First case report of paragonimiasis in a Malaysian man

Paragonimiasis is an infection caused by Paragonimus, a lung fluke and is acquired by eating raw or undercooked crustaceans containing the infective metacercariae. Herein, we report a case of paragonimiasis in a Malaysian man who presented with incidental findings from chest radiographs. Examination of his biopsied lung tissue and sputum specimen revealed Paragonimus sp. eggs, whereas stool examination showed the presence of Giardia cysts. Patient was succesfully treated with praziquantel and metronidazole respectively.

Phase I study of samalizumab in chronic lymphocytic leukemia and multiple myeloma: blockade of the immune checkpoint CD200

PURPOSE

Samalizumab is a novel recombinant humanized monoclonal antibody that targets CD200, an immunoregulatory cell surface member of the immunoglobulin superfamily that dampens excessive immune responses and maintains self-tolerance. This first-in-human study investigated the therapeutic use of samalizumab as a CD200 immune checkpoint inhibitor in chronic lymphocytic leukemia (CLL) and multiple myeloma (MM).

EXPERIMENTAL DESIGN

Twenty-three patients with advanced CLL and 3 patients with MM were enrolled in an open-label phase 1 study (NCT00648739). Patients were assigned sequentially to one of 7 dose level cohorts (50 to 600 mg/m²) in a 3 + 3 study design, receiving a single dose of samalizumab intravenously once every 28 days. Primary endpoints were safety, identification of the maximum tolerated dose (MTD), and pharmacokinetics. Secondary endpoints were samalizumab binding to CD200, pharmacodynamic effects on circulating tumor cells and leukocyte subsets, and clinical responses.

RESULTS

Twenty-one patients received > 1 treatment cycle. Adverse events (AEs) were generally mild to moderate in severity. Samalizumab produced dose-dependent decreases in CD200 expression on CLL cells and decreased frequencies of circulating CD200 + CD4+ T cells that were sustained at higher doses. The MTD was not reached. Decreased tumor burden was observed in 14 CLL patients. One CLL patient achieved a durable partial response and 16 patients had stable disease. All MM patients had disease progression.

CONCLUSIONS

Samalizumab had a good safety profile and treatment was associated with reduced tumor burden in a majority of patients with advanced CLL. These preliminary positive results support further development of samalizumab as an immune checkpoint inhibitor.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00648739 registered April 1, 2008.

Systemic Alanine Glyoxylate Aminotransferase mRNA Improves Glyoxylate Metabolism in a Mouse Model of Primary Hyperoxaluria Type 1

Primary Hyperoxaluria Type 1 (PH1) is an autosomal recessive disorder of glyoxylate metabolism. Loss of alanine glyoxylate aminotransferase (AGT) function to convert intermediate metabolite glyoxylate to glycine causes the accumulation and reduction of glyoxylate to glycolate, which eventually is oxidized to oxalate. Excess oxalate in PH1 patients leads to the formation and deposition of calcium oxalate crystals in the kidney and urinary tract. Oxalate crystal deposition causes a decline in renal function, systemic oxalosis, and eventually end-stage renal disease and premature death. mRNA-based therapies are a new class of drugs that work by replacing the missing enzyme. mRNA encoding AGT has the potential to restore normal glyoxylate to glycine metabolism, thus preventing the buildup of calcium oxalate in various organs. Panels of codon-optimized AGT mRNA constructs were screened in vitro and in wild-type mice for the production of a functional AGT enzyme. Two human constructs, wild-type and engineered AGT (RHEAM), were tested in Agxt^-/- mice. Repeat dosing in Agxt^-/- mice resulted in a 40% reduction in urinary oxalate, suggesting therapeutic benefit. These studies suggest that mRNA encoding AGT led to increased expression and activity of the AGT enzyme in liver that translated into decrease in urinary oxalate levels. Taken together, our data indicate that AGT mRNA may have the potential to be developed into a therapeutic for PH1.

Meeting report, “First Indian national conference on cervical cancer management - expert recommendations and identification of barriers to implementation”

Objective

In India, cervical cancer accounts for almost 14% of all female cancer cases. Although poverty continues to cast a wide net over the Indian subcontinent, the preceding three decades have borne witness to improvements in nutrition and sanitation for many citizens. However, due to an absence of a national immunization program to cover human papillomavirus (HPV) vaccination and lack of accessible cervical cancer screening, the disease is characterized by late detection, lack of access to affordable and quality health care, and high mortality rates. Treatment of cervical cancer is stage-specific and depends on the patient’s age, desire to preserve fertility, overall health, the clinician’s expertise, and accessibility to resources. There is a paucity of uniform treatment protocols for various stages of cervical cancer in India. Considering all these parameters, a need to optimize treatment paradigms for the Indian population emerged.

Methods/materials

Three expert panel meetings were held in different regions of India from 2016 to 2017. They were comprised of 15 experts from across the country, and included surgical oncologists, radiation oncologists, and medical oncologists. The panel members reviewed the literature from both national and global sources, discussed their clinical experience and local practices and evaluated current therapeutic options and management gaps for women diagnosed with cervical cancer.

Results

This article summarizes the expert opinion from these meetings. It discusses the available resources and highlights the current therapeutic options available for different cervical cancer stages: early stage disease, locally advanced tumors, recurrent/persistent/metastatic cancer. An Indian consensus governing treatment options emerged, including guidelines for use of the only approved targeted therapy in this disease, the anti-angiogenesis drug, bevacizumab.

Conclusions

The panel concluded that given the availability of state-of-the-art imaging modalities, surgical devices, radiotherapeutics, and novel agents in several population-dense urban centers, a uniform, multi-disciplinary treatment approach across patient care centers is ideal but not realistic due to cost and a paucity of third party payors for most Indian citizens. Preventative strategies including visual inspection with acetic acid to screen for precursor lesions (i.e., cervical intraepithelial neoplasia) with immediate referral for cervical cryotherapy and possible large-scale roll-out of the HPV vaccine in the near future can be expected to reduce mortality rates significantly in this country.

Efficacy of C.E.R.A. in Routine Clinical Practice for Correction of Anaemia and Maintenance of the Haemoglobin Levels in CKD Patients not on Dialysis

INTRODUCTION

C.E.R.A. reported effective correction of anaemia and was well tolerated in International studies on CKD patients not on dialysis.

OBJECTIVE

The study aimed to describe the management of renal anaemia in CKD patients not on dialysis with C.E.R.A. in routine clinical practice in India.

METHODS

This was a prospective, single-arm, open-label, multi-centre, non-interventional, Phase IV study which followed 108 CKD Stage III-IV patients, not on dialysis with Hb < 10 g/dL for correction of anaemia with C.E.R.A.

RESULTS

Of the 108 patients with Hb < 10 g/dL at baseline, 83 (90.2%) patients achieved target Hb of 10-12 g/dL and the time taken to achieve correction of anaemia was 9.6 weeks ± 6.13 weeks in the Intent-to-treat population. Haemoglobin concentration increased from 8.59 ± 0.808 g/dL pre-therapy to 10.91 ± 0.634 g/dL post-therapy. The change in mean ± SD Hb value was 2.32 ± 0.174 g/dL. Maintenance of Hb levels within the target range of Hb 10 - 12 g/dL was observed in 78.2% of ITT and 80.8% of the PP population for mean duration of 16.69 weeks. Four patients (3.7%) experienced 5 AEs and 2 patients (1.9%) experienced 3 SAEs in the safety population. As per the treating physician none of the AEs or SAEs was considered related to study drug. There were no deaths reported.

CONCLUSIONS

This study demonstrated successful correction of anaemia in Indian patients with C.E.R.A. treatment as well as maintenance of Hb levels within the target range. C.E.R.A. was well tolerated with no new safety concerns specific to the Indian population. The less frequent up to monthly dosing schedule of C.E.R.A. may offer clinicians and patients a simplified regimen of anaemia management as compared to traditional frequently administered (thrice weekly to once weekly) ESAs.

Selective blockade of the inhibitory Fcgamma receptor (FcgammaRIIB) in human dendritic cells and monocytes induces a type I interferon response program

The ability of dendritic cells (DCs) to activate immunity is linked to their maturation status. In prior studies, we have shown that selective antibody-mediated blockade of inhibitory FcgammaRIIB receptor on human DCs in the presence of activating immunoglobulin (Ig) ligands leads to DC maturation and enhanced immunity to antibody-coated tumor cells. We show that Fcgamma receptor (FcgammaR)-mediated activation of human monocytes and monocyte-derived DCs is associated with a distinct gene expression pattern, including several inflammation-associated chemokines, as well as type 1 interferon (IFN) response genes, including the activation of signal transducer and activator of transcription 1 (STAT1). FcgammaR-mediated STAT1 activation is rapid and requires activating FcgammaRs. However, this IFN response is observed without a detectable increase in the expression of type I IFNs themselves or the need to add exogenous IFNs. Induction of IFN response genes plays an important role in FcgammaR-mediated effects on DCs, as suppression of STAT1 by RNA interference inhibited FcgammaR-mediated DC maturation. These data suggest that the balance of activating/inhibitory FcgammaRs may regulate IFN signaling in myeloid cells. Manipulation of FcgammaR balance on DCs and monocytes may provide a novel approach to regulating IFN-mediated pathways in autoimmunity and human cancer.

Bortezomib disrupts tumour-dendritic cell interactions in myeloma and lymphoma: therapeutic implications

Recent studies have shown that the interactions between tumour and dendritic cells (DCs) promote clonogenic growth of lymphoproliferative tumours, particularly myeloma. The present study showed that the proteasome inhibitor, bortezomib, disrupts this interaction. Targeting the drug to DCs was required for optimal suppression of tumour growth, including primary myeloma tumour progenitors in clonogenic assays. Bortezomib lead to dose-dependent induction of apoptosis in both myeloid and plasmacytoid DCs, and the sensitivity of DCs to bortezomib was comparable with that of tumour cells. These data suggest that disruption of tumour-DC interactions may contribute to the clinical effects of bortezomib.

Frequent and specific immunity to the embryonal stem cell-associated antigen SOX2 in patients with monoclonal gammopathy

Specific targets of cellular immunity in human premalignancy are largely unknown. Monoclonal gammopathy of undetermined significance (MGUS) represents a precursor lesion to myeloma (MM). We show that antigenic targets of spontaneous immunity in MGUS differ from MM. MGUS patients frequently mount a humoral and cellular immune response against SOX2, a gene critical for self-renewal in embryonal stem cells. Intranuclear expression of SOX2 marks the clonogenic CD138⁻ compartment in MGUS. SOX2 expression is also detected in a proportion of CD138⁺ cells in MM patients. However, these patients lack anti-SOX2 immunity. Cellular immunity to SOX2 inhibits the clonogenic growth of MGUS cells in vitro. Detection of anti-SOX2 T cells predicts favorable clinical outcome in patients with asymptomatic plasmaproliferative disorders. Harnessing immunity to antigens expressed by tumor progenitor cells may be critical for prevention and therapy of human cancer.

Enhancement of clonogenicity of human multiple myeloma by dendritic cells

Infiltration by dendritic cells (DCs) is a common feature of most human tumors. Prior studies evaluating the interaction of DCs with tumors have focused largely on their immunologic properties (for review see Banchereau, J., and R.M. Steinman. 1998. Nature. 392:245–252). In this study, we show that the clonogenicity of several human tumor cell lines and primary tumor cells from myeloma patients is enhanced by their interactions with DCs. Myeloma cells cultured in the presence of DCs have an altered phenotype with an increased proportion of cells lacking terminal plasma cell differentiation marker CD138. DC–tumor interaction also leads to the up-regulation of B cell lymphoma 6 expression in myeloma cells. Effects of DCs on myeloma cells are inhibited by blockade of the receptor activator of NF-kB (RANK)–RANK ligand and B cell–activating factor–APRIL (a proliferation-inducing ligand)-mediated interactions. Together, these data suggest that tumor–DC interactions may directly impact the biology of human tumors, particularly multiple myeloma, and may be a target for therapeutic intervention.

Sustained expansion of NKT cells and antigen-specific T cells after injection of alpha-galactosyl-ceramide loaded mature dendritic cells in cancer patients

Natural killer T (NKT) cells are distinct glycolipid reactive innate lymphocytes that are implicated in the resistance to pathogens and tumors. Earlier attempts to mobilize NKT cells, specifically, in vivo in humans met with limited success. Here, we evaluated intravenous injection of monocyte-derived mature DCs that were loaded with a synthetic NKT cell ligand, α-galactosyl-ceramide (α-GalCer; KRN-7000) in five patients who had advanced cancer. Injection of α-GalCer–pulsed, but not unpulsed, dendritic cells (DCs) led to >100-fold expansion of several subsets of NKT cells in all patients; these could be detected for up to 6 mo after vaccination. NKT activation was associated with an increase in serum levels of interleukin-12 p40 and IFN-γ inducible protein-10. In addition, there was an increase in memory CD8⁺ T cells specific for cytomegalovirus in vivo in response to α-GalCer–loaded DCs, but not unpulsed DCs. These data demonstrate the feasibility of sustained expansion of NKT cells in vivo in humans, including patients who have advanced cancer, and suggest that NKT activation might help to boost adaptive T cell immunity in vivo.

NKT cell defects in NOD mice suggest therapeutic opportunities

Recent studies have reported that immunoregulatory NKT cells are defective in NOD mice and that treatment of mice with alpha-galactosylceramide that selectively stimulate NKT cells, is anti-diabetogenic. The objective of this study was to document the natural history of changes in NKT cells in various organs in NOD mice in the period up to the time of diabetes onset so that novel intervention therapies could be devised. We found that NKT cell-specific receptor (NKT-TCR) Valpha14Jalpha281 expressions by quantitative (RealTime) RT-PCR in thymus, spleen and liver of NOD male and female mice were low at 1-3 months of life compared to BALB/c and C57BL/6 mice, albeit a transient spike in levels occurred in female NOD livers at 2 months. Female pancreases showed low levels of these transcripts despite their active and destructive insulitis. In contrast, NOD males exhibited high expression of this invariant TCR in pancreas, where their insulitis was less destructive. A survey of NKT-TCR expressions in a battery of congenic, non-diabetes prone NOD strains indicated that this NKT phenotype was quite variable but higher than diabetes prone NOD. Bone marrow transplantation of NOD females from B6.NOD-H2(g7) donors raised their NKT-TCR expressions. Tuberculin administrations in the forms of BCG and CFA in a manner known to protect NOD mice from diabetes both raised NKT-TCR levels, as did the anti-inflammatory PPAR-gamma agonist rosiglitazone. These findings provide exciting therapeutic avenues to be explored in the treatment of human immune mediated type-1 diabetes where there are similar immunoregulatory lesions.

Multiple immuno-regulatory defects in type-1 diabetes

Susceptibility to immune-mediated diabetes (IMD) in humans and NOD mice involves their inherently defective T cell immunoregulatory abilities. We have followed natural killer (NK) T cell numbers in patients with IMD, both by flow cytometry using mAbs to the characteristic junctions found in the T cell receptors of this cell subtype, and by semiquantitative RT-PCR for the corresponding transcripts. Both before and after clinical onset, the representation of these cells in patients' PBMCs is reduced. We also report low numbers of resting CD4(+) CD25(+) T cells in IMD patients, a subset of T cells shown to have important immunoregulatory functions in abrogating autoimmunities in 3-day thymectomized experimental mice. Whereas a biased Th1 to Th2 cytokine profile has been suggested to underlie the pathogenesis of IMD in both species, we found defective production of IFN-gamma in our patients after in vitro stimulation of their PBMCs by phorbol-myristate acetate and ionomycin and both IFN-gamma and IL-4 deficiencies in V(alpha)24(+) NK T-enriched cells. These data suggest that multiple immunoregulatory T (Treg) cell defects underlie islet cell autoimmunity leading to IMD in humans and that these lesions may be part of a broad T cell defect.

NKT cells and type-1 diabetes and the "hygiene hypothesis" to explain the rising incidence rates

Immune-mediated (type-1) diabetes (IMD) is a multigenetic disease that is strongly influenced by the environment. Whereas the incidence rates are steadily rising worldwide, less than half of affected identical twins ever become concordant for IMD or even beta-cell autoimmunity. Worldwide, it is the tropical regions of the world that are replete in infectious and parasitic diseases that are the least affected. Repeated efforts to identify the putative inductive agents for beta-cell autoimmunity have proved unrewarding. Rather, we suggest that some environments are less protective than others and argue that it is the fall in incidences of infectious diseases and intestinal parasites that are likely responsible for the rise in autoimmune diseases like IMD in the West. Nonobese diabetic (NOD) mice reared in gnotobiotic environments have only worsened diabetes, while recent studies suggest that multiple defects in immune tolerance to self must be present before IMD can develop in the human or mouse. We speculate herein that the deficiency in natural killer T (NKT) cells in IMD in both species may be both genetic and environmentally influenced, predisposing to pancreatic beta-cell autoimmunity through a dysfunction of immunoregulatory T cells, with defective peripheral control of islet cell protein autoreactive cytotoxic CD8+ T cells. The encouraging results in NOD mice using alpha-galactosylceramide to stimulate NKT cells now warrant trials with this and other glycolipid NKT cell-stimulating agents in humans. Since it has become apparent that autoimmune diseases such as IMD are the result of an underlying immunodeficiency state, we strongly argue that its effective prevention will likely come through the use of immunostimulation and not through side effect-prone immunosuppression.

Multiple immuno-regulatory defects in type-1 diabetes

Susceptibility to immune-mediated diabetes (IMD) in humans and NOD mice involves their inherently defective T cell immunoregulatory abilities. We have followed natural killer (NK) T cell numbers in patients with IMD, both by flow cytometry using mAbs to the characteristic junctions found in the T cell receptors of this cell subtype, and by semiquantitative RT-PCR for the corresponding transcripts. Both before and after clinical onset, the representation of these cells in patients' PBMCs is reduced. We also report low numbers of resting CD4(+) CD25(+) T cells in IMD patients, a subset of T cells shown to have important immunoregulatory functions in abrogating autoimmunities in 3-day thymectomized experimental mice. Whereas a biased Th1 to Th2 cytokine profile has been suggested to underlie the pathogenesis of IMD in both species, we found defective production of IFN-gamma in our patients after in vitro stimulation of their PBMCs by phorbol-myristate acetate and ionomycin and both IFN-gamma and IL-4 deficiencies in V(alpha)24(+) NK T-enriched cells. These data suggest that multiple immunoregulatory T (Treg) cell defects underlie islet cell autoimmunity leading to IMD in humans and that these lesions may be part of a broad T cell defect.

Phenobarbital, oxazepam and Wyeth 14,643 cause DNA damage as measured by the Comet assay

Although phenobarbital, oxazepam and Wyeth 14,643 are carcinogens that do not form DNA adducts, they induce mutations in the Big Blue transgenic mouse model. The mutations produced by these compounds were predominantly G-->T and G-->C transversions that we suspect arose from oxidative damage to DNA. To test this, we employed the single cell electrophoresis (Comet) assay that detects alkali-labile lesions in cells sustaining DNA damage. Human myeloid leukemia K562 cells were treated with non-cytotoxic doses of the above compounds for 3 h, then placed on slides containing low melting point agarose. Cells were lysed, exposed to alkaline buffer, electrophoresed and analyzed by microscopy for the existence of DNA damage. Extensive DNA damage, most likely due to the existence of single- and double-strand breaks and apurinic/apyrimidinic (AP) sites, was observed in cells exposed to oxazepam (1 mM) and Wyeth 14,643 (0.5 mM). On the other hand, damage of this sort was not observed in cells exposed to phenobarbital (1 mM). However, the addition of S9 liver extracts to cells exposed in the presence of phenobarbital resulted in significant amounts of DNA damage. We conclude from these studies that two of the three compounds evaluated in this study mediate their mutagenic effects through oxidative stress, but that the mechanism of DNA damage caused by phenobarbital differs from that elicited by oxazepam and Wyeth 14,643.

Islet cell autoimmunity in youth onset diabetes mellitus in Northern India

We characterised a consecutive cohort of 132 youth onset diabetic individuals (age at onset<30 years, mean duration of disease 5.5+/-6.0 years) from North India, by serological determination of the determination of the islet cell autoantibodies, GAD(65) and IA2, and clinically for coexisting autoimmune thyroid disease, malnutrition and pancreatic calcification. Five types of diabetes were delineated: Type 1 (37%), ketosis resistant (32%), Type 2 (13%), fibrocalculous pancreatopathy (11%) and autoimmune polyglandular syndrome (7%). C-peptide response to glucagon was assessed in a representative subset of 50 patients with Type 1, ketosis resistant, and autoimmune polyglandular syndrome. A total of 22.4% of Type 1 and 30% of autoimmune polyglandular syndrome subjects showed both GAD(65) plus IA-2 autoantibody positivity, significantly more than the 4.7% positivity shown by the ketosis resistant type. However, GAD(65) antibody positivity alone was seen in 38% of ketosis resistant subjects which was significantly more than the 14.2 and 10% positivity seen in Type 1 and autoimmune polyglandular groups, respectively. The fibrocalculous pancreatopathy group showed GAD(65) plus IA-2 autoantibody positivity in 14.2% and GAD(65) autoantibody alone positivity in 7.1%. 26 and 60%, respectively, of the Type 1 and autoimmune polyglandular syndrome groups had thyroid microsomal autoantibody positivity. Type 1 showed significantly less C-peptide response to glucagon when compared to the ketosis resistant and autoimmune polyglandular syndrome groups. The controls and Type 2 diabetic individuals tested negative for islet cell autoimmunity markers. These findings demonstrate a role of islet cell autoimmunity in the pathogenesis of four out of the five clinical types of youth onset diabetes seen in North India.

Autoimmune hypogonadism as part of an autoimmune polyglandular syndrome

The most compelling case for autoimmune mediated hypogonadism occurs when ovarian failure is part of an autoimmune polyglandular syndrome (APS). In patients with the rare, recessively inherited type 1 APS (APS-1), characterized by the triad of chronic mucocutaneous moniliasis, hypoparathyroidism, and Addison's disease, primary amenorrhea (elevated pituitary gonadotropins) or oligomenorrhea and infertility are constant features. Ovarian failure is associated with autoantibodies to steroid hormone secreting cells in the adrenal cortex, Leydig cells of the testes, granulosa/thecal cells of the Graffian follicles, corpus luteum, and the syncytiotrophoblast of the placenta. These autoantibodies react with 3 P450 enzymes involved with steroidogenesis, namely, 21-hydroxylase (adrenal specific), 17 alpha-hydroxylase, and the side chain cleavage enzyme. Recently the 14 exon, APS-1 (autoimmune regulator or AIRE) gene has been cloned (chr. 21p22.3), and multiple mutants discovered. Parents who are obligatory heterozygotes for a single mutant gene lack clinical features of APS-1. They also do not develop APS-1 autoantibodies. Thus, hypogonadal patients without features of APS-1 are unlikely to have AIRE gene mutations. In the more common APS-2/3, characterized by combinations of autoimmune thyroid disease, immune mediated type 1 diabetes, vitiligo, pernicious anemia, and Addison's disease (type 2, not type 3), ovarian disease may be seen. In primary hypogonadism outside of the context of an APS, these autoantibodies are rare.

Diabetes vaccines: a future to be realized

Immune-mediated (type 1) diabetes mellitus (IMD) is an autoimmune disease resulting from the chronic destruction of pancreatic islet cells by autoreactive T lymphocytes. Although there has been much advancement in diabetes management, targeting the precise etiology of the disease process has remained elusive. Recent progress in the understanding of the immunopathogenesis of IMD, however, has led to new intervention strategies, especially antigen-based therapies given as altered peptide ligands (APLs) or as vaccines. Instead of using immunosuppressive agents to suppress an already dysfunctional immune system, antigen specific vaccines or even non-antigen specific immunostimulants present a unique opportunity to boost regulatory function and thereby regain tolerance to self. We discuss here the pathogenesis of IMD as it relates to therapeutic possibilities, review various intervention strategies that have been successful in rodent models, and then present recent progress in human trials of diabetes intervention and prevention through vaccine prototypes.

The human leukocyte antigen HLA DRB3*020/DQA1*0501 haplotype is associated with Graves' disease in African Americans

Information on genetic susceptibility to Graves' disease in African Americans is limited. We studied DRB1, DQB1, DRB3 subtypes, DQA1*0501, DQA1*0201, and CTLA-4 polymorphisms in 49 African American patients with adult onset Graves' disease and 47 racially-matched controls using PCR-based sequence-specific priming methods. There were no significant differences in DRB1 or DQB1 allelic frequencies or CTLA-4 polymorphisms between patients and controls. However, we found that the frequency of DRB3 was significantly increased in the patients (75.5% vs. 57.4%, P = 0.006, X2 = 3.52), especially for the DRB3*0202 subtype (53.1% vs. 23.4, P = 0.003, X2 = 8.91). In this one respect, the finding was in concordance with our previous observations in Caucasian patients with adult-onset Graves' disease. In addition, whereas the frequency of DQA1*0501 was increased (P = 0.018, X2 = 5.63) in our patients, the haplotype of DRB3/DQA1*0501, or DRB3*0202/DQA1*0501 was found to be more strongly associated (P = 0.008, X2 = 7.0; P = 0.0008, X2 = 11.34, respectively). These data suggest that DRB3*0202, particularly when found with DQA1*0501 in a haplotype is a susceptible gene(s) for Graves' disease in adult African Americans. Considering these data with those in Caucasian patients, our results would suggest that the primary Graves susceptible locus is likely DRB3 and not DRB1.

Current cases in which epitope mimicry is considered as a component cause of autoimmune disease: immune-mediated (type 1) diabetes

Autoimmune diseases result from a combination of genetic, immunologic, hormonal, and environmental factors. Infectious agents may induce the breakdown of immunological tolerance and the appearance of autoreactivity. However, the specific relationship between infection and autoimmunity is still unclear. One of the mechanisms responsible could be molecular mimicry between the infectious agent and self. The concept of molecular mimicry is a viable hypothesis in the investigation of the etiology, pathogenesis, treatment, and prevention of autoimmune disorders. Immune-mediated (type 1) diabetes in humans and in non-obese diabetic (NOD) mice is polygenic and characterized by autoimmune destruction of insulin-producing pancreatic beta cells in islets of Langerhans. In NOD mice, a T-helper 1 (Th1)-based autoimmune response arises spontaneously against glutamate decarboxylase (GAD) concurrently with the onset of insulitis. Subsequently. this Th1-type autoreactivity spreads intra- and intermolecularly to other beta cell autoantigens, suggesting that a Th1-type response is responsible for the progression of the disease, whereas Th2 responses when experimentally induced are protective. In humans, a homology between GAD and the P2-C protein of Coxsackie B make a cause-and-effect molecular mimicry an attractive hypothesis. Evidence to support the concept of molecular mimicry in diabetes is reviewed.

Autoimmunity and diabetes

The face of immune-mediated (type 1) diabetes is changing. No longer considered a disease confined to childhood, the incidence rate in Western countries is clearly rising and affecting younger children. Such a secular trend can only be explained on the basis of increased contacts with adverse environmental factors acting on a background of complex genetics. Multiple defects in immunological tolerance to "self' predispose to immune-mediated (type 1) diabetes. Initiation of immune responses involves the cytokine rich natural killer T cells. Such cells appear deficient in both humans and the rodent models of the disease. Furthermore, the regulatory abilities of T cells in general seem to be compromised. Effector mechanisms probably are dominated by cell-mediated beta cell destruction through apoptosis induction. Surprisingly, the essential antigen-presenting cells in the autoimmune processes involved appear to be B lymphocytes. The improved understanding of the beta cell autoantigens involved has led to better disease prediction. The long prodromal phase now readily identifiable through autoantibodies is spawning hopes of disease prevention, notably through antigen-based interventions or diabetes "vaccines."

Protective effects of equine herpesvirus-1 (EHV-1) glycoprotein B in a murine model of EHV-1-induced abortion

In an attempt to determine if pregnant mice could be protected from abortion subsequent to challenge with equine herpesvirus-1 (EHV-1) in the mouse model of EHV-1 disease, female BALB/c mice were inoculated with baculovirus-expressed EHV-1 glycoprotein B (bac-gB), wild-type baculovirus (bac-wt), rabbit kidney (RK-13) or baby hamster kidney (BHK-21) cells. Using an ELISA, antibodies against EHV-1 were detected in the serum of mice following two injections of bac-gB and were enhanced by a third injection, after which low levels of neutralising antibody were also detected. After mating, mice in the bac-gB, bac-wt and RK-immunised groups were infected intranasally with 10(7) pfu of EHV-1 on day 16 of pregnancy. All challenged mice experienced body weight loss post-infection (pi). However, postnatally, the gB-immunised group demonstrated body weight gain which was not seen in the other groups. There were no maternal deaths in the gB-immunised group but 1/6 bac-wt-immunised and 3/6 RK-immunised mice died post-challenge. Litter survival rate was significantly higher (p < 0.001) for the gB-immunised dams (54%) than that of either the bac-wt-(9%) or RK-immunised (0%) dams and the mean body weight of young from the surviving bac-wt-immunised litter was significantly (p = 0.021) lower than either the gB-immunised group or the BHK-immunised unchallenged group at 10 days of age. The virus was not isolated from any foetus from a gB-immunised dam. However, the virus was detected in 9% of foetuses from bac-wt-immunised and 21% of foetuses from RK-immunised dams.

Study of the protective immunity of co-expressed glycoprotein H and L of equine herpesvirus-1 in a murine intranasal infection model

Equine herpesvirus-1 (EHV-1) glycoproteins H, and L (gH and gL) expressed individually or co-expressed by recombinant baculoviruses were used to immunise BALB/c mice prior to intranasal challenge in a murine model of respiratory infection. Only the co-expressed material (EHV-1 gH/gL) induced neutralising antibody (low levels). The same immunogen also produced the strongest cellular responses. Immunisation with gH/gL and, to a lesser extent, with gH alone was associated with a reduction of virus load in nasal turbinates and olfactory bulbs after challenge infection. Viraemia, detected by polymerase chain reaction, was also reduced. No such protective effects were observed for gL alone. Adoptive transfer of lymphocytes from gH/gL-immunised mice to näive mice subsequently challenged with EHV-1 indicated that both CD4+ and CD8+ cells had a role in protective immunity. Although clearance of EHV-1 from respiratory tissue was not as effective as previously found for glycoproteins D or C, these experiments provide evidence that the co-expression of EHV-1 gL with gH generates a conformational neutralising epitope which is not present in either molecule alone, and suggests that gH/gL antigen may have a better potential as a component of an EHV-1 vaccine than gH alone.

The pathogenesis of ED71, a defined deletion mutant of equine herpesvirus-1, in a murine intranasal infection model for equine abortion

A series of mutants of equine herpesvirus-1 (EHV-1) which contain deletions in non-essential genes was previously characterized in a murine intranasal infection model. One mutant, ED71 which was shown to be attenuated in the model, was further characterized by inoculation into pregnant mice. Despite the attenuation previously reported, intranasal inoculation of pregnant mice resulted in premature parturition and the birth of dead or dying foetuses. Furthermore, mice inoculated before pregnancy with the same mutant, and subsequently challenged 14 days after conception with wild-type virus, were not protected from abortion.