Anti-interleukin-10R1 monoclonal antibody enhances bacillus Calmette-Guérin induced T-helper type 1 immune responses and antitumor immunity in a mouse orthotopic model of bladder cancer.

PURPOSE: Proper induction of the T-helper type 1 immune response is required for effective bacillus Calmette-Guérin immunotherapy for bladder cancer. Interleukin-10 down-regulates the T-helper 1 response and is associated with bacillus Calmette-Guérin failure. We investigated whether blocking interleukin-10 receptor 1 would enhance the bacillus Calmette-Guérin induced T-helper type 1 immune response and anti-bladder cancer immunity in a mouse model. MATERIALS AND METHODS: Splenocytes were incubated with bacillus Calmette-Guérin or bacillus Calmette-Guérin plus control IgG1, anti-interleukin-10 receptor 1 mAb or anti-interleukin-10 neutralizing mAb, followed by enzyme-linked immunosorbent assay of interferon-γ production. Bladder RNA was extracted after intravesical bacillus Calmette-Guérin plus intraperitoneal IgG1 or anti-interleukin-10 receptor 1 mAb and analyzed by reverse transcriptase and/or quantitative polymerase chain reaction. Urine was collected and analyzed by enzyme-linked immunosorbent assay. Mice bearing a luciferase expressing MB49 orthotopic tumor were treated with intravesical bacillus Calmette-Guérin plus intraperitoneal IgG1 or anti-interleukin-10 receptor 1 mAb. Tumor response was assessed by bioluminescent imaging and bladder weight measurement. RESULTS: Bacillus Calmette-Guérin plus anti-interleukin-10R1 mAb induced significantly higher interferon-γ production by splenocytes than bacillus Calmette-Guérin plus anti-interleukin-10 mAb. Bacillus Calmette-Guérin plus anti-interleukin-10 receptor 1 mAb also induced significantly higher interferon-γ mRNA and protein in bladder and urine, respectively, in a dose dependent manner. Treatment with phosphate buffered saline, bacillus Calmette-Guérin plus control IgG1 and bacillus Calmette-Guérin plus anti-interleukin-10 receptor 1 mAb showed a 0% tumor-free rate with a 20% death rate, a 20% tumor-free rate with a 20% death rate and a 40% tumor-free rate with a 0% death rate, respectively. Bladder weight also revealed the effect of anti-interleukin-10 receptor 1 mAb on the bacillus Calmette-Guérin induced bladder tumor response. CONCLUSIONS: Anti-interleukin-10 receptor 1 mAb enhanced the bacillus Calmette-Guérin induced T-helper type 1 immune response and anti-bladder cancer immunity. A humanized form of this mAb warrants future investigation for bacillus Calmette-Guérin treatment of bladder cancer.

Utilization of lipopolysaccharide challenge in cynomolgus macaques to assess IL-10 receptor antagonism.

The current era of drug discovery has been marked by a significant increase in the development of immune modulating agents to address a range of diseases such as cancer, chronic inflammation, and other conditions of dysregulated immunity. Non-clinical evaluation of these agents in animal models can be challenging, as the presence of an active immune state is often required in order to detect the effects of the test agent. Modulation of interleukin (IL)-10 signaling represents this type of situation in that altering IL-10 action in vivo can be difficult to appreciate in the absence of an ongoing immune response. The study presented here reports on the use of lipopolysaccharide (LPS) challenge in cynomolgus macaques to induce predictable inflammatory cytokine responses. The results showed that IL-10 receptor (IL-10R) blockade with an antagonist monoclonal antibody (mAb) dramatically enhanced the LPS-induced cytokine response, thus demonstrating in vivo pharmacologic activity of this immunomodulatory antibody. We submit that this approach could be applied to other cases where the intent of a candidate therapeutic is to modulate components of inflammatory cytokine responses.

Hepatic P-glycoprotein changes with total parenteral nutrition administration.

BACKGROUND: The mechanism(s) responsible for the development of parenteral nutrition-associated liver disease (PNALD) is unknown. Recently, a number of bile canalicular transport proteins have been identified that transport bile components out of hepatocytes. One group of these genes, multidrug resistance 1 (mdr1) and mdr2, encode P-glycoproteins. Mice lacking mdr2 expression develop liver disease that appears similar to PNALD. This study investigated the alteration in the expression of these transport proteins during the administration of total parenteral nutrition (TPN). METHODS: Mice received either physiologic saline and standard chow or TPN. Mice were sacrificed on day 7, and hepatic DNA and RNA content, mRNA expression, and levels of mdr1 and mdr2 proteins were measured. RESULTS: TPN administration led to a significant (p < .05) decline in mdr2 mRNA expression and an increase in mdr1 mRNA expression. Mdr2 protein expression declined by 66% in the TPN-treated group, and mdr1 protein expression significantly increased by 58%. Histology and biochemical parameters showed no evidence of liver injury. Serum bile acid levels were elevated in the TPN group, suggesting the development of early cholestasis. CONCLUSIONS: The decline in mdr2 and rise in mdr1 mRNA and protein expression with TPN administration occurred before the development of liver injury but during an early state of cholestasis. This suggests that alterations in mdr gene expression may be a causative factor in the development of PNALD.

Lymphoid reservoirs of antigen-specific memory T helper cells.

How vaccines control the development of antigen-specific effector and memory T helper cells is central to protective immunity but remains poorly understood. Here we found that protein vaccination selected high-affinity, CXCR5+ICOS(hi) follicular B-helper T cells (T(FH) cells) that developed in draining lymphoid tissue to regulate B cell responses. In the memory phase, reservoirs of antigen-specific CXCR5+ICOS(lo) T(FH) cells persisted with less effector activity but accelerated antigen-recall ability. This new compartment of memory T(FH) cells was retained in draining lymphoid sites with antigen-specific memory B cells, persistent complexes of peptide and major histocompatibility complex class II and continued expression of CD69. Thus, protein vaccination promotes B cell immunity by selecting high-affinity effector T(FH) cells and creating lymphoid reservoirs of antigen-specific memory T(FH) cells in vivo.