Merozoite surface protein-9 of Plasmodium vivax and related simian malaria parasites is orthologous to p101/ABRA of P. falciparum

Plasmodium vivax merozoite surface protein-9 (Pvmsp-9) is characterized here along with orthologues from the related simian malarias Plasmodium cynomolgi and Plasmodium knowlesi. We show that although the corresponding MSP-9 proteins do not have acidic-basic repeated amino acid (aa) motifs, they are related to the Plasmodium falciparum acidic-basic repeat antigen (ABRA) also known as p101. Recognition of this new interspecies Plasmodium MSP family stems from the prior identification of related MSP termed PvMSP-185, PcyMSP-150, and PkMSP-110 on the surface of P. vivax, P. cynomolgi and P. knowlesi merozoites. A clone containing the nearly complete P. knowlesi gene encoding PkMSP-110/MSP-9 provided a hybridization probe and initial sequence information for the design of primers to obtain the P. vivax and P. cynomolgi orthologues using polymerase chain reaction (PCR) amplification strategies. The P. vivax, P. cynomolgi and P. knowlesi msp-9 genes encode proteins that range in calculated molecular mass from 80 to 107 kDa, have typical eukaryotic signal peptides and diverse repeated motifs present immediately upstream of their termination codon. Another feature conserved among these proteins, including the P. falciparum ABRA protein, is the positions of four cysteine residues near the N-terminus, suggesting this conservation maintains structural and perhaps functional characteristics in the MSP-9 family. Rabbit polyclonal antisera raised against recombinantly expressed N-termini of P. knowlesi and P. vivax MSP-9 cross-react with the counterpart proteins in immunofluorescence and immunoblot assays. Comparative interspecies investigations of the potential role(s) of Plasmodium MSP-9 in merozoite invasion of erythrocytes and as a malaria vaccine candidate can now be pursued.     

Evaluation of classical complement pathway activation in rheumatoid arthritis: Measurement of C1q–C4 complexes as novel activation products

Objective

Novel activation products that are stable and minimally susceptible to in vitro artefacts have recently been described in the classical complement pathway. The present study assessed circulating levels of these products, i.e., covalent complexes between the recognition molecule of the classical pathway (C1q) and activated C4, in plasma samples from patients with rheumatoid arthritis (RA) to establish the relationship between these levels and the clinical and immunologic parameters in these patients.

Methods

C1q–C4 levels were measured in plasma samples from 41 patients with active RA and 43 patients with inactive RA. These levels were related to other complement activation products and to disease activity according to the Disease Activity Score in 28 joints (DAS28), using Spearman's rank correlations.

Results

C1q–C4 plasma levels were significantly higher in patients with active RA as compared with patients with RA in clinical remission (median 3.3 arbitrary units [AU], range 0.4–13.4 versus 1.7 AU, range 0.2–5.5; P = 0.0001), suggesting that activation of the classical complement pathway reflects disease activity. This was supported by a significant correlation between C1q–C4 levels and the DAS28 (r = 0.398, P = 0.0002). Levels of other complement activation products, such as activated C4 (C4b/c), were also significantly elevated in patients with active disease compared with patients with inactive disease (P = 0.03), and were correlated with C1q–C4 levels (r = 0.329, P = 0.002). Levels of C1q–C4 complexes were higher in synovial fluid samples than in plasma samples from the 4 patients tested.

Conclusion

Systemic complement activation via the classical pathway in patients with RA correlates with disease activity. These results indicate that C1q–C4 complexes may be used as a biomarker for RA.

     

Seminal plasma reduces the effectiveness of topical polyanionic microbicides

The objective of this study was to test the activity of microbicides against herpes simplex virus type 2 (HSV-2) introduced in seminal plasma. We found that seminal plasma interfered with the activity of PRO 2000 and of cellulose sulfate, increasing by 100-fold the concentration of drug required to inhibit 90% of viral plaque formation. Seminal plasma competitively inhibited binding of the microbicides to the HSV-2 envelope. Most of the interference was found in a high molecular-weight fraction; tandem mass spectrometry identified the proteins as fibronectin-1 and lactoferrin. In a murine model, the interference translated in vivo into a loss in protection. We found that 2% PRO 2000 gel protected 100% of mice challenged intravaginally with HSV-2 introduced in PBS, whereas only 55% of mice were protected if virus was introduced in seminal plasma (P=.0007, log rank test). If these findings are reflective of what occurs in humans, modifications to microbicides to ensure that they retain activity in the presence of seminal plasma are indicated.     

Inflammatory cell phenotyping of the pulmonary interstitium in idiopathic interstitial pneumonia

BACKGROUND: Several studies have implicated the role of inflammation in the pathogenesis of lung damage in idiopathic interstitial pneumonias (IIPs). Investigations of inflammatory cells in IIP have show that eosinophils, neutrophils and T cells may be associated with a poorer prognosis. OBJECTIVES: The aim of our study was to map, by quantitative analysis, the number of inflammatory cells in the lung tissue of patients with non-specific interstitial pneumonia/non-specific interstitial pneumonia (NSIP/NSIP), acute interstitial pneumonia/diffuse alveolar damage (AIP/DAD) and idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) and to correlate them with lung function tests and survival. METHODS: After immunohistochemical staining, we quantified the content of inflammatory cells [macrophages, neutrophils (elastase+), plasma cells, and CD3, CD4 and CD8 T lymphocytes (TLs)] in 20 NSIP, 20 DAD and 20 UIP surgical lung biopsies. RESULTS: The total density of inflammatory cells was significantly increased in DAD and NSIP when compared to UIP (p = 0.04). TLs were increased in DAD and NSIP when compared to UlP lungs (p < 0.05). The density of inflammatory cells in UIP showed significant differences in normal, intervening and dense fibrosis areas (p < 0.05). The most numerous cells infiltrating the mural fibrosis and honeycombing areas were plasma cells, neutrophils (elastase+), CD20+, CD3+, CD4+ and CD8+ (p < 0.05). In UIP, CD3+ TLs were directly correlated with forced expiratory volume in 1 s/forced vital capacity ratio x 100 (p = 0.05). CD68+ cells presented a significant positive correlation with the forced expiratory volume in 1 s (p = 0.04); neutrophil (elastase+) cells significantly correlated with residual volume (p = 0.02), residual volume/total lung capacity (p = 0.04) and carbon monoxide transfer factor (p = 0.03). The most important predictor of survival in UIP was CD3+ TLs (p = 0.05). CONCLUSION: The total density of inflammatory cells and lymphocytes presents a different distribution within the pulmonary parenchyma in AIP/DAD, NSIP/NSIP and IPF/UIP evolutionary adapted responses to injury. There is a localized distribution of inflammation in the normal, intervening and dense fibrosis areas of UIP for CD3+, associated with a lethal deterioration of the pulmonary function and poor survival. Our findings provide further evidence of the importance of inflammation in the pathophysiology of IIPs.     

Types of anemia and mortality among older disabled women living in the community: the Women's Health and Aging Study I

AIMS: To classify the different types of anemia among moderately to severely disabled women living in the community and examine the relationship between types of anemia and mortality. METHODS: We studied anemia in 688 women, >or=65 years, in the Women's Health and Aging Study I, a population based study of moderately to severely disabled older women living in the community in Baltimore, Maryland. Anemia was defined by World Health Organization criteria. Causes of anemia were classified as due to nutritional deficiencies (iron, folate, and B12 deficiencies), anemia of chronic inflammation, anemia with renal disease, and unexplained anemia. RESULTS: 147 of 688 (21.4%) women were anemic (hemoglobin <12 g/dL). Of the 147 anemic women, 22 (15.0%) had anemia due to nutritional causes, 45 (30.6%) had anemia due to chronic inflammation, 29 (19.7%) had anemia and renal disease, and 51 (34.7%) had unexplained anemia. The proportions of those who died over five years among non-anemic women and women with anemia due to nutritional causes, chronic inflammation, renal disease, and unexplained anemia were 26.1%, 18.2%, 38.6%, 64.3%, and 33.3%, respectively (p<0.0001). Compared with non-anemic women, those with anemia and renal disease (HR 1.99, 95% CI 1.18-3.35, p=0.009) and anemia of chronic inflammation (HR 1.69, 95% CI 1.00-2.84, p=0.05) had higher risk of death. CONCLUSIONS: Anemia is common among moderately to severely disabled older women living in the community, and about one-third of the anemia is unexplained. Anemia with renal disease and anemia of chronic inflammation are associated with a higher mortality.