Vaccination of human subjects expands both specific and bystander memory T cells but antibody production remains vaccine specific

Abstract

Human subjects maintain long-term immunologic memory against infective organisms but the mechanism is unclear. CD4 ؉ T-helper memory (Th mem )

Bystander stimulation of activated CD4+ T cells of unrelated specificity following a booster vaccination with tetanus toxoid

“…Our earlier study showed that bystander activation of CD4 1 T cells occurs in human subjects during a booster injection of TT, and that the responsive cells were memory T cells specific for other antigens [16]. To probe the bystander power of specific immunity, we have again utilized the TT response.…”

“…Such responses could contribute to the antigen-independent maintenance of T cells at different stages, including memory T cells. Our next goal is to test the effects of bystander stimulation on survival and functionality of transferred memory cells generated in vivo [6] rather than on cells stimulated in vitro, mimicking more closely our observations in human subjects [16]. Whatever the stage of the responding T cells, a balance between maintenance of memory and a potentially pathological effect of cytokine-activated cells must be struck.…”

“…We found that the secondary CD4 1 T-cell responses against the immunizing TT were accompanied by bystander activation and expansion of CD4 1 memory T cells specific for two unrelated antigens, purified protein derivative of tuberculin and Candida albicans. However, there was no effect on the induced antibody responses, which were specific for TT [16]. Interestingly, the bystander activation was confined to pre-existing memory T cells with no effect on naive CD4 1 T cells.…”

Human CD4+ effector T lymphocytes generated upon TCR engagement with self-peptides respond defectively to IL-7 in their transition to memory cells

“…[41][42][43] However, homeostatic maintenance and homeostatic expansion into lymphopenic hosts of naive CD4…”

Characteristics, Detection, and Clinical Relevance of Alloantibodies in Kidney Transplantation

“…More recently, it was reported that sensitized TCs require different DS regimens to reduce DSA levels, including varying the IVIG dose and the number of PP cycles Thielke et al, 2005;Ferrari-Lacraz et al, 2006;Glotz et al, 2004;Rogers et al, 2011). Subsequent studies have demonstrated that susceptibility to IVIG/PP DS depends on immunoregulatory mechanisms, such as polymorphisms in cytokine genes, the frequency of regulatory cells, and hormonal backgrounds (Figure 7) (Glotz et al, 2004;Rogers et al, 2011;Zachary et al, 2003;Bas et al, 1998;Di Genova et al, 2006, 2010Jiang & Lechler, 2003, Amu et al, 2007Anderson et al, 2000;Hill & Sarvetnick, 2002;Kalil et al, 1989;Stasi et al, 2008;Stastny P et al, 2006;Yoo et al, 1995). Furthermore, the efficacy of DS has been reported to be different for DSAs and third-party HLA antibodies.…”