Lymphotactin acts as an innate mucosal adjuvant

Area of Science:

• Immunology
• Cellular and Molecular Immunology
• Mucosal Immunity

Background:

• Lymphotactin (Lptn) is a C-chemokine produced by NK and T cells, including gammadelta TCR+ intraepithelial lymphocytes.
• Lptn attracts NK and T cells, playing a role in epithelial integrity and mucosal immune responses.

Purpose of the Study:

• To investigate the immune-enhancing properties of Lptn when administered with ovalbumin (OVA) via intranasal immunization in mice.
• To characterize the effects of Lptn on both systemic and mucosal adaptive immune responses.

Main Methods:

• Mice were intranasally immunized with OVA in the presence or absence of Lptn.
• OVA-specific antibody (Ab) responses in serum and mucosal secretions were measured.
• OVA-specific Ab-forming cells were quantified in mucosal and systemic compartments.
• CD4+ T cell proliferation and cytokine production (IFN-gamma, IL-2, IL-4, IL-5, IL-6, IL-10) were assessed.

Main Results:

• Intranasal administration of OVA with Lptn significantly enhanced OVA-specific serum Ab responses and mucosal Ab titers.
• Lptn increased the number of OVA-specific Ab-forming cells in both mucosal and systemic sites.
• CD4+ T cells from Lptn-treated mice exhibited heightened OVA-specific proliferation and produced higher levels of key cytokines, indicative of Th1 and Th2 responses.

Conclusions:

• Lymphotactin (Lptn) demonstrates significant adjuvant properties, enhancing both humoral and cellular immune responses.
• Lptn has the potential to augment mucosal and systemic antibody production by promoting Th1 and Th2 cell-mediated help.
• Lptn serves as a crucial link between innate mucosal signals and the adaptive immune system.