TY - GEN
T1 - The exosporium of B. cereus contains a binding site for gC1qR/p33
T2 - Implication in spore attachment and/or entry
AU - Ghebrehiwet, Berhane
AU - Tantral, Lee
AU - Titmus, Mathew A.
AU - Panessa-Warren, Barbara J.
AU - Tortora, George T.
AU - Wong, Stanislaus S.
AU - Warren, John B.
PY - 2007
Y1 - 2007
N2 - B. cereus, is a member of a genus of aerobic, gram-positive, spore-forming rod-like bacilli, which includes the deadly, B.anthracis. Preliminary experiments have shown that gC1qR binds to B.cereus spores that have been attached to microtiter plates. The present studies were therefore undertaken, to examine if cell surface gC1qR plays a role in B.cereus spore attachment and/or entry. Monolayers of human colon carcinoma (Caco-2) and lung cells were grown to confluency on 6 mm coverslips in shell vials with gentle swirling in a shaker incubator. Then, 2 μ l of a suspension of strain SB460 B.cereus spores (3x108/ml, in sterile water), were added and incubated (1-4 h; 360 C) in the presence or absence of anti-gC1qR mAb-carbon nanoloops. Examination of these cells by EM revealed that: (1) When B. cereus endospores contacted the apical Caco-2 cell surface, or lung cells, gClqR was simultaneously detectable, indicating upregulation of the molecule. (2) In areas showing spore contact with the cell surface, gClqR expression was often adjacent to the spores in association with microvilli (Caco-2 cells) or cytoskeletal projections (lung cells). (3) Furthermore, the exosporia of the activated and germinating spores were often decorated with mAb-nanoloops. These observations were further corroborated by experiments in which B.cereus spores were readily taken up by monocytes and neutrophils, and this uptake was partially inhibited by mAb 60.11, which recognizes the C1q binding site on gC1qR. Taken together, the data suggest a role, for gC1qR at least in the initial stages of spore attachment and/or entry.
AB - B. cereus, is a member of a genus of aerobic, gram-positive, spore-forming rod-like bacilli, which includes the deadly, B.anthracis. Preliminary experiments have shown that gC1qR binds to B.cereus spores that have been attached to microtiter plates. The present studies were therefore undertaken, to examine if cell surface gC1qR plays a role in B.cereus spore attachment and/or entry. Monolayers of human colon carcinoma (Caco-2) and lung cells were grown to confluency on 6 mm coverslips in shell vials with gentle swirling in a shaker incubator. Then, 2 μ l of a suspension of strain SB460 B.cereus spores (3x108/ml, in sterile water), were added and incubated (1-4 h; 360 C) in the presence or absence of anti-gC1qR mAb-carbon nanoloops. Examination of these cells by EM revealed that: (1) When B. cereus endospores contacted the apical Caco-2 cell surface, or lung cells, gClqR was simultaneously detectable, indicating upregulation of the molecule. (2) In areas showing spore contact with the cell surface, gClqR expression was often adjacent to the spores in association with microvilli (Caco-2 cells) or cytoskeletal projections (lung cells). (3) Furthermore, the exosporia of the activated and germinating spores were often decorated with mAb-nanoloops. These observations were further corroborated by experiments in which B.cereus spores were readily taken up by monocytes and neutrophils, and this uptake was partially inhibited by mAb 60.11, which recognizes the C1q binding site on gC1qR. Taken together, the data suggest a role, for gC1qR at least in the initial stages of spore attachment and/or entry.
UR - https://www.scopus.com/pages/publications/84934441980
U2 - 10.1007/978-0-387-71767-8_13
DO - 10.1007/978-0-387-71767-8_13
M3 - Conference contribution
C2 - 17892212
AN - SCOPUS:84934441980
SN - 9780387717654
T3 - Advances in Experimental Medicine and Biology
SP - 181
EP - 197
BT - Current Topics in Innate Immunity
PB - Springer New York
ER -