Systemic T-cell activation and IFN-γ activity in indeterminate severe hepatitis are reminiscent of hemophagocytic lymphohistiocytosis: Implications for T-cell- and IFN-γ-directed therapies.

Background: Severe hepatitis cases in children are increasingly recognized, but the exact etiology remains unknown in a significant proportion of patients. Cases of indeterminate severe hepatitis (iSH) may progress to indeterminate pediatric acute liver failure (iPALF), so understanding its immunobiology is critical to preventing disease progression. Hemophagocytic lymphohistiocytosis (HLH) is a systemic hyperinflammatory disorder associated with T-cell and macrophage activation with liver injury.

Prospective pilot trial of calcipotriene as a novel topical treatment for acute skin graft versus host disease.

Skin graft versus host disease (GVHD) can affect quality of life in hematopoietic stem cell transplant recipients. Therapeutic options for steroid-refractory GVHD are limited. We report the first prospective pilot study evaluating the topical vitamin D3 analog Calcipotriene (DOVONEX 0.

Cytokine Profile of Engraftment Syndrome in Pediatric Hematopoietic Stem Cell Transplant Recipients.

The biology of engraftment syndrome is poorly understood, and the degree of overlap with acute graft-versus-host disease (GVHD) is unclear. To understand engraftment syndrome better, plasma cytokine profiles were evaluated in 56 pediatric allogeneic bone marrow transplant recipients before transplant, on the day of stem cell infusion, and weekly until day +100. Patients were divided into 4 groups: those with isolated engraftment syndrome (n = 8), acute GVHD (n = 12), both engraftment syndrome and acute GVHD (n = 4), and neither engraftment syndrome nor acute GVHD (n = 32).

Protection of mice against rotavirus challenge following intradermal DNA immunization by Biojector needle-free injection.

Mucosal administration (intranasal or oral) of a VP6 rotavirus vaccine to mice consistently elicits high levels of protection after rotavirus challenge (93->99% reductions in fecal rotavirus shedding) but only when co-administered with an effective adjuvant such as LT(R192G). Here, we showed that Biojector needle-free injection of VP6-encoded plasmids also induced protection (85-93%) when they were co-administrated with LT(R192G)-encoded plasmids. A reduction in the amount of VP6 plasmid from 50 to 10 microg reduced protection from 93 to 70%, but the immunized mice remained significantly (P<0.

Association of gamma interferon and interleukin-17 production in intestinal CD4+ T cells with protection against rotavirus shedding in mice intranasally immunized with VP6 and the adjuvant LT(R192G).

Mucosal immunization of mice with chimeric, Escherichia coli-expressed VP6, the protein that comprises the intermediate capsid layer of the rotavirus particle, together with attenuated E. coli heat-labile toxin LT(R192G) as an adjuvant, reduces fecal shedding of rotavirus antigen by >95% after murine rotavirus challenge, and the only lymphocytes required for protection are CD4+ T cells. Because these cells produce cytokines with antiviral properties, the cytokines whose expression is upregulated in intestinal memory CD4+ T cells immediately after rotavirus challenge of VP6/LT(R192G)-immunized mice may be directly or indirectly responsible for the rapid suppression of rotavirus shedding.

Mice develop effective but delayed protective immune responses when immunized as neonates either intranasally with nonliving VP6/LT(R192G) or orally with live rhesus rotavirus vaccine candidates.

Rotavirus vaccines are delivered early in life, when the immune system is immature. To determine the effects of immaturity on responses to candidate vaccines, neonatal (7 days old) and adult mice were immunized with single doses of either Escherichia coli-expressed rotavirus VP6 protein and the adjuvant LT(R192G) or live rhesus rotavirus (RRV), and protection against fecal rotavirus shedding following challenge with the murine rotavirus strain EDIM was determined. Neonatal mice immunized intranasally with VP6/LT(R192G) were unprotected at 10 days postimmunization (dpi) and had no detectable rotavirus B-cell (antibody) or CD4(+) CD8(+) T-cell (rotavirus-inducible, Th1 [gamma interferon and interleukin-2 {IL-2}]-, Th2 [IL-5 and IL-4]-, or ThIL-17 [IL-17]-producing spleen cells) responses.

Induction of immune responses and partial protection in mice after skin immunization with rotavirus VP6 protein and the adjuvant LT(R192G).

Oral or intranasal administration of mice with rotavirus VP6/LT(R192G) vaccine induces between 95 and 99% protection against fecal shedding of rotavirus after challenge. However, mucosal administration of LT(R192G) is controversial. Subcutaneous, intradermal or Biojector injection induced high titers of serum VP6-specific IgG, eliciting only partial to no protection (73, 0 and 26%, respectively), while transcutaneous delivery using gauze pad induced both poor immune responses and no protection (13%).

IL-4 exacerbates anaphylaxis.

We evaluated whether IL-4, a cytokine critical for inducing allergic responses, also contributes to the effector phase of allergy. Pretreatment of mice with IL-4 or the related cytokine, IL-13, rapidly and dramatically increased the severity of anaphylaxis induced by cross-linking Fc(epsilon)RI or FcgammaRIII. This effect was inhibited by endogenously produced IFN-gamma, was T cell-, B cell-, and common gamma-chain-independent, and required IL-4Ralpha and Stat6.