Tamjidi, Saba

The magnitude of immune responses to vaccination
is a critical factor in determining protection from diseases.
We reported that nicotine disrupts the properties
of DCs that are pivotal in the initiation of immune
response to vaccines. Here we investigated whether
TLR agonist(s) could overcome the effects of nicotine
on human DC and DC-NK cross-talk essential
for effector T cell generation. nicDC, nicDC-NK, and
nicDC-NK-T cultures exposed to TLR agonists were
evaluated for expression of costimulatory molecules,
cytokines, and intracellular cytokine IFN-g using ELISA
and flow cytometry. Our data shows that among
the TLR agonists, TLR3 and TLR8/7 synergistically
optimized nicDC maturation co-cultured NK cell activation.
Importantly, similar to DC-NK, nicDC-NK treated
with TLR3 and TLR8/7 and co-cultured with naïve
T cells promoted a comparable number of effector T
cells. Our data suggest that the addition of appropriate
TLR agonist(s) to vaccine formulation could potentially
improve the smokers’ immune response to
vaccination.

Background: Marine mammals are ideal sentinel species for human health due to exposure to the same oceans and consumption of the same foods. There have been many studies which demonstrate that wild Atlantic Bottlenose Dolphins are exposed to high levels of contaminants which lead to a suppressed immune system and are therefore more susceptible to opportunistic infections, many of which are zoonotic diseases. However, nearly no research has been done on determining defects in the immune cell population of dolphins, especially Dendritic Cells DCs that are essential for initiating an immune response. Hypothesis: We hypothesize phenotypic and functional differences in the Peripheral Blood Mononuclear Cells PBMC, including DC precursors, of wild dolphins as compared to managed dolphins. Methods: Specifically in this study, we have used terrestrial-specific antibodies and growth factors to characterize immune cells in PBMC and to generate monocyte-derived DCs. Results: We have identified cross-reactive terrestrial antibodies that could detect immune cell subsets within PBMC, including B cells, T cells, NK cells, monocytes and APCs. Interestingly, using these antibodies we found significant changes in immune cell subsets within PBMC of wild and managed dolphins. Finally among the terrestrial DC growth factors tested we found rat GM-CSF and IL-4 generated DCs expressing higher levels of CD11c, CD14, CD40, CD80, CD86, MHC I and MHC II. Conclusion: Our findings allow us to further study defects in the immune cells, especially DCs, in response to environmental contaminants.

Background: Vaccines aid in saving lives from infections and biological warfare attacks. They should be effective in all target populations otherwise the likelihood that an unprotected person will transmit disease to a vulnerable individual is greatly increased. There is compelling evidence that smokers are less responsive to vaccination. We have reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine in biological activities of DCs. Using in vitro mouse culture system we have identified an appropriate TLR agonist capable of correcting the defects in DCs exposed to nicotine. Hypothesis: In order to translate these studies to human, we tested the hypothesis that appropriate TLR agonists will also correct the degrading effects of nicotine on human DCs and consequently DC-NK cross talk and T cell polarization. Methods: Monocyte-derived DCs were generated in culture media containing growth factors GM-CSF and IL-4 with or without nicotine treatment. DCs were activated with indicated TLR agonists and their phenotypes and cytokine profiles were analyzed by flow cytometry and ELISA, respectively. Results: Among the TLR agonists tested, we found that nicotine has less effect on human DC maturation in response to TLR4 plus TLR7/8 agonists as evidenced by expression levels of their costimulatory CD80/83/86/40 and antigen-presenting HLA-DR molecules as well as inflammatory cytokines IL-12, IL-10,TNF-α and IL-1β production. Conclusion: We are currently investigating whether these TLR agonists also augment human DC-NK bidirectional signals essential for T cell differentiation in a nicotinic environment.

There is compelling evidence that smokers are less responsive to vaccination. We reported that both therapeutic and prophylactic vaccines fail to protect and cure animals from disease due to negative effects of nicotine on DCs’ ability to generate effector T cells. We have been investigating whether vaccine formulated with TLR agonist(s) could potentially overcome the immunosuppressive effects of nicotine on human DC-NK cross-talk essential for effector T cell generation. Monocyte-derived DCs and nicDCs were stimulated with individual and combined TLR agonists prior to co-culture with purified T cells. The phenotypes and cytokine profiles of T cell were assessed using Flow Cytometry and ELISA, respectively. We found nicDCs cultured with TLR-8/7 alone or in combination with TLR-3 produce quantitatively and qualitatively similar IFN-γ producing effector T cells when compared to control DCs. Our data suggest that the addition of appropriate TLR agonist to vaccine formulation could potentially overcome the immunosuppression seen in smokers, thereby containing the spread of infectious disease to vulnerable population