Phenology determines seasonal variation in ectoparasite loads in a natural insect population

1. The extent to which individuals are parasitised is a function of exposure to parasites and the immune response, which in ectotherms may be associated with temperature. 2. We test the hypothesis that seasonal variation in ectoparasite burden is driven by temperature using an extensive mark‐release‐recapture study of adult Coenagrion puella (L.) (Zygoptera) as a model system. Mite counts were taken both at capture and on a subset of subsequent recaptures over two entire, consecutive breeding seasons. 3. Emergence date was the most significant factor in determining individual differences in mite burden, and mean counts for individuals emerging on the same days showed strong unimodal relationships with time of season. Subsequent recounting of mites on a subset of individuals showed that patterns of loss of mites were similar between seasons. 4. While temperature did not significantly affect mite burdens within seasons and ectoparasite prevalence was very similar across the two seasons, intensity of infection and rate of mite gain in unparasitised individuals were significantly higher in the cooler season. 5. We demonstrate that, while temperature may modulate the invertebrate immune response, this modulation does not manifest in variations in mite burdens in natural populations.     

Association of immune parameters with clinical outcome in stage III colon cancer: results of Southwest Oncology Group Protocol 9009

Levamisole (LMS), utilized in the adjuvant treatment of patients with stage III colon cancer, is immunomodulatory. To determine whether alterations in immune parameters before, during and after 12 months of 5FU/LMS therapy correlate with disease-free survival, 38 patients enrolled on Southwest Oncology Group (SWOG) protocol 8899 received extensive lymphocyte phenotypic analysis prior to therapy and 3, 6, 12 and 15 months after treatment initiation. The median follow-up of patients is 41 months. Significant increases in the proportion and total number of CD56⁺ natural killer cells were seen, starting at 3 months and continuing until 15 months (P < 0.001). Increases in the total numbers of cells expressing CD25 (interleukin-2 receptor), VLA4 and the combinations of CD4: CD45RA and CD4:CDw29 were not evident during therapy but were seen at 15 months (P < 0.05: CD25, CD4:CDw29, CD4:CD45RA; P < 0.001: VLA4). Low levels of CD8⁺ cells prior to treatment initiation and after 3 months of therapy correlated with early relapse within the first year of 5FU/LMS treatment. Patients who have remained disease-free (n = 22, median follow-up 45 months) demonstrated increases in the total numbers of CD8⁺, CD25⁺, CD56⁺, VLA4⁺, CD4: CDw29 and CD4:CD45RA cells, primarily at 15 months. In contrast, patients who relapsed had decreased numbers of CD8⁺, CD4:CDw29, CD4: CD45RA and VLA4⁺ cells and minimal increases in CD56⁺ and CD25⁺ cells. Statistically significant differences between the late-relapse group and the group remaining disease-free were seen for CD25⁺, CD4: CD45RA and CD4:CDw29 cells at the 15-month assay time (P = 0.0276, P = 0.0349, P = 0.0178 respectively). In conclusion, multiple alterations in lymphocyte phenotype, with increases in the proportion and total number of cells involved in cell-mediated immune responses, were seen during and especially following completion of therapy with 5FU/LMS. Many of these changes are significantly associated with clinical outcome and may be useful for risk stratification of stage III colon cancer patients following completion of adjuvant therapy. Received: 9 July 1999 / Accepted: 11 August 1999     

Passive hinge forces in the feeding apparatus of<Emphasis Type="Italic"> Aplysia</Emphasis> aid retraction during biting but not during swallowing

Swallowing and biting responses in the marine mollusk Aplysia are both mediated by a cyclical alternation of protraction and retraction movements of the grasping structure, the radula and underlying odontophore, within the feeding apparatus of the animal, the buccal mass. In vivo observations demonstrate that Aplysia biting is associated with strong protractions and rapid initial retractions, whereas Aplysia swallowing is associated with weaker protractions and slower initial retractions. During biting, the musculature joining the radula/odontophore to the buccal mass (termed the hinge) is stretched more than in swallowing. To test the hypothesis that stretch of the hinge might contribute to rapid retractions observed in biting, we analyzed the hinges passive properties. During biting, the hinge is stretched sufficiently to assist retraction. In contrast, during swallowing, the hinge is not stretched sufficiently for its passive forces to assist retraction, because the odontophores anterior movement is smaller than during biting. A quantitative model demonstrated that steady-state passive forces were sufficient to generate the retraction movements observed during biting. Experimental measures of the relative magnitude of the hinges active and passive forces at the protraction displacements of biting suggest that passive forces are at least a third of the total force.Abbreviations I1/I3 intrinsic buccal muscles 1 and 3 - I2 intrinsic buccal muscle 2 (nomenclature from Howells 1942)     

Role of Shiga toxin 2 (Stx2)-binding protein,human serum amyloid P component (HuSAP), in Shiga toxin-producing Escherichia coli infections: assumption from in vitro and in vivo study using HuSAP and anti-Stx2 humanized monoclonal antibody TMA-15

Shiga toxin 2 (Stx2) is a major pathogenic factor in Shiga toxin-producing Escherichia coli (STEC) infections. Some factor that neutralizes Stx2 in vitro had been shown to be specifically present in human serum and we recently identified it as human serum amyloid P component (HuSAP). Here, we report the role of HuSAP in STEC infections. HuSAP could not rescue Stx2-challenged mice from death, and it instead reduced the efficacy of the Stx2-neutralizing humanized monoclonal antibody TMA-15 when a lower dose of TMA-15 was injected to the mice. By contrast, the efficacy of TMA-15 at a higher dose was uninfluenced by the presence of HuSAP. These findings suggest that HuSAP acts as a carrier protein of Stx2 rather than as a Stx2-neutralizing factor in the human circulation and that passive immune therapy with Stx2-neutralizing antibodies such as TMA-15 is useful to prevent severe complications associated with STEC infections even in the presence of HuSAP.     

Assessment of antibody responses to antigens of Mycobacterium tuberculosis and Cysticercus cellulosae in cerebrospinal fluid of chronic meningitis patients for definitive diagnosis as TBM/NCC by passive hemagglutination and immunoblot assays

Tanned sheep erythrocytes stabilized with pyruvic aldehyde and glutaraldehyde, called double-aldehyde-stabilized cells, were used to standardize passive hemagglutination assay (PHA) for detection of antibody responses to sonicate extract of Mycobacterium tuberculosis and Cysticercus cellulosae soluble antigens. PHA was performed in the following groups of cerebrospinal fluid (CSF) samples: group I - chronic infections of the central nervous system with the possible diagnosis of tuberculous meningitis (TBM), tuberculoma and neurocysticercosis (NCC) (n=88), and group II - controls which included (a) non-infectious non-neurological conditions (n=30), (b) infectious neurological conditions (n=21) and (c) non-infectious neurological conditions (n=133). PHA could detect anti-mycobacterial antibodies at the sensitivity level of 80.76% with a specificity of 92.4% and anti-cysticercal antibodies with a sensitivity of 100% and specificity of 92.94%. However, in 6.33% (i.e. 14/221) of group I and group II (c) CSFs both anti-mycobacterial and anti-cysticercal antibodies were detected. Immunoblot analysis of CSFs derived from TBM patients reacted predominantly to 120-kDa, 96-kDa, 65-kDa, 38-kDa, 26-kDa, 23-kDa, 19-kDa and 12-14-kDa and 4-6-kDa antigens of M. tuberculosis sonicate extract (MTSE), whilst CSFs of proven NCC reacted to >110-kDa, 96-kDa, 80-kDa, 66-68-kDa, 52-kDa and 26-28-kDa antigens of porcine whole cyst sonicate extract (PCSE). On immunoblot analysis, some of the CSFs of TBM patients were PHA positive for both MTSE and PCSE showed antibody reactivity to 70-kDa and 10-kDa antigens of C. cellulosae. Similarly CSF antibody of some Guillain Barre syndrome and myeloradiculopathy patients reacted with cysticercal antigens. But per se no cross-reactivity between MTSE and anti-cysticercal antibodies and vice-versa were observed. However, findings of this study should alert laboratory personnel especially in endemic areas to be extra careful in interpretation of antibody detection results.     

Evolution of interleukin-1beta

All jawed vertebrates possess a complex immune system, which is capable of anticipatory and innate immune responses. Jawless vertebrates posses an equally complex immune system but with no evidence of an anticipatory immune response. From these findings it has been speculated that the initiation and regulation of the immune system within vertebrates will be equally complex, although very little has been done to look at the evolution of cytokine genes, despite well-known biological activities within vertebrates. In recent years, cytokines, which have been well characterised within mammals, have begun to be cloned and sequenced within non-mammalian vertebrates, with the number of cytokine sequences available from primitive vertebrates growing rapidly. The identification of cytokines, which are mammalian homologues, will give a better insight into where immune system communicators arose and may also reveal molecules, which are unique to certain organisms. Work has focussed on interleukin-1 (IL-1), a major mediator of inflammation which initiates and/or increases a wide variety of non-structural, function associated genes that are characteristically expressed during inflammation. Other than mammalian IL-1β sequences there are now full cDNA sequences and genomic organisations available from bird, amphibian, bony fish and cartilaginous fish, with many of these genes having been obtained using an homology cloning approach. This review considers how the IL-1β gene has changed through vertebrate evolution and whether its role and regulation are conserved within selected non-mammalian vertebrates.     

A novel asparaginase-like protein is a sperm autoantigen in rats

A novel asparaginase-like protein (ALP) of spermatozoa was cloned from rat and human testis cDNA libraries on the basis of reactivity with antibodies produced after vasectomy. Although obstruction of the male reproductive tract is known to cause an immunologic response, few of the sperm antigens responsible for the generation of autoantibodies have been characterized. We are identifying proteins of interest by coring autoantigenic protein spots from two-dimensional (2-D) gels of rat sperm extracts and microsequencing them by mass spectrometry. The peptide sequences from ALP, a 28 kDa, pI 5.7 protein, matched to a single partial length rat EST. These peptide sequences were used to clone a cDNA encoding a novel 333 amino acid open reading frame. The new protein had a similarity to portions of L-asparaginases of plants (43%) and to glycosylasparaginases in animal cells (32%). Human ALP cDNA was subsequently cloned. It showed 77% identity to the rat ALP sequence and the gene, ASRGL1 (asparaginase-like 1), mapped to chromosome locus 11q12.3. Purified recombinant rat ALP (rALP), expressed in E. coli, was used to raise polyclonal antiserum in guinea pigs. Two observations verified that the correct protein had been cloned: 1) the anti-rALP antibody reacted with both rALP and rat sperm; and 2) post-vasectomy sera bound rALP. Anti-rALP antibody stained the midpiece of rat and human sperm coincident with staining by MitoTracker Green FM, suggesting that ALP is associated with the mitochondria. Northern analysis revealed that rat ALP message was abundantly expressed in the testis but was also present in heart, brain, liver, skeletal muscle, and kidney.     

Identification and characterization of mouse SSX genes: a multigene family on the X chromosome with restricted cancer/testis expression

Human SSX was first identified as the gene involved in the t(X;18) translocation in synovial sarcoma. SSX is a multigene family, with 9 complete genes on chromosome Xp11. Normally expressed almost exclusively in testis, SSX mRNA is expressed in various human tumors, defining SSX as a cancer/testis antigen. We have now cloned the mouse ortholog of SSX. Mouse SSX genes can be divided into Ssxa and Ssxb subfamilies based on sequence homology. Ssxa has only one member, whereas 12 Ssxb genes, Ssxb1 to Ssxb12, were identified by cDNA cloning from mouse testis and mouse tumors. Both Ssxa and Ssxb are located on chromosome X and show tissue-restricted mRNA expression to testis among normal tissues. All putative human and mouse SSX proteins share conserved KRAB and SSX-RD domains. Mouse tumors were found to express some, but not all, Ssxb genes, similar to the SSX activation in human tumors.     

The self peptide annexin II (208–223) presented by dendritic cells sensitizes autologous CD4+ T lymphocytes to recognize melanoma cells

Annexin II is known to be over-expressed in different types of tumours. We show here that annexin II protein is expressed by melanoma cell lines in various amounts, consistent with previous findings that an annexin II (208-223) peptide could be eluted from isolated HLA-DR molecules of a constitutively MHC class II-positive melanoma line. T cells sensitized to annexin II (208-223) in vitro using peptide-pulsed autologous dendritic cells responded only to the lines which overexpressed annexin II, in a peptide-specific, HLA-DR-restricted fashion. These CD4+ T cells proliferated strongly and secreted large amounts of type 1 cytokines in response to annexin II (208-223) peptide or annexin II protein-positive melanoma cell lines. These results demonstrate that the annexin II (208-223) peptide, corresponding to a non-mutated sequence of a normal protein, induces antigen-specific T cells which can respond to melanoma cells over-expressing the annexin II molecule. This peptide may therefore be useful in immunotherapy for recruiting CD4+ type 1 helper cells active locally in the tumour environment.