Tips from the journals of the American Society for Microbiology

08/17/04

New Vaccine May Protect Against Cervical Cancer

Researchers from Maryland have developed a new DNA vaccine that targets proteins expressed in cervical cancer cells. Their findings appear in the August 2004 issue of the Journal of Virology.

Human papillomavirus (HPV) is found in more than 99 % of cervical cancer cases, which is the second leading cause of cancer death among women throughout the world. Consistently identified in HPV cancer cells, proteins E6 and E7 are the determined cause of malignant transformation.

In the study mice were immunized with a DNA vaccine encoding CRT (a binding protein with many cellular functions) and linked to E6 targeting HPV-associated lesions. Results showed a significant T-cell immune response specific to E6, indicating that a CRT/E6 DNA vaccine could also protect against E6 expressing tumors.

"We have shown that DNA vaccines encoding E6 can generate strong E6-specific CD8+ T-cell immunity and can control the growth of E6-expressing tumor cells," say the researchers. "Therefore, E6 vaccines, and perhaps E6 and E7 vaccines in combination, may represent an important approach to controlling HPV-associated cancers."

(S. Peng, H. Ji, C. Trimble, L. He, Y. Tsai, J. Yeatermeyer, D.A.K. Boyd, C. Hung, T.-C. Wu. 2004. Development of a DNA vaccine targeting human papillomavirus type 16 oncoprotein E6. Journal of Virology, 78. 16: 8468-8476.)


New Antimalarial Compound Identified Through Self-Medicative Behavior of Wild Chimps

French and Ugandan researchers have discovered novel antimalarial compounds by observing the behavior of wild chimps. Their findings appear in the August 2004 issue of the journal Antimicrobial Agents and Chemotherapy.

In the study researchers observed a Kanyawara community of fifty wild chimpanzees for unusual feeding behaviors, especially those of ill chimps. Stool and urine samples were collected for analysis. The occasional ingestion of Trichilia rubescens by the chimps was noted as unusual, as only one chimp per group would feed on the shrub for a short period of time often leaving before finishing, with the leftovers remaining untouched by any other group member. Crude extracts from the plant leaves of T. rubescens showed significant antimalarial activity, suggesting that chimps eating the T. rubescens leaves may have a temporary variation in food choice despite symptomatic conclusions drawn by health monitoring.

"New evidence has been provided to support the previous hypothesis that chimpanzee diet contains secondary metabolites that may be useful to health maintenance," say the researchers. "The study of self-medication in apes based in veterinary and behavioral survey might provide a novel approach to the discovery of new bioactive natural products useful in human therapy."

(S. Krief, M. Martin, P. Grellier, J. Kasenene, T. Sevenet. 2004. Novel antimalarial compounds isolated in a survey of self-medicative behavior of wild chimpanzees in Uganda. Antimicrobial Agents and Chemotherapy, 48. 8: 3196-3199.)


Genetics May Determine Gum Disease in Humans

Genetics may determine susceptibility or resistance to the bacteria that causes periodontal disease in humans say researchers from Maine and Missouri. Their findings appear in the August 2004 issue of the journal Infection and Immunity.

Periodontal disease, the most prevalent chronic inflammatory disease in humans, is an infection in the gums that results in destruction of tooth-supporting tissue and bone, ultimately causing tooth loss. Bacteria accumulate along the gum line initiating an immune response.

"Gingival immune responses have been associated with the pathogenesis, severity, and genetic susceptibility to human periodontal disease," say the researchers.

In the study researchers compared gene expression in the gingiva and spleens of two mouse strains, testing the susceptibility of one group and the resistance of the other, before and after oral infection with Porphyromonas gingivalis. Following infection, spleen and gingival gene expression indicating susceptibility (genes Il1b, Tnf, and Stat6) increased in the susceptible group only while gene expression indicating resistance (genes Il15 and Selp) in the second group also increased.

"These results suggest a molecular phenotype in which discrete sets of differentially expressed genes are associated with genetically determined susceptibility (Il1b, Tnf, and Stat6) or resistance (Il15 and Selp) to alveolar bone loss, providing insight into the genetic etiology of this complex disease," say the researchers.

(G.T. Hart, D.J. Shaffer, S. Akilesh, A.C. Brown, L. Moran, D.C. Roopenian, P.J. Baker. 2004. Quantitative gene expression profiling implicates genes for susceptibility and resistance to alveolar bone loss. Infection and Immunity, 72. 8: 4471-4479.)

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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