients given long-term treatment with carbamazepine without allergic reaction

An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera.     

Immunoregulatory defects of V alpha 24V+ beta 11+ NKT cells in development of Wegener's granulomatosis and relapsing polychondritis

The frequency of either CD4(-)8(-) (double negative; DN) or CD4(+) V alpha 24(+)V beta 11(+) NKT cells, the expression of CD1d and the binding of CD1d-tetramer loaded with alpha-galactosylceramide (alpha-GalCer) to NKT cells were analysed in peripheral blood mononuclear cells (PBMCs) of patients with Wegener's granulomatosis (WG), relapsing polychondritis (RP) and healthy subjects (HS). DN and CD4(+) V alpha 24(+)V beta 11(+) NKT cells as well as CD1d-alpha-GalCer tetramer-positive NKT cells, were significantly decreased in number in both WG and RP patients compared to those from HS. When cytokine profiles were analysed in these PBMCs upon stimulation with phorbol ester and calcium ionophore, CD4(+) T cells from patients with WG and RP exhibited a Th1 bias, whereas CD4(+) NKT cells from WG patients in remission showed a Th2 bias. These findings suggest that NKT cells (especially CD4(+) NKT cells) play a regulatory role in Th1 autoimmunity in patients with WG and RP. The reduction in NKT cell counts appears to be associated with the low responsiveness to alpha-GalCer. The dysfunction of NKT cells to recognize ligands such as alpha-GalCer may also contribute to the defects observed in NKT cells from WG and RP patients.