Cl Lin

Activation of Th1 Immunity Is a Common Immune Mechanism for the Successful Treatment of Hepatitis B and C: Tetramer Assay and Therapeutic Implications

Both chronic hepatitis B and C virus (HBV and HCV) infections respond ineffectively to current antiviral therapies. Recent studies have suggested that treatment outcomes may depend on the development of type 1 T helper (Th1) and Th2 cell responses. Specifically, activation of Th1 immunity may play a major role in successfully treating hepatitis B and C. This model was revisited herein by evaluating immune responses in 36 HBV and 40 HCV patients with or without treatment, in an attempt to find a common immune mechanism for successful treatment. The immune responses in all examined cases were studied by peripheral blood mononuclear cell (PBMC) proliferation and cytokine responses to viral antigens, cytotoxic T lymphocyte (CTL) responses, enzyme-linked immunospot (ELISPOT) assay, and tetramer staining of virus-specific CD8+ T cells. The overall results revealed that all responders among both HBV- and HCV-infected cases displayed significantly higher PBMC proliferation to viral antigens with a predominant Th1 cytokine profile. Furthermore, the Th1-dominant responses were associated with significant enhancement of CTL activities and were correlated with ELISPOT data, while non-responders responded more weakly. During therapy, the numbers of tetramer-staining, virus-specific CD8+ T cells showed greater increases in responders than in non-responders (p = 0.001). The frequencies determined by the tetramer assay were approximately 200-fold higher than data estimated by limiting-dilution analysis. In conclusion, activation of Th1 immunity accompanied by enhancement of CTL activity during therapy is a common immune mechanism for successfully treating hepatitis B and C, and therefore may have important therapeutic implications.

Earlier appearance and higher incidence of the rectoanal relaxation reflex in patients with imperforate anus repaired with laparoscopically assisted anorectoplasty

Background: This study aimed to evaluate clinically and manometrically the anorectal function of patients with imperforate anus after repair with laparoscopically assisted anorectoplasty (LAR), as compared with the function of patients after undergoing the conventional method, posterior sagittal anorectoplasty (PSARP). Methods: The defecation status and anorectal manometry of patients with high or intermediate type imperforate anus repaired with LAR (n = 9) and age-matched patients repaired with PSARP (n = 13) were assessed and compared during the first year of postoperative follow-up evaluation. The defecation status was classified by the frequency of bowel openings (<1, 1–4, and >5 times per day). Manometric assessment was performed by an open-tip hydraulic capillary infusion system. The presence of the rectoanal relaxation reflex was determined, and the resting sphincteric pressure and resting rectal pressure were measured. Results: Seven of nine LAR patients had an “acceptable” frequency of one to four bowel openings per day, in contrast to 7 of 13 PSARP patients. The difference in the presentation of daily stooling is not significant (p > 0.05). A positive RAR was detected in 88.9% (8/9) of the LAR patients, and in only 30.8% (4/13) of the PSARP patients (p < 0.01). The presence of a rectoanal relaxation reflex also significantly correlated with an acceptable frequency of bowel opening (1–4 times per day) in both LAR and PSARP patients (p < 0.05). Moreover, a rectoanal relaxation reflex was detected significantly earlier in LAR than in PSARP patients (4.9 ± 1.2 vs 10.1 ± 2.5 months; postoperatively p < 0.0001). Both the LAR and PSARP patients had a similar resting sphincteric pressure (21.5 ± 4.7 vs 25.4 ± 6.2 cm H2O; p > 0.05). By contrast, the resting rectal pressure was significantly lower in LAR than in PSARP patients (7.7 ± 1.5 vs 11.5 ± 1.3 cmH2O; p < 0.05). Conclusions: In the early postoperative stage, patients repaired with LAR had more favorable findings in anorectal manometry than patients repaired with PSARP. Long-term follow-up studies to confirm a superior defecation continence achieved with LAR are warranted.

Conjugation of latent membrane protein (LMP)-2 epitope to gold nanoparticles as highly immunogenic multiple antigenic peptides for induction of Epstein-Barr virus specific cytotoxic T-lymphocyte responses in vitro?

Nasopharyngeal carcinoma is a neoplasm with a high incidence in Southeast Asia, and it is strongly associated with Epstein-Barr virus (EBV) activation involving the expression of a weakly immunogenic protein, namely, latent membrane protein (LMP)-2. Previous immunological studies already identified the human leukocyte antigen (HLA)-A11 restricted peptide epitope (SSCSSCPLSK) in the LMP-2 antigen. In this work, we prepared gold nanoparticle (AuNP)-peptide conjugate 1 by treating the nanoparticles with the N-cysteinated LMP-2 epitope. The AuNP-peptide conjugates have been characterized by TEM (15-24 nm in diameter) and UV-vis spectroscopy (surface plasmon resonance absorption band at lambda(max) = 520 nm). In the presence of a CALNN capping peptide, the AuNP-peptide conjugates are stable in solution without aggregation at room temperature for at least 48 h. By ELIspot studies, AuNP-peptide conjugate 1 was found to elicit a significantly stronger INF-gamma response [number of spot forming cells (SPC) = 727 +/- 198] from peripheral blood mononuclear cells of healthy HLA-A11 donors when compared to that induced by the unconjugated LMP-2 peptides (SFC = 73 +/- 28). Further studies showed that dendritic cells treated with conjugate 1 can effect CD8+ T-cell activation leading to epitope-specific cytotoxic T lymphocyte killing responses in vitro.