Allergen-Induced Migration of Human Cells in Allergic Severe Combined Immunodeficiency Mice

Recently, we have shown that severe combined immunodeficiency (SCID) mice, intraperitoneally reconstituted with peripheral blood mononuclear cells (PBMC) from Dermatophagoides pteronyssinus ( Dpt )-sensitive patients, produced human IgE and developed a pulmonary inflammatory-type reaction after exposure to allergen aerosol. In order to understand the potential mechanisms involved in the human cell migration in SCID mice, we analysed their phenotypic profile in the lungs, spleen and thymus, 2 months after Dpt inhalation. The human cell recruitment in these organs was found to be allergen-dependent as CD45⁺ human cells were only detected in hu-SCID mice after Dpt exposure. The composition of the pulmonary human T-cell infiltrate, preferentially memory (CD45RO), activated (human leucocyte antigen (HLA)-DR) and CD4⁺ cells, was similar to that described in asthmatic patients. However, CD20⁺ B cells were predominately recruited in the spleen and thymus and may be IgE-producing cells in the spleen. In the lungs, the percentage of human leucocytes expressing the α-chain of the lymphocyte function-assiciated antigen-1 (LFA-1) (CD11a) was higher than those of CD49d⁺ or CD54⁺ cells, in contrast to the spleen and thymus, suggesting a potential role of LFA-1 in the human cell migration towards SCID mice lung. In conclusion, this model could be useful in the study of factors implicated in the cellular migration towards the lymphoid organs during an allergic reaction.     

Severe Suppression of the B-cell System has No Impact on the Maturation of Natural Killer Cells in Mice

Mice were treated with a heterologous anti-IgM serum to obtain B-cell-deprived mice. Spleen cells from normal and B-cell-deprived mice were tested in three different cytolytic systems: natural killer cells (NK); antibody-dependent cell-mediated cytolysis (ADCC) against an NK-sensitive tumour, P815; and ADCC against chicken erythrocytes. The impact of administration of an interferon-inducing NK enhancing agent, Tilorone, was also investigated. Whereas the cell population from B-cell-deprived mice was significantly suppressed in antibody-producing cells, the capacity to function in NK or ADCC was largely unimpaired both before and after administration of Tilorone. Our results would imply that mature B cells play no significant role in either the maturation of the NK cells or the expression of their cytolytic ability. Furthermore, effector cells for both NK and ADCC against antibody-coated tumour target cells were found to be distinct from those functioning in ADCC against chicken erythrocytes.     

Interleukin-6 Overexpression Cannot Generate Serious Disorders in Severe Combined Immunodeficiency Mice

C57BL/6 human interleukin-6 (IL-6) transgenic mice develop mesangial proliferative glomerulonephritis with massive IgG1 plasmacytosis and die of renal failure in early life. To test whether the IL-6 overexpression could cause development of mesangial proliferative glomerulonephritis without plasmacytosis or promote proliferation of immature B cells that have not undergone immunoglobulin gene rearrangement, the IL-6 transgene was introduced into mice with severe combined immunodeficiency (SCID). In the immunocompetent littermate IL-6 transgenic mice, there were various symptoms such as plasmacytosis, nephropathy, anemia, and thrombocytosis, accompanied by marked increases in serum IL-6 levels as they aged. All these mice died by 25 weeks of age. In contrast, the SCID-IL-6 transgenic mice had no such abnormalities, except certain hematological changes, although the transgene was expressed in various tissues. In these mice, the serum IL-6 levels were 10- to 15-fold higher than those in the nontransgenic mice, and they remained constant throughout their lives. Furthermore, there were no signs of lymphoid development. This study demonstrates that deregulation of IL-6 expression does not stimulate cell growth or differentiation of immature B cells, and thus does not result in plasmacytosis and age-related increases in IL-6 production, and also does not generate mesangial proliferative glomerulonephritis.     

Histaminergic Regulation of Natural Killer Cell-Mediated Clearance of Tumour Cells in Mice

Treatment of Swiss albino mice with histamine enhanced the clearance of natural killer (NK)-cell sensitive YAC-1 lymphoma and B16/F10 melanoma cells from lung tissue in vivo , but did not affect the elimination of NK-cell-insensitive P815mastocytoma cells. The effect of histamine was apparently mediated by H₂-type histamine receptors (H₂R) since it was blocked by ranitidine, an H₂R antagonist. Histamine did not affect clearance of tumour cells in animalsdepleted of NK cells in vivo by treatment with antibodies to asialo-GM1 or NK1.1. The effect of histamine was time-dependent: pretreatment with histamine for 3 h significantly augmented the clearance of YAC-1 cells, whereas, pretreatmentwith histamine for 5 min was ineffective. Histamine potentiated the anti-tumour properties of NK-cell activators such as interleukin-2 (IL-2) or interferon-α (IFN-α) in vivo . None of these lymphokines significantly affected theclearance of YAC-1 cells unless animals were concomitantly treated with histamine. Treatment with ranitidine alone reduced the in vivo clearance of YAC-1 cells from lungs but did not affect the clearance of NK-cell-insensitive P815 cells. Effects of ranitidine on NK-cell function in vivo were not shared by a chemical control to ranitidine, AH20239AA, thus indicating that the inhibition of NK-cells results from H₂R antagonism rather than non-specific toxicity. It is concludedthat histaminergic mechanisms may be involved in the regulation of NK cell function in vivo     

The Effect of Natural Killer Cell Killer Ig-Like Receptor Alloreactivity on the Outcome of Bone Marrow Stem Cell Transplantation for Severe Combined Immunodeficiency (SCID)

Natural killer (NK) cell alloreactions against recipient cells in the setting of bone marrow transplantation have been associated with decreased rates of graft-versus-host disease (GVHD) and improved survival in transplant recipients with myeloid leukemia. These alloreactions are predicted by the absence of recipient HLA class I ligands for donor inhibitory killer Ig-like receptors (KIR). We hypothesized that donor NK cell alloreactions against recipient cells may affect the development of T and B-cell functions and incidence of GVHD in infants with severe combined immunodeficiency (SCID). Of the 156 patients with SCID who had received related bone marrow transplants without pretransplant chemotherapy or posttransplant GVHD prophylaxis, 137 patient-donor pairs were evaluated for the absence of recipient HLA class I ligands for donor inhibitory KIR. Analysis showed that the absence of a KIR ligand had no effect on the incidence or severity of GVHD (RR [corrected] = 0.95, p = 0.84), development of T-cell function (RR [corrected] = 1.05, p = 0.69), production of IgA (p = 0.46) or IgM (p = 0.33), or on 5-year survival (RR [corrected] = 1.21, p = 0.10). Further, in patients possessing native NK cells, the absence of KIR ligands in donors for recipient-inhibitory KIR did not alter transplantation outcomes. This study suggests that inhibitory KIR/HLA interactions do not play a significant role in bone marrow transplantation for SCID.     

Gene Therapy in Infants with Severe Combined Immunodeficiency

Severe combined immunodeficiencies (SCID) are rare disorders that represent paediatric medical emergencies, as the outcome for affected patients can easily be fatal unless proper treatment is performed. The only curative treatment for SCID is reconstitution of the patient's immunity. For more than 30 years, allogeneic bone marrow transplantation (BMT) has been extremely successful for SCID. However, BMT often results in only incomplete restoration of B cell function in treated patients, especially when haploidentical donors are used. In addition, BMT can be associated with severe complications such as graft-versus-host disease (GVHD). Alternative forms of therapy for SCID are therefore desirable. Genetic correction of peripheral T lymphocytes and/or haematopoietic stem cells (HSCs) by retrovirally mediated gene transfer has been attempted for patients with SCID due to adenosine deaminase deficiency, the first genetic disease targeted in clinical gene therapy trials with very limited success, overall. After these pioneer trials, recent progress has led to significant improvement of gene transfer techniques and better understanding of HSC biology which has culminated in the recent success of a gene therapy trial for patients affected with X-linked SCID (X-SCID). In this trial, patients with X-SCID received autologous bone marrow stem/progenitor cells which had been retrovirally transduced with a therapeutic gene. Based on the current follow-up, the overall efficacy of this gene therapy procedure is to be considered similar to or even better than that achievable by allogeneic BMT, because patients were not exposed to the risks of GVHD. Although these exciting results have clearly demonstrated that gene therapy is a feasible therapeutic option for X-SCID, they have also raised important questions regarding the long-term outcome of this experimental procedure and the possibility of translating this success into applications for other forms of SCID.     

Dendritic Cell Immunotherapy Combined with Cytokine-Induced Killer Cells Effectively Suppresses Established Hepatocellular Carcinomas in Mice

Background: The response of hepatocellular carcinoma (HCC) to immunotherapy is often disappointing and new strategies are clearly needed. The aim of the present study was to investigate whether cytokine-induced killer (CIK) cells combined with a dendritic cell vaccination enhanced cytotoxicity against hepatocarcinoma tumor cells in an in vivo animal model.

Methods: CIKs and DCs were prepared from C3H/HeJ mice by conventional methods, the dendritic cell (DC) pulsed with a MH134 cell lysate, DC or CIK alone were used as controls. Cell phenotypes were analyzed by flow cytometry, cytokine secretion levels were determined by enzyme-linked immunosorbent assay (ELISA), and cytotoxicity was assessed by means of an in vitro lactate dehydrogenase (LDH) release assay. A mouse hepatocarcinoma cell MH134-bearing mice model was established to test the in vivo anti-tumor efficacy of the system.

Results: CIK cells combined with DC therapy resulted in significant inhibition of tumor growth compared with the control group, whereas the decrease in tumor growth in mice that had been treated with CIK or DC alone did not reach the level of statistical significance. The combination therapy led to a further increase in the population of cytotoxic T cells (CTLs) in vivo, compared to the CIK or DC alone therapy. In addition, the combination therapy significantly enhanced cytotoxic activity against MH134 cells.

Conclusion: Taken together, these results show that a DC + CIK vaccination is more effective than DC or CIK alone therapy for the treatment of hepatocarcinoma cancer.     

Characterization of Clonality of Epstein-Barr Virus-Induced Human B Lymphoproliferative Disease in Mice with Severe Combined Immunodeficiency

To improve the diagnostic accuracy and understanding of the pathogenesis of lymphoproliferative diseases (LPDs) occurring in immunosuppressed transplant recipients (post-transplantation LPD), clonality of Epstein-Barr virus-induced human LPDs in mice with severe combined immunodeficiency was examined by analyzing: 1) human immunoglobulin genes and their products, 2) the clonality of Epstein-Barr virus DNA, and 3) genetic alteration of c-myc or bcl-2 genes. A spectrum of clonality was found in the LPDs comparable with that reported for post-transplantation LPDs, although rearrangements of c-myc or bcl-2 genes were not detected. It is confirmed that this system is useful in terms of clonality for understanding the early phases in the pathogenesis of post-transplantation LPD or LPD in immune deficient patients.     

KRN7000 Reduces Airway Inflammation via Natural Killer T Cells in Obese Asthmatic Mice

Although natural killer T cells (NKT cells) are altered in obese asthmatic mice, their function remains completely unclear. To further explore the potential mechanism of NKT cells in airway inflammation of obesity-associated asthma, we examined the effects of α-galactosylceramide (KRN7000) on airway inflammation in obese asthmatic mice. Male C57BL/6J mice were divided into five groups: (1) control; (2) asthma; (3) A + KRN, asthma with KRN7000; (4) obese asthma; and (5) OA + KRN, obese asthma with KRN7000. Cytometric bead array (CBA) was used to detect interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) in the serum. Flow cytometry was used to detect NKT cells and CD69⁺ NKT cells. Airway inflammation was observed in pathological sections, and calmodulin (CaM) expression was observed by immunohistochemistry in lung tissues. Airway inflammation in the obese asthma group was more severe than that of the asthma group. Airway inflammation of the OA + KRN group was reduced more than that of the A + KRN group. CD69+ NKT cells were only significantly reduced in the OA + KRN group. The levels of serum IFN-γ and TNF-α increased more in the OA + KRN group than in the A + KRN group. CaM is widely expressed in the cytoplasm of the lung tissues and was sharply decreased in the OA + KRN group. KRN7000 can significantly reduce airway inflammation in obesity-associated asthma by regulating NKT cell cytokine secretion and intracellular calcium. These results may contribute to the development of novel therapeutic approaches.

     

Stress Causes Reduced Natural Killer Activity in Mice

The natural killer (NK) activity of spleen cells from C57B1/10 mice subjected to standardized stress conditions was reduced when compared with that of untreated controls. Both the total number of nucleated spleen cells and their cytotoxic activity against an NK-sensitive target were reduced. The reduction appeared after induction of stress, and the NK activity was reduced throughout an 8-day stress period.     

Fetal Thymus Transplantations in Severe Combined Immunodeficiency

Two brothers with severe combined immunodeficiency were treated with repeated transplantations of fetal thymus tissue. The first patient was not treated until he was critically ill, and the intramuscular transplants had no effect. He died at 11 months of age of overwhelming pneumonia. At postmortem examination a transplanted thymus seemed viable. In the second patient an intramuscular transplant had no effect, but three subsequent intraperitoneal transplants led to transient increase in circulating T lymphocytes with a concomitant fall in B lymphocytes. The results suggested an additive effect of each transplant. However, delayed hypersensitivity skin tests and in vitro mitogen responses were not influenced. Initially, transfer factor was given, and fetal liver was administered intraperitoneally together with the last thymic transplant. Neither of these measures had any observed effect, and this patient, similarly, died of pneumonia at nearly 12 months of age.     

Recurrent Chronic HEV in Severe Combined Immunodeficiency

Journal of Clinical Immunology -