Antigen-specific T-lymphocyte function after cord blood transplantation

Area of Science:

• Immunology
• Transplantation Science
• Virology

Background:

• Determining naive T cell contribution to immunity post-hematopoietic stem cell transplantation (HSCT) is challenging due to donor T cells.
• Umbilical cord blood (UCB) offers a unique source of naive T lymphocytes for transplantation.

Purpose of the Study:

• To evaluate the role of naive T lymphocytes in early antigen-specific immune reconstitution after unrelated cord blood transplantation (UCBT).
• To assess the development of T lymphocytes specific for herpesviruses following UCBT.

Main Methods:

• Longitudinal evaluation of UCBT recipients for herpesvirus-specific T lymphocytes.
• Analysis of T cell reconstitution, transplant factors, and graft-versus-host disease (GVHD).

Main Results:

• Antigen-specific T lymphocytes were detected early after UCBT (HSV day 29, CMV day 44, VZV day 94).
• 66 out of 153 UCBT recipients developed T cell responses to at least one herpesvirus.
• Response development was independent of T cell reconstitution, cell dose, disease, or GVHD.

Conclusions:

• Naive T lymphocytes within the hematopoietic stem cell inoculum can initiate antigen-specific T cell immunity early post-transplant.
• UCBT recipients can mount early T cell responses to common viral antigens, highlighting the functional capacity of naive T cells.