Comparative transcriptomics in Syllidae (Annelida) indicates that posterior regeneration and regular growth are comparable, while anterior regeneration is a distinct process

Background

Annelids exhibit remarkable postembryonic developmental abilities. Most annelids grow during their whole life by adding segments through the action of a segment addition zone (SAZ) located in front of the pygidium. In addition, they show an outstanding ability to regenerate their bodies. Experimental evidence and field observations show that many annelids are able to regenerate their posterior bodies, while anterior regeneration is often limited or absent. Syllidae, for instance, usually show high abilities of posterior regeneration, although anterior regeneration varies across species. Some syllids are able to partially restore the anterior end, while others regenerate all lost anterior body after bisection. Here, we used comparative transcriptomics to detect changes in the gene expression profiles during anterior regeneration, posterior regeneration and regular growth of two syllid species: Sphaerosyllis hystrix and Syllis gracilis; which exhibit limited and complete anterior regeneration, respectively.

Results

We detected a high number of genes with differential expression: 4771 genes in S. hystrix (limited anterior regeneration) and 1997 genes in S. gracilis (complete anterior regeneration). For both species, the comparative transcriptomic analysis showed that gene expression during posterior regeneration and regular growth was very similar, whereas anterior regeneration was characterized by up-regulation of several genes. Among the up-regulated genes, we identified putative homologs of regeneration-related genes associated to cellular proliferation, nervous system development, establishment of body axis, and stem-cellness; such as rup and JNK (in S. hystrix); and glutamine synthetase, elav, slit, Hox genes, β-catenin and PL10 (in S. gracilis).

Conclusions

Posterior regeneration and regular growth show no significant differences in gene expression in the herein investigated syllids. However, anterior regeneration is associated with a clear change in terms of gene expression in both species. Our comparative transcriptomic analysis was able to detect differential expression of some regeneration-related genes, suggesting that syllids share some features of the regenerative mechanisms already known for other annelids and invertebrates.

Polyclad phylogeny persists to be problematic

Two conflicting morphological approaches to polyclad systematics highlight the relevance of molecular data for resolving the interrelationships of Polycladida. In the present study, phylogenetic trees were reconstructed based on a short alignment of the 28S rDNA marker gene with 118 polyclad terminals (24 new) including 100 different polyclad species from 44 genera and 22 families, as well as on a combined dataset using 18S and 28S rDNA genes with 27 polyclad terminals (19 new) covering 26 different polyclad species. In both approaches, Theamatidae and Cestoplanidae were included, two families that have previously been shown to switch from Acotylea to Cotylea. Three different alignment methods were used, both with and without alignment curation by Gblocks, and all alignments were subjected to Bayesian inference and maximum likelihood tree calculations. Over all trees of the combined dataset, an extended majority-rule consensus tree had weak support for Theamatidae and Cestoplanidae as acotyleans, and also the cotylean genera Boninia, Chromyella and Pericelis appeared as acotyleans. With the most inclusive short 28S dataset, on the other hand, there is good support for the aforementioned taxa as cotyleans. Especially with the short 28S matrix, taxon sampling, outgroup selection, alignment method and curation, as well as model choice were all decisive for tree topology. Well-supported parts of the phylogeny over all trees include Pseudocerotoidea, Prosthiostomoidea, Stylochoidea, Leptoplanoidea and Cryptoceloidea, the latter three with new definitions. Unstable positions in the tree were found not only for Theamatidae, Cestoplanidae, Boninia, Chromyella and Pericelis, but also for Anonymus, Chromoplana and Cycloporus.

Effectiveness of an oral cholera vaccine in Zanzibar: findings from a mass vaccination campaign and observational cohort study

BACKGROUND

Zanzibar, in east Africa, has been severely and repeatedly affected by cholera since 1978. We assessed the effectiveness of oral cholera vaccination in high-risk populations in the archipelago to estimate the indirect (herd) protection conferred by the vaccine and direct vaccine effectiveness.

METHODS

We offered two doses of a killed whole-cell B-subunit cholera vaccine to individuals aged 2 years and older in six rural and urban sites. To estimate vaccine direct protection, we compared the incidence of cholera between recipients and non-recipients using generalised estimating equations with the log link function while controlling for potential confounding variables. To estimate indirect effects, we used a geographic information systems approach and assessed the association between neighbourhood-level vaccine coverage and the risk for cholera in the non-vaccinated residents of that neighbourhood, after controlling for potential confounding variables. This study is registered with ClinicalTrials.gov, number NCT00709410.

FINDINGS

Of 48,178 individuals eligible to receive the vaccine, 23,921 (50%) received two doses. Between February, 2009, and May, 2010, there was an outbreak of cholera, enabling us to assess vaccine effectiveness. The vaccine conferred 79% (95% CI 47-92) direct protection against cholera in participants who received two doses. Indirect (herd) protection was shown by a decrease in the risk for cholera of non-vaccinated residents within a household's neighbourhood as the vaccine coverage in that neighbourhood increased.

INTERPRETATION

Our findings suggest that the oral cholera vaccine offers both direct and indirect (herd) protection in a sub-Saharan African setting. Mass oral cholera immunisation campaigns have the potential to provide not only protection for vaccinated individuals but also for the unvaccinated members of the community and should be strongly considered for wider use. Because this is an internationally-licensed vaccine, we could not undertake a randomised placebo-controlled trial, but the absence of vaccine effectiveness against non-cholera diarrhoea indicates that the noted protection against cholera could not be explained by bias.

FUNDING

Bill & Melinda Gates Foundation, Swedish International Development Cooperation Agency, and the South Korean Government.

Safety of the recombinant cholera toxin B subunit, killed whole-cell (rBS-WC) oral cholera vaccine in pregnancy

Introduction

Mass vaccinations are a main strategy in the deployment of oral cholera vaccines. Campaigns avoid giving vaccine to pregnant women because of the absence of safety data of the killed whole-cell oral cholera (rBS-WC) vaccine. Balancing this concern is the known higher risk of cholera and of complications of pregnancy should cholera occur in these women, as well as the lack of expected adverse events from a killed oral bacterial vaccine.

Methodology/Principal Findings

From January to February 2009, a mass rBS-WC vaccination campaign of persons over two years of age was conducted in an urban and a rural area (population 51,151) in Zanzibar. Pregnant women were advised not to participate in the campaign. More than nine months after the last dose of the vaccine was administered, we visited all women between 15 and 50 years of age living in the study area. The outcome of pregnancies that were inadvertently exposed to at least one oral cholera vaccine dose and those that were not exposed was evaluated. 13,736 (94%) of the target women in the study site were interviewed. 1,151 (79%) of the 1,453 deliveries in 2009 occurred during the period when foetal exposure to the vaccine could have occurred. 955 (83%) out of these 1,151 mothers had not been vaccinated; the remaining 196 (17%) mothers had received at least one dose of the oral cholera vaccine. There were no statistically significant differences in the odds ratios for birth outcomes among the exposed and unexposed pregnancies.

Conclusions/Significance

We found no statistically significant evidence of a harmful effect of gestational exposure to the rBS-WC vaccine. These findings, along with the absence of a rational basis for expecting a risk from this killed oral bacterial vaccine, are reassuring but the study had insufficient power to detect infrequent events.

Trial Registration

ClinicalTrials.gov NCT00709410

Pregnant women are more vulnerable to complications of cholera than other people. It would be helpful to include pregnant women in vaccination campaigns against cholera but pregnant women and their unborn children are highly vulnerable to the potential adverse effects of biological products such as vaccines. The safety of oral cholera vaccines in pregnant women has up to now not been evaluated. During a large mass cholera vaccination campaign in Zanzibar in 2009, women were advised not to participate if they thought they may be pregnant. The large majority (955 or 83%) of women residing in the study area who were to be pregnant during the 9 months following the vaccinations did not participate in the campaign. The remaining 196 (17%) women received the vaccine. A comparison between vaccine exposed and unexposed pregnancies did not reveal any significant differences in outcome between the two groups. The small number of miscarriages, infant deaths and ill infants was similarly distributed between the two groups. These findings are reassuring but continued monitoring of this vaccine when given during pregnancy is recommended.

Review of the symbiotic genus Haplosyllides (Polychaeta: Syllidae), with a description of a new species

The genus Haplosyllides was considered as monotypic, with H. floridana as the only valid species. The present revision Includes two more species in this genus: H. aberrans comb. nov. and H. ophiocomae sp. nov. Syllis (Haplosyllis) aberrans (from Vietnam) was considered a Junior synonym of H. floridana (from the Caribbean). The finding of additional specimens from Vietnam and Indonesia, and the study of the type series, allowed us to redescribe H. aberrans comb. nov. on the basis of morphological, ecological and biogeographical characteristics. Haplosyllides aberrans comb. nov. differs from H. floridana in having posterior simple chaetae with tips twice as long, a pharyngeal tooth in all non-reproductive Individuals, and the granules Inside the dorsal cirri oval, elongated, and roughly distributed in longitudinal parallel rows. Haplosyllides ophiocomae sp. nov. was previously reported (as H. aberrans) from Puerto Rico. Although geographically close, It differs from H. floridana in having serration on the upper edge of the major teeth of simple chaetae, relatively shorter dorsal cirri, and a distinct mode of life. Haplosyllides floridana lives as an endosimbiont of Xetospongia muta, H. aberrans comb. nov. as a facultative parasite of Platycaris latirostris, and H. ophiocomae sp. nov. as a commensal of Ophiocoma pumila and other brittle stars. The meaning of these associations is discussed in light of the available Information. The remaining records of "Haplosyllides aberrans" from the Marshall Islands (associated with corals of the genus Heliopora) and from Brazil (among corals and calcareous algae) are considered as doubtful.

Technologies to improve immunisation safety

Ever since a vaccine was first used against smallpox, adverse events following immunisation have been reported. Adverse reactions may be caused by a fault in vaccine production, idiosyncratic responses or unsafe handling and vaccine administration practices. Technological advances that promise to bypass many of the dangers currently associated with vaccine administration are described. Plans for the next decade and beyond include developing injection-free systems for vaccine delivery that overcome the limitations of current immunisation programmes and help prevent programmatic mistakes. Also under development are new parenteral administration devices such as the auto-disable syringe and the mono-dose pre-filled device, and mucosal and transcutaneous immunisation systems. Training needs to be at the forefront of efforts to limit human error. Above all, there must be a willingness to respond to new climates and new technologies in order to ensure safe immunisation of children globally.

Ensuring vaccine safety in immunization programmes--a WHO perspective

Ever since vaccines were firstly used against smallpox, adverse events following immunization have been reported. As immunization programmes expand to reach even the most remote communities in the poorest countries, it is likely that many more events will be temporally linked with vaccine administration. Furthermore, the profound shift in the general public and media interest in adverse events may lead to undue concerns and allegations which may ultimately jeopardize immunization programmes world-wide. While the health professional has understood this issue for some time, the public and the media have now also become all too aware of the significance of vaccine-related adverse events. The familiar vaccines, well-tested over decades, have not changed--but the perception regarding their safety has shifted. Claims outrageous or reasonable are being made against both the old and the newly-introduced vaccines. At the same time, the immunological and genetic revolution of the last decade may well bring to our notice some hypothetical risks that need to be addressed at pre-clinical level. WHO has been at the leading edge to guarantee vaccine safety for the last 30 years and will continue to do so. The Organization's plans for the next decade and beyond include the Safe Injection Global Network (SIGN), the development and introduction of safer technologies, and the prevention, early detection and management of AEFIs. The new technologies include needle-containing injection devices such as the autodisable syringe, as well as mucosal and transcutaneous immunization. Training will continue to be at the centre of WHO's efforts, limiting human error to a minimum. Mechanisms have been set in place to detect and respond to new and unforeseen events occurring. Above all, there is a willingness to respond to new climates and new technologies so that the Organization is in the best position to ensure safe immunization for all the world's children.

Recombinant bacillus Calmette-Guérin as a potential vector for preventive HIV type 1 vaccines

In August 1997, the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) convened an expert working group to discuss current strategies for the development of HIV type 1 vaccines. Based on the recent findings of investigators from Japan's National Institute of Infectious Diseases (NIID) in Tokyo using recombinant bacillus Calmette-Guérin (rBCG) as a potential vectored vaccine for HIV, a recommendation was made that further work in this area is a priority. As a result, the working group reconvened in September 1998 to discuss the progress to date with this vaccine approach, as well as areas of related research to assess the feasibility of a BCG-vectored HIV vaccine. This report summarizes the discussions addressing the available scientific data on the potential use of rBCG as a vector for preventive HIV vaccines, the work necessary to move such candidate vaccines into Phase 1 clinical trials, and recommendations targeted at facilitating the long-term development of rBCG-vectored HIV vaccines.

Future approaches to vaccine development: single-dose vaccines using controlled-release delivery systems

The development of single-dose vaccines, mainly those administered during childhood, which would effectively protect against certain diseases, would be a very important advance towards better immunization coverage and protection against the respective pathogens. Biodegradable polymeric microspheres which are 'programmed' to deliver the antigen when a boost of the immune response is required, may be a possible way of achieving this goal.

Towards vaccine optimisation

New molecular technologies have accelerated the search for sub-unit candidate vaccines. However, once identified the use of a candidate antigen must be optimised to reap the maximum benefit from the eventual vaccine. This optimisation should take into account both the needs of the target population, and the various ways of potentiating the protective immune response induced. One must be sure that the final product will be used. Hence, vaccine optimisation should strive toward meeting the needs of a specific epidemiological problem within the economic constraints of a given situation. This may be possible using novel delivery systems designed to limit the number of doses needed, improve the stability or facilitate the delivery of a particular vaccine. In meeting the needs of a target population in a field situation, one must also keep in mind certain safety factors that go beyond the usual regulatory constraints. The immune response to vaccine candidates can be potentiated in many ways. The ability to preferentially induce specific protective effector mechanisms: i.e., antibody isotypes, T-cell subsets, and T-cell sub-subsets, is becoming a reality. Carrier molecules designed to avoid the problems of epitope suppression and competition, and perhaps an eventual "carrier jam," are being developed. Adjuvants and immunostimulants may also help, but the critical issue here remains their acceptability for use in man. Finally novel strategies for the induction of the immune response may also potentiate the immune response in the optimisation of vaccines.

Human lung cancer--a comparative study of the levels of circulating immune complexes in pulmonary blood draining the tumor area and peripheral venous blood

Our objective was to investigate whether low levels of circulating immune complexes (cICs) in peripheral venous blood of cancer patients could be due to removal of cIC released at the tumor site during passage to the peripheral veins. In 54 patients with primary lung cancer, we therefore compared the cIC levels as detected by 3 different assays in paired samples from the pulmonary vein draining the tumor area and from a peripheral vein. Only 6 of the 54 patients had significantly increased pulmonary vein cIC levels as compared to the corresponding peripheral vein levels. The peripheral vein levels of these 6 patients were all within the normal range, and in none of these patients was the difference between the 2 sites of analysis--although significant--of such a magnitude that the pulmonary vein cIC level appeared higher than the normal range, i.e., "positive" for cIC. Positive cIC levels were only found in 11% of lung cancer patients (irrespective of the site of measurement). Thus, our present data, together with our previous findings indicating no significant difference between peripheral venous blood cIC levels in cancer patients and normal controls, contradict the theory of tumor cells expressing new antigens resulting in the formation of tumor-associated cICs.

Genetic diversity of murine rheumatoid factors

Anti-Ig autoantibodies (rheumatoid factors, RF) have been implicated in the pathogenesis of human and murine rheumatoid arthritis as well as in the regulation of normal immune responses. Their genetic origin, clonal diversity, and inducing agents, and the relatedness between RF associated with disease and those occurring under physiologic conditions are not well understood. In this study, the genetic and clonotypic origin of 34 monoclonal IgM RF-secreting hybridomas from arthritic MRL-lpr/lpr and nonarthritic MRL-+/+ and C57BL/6-lpr/lpr mice was examined by RNA hybridization. For this purpose, we used probes for 10 VH and 13 Vk gene families as well as all JH and Jk gene segments. The majority of hybridomas expressed distinct Ig gene segment patterns and, hence, were clonally unrelated. Overall, a variety of different V and J gene segments were expressed in the hybridoma panel, suggesting that a large number of distinct genetic elements participates in expression of RF-like activity. RF from arthritic mice expressed Vk messages from the overlapping Vk22 and Vk28 gene families more frequently than did those from nonarthritic mice. RF from autoimmune MRL mice, both arthritic MRL-lpr/lpr and nonarthritic MRL-+/+, showed skewed JH4 segment usage, whereas those from C57BL/6-lpr/lpr preferentially expressed JH2.

Genetic diversity of murine rheumatoid factors

Anti-Ig autoantibodies (rheumatoid factors, RF) have been implicated in the pathogenesis of human and murine rheumatoid arthritis as well as in the regulation of normal immune responses. Their genetic origin, clonal diversity, and inducing agents, and the relatedness between RF associated with disease and those occurring under physiologic conditions are not well understood. In this study, the genetic and clonotypic origin of 34 monoclonal IgM RF-secreting hybridomas from arthritic MRL-lpr/lpr and nonarthritic MRL-+/+ and C57BL/6-lpr/lpr mice was examined by RNA hybridization. For this purpose, we used probes for 10 VH and 13 Vk gene families as well as all JH and Jk gene segments. The majority of hybridomas expressed distinct Ig gene segment patterns and, hence, were clonally unrelated. Overall, a variety of different V and J gene segments were expressed in the hybridoma panel, suggesting that a large number of distinct genetic elements participates in expression of RF-like activity. RF from arthritic mice expressed Vk messages from the overlapping Vk22 and Vk28 gene families more frequently than did those from nonarthritic mice. RF from autoimmune MRL mice, both arthritic MRL-lpr/lpr and nonarthritic MRL-+/+, showed skewed JH4 segment usage, whereas those from C57BL/6-lpr/lpr preferentially expressed JH2.

Primary lung cancer. A controlled study of preoperative and postoperative levels of circulating immune complexes

Three complement-dependent and one rheumatoid factor-dependent immune complex assays were used to analyze the sera taken before surgery from 70 unselected and previously untreated lung cancer patients, from 30 of them after surgery, and from 31 healthy controls. Plasma levels of complement split product C3d were also analyzed. The levels of circulating immune complexes (cIC) and C3d were essentially the same in samples taken from lung cancer patients before surgery and from healthy controls. By the four immune complex assays, increased levels were found in 0 to 10% of the preoperative lung cancer patients compared to 3% of the healthy controls (not significant). The postsurgical tumor, lymph node, metastasis (pTNM) stage of the lung cancer was not reflected in the levels of cIC or C3d. Paired comparisons of the cIC and C3d levels before and after surgery did not show significant differences. Thus, we found no evidence for the occurrence of cancer-related cIC in lung cancer patients.

A prospective study of circulating immune complexes in patients with breast cancer

Levels of circulating immune complex (cIC) and complement split product C3d were studied in 86 patients with breast cancer (BC), 22 patients with benign breast disease (BD), and 72 age- and sex-matched blood-bank donors (NC), using solid-phase Clq-protein A RIA, Clq-anti-IgG RIA, anti-C3d anti-IgG RIA, and polyclonal IgM-rheumatoid factor ELISA for clC detection. No significant differences in cIC and C3d levels were found between the groups. The incidence of raised cIC levels varied from 4.9 to 8.2% in the BC group and from 4.5 to 22.7% in the BD group in comparison with 2.9 to 3.0% in the NC group. Using the solid-phase polyclonal IgM-rheumatoid factor ELISA we found that the cIC levels of patients with stage-III cancer were significantly higher than those of patients with stage-I or stage-II cancer. However, the other tests showed no relationship to tumor burden. Likewise, an effect of mastectomy on the cIC levels was also only detectable by one of the assays, i.e., the post-mastectomy levels of cIC as measured by the solid-phase anti-C3d anti-IgG RIA were significantly lower than the pre-mastectomy levels. Serial analyses of cIC and C3d levels were performed pre-operatively, one month post-operatively and every 3 months during the first year after mastectomy in 46 of the patients. During a I-year observation period, 7 patients developed metastatic disease. The occurrence of metastatic disease was not, however, preceded by characteristic changes in serially determined cIC and C3d levels.

Prognostic value of serial determinations of circulating immune complex levels in malignant melanoma

A total of 50 melanoma patients free of distant metastatic disease and 54 healthy controls were analyzed for circulating immune complexes (cIC) and complement split product (C3d), using solid-phase Clq-anti-IgG radioimmunoassay (RIA), Clq-protein A RIA, and anti-C3d anti-IgG RIA for cIC detection. No significant differences in cIC and C3d levels could be demonstrated between the controls and the 31 patients with primary malignant melanoma analyzed before surgery. To evaluate the prognostic value of serial measurements, samples from the 50 patients were taken at regular intervals for 4 to 27 months (median, 20 months). Surgery was the only treatment given. Significant changes in the cIC and C3d levels were defined by reference to the changes that occurred in 23 of the 54 healthy controls observed for a period of 6 to 55 months (median, 23 months). During the period of serial sampling, recurrent disease developed in 8 of the patients. In only 3 of these 8 patients (versus 10 of 42 patients without recurrence) did significant changes occur, and the changes occurred either at the same time or after the clinical diagnosis of recurrence. During the entire clinical observation period of 6 years, a total of 11 patients developed recurrences. Significant changes were only observed in 4 of these 11 patients versus 8 of 37 patients without recurrence. In conclusion, changes in cIC and/or C3d levels were not found to be indicative of early or long-term recurrence of malignant melanoma.

The genetic origin of murine lupus-associated autoantibodies

Systemic lupus erythematosus and rheumatoid arthritis in human and murine systems are characterized by circulating autoantibodies and immune complex deposition in various organs causing tissue damage and disease. To define the molecular and clonotypic origin of these anti-self responses, and to determine whether abnormalities in Ig genes or somatic mechanisms generating autoantibody diversity may contribute to lupus etiology, we performed molecular analyses of the Ig germline gene organization and the Ig gene segments expressed in monoclonal autoantibodies from autoimmune mice. Comparative restriction fragment length polymorphism analysis of a large number of Ig gene loci from autoimmune and normal mice indicated that (a) lupus can develop in different Ig heavy and kappa light chain variable region gene haplotypes, and (b) the Ig germline genes in lupus mice might be normal. To determine whether autoantibodies are encoded by unique Ig gene segments present in the normal germline repertoire, but not expressed in exogenous responses, we compared nucleic acid sequences encoding lupus autoantibodies and antibodies against foreign antigens. Similar, and in some instances even identical, gene segments were expressed in both types of antibodies, indicating that anti-self and anti-foreign responses use the same, or at least an overlapping, germline gene repertoire. A large variety of Ig variable, diversity, and joining gene segments encoded these autoantibodies with different specificities. Hence, the overall murine lupus-associated anti-self response may be essentially unrestricted. Furthermore, limited evidence has been obtained that both germline genes and somatically mutated genes encode autospecificity, making gross abnormalities in mechanisms for somatic mutation of Ig variable genes unlikely.(ABSTRACT TRUNCATED AT 250 WORDS)

Specificity and molecular characteristics of monoclonal IgM rheumatoid factors from arthritic and non-arthritic mice

Two-hundred twenty-four hybridomas secreting monoclonal IgM rheumatoid factor (hIgMRF) derived from MRL-lpr/lpr, MRL-+/+ and C57BL/6-lpr/lpr autoimmune mice were analyzed with regard to IgG subclass and domain specificity, and some for VH gene expression patterns. Among these mice, only MRL-lpr/lpr develop arthritis. Clonotypes specific for each of the four mouse IgG subclasses and clonotypes reacting with more than one IgG subclass were identified. Although each panel contained several clonotypes, the predominant one differed in each strain (MRL-lpr/lpr, anti-IgG2a; MRL-+/+, combined anti-IgG2a and 2b; C57BL/6-lpr/lpr, anti-IgG1 or combined anti-IgG1, 2a, and 3). The IgG domains recognized by these monoclonals were defined with mutant Ig carrying IgG1 heavy chains that lacked either the CH1 or CH3 domains, variant Ig carrying hybrid IgG2b-2a heavy chains, and IgG fragments. Inhibition of hIgMRF binding to IgG substrates by protein A was also assessed. Most determinants were assigned to the CH3 domain, but determinants in the hinge region, CH2 domain, and in some instances, even in the Fab portion, could also be identified. Hybridization of cytoplasmic RNA from 35 classes of diverse IgG subclass specificity with VH gene probes representing seven of the approximately 10 VH families (7183, S107, Q52, J558, J606, 36-60, X24) indicated that approximately 90% of these clones expressed VH genes belonging to the large J558 gene family. The results indicate that murine IgMRF are extremely heterogeneous in IgG subclass and domain specificities; the genetic background influences RF specificity characteristics that may relate to pathogenicity; and considering the complexity of the J558 VH gene family and reported RF heavy chain assignments to additional VH gene families, it appears that VH genes encoding RF are diverse.

Specificity and molecular characteristics of monoclonal IgM rheumatoid factors from arthritic and non-arthritic mice

Two-hundred twenty-four hybridomas secreting monoclonal IgM rheumatoid factor (hIgMRF) derived from MRL-lpr/lpr, MRL-+/+ and C57BL/6-lpr/lpr autoimmune mice were analyzed with regard to IgG subclass and domain specificity, and some for VH gene expression patterns. Among these mice, only MRL-lpr/lpr develop arthritis. Clonotypes specific for each of the four mouse IgG subclasses and clonotypes reacting with more than one IgG subclass were identified. Although each panel contained several clonotypes, the predominant one differed in each strain (MRL-lpr/lpr, anti-IgG2a; MRL-+/+, combined anti-IgG2a and 2b; C57BL/6-lpr/lpr, anti-IgG1 or combined anti-IgG1, 2a, and 3). The IgG domains recognized by these monoclonals were defined with mutant Ig carrying IgG1 heavy chains that lacked either the CH1 or CH3 domains, variant Ig carrying hybrid IgG2b-2a heavy chains, and IgG fragments. Inhibition of hIgMRF binding to IgG substrates by protein A was also assessed. Most determinants were assigned to the CH3 domain, but determinants in the hinge region, CH2 domain, and in some instances, even in the Fab portion, could also be identified. Hybridization of cytoplasmic RNA from 35 classes of diverse IgG subclass specificity with VH gene probes representing seven of the approximately 10 VH families (7183, S107, Q52, J558, J606, 36-60, X24) indicated that approximately 90% of these clones expressed VH genes belonging to the large J558 gene family. The results indicate that murine IgMRF are extremely heterogeneous in IgG subclass and domain specificities; the genetic background influences RF specificity characteristics that may relate to pathogenicity; and considering the complexity of the J558 VH gene family and reported RF heavy chain assignments to additional VH gene families, it appears that VH genes encoding RF are diverse.

Clearance kinetics and organ uptake of complement-solubilized immune complexes in mice

C3-bearing immune complexes were prepared by in vitro solubilization of BSA-anti-BSA complexes at equivalence. Sucrose density gradient analyses showed a size-heterogeneous population of solubilized complexes with a range of 7S to greater than 29S and a peak at around 19S. The presence of C3bi was demonstrated by precipitation with antibodies to C3c and to C3d and by binding to conglutinin. Immune complexes solubilized in two and three times antigen excess were selected as controls due to their size similarities with complement-solubilized complexes. Blood clearance curves were very similar for C3-bearing complexes and controls. At 1 hr, the percentage of injected material remaining in the circulation for complement-solubilized and two and three times antigen excess complexes were 29.5 +/- 1.3, 30.9 +/- 1.7 and 26.1 +/- 2.7, respectively. Uptake by liver accounted for the majority of complement- and antigen-solubilized immune complexes removed from circulation. Although the uptake by the spleen was no more than one-tenth of the liver uptake, more complement-solubilized complexes than antigen-solubilized complexes were removed by this organ. The present data indicate that soluble immune complexes bearing C3 components and soluble immune complexes without C3 components, but of comparable size, are cleared from the circulation of mice at comparable rates. The mechanisms of clearance of these two populations of complexes, however, may differ.

Monoclonal antibodies against complement 3 neoantigens for detection of immune complexes and complement activation. Relationship between immune complex levels, state of C3, and numbers of receptors for C3b

C3-bearing immune complexes and C3 activation products were detected by using two monoclonal antibodies, one specific for a neoantigenic determinant on C3c and the other for C3d. To quantitate immune complexes, the anti-C3c or anti-C3d antibodies were fixed to microtiter plates and reacted with test plasma. The binding of C3-bearing immune complexes in this plasma was then measured with radioisotope- or enzyme-labeled anti-human IgG. To test for C3 breakdown products, solid-phase monoclonal antibody to the C3d neoantigen was reacted with EDTA-plasma samples, and fixed iC3b or C3d was measured with a polyclonal anti-C3 antibody. Patients with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and Sjogren's syndrome, and paracoccidioidomycosis were found to contain immune complexes bearing C3b/iC3b or C3d. In most conditions, there were more C3d-containing immune complexes than C3b/iC3b. Although CR1 (C3b receptors) rapidly converted immune complex-bound iC3b to C3dg/C3d and lupus patients had reduced CR1, no correlation between the state of C3 on circulating immune complexes or levels of immune complexes and CR1 numbers was seen. However, levels of C3-fixing ICs correlated with levels of C3 activation products. This assay system with monoclonal antibodies to neoantigens expressed on activated, but not native, C3 provides sensitive and specific means for detecting and classifying C3-fixing immune complexes and for assessing C3 activation.

Association of lpr gene with graft-vs.-host disease-like syndrome

Hemopoietic cells have been reciprocally transferred between two lines of mice (MRL lpr/lpr and MRL +/+) that are congenic, differing only at the lpr (lymphoproliferation) and possibly closely linked genes. The lpr strain develops a significantly more severe and fast-paced lupus-like syndrome than +/+ strain, along with a substantially larger lymphoid mass. The results showed that: (a) hemopoietic cells of such mice were sufficient to induce the respective disease phenotypes in lethally irradiated syngeneic recipients; (b) cells of MRL +/+ mice maturing in an MRL lpr/lpr environment essentially retained the disease-producing characteristics of the donor, i.e., they induced late-life lupus without lymphadenopathy; but (c) MRL lpr/lpr cells transferred into irradiated MRL +/+ recipients unexpectedly failed to induce the early-life severe lupus and lymphoid hyperplasia of the donor, instead they caused a severe wasting syndrome resembling, in many respects, graft-vs.-host disease (GVHD). This GVHD-like syndrome developed after transfer of MRL lpr/lpr fetal liver, bone marrow, or spleen cells, and was not abrogated by elimination of T cells from the inocula. Thymectomy of the MRL +/+ recipients retarded, but did not prevent, the wasting disease. The unidirectional nature of this disease suggests that the lpr mutation conferred either a structural or regulatory defect that interfered, blocked, or altered the expression or structure of certain lymphocyte antigen(s). As a result, the MRL +/+ cells that did express this antigen(s) were recognized as foreign, and stimulated a graft-vs.-host reaction. These findings may allow definition of a new kind of rejection phenomenon caused by non-H-2 products, and may extend our understanding of the means by which the lpr gene adversely affects lymphocyte regulation and homeostasis.

Induction of severe autoimmune disease in normal mice by simultaneous action of multiple immunostimulators

Either of two immunostimulating factors (lpr, lipopolysaccharide) enhanced the pathogenic autoimmune responses of MRL/n mice, but the serologic and immunopathologic characteristics differed. In contrast, either factor acting alone, caused minimal immunopathology in normal mice, despite autoantibody induction. Combined immunostimulation, however, caused fatal glomerulonephritis in normal-background C57BL/6 mice. These results show the profound influence of the background genome on the effects of immunostimulating agents, and show that resistance to autoimmune disease in immunologically normal mice is not absolute.

Frequency and clinical and transfusional significance of rheumatoid factor in patients with haemophilia and von Willebrand's disease

Using a solid-phase radioimmunoassay for IgM rheumatoid factor, increased levels were found in 24% or 82 patients with haemophilia A, in 4 of 11 patients with haemophilia B, in 2 of 11 patients with haemophilia A with inhibitors and in 4 of 12 with von Willebrand's disease. The levels of rheumatoid factor increased significantly (p less than 0.02) after factor VIII concentrate or cryoprecipitate transfusions. No clinical or transfusional side effects could be attributed in these patients in relation to the presence of rheumatoid factor.

Effect of circulating immune complexes on transfusional therapy in patients with hemophilia or von Willebrand's disease

Circulating immune complexes were examined in patients with hemophilia or von Willebrand's disease in order to determine the immediate or long-term side effects after transfusion. The conglutinin binding assay which allows quantitation of C3bi-bearing immune complexes was used for 82 patients with hemophilia A. Immune complexes were detected in 37 (45%) of these cases prior to transfusion. Immune complexes also were detected in four of 11 patients with hemophilia A and factor VIII inhibitors, in five of 11 patients with hemophilia B, and in three of 10 patients with von Willebrand's disease. The levels of circulating immune complexes in 21 patients with hemophilia A and seven with von Willebrand's disease significantly increased 24 hours after concentrate or cryoprecipitate transfusions. Purified immune complexes from three patients with hemophilia A were shown to contain IgG, IgM, and complement components. No factor VIII coagulant or antigenic protein or fibrinogen was identified in the immune complexes using specific antisera. Side effects immediately after transfusion were not associated with immune complexes. The levels of factor VIII or IX after transfusion were not particularly decreased in relation to the presence of immune complexes. Finally, the presence of circulating immune complexes in the patients studied did not correlate with the number of transfusions, the units of concentrates injected, the presence of HBsAg or HbsAb, the levels of plasma aspartate transferase, or the presence of rheumatoid factor. Proteinuria was absent in all the patients studied.

Capacity to solubilize immune complexes in sera and synovial fluids from patients with rheumatoid arthritis

Fifty-six sera and 33 synovial fluids from rheumatoid arthritis patients were studied to evaluate their capacity to solubilize immune complexes. A decreased function was found in 65% of rheumatoid synovial fluids when compared with 13 osteoarthritis synovial fluids. The decrease of immune complex solubilization capacity correlated with the decrease of hemolytic activity of the alternative complement pathway (P less than 0.001) and inversely with the level of immune complexes (P less than 0.05). Synovial fluids with low and normal immune complex solubilization capacity were compared; the results confirmed a possible role of the synovial complement system in modulating the size and thus the diffusion and clearance of locally generated immune complexes.

[Activation of the alternative complement pathway in pleural fluid of patients with pneumonia]

It has been reported that the opsonic activity of pleural fluid is decreased in patients with pneumonia complicated by infected effusions (empyema) compared to those with sterile (metapneumonic) effusions. In this paper some parameters of complement activity in 12 patients with empyema and in 13 patients with metapneumonic effusions were compared. The hemolytic activity of the alternative pathway and of Factor B in empyemas (15 +/- 10% and 25+15%, respectively) was less than that measured in metapneumonic effusions (55 +/- 38% and 71 +/- 21%; p less than 0.01). Both parameters showed a significant correlation (r=0.76; p less than 0.01). The Ba fragment, a catabolic product of Factor B, was increased in empyema (125 +/- 59%) compared to that in metapneumonic effusions (49 +/- 24%; p less than 0.01). The levels of C3, protein of both, alternative and classical pathways, were decreased in empyema (17 +/- 29%) when compared with the levels in metapneumonic pleural effusion (42 +/- 20%; p less than 0.01). The levels of this protein were correlated with the activity of alternative complement pathway (r=0.68; p less than 0.01), as well as with those of Factor B (r=0.75; p less than 0.01). Finally, the hemolytic activity of C4, as a representative element of the classical pathway, has also shown to be decreased in empyema (6 +/- 6%) compared to metapneumonic fluids (27 +/- 28%; p less than 0.01). Significant correlations between the hemolytic activity of C4 and levels of C3 (r=0.75; p less than 0.01), the hemolytic activity of the alternative pathway (r=0.63; p less than 0.01) and the levels of Factor B (r=0.73; p less than 0.01) were demonstrated. This last suggest a simultaneous activation of both, classical and alternative pathways of complement. The complement decrease and particularly, the activation of the alternative pathway in patients with empyema could be a determinant factor of the deficient bacterial opsonization. This can explain the survival of bacteria in an empyema despite the large number of neutrophils present.

Decreased capacity to solubilize immune complexes in sera from patients with systemic lupus erythematosus

The capacity to solubilize immune complexes formed in vitro is significantly decreased in patients with systemic lupus erythematosus (SLE). This complement function correlates significantly with serum C3 levels and inversely with the presence of circulating immune complexes. Clinically, patients with a decreased capacity, to solubilize complexes show a worse evolution and an increased incidence of renal involvement. In conclusion, the impaired solubilization capacity, related to low complement activity, which is observed in patients with SLE may favor the persistence of immune complexes in tissues.

Evaluation of alternative pathway and factor B haemolytic activities in patients with systemic lupus erythematosus: correlations with the alternative pathway regulatory proteins

The haemolytic activities of the complement alternative pathway and factor B were studied using a 51Cr-release assay in 77 sera from patients with systemic lupus erythematosus (SLE). These values were compared to those of several complement components and of the regulatory proteins beta H and C3b INA. There was a significant decrease in the alternative pathway activity, which correlated with a decrease in the haemolytic activity of factor B and with the activity of the classical pathway. There was a significant decrease in the level of one regulatory protein beta 1H, while the level of the other regulatory protein, C3b INA, was increased; however, there was a positive correlation between these two parameters. The results obtained suggest that the decreased activity of the alternative pathway observed in SLE reflects a consumption due to a triggering of the C3b amplification loop through the activation of the classical pathway. In one patient, an acquired deficiency of the capacity to activate the alternative pathway in the presence of inulin was observed.

Demonstration of a local exhaustion of complement components and of an enzymatic degradation of immunoglobulins in pleural empyema: a possible factor favouring the persistence of local bacterial infections

Local bacterial infections such as abscesses or purulent exudates most often contain numerous, easily culturable bacteria despite an intense inflammatory reaction characterized by the ingress of polymorphonuclear leucocytes. In order to understand the mechanisms leading to such a persistent infection, we used pleural empyema as a model and measured the levels and catabolism of complement as well as of immunoglobulins in 28 infectious pleural effusions associated with either a positive or with a negative bacterial culture. Classic and alternative pathway haemolytic activities, factor B and C4 haemolytic activities as well as native C3 were markedly decreased or undetectable in most culture-positive effusions when compared to culture-negative effusions (P less than 0.005); breakdown products of factor B and C3 were markedly increased in culture-positive fluids. Eleven out of 14 culture-positive fluids exhibited IgG breakdown as opposed to none of the culture-negative fluids. In seven out of 14 culture-positive fluids, incubation with 125I-IgG led to their in vitro breakdown. This proteolytic activity could be abolished by preincubation of the culture-positive fluids with normal sera. Thus, increased catabolism of complement and breakdown of immunoglobulins, both leading to local consumption of immune reactants, could be one of the causes for bacterial persistence in pleural empyema.

Separation of granulocytes from peripheral blood in a single step using discontinuous density gradients of Ficoll-Urografin. A comparative study with separation by dextran

A single-step method for separating granulocytes from peripheral blood using two different gradients of Ficoll-Urografin (F-U) density 1.075 and 1.097 g/ml) is described. The morphological, cytochemical and ultrastructural properties of neutrophils isolated by this method were compared to those isolated by dextran-enhanced sedimentation and neutrophils from the peripheral blood. These studies indicated fewer alterations in neutrophils separated by F-U centrifugation than in neutrophils concentrated by dextran. Finally, the granulocyte layer recovered by F-U fractionation was 98% pure (dextran 71%) and yielded 64% (dextran 79%) of total granulocytes.