Autoantibodies against Cajal bodies in systemic lupus erythematosus

BACKGROUND

Cajal bodies (CB) are distinct sub-nuclear domains rich in small nuclear ribonucleoprotein particles (snRNPs); they are involved in pre-mRNA processing. Lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody production against different nuclear molecules, including those involved in pre-mRNA processing. The aim of the present investigation is to assess the presence of anti-CB autoantibodies in a cohort of SLE sera.

MATERIAL/METHODS

Antinuclear antibodies (ANA) were screened by indirect immunofluorescence in a batch of 190 sera from patients who met the ACR criteria for SLE classification; fine specificity was determined by Western blot using HEp-2 cells or rat hepatocyte extracts purified by ion exchange chromatography.

RESULTS

Four sera had anti-Cajal body (CB) autoantibodies. Interestingly, all of these patients had intermittent extensive oral and esophageal ulceration. The autoantibodies to CB were of the IgG class, and by Western blot these sera had reactivity against an 80 kDa protein (coilin) associated with Sm proteins.

CONCLUSIONS

Anti-CB autoantibodies constitute an uncommon specificity of SLE; therefore it seems that anti-CB antibody specificity is associated with extensive mucous ulceration.

[Toward development of a Taenia solium paramyosin-based vaccine against porcine cysticercosis]

Taenia solium paramyosin (TPmy) is a prominent 100 kDa antigen in human and porcine cysticercosis. TPmy is an alpha-helical coiled coil protein present in muscle and tegumentary structures of T. solium cysticerci. TPmy has the property of binding C1q resulting in inhibition of the complement cascade. TPmy probably binds C1q through its collagen-like domains and could be involved in a parasite strategy to modulate host immune response. Humoral immune response against TPmy is prefrentially directed against carboxyl terminal end in humans and mice, whereas amino terminal end of TPmy preferentially induces a Th1-related cellular immune response. Protection studies in murine model of cysticercosis showed that the amino terminal end fragment of TPmy induces approximately 60% protection against an i.p. challenge with Taenia crassiceps cysts when mice are immunized with recombinant fragments of TPmy. Initial protection studies using genetic immunization showed that amino terminal end fragment of TPmy cloned into a plasmid expression vector with a cytomegalovirus promoter, together with IL-12-expressing plasmids induced 79% protection, suggesting that this kind of TPmy-immunization might result in development of a cost-effective vaccine against cysticercosis.

Human T and B cell epitope mapping of Taenia solium paramyosin

Taenia solium paramyosin is an immunodominant antigen in human and porcine cysticercosis that has shown promise as a vaccine candidate against schistosomiasis and some filariasis. There are few studies to identify the immunologically relevant regions of paramyosin. In this work, we characterize the humoral and cellular response of neurocysticercotic patients against T. solium paramyosin. Western blots using different recombinant fragments of T. solium paramyosin, showed that the sera from neurocysticercotic patients were strongly reactive against the carboxyl end region, with poor recognition of the central and amino regions. In contrast, the cellular immune response of patients did not show preferential recognition of any region of paramyosin.

Characterization and protective potential of the immune response to Taenia solium paramyosin in a murine model of cysticercosis

Paramyosin has been proposed as a vaccine candidate in schistosomiasis and filariasis. However, limited information is available about its protective potential against cysticercosis and the immune response it induces. Immunization of mice with recombinant full-length paramyosin of Taenia solium (TPmy) results in about a 52% reduction in parasite burden after a subsequent challenge by intraperitoneal inoculation of Taenia crassiceps cysticerci. Immunization assays using recombinant fragments of TPmy, corresponding approximately to thirds on the amino, central, or carboxyl regions, suggest that protective epitopes are located mostly in the amino-end third. Proliferation assays using T cells obtained from mice immunized with the full-length recombinant TPmy also showed a preferential response to the amino-terminal fragment. In contrast, antibodies in the sera from these mice predominantly recognize epitopes located in the carboxyl-terminal fragment, being the immunoglobulin G1 subclass, the predominant antibody isotype. Characterization of the cellular immune response induced against the protective amino-terminal fragment reveals production of gamma interferon and interleukin-2, but not interleukin-4, suggesting a Th1-like profile.