Both Systemic and Mucosal LCMV Immunization Generate Robust Viral-Specific IgG in Mucosal Secretions, But Elicit Poor LCMV-Specific IgA

Abstract

Immunoglobulins in secretions play a critical role in protection at mucosal surfaces. We examined the generation of viral-specific IgG and IgA in plasma and mucosal secretions of mice following systemic or mucosal immunization with lymphocytic choriomeningitis virus (LCMV), a widely used experimental model of viral infection. While there are early differences in humoral responses depending on the route of viral entry, we show that both routes generate comparably robust viral-specific IgG in plasma, vaginal, lung, and nasal secretions of immune mice. In contrast, LCMV elicited poor viral-specific IgA responses. Mice that were infected IN showed elevated viral-specific IgA in nasal and lung washes compared to IP-infected mice; however, LCMV-specific IgG overwhelmingly contributed to the humoral response in all mucosal secretions examined. Thus similarly to HIV-1, and several other mucosally-encountered microbial infections, these data suggest that LCMV infection fails to induce vigorous viral-specific IgA responses.

Cutting Edge: Expression of FcγRIIB Tempers Memory CD8 T Cell Function In Vivo

“…3A). Additionally, when LCMV Arm immune mice (day>70 p.i., when neutralizing IgG antibodies have developed (39)) were challenged with LCMV Arm infected targets (Supplemental Fig. 2B) in the presence of control IgG or 2.4G2 treatment, specific lysis of infected targets was enhanced by 2.4G2 pre-treatment compared to IgG control treated mice (Fig.…”

The regulation of CD8 T cell responses by inflammatory cytokines and FcγRIIB

“…In addition, if immune mice were treated with 2.4G2 mAb to block FcγRIIB stimulation [186,190] prior to transfer of target cells, the specific lysis of cells coated with α-H-2K b +GP 33-41 returned to the level of cells pulsed with GP [33][34][35][36][37][38][39][40][41] alone ( Figure 19B). Additionally, when LCMV Arm immune mice (>70 days p.i., when neutralizing IgG antibodies have developed [191]) were challenged with LCMV Arm infected targets ( Figure 19C…”