Медицинская иммунология (Jul 2014)

ROLE OF DIFFERENT B CELL SUBPOPULATIONS IN IMMUNE RESPONSE TO T-INDEPENDENT TYPE 2 ANTIGENS

  • M. V. Gavrilova,
  • I. N. Chernyshova,
  • E. V. Sidorova

DOI
https://doi.org/10.15789/1563-0625-2007-1-39-46
Journal volume & issue
Vol. 9, no. 1
pp. 39 – 46

Abstract

Read online

Abstract. The role of different B-cell subpopulations in polyclonal B-cell activation induced by T-independent antigens type 2 (TI-2) was under studies. CD5+B/B-1 cells were isolated from the spleens of mice immunized with polyvinyl pirrolidone, or á(1→3) dextran. The numbers of antibody (Ab) and Ig-producers in CD5+B/B-1 splenocytes were determined by ELISPOT. The number of cells producing unspecific Ig was calculated as a difference between the numbers of Ig- and Ab-producers; the numbers of nonspecific Ig-producing splenocytes induced by TI-2 immunization were determined as differences between their contents in immunized and control animals. In experiments with CD5+ and CD5– splenocytic populations, the development of Ab-producers and increased numbers of cells producing unspecific Ig was dependent on the CD5+ B-cells. These data were confirmed in experiments with subpopulations of B-1 and B-2 lymphocytes obtained with Dynal separation kit. In spite of sufficient predominance of B-cells in B-2 fraction (91% vs ~13% in B-1 fraction), the numbers of Ab and TI-2-induced nonspecific Ig-producers were nearly similar for the both cell fractions. Taking into account relative contents of B-cells, the numbers of Aband unspecific Ig- producers in B-1 fraction were 6- to 7-fold higher than in B-2 fraction. Thus, dependence on the B-1 cells exists both for polyclonal immune reactions to polyvinylpirrolidone and dextran, and specific response. Simultaneous injection of two TI-2 antigens did not induce additive effects upon the numbers of unspecific Ig-producers in B-1 fraction, in spite of marked increase in amounts of these cells after separate immunization with either of these antigens. It is concluded that polyclonal activation of B-1 cells by TI-2 antigens is subject to restriction which may depend either on the size of B-cell pool available for activation, or on insufficiency of appropriate stimulating factors.

Keywords