The 1st step essential for allergen ‐specific IgE antibody production upon the 2nd step: Induction of non‐specific IgE+ small B cells containing secondly‐sensitized allergen‐specific ones in mice firstly‐sensitized with an allergen

ABSTRACT There was a significant amount of non‐specific, but not of allergen (e.g., papain, mite feces, and 4 kinds of pollen)‐specific, IgE antibodies (Abs) in the serum of normal mice. An intranasal (i.n.) injection of each allergen without adjuvant into mice caused an increase in total IgE Ab titers with a similar time course in the serum; but the stage in the initiation of allergy varied from allergen to allergen. Submandibular lymph node cells from normal mice contained papain‐, but not mite feces‐ or pollen‐specific IgE+ cells; and an i.n. injection of papain induced papain‐specific IgE Abs in the serum. In contrast, 1 (i.n.) or 2 [i.n. and subcutaneous (s.c.)] injections of mite feces induced neither mite feces‐specific IgE+ cells in the lymph nodes nor mite feces‐specific IgE Abs in the serum. An i.n. sensitization with cedar pollen induced cedar pollen‐specific IgE+ small B cells in the lymph nodes on day 10, when non‐specific IgE Ab titers reached a peak in the serum, implying the induction of related allergen‐specific IgE+ small cells as well. In fact, a 2nd (s.c.) injection of ragweed (or cedar) pollen into mice sensitized i.n. once with cedar (or ragweed) pollen, but not with mite feces, induced a large amount of ragweed (or cedar) pollen‐specific IgE Abs in the serum.These results revealed that when non‐specific IgE+ small B cells in the lymph nodes from mice firstly‐sensitized with an allergen contained secondly‐sensitized allergen...
Source: Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research