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J H Howell

Publications and source records attributed to J H Howell.

22 records · Page 2Linked to original sources
PubMed1978

Micro-leukocyte adherence inhibition. I. Cellular basis of the mechanism of reactivity.

To study the cellular basis for specific antigen-induced leukocyte adherence inhibition, enriched populations of B cells, T cells, and monocytes were prepared by a two-stage adherence separation procedure from spleen cells of normal C57BL/6J mice and mice bearing progressively growing MCA-38 tumors. The reactor cell undergoing specific antigen-induced adherence inhibition was identified as a monocyte (esterase positive, did not respond to mitogens, and did not bear Thy 1.2 antigen or surface immunoglobulin). Furthermore, an enriched population of MCA-38 sensitized B cells could program normal monocytes to undergo specific antigen-induced adherence inhibition. This programming could be abolished by pretreatment of the MCA-38 sensitized B cells with anti-immunoglobulin and complement (indirect cytotoxicity method). In contrast, enriched populations of MCA-38 sensitized T cells could not program normal nylon wool adherent cells to undergo antigen-specific adherence inhibition; and anti-Thy 1.2 serum and complement had no effect on specific antigen-induced adherence inhibition. Thus, in this murine tumor model, leukocyte adherence inhibition appears to be due to the programming of monocytes by sensitized B cells.

Adenocarcinoma↗
PubMed1977

Leukocyte adherence inhibition: an automated microassay demonstrating specific antigen recognition and blocking activity in two murine tumor systems.

This communication describes an automated micro-adherence inhibition assay. Tumor-specific immunity was demonstrated with B16 melanoma and MCA-38 colon adenocarcinoma, both of which are syngeneic to the same strain of mouse (C57B16/J). Abrogation of the leukocyte adherence inhibition (LAI) response of sensitized leukocytes has been demonstrated in the MCA-38 tumor system by the addition of serum from mice bearing MCA-38 progressively growing tumors, a property not present in normal serum. The sensitivity of the system has also been demonstrated by showing that LAI will change prior to a tumor becoming palpable. This microassay has the advantage of being simple, rapid and reproducible, and involves the use of minimal quantities of antigenic preparations and leukocytes, and in addition is amenable to rigorous statistical analysis.

Adenocarcinoma↗