Lymphocyte Culture: Induction of Colonies by Conditioned Medium from Human Lymphoid Cell Lines

It has been shown that macrophage and granulocyte colonies can be induced m semisolid agar (1-3) in the presence of substances termed colony-stimulating factors (CSF), which are released predominantly by monocytes (4). However, attempts to induce formation of lymphoid colonies with CSF have so far proved unsuccessful. In the mouse, B lymphoid colonies are formed in the presence of 2-mercaptoethanol (5), and T lymphoid colonies can be induced with the plant lectins phytohemagglutinin (PHA) and concanavalin A (6). T lymphoid colonies can also be established from human peripheral blood lymphocytes in the presence of PHA (7-9), whereas with pokeweed mitogen mixed T and B lymphoid colonies are formed (9). Established human lymphoid cell lines multiply spontaneously in the absence of plant lectins or mercaptoethanol, and it seemed possible that such cells might release growth-stimulating substances into the culture medium. We have therefore investigated the ability of conditioned medium (CM) obtained from lymphoid cell lines to induce normal human peripheral blood lymphocytes (PBL) to form lymphoid colonies in agar

Combined Influences of Gm and HLA Phenotypes upon Multiple Sclerosis Susceptibility and Severity

In some Caucasian populations, multiple sclerosis (MS) susceptibility has been independently related to given alleles of HLA or Gm systems that respectively code for major histocompatibility complex class I and II antigens or immunoglobulin G heavy chains. Whether given combinations of alleles at both series of loci simultaneously influence MS susceptibility and/or severity was investigated by comparing 147 French MS patients and 226 geographically-matched healthy controls. The G2m(-23)/HLA-B35 phenotype and Glm(-1)/HLA-B7(-)/HLA-DR2 phenotype were respectively associated with significant protection against (relative risk = 0.05) and susceptibility to (relative risk = 4.3) MS. When considering MS severity, the presence of HLA-B7 antigen correlated with a more severe disease in Gm1/Gm3 heterozygous patients, but not in Gm3/Gm3 homozygous patients. Conversely, an HLA-B12-associated milder disease was restricted to Gm3/Gm3 homozygotes. These results demonstrate the combined influence on MS of genetic loci that are unlinked but immune response-associated. Combined Gm and HLA typing is very likely able to serve as a prognostic indicator in this disease