Biomedical subjects

Sreedevi Kodali

Publications and source records attributed to Sreedevi Kodali.

3 recordsLinked to original sources

PubMed2004

Vasoactive intestinal peptide modulates Langerhans cell immune function.

Epidermal nerves lie in close proximity to Langerhans cells (LC) and are capable of releasing peptides that modulate LC function, including calcitonin gene-related peptide and pituitary adenylate cyclase-activating polypeptide. The neuropeptide vasoactive intestinal peptide (VIP) has also been found in cutaneous nerves and mRNA, for the VIP receptor vasoactive intestinal peptide receptor type 1, and vasoactive intestinal peptide receptor type 2 have been found in murine LC and the LC-like cell line XS106. We examined the effects of VIP on LC function and cutaneous immunity. VIP inhibited elicitation of a delayed-type hypersensitivity response in previously immunized mice by epidermal cells enriched for LC content pulsed with Ag in vitro. VIP also inhibited the ability of unseparated epidermal cells to present Ag to a T cell clone and hybridoma and the ability of highly enriched LCs to present to the T cell clone. Inhibition of presentation to the hybridoma was observed with an antigenic peptide that does not require processing, suggesting that VIP is active at a step independent of Ag processing. To elucidate the mechanism(s) by which VIP may mediate these effects, we determined the effects of VIP on LC cytokine production using the XS106 cell line as a surrogate for LC. VIP augmented the production of the IL-10 in LPS-stimulated XS106 cells while down-regulating IL-12 and IL-1beta production. Thus, VIP, like pituitary adenylate cyclase-activating polypeptide and calcitonin gene-related peptide, down-regulates LC function and the associated immune response.

Animals↗

PubMed2004

Dietary lutein reduces ultraviolet radiation-induced inflammation and immunosuppression.

Ultraviolet radiation (UVR) promotes skin cancer development by mutagenic, immunosuppressive, and oxidative-stress-inducing mechanisms; however, certain antioxidants may counteract and prevent UVR-induced photodamage. Lutein is a xanthophyll carotenoid with potent antioxidant activity. Because reactive oxygen species (ROS) are believed to have a role in UVR-induced skin damage, we investigated whether lutein can modify UVR effects including the tissue swelling response to midrange UVR (280-320 nm, ultraviolet B (UVB) radiation) and UVB suppression of contact hypersensitivity (CHS) in both the local and the systemic models of UV-induced immunosuppression. We found that compared to mice fed the standard laboratory diet, mice fed dietary lutein demonstrated significant inhibition of ear swelling owing to UVB radiation. Mice exposed to 1700 J per m2 UVB radiation four times at daily intervals and then sensitized to dinitrofluorobenzene at the site of irradiation showed a decreased CHS response upon challenge. This suppression by UVB radiation was significantly inhibited by lutein feeding. When UVB radiation was given at a single dose of 10,000 J per m2 to inhibit the induction of CHS at a distant, nonirradiated site, no effect of lutein was seen. Finally, lutein accumulated in the skin of mice following diet supplementation and was shown to decrease ROS generation following UVR exposure. Thus, lutein modulates the skin's response to UVR and may contribute to the defense against some of the deleterious effects of solar radiation.

Animal Feed↗

PubMed2003

Pituitary adenylate cyclase-activating polypeptide inhibits cutaneous immune function.

Epidermal nerves are closely associated with Langerhans cells (LC) and may be able to release factors, such as calcitonin gene-related peptide and epinephrine, that affect LC function. LC and the LC-like cell line XS106 express mRNA for the pituitary adenylate cyclase-activating polypeptide (PACAP) receptors VPAC1 and VPAC2. We examined whether PACAP regulates cutaneous immunity. Intradermal administration of PACAP prior to application of a contact sensitizer at the injected site inhibited the induction of contact hypersensitivity. Pretreatment of murine epidermal cells enriched for LC content (approximately 12% LC) with PACAP inhibited their ability to elicit delayed-type hypersensitivity in previously immunized mice. In vitro, PACAP suppressed the ability of both murine epidermal cells and highly purified LC (approximately 95%) to present antigen to a T cell clone and hybridoma. Furthermore, in LC and the XS106 cell line, PACAP inhibited the LPS/GM-CSF-induced stimulation of IL-1beta secretion and augmented IL-10 production. PACAP also down-regulated CD86 expression in LPS/GM-CSF-stimulated XS106 cells. The immunosuppressive effects of PACAP may be due to modulation of cytokine production and CD86 expression.

Animals↗