Increases in IgA+ B cells in the Peyer's patches during milk-borne Mouse Mammary Tumor Virus infection are influenced by TLR4 and are completely dependent on the superantigen response

CABRERA GABRIEL; VERCELLI CLAUDIA; BURZYN DALIA; BADANO NOEL; MAGLIOCO ANDREA; COSTA HECTOR; MUNDIÑANO JULIANA; CAMICIA GABRIELA; NEPOMNASCHY IRENE; PIAZZON ISABEL

JOURNAL OF GENERAL VIROLOGY

SOC GENERAL MICROBIOLOGY

Año: 2010 vol. 91 p. 2814 - 2820

0022-1317

Mouse mammary tumor virus (MMTV) is a milk-borne betaretrovirus that has developed strategies to exploit and subvert the host immune system. Although mammary glands are the final target of infection, Peyer´s patches (PP) are the entry site of the virus. Herein, we show that the infection induces increases in the number of PP IgA+ B cells and higher expression of the alfa circular transcript (CTalfa), which is a specific marker of the switch to IgA. In addition, IgA+ B cell increases correlated with higher levels of cytokines related to IgA class switching like interleukin-5 and interleukin-6. Of interest, the increases in IgA+ B cells were lower in toll like receptor 4 deficient mice and were completely dependent on the presence of superantigen reactive T cells. Our results point to a new mechanism involved in MMTV infection and suggest that IgA+ B cells may play an important role carrying the virus to the mammary glands.