HPLC-Based Purification and Isolation of Potent Anti-HIV and Latency Reversing Daphnane Diterpenes from the Medicinal Plant Gnidia sericocephala (Thymelaeaceae)

Despite the success of combination antiretroviral therapy (cART), HIV persists in low- and middle-income countries (LMIC) due to emerging drug resistance and insufficient drug accessibility. Furthermore, cART does not target latently-infected CD4+ T cells, which represent a major barrier to HIV eradication. The “shock and kill” therapeutic approach aims to reactivate provirus expression in latently-infected cells in the presence of cART and target virus-expressing cells for elimination. An attractive therapeutic prototype in LMICs would therefore be capable of simultaneously inhibiting viral replication and inducing latency reversal. Here we report that Gnidia sericocephala, which is used by traditional health practitioners in South Africa for HIV/AIDS management to supplement cART, contains at least four daphnane-type compounds (yuanhuacine A (1), yuanhuacine as part of a mixture (2), yuanhuajine (3), and gniditrin (4)) that inhibit viral replication and/or reverse HIV latency. For example, 1 and 2 inhibit HIV replication in peripheral blood mononuclear cells (PBMC) by >80% at 0.08 µg/mL, while 1 further inhibits a subtype C virus in PBMC with a half-maximal effective concentration (EC50) of 0.03 µM without cytotoxicity. Both 1 and 2 also reverse HIV latency in vitro consistent with protein kinase C activation but at 16.7-fold lower concentrations than the control prostratin. Both 1 and 2 also reverse latency in primary CD4+ T cells from cART-suppressed donors with HIV similar to prostratin but at 6.7-fold lower concentrations. These results highlight G. sericocephala and components 1 and 2 as anti-HIV agents for improving cART efficacy and supporting HIV cure efforts in resource-limited regions.

Ansellone J, a Potent in Vitro and ex Vivo HIV-1 Latency Reversal Agent Isolated from a Phorbas sp. Marine Sponge

Five new minor sesterterpenoids, ansellones H (4), I (5), J (6), and K (7) and phorone C (8), have been isolated from a Phorbas sp. marine sponge collected in British Columbia. Their structures have been elucidated by detailed analysis of NMR and MS data. Ansellone J (6) and phorone C (8) are potent in vitro HIV-1 latency reversal agents that are more potent than the reference compound and control protein kinase C activator prostratin (3). The most potent Phorbas sesterterpenoid, ansellone J (6), was evaluated for HIV latency reversal in a primary cell context using CD4+ T cells obtained directly from four combination antiretroviral therapy-suppressed donors with HIV. To a first approximation, ansellone J (6) induced HIV latency reversal at levels similar to prostratin (3) ex vivo, but at a 10-fold lower concentration.

Impact of clinicopathological parameters on survival after multiorgan resection among patients with T4 gastric carcinoma: a systematic review and meta-analysis

BACKGROUND

The prognostic factors which can improve the overall survival (OS) of patients with T4 gastric carcinoma (GC) are still controversial: a meta-analysis was conducted to analyze the impact of clinicopathological parameters on survival after MOR among patients with T4 GC.

METHODS

A systematic search was performed. Odd risks (ORs) of patients with T4 GC were used to calculate the relationship between clinicopathological parameters and OS.

RESULTS

Nine studies involving 941 patients with T4 GC were identified. Well-moderate differentiation led to increased 1-, 3-, 5-year OS with an OR of 2.63, 1.58 and 1.45. Borrmann type I-II led to increased 1-, 3-year OS with an OR of 1.67 and 2.08. No lymph node metastasis led to increased 1-, 3-, 5-year OS with an OR of 7.16, 3.18 and 3.71. Total gastrectomy led to increased 1-, 3-year OS with an OR of 2.01 and 1.79. ≥2 Organs resected led to increased 1-, 3-year OS with an OR of 2.19 and 2.19. TNM stage II-III led to increased 1-, 3-year OS with an OR of 3.68 and 5.75. Curative resection led to increased 1-, 3-, 5-year OS with an OR of 4.46, 5.80 and 5.98.

CONCLUSION

Well-moderate differentiation, Borrmann type I-II, no lymph node metastasis, total gastrectomy, ≥2 organs resected, TNM stage II-III and curative resection were positive prognostic factors for OS of patients with T4 GC.

High-level expression of B7-H1 molecules by dendritic cells suppresses the function of activated T cells and desensitizes allergen-primed animals

A body of evidence indicates that expression of the programmed cell death 1 (PD-1) receptor by activated T cells plays an important role in the down-regulation of immune responses; however, the functions of its known ligands, B7-H1 (PD-L1) and B7-dendritic cell (DC; PD-L2), at the effector phase of immune responses are less clear. In the current study, we investigated the roles of B7-H1 in DC-mediated regulation of hapten-activated T cells and the delayed-type contact hypersensitivity response in primed animals. We found that the expression of B7-H1 and B7-DC was induced on activation of DC by hapten stimulation. Blockade of B7-H1, but not B7-DC, enhanced the activity of hapten-specific T cells. Interaction with a DC line that expresses high cell-surface levels of B7-H1 (B7-H1/DC) suppressed the proliferation of, and cytokine production by, activated T cells. In vivo administration of hapten-carrying B7-H1/DC desensitized the response of sensitized animals to hapten challenge, and this desensitization was hapten-specific. These data indicate that B7-H1 expressed by DC mediates inhibitory signals for activated T cells and suppresses the elicitation of immune responses. The ability of B7-H1/DC to inhibit the function of preactivated T cells in vivo suggests novel strategies for the treatment of immune response-mediated disorders.

Neuronal repellent Slit2 inhibits dendritic cell migration and the development of immune responses

One of the essential functions of dendritic cells is to take up Ags in peripheral tissues and migrate into secondary lymphoid organs to present Ags to lymphocytes for the induction of immune responses. Although many studies have demonstrated that the migration of dendritic cells is closely associated with the development of immune responses, little is known about factors that inhibit dendritic cell migration and control the extent of immune responses to Ag stimulation. We show that Slit2, a neuronal repellent factor, is up-regulated in the skin by allergen sensitization and down-regulates the migration of Langerhans cells. The effect is mediated by direct interaction of Slit2 with cells that express a Slit-specific receptor, Robo1. Slit2-mediated inhibition of Langerhans cell migration results in suppression of contact hypersensitivity responses. These findings provide insights into a novel mechanism by which Slit2 functions as an anti-inflammatory factor for the initiation of immune responses.

GammadeltaT cells regulate the development of hapten-specific CD8+ effector T cells in contact hypersensitivity responses

It has been reported that gammadeltaT cells are required for transfer of contact hypersensitivity responses by hapten-primed T cells. The mechanism by which they do so, however, remains to be elucidated. To specifically investigate the role of gammadeltaT cells in the development of contact hypersensitivity, this study employed Tdelta gene knockout mice that are deficient in gammadeltaT cells but are normal in the development of alphabetaT cells. The result indicates that contact hypersensitivity responses were significantly greater in gammadeltaT cell deficient mice than in wild-type mice. Similar results were obtained when wild-type mice were depleted of gammadeltaT cells with antibody treatment before hapten sensitization. Depletion of CD4+ T cells did not affect the increased contact hypersensitivity response in gammadeltaT cell deficient mice, suggesting that the effect of gammadeltaT cells is on CD8+ T cells and does not require CD4+ T cells. Further experiments demonstrated that primed CD8+ T cells from the deficient mice exhibited significantly higher CTL activity. The cytokine profile of CD4+ T cells was not significantly altered. Transfer of primed lymph node cells from hapten-primed gammadeltaT cell deficient mice elicited a similar level of contact hypersensitivity in naive wild-type and the deficient recipient mice, indicating that gammadeltaT cells have little effect on the elicitation of primed T cells and contact hypersensitivity responses. We conclude that gammadeltaT cells downregulate contact hypersensitivity responses to hapten sensitization by limiting the development of hapten-specific CD8+ effector T cells during sensitization and that this effect is independent of CD4+ T cells.

The role of ICAM-1 molecule in the migration of Langerhans cells in the skin and regional lymph node

ICAM-1 (CD54) plays an important role in the cell-cell interaction and migration of leukocytes. Previous studies have shown that ICAM-1 is involved in inflammatory reactions and that a defect in ICAM-1 gene inhibits allergic contact hypersensitivity. This study indicates that the migration of hapten presenting Langerhans cells into the regional lymph nodes was significantly reduced in ICAM-1-deficient mice compared to wild-type C57BL/6 mice. The reduced number of dendritic cells in regional lymph nodes did not result from abnormal migration of Langerhans cells into the skin of ICAM-1-deficient mice. The concentration and distribution of Langerhans cells in the naïve skin of ICAM-1-deficient mice was equal to that of wild-type mice. Following hapten sensitization, Langerhans cell migration out of the skin and recruitment of fresh Langerhans cells back to the epidermis was not affected in ICAM-1-deficient mice. Further experiments demonstrated that ICAM-1 deficiency on lymphatic endothelium rather than on dendritic cells was responsible for the reduced migration of Langerhans cells into draining lymph nodes. This study indicates that ICAM-1 regulates the migration of dendritic cells into regional lymph nodes but not into or out of the skin.

[The diagnosis and treatment of intracranial tuberculoma]

OBJECTIVE

To improve the level of diagnosis and treatment of intracranial tuberculoma.

METHODS

Fourteen intracranial tuberculoma cases were hospitalized in the past five years, accounting for 0.9 per cent of the intracranial tumors in the same period. Five out of fourteen cases were treated conservatively while other nine were treated surgically. All the cases were received 6-month short-course anti-tuberculosis chemotherapy, among which only one case's treatment was prolonged to one year.

RESULT

All the cases had good outcome, none of them dead.

CONCLUSIONS

Operative indications of intracranial tuberculoma cases should be applied strictly. Good result could be gained via a short-course anti-tuberculosis chemotherapy, no matter operation was performed or not.